This document discusses compaction grouting and provides details on: 1. The mechanism of compaction grouting which uses low mobility grout pumped in stages to displace and densify surrounding soils through the formation of grout bulbs. 2. The typical procedures for compaction grouting including installing grout pipes, mixing and pumping grout to form intersecting grout bulbs in a staged process. 3. An example project where compaction grouting was used to improve ground conditions for NATM tunnel construction through filled soils by achieving the target SPT N-values. Testing showed the compaction grouting successfully increased SPT N-values as required.

1. Prof.dr. Adel el kelsh
ZAGAZIG UNIVERSITY
Faculty of Engineering
Submitted To :
Submitted By :
• Mohamed Gamal Husein
• Mahmoud Abdo Helal Ibrahim
• Hassan Mohamed Hassan
• Mostafa Osama Sharaf

2.  Contents
 Mechanism of treatment
 Grouting procedure
 Injection sequence
 Grouting parameters
 Equipment
 Material
 Effect of soil type and properties
 Design
 QA and QC
 Advantage and Disadvantage
 Limitation
 Others
 Issues for development
 List of references

3. Compaction grouting :

5. Mechanism of treatment
Uses displacement to improve
Ground Conditions a very viscous
{low modility}
Aggregate grout is pumped in stages
Forming grout bulbs which displace And
density
the surrounding soils Significant
improvement can be achieved
By sequencing the grouting work
From primary to secondary
to tertiary locations
‫ال‬compaction‫يستخدم‬‫االزاحات‬‫اللزوجة‬ ‫وتزويد‬ ‫التربة‬ ‫خواص‬ ‫لتحسين‬,‫ي‬‫تم‬
‫ال‬ ‫كرات‬ ‫ضخ‬grout‫الت‬ ‫كثافته‬ ‫من‬ ‫تزيد‬ ‫وبالتالي‬ ‫التربة‬ ‫ضغط‬ ‫علي‬ ‫تعمل‬ ‫التي‬‫ربة‬
‫المحيطة‬,

8. 1 Installation of the Grout Pipe
The grout pipe is either installed by means of a drill rig or a vibro hammer
depending on the soil and on the treatment requirements.
2 Compaction Grouting
The grout paste is prepared in the mixing plant and pressed into the soil by means of a
custom-built grout pump. While gradually pulling or penetrating the grout pipes,
individual intersecting grout bulbs are consecutively formed, thus creating column
shaped structural elements
‫تحضير‬ ‫يتم‬‫الجراوت‬‫المضخات‬ ‫طريق‬ ‫عن‬ ‫التربة‬ ‫في‬ ‫ويوضع‬ ‫الخلط‬ ‫مصنع‬ ‫في‬,‫تدريجي‬ ‫االختراق‬ ‫او‬ ‫االنابيب‬ ‫سحب‬ ‫ويتم‬‫ا‬
3 StagedCompaction
In order to achieve a uniform compaction of the soil, the injections are at first
executed in a large primary grid, and may be compacted further by means of a
secondary grid.
‫للتربة‬ ‫المنتظم‬ ‫الضغط‬ ‫تحقيق‬ ‫اجل‬ ‫من‬,‫الش‬ ‫في‬ ‫الضغط‬ ‫يمكن‬ ‫وال‬ ‫الكبرى‬ ‫االبتدائية‬ ‫الشبكة‬ ‫في‬ ‫البداية‬ ‫في‬ ‫الحقن‬ ‫يتم‬‫بكة‬‫الثاناوية‬

10. Injection sequence
1-Installation Of Grout Pipe:
- Drill or Drive Casing
-Record Ground Information from Casing
Installation
2- Initiation of Grouting:
- Typically a bottom up process
- Grout quality important
- Slow uniform stage injection
3- Continuation of Grouting:
- On-site batching of grout can aid control
- Sequencing of plan injection points very
important

16. Sand : Sand should conform to ASTM C-33
Cement. Cement (if used) should be Type I or Type II
Portland and free of contamination. Cement should be either
supplied in water resistant paper bags or in bulk. Cement
containing lumps should be rejected or screened to remove
lumps. ‫االسمنت‬ ‫رفض‬ ‫يتم‬‫اللذي‬‫كتل‬ ‫علي‬ ‫يحتوي‬
Flyash. Flyash (if used) should conform to ASTM C-618 and
be either Class C or Class F.
Lime : Lime (if used) should be hydrated agricultural lime ‫جير‬
‫زراعي‬ ‫.مطفي‬ Lime should be supplied in water resistant paper
bags or in bulk. Lime containing lumps should be rejected or
screened to remove lumps ‫الجير‬ ‫تصفية‬ ‫يتم‬‫اللذي‬‫ركام‬ ‫علي‬ ‫يحتوي‬ .
Water : Water should be clean and free from contamination
‫.تلوو‬ Volume shall be as necessary to achieve the desired
slump.
Admixtures : Admixtures such as a superplastizer or a
pumping aid may be added to increase set time or improve
pump ability.
Bentonite should be prehydrated if used , in order to prevent
bleeding and segregation ‫يكون‬ ‫ان‬ ‫يجب‬‫البنتونيت‬‫جافا‬

18. Drilling equipment Pump
Mixing Plant and  Grout header

24. Data required for the design of compaction grouting
consists of the followings as in other grouting
techniques:
• site geology and geotechnical parameters (soil
type, unit weight and structure),
• permeability of soil,
• temporality or permanence of the application,
• allowable soil or structural displacements,
• site access (open site or applications under the
existing structures).

25. Design Considerations
1-Preliminary Geotechnical
investigations
a-Determine scope of work
b-Delineate grouting boundaries
c-Testing methods
2-Drilling Methods
a-Augar
b-Rotary
c-Percussion
d-Vibratory
3-Grout Pipe Diameter
a-1.5 inch pipe (shallow)
b-3 inch pipe (deep)
4- Spacing of grout holes and design
depth
a-Linear
b-Grid
c-Angled vs. vertical
5-Sequence of grouting
a-Primary
b-Secondary
c-Tertiary
6-Method of grouting
a- Stage up
b- Stage down

26. QA/QC

32. Controls after the works
The results of the treatment are generally analysed by
reference to pressure meter or penetrometer tests.
These tests should be carried out as late as possible in
the treated areas, especially in soils with poor drainage.
Meaningful analysis is dependent on the same type of
tests having been carried out before commencement
of
the works.
‫يتم‬‫تحلبل‬‫االنتائج‬‫ال‬ ‫تجربتي‬ ‫طريق‬ ‫عن‬pressure meter‫او‬
penetrometer‫بقدر‬ ‫متأخر‬ ‫وقت‬ ‫في‬ ‫االختبارات‬ ‫هذه‬ ‫اجراء‬ ‫وينبغي‬
‫اإلمكان‬,‫السيئ‬ ‫التصريف‬ ‫ذات‬ ‫التربة‬ ‫في‬ ‫وخاصة‬

34. * Effective in a variety of soil conditions
*Wide applications range
Speed of installation*
*No need to connect to footing or
column

37. Like Any Ground Improvement TechniqueYouMust
Consider All Factors When Choosing A Remedial
Technique :
• The in situ vertical stress must be sufficient to enable the grout to displace the soil horizontally (if
ground surface heave occurs densification will be minimized). ‫كافي‬ ‫يكون‬ ‫ان‬ ‫يجب‬ ‫الراسي‬ ‫الضغط‬‫الزاحة‬‫افقيا‬ ‫التربة‬,
‫قليلة‬ ‫السطحية‬ ‫الكثافة‬ ‫فتكون‬ ‫وتهيج‬ ‫شقوق‬ ‫التربة‬ ‫لسطح‬ ‫حدث‬ ‫اذا‬ ‫ولذلك‬
• The grout injection rate should be slow enough to allow pore pressure dissipation.
• Sequencing of grout injection is also important.
• Soils that lose strength during remolding (saturated, fine‐grained soils; sensitive clays) should be
avoided.
• Greater displacement will occur in weaker soil strata. Exhumed grout bulbs confirm that
compaction
• Collapsible soils can usually be treated effectively with the addition of water during drilling prior to
compaction grout injection.‫قبل‬ ‫الحفر‬ ‫أثناء‬ ‫الماء‬ ‫ضافة‬
‫الجص‬ ‫حقن‬ ‫ضغط‬.
• Stratified soils, particularly thinly stratified soils, can be cause for difficult or reduced improvement
capability. ‫التحسين‬ ‫كفاءة‬ ‫من‬ ‫تقلل‬ ‫ات‬ ‫يمكن‬ ‫الرقيقة‬ ‫الطبقية‬ ‫التربة‬ ‫وخاصة‬ ،‫الطبقية‬ ‫لتربة‬

40. COMPACTION GROUTING FOR NATM
TUNNEL AT SAKET
• NAME : NATM TUNNEL
• LOCATION : SAKET IN SOUTH DELHI INDIA .
• PROBLEM : TUNNEL EXCAVATION BY NATM WAS
PROPOSED AT A DEPTH OF ABOUT 9 M BELOW
EXISTING GROUND LEVEL. THE SOIL ABOVE THE
TUNNEL CROWN IS FILL MATERIAL (ALONG THE
NALLAH ALIGNMENT) CONSISTING OF SANDY
SILT/SILTY SAND IN THE TOP 5 TO 6 M. THIS WAS
FOLLOWED BY DELHI SILT ALLUVIUM DOWN TO THE
TUNNEL CROWN. FIG. 8 ILLUSTRATES THE LAYOUT OF
THE NATM TUNNELS AND THE ALIGNMENT OF
NALLAH CHANNEL.

41. Fig. 8: Layout of the NATM Tunnels and abandoned Nallah channel
NATM: is a method where the surrounding rock or soil
formations of a tunnel are integratedinto an overall ring-like
support structure

42. SOIL CONDITIONS
THE SOILS AT SITE GENERALLY CONSIST OF
SANDY SILT FILL TO 5M DEPTH. THE ABANDONED
NALLAH CHANNEL WAS EXCAVATED AND FILLED
WITH LOCALLY AVAILABLE SANDY SILT TO LEVEL
THE GROUND. SPT N VALUES IN THE SANDY SILT
FILL WERE IN THE RANGE OF 4 TO 17,
INDICATING LOOSE TO MEDIUM DENSE.
THIS WAS FOLLOWED BY MEDIUM DENSE TO
DENSE DELHI SILT ALLUVIUM LAYER, WITH SPT N
VALUES BETWEEN 20 & 30 TO ABOUT 26 M DEPTH.
THIS IS UNDERLAIN BY MODERATELY
WEATHERED QUARTZITE BEDROCK.

43. GEOTECHNICAL REQUIREMENT
HENCE, IN ORDER TO PERMIT SAFE AND STABLE NATM TUNNEL
EXCAVATION AND PRIMARY LINING CONSTRUCTION, IT WAS
NECESSARY TO CARRY OUT A COMBINATION OF SHALLOW AND
DEEP GROUND TREATMENT BY COMPACTION GROUTING.
AN THEORETICAL SPT ‘N’ VALUE PROFILE BETWEEN 10 AND 18 WITH
RESPECT TO DEPTH WAS PROPOSED BY USING THE CORRELATION,
SPT N = 10 + 1.75Z, WHERE, Z IS DEPTH, TO FORM EFFECTIVE SOIL
ARCHING DURING TUNNEL CONSTRUCTION. ‫بين‬ ‫ما‬ ‫قيمة‬ ‫علي‬ ‫الحصول‬ ‫يراد‬
10‫الي‬18‫المعادلة‬ ‫في‬ ‫التعويض‬ ‫يتم‬ ‫عليها‬ ‫وللحصول‬
SPT N = 10 + 1.75Z

44. Fig. 9 illustrates the proposed NATM tunnels under a filled up soil strata at
abandoned
Nallah channel location along with the existing and required SPT N value
profile.

45. INSTALLATION METHOD
1. GENERALLY CONSTRUCTION CONSISTS OF DRILLING, INSTALLATION OF STINGER
RODS AND PUMPING THE LOW SLUMP GROUT MIX FROM THE BOTTOM OF THE
TREATMENT DEPTH TO THE WORKING PLATFORM IN STEPS.
2. FOR COMPACTION GROUTING, A LOW SLUMP CEMENT WITH A MIX PROPORTION
OF 1:3 , WATER-CEMENT RATIO OF 0.5 AND ADMIXTURES LIKE BENTONITE AND
GLENIUM ARE USED AS A PLASTICIZER TO INCREASE THE WORKABILITY OF GROUT
MIX. THE SLUMP VALUE OF GROUT MIX IS ABOUT 120 TO 150 MM.
3. A TRUCK MOUNTED HYDRAULIC DRILL RIG WAS USED TO DRILL A NOMINAL
DIAMETER HOLE OF 90 MM TO A DEPTH OF ABOUT 8 M THROUGH THE OVER
BURDEN SOILS.
4. AFTER DRILLING, THE GROUT MIX WAS PUMPED THROUGH THE STINGER RODS, TO
FORM A BULB LIKE ELEMENT IN THE LOOSE SOILS, IN STAGES (0.5 M EACH) FROM
BOTTOM TO THE TOP OF THE WORKING PLATFORM. FIG. 10 SHOWS THE
COMPACTION GROUTING WORKS AT SITE.

46. Fig. 10
a) Picture illustrating the progress of
compaction grouting works at site
b) Measurement of
slump as QA-QC procedures

47. TESTING RESULTS
• FIELD TRIALS WERE CARRIED OUT TO ESTABLISH A SUITABLE GRID PATTERN TO
ACHIEVE THE INTENDED POST
• COMPACTION GROUTING SPT ‘N’ VALUES. TRIALS WERE CARRIED USING 2 M AND 4
M SQUARE GRIDS.
• PRE AND POST COMPACTION GROUTING SPT ‘N’ VALUES WERE RECORDED AND
ANALYSED.

48. • A TOTAL OF 296 GROUT POINTS WERE DRILLED WITH OVER
420 M3 OF GROUT PUMPED. 19 PREIMPROVEMENT
• AND 17 POST-IMPROVEMENT SPT BOREHOLES WERE DRILLED.
THE NATM TUNNEL
• EXCAVATION WAS SUCCESSFULLY COMPLETED IN THE MIDDLE
OF 2009.
PERFORMANCE OF IMPROVED GROUND

49. POST TREATMENT SPT ‘N’ VALUES IN THE FILLED UP SOIL INCREASED
AND RANGED BETWEEN 20 & 30. FOR BOTH 2 M AND 4 M GRIDS
WERE GENERALLY ABLE TO ACHIEVE THE REQUIRED DESIGN SPT N
VALUES.

50. QUALITY ASSESSMENT AND CONTROL
THE WORKING PARAMETERS (E.G DEPTH, PRESSURE, GROUTVOLUME,
HEAVE ETC) WERE MAINTAINED AND RECORDED AT EACH STAGE OF
COMPACTION GROUTING PROCESS TO DETERMINE THE APPROPRIATE
TERMINATION POINT. TERMINATION OF PARTICULAR GROUTING STAGE
WAS CONSIDERED WHEN ONE OF THE FOLLOWING CONDITIONS
ACHIEVED :
• PRE-DETERMINED GROUT VOLUME IS ACHIEVED (IN ACCORDANCE WITH BULB
DIAMETER I.E., 0.5 M)
• PRE-DETERMINED GROUT PRESSURE IS ACHIEVED (IN ACCORDANCE WITH DEPTH
OF TREATMENT I.E.,12 KG/SQ.CM TO 18 KG/SQ.CM)
• MORTAR IS OVERFLOWING FROM SAME GROUT HOLE COLLAR
• EXCESSIVE GROUND HEAVE IS MEASURED I.E. GREATER THAN OR EQUALS TO 15
MM

51. REFERENCES
• BS 8081: 1999, “BRITISH STANDARD CODE OF PRACTICE FOR
GROUND ANCHORAGES”, BRITISH
• STANDARDS INSTITUTE, LONDON.
• IS 14268: 1995, “SPECIFICATION FOR UNCOATED STRESS RELIEVED
LOW RELAXATION SEVEN PLY STRAND
• FOR PRESTRESSED CONCRETE”, BUREAU OF INDIAN STANDARDS,
NEW DELHI.