PRESENTED BY:-

SHOAIB BASHIR WANI

18-CE-08

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Introduction History & Development of Grouting Grout & its types Desirable Characteristics of Grout Grouting Methods

I. Permeation Grouting

II. Displacement-Compaction Grouting

III. Displacement-Soil Fracture Grouting

IV. Jet or Replacement –Displacement Grouting

V. Rock Fissure Grouting

VI. Tube-a-Manchettes(TAM) Grouting

• Conclusion

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Injection of slurry or a liquid solution into a soil or

rock formation is termed as grouting. The injected

material is referred to as the grout. The process of

grouting was developed primarily as a technique

for making vertical seepage barriers beneath dams

and hydraulic structures by injecting cement slurry

into the void space of river bed material.

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Its traceable record can be as early as in the beginning of 1800s.

In 1802, the idea of improving the bearing capacity under a

sluice by the injection of self-hardening cementitious slurry was

first introduced.

In 1893, the first systematic grouting of rock in the USA as

performed at the New Croton Dam, in New York.

In 1960s, jet grouting technique was developed.

In 1977, first application of compaction grouting for controlling

ground movement during construction of the Bolton Hill Tunnel.

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Grout is a construction material used to embed rebars in masonry

walls, connect sections of pre-cast concrete, fill voids, and seal joints

(like those between tiles).

Grout is generally composed of a mixture of water, cement, sand,

often color tint, and sometimes fine gravel.

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Suspension :- Suspensions consist of small-sized

particles dispersed in a liquid medium. These include

cement grouts, that is, slurry of cement in water; soil-

cement grouts consisting of slurry of soil and cement in

water; and Bentonite grouts comprising slurry of

Bentonite in water.

Emulsion :- Emulsions consist of colloidal droplets of

liquid dispersed in a liquid medium; bituminous emulsion

fall in this category.

Solutions:- Solutions are liquid homogenous

molecular mixtures of two or more substances; chemical

grouts such as sodium silicate solutions and acrylic

resins are examples of solutions

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Properties of a grout are described in terms of five parameters:-

1. Groutability:- Expresses the ability of the grout to reach the

desired location in the soil, mass. To be able to do so the grout

should possess sufficiently high fluidity and the suspended

particles, if any, must be of a size that enables them to enter

the void spaces in the soil mass.

Groutability Ratio = D15 of soil / D85 of grout > 25

2. Stability:- Is the capacity of the grout to remain in a fluid state

and not segregate into its separate components. We need the

grout to be stable until it has reached its destination. Stability

of clay-cement grout is usually more than that of a cement

grout.

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3. Setting Time:- Is the time it takes before the grout sets into a cemented

mass or gel. Early setting can cause difficulty in grout reaching its

destination and late setting can result in the grout being washed away if

seepage is occurring through the soil. Additives are used to retard or

accelerate the setting time as required.

4. Permanence:- Indicates the resistance the grout possess against being

displaced from the soil voids with time. Cement grouts have greater

permanence than Bentonite grouts which can get washed away with time

by seepage of water through the grouted zone.

5. Toxicity:- Is the capacity of the grout to contaminate the ground water

coming in contact with it and of adversely affecting the health of workers

handling and injecting the grout into the soil.

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1. Permeation Grouting

2. Displacement-Compaction Grouting

3. Displacement-Soil Fracture Grouting

4. Jet or Replacement-Displacement Grouting

5. Rock-Fissure grouting

6. Tube-a-Manchettes(TAM) Grouting

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1. Permeation Grouting:- Permeation Grouting is defined as a

means of impregnating the voids within a soil or rock mass and

thereby displacing water and air from the voids and replacing it

with grout, without displacing the soil particles or widening the

existing fissures in the rock. It includes:-

• Injection of thin grouts into the soil.

• Once the soil cures, becomes a solid mass.

• Done usually using chemical grouts.

• Used for creating groundwater barriers or

preparing ground before tunneling.

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Application of Permeation Grouting:-

Permeation grouting is widely used for making vertical

seepage barriers beneath hydraulic structures. It is also

used for stabilization of soil around tunnels and shafts.

Other uses include stoppage of seepage through joints of

underground structures such as tunnel lining, basement

wall etc.

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(a) Grout curtain beneath dam

(b) Stabilization of crown of tunnel with chemical grout.

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Conceptual Diagram of Soil Solidification by

Permeation Grouting.

Grouting Pressure:- To enable rapid permeation of grout slurry into

the void space, a high injecting, that is, grouting pressure is desirable. It

must not, however, cause the soil mass to displace or to fracture. Hence

the grout pressure has to be limited to 25% of the effective overburden

pressure at the depth of grouting .

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At point A, the state of vertical effective stress is as follows:

Vertical effective stress =ơ/v = Ɣt h(major principal stress),

and for soils in the ‘at rest’ condition,

Horizontal effective stress =ơ/h =KOƔt h(minor principal stress)

=

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Grouting Plant for permeation grouting

using cement grout.

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2. Displacement-Compaction Grouting:- Compaction grouting is the

injection of a thick, low mobility grout that remains in a homogeneous

mass without entering soil pores. As the grout mass expands, the

surrounding soil is displaced and densified. A conceptual drawing of

compaction grouting is shown below:-

—When low-slump compaction grout is injected into granular

soils, grout bulbs are formed that displace and densify the

surrounding loose soils.

—Used to repair structures that have excessive settlement

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Application of Displacement-Compaction Grouting:-

Situations where displacement-compaction grouting is most applicable

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3. Displacement-Soil Fracture Grouting:- Soil fracture grouting

technique is a displacement grouting technique in which a learn

slurry of cement, soil and water is injected into the soil at high

pressure to fracture the soil and form root-like or thin lens shaped

zones of grout material in the soil mass. The grout material

spreads all around the grout hole causing densification of the soil

mass and an increase in its macroscopic strength.

Restoration of verticality of a tilted building.Displacement-Soil Fracture

Grouting

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4. Jet or Replacement-Displacement Grouting:-

In this technique, a special grout

pipe called the monitor having high-speed jets of water or grout is

used to erode and excavate the soil. Thereafter, as the monitor is

withdrawn, strong, impervious columns are produced by mixing

grout with the remaining soil.

Developed in Japan–Uses a special pipe with horizontal jets that

inject grout into the ground at high pressures.

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The sequence followed in jet grouting

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Application of Jet-Grouting:-

Grouted Columns:-

Jet grouted columns can be formed in almost all types of soil

ranging from sandy gravels to clays. Sands are best suited for

treatment yielding the largest diameter of columns. Presence of

inter particle attractive forces reduces the erosive efficiency of the

jets. Hence diameter of grouted columns are progressively smaller

in sandy silts, silts, clayey silts and clay. Gravels do not respond

well to jet grouting both because of loss of water or grout through

its voids and the difficulty in removing gravel particles.

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Applications of jet grouting

5. Rock Fissure Grouting:-Rock fissure grouting is the use of a hole drilled through the fissures

and joints of a rock mass to allow grout to be injected at close

centers vertically and re-injecting, if necessary.

Grouting Mechanism

There is only one grouting mechanism for rock grouting. The

following schematic diagrams show how the mechanism for grouting

in rock is. The grout is injected under pressure through the grout

hole drilled into the rock mass to be treated.

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Grouting in Progress Grouting Completed

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Application of Rock-Fissure Grouting:-

1. Sealing rock mass underneath and at ends of dams to prevent

seepage or leaking of the reservoirs.

2. Sealing rock mass above and underneath a rock tunnel to prevent

water seepage into the excavated tunnel.

3. Cementing fractured rock mass. Its main application is in the field of

water stopping, especially in tunnel excavation project.

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6. Tube-a-Manchettes(TAM) Grouting:-

Tube-à-Manchette (TAM) grouting is the use of sleeved

perforated pipes in grout holes, soils or completely decomposed

rock to allow grout to be injected at close centers vertically, and

re-injected, if necessary.

Grouting Mechanism:-

It is a grouting technique for grouting in soil formation only, with

partial or complete displacement of in-filling ground water.

Schematic Diagram of the

Impregnation Mechanism for

TAM Grouting

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Applications of Tube-a-Manchettes(TAM) Grouting:-

1. Sealing soil mass above and underneath a tunnel excavated in soil

under compressed air condition.

2. Sealing “windows” in cofferdams.

3. Consolidation of loose soil mass (cohesion less granular sand).

4. Sealing underlying soil of dams

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CONCLUSION

Grouting is a popular ground treatment technique, but not

so many engineers are familiar with it. And they often have

misconception about grouting. The project is to clarify on

one hand the basics of grouting, and then on the other

hand try to provide a full coverage of all types of grouting

mechanisms in practice. For each grouting mechanism, a

brief discussion is given to its design considerations,

construction and application. Finally, finite element

method is used to analyze and model grouting to confirm

the extent of grouting in terms of treatment zone and

degree of improvement of ground properties required.

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THANK YOU