Remedial Measures A Foundation by Various Methods OF Grouting

1. Dept. of MBA, Sanjivani COE, Kopargaon 1
Advanced Engineering Geology With Rock
Mechanics (B.E. Elective–I )
5.8 Remedial Measures at foundation
by various methods of Grouting
Sanjivani College of Engineering, Kopargaon
Civil Engineering Department .
Presented By:
Dr. A.V. Deshpande
Ph. D (Geology), M.Tech (Env.Engg.)
Asst.Professor Civil Engg.Dept.
www.sanjivani.org.in

2. Advanced engineering Geology With Rock mechanics Dr AVD
What is grouting
Grouting involves injection of an aquous
suspension of solids ( Cement- based) in
the form of Slurry under pressure in to
the ground through drill hole or pipes to
seal all weak zones in the rock
formation.
The injected grout hardens with time.
Grouting is undertaken to:
 Improve Strength & Bearing Capacity
of the formation.
 Block seepage by reducing the
permeability of rock & Soil
formation.
 completely fill underround openings
fill Shear zones with crushed material
as a single solid entity.
 Raise & re-level structures &
foundation elements
 Augument pile capacity& pile repair
Grouting Process

3. Types of Grouts
Advanced engineering Geology With Rock mechanics Dr AVD
 Suspension Grout
 Portland Cement in the form of Slurry
Grout material is in the form of suspension.
 higher Water to Cement ratio is adopted
to facilitate smooth injectionin weak zones.
 Solution Grout
 Non-particulate grouts.material present
as a solution ,consist of two liqids which form
in to gel on mixing & hardens with time.
Setting varies with the type of material used.
Ex: Silicon Gel is prepared using Sodium Silicate Grouting Process
& Calcium Chloride.
 Solution grouts employed in two ways;
 One Shot grout: mix prepared initially & used as a grout.
 Two Shot grout: two chemicals injected successively in to hole to react &. form gel

4. Organic resins including epoxy - resins
Advanced engineering Geology With Rock Mechanics Dr AVD
 Most of the grouts are air-entrained.
 Foam gels are also employed in selected
cases.
 Foam grouts being of gaseous emulsion of
an ordinary grout involves lesser quantity
of grout material.suitable foaming agent is
added to crate foam.
 Choice of grouts depends on the nature of
materials to be grouted. Epoxy - resins grout

5. Advanced engineering Geology With Rock Mechanics Dr AVD
Grouting procedure 1.Penetration grouting.
A) Intrusion grotuing
 cementitious grouts are
injected through drill holes to
fill cracks & joints.
B) Permeation grouting
 Adopted during Tunneling
operation to make the
formation hard enough for
tunnel excavation.
Penetration Grouting
Permeation grouting

6. Grouting procedure 2.Compaction grouting or
Displacement grouting
Advanced engineering Geology With Rock Mechanics Dr AVD
 Thick stiff,grout injected under high pressure
through pipe.
 This method often adopted to repair
structures which have undergone excesive
settlement.
 Grout mass injected through a grout pipe set
in a drill hole forms a bulb around the place
where it is injected.
 compaction grouting carried out in different
steps
 At depth it is injected first,& grout pipe lifted
up to around 1 m & the grout is again
injected.
 Process repeated by pulling out grout in
stages untill the entire formation layer is
grouted.
Bulb
←
Compaction grouting

7. Grouting procedure 3. Jet grouting
Advanced engineering Geology With Rock Mechanics Dr AVD
 Jet grouting is the special method
developed in Japan.
 A special pipe equiped with horizontal
jets is used to forciblly injected the
grout material laterally.
 Grout mixes thoroughly with soil
resulted in a stronger & impermeable
grout mass of the soil.
 Wide ranges of uses including
construction of Cut-off walls,deep
foundation treatment in underpinning
operation. underpinning is the
method to stabilize foundation
systems mainly shallow foundation.
Horizontal jets→
Jet grouting

8. Typical Grouting Applications
Advanced engineering Geology With Rock mechanics Dr AVD
 In Dam construction grouting
carried out through grout
holes,prior to construction as in
case of Earthen & Masonary
Dams.
 In Concrete,Gravity & Thick Arch
Dams grouting is undertaken
through galleries & grout caps
during the construction of dam.
 For thin Arch dam grouting is
done through caps on the
upstream heal.
Grouting at Dam Foundation

9. Consolidation or Blanket grouting
Advanced engineering Geology With Rock Mechanics Dr AVD
 Grouting in this case to be
carried out & completed
prior to the constuction of
of the structure.
 Grout holes are placed in a
'grid-pattern'at specific
spacing & direction so as to
cover the desired portion
completely.

10. Advanced engineering Geology With Rock mechanics Dr AVD
 Curtain grouting form a gallery or a grout cap for
preventing leakages through foundation rocks.
 For the Earth & Rock-fill dams, the grout curtain is
placed along the axix of the dam, prior to the
constuction of the structure.
 However the grout procedure is adopted after
construction through the 'grout cap'at up-stream
heal of the dam.
 It is very effective if undertaken after the
construction of dam just around the 'period of
application of load' on the foundation.
 Normally a high pressure is adopted for grouting to
overcome resistance from the adjecent material.
 Depth of the grout curtain dependent on the local
geological conditions,However commonly a vertical
depth is chosen to be as one -third of dam height at
the grout hole location plus an additional depth of
20 m.
Curtain Grouting
Curtain grouting

11. Grout Consistancy & pressure
 Consistancy depends upon type of ' void spaces' & the nature
like particle size) of the grout suspension.
 In Engineering Terminology grout suspension is described as
thin,slimy or thick & stiff .
 Thin suspension have consistant quality of water ( up to about
8 times in volume as compared to the volume of grout
material)
 In thick grout water-grout material ratio normally corresponds
to 1:1
 compressive stength 4.2 MN/m2 for 28 days.
 Thickness 200- 300 m.
Advanced engineering Geology With Rock mechanics Dr AVD

12. Advanced engineering Geology With Rock Mechanics. Dr AVD