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Surpac Minex Group Pit design
in Surpac Vision
July 2006
Copyright © 2006 Surpac Minex Group Pty Ltd. All rights reserved. This software and documentation is proprietary to Surpac Minex Group Pty Ltd. Surpac Minex Group Pty Ltd publishes this documentation for the sole use of Surpac licenses. Without written permission you may not sell, reproduce, store in a retrieval system, or transmit any part of the documentation. For such permission, or to obtain extra copies please contact your local Surpac Minex Group Office. Surpac Minex Group Pty Ltd Level 8 190 St Georges Terrace Perth, Western Australia 6000 Telephone: (08) 94201383 Fax: (08) 94201350 While every precaution has been taken in the preparation of this manual, we assume no responsibility for errors or omissions. Neither is any liability assumed for damage resulting from the use of the information contained herein. All brand and product names are trademarks or registered trademarks of there respective companies. About This Manual This manual has been designed to provide a practical guide to the many uses of the software. The applications contained within this manual are by no means exhaustive as the possible uses of the software are only limited by the user’s imagination. However, it will give new users a starting point and existing users a good overview by demonstrating how to use may of the functions in Surpac Vision. If you have any difficulties or questions while working through this manual feel free to contact your local Surpac Minex Group Office. Author Rowdy Bristol Surpac Minex Group Perth, Western Australia Product Surpac Vision v5.1
Table of Contents Introduction ................................................................................................................................ 1 Requirements ............................................................................................................................ 1 Objectives .................................................................................................................................. 1 Workflow .................................................................................................................................... 1 Pit Design Data Preparation ...................................................................................................... 2 Basic Pit Design Tools............................................................................................................. 18 Additional Pit Design Tools...................................................................................................... 39 Pit Design to Surface............................................................................................................... 49 Pit Design to Surface Model .................................................................................................... 60 Visualisation............................................................................................................................. 78 Waste Dump Design................................................................................................................ 90
Introduction This tutorial shows the procedures for generating Pit and Dump Designs using the Surpac Vision. The tutorial focuses on the use of the new `Pit design' functions first released in Version 3.1 of Surpac Vision, and which constitute a complete rewrite of the older `Pit and Dump' design tools. The result is a significantly higher level of flexibility, ease of use, as well as significantly higher levels of functionality throughout. Of particular note are that the Pit design give the user greater control over ramp to berm access, incorporate interaction with DTM surfaces and allow various options for conditional berm creation.
Requirements This tutorial is written assuming users have a basic knowledge of Surpac Vision. We recommend that Users be at least comfortable with the procedures and concepts in the Principles of Surpac Vision training manual. If you are a new Surpac Vision user, you should go through the Principles of Surpac Vision training manual before going through this manual.
Prior to proceeding with this tutorial, you will need:
• Surpac Vision v5.1 installed • The data set accompanying this tutorial
Objectives
The objective of this tutorial is to allow you to create a Pit Design. It is not intended to be exhaustive in scope, but will show the work flow needed to achieve a final result. You can then refine and add to this workflow to meet your specific requirements.
Workflow The process described in this tutorial is outlined below:
• Pit Design Data Presentation • Basic Pit Design Tools • Additional Pit Design Tools • Pit Design to Surface • Pit Design to Surface Model • Visualisation • Waste Dump Design
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Pit Design Data Preparation
Overview
In this section we will look at how to prepare the data required to design an open pit mine in Surpac Vision. Before starting a pit design you need to prepare data to guide the design. This data can be obtained from various sources and may be in various formats. This section will cover the topics listed below:
• Geology outlines • Whittle outlines from the Whittle string file interface • Whittle outlines from the Whittle-Surpac Block model interface • Surpac Vision constrained Block models • Natural surface data • Geotechnical design constraints • Mining fleet design constraints
Geological Outlines The purpose of this section is to review the basic data sources used in pit design. Start Surpac Vision and change the working directory to the pitdes training directory. To do this you can right click in the navigator pane and choose the change directory icon. The training data is supplied with Surpac Vision and can be installed as an option when installing the software. If the data is not installed, insert the Surpac Vision CD and run the install program. The data is installed by default into the directory \dem\training\pitdes. Open the file zon1.str in the graphics workspace by dragging it into Graphics. This file contains a range of geological slices taken through a solid of an ore body. Use the viewing function View Viewing planes, define viewing planes to define a viewing slice of the data. Select a viewing slice thickness of 10 metres. Use the viewing function View Viewing planes Step plane backwards and Step plane forwards to move the viewing slice through the data. Use the View Viewing planes and then Remove viewing / cutting planes to restore the initial view of the data. Geological outlines are a good source of information when performing pit design. They can be obtained from slicing a geological model (solid or wireframe) or taken from bench by bench interpretations.
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1. Whittle outlines from the Whittle string file interface In this section we will examine the basic data sources to be used in the pit design.
In the last exercise we reviewed geological outlines that can be used as a guide in pit design. The outlines indicate the ore zones but may not be optimal for the removal of all these zones. The cost of processing the waste may outstrip the revenue obtained from the ore.
Under Mining tools, Surpac Vision has an interface to Whittle 3D and 4D which allows the output of data from Surpac Vision to Whittle and the conversion of the Whittle results in Surpac Vision string files.
Open the file whit16.str into a layer called whittle16. The following image will be displayed.
whit16.str is one of two Whittle output files we will use for the pit design. When viewing the file in graphics, you will see that it already forms the basis of a pit design.
Open the file whit28.str into a layer called whittle28. Note: The option to replace or append will not have any effect because the files are in different layers.
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Type the word layers and press enter. The following form displays the layers that are active in memory:
You can control which layers are visible, selectable and active. Note that the active layer is the only layer that can be modified. Layers act like transparencies on a light table, with the layer on top being the only one you can draw on. An understanding of the layer functions in Surpac Vision is an important part of design work. You may want to use the two whittle files because they represent a two stage pit design. In this case, whittle16 will be mined first and then a cutback will be done to mine whittle28. Whittle28 is mainly an expansion of whittle16 to the south with only a little area remaining in the north that would not be practical to mine in the cutback. By comparing the two files during the pit design, any part of whittle28 to the north could be included in whittle16 and mined at the same time.
From the File menu, select Reset graphics to clear all layers then return to graphics and open wmod915.str.
This file is a combination of whittle16, whittle28 and the geological outlines at the 995 elevation.
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2. Whittle Outlines from the Surpac Vision Block Model From the File menu, select Reset graphics. From the Block model menu, select Block model, then New/ Open. Enter the model name pitdesign and apply the form. From the Block model menu, select Block model, then Display and apply the form that is displayed. The Pitdesign block Model is now displayed. From the Block model menu, select Constraints then New graphical constraint file, enter the information as shown below and Apply the form.
Note the use of the constraint combination a or b which means a value must satisfy block constraint a or b, the default is a and b. In this case, if we used a and b we would get nothing as the block attribute pit number cannot satisfy both conditions. Use the viewer to inspect the model when pit number attribute is returned from the Whittle optimization. The model you see is the same as the whit16.str file we reviewed previously. From the Block model menu, select Constraints, then Remove all graphical constraints.
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From the Block model menu, select Constraints, then New graphical constraint.
The Whittle pit shell 16 and 28 will now be displayed.
From the Block model menu, select Display, then Colour model by attribute, and enter the information as shown. Make sure the colour index table is filled in up to colour number 30.
The two Whittle pit shells 16 and 28 can now be seen displayed in different colours.
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From the Block model menu, select Export, then Block faces to DTM. Enter the values as shown below, then Apply the form.
This function makes it possible to create a DTM file by using the exterior faces of the block model (inside the current constraint) to create a set of triangles. This DTM representation of the block model image may then be processed by either the Contour Extract function from the DTM Tools menu or the Slice Object function from the Solids menu to create a range of outlines. Exit the Block model and open pit28.dtm. From the main menu choose Display then 2D grid. From the main menu choose View, Data view options then Section view From the Solids menu, select Solids tools, then Create sections. The Define an Axis Line form will be displayed, for axis start y=0, x=0 and z=800, for axis end y=0, x=0 and z=1100. This will give a vertical axis for the DTM.
The Extract Slices Through Objects form is now displayed. Enter the parameters as shown below.
There are two results produced by the Slice Object function. The first result is a range of string files called wmb885 to wmb1085 in increments of 10 which contain the extracted sections. These files are saved to disk. The second result is a layer called slice which contains the extracted sections. If required, you can activate this layer and save all the sections to a single file.
The files written to disk are in sectional coordinates. In this case they are the same as real world coordinates. If you use a different axis, e.g. north south and want real world coordinates, save the sections written to the separate layer, in this case called slice.
Using the method described above you have created a set of outlines for the Whittle pit shell 28. By constraining the block model with only pit number 16 you could follow the same procedure to produce outlines of Whittle pit shell 16.
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Other methods for creating surfaces in the block model, such as ISO surfaces, can be used where your model has many internal voids. Refer to the Online Reference Manual for assistance on how to use ISO surfaces.
3. Surpac Vision Constrained Block Model
This section describes how to use a constrained block model as a guide in pit design.
A constrained block model is simply a block model which contains a subset of the blocks from a parent model. You can perform all the usual block model functions on a constrained model, and even merge it back into its parent. This facility is particularly useful when wanting to work on only a portion of a much larger parent model.
One of the advantages of using block modelling as opposed to string modelling for the geological model is the ability to visualize the geological model. Below are two views of the geological model which have been coloured on gold grade. This is the same model we used in the previous excises to create outlines of the Whittle pit shells. The geological values are stored in separate attributes called gold, silver and geology.
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In the following image the geology is viewed from the South West.
With the Whittle pit number stored directly in the block model, it is easier to visualize the different Whittle pits,
From the File menu, select Reset graphics. From the Block Model menu, select Block model, then New / Open, complete the following form then choose Apply.
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From the Block Model menu, select Constraints, then New constraint file, complete the following form, and then choose Apply.
We can now use this constraint when we load the model next time. Exit the Block Model then choose Block Model. This time we will load the constrained model. Rather than loading the whole model into memory and then constraining it to Whittle pit 28, it is more efficient to simply load the constrained model. The ability to load constrained block models greatly increases memory efficiency.
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On the next form, choose Apply without changing any defaults, as shown below:
Complete the constraints form as shown below. This will load all blocks for Whittle pit shells up to and including whittle shell 28.
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This is the constraint we created previously, so only those blocks that satisfy the constraint will be loaded into memory. From the Block model menu, select Block model, then Display and Apply the form to display the model. From the Block model menu, select Display, then Colour model by attribute. Complete the form as shown below.
This will colour the block model according to the following colour scale: Initially the screen will look like the following image.
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This shows all blocks in the 28 pit, coloured on gold grade. Most blocks are coloured pink, because they are outside of the vein material and therefore have no grade assigned to them (ie. they are waste blocks). As we will be designing from the bottom up, to start the design we wish to show the Whittle outline and geological model at the base of the pit.
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From the Block model menu, select Constraints, then New graphical constraint, and fill the form out as shown below.
Note that the above constraint will suffice, since the lowest elevation of the blocks in the model is 880. To constrain between levels we would use:
NOT ABOVE Z PLANE 900
ABOVE Z PLANE 890
Window In on the displayed blocks. Draw a 2D Grid. The following image should be present on your screen:
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This shows all the blocks within Pit 28, between 880 and 890 elevations, coloured on gold grade. Next, we wish to look at which blocks belong to the 16 pit and which belong to the 28 pit. From the Block model menu, select Display, then Colour model by attribute. Complete the form as shown below.
The block model is now coloured on pit number as shown below:
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4. Natural Surface Data
This section describes how to use natural surface data in pit design.
From the File menu, select Reset graphics and close the block model. Then open top1.dtm. Turn hide on, edges off and lights on. Complete and Apply the form as shown below.
This is the natural surface we will use in our design. We will use the viewing tools to observe the data.
In pit tools you can design up or down to a DTM surface. Note that the DTM may be the natural surface or a natural surface and an old pit combined. Pit tools give many options to control berm and crest creation while interacting with DTM surfaces. The options mentioned below are an outline of some of the tools which will be used when creating berms and crests in this manual.
Delta z up to DTM >= This option can be used when expanding the pit design upwards. For example, if you use a value of 5 meters for the `delta z limit' field then a berm will be created whenever the distance from the last crest up to the DTM is greater than or equal to 5 meters.
Delta z down to DTM >= This option is used when building a Dump from the top and expanding the design downwards. For example, if you use a value of 5 meters for the `delta z limit' field then a berm will be created whenever the distance from the last crest down to the DTM is greater than or equal to 5 meters.
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Delta z to DTM (ie. do not specify whether we are expecting to travel up or down to the surface). This is useful when using the Pit tools for designing a road where a string defines the road surface and the Pit tools are used to create the batter angles which may go up or down depending on whether the road is higher or lower than the DTM surface.
5. Geotechnical Design Constraints
This section will show the effects of geotechnical conditions on the design and how to allow for them.
Design Slopes
If you have carried out an optimization with Whittle, you may have made some considerations for batter slopes. In Pit Tools there are three ways that batter slopes can be applied:
• Design Slope
A constant wall slope around the whole pit. Note: This can be changed during the design process.
• Descriptions
The slope is stored in the first description field of each point on the segment to be expanded. This allows for great flexibility in varying the batter angles around the pit.
This option is particularly useful when different sides of the pit require different slope angles. This is common when one side of the pit is low strength material and requires shallower slopes than the remainder of the pit. Note that precise placement of slope strings can be difficult in this case.
• Slope Strings
This method obtains the slope angle to be used, for each point in the segment being expanded, by reading the slope angle from the D1 field of the slope string which encompasses the point in question.
It is a simple matter to change the pit wall slope angles at any time during the design process.
Ramps
Ramp position in the pit design is normally allowed for, in the optimisation process. Items to consider may include the ramp start and end points, which pit wall the ramp will be on, switch backs, and more. Pit tools has many built in features to assist and customise ramp design. Some of the main features are listed below.
• Ramp name
You may have many ramps in the pit and this name is to help you manage which ramp's characteristics you may be changing during the design.
• Ramp type
There are 3 possible ramp types, clockwise, anti-clockwise and all cut. An all cut ramp is often used to start access into the pit, for excavations or as an all fill ramp for waste dumps.
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• Ramp Gradient Method
Defines where the ramp gradient will be calculated. Choices here include inside edge, outside edge and centre of ramp.
• Berm Crossing Method
This determines the berm characteristics where the ramp crosses the berm. Valid choices here are exit at crest, exit at toe, exit at crest and toe, and no berm exit. The most common method is 'exit at toe', allowing for the berm to be accessed from the ramp at the ramp toe.
Note: Further information can be obtained from the Online Reference Manual.
Mining fleet design constraints
The type of mining equipment to be used can have a considerable effect on the pit design. Details concerning what type of equipment to use and why is outside the scope of this manual. However, it is important that these constraints are given consideration in the design process. Among the many points to consider relating to mining equipment touched on in this manual, are ramp gradient, ramp width and critical radius on turning circles.
Summary
The above information has been provided to assist with the preparation of data for mine design using the Surpac Vision Pit Tools. You should now be familiar with the following:
• Geology outlines • Whittle outlines from the Whittle string file interface • Whittle outlines from the Whittle-Surpac Block model interface • Surpac Vision constrained Block models • Natural surface data • Geotechnical design constraints • Mining fleet design constraints
The information in this section forms the framework for the rest of the tutorial. If you are unclear on any of the above items please review this section.
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Basic Pit Design Tools Overview
This section of the manual will take you through the first stage of designing a simple pit. The design will be based on optimised pit shells from Whittle and an orebody model, both contained within a Surpac Vision block model. The design will include such features as:
• Using a constrained block model for design • Defining the pit base • Defining slopes and berm widths • Defining ramps and access from ramp to berm • Creating crests and toes • Editing the design
In this exercise we will apply the information we covered when preparing the data for pit design.
1. Loading the Constrained Block Model We will now load the block model containing the orebody and Whittle data, colour it by grade and then constrain the model to show the blocks on the lowest bench at midbench level 885. From the Block model menu, select New/Open. Complete the form as shown below. This is the constrained model we used in the previous section.
Complete the constraints form as shown below, which will then load all blocks for Whittle pit 28.
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Only those blocks that are inside the constraint will be loaded into memory. From the Block model menu, select Display, and Apply the form to draw the block model. Select the macro record icon and, enter the name grade and Apply the form. We will use this macro latter to change views of the data. From the Block model menu, select Display, then Colour model by attribute. Complete the form as shown below.
From the Block model menu, select Constraints, then New graphical constraint file and enter the information as shown below and Apply the form.
This shows all the blocks within Pit #28, between 880 and 890 elevations, coloured on gold grade. Next we wish to look at which blocks belong to the 16 pit and which belong to the 28 pit.
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Select the macro record icon to record a macro, enter the name pits and Apply the form. From the Block model menu, select Display, then Colour model by attribute. Complete the form as shown below.
Select the macro record icon to stop recording the macro. You can change between the two views of the data by typing macro:grade or macro:pits at the function prompt. From previous analysis of the Whittle pit shells, we have decided to design the pit in two phases. The first phase will be to the limits of Pit #16 to the south, and Pit #28 to the west, north and east. T he second phase of the pit design will be a push back to the south of the first phase design to excavate the material between Whittle Pit #16 and 28. If you want to see all of the steps performed in this chapter, either run or edit:
01_load_constrained_blockmodel.tcl Note: You will need to Apply the forms which are presented.
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2. Defining the Starting String The first step is to design a starting string. If we are designing from the top down, as is often the case in quarries, the string could be a lease boundary. In this case we will be mining from the bottom up so we will use a digitised string based on information from the whittle model.
So that we start from the same base, we will use the one provided with the tutorial. Remember, when designing the base of the pit, the minimum pit width must be taken into account.
Open the file bas880.str into the graphics workspace. By default it will be in the Main Graphics Layer. (if opened via the navigator it should be in a layer of the same name as the file) The block model is on its own layer and is not affected by opening files. From the Main menu, choose View, Zoom and then Out once. You should now be able to see the whole base outline. The base is at an elevation of 880 and the blocks are between 880 and 890. For this reason, if we had left Hide On we would not be able to see the base where it passes below the blocks. With Hide Off, you should be able to see your whole outline, as shown below. Window In (alias WI) to the view shown.
Reset the block colour to reflect grades using the command macro: grade typed at the function prompt. If you want to see all of the steps performed in this chapter, either run or edit:
02_load_base_string.tcl Note: You will need to Apply the forms presented.
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3. Defining Slopes and Berm Widths We now wish to select the slope method to be used during the pit design. Right click the menu/toolbar area to display the menu/toolbar context menu. Select the surface design menu.
Right click the menu/toolbar area to display the menu/toolbar context menu. Select the surface design toolbar.
As discussed in the previous chapter, we need to select a slope method to set the batter angles. We have slope strings already defined from the first pit design exercise so we will use this slope string file, slo1.str.
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From the Pit design menu, choose Select slope method, then Slope strings on the form displayed.
From Pit design menu, select Load slope strings, then enter the values as shown below and Apply the form.
The slope strings have a value in the first description field that defines the batter angle to be applied within that polygon.
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To make the slope strings invisible just set the appropriate layer to not visible as shown below.
The final task we must perform before starting the pit design is to define any ramps. We do this by using the Define Ramps function. If you want to see all of the steps performed in this chapter, either run or edit:
03_define_slope_berm_width.tcl Note: You will need to Apply the forms which are presented.
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4. Defining Ramps In this section we will define ramp parameters. From the Pit design menu, select New ramp, and select the two ramp entry points as shown below. Note that the order in which you select these points is not important. Take note of the geometry of the ramp start position on the base string. The geometry is determined by the width of the required ramp.
The Define a New Ramp form is displayed. Complete the form as shown below. Before applying the form, it is worthwhile to read the following section for a definition of each option.
• Ramp name
You may have many ramps in the pit and this name is used to help you manage which of the ramp's characteristics you may be changing later on.
• Ramp String
You may specify the string number for the ramp edges. Both sides of the ramp will have this string number, with distinct segments used to represent each side of the ramp.
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• Ramp type
There are 3 possible ramp types:
• Clockwise - This is a circular ramp which will be generated in a clockwise fashion around the segment as it is expanded/contracted from one level to the next.
• Anti-clockwise - This is a circular ramp that will be generated in an anticlockwise fashion around the segment as it is expanded/contracted from one level to the next.
• All cut - This is a ramp which will be created as an all cut ramp (for excavations), or as an all fill ramp (for waste dumps). A further requirement for this type of ramp is that you must select a segment which defines the path along which the ramp must follow as the design progresses from one level to the next. This segment is commonly referred to as the centre line segment for the all cut ramp. The elevation of this segment has no influence on the elevations of the points which represent the ramp as it is created. The elevations of points on the ramp are determined as the design progresses from one level to the next using the ramp grade and starting elevation.
• Ramp width
The width of the ramp. This field has a default value, rounded to the nearest unit, of the distance between the 2 selected points. This may prove a useful aid in ensuring that the correct points have been selected.
• Ramp gradient
The gradient is defined as a ratio; therefore entering a value of 10 will produce a ramp with a gradient of 1 in 10, or 10%.
• Gradient Method
Valid choices here are inside edge, outside edge and centre of ramp.
Valid choices for the gradient calculation method for circular ramps are:
• Inside edge.
The ramp gradient is calculated along the inside edge of any curves in the ramp. The inside edge is the shortest path from the start of the ramp to the end of the ramp. This is the most commonly used method, and has the advantage that the ramp gradient will never exceed the maximum permissible gradient. This is important when considering safety issues.
• Outside edge.
The ramp gradient is calculated along the outside edge of any curves in the ramp. This may be desirable in circumstances where the ramp gradient must not be less than the design gradient. The outside edge will cause the ramp elevations to be calculated using the ramp gradient and the longest path from the start of the ramp to the end of the ramp.
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• Centre of ramp.
This ramp gradient is calculated along the centre of the ramp that is half way between the two edges of the ramp. This method will minimise the deviation of the ramp gradient from the design gradient.
• Berm Crossing Method
This determines the berm characteristics where the ramp crosses the berm. Valid choices here are exit at crest, exit at toe, exit at crest and toe, and no berm exit. The most common method is exit at toe, allowing for the berm to be accessed from the ramp at the ramp toe.
• Exit at crest.
This berm crossing method ensures that the ramp and pit wall geometry will be created so that it is possible to exit the ramp on the crest side of the ramp and drive onto the berm.
• Exit at toe.
This berm crossing method ensures that the ramp and pit wall geometry will be created so that it is possible to exit the ramp on the toe side of the ramp and drive onto the berm.
• Exit at crest and toe.
This berm crossing method ensures that the ramp and pit wall geometry will be created so that it is possible to exit the ramp on both the toe and crest sides of the ramp and drive onto the berm.
• No berm exit.
This berm crossing method will create the ramp and pit wall geometry so that it is not possible to exit the berm from the ramp.
• Berm Taper Distance
If the berm crossing method is not exit at crest and toe, then the berm tapers to zero width at one or both sides of the ramp at each berm. The berm taper distance is the distance along the ramp (from the ramp crossing point) that the berm starts to taper. The berm tapers linearly from the full berm width at the berm taper distance to zero at the berm crossing point. It is important that the berm taper distance is appropriate for the design conditions. The berm taper distance must not be greater than half the distance between successive berm crossings otherwise the adjustments made at one berm crossing will be unduly influenced by the adjustments made at the next or previous berm crossing.
Apply the Define a New Ramp form. We are now ready to start creating the pit outlines. If you want to see all of the steps performed in this chapter, either run or edit:
04_define_new_ramp.tcl Note: You will need to Apply the forms which are presented.
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5. Creating Crests and Toes In this section we will incrementally design the pit, bench by bench, to the 920 metre level. From the Expand string menu, select Bench height, and complete the form as shown below:
The expand string functions will perform the task for all segments of the selected string while the expand segment functions will operate on only the selected segment. Both options will work on closed or open strings. The base is expanded up by 10 metres vertically at the slope angles defined in the slopes string file, and the ramp is designed anti-clockwise at the gradient of 15%, as shown below:
When designing pits from the base up, if any pit outlines are to be modified, (eg. to capture more ore) it is always the toe outline that is adjusted. Adjusting the crest outline would result in changing the pit slope angle which is generally undesirable.
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From the Expand string menu, select By berm width, and complete the form as shown below. This will create a 5 metre berm.
In addition to defining berms of fixed width around the whole pit, berm widths can also be taken from the slope string file or from the second description field of all points on the outline being expanded. In this way berm widths can vary in different positions in the pit. The result of the berm width function is shown below. Note the different berm crossing characteristics at the ramp crest and toe.
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Before we decide whether to adjust this toe outline in order to match the Whittle pit as closely as possible, we should show the Whittle pit blocks and geology on the bench above, ie. the blocks between 890 and 900. Each time you expand a string or segment it is good practice to check the resulting line for any undesirable geometry. It is most common in areas where the pit outline contracts rather than expands at the apex of acute angles which may develop or anywhere the outline has a high level of curvature. These instances may be corrected using the regular string editing tools during the design. From the Block model menu, select Constraints, then Remove last graphical constraint. This removes the last added constraint and in this case will bring back all pit 28 blocks. From the Block model menu, select Constraints, then New graphical constraint and complete the form as follows.
The screen is updated, as shown below:
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We will go up one more bench before extending our pit outline to the north in order to capture the ore which is outside the present pit outline. Return to the Pit Tools menu. From the Expand String menu, select By bench height. The default values are the last entered values and therefore are correct for a 10 metre bench height.
From the Expand String menu, select By berm width. The default values are the last entered values and therefore are correct for a 5 metre berm width.
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The following result will appear:
In this instance, a small concave face has been formed on the east side of the pit. You may wish to use the string editing tools (point move) to straighten the wall as shown.
Next we wish to show the Whittle pit blocks and geological model from 900 to 910 elevations.
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From the Block model menu, select Constraints, then Remove last graphical constraint. This removes the last added constraint and in this case will bring back all pit 28 blocks. From the Block model menu, select Constraints, then New graphical constraint file and enter the information as shown below and Apply the form.
The screen will be updated as shown below:
The outline of the Pit at the current level may be edited using Surpac's regular editing tools at any time during the design process. As mentioned earlier, modifying the design usually takes place following expand by berm width, to ensure a valid design is maintained. If you want to see all of the steps performed in this chapter, either run or edit:
05_expand_bench_height_berm_width.tcl Note: You will need to Apply the forms which are presented.
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6. Editing the design We will now adjust the toe outline at the 900 elevation to capture the ore to the north of the pit, and then proceed to the 920 elevation toe. From the Edit menu, select a combination of the Point Move and Point Insert functions to move and create points on the 900 toe outline until the toe resembles the image below. When adjusting the toe outline interactively in this manner, it is important to maintain the minimum mining width.
The different colour strings may be hard to see on the coloured ore. You can change your colour settings so all of your strings are shown with a more suitable combination. Whenever you wish all the strings in a file to be displayed as a certain style, it is simply a matter of recalling the new styles file (ie. something like ssi_styles:design_style.ssi) from the Display properties or when opening a file from the open file form. If you want the new one all the time change it in the defaults.ssi file using Customise Default preferences. Now we will adjust our toe outline at the 910 elevation to capture the ore to the north of the pit. From the Expand String menu, select By bench height. The default values are the last entered values and therefore are correct for a 10 metre bench height. From the Expand String menu, select By berm width. The default values are the last entered values and therefore are correct for a 5 metre berm width.
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The results are shown below:
You may wish to edit the concave outline shown by the arrow. This is done to prevent undesirable and impractical pit wall geometries from being created. Deleting a point on each of the three lines will achieve the desired result, as shown below:
From the Block model menu, select Constraints, then Remove last graphical constraint. This removes the last added constraint and in this case will bring back all pit 28 blocks.
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From the Block model menu, select Constraints, then New graphical constraint and constrain the block model between Z Planes of 910 and 920, (ie. not above 920 and above 910). The screen should look as shown below:
From the Edit menu, select a combination of the Point Move and Point Insert functions to move and create points on the 910 toe outline until the toe looks approximately as shown below. Note: You can use your own skills to shape these changes as you see fit. The images shown here are only a guide.
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When adjusting the toe outline interactively in this manner, it is important to maintain the minimum mining width. We will now widen our ramp to 20 meters and change its gradient to 10%, in preparation for a switchback.
Note: The Undo and Redo functions work extremely well with the Pit Tools module. If geometrical problems are encountered during the design, simply undo the last function and then fix the area that caused the problem. Re-invoke the function and the new outline should be created without the geometrical problem. This is a much better technique than trying to fix the geometrical problem by editing the string after the problem occurs. From the Pit design menu, select Ramp properties, then select any point on the outermost pit outline (the 910 toe). The following form will be displayed. Change the width to 20 and the gradient to 10. In preparation for the upcoming switchback we also wish to change the Berm crossing method to exit at crest so we will still have a way to access the berm after putting in the switchback.
Proceed to the 920 elevation toe, choosing Expand string by bench height followed by Expand string By berm width. The ramp will be wider and have a shallower gradient.
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From the Block model menu, select Constraints, then Remove last graphical constraint. From the Block model menu, select Constraints, then New graphical constraint, to show the block model between 920 and 930. The screen should be similar to the following:
From the File menu, select Save, then string/DTM, to save the design as pit920.str. When performing the pit design, newly created design data is retained in memory only, and saved to the hard drive only when the Save File function is explicitly chosen. To avoid the potential loss of work, your pit design should be saved regularly using the Save File function. If you want to see all of the steps performed in this chapter, either run or edit:
06_edit_design_and_ramp.tcl Note: You will need to Apply the forms which are presented.
Summary
You should now be familiar with the following parts of pit design:
• Using a constrained block model in pit design • Defining the pit base, (starting string) • Defining and applying slopes and berm widths • Defining and creating ramps and access from ramp to berm • Creating crests and toes • Editing the design
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Additional Pit Design Tools
Overview
The Pit Tools module allows a great deal of flexibility in its use. Designs can be saved, left and restarted at any time. As already shown, this module can be used with other functions and modules in Surpac Vision. In this section we will use this flexibility to continue the pit design. This section will take you through the second stage of the design of a simple pit. In this section we will restart the design and add some switch backs. The design will include such features as:
• Restarting a Pit design • Designing a switch back • Correcting geometry problems
The design started in the previous section will be used in the following exercises.
1. Restarting a pit design Reset graphics to clear any data from the workspace. Change directories (right click in the navigator) to where you were doing the pit design. By default it will be something like c:\ssi_v5.1 \dem\training\pitdes. Open pit920.str. Remember to change the styles file if necessary. From the Block model menu, select New/open, and fill in the form as shown below. Please note that this time we are loading the constrained model we created in the previous section.
From the Block model menu, select Display, then invoke macro:grade.tcl to set the colours. From the Block model menu, select Constraints, then New graphical constraint file and constrain the model between the 930 and 920 elevations. From the Pit design menu, choose Select slope method, and then Slope strings on the form displayed. From Pit design menu, select Load slope strings, then enter the Location as slo1.str, check the Display strings check box and Apply the form.
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This will put the slope strings in a separate layer called slope strings layer. We are now back to where we were before resetting Graphics. The next step will be to define the ramp and continue with the design. Before we do that we will modify the pit by using the design tools to insert a switchback.
2. Designing a switchback Rather than continue the ramp around to the west side of the pit, we will keep the ramp on the east wall. In order to do this we will need to insert a switchback. Window In on the north end of the pit as shown below.
Select the Design String item on the status toolbar and set the design string number to 99 as shown (alias SS).
String 99 is a temporary string number, which distinguishes the point or string from others used in the design. It will be used here to generate a point at a specific location, then a point from the pit outline will be snapped to it. From the Create menu, select Points, then By angle.
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Choose the inside point and outside points shown by the arrows for the backsight and foresight points respectively:
Complete the form as shown below to locate a new point for string 99, at an angle of 180 deg, and 20 metres from a setup point.
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From the edit menu, choose Snap point from the status toolbar, then Move point. Move the point shown to the new string 99 point. This will position it correctly in order to start the ramp again and continue the design.
From the Edit menu, select String, then Delete range to delete string number 99.
Turn Snap off from the status toolbar
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From the Edit menu, select Point, then insert point and move point functions to design the turnaround zone.
From the Pit design menu, select New ramp, and pick the two ramp entry points. In the example above, these points are #300 and #301. Complete this form as displayed below.
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If you want to change the direction of a ramp you need to use Ramp properties, select the string concerned (in this case, the outermost string (string #9)), and change Delete from N to Y in the displayed form. It is then a simple matter of redefining the new ramp. As mentioned earlier, you may need to check the geometry after each expand string or segment, and make any required corrections. This usually occurs when several points in one string or segment converge during the expand process, so that they either lie very close together in the subsequent string, or form a spike.
Each time a Segment is expanded to form the next crest or toe, Surpac Vision automatically checks and is often, but not always, able to correct invalid geometries. This sometimes involves deleting or moving offending points.
It is recommended that each time an expand function is used, the user checks the geometry to ensure that it is valid. The two areas which are particularly prone to errors are inflexion points on the outline or in the vicinity of the new Ramp.
From the Expand string menu, select By bench height, to proceed to the 930 elevation toe.
Note: When expanding a string or segment to a crest or toe, an error occasionally appears that reads as follows: SSI Warning: The `Ramp #1' ramp edge points have been moved or deleted. They must be re-selected to continue. This event may not occur in your design; however it may be worthwhile to understand how this type of problem can occur and be overcome. The reason for this event is that when pit outlines are generated, points are sometimes automatically removed or created to prevent spikes and/ or cross-overs. Occasionally, a ramp point is removed, invalidating the definition of that ramp. When this happens, the message above is reported. The report prompt will prompt you to re-define the ramp and temporary markers will guide you to the selection points. After re defining the ramp, the design process will continue.
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As you work with a design, it is good practice to investigate anything that may cause problems. Drawing the point numbers on the outermost outline can help identify where points are too close or too far apart. If they are too close delete excess points, or too far apart use edit insert point to add points. Refer to the example below, noting how the new toe is only shown as a guide at this stage: At the north end of the pit, the pit outline is close enough to the Whittle pit so we will not adjust the pit outline on this bench. After checking the outline proceed to the 940 elevation toe, Applying Expand string Bench Height followed by Expand string By berm width. Now save the design to file pitdes940.str. From the Block model menu, select Constraints, then Remove last graphical constraint. From the Block model menu, select Constraints, then New graphical constraint, to show block model between 950 and 940. The screen should look like the following image:
Extend the toe outline at the north end to capture the ore on this bench.
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Continue up another bench to the toe at 950. The screen should display the following image.
At this level we will design another switchback. Do this interactively, as before. Window In on the switchback area. From the Edit menu, select Point, then Move and Insert, to design a switchback similar to the one shown below.
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From the Pit design menu, select Ramp properties, and Delete the existing ramp. From the Pit design menu, select New ramp to define a new ramp with properties as before, except with an anti-clockwise direction.
Continue to the next toe at 960. Update the block model display. Your design should resemble the image shown below.
Continue to look closely at the outlines being created and modify where necessary. Remember the undo button if you make any mistakes.
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Continue using Expand string By bench height and Expand string By berm width for 2 more benches, until you reach the 980 elevation crest, as shown below.
To see the pit design without the Whittle blocks and geological model, simply invoke the Faces Off function under the Attributes menu. From the File menu, select Save, then string/DTM, to save the design as pit980.str.
Summary
This section took you through the second stage of the design of a simple pit. The following points were covered:
• Restarting a Pit design • Designing a switch back • Correcting geometry problems
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Pit Design to Surface
Overview
In this section we will continue moving up through the design and look at how Surpac Vision takes into account the topographic surface. This section of the manual will take you through the third stage of the design. We will finish the existing design taking into account the natural surface. This section contains a broad overview of the functionality of the following:
• Pit design to a surface • Pit expansion constraints
We will continue with the design started in the previous section. The new Pit tools contain a number of options for handling the interaction with the land surface, such as automatically terminating the design along the sides as they meet the land surface and conditional creation of berms as they near the land surface. For example, you can nominate for a berm to be generated only if the distance to the surface is less than, say, five metres. We will now expand the pit design up to, but not past, a limiting surface. Apply Faces Off and Edges Off. This turns the block faces and edges off on the block model so the model is no longer visible.
When studying the geometry following an Expand Segment, it may be easier to see the points of interest by erasing all the strings, then drawing the last outline. Make sure you do an ID point before erasing the strings to get the string number you wish to draw. If you need more
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information, draw the point numbers and Window In closely to check for points that lie suspiciously close together. From the Pit design menu, select Load DTM surface, and complete the form as shown below.
This loads the topography DTM into memory. From the Pit design menu, select Display DTM surface offsets. Select the outermost pit segment. The vertical offset to surface for each point on the outline will be posted to the left of the point, as shown below.
From the Display menu, select Hide strings, then In a layer, and choose the main graphic layer to hide the strings so the offsets are readable.
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As you can see we are approximately 17 metres below the topography at the closest point, so we should put a berm at this level all the way around the pit and then proceed up to the 990 crest. From the Pit design menu, select Hide DTM surface offsets. From the Display menu, select Strings, As lines. From the Expand string menu, select By berm width. Complete the form as before for a 5 metre berm all around the pit. From the Expand string menu, select By bench Height and continue to the 990 level. From the Pit design menu, select Display DTM surface offsets and select the outermost pit outline, the 990 crest.
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From the Display menu, select Hide strings. The offsets to topography should be as shown below.
On the east side of our pit we are now within 7 metres of topography. Before we put in another 5 metre berm all around our pit we must ask if it is sensible to design a berm if we were within a couple of metres from surface. When mining this pit, there is no way that a 2 metre bench would be mined and then a safety berm built. Therefore, there is some distance to surface within which, no berm should be designed. For this exercise, we will assume that this distance is 5 metres. Another way of looking at it is that our uppermost bench can be up to 15 metres high without a safety berm. From the Pit design menu, select Hide DTM surface offsets. From the Display menu, select Strings, As lines.
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From the Expand string menu, select By berm width. Complete the form as shown below.
Entering this berm creation method specifies: `only create a berm where the difference in elevation up to the DTM is greater or equal to 5 metres.' In our case, a 5 metre berm is created all around our pit (as shown below) because there was nowhere where we were within 5 metres of the topography.
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From the previous Display DTM surface offsets function we know that we are less than 10 metres vertically from the topography on the east side of our pit. Therefore we no longer want to use the Expand string By bench height function to design a full 10 metre bench. Instead we will use the Expand string to DTM function which allows us to expand up to the intersection of the topography. However, expanding up to the topography alone would not give us the desired result, as we would have a 30 metre bench with no safety berms on the west side of the pit. Fortunately, the Expand string to DTM function allows you the flexibility of expanding to a DTM while not exceeding a specified maximum bench height, which is exactly what we want to do here. From the Expand string menu, select To DTM surface. Complete the form as shown below.
The bench is created. At the east side of the pit it is less than the full 10 metres. The % of height to DTM option in the above form defaults to 100 which means that each point on the selected string achieves the elevation or the DTM surface. If you want the new string to only progress a fraction of the distance to the DTM surface then enter the appropriate percentage, for example 50 to progress half of the distance to the DTM, 25 to progress one quarter of the distance to the DTM, etc. From the Pit design menu, select Display DTM surface offsets. From the Display menu, select Hide strings.
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The screen should look as shown below. As you can see we are at the surface on the east side of the pit, shown by the 0 vertical offset to surface.
From the Display menu, select Strings, As lines. Because the ramp is at the surface we should stop the ramp. From the Pit design menu, select Ramp properties. Select the outermost pit segment (selecting this on the west side of the pit) and on the displayed form, change the Delete field from N to Y. From the Expand string menu, select By berm width, and Apply the form with the defaults. These are our previously entered values. As you can see from below, we only have a berm created where we are greater than 5 metres from surface, i.e. on the west side of the pit. We will now take a closer look at the Expand Segment By Berm Width function. This function allows a berm to be created if it satisfies certain conditions and to be omitted if the conditions are not satisfied. In the above example the berm satisfies the criteria to the west, but not to the east. Hence, the berm is created only on the west.
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The Berm creation method field on the input form has a number of options as shown:
You will notice that there are several choices. There are several examples of the use of the function which should enable you to select the correct option for the situation you are dealing with:
Always
This option creates the berm around the entire perimeter of the previous outline.
Delta z up to DTM >= This is used when building a pit from the base, and expanding the design upwards. If you use a value of 5 metres for the `delta z limit' field then a berm will be created whenever the distance from the last crest up to the DTM is greater than or equal to 5 metres.
Delta z up to DTM <= This is also used when building a pit from the base up. If you use a value of 5 metres for the `delta z limit' field then a berm will be created whenever the distance from the last crest up to the DTM is less than or equal to 5 metres.
Delta z down to DTM >= This is used when building a Dump from the top, and expanding the design downwards. If you use a value of 5 metres for the `delta z limit' field then a berm will be created whenever the distance from the last crest down to the DTM is greater than or equal to 5 metres.
Delta z up to elevation >= Options that are conditional on a distance to an elevation work in a similar way. These are useful when a crest has been built to a DTM or coal seam surface, and therefore has a variable elevation. You may then wish to have a berm only if the crest or toe (depending whether you are going up or down) is greater than a given distance to a nominated elevation rather than DTM.
Delta z to DTM (ie. does not specify whether we are expecting to travel up or down to the surface). This is useful when using the Pit tools for designing a road where a string defines the road surface and the Pit tools are used to create the batter angles which may go up or down depending on whether the road is higher or lower than the DTM surface.
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You may find it useful to split the screen into three zones so that you can view a close-up of the north and south ends of the Pit. At the top left of the viewport, select the solid filled arrow that point’s right to split the screen vertically. Next, on the right hand viewport, click the solid filled triangle that points downwards to split it horizontally. Now use the viewing tools to arrange the views as shown.
If you wish to view different data in each viewport, simply open the data into a new layer. You can then set the desired layers to not visible for each viewport since the layer settings for each viewport are independent. Save the pit design string file for backup purposes. From the Expand segment menu, select To DTM surface. Ensure you select the segment on the west side of the pit, so you are sure that you are selecting the outermost segment of the pit. It does not matter which viewport you use, provided you can see the zone of the pit where a berm was created in the last design step. The default form entries will be our last entered values. Apply this form and a bench will be created on the west side of the pit. Careful selection of the segment is required since you now have two lines on the east side. If a bench or berm is not created along some part of the edge, the string is still created there, but is coincident with the previous outline. For the above example you should select the line on the west side of the pit, since that line is unique, and there is no danger that the wrong segment will be selected.
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From the Pit design menu, select Display DTM surface offsets.
We still have 18 vertical metres at the southwest of the pit until we reach the surface. From the Expand string menu, select By berm width, and accept the previous entries. From the Expand string menu, select To DTM surface, accepting the previous entries. From the Pit design menu, select Display DTM surface offsets. They should resemble the following:
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We now have a maximum of 9.998 metres to surface. The next expansion to DTM will take us to the surface.
From the Expand string menu, select To DTM surface, and change the maximum bench height back to 9999 so the 10 metre bench is no longer a limiting factor. The segment will be expanded to the surface topography DTM. From the Pit design menu, select Display DTM surface offsets, to ensure that you are at topography all around the pit. The screen should look approximately as shown below, with the offsets all being equal to zero.
The pit design is now complete. Save the file to pitdesign2.str. Using the interactive 3D viewing tools, study the pit in 3-D.
Summary
This section took you through the third stage of the design of a pit. The following points were covered:
• Pit design to a surface • Pit expansion constraints
If you are unsure of any of these points please go back over this section before continuing. In the next section we will create a DTM of our design.
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Pit Design to Surface Model
Overview
Having completed the design phase we will go through the steps to prepare and create a 3D surface model. In this section we will use the Clean functions to check our design before creating a Digital Terrain Model (DTM). The DTM can then be used for presentation and generating reports. The points that will be covered in this section include:
• String file clean functions • Creating a DTM
1. String file clean functions We now wish to clean up the string file of the pit to enable a DTM to be created. The following image shows a view of the design so far.
This pit design is ready to plot, however to help visualize the design and calculate volumes we need to create a DTM.
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From the Surfaces menu, select DTM File functions, then Create DTM from string file. Complete the form as shown below.
Depending on how the design has gone you may get an error message and file stating: “This process detected xx breakline intersections in the design”. Breakline strings are those strings which represent physical features that you can see in the real world, e.g. crest of a pit. If a string file has been formed correctly, then no breakline strings will cross over other breakline strings, unless the two strings cross at a common point. A DTM cannot be formed with breakline intersections, so they must be fixed. This can be done either interactively in Graphics using the editing tools, or by using some of the String Tool functions.
The intersecting string numbers and intersection coordinates are listed in the message window and note file. They can also be highlighted graphically. This is done using the Clean layer function under the Edit Layers menu.
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Open the pit design into the graphic workspace. From the Edit menu, select Layer, and then Clean. Complete the form as shown below.
All breakline intersections will be highlighted with a red triangle. In this case, all intersections occur at the perimeter of the pit.
This can happen due to the technique used for the pit design. Once the design daylights in one portion of the pit, such as the east side, further segments are still created here when using the expand segment functions. Because no expansion takes place in this part of the pit, new segments are created directly over the top of existing segments. This can sometimes result in breaklines crossing each other.
The reason for the breakline intersections is that the points in the segments that overlie each other do not quite match. Windowing in on these areas will often show the image below.
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At each of these points there may be many coincident segments, therefore, manually trying to fix the intersections using the graphics editing tools would be difficult. From the File tools menu, select Check for common points. This function adjusts any points which are close (based on user inputs) to any other points so that they have exactly the same coordinates. The string range here is the strings numbers involved in the breakline intersections as displayed when creating the DTM. Note the output file name is different so that if things go wrong we have not destroyed our original file.
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Open the new file. From the Edit menu, select Layer, and then Clean. Complete the form as shown below to check for any breaklines which may have escaped the cleanup process.
If you continue to have one or two intersections, you may wish to clean them manually using the string edit tools in graphics. Using Snap on Mode can help in this process. When you are sure you have no intersections, save your file as pitdesign2.str again and clear Graphics. From the Surfaces menu, select DTM File functions, then Create DTM from string file, fill in the new file name and select Apply. After the DTM has been created, open the DTM file by specifying 'd' for file type on the open file form. Select the following: hide on, edges off, lights on, enter 1 1 1 and the colour yellow. This will display a 3D image of your pit design.
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You may also wish to experiment with drawing coloured banding. From the Display menu, select DTM with colour banding, and enter the following details to distinguish the benches by colour. From the Display menu, select Colour banding options, and then Smooth colouring to give sharp boundaries to the colour bands.
Summary
That completes the design process with a selection of the available design options. Please refer to the Online Help Manual for more detailed information.
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2. Grade and Tonnage Calculations
Overview
This section takes you through the calculation of in-pit grades and tonnages, breaking them into bench and grade ranges using Surpac's highly interactive Block Model reporting tools. Having designed the Pit, we wish to generate a grade and tonnage report. It is very simple to generate this report when using the Pit Tools combined with the Block Modelling tools. The tools also allow for a great deal of flexibility in the generation of the report. In the following exercise we will generate an in-pit grade and tonnage report, generated on a bench by bench basis, with volumes and tonnages reported for different grade ranges. This involves nominating which benches we wish to include in the report, then simply applying the appropriate block model constraint.
Choose the Block model pitdes.mdl by clicking and dragging from the navigator into the graphic workspace.
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From the Block model menu, select Block model, then Report. Enter the parameters as shown below and choose Apply.
It is important that we apply constraints as this is what allows us to report on only the blocks inside the pit.
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Enter the constraints as shown below and choose Apply.
Saving the constraint to pit_ore is not mandatory but will allow for more efficient application of this constraint in the future. A constraint file can be considered as an index of the blocks satisfying that constraint. Therefore, if another volume report was to be run on the in-pit reserves for different grade ranges, (for example) the constraint file could be specified rather than the two surfaces. This would result in quicker processing because the spatial constraints would not need to be re-calculated. The message window reports: Grand Total Volume = 555198 TONNES = 1490231 gold = 4.154 silver = 28.299 Read 2.40.not for details. Your numbers will probably not be exactly the same, but should be close to those given above. View in_pit_reserve_report.not in a text editor. It will contain the detailed volume, tonnage and grade report for the in-pit reserves broken down first by bench, and then within each bench by grade range. Sub-totals will be reported for each bench. To report tons of ore and tons of waste on each bench, for the gold range enter -1000;x;9999, where x is the cut-off grade. Blocks outside of the mineralized zone have had no grade assigned to them and therefore still have their gold 'grade' at the background value, set when the attribute was created in the model. In our model, the background values of gold and silver are -999. Therefore the first number in the gold range must be -1000 or less, so that the blocks which have had no grade assigned to them will be reported.
Summary
If you want to see all of the steps performed in this chapter, either run or edit:
07_grade_and_tonnage_calculations.tcl Note: You will need to Apply the forms that are presented.
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3. Creating a Map of a Pit Design
Overview
In this section you will create the map of the Pit Design and natural surface. The map will show the pit crests and toes, in different line styles, as well as labelled topography contours outside the pit. Now that the Pit design is complete one of the next steps is to produce a plot. In this section you will create the map shown below as well as gaining a broad overview of the mapping functions: This manual is intended to focus on the Pit Design tools, rather than Plotting. All user inputs required to create this plot will be shown, however detailed explanations will not be given here A general introduction to plotting is contained in the Principles of Surpac Vision Applications Manual.
• Merging and preparing data • Creating additional entities • Creating a map definition • Processing and reviewing the plot
Before plotting the pit and topography you will merge the pit design and the topography into one string file.
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Because of the technique used for the pit design, whereby the pit was designed up to the topography and not above it, the pit design is ready to plot without further modification. However, the topography contours presently exist over the top of the pit design, and must be 'clipped' with the uppermost crest in order that only the topography contours outside of the pit may be plotted.
The first step is to extract the topography contours outside of the pit. The Apply Boundary function is used for this.
Reset graphics to clear any data from the screen. From the File tools menu, select Apply boundary string. Enter the parameters as shown below. Note that your crest string may be different so check it and use the one that is applicable
Before we append these files into a single Graphics layer to create one file containing the pit and topography, we must be conscious of the string numbers which the resulting file will contain. If the data is merged into one file, then the string numbers must be different for data that we wish to plot differently. We will want to plot the contours differently to the pit design, but presently they both have string numbers incrementing from 1. Contour data is much easier to manage if the string numbers are related to or, if the data allows, are equal to the contour values. Because our topography contours are integer values between 1 and 32,000, we are able to assign the string numbers to the contour values (string numbers are limited to the range 1 to 32,000). This will make it easier to manage this data within the string file, especially when wishing to plot the contours, and the index contours with a different line style.
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From the File tools menu, select String summary, to check what the range of Z values are.
View the temp_topo1.not file. You will see that the string numbers range from 1 to 20 and elevations from 990 to 1085 in 5 metre intervals. Open the file temp_topo1.str into graphics. From the Edit menu, select String, then Renumber range. Complete the form as follows:
The String range from and String range to fields in the above form need to each have the same number of values so they can be matched. Otherwise the form will ask you to correct the entries.
Save the file to temp_topo1.str. Open temp_topo1.str and pitdesign2.str and append into same layer. Save this data to pit_and_topo2.str. You are now ready to set up the plot entities and map.
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4. Plotting From the Plotting menu, select Entity, then New, and complete the form as follows:
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From the Plotting menu select Entity, then New. Complete the form as follows:
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From the Plotting menu select Entity, then New. Complete the form as follows:
Ensure that Text Angle Type is set to RELATIVE (see immediately below the Text Angle field in the string operation) so that the contour labels are plotted parallel to the contours. In addition to the string operation, the entity should also contain a line operation specifying the use of a solid line (as in the crest entity).
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Next we will create a Map Definition. From the Plotting menu select Map, then New. Complete the form as follows:
After the map definition has been created, from the Plotting menu select Process, then Map. Complete the Plot Presentation Parameters form as shown below:
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Enter suitable input for the title lines within the title block and choose Apply.
Set the lower left corner of the map at the coordinates shown below:
Choose a grid interval of 100 and a grid type of border ticks to create ticks at the edge of the page.
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Open the plot file into Plot Preview. It should resemble the following image:
This completes the plotting exercise.
Summary
Plotting in Surpac is very flexible. Once the required entities and maps are set up, Surpac provides a very efficient and powerful plotting tool.
If you are unclear on any of the above information you may want to review this section before continuing.
If you want to see all of the steps performed in this chapter, either run or edit:
08_plotting.tcl Note: You will need to Apply the forms which are presented.
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Visualisation
Overview
This section provides an overview of visualisation. It shows a procedure to simulate driving down the ramp into pit. The exercise covers some of the more commonly used Surpac functions such as Drape strings over DTM and String maths. Both are important Surpac functions which have not been used elsewhere in this manual. We wish to generate a string which begins at the top of the dump, crosses the topo surface and then follows the ramp down to the bottom of the pit. We will then drive along the string seeing the surfaces as they would appear to a dump truck negotiating a ramp.
The first step is to use the combined topo, pit and dump surface to digitise and then fit a string along the desired path.
Open Pit_Dump_and_topo2.dtm, naming the layer Pit. If this DTM does not already exist, create it using strings as breaklines. The file Pit_Dump_and_topo2.str was created by combining the topographic surface, pit design surface and dump design surface from the preceding plotting and dump design exercises. The image below should be displayed on your screen.
From the Create menu select Digitise, then Properties, enter the parameters as shown below and choose Apply.
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The elevation is set at 2000m so that the digitised line is visible above the topo surface, which has an elevation of approximately1020m. Use of string number 9999, which doesn't already exist in the layer, will allow us to easily save the string by itself to a file. From the Create menu, select Digitise, then New point at mouse location, to design a string across the land surface as shown, starting on top of the Dump.
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Save the line to a file called drive1.str. On the following form, don't forget to specify the string number (9999) that you used for the digitised string.
The next step is to drape the drive1.str string over the topographic surface to assign the topo elevations to the drive string. From the Surfaces menu, select Drape string over DTM. Apply the following form, accepting the defaults which specify that the elevation of string file will be modified to match the elevation of DTM.
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Next we will add 5 metres to the drive1.str, so that it is slightly above the topographic surface. From the File menu, select Reset graphics. From the File tools menu, select String maths, and enter the parameters as shown below and choose Apply.
Open the resulting file in graphics. We could use the file Pit_Dump_and_topo2.dtm for our visualisation, however having the topo, pit and dump combined into a single DTM would prevent our ability to colour each feature differently. Therefore we will trim the excess triangles from the edges of the original Pit, Dump and topo files and then use those for the visualisation.
Ensure you have DTM's of the following files which were created in previous exercises.
• PITDESIGN1.DTM • DUMPDESIGN1.DTM • TOP1.DTM
If you are missing any then create the DTMs using breaklines.
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Open the pitdesign1.dtm file, then draw the strings without labels. Note the excess triangles outside of the actual design strings indicated by the four arrows:
From the Surfaces menu, select DTM file functions, then Clip DTM by boundary string, to trim off those excess triangles.
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Clip the DTM , Note: You need to determine whether to clip `Inside or Outside'. This depends upon what data you want to keep. ' If you want the triangles inside the boundary string' then select `I' for inside. Conversely, if you wish to keep the triangles outside the boundary string, then select `O' for outside. In our case select Inside. Compare the pit_clip2.dtm with pitdesign2.dtm.
Repeat the process for dumpdesign1.dtm, creating the file dump_clip1.dtm. View the file first and use IP (identify point) or select Inquire then Point Properties to check the string number of the outside string which will become the boundary string. Use the same method to trim a hole in the top1.dtm, where the pit is to be excavated. The entries for the DTM Clip form are as shown below:
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Repeat the clipping procedure to remove the redundant triangles from the edges of the dumpdesign1.dtm file:
We are now ready to open each of the clipped DTM surfaces, colour them and then drive around the site. At this point, it is optional to begin recording a macro, so that you can show your design process to others on site. From the main Toolbar, Press the Macro Recorder button to begin recording the macro, giving it a suitable name.
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Open the file top_clip1.dtm by dragging it into the Graphics area. Display the DTM.
Open the file pit_clip2.dtm into a new layer. To generate a new layer simply type a new layer name into the layer field on the Open File form. Rescale the view. Display the DTM again, entering the parameters as shown below and choose Apply.
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You should be viewing the following:
Be sure to open each of these files to a new layer. Otherwise when you draw a shell of the surface, it will also re-colour the other surfaces in the same layer. Open the file dump_clip1.dtm to a new graphics layer, without re-scaling. Display DTM of the Dump:
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Your screen should display the following image:
Open the file drive1.str to a new layer called Drive, with rescaling.
Hide the string.
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Display a single marker at the start of the string:
A single marker should be displayed near the top of the screen. Ensure that you can see the marker. From the main menu, select View, Layer, Properties and make all the layers except the Drive layer, not selectable:
From the View menu, select Data view options, then View along a string.
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Pick the marker from the Drive string and sit back and enjoy the ride. Now press the macro recording button to stop recording the macro.
Summary
This concludes the training on the Surpac Vision Pit design module. In this manual we have tried to cover the main areas of pit tools in a basic pit design. The functionality is more extensive than shown here and we recommend you refer to the Online Reference Manual for more details on the extent of some functions.
The Pit Tools provide a tremendous amount of flexibility for designing Pits and Dumps. We are sure that your appreciation of the tools will grow as you are faced with more challenging designs.
Please feel free to provide feedback to SSI on the Pit Tools manual. As with much of Surpac's development, enhancements to our products are driven, to a large extent, by the input from our users.
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Waste Dump Design Overview
The Pit design tools provide a high level of flexibility when performing dump designs. This section will show you how to use the Pit Tools to create a Dump Design and a DTM of that design. We will then generate a Volume report, and a Bench Volume report of material that can be stored on each bench. Requirements The software tools used for dump design are the same as those used for the proceeding Pit Design exercise. Many concepts detailed in the Pit Design exercise are not repeated in this exercise. For this reason, the Pit Design exercise must be completed before beginning the Dump Design exercise. We will perform the dump design on the combined surface of the topography and the pit design. These files were combined in the previous section where you created a plot of the design. A key objective of this exercise is to show you how to set up an all cut ramp. Open pit_and_topo2.str. Your screen should display the following image:
Open the file dcl1.str onto a layer called dump ramp cl, leaving Rescale set to Y.
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The image shown below will be displayed.
It is not mandatory that you call the layer name dump ramp cl, as layer names are only temporary and only exist for each Graphics working session. Layer names are not saved with the string files. A layer name should describe the data on that layer. If you are unsure what layer name to specify when you are opening a file, simply give the layer the same name as the file location name. This is made easy by using copy (Ctrl-C) and paste (Ctrl-V) on text between fields on a form.
Open the dtop1045.str into a layer dump top. Rescale the screen using a combination of window, zoom and pan tools until the screen looks approximately like the image below:
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We are now ready to start the dump design. The top of the dump is approximately 50 metres above the topography, at an elevation of 1045 metres. The elevation and gradient of the centre line is irrelevant. The gradient will be set during the dump design process. From the Pit design menu, choose Select slope method. In the Define Slope Method form, choose Design slope. From the Pit design menu, choose Set slope gradient. Set the design gradient to 38 degrees and choose Apply. The new design gradient will be shown in the status toolbar at the top of the screen.
From the Display menu, select Point, then Markers. From the Pit design menu, select New ramp, then select two points on the dump top, one on either side of the ramp centre line.
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Enter the parameters as shown below and choose Apply.
After applying the above form, you will be prompted to select the ramp centre line. Select the ramp centre line anywhere on the centre line where there are no other strings which you may accidentally snap to. This is achieved by selecting the line somewhere along the centre of the segment, not at the ends. After selecting the ramp centre line, the dump top outline is actually modified very slightly as shown in the next image. This change is made by the software to resolve geometry problems at the start of the ramp.
We will only have one safety berm at 1025 metres in this dump. We have a choice of either using Bench Height and designing a 20 metre bench or using To Elevation and specifying elevation.
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Using To Elevation is simpler as it does not require us to do the mathematics ourselves and also shows a function not used in the previous pit design exercise. From the Expand string menu, select To elevation, then click on the dump outline. Enter the parameters as shown below and choose Apply.
The projection of the selected string towards the target elevation may result in a design which is unacceptable for the type of mining equipment which will be used. By entering the Maximum bench height the design may be restricted to ensure that limits are not exceeded. If a bench height limit has no value in your design you can enter a large value such as 9999 or as shown on the previous form if expanding down the value needs to be below the present design elevation thus -999.
The screen will be updated, as shown below.
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We will now create a 10 metre berm at this elevation. From the Expand segment menu, select By berm width, then enter the parameters as shown below and choose Apply:
Now we will project the dump outline to the DTM of the topographic surface. Choose Load a DTM surface and load top1, leaving the display DTM at N.
From the Expand segment menu, select To DTM surface, and enter the parameters as shown below.
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It is important to change the limiting elevation from 9999 to 0 so that a limiting elevation is not used.
The image shown below will be displayed
Show the DTM offsets to see that the base of the Dump has been extended to match the DTM surface.
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Save the design to a file called dumpdesign1.str. Create a DTM of dumpdesign1.str using breaklines. Next we wish to clip a hole in the topo surface around the Dump design. For a boundary string we will use the Dump design string that lies on the topo surface (string #4). We will then append the clipped topo string file and dump design strings, and create a DTM of the surface. We will use the previously created topo surface which has already been combined with the Pit design strings. The two files to combine are pit_and_topo2.str and dumpdesign1.str Choose Reset graphics. Open pit_and_topo2.str.
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From the File tools menu, select Apply boundary string and enter the parameters as shown below.
Open dumpdesign1.str to the current layer using the replace option. Open temp10.str, appending it to the current layer.
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Create a DTM of pit_dump_and_topo2.str. Open pit_dump_and_topo2.dtm onto the same layer as the string file, replacing the string file. When opening a DTM onto the same layer where the DTM's string file is located, it is important to Replace the string file, and not append the DTM to the string file. When you open a DTM into Graphics, the string data comes in as well. The string data is not initially drawn but it comes in with the DTM. Without the string file, the DTM file would be meaningless.
Note:
A common mistake made by users is that when they append the DTM into Graphics, they may edit the string file and then re-save it. This creates a duplicate copy of the strings in the file, which doubles the file size, as well as requiring the duplicate strings to be removed before further effective graphical editing can be performed on the file.
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1. Dump Volumes We will calculate the total volume of the dump using the DTM Volumes function. From the Volumes menu, select Net volume between DTMs .Enter the parameters as shown below and choose Apply.
Apply the following two forms, while leaving the Save the Modified DTM field at N. Do not cancel this form as you will cancel the volume calculation.
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The form below gives you the option of saving the DTM clipped within the boundary string. This is done for visualization purposes as this allows you to colour the dump differently to the surrounding topography.
Note:
As a general rule of thumb you should only use clipped DTMs for visualization, and not for other DTM functions. This is true even if the DTMs are created using the Clip DTM function under DTM Tools. Most DTM functions can be performed within boundary strings. Using the boundary string and performing the DTM function on the unclipped DTM is much safer than working with clipped DTMs. Upon applying the second Save A Modified Dtm form, the volume is calculated and written to a note file, a file with a .not extension. View this file in a text editor. It contains the total dump volume, in this case 1.91 million cubic metres.
2. Dump Volumes By Bench Now we wish to generate a bench volume report from our dump design. It also serves as a good check for volume. This report gives you the amount of material that can be placed on each bench. Reset graphics then open dumpdesign1.str. Zoom Out once. From the Create menu, select Section axis using mouse, and digitise an axis (holding the button down) approximately along the centre line of the ramp extending all the way through the dump.
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You should see an image similar to the following.
Upon releasing the mouse button a form will be displayed. Apply this form with the defaults.
In the above operation we are defining an axis line. You will use the line to cut perpendicular sections. The bench volume report works from the sections through the two surfaces.
Save the string file to the same file name. From the File menu, select Reset graphics. From the Surfaces menu, select DTM File functions, then Create sections from DTM. Enter the parameters as shown below and choose Apply.
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The second form that is displayed is the Define An Axis Line form. This form will display the default coordinates taken from our digitised axis line. Apply this form with the defaults.
After applying this form, the sections are cut and saved to the specified string file. In our case, the file is temp_dump_sections1.str. This form takes the defaults from the axis record, from the string file of the first DTM, therefore it was important that we specified our final_dump_design as the first DTM. From the Volumes menu, select By elevation from sections. Complete the form, as shown below.
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A note file is produced temp_dump_sections0.not. View this file in a text editor. It contains bench volumes as shown below.
Summary
The section on Dump design is now concluded. If you are unclear on any information contained in this section you may want to review it before continuing. Circular ramps can be added to the design using the procedures shown in the Pit Design exercise.
If you want to see all of the steps performed in this chapter, either run or edit:
09_waste_dump_design.tcl Note: You will need to Apply the forms which are presented.
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