![2. Joint Width and Continuity
The easiest joints to grout
have widths in the range
between about 0.250 in [6
mm] and 0.020 in [0.5 mm].
Continuity of open jointing
systems affects penetration:
lack of continuity means
that more grout holes will
be needed than if grout can
travel appreciable distances
through the systems.](https://image.slidesharecdn.com/groutingtechnology-gunturchapter-230114133248-06edc36d/85/Grouting-Technology-Guntur-Chapter-ppt-51-320.jpg)
![When grout holes are longer than about 30
ft [10 m], it is usually best to divide them
into shorter lengths, called stages, and
grout each of these stages separately.](https://image.slidesharecdn.com/groutingtechnology-gunturchapter-230114133248-06edc36d/85/Grouting-Technology-Guntur-Chapter-ppt-63-320.jpg)
Grouting Technology - Guntur Chapter.ppt
- 1. 58th Webinar on Grouting Technology for Civil Engineering Applications 11th December,2020 Organised by IGS – Guntur Chapter IGS – Student Chapter GUDLAVALLERU ENGINEERING COLLEGE 1
- 2. Thanks to IGS – Guntur Chapter Good Morning
- 7. VARIOUS GROUND IMPROVEMENT TECHNIQUES TREATMENT SHALLOW LAYERS TREATMENT OF DEEP LAYERS Compaction Stabilization Freezing & Heating Geotextile Reinforced Earth CNS Layer Dynamic compaction and consolidation Vibroflotation Compaction pile Blasting Heavy tamping Pre-compression – Vertical drain Electro Osmosis Lime piles and columns Stone columns Grouting
- 9. Dr. D.L.SHAH Professor (Retd.), M S University of Baroda. Senior Consultant, GEO DYNAMICS Chairman, Indian Geotechnical Society – Baroda Chapter Consultant to SSNNL, Govt of Guj. dr_dlshah@yahoo.com Grouting Technology for Civil Engineering Applications
- 11. Definition Grouting is a process of injection of setting fluids in to the voids of the alluvium, or into the fissures of the rock either to reduce permeability or to increase strength or both. Injected fluid (grout) will solidify by physico-chemical or by chemical action with the passage of time and thereby increases the strength and reduces the permeability. The success of the grouting is mainly dependent on selection and type of grout materials and suitable grouting techniques.
- 12. FUNCTIONS OF GROUTING Permeation Compaction Jet Grouting
- 14. Civil Engineering Applications of Grouting Alluvial Grouting of Earth Dam Foundations Alluvial Grouting of Building Foundations Rock Grouting of Masonry and Concrete Dam foundations Grouting During Pipe Jacking Operation Grouting of Foundation Soils of Existing Machine Foundations. Grouted Anchors. Grouted Mattress for Seepage and Leakage Control in Perennial Canal Microfine Cement Grouting in Tunnelling and other Applications Crack Grouting for Rehabilitation of Building and Dams Jet Grouting for Deep Foundations & Tunnels
- 15. Alluvial Grouting for Earth Dam Foundation Concrete Gravity Dam with Intersecting Fault Zone Concrete rch Dam Resist Unstable Movements
- 16. Soil Stabilization, Tunnel Construction
- 17. Vibration Isolation for Machine Foundation Cement/Chemical injection of foundation media is a recent innovation in decreasing vibration. Such injection results in increased rigidity of the base and consequently increased natural vibration of the foundation. Increased rigidity increases the difference between the frequency of natural vibration and the frequency of the machine. Consequently the amplitudes of foundation vibration are decreased. The injection method has the special advantages of non-interruption of work of the machine during the treatment.
- 18. Compaction & Jet Grouting
- 22. Controlled Lifting with Compaction Grouting Correction of Structural Settlement (a) from the top down (b) from the bottom up
- 24. Compaction Grouting For Increasing End Bearing And Friction
- 25. Jet Grouting
- 26. Execution Phases
- 27. Jet Grouting • A relatively new and one of the most successful techniques • A speed jet of water released from a 1 to 2 mm nozzle at the end of a grout pipe at a pressure of 200 to 5000 kg/cm2 cuts through the soil or soft rock. • When the slot has been formed, a chemical solution grout is substituted for the water and stabilizes in place as a solid mass. • The grout pipe is lifted from bottom of the hole as process continues.
- 28. Various Applications of Jet grouting
- 29. Consolidation & Underpinning for deep excavation close to existing buildings Underpinning of Existing Buildings
- 30. foundations of viaduct piles Building Foundation improvement
- 32. Dam Grouting
- 33. An outline of Grouting from beginning to end •Investigation •Decide whether grouting necessary or not •Design •Site preparation •Equipment •Drilling •Water testing •Hook-up •Commencing grouting •Looking for trouble •Review of mix •Completion •Assessment •Long term performance
- 38. Rock Grouting
- 39. WHEN IS GROUTING WARRANTED??
- 41. The Lugeon Test The Lugeon Test The most commonly in-situ test used to estimate hydraulic conductivity of rock masses is the Lugeon test – also called the packer test. The test, which derives its name from Maurice Lugeon (1933), is a constant head type test that takes place in an isolated portion of a borehole. Water at constant pressure is injected into the rock mass through a slotted pipe bounded by pneumatic packers. A pneumatic packer is an inflatable rubber sleeve that expands radially to seal the annulus space between the drill rods and the boring walls.
- 42. One Lugeon value, which is empirically defined as flow rate of 1 liter/minute per meter of test hole under a reference water pressure equal to 1 MPa
- 46. Use of Automated Data Acquisition System Automated data acquisition systems capable of measuring, displaying and recording Lugeon test and grouting data in Real Time have become available over the last years. This equipment measures flow rate and pressure at regular intervals of time and displays the information on an LCD display.
- 47. • To give a sense of proportion for the unit: • 1 lugeon unit is the type of permeability where grouting is hardly necessary. • 10 lugeons warrants grouting for most seepage reduction jobs. • 100 lugeons is the type of permeability met in heavily jointed sites with relatively open joints or in sparsely cracked foundations where joints are very wide open.
- 49. Adapting Grouting to Suit the Geology Features that can influence grouting design and construction include: • 1. Spacing of Joints • 2. Joint Widths and Continuity • 3. Joint Inclination • 4. Uniformity of the Site • 5. Rock Soundness • 6. Strength • 7. Piping
- 50. 1. Spacing of Joints As far as cement grouting is concerned, it is the open, groutable joints that are of interest. If they are widely spaced, the grouting is usually easier than if closely spaced where troubles such as frequent surface leaks, collapsing holes and patchy penetrations can happen. These make for more expensive grouting, perhaps requiring special surface treatment.
- 51. 2. Joint Width and Continuity The easiest joints to grout have widths in the range between about 0.250 in [6 mm] and 0.020 in [0.5 mm]. Continuity of open jointing systems affects penetration: lack of continuity means that more grout holes will be needed than if grout can travel appreciable distances through the systems.
- 52. 3. Joint Inclination Where dipping is mainly between 20° and about 60°, vertical grout holes may give optimum interception. These are the easiest to drill and are preferable. Steeper jointing usually requires use of inclined holes.
- 53. 4. Uniformity of Site Uniformity of jointing permits a regular layout of grout holes, whereas irregular jointing, dykes, disconformities, and so on may require placement of holes at various inclinations and spacing . Weaknesses may need to be treated intensively.
- 54. 7. Piping Where material in joints can be removed by seepage, either by taking the material into solution or by eroding it, the grouting will need to be more intensive than otherwise in order to ensure that seepage through such joints is virtually eliminated.
- 55. Starting Mix Decided on: • The recommended water:cement ratio is 2 : 1 for starting many of the grouting jobs. This is two parts of water to one part of cement, measured by volume. • However, if the majority of cracks are known to be relatively FINE such as 0.75mm or finer , starting with 3 : 1 could be better. At the other extreme, If cracks are fairly WIDE such as 1.25mm, it is usually wise to start with 1 : 1. (W:C ratio by volume) •
- 56. Fast Grout take If the hole takes grout very rapidly, use of a thicker mix can be warranted, except in the special case where large voids are present; the water test before grouting should have indicated whether such voids are present. Usually, a fast take with minimal pressure buildup indicates that the cracks will probably accept a thicker mix without blocking. Therefore the grout should be thickened by one step and injected into the hole so as to use the thickest practicable grout and thereby gain maximum durability. Further thickening of the mix might be warranted if grout behaviour warrants this.
- 57. STANDARD MIXES and THICKENING STEPS There is no need to use any other mixes than 5 : 1 by volume 4 : 1 3 : 1 2 : 1 1 : 1 0.8 : 1 0.6 : 1 0.5 : 1
- 58. When thickening the mix during grouting, proceed down the list one mix at a time - never jump a mix. For instance, if thickening from 3 : 1, go to 2 : 1 for a while and then to 1 : 1 and perhaps on. Never go straight from 3 : 1 down to 1 : 1 or else the too sudden thickening is liable to prematurely block cracks in the job.
- 59. Procedure and Monitoring of Grouting Operation
- 60. ROCK GROUT CLOSURE WHEN DOING CEMENT GROUTING Closure grouting is the process of drilling and grouting the first holes in an area fairly widely apart, then drilling and grouting a hole midway between them, then putting holes midway in the remaining gaps, and so on, continuing this process of halving centres until enough grouting has been done. The first holes are usually called PRIMARY. The holes midway between them usually are given the name SECONDARY.
- 61. The Concept of Closure
- 62. The Concept of Closure
- 63. When grout holes are longer than about 30 ft [10 m], it is usually best to divide them into shorter lengths, called stages, and grout each of these stages separately.
- 66. UPSTAGE
- 67. PATTERN OF GROUT HOLES FOR CURTAIN GROUTING AND CONSOLIDATION ROCK GROUTING
- 72. As per IS : 6066
- 73. STAND PIPE FITTINGS UPHEAVAL GAUGE FOR EARTHEN DAM UPHEAVAL GAUGE FOR MASONARY / CONRETE DAM
- 75. High take of grout
- 76. TPC Diagrams for behaviour of grout hole
- 77. Refusal Criteria Each grout operation should continue until refusal is reached. Refusal is considered to have been reached when intact grout at the desired limiting pressure is less than 2 lit/min averaged over a period of 10 minutes and the pressure greater than 3.5kg/cm2, or 1 lit/min when the pressure is below 3.5kg/cm2.
- 79. GRAVEL SAND COARSE SILT SILT (NON PLASTIC) FINE COARSE MEDIUM FINE CEMENT BENTONITE POLYURETHANE AND POLYACRYLAMIDE SILICATES – HIGH CONCENTRATION SILICATES – LOW CONCENTRATION AMINOPLAST PHENOPLASTS MICRO FINE CEMENT GROUT ACRYLAMIDE ACRYLATES PENETRABILITY OF GROUTS
- 80. Grout Materials Neat Cement Grouts Cement Grouts with Bentonite Cement Grout with Flyash Cement Grout with Chemical Admixtures Sand Cement Grouts Chemical Grouts Sodium Silicate Lignosulphonate Aminoplast Phenoplast Acrylamide Polyurethane Epoxy
- 81. CEMENT BENTONITE GROUTS Clay H.G. Bentonite Cement Water +Peptizing agent - - 0.5 8 - 0.8 0.2 0.6 6 0.1 to 2% - 0.4 1 5 2% - 0.7 1 5 2% 0.4 0.6 0.6 6 2% - 1 0 8 Sodium silicate Monosodium phosphate - 1 0.5 8 S/ P = 1 =1
- 82. Marsh Cone – Oriffice Type Viscometer Horizontal Flow Meter for Flow measurement of Sand Cement Grout Bleeding Test for Bleeding Potential Mearuement Water Retentivity Testing Set Up
- 83. Penetrability and Washout Test Set Up for Seepage Study through Grouted sample Grout Injection Mould for Strength Measurement
- 86. The basic material should be as follows: A powder readily soluble in water. Inexpensive & derive in abundant supply. Non toxic Non corrosive Non explosive The grout solution should have: A low viscosity solution Stable under all normal temperature Non toxic, non corrosive, non explosive Catalyzed with common inexpensive chemicals Insensitive to salts normally found in ground water Of stable pH Readily controlled for varying gel times Able to withstand appreciable dilution with ground water.
- 87. The end product should be: Permanent gel Unaffected by chemicals normally found in ground water Non toxic, non corrosive, non explosive High strength
- 88. Since about 1970, silicate and acrylamide-based grouts share a market percentage between 85% and 90%, with the remaining portion of the market divided among other products. Chemical grouts fall into the following categories: Silicate formulations Acrylics (includes acrylamide and acrylate grouts) Lignosulfonates Phenoplasts Aminoplasts Other materials Chemical Grout Types
- 90. ELECTROKINETIC GROUTING • Electrokinetic grouting may be applied towards solidification of soil, reducing its permeability and thereby increasing the strength of the soil. – Definition: When a DC current is applied across a sandy soil mass or any fine grained soil, sodium silicate (Na2SiO3) in the cathode compartment and the reactants like calcium chloride (CaCl2) as a hardener in the anode compartment migrate. The anionic silicate will migrate toward the anode due to electro-migration and cationic metal ions will migrate toward the cathode. When these charged ions meet within the soil, the pH of sodium silicate will be reduced and thereby form a gel within the soil and grout the soil mass. In silty soil where electroosmosis (pore water flow from anode to cathode) occurs due to application of D.C. electric field, it is expected that water-soluble sodium silicate grout will be carried away by electroosmotic flow from the anode towards the cathode. When the pH of this grout is reduced by the H+, generated and migrated (Electromigration) from the anode, the sodium silicate grout will form a gel and stabilize the soil.
- 93. • Electrokinetic Grouting may also be used to trap or immobilize the contaminants within their host soil medium instead of removing them through chemical or physical treatment; simultaneously while densifying the soil.
- 94. SOIL TREATED BY ELECTROKINETIC GROUTING • This method, an application of electrokinetic remediation technique, was used to improve the geotechnical properties of the soil mass by using a chemical grout. Soil was compacted in model by hand compaction. • At anode concentration used was made using 2% calcium chloride (CaCl2) powder dissolved in tap water, whereas at the cathode 20%, 25% and 30% sodium silicate (Na2SiO3) dissolved in tap water was used for different tests. • These solutions were used as two different components of a most commonly used chemical grout. • Carbon electrodes were then placed and connected to an AC- DC converter unit.
- 95. Model No. L (cm) H (cm) W (cm) Fill Height (cm) o/p 1 8.3 19.8 10.2 15 o/p 2 18.2 19.5 15.5 15 o/p 3 25 19.8 20 15 o/p 4 41 22 30 15 Different size of open model
- 96. 98 Comparison of initial and final UCS of soil at different locations 0.000 0.200 0.400 0.600 0.800 1.000 1.200 1.400 Anode Middle Cathode UCS in kg/ cm 2 Before Electrokinetic Grouting After Electrokinetic Grouting
- 97. Case Study
- 98. Work at KAKRAPAR Canals in Gujarat At the instructions of the Government of Gujarat, a Study has been taken up by Cemindia, Bombay under World Bank Credit for adopting the method of Grouted Mattress in India. For this purpose pilot testing have been taken up at two sections of Kakrapar Canal system near Surat. The canal has a maximum flow of about 250 cusecs and water depth of about 1.8 meters, having bed of about 6.6 wide and side slopes are 1 vertical to 1.5 horizontal.
- 99. Grouted Geotextile Mattress Preamble As a consequence of research and development jointly by the Applied Mechanics Department & Textile Engineering Department of Faculty of Technology & Engineering and indigenous technique of GROUTED GEOTEXTILE MATTRESS for canal lining under flowing water condition was devised by R & D Division of Cemindia. Model and field studies have revealed that the strength of material in lining attained at 28 days is about 180 kg/cm2 and the permeability and rugosity co-efficient of lined canal are within the limit of code of practice.
- 100. Technique The technique involves use of and mattress cove made with two layers of a specially woven synthetic fabric (Fig.) Strip or threaded spacers are provided in the dual walled fabric which give the mat its characteristics “cobbled” effect. The woven fabric is positioned on the prepared slope or surface and subsequently filled with fine grained sand-cement grout mix. The completed mat provides a slab of nominal 100 mm thickness. Construction of the concrete matting starts with the positioning and securing of the mattress on the ground profile.
- 101. Special pipes are then inserted to the bottom of the frame work. Colloidal sand cement mix is then pumped into position as the pipes are gradually with drawn to the surface. (Fig.) Pumping in this way under low pressure ensures continuity and uniformity of the filter and as the concrete mat is casted, it adapts itself to the ground profile. The mix is normally used for pumping consists of sand, cement and water.
- 102. Mattress fabric cover with spacer A typical fabric developed for this purpose which involves special three dimensional weaving technique. The fabric is a double layered one and the two layers can be separated by a predetermined amount with the help of spacer yarns. The spacer yarn ensures the continuity of the two layers of the fabric shell as well as the thickness of the lining without any hindrance to the fluid flow of the grout mix during its application. The length and distribution of the spacers yarn in total fabric matrix can be manipulated to suit the specific requirements of the lining thickness and grout pressure. To resist the pressure it is essential that fabric shell possess sufficient tensile and bursting strength as also low value of elongation at all levels of loading. The fabric is resistant to acids, alkalis and other common chemical as also to weathering and exposure to sunlight.
- 103. CHARACTERISTICS OF DOUBLE LAYER GEOTEXTILE88 1) Warp – Nylon yarn – Count – 1120 Deniers , Breaking load – 7.36 Kgs. At 10 cms gauge length 2) Weft – Polypropylene flat Tape – Count – 1038 Deniers Breaking load – 3.66 Kgs at 10 cms gauge length %age Elongation – 41.83 % 3) Space Yarn –Nylon woven ape – Count – 7160 Deniers Breaking load – 41.42 Kgs. %age Elongation – 45.10 % No. of ends and picks per inch 22 Two spacer yarns are used.
- 105. The Canal perimeter was cleared of vegetation and trimmed to provide a reasonably working surface. A canal perimeter is about 14.7 m. The mattress length of about 15 m was laid, in the flowing water conditions, on the bed and side slopes of the canal. It was properly secured along the edges. The next length of the mattress was joined to the first 15 m length after completion of the in-filling of the mattress. The joining of bed lengths was carried out in the flowing canal. The mattress was filled up with a pumpable mix of cement- sand – water and additives by the help of screw type pump. The nominal thickness of the lining as achieved in about 11 cm. Tests carried out on samples from the lining itself showed that the strength of the materials attained at 28 days is about 180 kg/cm2.
- 108. Concluding remarks It is essential to have good understanding of the geologic conditions being treated by grouting. The grouting program should be designed to address those conditions and maintain sufficient flexibility to accommodate new information obtained following implementation. “Cook Book Programme” will not suffice. The geologic, grouting and permeability should be continuously monitored so that appropriate changes in the design can be made, and so that the impact of the inevitable geological surprise can be minimized.
- 109. dr_dlshah@yahoo.com