grouting report.docx

NO. CONTENTS PAGE NO.

1 INTRODUCTION 1-2

2 LITERATURE REVIEW 3-5

3 METHOD PROCEDURES 6

4 DISCUSSION ON METHOD 7

5 CONCLUSION 8

6 REFERENCE 8

7 APPENDICES 9-10

A.INTRODUCTION

Soil Stabilization Method by Grouting 2014

1.1 What is Soil Stabilization Method?

Soil stabilization is a way of improving the, “weight bearing capabilities and performance of in-situ sub-soils, sands, and other waste materials. The prime objective of soil stabilization is to increase the strength or stability of soil and to reduce the construction cost by making best use of locally available materials. There are many techniques for soil stabilization, including compaction, dewatering and by adding material to the soil. This summary will focus on latest technology on geotechnic. Among other technique of stabilization techniques, the grouting is one of the methods in soil stabilization. It the most expensive methods where some kind of stabilizing agent inserted into the soil mass under pressure.

1.2 TYPES OF Soil Stabilization Method

COMPACTION PILE

BLASTING

PRE-COMPRESSION

STONE COLUMN

VIBROFLOATATION

GROUTING

ELECTRO OSMOSIS

THERMAL TREATMENT

1.3 What is grouting?

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Grouting/injection it a word form German means the placing of grout material under pressure into caves, joints and pores of the subsoil to seal or to stabilize it. Grouting is a process whereby fluid like material, either in suspension or in solution form are injected into subsurface soil or rock to achieve a decrease in permeability and compressibility.

1.4 Purpose of grouting:

Improve the poor soil with heavy loading condition. Fill up existing caves,joints and pores. Serves for sealing and for stabilizing rock and soil. To increase the shear strength. To decrease the compressibility. To decrease the permeability.

1.5 Why need grouting?

When the foundation has to be constructed below ground water table.

C When there is difficult to the foundation level (ex: city work, tunnel shafts,sewers, subway construction).

When the geometric dimensions of the foundations are complicated and involved many boundaries and contact zones.

When the adjacent structure require that the soil of the foundation strata should not be excavated.

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B.LITERATURE REVIEW

2.1 Categories of Grouting

A. Permeation/ Penetration grouting.B. Compaction grouting.C. Fracture Grouting.D. Mixing/ Jet Grouting.E. Fill Grouting.

A. Permeation / Penetration grouting.

Permeation Grouting is the most common and oldest form of soil grouting. The technique consists of drilling a hole in the soil, inserting an injection pipe into the ground and then filling joints or fractures in rock or pore spaces in soil with a grout without disturbing the formation.

Advantages

Controlled and accurate placement. Economical cost. Significant and predictable degrees of improvement. Non-vibratory. Limited workspace required.

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B. Compaction/injection grouting. Compaction grouting is to fill up an artificially created cave directly around the pipe where the grout material enters the surrounding soil. Compaction grouting is a repair mechanism that aims to increase the carrying capacity of the land. Due to the volume of soil pore structure decreases, the permeability will also be reduced. Even so, compaction grouting cannot fully prevent seepage. Compaction grouting can improve soil load for

compress.

Advantages

Pinpoint treatment, Speed of installation and effective in a variety of soil conditions. Can be performed in very tight access & low headroom condition. Non-hazardous, No waste spoil disposal, Non-destructive & adaptable to exiting foundations

and able to reach depths unattainable by other methods.

C. Fracture Grouting.

Fracture grouting, is also known as Compensation Grouting. It is the injection and hydro fracturing with grout slurry of the soil between the foundation to be controlled and the process causing the settlement. Grout slurry is forced into soil fractures, hence causing an expansion to take place counteracting the settlement that occurs or producing a controlled heave of the foundation. Multiple injections and multiple levels of fractures create a complementary reinforcement of the area.

Advantages

Elimination/Prevention of the settlement of buildings

Reduction or reversal of total settlement

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Prevention of the settlement of tunnels Reduction or reversal of differential settlement

D. Mixing/ Jet Grouting. Jet grouting is a construction process using a high kinetic energy jet of fluid to break up and loosen the ground, and mix it with a thin slurry. It is not truly grouting but rather a hydrodynamic mix-in-place technique producing a soil-cement material. Single, double and triple jets carry the necessary hydrodynamic energy to break up and mix the soil with the slurry. It is suitable for mass treatment, linear treatment and inclusions, in soils of good to poor grout

ability.Advantages

the very high speed jet loosens the soil the jetting fluid washes some of the soil to the surface the slurry adds a binder to the soil mix

E. Fill Grouting. Void Fill Grouting is typically called for when the roof of a void collapses, or a sink hole or depression forms producing deformation of the ground surface or when pre-construction site testing uncovers such potential defects. The gradual deterioration of the void, usually over a period of years, most often appears as cone shaped depression, or hole at the surface which can result

in damage to buildings, utilities and roadsAdvantages Void fill beneath or between concrete slabs Void fill beneath roadways and sideways Sealing pipe penetrations through concrete

structures

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C.METHODS PROCEDURE OF GROUT COMPACTION1.Bottom-up grouting

In this method the casing is driven to full depth & is withdrawn to a specified elevation, then grout is injected. This process continues upward to the surface of the material grouted. Fig (a)

2.Sealed-in sleeve pipe injection:

This method allows several injections at the same elevation. Injection is done by double packer, which is inserted in the sleeve pipe to the desired location. Although the method is more complicated than bottom up grouting & the initial cost during drilling & the selection of different grout viscosities as the grout take varies at different locations. Fig (b)

3.Simultaneous drilling & grouting:

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This method allows for injection during rotary drilling. At a pre-determined distance, drill rod is withdrawn and the grout is injected into the soil through a separate drill rod .The process continues from the top downward. However this method is only suitable for previous granular soil. Fig (c).

D.DISCUSSION ON METHOD

Dalesford lake development –Berwyn,Pennsylvania

A luxury, four unit town house structure founded on timber piles had exhibited structural distress related to sink hole activity.Surface investigation revealed 5-30ft of miscellaneous fill,including wood chips and building materials, overlaying clay soil. Beneath this,pinnacled karastic lime stone was encountered at depths ranging between 10 and 30ft.Grout pipes were installed at 68 interior, low head room locations and 90 exterior locations, to an average depth of 16 to 21ft. Compaction grouting was performed to stabilize the driven pile foundation, re-establish ground contact with the structure, and halt the soil piping that had resulted from sink hole activity.The work was successfully completed while the building remained occupied.

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E.CONCLUSION

> Many engineers still consider this grouting technique as a art rather than science.

> Its successful application requires great deal of experience, thorough knowledge of geological condition and awareness of equipment capabilities and limitations.

> The overall success of grouting technology is less than 50% of intended goals.

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F.REFERENCE

CHRISTIAN KUTZNER Consulting Geotechnical Engineer Honorary Professor, Technical University Darmstadt, Hofheim, Germany.

PRACTICAL HANKBOOK OF GROUTING Soil, Rock, and Structures (James Warner, P.E.)

CHEMICAL GROUTING AND SOIL STABILIZATION THIRD EDITION, REVISED AND EXPANDED (Reuben H. Karol).

G.APPENDIX

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grouting report.docx