STUDY ON PERMEATION GROUTING IN COARSE GRAINED …

1 International Journal of Pure and Applied Mathematics Volume 119 No. 12 2018, 9289-9300. ISSN: 1314-3395 (on-line version). url: Special Issue STUDY ON PERMEATION GROUTING IN COARSE GRAINED SOIL. WITH CEMENT CHEMICAL GROUT (SODIUM SILICATES). , , Assistant Professor1,2 , Associate Professor3 ,Department of Civil Engineering 1,2,3. BIST, BIHER, Bharath University. ABSTRACT. GROUTING is the process of ground improvement techniques which is used to improvise the foundation where there is loose state of the soil. GROUTING can be classified as PERMEATION GROUTING , compaction GROUTING or hydraulic fracturing. PERMEATION GROUTING is an effective way to send the grout into the ground without disturbing the soil structure. In this investigation, an attempt is made to STUDY the effect of cement grout with (sodium silicate) in improving the bearing capacity of the sandy soil.

2 Cement grout with different ratio of 10:1 ( Water: Cement) , 8:1, 6:1, 4:1 are injected into the soil. GROUTING experiment is performed with perforated PVC. pipe in a tank of 50cm x 50cm x 50cm sandy soil. To STUDY the improvement in the strength property of the grouted soil the plate load test is performed with 14cm x 14cm plate on the grouted sand after 7days curing and 28 days curing and this STUDY revealed that the increase in cement content increases load carrying capacity of the sandy soil. INTRODUCTION. The term Ground improvement and ground modification refers to any procedure undertaken to increase the shear strength, decrease the permeability and compressibility or otherwise render the physical properties of soil more suitable for projected engineering use.

3 The constructional activities in the coastal belt of our country often demand deep foundations because of the poor engineering properties and the related problems arising from weak soil at shallow depths[7-12]. The soil profile in coastal area often consists of very loose sandy soils extending to a depth of 3 to 4 m from the ground level underlain by clayey soils of medium stiffness. The structures built on such soils may suffer from excessive settlements and would lead to punching shear failure. GROUTING is the suitable technique in improving the weak soil. GROUTING technique finds applications in case of seepage control in rock and soil under dams, advancing tunnels, cut off walls etc (Nonveiller, 1989). The main purpose of GROUTING is to fill the voids of the formation material by replacing the existing fluids with the grout and thereby improving the engineering properties of the medium, especially reducing the permeability[1-6].

4 Over the past years, many types of chemicals have been used for geotechnical applications. But generally chemical grouts are toxic and hazardous in nature. This necessitates the need to do research in finding alternate ecofriendly materials for ground improvement. It seems that many chemical admixturer can be used as substitute for conventional components of GROUTING materials. Hence in this STUDY an attempt is made to use the soidium silicate as an additive with the cement grout to STUDY the improvement of the soil property. Hamid Reza Khatami et al[13-19]., has concluded that, biopolymers can effectively improve the strength 9289. International Journal of Pure and Applied Mathematics Special Issue characteristics of sand without causing environmental toxicity.

5 Laetitia Patural et al., has conclude that, cellulose are thickener, good binder, film former and used as additives to improve the cement based material and also improve the properties of mortar such as water retention, workability, and consistency of material. P. Dayakar et al., conclude that, PERMEATION GROUTING is an effective way to send the grout into the ground without disturbing the soil structure. The increase in cement content increases load carrying capacity of the sandy soil[20-26]. MATERIALS. Materials involved in GROUTING process are soil and grout materials. In this STUDY the grout materials are cement with sodium silicate which is termed as chemical grout. % Finer Particle size dia, mm (log). Grain Size Distribution of Soil Locally available Palar river sand is utilized for this STUDY and the properties of the sand are given in table 1.

6 The grain size distribution curve of the soil used is shown in From the grain size distribution curve the Coefficient of curvature (Cc) and Coefficient of uniformity (Cu). are calculated and tabled in table Also the other properties such as the Specific gravity, maximum and minimum void ratio are also calculated and given in the table[27-32]. Table1 Properties of sand Specific Gravity, G D , mm 60. D , mm 30. D , mm 10. C c C u e max e min 9290. International Journal of Pure and Applied Mathematics Special Issue Ordinary Portland Cement (OPC). Ordinary Portland cement is new geneSpecimenn cement. It contains high reactive Silica (HRS) to enhance ultimate performance of concrete. OPC is essentially a siliceous material in finely divided form with the presence of water, that react with Calcium hydroxide at ordinary temperature liberated during the hydSpecimenn of Portland Cement to produce stable,cementations compounds.

7 These compounds contribute to strength and water tightness of Cement and are especially suitable for Dams and mass construction like foundation. Table2 Properties of cement ROPERTIES VALUES. Grade OPC. Specific Gravity Fineness, % 95. Consistency, % 35. Initial Setting Time, min 30. METHODOLOGY. GROUTING PERMEATION GROUTING of sandy soil with cement grout of sodium silicates is done in anacrylic tank ( 50cm x 50cm x 50cm ) in room temperature of 28 tank should be completely dry before filling the sand ( ) water content should be there. One-third of the tank is filled with sand. Then the grout pipe is placed in the tank in manner of dividing it four parts and place it in the centre of each parts. Thin film foils should place inside the pipe such that the sand should not enter the grout pipe's holes.

8 Then the soil is filled in the tank without disturbing all the four grout pipes. The paper foils are removed from the grout pipes and the mixture of water, cement and sodium silicates is poured inside all four grout pipes equally. The mixture will flow easily into the soils particles. After the grout is filling into the sandy soil in the tank. The grout pipes are removed from the tank gently without disturbing the sand. The gap of the grout pipes is filled with sand[33-37]. Plate Load Setup These apparatuses consist of three units, as shown in the figure Cell pressure unit, the back pressure unit and the triaxial cell. The cell pressure unit and back pressure unit regulate the corresponding pressure with a piston system, The sample ( , grouted soil acrylic tank 50cm X.)

9 50cm X 50cm ) in the is placed in the triaxial cell and the axial load is applied to the sample through the plate place at center, via the load cell and the loading frame. The plate is place on the loading frame so that extension tests can be performed easily. In addition, a gear box is installed, which reduces the vertical movement. The axial displacements are measured the cell by the external Linear Variable Displacement Transformer (LVDT), which is mounted above solid part of the tank and analyzing the displacement measurement devices with respect to their accuracy, the following errors are recognizable. In the axial direction, the LVDT is mounted above the solid part of the acrylic tank and measures down to the bottom of the pedestal[38-42]. 9291. International Journal of Pure and Applied Mathematics Special Issue Figure 1 Triaxial loading machine Plate load test The sample is placed in triaxial loading machine, and a steel plate (14x14cm) is placed at the top centre as shown in Figure A steel spherical ball is placed over the centre of the loading test plate[43-47].

10 A load cell as shown in Figure is placed over the spherical steel ball, in order to take the reading of the load which applied. The LVDT (Linear Variable Differential Transformer). Figure 2 Load cell arrangements. Figure 3 LVDT. 9292. International Journal of Pure and Applied Mathematics Special Issue Figure 4 Data logger RESULTS & DISSCUSION. GROUTING Results We have taken the readings of the grouted sand after 7 days and another set after 28 days. The7 days and 28 days test are taken in different water cement Specimen such as 10:1, 8:1, 6:1, and 4:1 respectively. The readings are taken with the help of data logger[48-50], LVDT and lode cell. A graph is plotted displacement due to load and load applied on the grouted soil. The tabulation of the 7 day tested samples which is in loose state is from the table Similarly for the seventh day loose state is furnished in the table and comparison of this test are compared in graph in figure and figure for the medium dense state grouted soil was tested and the results are in the table to table Graphs are plot in figure and figure In the graph (figure , , and ) we have given some notation as follows load intensity kN/m2.