Grouting Methods
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This document discusses different grouting methods. It describes permeation grouting where grout is injected to fill voids without disturbing soil grains. Displacement grouting displaces soil grains, including compaction grouting using thick grout to form bulb shapes, and soil fracture grouting using lean grout to form root-like lenses. Jet grouting forms grouted columns by partly replacing and mixing with soil. Permeation grouting is used to form seepage barriers and stabilize tunnels. Displacement-compaction grouting involves high pressure injection of a soil-cement grout mixture to form 0.5-1m bulbous intrusions.
Grouting Methods
- 1. R.V.Kolhe Grouting METHODS BY Prof. Rushikesh v. Kolhe Department of Civil engineering Sanjivani college of Engineering
- 2. R.V.Kolhe Grouting • INJECTION OF SLURRY/LIQUID SOLUTION INTO ROCK OR SOIL. • INJECTED MTRL IS GROUT • TECHNIQUE DEVELOPED FOR MAKING VERTICAL SEEPAGE BARRIER BY CEMENT SLURRY. • CEMENTING CAPABILITY INCREASES SOIL/ROCK STR. • CEMENT SLURRY IS NON-PERMEABLE SO SPL CHEMICALS WERE INVENTED.
- 3. R.V.Kolhe TYPE OF GROUTS • SUSPENSIONS – CEMENT OR BENTONITE GROUT • EMULSIONS- BITUMEN EMULSIONS • SOLUTIONS- SODIUM SILICATE OR ACRYLIC RAISIN.
- 4. R.V.Kolhe DESIRABLE CHAR OF GROUTS • STABLITY: CAPABLITY OF GROUT TO REMAIN IN FLUID STATE. – GROUT NOT TO SEGREGATE BEFORE REACHING DESTINATION. – STABLITY OF CLAY CEMENT GROUT > CEMENT GROUT
- 5. R.V.Kolhe DESIRABLE CHAR OF GROUTS • SETTING TIME : TIME TO SET TO CEMENTED MASS OR GEL. – EARLY SETTING : REACHING DESTINATION. – LATE SETTING: GROUT WASHED AWAY. (SEEPAGE) – RETARD OR ACCELERATE BY ADDITIVES
- 6. R.V.Kolhe DESIRABLE CHAR OF GROUTS • PERMANENCE: RESISTANCE OF GROUT AGAINST DISPLACEMENT FROM SOIL WITH TIME. – CEMENT GROUTS > BENTONITE GROUT ( WASHED AWAY BY SEEPAGE WATER)
- 7. R.V.Kolhe DESIRABLE CHAR OF GROUTS • TOXICITY: CONTAMINATE SURROUNDING SOIL AND GROUND WATER. • HEALTH HAZARD
- 8. R.V.Kolhe TYPES OF GROUTING TECHNIQUES • GROUTING METHODS FOR SOILS ARE CLASSIFIED AS: (I) PERMEATION GROUTING (II) DISPLACEMENT-SOIL FRACTURE GROUTING (III) DISPLACEMENT-COMPACTION GROUTING (IV) JET OR REPLACEMENT-DISPLACEMENTGROUTING
- 9. R.V.Kolhe PERMEATION GROUTING If the injection of grout in soil is done in a manner that the arrangement of the soil grains is not disturbed and only the void space is filled by a process of permeation, that is, seepage, the method is referred to as permeation grouting as shown in fig.
- 11. R.V.Kolhe If, however, the process of injection displaces the soil grains, the method is termed as displacement grouting. Displacement grouting is further divided into two sub— types, namely, compaction grouting and soil fracture grouting. Compaction grouting consists of injecting a thick viscous paste—like slurry at high pressure to form a bulb shaped grouted mass in soil as shown in fig.
- 12. R.V.Kolhe On the other hand when lean slurry of high fluidity is injected into the soil at high pressure to form root-like lenses of grout material in the soil mass as depicted in fig. , the method is termed as soil fracture grouting.
- 14. R.V.Kolhe In yet another method the grout material is injected into the soil mass in the form of a jet to form a grouted column as shown in fig. by partly replacing the soil, partly mixing with the remaining soil and also through displacing the soil. This method is referred to as jet grouting or replacement- displacement grouting.
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- 17. R.V.Kolhe Permeation Grouting • CEMENT GROUTS, BENTENITE GROUTS AND CHEMICAL GROUTS ARE USED FOR PERMEATION GROUTING AS SUMMARIZED 1N TABLE. • CHEMLCAL GROUTS ARE SUITABLE FOR THE MAXIMUM RANGE OF GRAIN SIZES BUT THEY ARE VERY EXPENSIVE
- 18. R.V.Kolhe PERMEATION GROUTING • Cement grout not only fills the voids and reduces permeability but also sets with time and binds the soil grains together. As a consequence, the strength of the soil mass increases and its compressibility decreases. Sometimes cement in grout is replaced by clay to reduce cost. solved • When the objective of grouting is only to reduce permeability, bentonite grouts can be used. However, the permanence of such grouts under high hydraulic gradients is questionable and often cement is added.
- 19. R.V.Kolhe • Permeation grouting is widely used for making vertical seepage barriers beneath hydraulic structures as shown in fig. • It is also used for stabilization of soil around tunnels and shafts as depicted in fig. (b). • other uses include stoppage of seepage through joints of underground structures such as tunnel lining, basement wall etc.
- 20. R.V.Kolhe GROUTING PLANT FOR PERMEATION (CEMENTGROUT ) • Grout slurry is prepared by mixing cement with water in a slow- speed paddle mixer followed by a high-speed agitator. • A positive displacement pump (reciprocating or diaphragm type) is- used for pumping the slurry into a grout supply line (pipe of 30' to 50 mm diameter) which transports the slurry under pressure to the point of injection in the soil. • The grout pipe is lowered into the grout hole that has already been drilled to the grouting point. • The annularspace between the grout hole and grout pipe is sealed and the grout slurry injected into the soil at the prescribed pressure. • Packers, in the form of leather cups or inflatable rubber seals, are used for Sealing the annular space—see Fig. 31,4,
- 21. R.V.Kolhe • when the grouting has to be executed down to the shallow depth below the ground surface (few meters. • Grout hole is drilled completely. • grout pipe is inserted from top • annular spaces are sealed and grouting is done under low pressure
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- 26. R.V.Kolhe Descending and Ascending Stage Grouting: • For grouting to larger depths, grouting is executed in stages. • In the DESCENDING STAGE grouting, drilling and grouting are executed alternatively in stages of 3 to 5 m in the downward direction as shown in Fig. • For each stage, as one goes deeper, one can use higher grout pressure. • ASCENDING STAGE grouting shown in Fig. is executed in a reverse manner • The grout hole is drilled to the full depth in one operation. • Subsequently the grout pipe is lowered to the deepest segment of the hole and the annular space sealed using a packer. • Grouting is carried out at high pressure. Thereafter, the grout pipe and the packer is raised in stagesof3 to 5 m and the
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- 29. R.V.Kolhe Descending and Ascending Stage Grouting: • ASCENDING STAGE GROUTING HAS THE ADVANTAGE THAT THE DRILLING IS ALL DONE IN ONE GO. • IN DESCENDING STAGE GROUTING, ONE CAN USE HIGHER GROUT PRESSURES AS ONE MOVES TO LOWER STAGES • NOT ONLY BECAUSE OF GREATER DEPTH BUT ALSO BECAUSE THE UPPER LEVELS HAVE BEEN GROUTED AND THE SOIL FORMATION IS MORE FIRM ESPECIALLY WHEN GROUTS USED ARE OF TYPES THAT SET AND ADD TO STRENGTH.
- 30. R.V.Kolhe GROUTING USING SLEEVED PIPE • ASCENDING STAGE GROUTING IN SOIL MAY BE HAMPERED DUE TO IMPROPER FUNCTIONING OF PACKERS WHEN PUSHED OR EXPANDED AGAINST AN UNEVEN GROUT HOLE WALL. • HENCE SLEEVED PIPE GROUTING DEPICTED IN FIG. 31.8 IS OFTEN MORE SUCCESSFUL. IN THIS A SLOTTED PIPE, HAVING VERTICAL SLOTS COVERED WITH THIN RUBBER SLEEVES, IS LOWERED INTO THE GROUT HOLE. • THE SPACE BETWEEN THE SLOTTED PIPE AND THE GROUT HOLE IS SEALED WITH CEMENT-BENTONITE SEAL. • GROUTING IS DONE BY LOWERING THE GROUT PIPE WITH A PAIR OF PACKERS TO THE DESIRED ELEVATION INSIDE THE SLOTTED PIPE AND INJECTING THE GROUT UNDER PRESSURE. • GROUT PRESSURE BRUSTS THE TEMP RUBBER SLEEVE AND CEMENT BENTONITE SEAL. • GROUT PERMEATES INTP ADJOINING SOIL.
- 31. R.V.Kolhe Grouting using sleeved pipe
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- 33. R.V.Kolhe Grouting using sleeved pipe
- 34. R.V.Kolhe Grouting using sleeved pipe
- 35. R.V.Kolhe CURTAIN GROUTING • GROUTING ARRANGEMENTS THAT PERMEATION GROUTING IS OFTEN USED FOR MAKING VERTICAL SEEPAGE BARRIERS BENEATH HYDRAULIC STRUCTURES HAS ALREADY BEEN HIGHLIGHTED EARLIER. • THIS GROUTING ARRANGEMENT IS CALLED CURTAIN GROUTING. TYPICALLY, GROUTING IS CARRIED OUT TO THE REQUIRED DEPTH ALONG 2 TO 3 ROWS OF GROUT HOLES. • THE GROUT HOLES IN EACH ROW MAY BE SPACED AT 2 TO 4 M AND STAGGERED IN PLAN ALONG THE ROWS. • GROUTING IS FIRST DONE IN PRIMARY HOLES SPACED 15— 25 M APART FOLLOWED BY SECONDARY HOLES AT INTERMEDIATE LOC AND THEN TERTIARY HOLES AT 2—4 M SPACING AS SHOWN IN FIG. 31.9.
- 37. R.V.Kolhe BLANKET GROUTING • IT REFERS PERMEATION GROUTING CARRIED OUT OVER A LARGE AREA IN PLAN DOWN TO A SHALLOW FIXED DEPTH. • SUCH A GROUTED ZONE IN THE SHAPE OF A BLANKET IS OFTEN CREATED BEHIND HYDRAULIC STRUCTURE TO REDUCE WATER LOSS BY SEEPAGE FROM THE RESERVOIR, • THE GROUTED BLANKET INCREASES THE SEEPAGE PATH. • GROUTING IS FIRST EXECUTED IN PRIMARY HOLES AT A GRID SPACING OF ABOUT 20 M FOLLOWED BY SECONDARY HOLES AT A GRID SPACEING OF ABOUT
- 38. R.V.Kolhe 10 M AND FINALLY IN A CLOSELY SPACED TERTIARY GRID OF HOLES AT A SPACING OF ABOUT 5 M.
- 40. R.V.Kolhe DISPLACEMENT-COMPACTION GROUTING • INJECTION OF GROUT UNDER HIGH PRESSURE IN SOIL MASS. • CAUSES DISPLACEMENT OF SOIL PARTICLES. • BULBOUS/SPHERICAL SHAPED INTRUSIONS RANGE OF 0.5 TO 1.0 M ARE FORMED. • THE GROUT MATERIAL USED IS A MIXTURE OF SOIL AND CEMENT, SEE TABLE 31.2. • • THE SOIL USED IN THE GROUT HAS SUFFICIENT SAND SIZED PARTICLES TO DEVELOP INTERNAL FRICTION AS WELL AS ENOUGH FINE GRAINED PARTICLES TO PROVIDE PLASTICITY TO THE GROUT.
- 41. R.V.Kolhe DISPLACEMENT-COMPACTION GROUTING • WATER IS ADDED TO YIELD A PASTE-LIKE CONSISTENCY OF THE GROUT. • WE NEED TO USE JUST ENOUGH CEMENT SO THAT THE ENGINEERING PROPERTIES OF THE GROUTED MASS ARE SIMILAR TO OR BETTER THAN THOSE OF THE NATURAL SOIL IN A COMPACTEDSTATE. • IN SOME CASES, WHEN PERMANENCE IS NOT AN ISSUE, CEMENT NEED NOT BE USED AT ALL AND THE GROUT CAN BE JUST A SOIL SLURRY.
- 43. R.V.Kolhe DISPLACEMENT-COMPACTION GROUTING • THE TECHNOLOGY OF INJECTION OF GROUT IS SIMILAR TO THAT FOR PERMEATIONGROUTING. • HOWEVER, SINCE THE GROUT MIX IS MUCH STIFFER THAN IN PERMEATION GROUTING AND GROUT PRESSURES ARE MUCH HIGHER, THE GROUT PUMPS USED ARE HEAVY-DUTY CONCRETE PUMPS. • GROUT PIPE DIAMETERS RANGE FROM 50 TO 75 MM. • THE QUANTITY OF GROUT INJECTED IS OBSERVED TO RANGE FROM 3 TO 12 PERCENT BY VOLUME OF THE TREATED LOOSE SOIL, • DISPLACEMENT-COMPACTIONGROUTING IS SUITABLE FOR ALL TYPES OF LOOSE COARSE GRAINED SOILS, SOFT FINE GRAINED SOILS WHICH ARE NOT SATURATED AND FOR FILLING UNDERGROUND CAVITIES. • IT IS NOT USED IN SOFT SATURATED FINE GRAINED SOILS BECAUSE GROUTING RAISES THE PORE WATER PRESSURE IN THE SOIL MASS LEADING TO UNEVEN AND AGGRAVATED SETTLEMENT PROBLEMS.
- 44. R.V.Kolhe DISPLACEMENT-COMPACTION GROUTING • IN COMPARISON TO OTHER TYPES OF GROUTING, DISPLACEMENT— COMPACTION GROUTING IS OBSERVED TO BE USEFUL FOR THE FOLLOWING SITUATIONS: • (I) DENSIFICATION OF THIN LOOSE STRATUM UNDERLYING DENSE SOIL AND LOCATED AT CONSIDERABLE DEPTH—SEE FIG. 31.11(A) AND (B) • (II) DENSIFICATION OF POCKETS OF LOOSE SOILS BENEATH FOUNDATIONS OR FLOOR SLABS THAT ARE REVEALED AFTER CONSTRUCTION IS COMPLETED INCLUDING LEVELING OF SUNKEN FLOORS—ALSO REFERRED TO AS SLAB-JACKING OR BACK- PACKING— SEE FIG. 31.11(C),
- 45. R.V.Kolhe DISPLACEMENT-COMPACTION GROUTING • (III) FILLING OF LARGE UNDERGROUND CAVITIES CAUSED BY BROKEN UNDERGROUND UTILITY LINES, BY PIPING/ EROSION, OR BY DISSOLUTION AS DEPICTED IN FIG. 31.11(D) AND (E); IN SUCH CASES, THE CAVITIES ARE FIRST FILLED WITH GROUT AND THEN THE DENSITY OF SURROUNDING SOIL IS INCREASED BY GROUTING WITH APPROPRIATE GROUT PRESSURE, AND • (IV) DENSIFICATION OF SOILS SHOWING ORGANIC DEGRADATION WITH TIME. DISPLACEMENT-COMPACTION GROUTING IS MOST OFTEN USED IN SMALL AREAS OR POCKETS AS A REMEDIATION TECHNIQUE. IT IS RARELY COST EFFECTIVE FOR GROUND IMPROVEMENT OVER LARGE AREAS.
- 50. R.V.Kolhe Displacement—Soil Fracture Grouting • SOIL FRACTURE GROUTING TECHNIQUE IS A DISPLACEMENT GROUTING TECHNIQUE IN WHICH A LEAN 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. •
- 52. R.V.Kolhe SUCH GROUTING ALSO CAUSES THE GROUND TO HEAVE AND THAT CAN BE USED TO ADVANTAGE, FOR EXAMPLE, IN RECTIFYING TILT IN BUILDINGS AND RESTORING THEIR VERTICALITY AS SHOWN IN FIG. 31.12.
- 53. R.V.Kolhe Restoration of verticality of a tilted building • RESTORATION OF VERTICALITY OF A TILTED BUILDING SUCH GROUTING IS USUALLY ACCOMPLISHED USING THE SLEEVED PIPE GROUTING TECHNIQUE AS DEPICTED IN FIG. 31.13. • GROUT HOLES, 100 MM IN DIAMETER, ARE DRILLED AT REGULAR INTERVALS AND SLEEVED PIPES WITH MULTIPLE SLOTS ARE PLACED IN THE GROUT HOLES. GROUTING IS DONE IN SEGMENTS OF 0.3 TO 1.0 M ALONG THE LENGTH OF EACH SLOTTED PIPE USING GROUT PRESSURES AS HIGH AS 4000 KN/MZ.
- 55. R.V.Kolhe Jet or Replacement—Displacement Grouting • 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. • THE TECHNIQUE IS CALLED REPLACEMENT DISPLACEMENT BECAUSE A PART OF THE SOIL IS REMOVED BY THE JETTING ACTION AND IS REPLACED BY THE GROUT MATERIAL AND BECAUSE THE GROUT IS INJECTED AT HIGH PRESSURE PARTLY TO MIX WITH THE REMAINING SOIL AND BARTLY TO DISPLACE THE SURROUNDING SOIL.
- 56. R.V.Kolhe Jet or Replacement—Displacement Grouting • THE GROUT MATERIALS USED ARE CEMENT AND WATER WITH SOME ADDITIVE AS INDICATED IN TABLE 31.3. • JET GROUTING IS THE YOUNGEST OF GROUTING TECHNIQUES AND CONSULTING GEOTECHNICAL ENGINEERS HAVE BEGUN TO USE IT AFTER THE MID-1980S. • IT IS MORE EXPENSIVE THAN PERMEATION GROUTING, DUE TO LARGER CONSUMPTION OF CEMENT PER UNIT VOLUME OF SOIL MASS TREATED.
- 57. R.V.Kolhe • NEVERTHELESS, IT IS NOW EXTENSIVELY USED AS IT PRODUCES MORE UNIFORM GROUTING, CAN BE USED IN MOST SOILS AND HAS A HIGHER RATE OF PRODUCTIVITY
- 59. R.V.Kolhe Jet or Replacement—Displacement Grouting • TYPES OF JET GROUTING – SINGLE JET OR ONE FLUID SYSTEM – DOUBLE JET OR 02 FLUID SYSTEM – TRIPLE JET OR 03 FLUID SYSTEM. • THE FIRST STEP IS TO DRILL A GROUT HOLE OF 100 TO 150 MM DIAMETER. • THE HOLE IS KEPT STABLE BY USING WATER CIRCULATION OR BENTONITE SLURRY CIRCULATION. • IN THE SECOND STEP, JETTING COMMENCES IN THE HORIZONTALDIRECTION THROUGH NOZZLES (2 TO 4 MM IN DIAMETER)AT THE TIP OF THE MONITOR THAT IS ROTATED AT 5 TO 30 REVOLUTIONS PER MINUTE. • THE SOIL CUTTINGS TRAVEL TO THE GROUND SURFACE THROUGH THE ANNULAR SPACE BETWEEN THE BOREHOLEAND THE MONITOR. • THE MONITOR IS LIFTED AT A RATE OF 50 TO 300 MM PER MINUTE IN THE THIRD STEP RESULTING IN THE FORMATLON OF A GROUTED COLUMN.
- 61. R.V.Kolhe • IN THE SINGLE JET SYSTEM, A HORIZONTAL JET OF GROUT AS SHOWN IN FIG. SIMULTANEOUSLY ERODES THE SOIL AND MIXES WITH A PART OF THE REMAINING SOIL TO FORM A GROUTED COLUMN. • IN THE DOUBLE JET SYSTEM, THE EROSIVE EFFECT OF THE GROUT JET IS CONSIDERABLY ENHANCED BY THE ADDITION OF A SHROUD OF COMPRESSED AIR • THE TRIPLE JET SYSTEM USES A WATER JET SHROUDED BY AIR TO ERODE THE SOIL AND A SEPARATE NOZZLE BENEATH THE WATER JET TO PLACE THE GROUT AS DEPICTED IN FIG. 31.15(C).
- 62. R.V.Kolhe GROUTED COLUMNS -DIAMETER • JET GROUTED COLUMNS CAN BE FORMED IN ALMOST ALL TYPES OF SOILS RANGING FROM SANDY GRAVELS TO CLAYS. • SANDS ARE BEST SUITED FOR TREATMENT YIELDING THE LARGEST DIAMETER OF COLUMNS. • PRESENCE OF INTERPARTICLEATTRACTIVE FORCES REDUCES THE EROSIVE EFFICIENCY OF THE JETS. • HENCE DIAMETERSOF GROUTED COLUMNS ARE PROGRESSIVELY SMALLER IN SANDY SILTS, SILTS, CLAYEY SILTS AND CLAYS. • 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 VIA THE ANNULAR SPACE BETWEEN THE GROUTHOLE AND THE MONITOR. • SANDY GRAVEL CAN BE TREATED BY JET GROUTING. • JET GROUTED COLUMN DIAMETERS IN SANDS, SILTY SANDS AND CLAYEY SILTS ARE TYPICALLY OF THE ORDER OF – 1.0, 0.85 AND 0.5 M RESPECTIVELY FOR SINGLE JET SYSTEM AND – 2.0, 1.5 AND 1.0 M RESPECTIVELY FOR TRIPLE JETSYSTEM.
- 63. R.V.Kolhe THE TRIPLE JET SYSTEM IS THE MOST EFFECTIVE IN REMOVING SOIL AND GIVES THE LARGEST DIAMETER OF GROUTED COLUMNS AMONGST THE THREE SYSTEMS. IN EACH SYSTEM, THE DIAMETER OF THE GROUTED COLUMN CAN BE VARIED BY CHANGING THE RATE OF WITHDRAWAL OF THE MONITOR. FIG. SHOWS THE COMPONENTS OF EQUIPMENT FOR TRIPLE JET GROUTING.
- 64. R.V.Kolhe ROWS OF GROUTED COLUMNS AS SHOWN IN FIG. ARE USED BENEATH DAMS TO FORM SEEPAGE BARRIERS WITH COEFFICIENT OF PERMEABILITY IN THE RANGE OF 10 -7 TO 10 -9 M/SEC.
- 65. R.V.Kolhe SUB-HORIZONTAL JET GROUTED COLUMNS ARE USED FOR STABILIZATION OF SOIL DURING TUNNELING
- 66. R.V.Kolhe OTHER APPLICATIONS OF JET GROUTING ARE FOR EARTH RETENTION IN DEEP EXCAVATIONS AS SHOWN IN FIG