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C3010 Highway Engineering UNIT2
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TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
i
TECHNIQUE IN PLANNING AND PRE-CONSTRUCTION OF ROADWORK
OBJECTIVES
General Objective
To understand the planning activities and all pre-construction works
Specific Objectives
At the end of the unit you should be able to :-
describe the planning objective. state the procedures to identify a new road. state the procedures for site investigation describe the method of site exploration. describe the survey works.
UNIT 2
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
TECHNIQUE IN PLANNING AND PRE-CONSTRUCTIONROADWORKS
2.0 TECHNIQUES IN PLANNING AND PRE-CONSTRUCTION ROADWORK.
A construction of a new road must under go an extensive planning,
accurate land surveying and economic planning.
2.0.1 Planning Requirements
A modern highway construction would include:-
1. A collection of a tabulated information on the existing transportation
facilities in the area.
2. The determination of the general inter-relation of all branches of the
transportation system and their effect on each other.
3. The determination of the adequacy or otherwise of the existing
facilities as per present needs and the improvement and extension
of these facilities for anticipated future needs for a certain period.
4. Methods of financing the projects and the duration of the
construction.
5. An estimation of construction and maintenance.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
Any highway planning study can be sub-divided into :-
1. Road inventory study.
2. Traffic studies.
3. Economic planning studies.
4. Financial planning studies.
2.0.2 Preparation and Planning Scheme of a New Road.
Planning expertise, evaluation on survey work, knowledge
on geology and experience on civil engineering area are essentially
needed in constructing of a new road. The traffic needs, the
purpose on planning at certain route and approximate cost thus
become very vital information to be considered before constructing
a new road.
The synopsis of procedures that is used for identifying,
planning and constructing a new road are listed in the following
page. However, not all new roads follow these procedures. Some of
the procedures are valid for certain terms and conditions only.
Below is set of procedure that is used for identifying,
planning and constructing a new road. The procedures are;
1. Identify the problem in traffic congestion, accident and
environment by making a research on transportation and
problematic areas.
2. Identify the maintenance and new construction work needed.
3. Identify the organization and Ministries that are responsible with
the construction work such as JKR, TNB etc.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
4. Collect the information for briefing.
5. Prepare the following plans: -
a. Topography plan.
b. Usage land plan.
c. Geology plan.
d. Agriculture area plan.
e. Domestic plan.
f. Traffic flow plan.
g. Town Consult planning document.
6. Draw a temporary layout sketch and include related
suggestion.
7. Get information on;
a. Junctions.
b. River and drainage.
c. Survey information.
d. The latest traffic data.
e. Ground Level.
8. Prepare a detailed layout with consideration to environmental
impact.
9. Make a valuation.
10. Choose the best road to be constructed. However, the
alternative road should be equally prepared in the planning.
11.Negotiate with other related group such as :-
a. Ministry of Science and Environment.
b. Ministry of Transportation.
c. Water Board, Forestry Department, Telecom Company
d. National Museum.
e. Railway Station.
f. Geology and Mineral Department.
12.Present a report on the entire technical problems.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
13.Analyze the problems faced by the public.
14.Prepare the preliminary report based on the above information
and submit it to the planning division.
15.Wait for the outcome or result.
a. If it is acceptable, draw a road design at 1 : 2500 scale
and proceed to the particular ministry.
b. If it is unacceptable, it needs to be revised thoroughly or
it will be cancelled.
16.Proceed with the following: -
a. Start planning the main task (the identified road).
b. Start planning the alternative roads.
c. Start purchasing the important materials.
17.Get the information from the public on the suggested road and
the other roads involved. Set a panel that consists of external
lawyers and other professionals to conduct a survey.
18.Submit the report to the respective Ministry and wait for the
approval.
19.Prepare the financial report based on the cost benefit analysis
to determine the advantages will bring to the public.
20.Advertise a tender notice and the selected contractor will then
need to prepare and submit the quotation of the contract plan
and document.
21.Accept the tender and start the construction work.
There are 3 stages in planning the construction of a new road :-
1. Stage 1 - Prepare a preliminary report.
2. Stage 2 - Submit the preliminary report.
3. Stage 3 - Finalize the report.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
2.0.3 Stage 1- Preparing a preliminary report.
In this stage, it includes all the preliminary reports and
information that are received during the ensuing stage (refer to
2.0.2, Procedure 14). They are: -
a. Traffic surveying work.
b. Evaluation on the information and planning. Consider
suggestion if there is another useful choice.
c. Design using 6 : 1 mile scale.
d. Budget of the construction and its advantages.
e. Identify the certain road.
f. Report on the alternative road, which includes the
topography, geology and traffic flow, soil consuming and
historical places.
g. Obtain cooperation from the related group such as town
council and state government.
h. If the project is over budgeted the ministry must be inform
and no further work shall be proceed.
2.0.4 Stage 2 - Submitting the preliminary report.
In the preliminary report, it explains about the proposal and its
alternatives of the identified project. It then is submitted to the
person in-charged to obtain permission. However, the following
questions need to be considered.
a. Are the suggestions fulfilled the planning needs at the
national level.
b. Are the advantages accepted?
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
c. Are the suggested solution accepted in term of
political or environmental aspect.
While the preliminary report is being studied further, other
experiments should be done such as:-
a. Further soil investigation.
b. The plan preparation on the new road and other related
roads. Report and work are to be prepared. It will only be
submitted if the preliminary report is accepted.
2.0.5 Stage 3 - Finalizing the Report
a. When the preliminary report is accepted, prepare the
road plan with 1:2500 scale.
b. When the final report is completed, submit it to the Head
Quarter for approval. Here, a right budget and
advantages of the project shall be included for approval
purposes.
c. After the costing and advantages valuation are done, this
final report will be submitted to the responsible person to
start off the construction work.
d. If there is no protest from the public or other parties in
fact, the tender will be offered and the selected
contractor. Then, all the construction works will start.
e. If there is a protest, a committee member will be set up
for further investigation.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
2.0.6 The content of the Preliminary Report
The preliminary report which includes the plan must contain the
following aspects:-
a. The existence situation which is on physical shape and
scheme objective of the existence road.
b. The traffic situation based on the latest data (not more
than 3 years). A report should include content the total of
traffic user.
c. The alternative roads, which include the costing,
advantages and the environmental impact.
d. Road classification identify the road classification that is
to be built; highway or ordinary road.
e. Negotiation on the report and the result.
f. Budget the total of roadwork cost, bridges work and
earthwork approximately 20% from the previous budget.
The cost report should comprise the following:
Roadwork:-
- Site clearing cost.
- Earthwork cost.
- Pavement construction and road shoulder work
cost.
- Road furniture work.
- Facilities service work.
- Contingency stretch cost.
g. Valuation is to see the economical aspect of the project.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
h. Enclosed plans plan with 6:1 mile scale is used for
new scheme. For the city or village area a bigger scale is
used. Plan must show the following:-
a. The plan of the approved alternative roads.
b. The type of junction and its location.
Avoid using the existence plan. Beside the, the activities
which would be included in the planning and pre-
construction road work are as follow:
1. Site investigation.
2. Survey works and setting out.
3. Site clearing and top soil deletions.
4. Earth works.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
TEST YOUR UNDERSTANDING BEFORE YOU CONTINUE WITH THE NEXT INPUT
1. State the planning objective of planning in executing a new road
development.
2. State four other activities in planning and pre-construction roadworks.
a.
b.
c.
d.
ACTIVITY 2 A
Question
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
1. The objective of planning is to provide a highway system which
would give maximum transportation facilities at a minimum cost.
2. The other activities in planning and pre-construction roadworks be
as follows :
1. Site investigation.
2. Survey works and setting out.
3. Site clearing and top soil deletions.
4. Earth works.
FEEDBACK ON ACTIVITY 2 A
Answer
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
2.1 SITE INVESTIGATION
Road structures are the structure which is supported by the ground.
The interaction between the structure and the soil beneath it is complex,
and therefore knowledge of the site and soil condition is important.
2.1.1 Procedures of the investigation
2.1.1.1 Compact sites
In the case of compact sites for road structure, the
investigation requires deep and closely speed borings. The
actual number and position of borings depend on the types
of structure and nature of sites. However, the number of
bore hole should be such as to given a clear picture of all
significant variations in the soil over the site, and the depth
of such bore hole should be such as to reach all strata
likely to influence the stability of the works.
2.1.1.2 Method of site exploration
When discussing the procedure of the investigation,
reference is made to borings as a means of the
investigation. This is perhaps it is the most common
method of site exploration, but certainly not the only one.
Considering new works, from the very small to the very
large contract, a general guide to exploration would be as
follows:
1. Small works- trial pits up to 3m deep.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
2. Medium to large scale works borings up to 30m
deep
3. Very large scale works a combination of deep
boring, pits and insitu examination from heading and
shafts.
It must be noted that the above is only guide: the
detailed methods of exploration would depend on the types
of the construction and the site involved.
a. Trial pits
This is the cheapest form of exploration in shallow
depth; above 3 m deep the cost increases rapidly compared
with boring. The main advantage is that soils and rocks can
be exposed and examined insitu. This method shows
changes in strata much more clearly than by boring. The pits
are dug out either by local labour or by a small tractor
mounted excavator. The plan size of a pits depends on
method of excavation, but approximately 1.2 x 1.2 m and
should be dug at distances 20m apart in either direction.
Problem occurs in water bearing soils, particularly
sands, and therefore the economies of shoring and pumping
pits may outweigh the savings gained against specialist
borings. In dry condition these pits are particularly valuable
since they allow hand cut sample to be taken, thereby
minimizing the disturbance of the sample and maximizing
the condition for accurate testing. Deeper trial pits maybe
used for investigation of rock fissures or to explore layer of
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
weak rock which cannot be removed intact in normal boring
operations. Such deep pits are costly to construct and would
be used only a large scale exploration. Trial pits are the best
method of exploring back filled areas and side overlain by
variable natural deposit.
b. Borings
All boring should be should be spaced sufficiently
closed together to prevent false deduction concerning the
uniformity of horizontal strata. The deeps of boring will be
determined by the type of loading involved but account must
be taken of any slope in the strata and variation in their
thickness. In particular, when boring through glacial
deposits, care must be exercised to insure that borders are
not mistaken for bedrock.
There are three main factors which govern the depth
of exploration:
1. The depth to which the soil is to be significantly stressed.
2. The depth to which weathering is likely to affect the soil.
3. The depth at which impermeable strata occur.
c. Wash Borings.
The soil is loosened and removes from the bore hole
by mean of a strong jet of water or drilling mud. The liquid is
jetted through a steel tube which is work up and down the
hole. The liquid disintegrates the soil and carries it up the
annular space between the tube and casing. Wash boring as
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
the advantage that the soil is not disturbed by blows of a tool
or shell, but it is limited to soil which do not contain boulders
or large gravels. Mud such as bentonite, allows boring to be
carried out without linings is non-cohesive soils. The soil in it
settled-out state can be dried and use for identification
purposes.
2.2 SURVEY WORK AND SETTING OUT
2.2.1 Preliminary Survey
The preliminary survey consist in running a accurate
traverse line, usually called the Base Line along the route already
recommended as a result of reconnaissance survey, in order to
obtain sufficient data for final location. Similar traverses may also
be run along the secondary routes, if any. The preliminary survey
shall help gather all the physical information which might affect the
final location of the highway. The traverse being an Open one,
adjustment cannot be made as in the case of closed traverse so
that in order to ensure some standard of accuracy, certain
precaution especially in the measurement of angels and chaining,
etc., are necessary.
After establishing the Base Line, important topographical
features may also be recorded. These features include swamps,
lakes and any other features which affect the final location and
design of the highway. All the information collected by preliminary
survey work is used in preparing a map, often called the basic plan
or Preliminary Survey Plan.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
The next step after recording all the available details on the
basic plan is to locate the center line of the proposed highway on it.
A number of trial lines are drawn on the plan, avoiding valuable
property, obstruction and difficult areas such as water-logged
areas, etc. Having thus selected the center-line on the plan, the
next step consist in transferring on to the field.
2.2.2 Setting Out
The first task is to establish a Base Line from which the
whole of the road can be set out. The position of this line must be
clearly marked on-site so that it can be re-established at any time.
Setting out was done by plotting the construction boundaries after
being referred from the previous survey on Preliminary Survey Plan
and Base Line. Wooden pact shall be placed at each reference
point and can be easily seen.
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
TEST YOUR UNDERSTANDING BEFORE YOU CONTINUE WITH THE NEXT INPUT
1. State the two methods that are used in soil exploration.
a. ________________________________
b. ________________________________
2. State the three main factors which govern the depth of exploration.
a. _________________________________
b. _________________________________
c. _________________________________
ACTIVITY 2 B
Question 1
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
1. a. Trial pits
b. Borings
2. There are three main factors which govern the depth of
exploration:
1. The depth to which the soil is to be significantly
stressed.
2. The depth to which weathering is likely to affect
the soil.
3. The depth at which impermeable strata occur.
FEEDBACK ON ACTIVITY 2 B
Answer
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
1. What are the procedures in identifying the construction of a new road.
2. Describe the following aspects: -
a. Preliminary Survey.
b. Setting Out
3. Describe the Trial Pits of soil exploration.
Question
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
The procedures to identify a new road include:-
2a. Preliminary Survey
The preliminary survey consist in running a accurate
traverse line, usually called the Base Line along the route already
recommended as a result of reconnaissance survey, in order to
obtain sufficient data for final location. Similar traverses may also
be run along the secondary routes, if any. The preliminary survey
shall help gather all the physical information which might affect the
final location of the highway. The traverse being an Open one,
adjustment cannot be made as in the case of closed traverse so
that in order to ensure some standard of accuracy, certain
precaution especially in the measurement of angels and chaining,
etc., are necessary.
After establishing the Base Line, important topographical
features may also be recorded. These features include swamps,
lakes and any other features which affect the final location and
design of the highway. All the information collected by preliminary
Answer
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
survey work is used in preparing a map, often called the basic plan
or Preliminary Survey Plan.
The next step after recording all the available details on the
basic plan is to locate the center line of the proposed highway on it.
A number of trial lines are drawn on the plan, avoiding valuable
property, obstruction and difficult areas such as water-logged
areas, etc. Having thus selected the center-line on the plan, the
next step consist in transferring on to the field.
2b. Setting Out
The first task is to establish a Base Line from which the
whole of the road can be set out. The position of this line must be
clearly marked on-site so that it can be re-established at any time.
Setting out was done by plotting the construction boundaries after
being referred from the previous survey on Preliminary Survey Plan
and Base Line. Wooden pact shall be placed at each reference
point and can be easily seen.
.
3. Trial pits
This is the cheapest form of exploration in shallow depth;
above 3 m deep the cost increases rapidly compared with boring.
The main advantage is that soils and rocks can be exposed and
examined insitu. This method shows changes in strata much more
clearly than by boring. The pits are dug out either by local labour or
by a small tractor mounted excavator. The plan size of a pits
depends on method of excavation, but approximately 1.2 x 1.2 m
and should be dug at distances 20m apart in either direction. Trial
TECHNIQE IN PLANNING AND PRE-CONSTRUCTION OF ROAD WORKHighway Engineering C3010 / UNIT2
pits are the best method of exploring back filled areas and side
overlain by variable natural deposit.