Lab Manual for Soil Testing

JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERINGLaboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Table of Content Sr. No. Title Date Page No. Sign Remark JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. ___ Date: Name of Experiment: Determination of Specific Gravity of Fine Grained Soils Aim:To determine the specific gravity of fine-grained soil by density bottle method as per IS: 2720 (Part III/Sec 1) - 1980. Scope:This experiment lays down the methods of test for the determination of the, specific gravity of soil particle of fine grained soils. The method may also be used for medium and coarse grained soils if the coarse particles are grained to pass 4.75 mm sieve before using. Principle:Specific gravity is the ratio of the weight in air of a given volume of a material at a standard temperature to the weight in air of an equal volume of distilled water at the same stated temperature. Apparatus: a. Two density bottles of approximately 50ml capacity alongwith stoppers, b. Constant temperature water bath (27 +0.20C), c. Oven, capable of maintaining a temperature of 105 to 1100C, d. Weighing balance, with an accuracy of 0.001g, e. Wash Bottle f. Spatula Sample Preparation: The soil sample (50g) should, if necessary, be ground to pass through a 2 mm IS Sieve. A 5 to 10g sub-sample should be obtained by riffling and oven-dried at a temperature of 105 to 1100C. Page 1 of 59 JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Procedure: a. The density bottle along with the stopper, should be dried at a temperature of 105 to 1100C, cooled and weighed to the nearest 0.001g (m1). b. The sub-sample, which had been oven-dried, should be transferred to the density bottle directly. The bottles and contents together with the stopper should be weighed to the nearest 0.001g (m2). c. Cover the soil with air-free distilled water from the wash bottle and leave for a period of 2 to 3hrs for soaking. Add water to fill the bottle to about half. d. Entrapped air can be removed by heating the density bottle on a water bath until there is no further loss of air. e. Gently stir the soil in the density bottle and see that no soil particles are lost. f. Repeat the process till no more air bubbles are observed in the soil-water mixture. g. Observe the constant temperature in the bottle and record. h. Insert the stopper in the density bottle, wipe and weigh (m3). i. Now empty the bottle, clean thoroughly and fill the density bottle with distilled water at the same temperature. Insert the stopper in the bottle, wipe dry from the outside and weigh (m4). j. Take at least two such observations for the same soil sample. Observations and Calculations: Sr. No. Description 1. Weight of density bottle (m1) (gm) 2. Weight of bottle and dry soil (m2) (gm) 3. Weight of bottle, dry soil and Water (m3) (gm) 4. Weight of bottle and Water (m4) (gm) Sample – 1 Sample – 2 Sample – 3 5. 6. Average Specific Gravity Page 2 of 59 If the room temperature is different from 270C..01. Specific gravity of the given soil sample at a temperature of 270C = Relative density of water at various temperatures.JSPM-NTC. b. as given below.03 the teats shall be repeated. The average of the values obtained shall be taken as the specific gravity of the soil particles and shall be reported to the nearest 0. can be used in the above calculation: Result: Specific Gravity of given Soil sample is ……. If the two results differ by more than 0. Page 3 of 59 . DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Reporting of Result: a. The specific gravity should be calculated at a temperature of 270C. the following correction should be done:G' = k * G Where. G' = Corrected specific gravity at 270C. 2mm. 4. dry sieving. Apparatus: a. down to fine sand size. c. Scope:Thisexperiment lays down the methods of test for the determination of thegrain size distribution in soil passing 4.75mm. wet sieving shall be applicable to all soils and the second.36 mm 2. Hot air oven d.00 mm 1. A set of IS Sieves of sizes . The combined silt clay can be obtained by difference. the first method. 425μm. Weighing balance. 10mm. Mechanical sieve shaker LID 4. with an accuracy of 0. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No.75 mm 2. If the soil Page 4 of 59 .1985.JSPM-NTC.75mm IS sieve and retained on 75-micron IS sieve. 212μm and 75μm b.001 gm. ___ Date: Name of Experiment:Sieve analysis. Current experiment details the dry sieving method.70 mm 600 425 300 150 75 PAN SIEVE SHAKER Principle:This method covers the quantitative determination of particle size distribution in an essentially cohesionless soil. Two methods are given for finding the distribution of grain sizes larger than 75-micron IS Sieve. Aim:To determine the quantitative determination of grain size distribution in soils by sieve analysis as per IS: 2720 (Part 4) . shall be applicable only to soils which do not have an appreciable amount of clay. 600μm.20mm. particle size determination and IS classification as per ISCodes. Page 5 of 59 . A representative soil sample of required quantity as given below is taken and dried in the oven at 105 to 1200C. Sample Preparation: a. d.5 3. should be dried in air or in the sun.75-mm IS Sieve shall be taken separately for the analysis.5 1. Soil retained on each sieve is weighed. While sieving through each sieve.5 0. The sample shall be separated into various fractions by sieving through the Indian Standard Sieves as specified in the figure. c.5 10 6. thehydrometer method shall be used. The portion of the soil sample retained on 4. The clod may be broken with wooden mallet to hasten drying.JSPM-NTC.75 0. The soil fractions retained on and passing 4.75 Weight to be taken for test (kg) 60 25 13 6. Maximum size of material present in substantial quantities (mm) 75 40 25 19 12. the sieve shall be agitated so that the sample rolls in irregular motion over the sieve. b. The big clods may be broken with the help of wooden mallet. oven may be used in which case the temperature of the sample should not exceed 600C. c.75-mm IS Sieve shall be weighed and the mass shall be recorded. In wet weather. Soil sample. Tree roots and pieces of bark should be removed from the sample. Any particles may be tested to see if they will fall through but they shall not be pushed through. Care should be taken not to break the individual soil particles. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course does not contain particles retained on a 2 mm test sieve in significant quantity. b.5 4. as received from the field.4 Procedure: a. e. 4. 1. 0.150 9. Weight of total Soil sample taken for analysis: …………… gm Sr.00 4.70 5.JSPM-NTC. IS Classification of the soilsample: Based on the grain size distribution curve plotted on a semi-logarithmic chart. calculate following: D10 = 10 percent finer than size = ………… D30 = 30 percent finer than size = ………… D60 = 60 percent finer than size = ………… Cu = Cc = Page 6 of 59 .75 2. Sieve Size(A) Weight Retained(B) Cumulative Weight(C) (mm) (gm) (gm) 1.075 % Weight retained(D) % Weight passing(100D) Reporting of Result: A grain size distribution curve shall be drawn on a semi-logarithmic chart. all the observations shall be recorded in the tabular as given below to calculate percentage smaller than the specified diameter. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Observations: After completing mechanical analysis. 0.600 6. 0. plotting particle size (sieve diameter) on the log scale (X-axis) against percentage finer than the corresponding size (% weight passing) on the ordinary scale (Y-axis).36 3. 2. 0. 0.300 8. 2.425 7. No. Page 7 of 59 . following procedure shall be adopted for classification of given sample based on grain size distribution curve: If more than 50% sample retained on 2..36mmIS sieve: If 5% and less is passing through 75µ sieve If Cu>=4 AND Cc<=3 Then soil can be classified as ‘GW’ If Cu<7 OR Cc>3 Then soil can be classified as ‘GP’ If 5% to 12%is passing through 75µ sieve Then use dual symbols If 12% and more is passing through 75µ sieve Then Conduct Limit tests and then classify If more than 50% sample passing through 2.36mm sieve: If 5% and less is passing through 75µ sieve If Cu>=6 AND Cc<=3 Then soil can be classified as ‘SW’ If Cu<6 OR Cc>3 Then soil can be classified as ‘SP’ If 5% to 12% is passing through 75µ sieve Then use dual symbols If 12% and more is passing through 75µ sieve Then Conduct Limit tests and then classify Result:IS Classification of given Soil sample is …….JSPM-NTC. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course As per IS 1498. JSPM-NTC. Theory and Principle: The consistency of a fine grained soil is the physical state in which it exists. It is used to denote the degree of firmness of a soil. Variations in the moisture content in a soil may have significant effect on its shear strength. Atterberg. viz. mentioned that a fine grained soil can exist in four states. plastic. In 1911. Page 8 of 59 . Scope: Thisexperiment lays down the methods of test for the determination of Consistency limits of fine grained cohesive soil. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. Consistency of a soil is indicated by terms as soft. firm or hard. Soil consistency provides a means of describing the degree and kind of cohesion and adhesion between the soil particles as related to the resistance of the soil to deform. a Swedish engineer. especially on fine-grained soils. ___ Date: Name of Experiment:Determination of Consistency limits and their use in soil classification as per IS Codes Aim: To determine the Consistency limits of fine grained soils as per IS: 2720 (Part 5) . The water contents at which the soil changes from one state to the other are known as ‘Consistency limits’ or ‘Atterberg’s Limits’. liquid.1985. semi-solid or solid state. Grooving tools of both standard and ASTM types c. the soil becomes stiffer and starts developing resistance to shear deformation. Air-tight and non-corrodible container for determination of moisture content Casagrande Grooving Tool ASTM Grooving Tool Page 9 of 59 . therefore. As the water content is reduced. Spatula e. The water content at which the soil changes from liquid state to plastic state is known as ‘Liquid Limit’. In other words. the soil becomes plastic. Weighing balance. Apparatus: a. Casagrande’s liquid limit device b. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course A. with 0. At some particular water content. IS Sieve of size 425μm f.01g accuracy g. the liquid limit is the water content at which the soil ceases to be liquid. It offers no shearing resistance and can flow like liquids. the shear strength is equal to zero. It has no resistance to shear deformation and. Hot air Oven d. Liquid Limit: A soil containing high water content is in a liquid state.JSPM-NTC. i. Water content corresponding to 25 blows. etc. b. For normal fine grained soil: The Casagrande's tool is used to cut a groove 2mm wide at the bottom. e. is the value of the liquid limit. Draw the grooving tool through the sample along the symmetrical axis of the cup. b. Remove the organic matter like tree roots. h. with no. About 100g of the specimen passing through 425μm IS Sieve is mixed thoroughly with distilled water in the evaporating dish and left for 24hrs for soaking. g. Liquid limit is determined by plotting a ‘flow curve’ on a semi-log graph. Don’t mix dry soil to change its consistency. obtain at least 5 readings in the range of 15 to 35 blows. 13. till the two parts of the soil sample come into contact for about 10mm length. Page 10 of 59 . Repeat the test. By altering the water content of the soil and repeating the foregoing operations.6mm wide at the top and 10mm deep. j. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Sample Preparation: a. The soil of the cup is transferred to the soil paste and mixed thoroughly after adding a little more water.JSPM-NTC. Level the mix so as to have a maximum depth of 1cm. After the soil pat has been cut by a proper grooving tool. Place a portion of the paste in the cup of the liquid limit device. the handle is rotated at the rate of about 2 revolutions per second and the no. d. f. Air-dry the soil sample and break the clods. c. k. Take about 10g of soil near the closed groove and determine its water content. of blows as abscissa (log scale) and the water content as ordinate and drawing the best straight line through the plotted points. of blows counted. Procedure: a. holding the tool perpendicular to the cup. 11mm wide at the top and 8mm deep. For sandy soil: The ASTM tool is used to cut a groove 2mm wide at the bottom. pieces of bark. %. Mass of empty dish + wet soil (m2) (gm) 5. Draw a flow curve on a semi-log paper between log (N) on X-axis and water content on Y-axis. Page 11 of 59 . Mass of empty dish (m1) (gm) 4. Mass of dry soil = (m3 – m1) 8. of Blows (N) 2. No. Mass of empty dish + dry soil (m3) (gm) Calculations 6. No. 3. Mass of water = (m2 – m3) 7. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Observations: Sample No.JSPM-NTC. Sr. Result:Liquid Limit (for N=25) of given Soil sample is ……. Descriptions 1 2 3 4 5 Observations 1.. Water Content Dish No. Water Content. Ground glass plate .01g d. Spatula b. Hot air Oven e. without any cracks appearing. Procedure: a. The rate of rolling should be between 80 to 90 strokes per minute to form a 3mm dia. Apparatus: a. Balance. Rod . This period may be up to 24hrs. Take about 8gm of the soil and roll it with fingers on a glass plate. it means that the water content is more than its plastic limit.JSPM-NTC. with an accuracy of 0. c. Mix the soil with distilled water in an evaporating dish and leave the soil mass for nurturing. If the dia. Page 12 of 59 .3mm dia. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course B. Plastic Limit: The plastic limit of fine-grained soil is the water content of the soil below which it ceases to be plastic. and about 10cm long Sample preparation: Take out 30g of air-dried soil from a thoroughly mixed sample of the soil passing through 425μm IS Sieve. b.20cm x 15cm f. It begins to crumble when rolled into threads of 3mm diameter. Container to determine moisture content c. of the threads can be reduced to less than 3mm. Repeat the process of alternate rolling and kneading until the thread crumbles. Knead the soil to reduce the water content and roll it into a thread again. e. Plasticity Index = (Liquid Limit) – (Plastic Limit) Plasticity Index (PI) = ………. Observations: Sample No. Mass of water = (m2 – m3) 6. Collect and keep the pieces of crumbled soil thread in the container used to determine the moisture content. Mass of empty dish + dry soil (m3) (gm) Calculations 5. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course d. 8. Average % water content Result: Plastic Limit of given Soil sample is ……. Water Content. No.JSPM-NTC. Water Content Dish No. Mass of empty dish (m1) (gm) 3. Mass of dry soil = (m3 – m1) 7.. Descriptions 1 2 3 4 5 Observations 1. 2. Mass of empty dish + wet soil (m2) (gm) 4. Repeat the process at least twice more with fresh samples of plastic soil each time. Sr. % IS Classification: The fine-grained soils shall be further divided into three subdivisions on the basis of the following arbitrarily selected values of liquid limit: Page 13 of 59 .%. Silts and clays of medium compressibility — having a liquid limit greater than 35 and less than 50. c.JSPM-NTC. b.. Silts and clays of low compressibility — having a liquid limit less than 35. Page 14 of 59 . Silts and clays of high compressibility — having a liquid limit greater than 50. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course a. The laboratoryclassification criteria for classifying the fine-grained soils are given in the plasticity chart as given below: Result: IS Classification of given Soil sample is ……. the soil will continue to decrease in volume. sufficient to fill the glass cup to overflowing. and material for the test could therefore conveniently be prepared as part of the Liquid Limit test.01 gm j. originally having the moisture content of the Liquid Limit. Sample Preparation: This test commonly is performed as a continuance of the Liquid Limit and Plastic Limit tests. i. Straight edge. If the drying process is prolonged after the plastic limit has been reached. Measuring cylinder. Plain plate. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course C. c. Such a value is also relevant to the converse condition of expansion due to wetting. glass cup. b. but less significant in silts and sands. Mercury — clean. d. Apparatus: a. The Linear Shrinkage value is a way of quantifying the amount of shrinkage likely to be experienced by clayey material. which is also relevant to the converse condition of expansion due to wetting. e. f. g. 425-micron IS Sieves. Prong plate.JSPM-NTC. Shrinkage Limit: Shrinkage due to drying is significant in clays. Spatula. Page 15 of 59 .Linear Shrinkage method covers the determination of the total linear shrinkage from linear measurements on a soil sample passing a 425 m test sieve.1 g and 0. Shrinkage dish. Hot air Oven h. Balances — sensitive to 0. JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Otherwise a 150 g sample should be prepared in the same way as specified for the Liquid Limit test. A sample of material passing through a 425-micron sieve shall be thoroughly mixed with distilled water until the mass becomes a smooth homogeneous paste with moisture content at about the Liquid Limit of the soil. Procedure: a. Take the shrinkage dish. Clean it and determine its mass. b. Fill mercury in the shrinkage dish. Remove excess mercury by pressing the plain glass plate over the top of shrinkage dish. c. Transfer the mercury from shrinkage dish to mercury weighing dish and determine the mass of the mercury to an accuracy of 0.01gm. The volume of shrinkage dish (V1) is equal to the mass of mercury in grams divided by the specific gravity of mercury (i.e. 13.6). d. Coat the inside of the shrinkage dish with wax or grease or Vaseline. e. Place the soil specimen in the center of the shrinkage dish equal to one third the volume of the shrinkage dish. Tap the shrinkage dish on a firm surface and allow the paste to flow to the edges. f. Repeat the process till getting full level of shrinkage dish. g. Wipe off all soil adhering to the outside of the shrinkage dish. Determine the mass of wet soil (m1). h. Dry the soil in shrinkage dish in air till the color of the pat turns from dark to light. Then dry the pat in the oven at 105 – 1100C to constant mass. i. After cooling the dry pat, weigh the shrinkage dish with dry pat to find the dry mass of soil (m2). j. Place a glass cup in an evaporating dish and fill it with mercury. Remove excess mercury by pressing prong plate over the top of glass cup. k. Remove the glass cup with full of mercury and place it in another evaporating dish with spilling any mercury from the glass cup. l. Take out the dry pat of the soil from shrinkage dish and immerse in the glass cup full mercury. Press prong plate on the top of cup firmly allowing spilling of mercury in the evaporating dish. m. Collect the mercury displaced by dry pat in mercury weighing dish. Determine the mass of mercury to an accuracy of 0.01gm. n. The volume of the dry pat (V2) is equal to the mass of the mercury divided by the specific gravity of the mercury. o. Repeat the above test procedure for atleast 3 samples. Page 16 of 59 JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Observations: Sample No. Sr. No. Descriptions 1 2 3 Observations 1. Mass of empty mercury dish (gm) 2. Mass of empty mercury dish + Mercuryequal to volume of shrinkage dish (gm) 3. Mass of Mercury (gm) = (2-1) 4. Volume of Shrinkage dish, 5. Mass of Empty shrinkage dish (gm) 6. Mass of Empty shrinkage dish + Wet soil (gm) 7. Mass of Wet soil (M1) = (6-5) 8. Mass of Empty shrinkage dish + Dry soil (gm) 9. Mass of Dry soil (Ms) = (8 – 5) 10. Mass of empty mercury dish + Mercury equal to volume of Dry pat (gm) 11. Mass of Mercury displaced by Dry pat (gm) = (10 - 1) 12. Volume of Dry pat, Calculations 13. Shrinkage limit, 14. Shrinkage Ratio, 15. Volumetric Shrinkage, Result:Average Shrinkage Limit of given Soil sample is ……..%. Page 17 of 59 JSPM-NTC, DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. ___ Date: Name of Experiment:Determination of Field Density Aim: To determine the in-situ dry density of soil by various methods (i) core cutter method and (ii) Sand replacement method as per IS: 2720 (Part XXIX - 1975 and Part XXVIII – 1974). Scope: Experiment viz. Field Density by core cutter method covers the method for the determination of the in-place density of fine-grained natural or compacted soils free from aggregates using a core-cutter. For the purpose of the test, a soil shall be termed as fine-grained soil if not less than 90 percent passes through 4.75mm IS Sieve. Determination of field density of cohesionless soil is not possible by core cutter method, because it is not possible to obtain a core sample. In such situation, the sand replacement method is employed to determine the dry density. Sand Replacement method covers the determination of the dry density of natural or compacted fine- and medium-grained soils for which a small sand pouring cylinder is used. The method is applicable to layers not exceeding 150 mm in thickness. With granular material having little or no cohesion, particularly when they are wet, there is a danger of errors in the measurement of dry density by this method.These errors are caused by the slumping of the sides of the excavated density hole and always result in an over-estimation of the density. Theory:The in situ density of natural soil is needed for the determination of bearing capacity of soils, for the purpose of stability analysis of slopes, for the determination of pressures on underlying strata for the calculation of settlement and the design of underground structures. It is very quality control test, where compaction is required, in the cases like embankment and pavement construction. By conducting field density test by either method, it is possible to determine the field density of the soil. The moisture content is likely to vary from time to time and hence the field density also. So it is required to report the test result in terms of dry density. The relationship that can be established between the dry density with known moisture content is as follows: Where, d = Dry Density; b = Bulk Density; w = Water Content Page 18 of 59 JSPM-NTC.25mm. Apparatus: a.01gm. Steel rule f. Balance e. Page 19 of 59 . Determine the internal diameter and height of the core cutter to the nearest 0. Cylindrical core cutter b. including unit weights. cannot be maintained in a core sample. Determine the mass (M1) of the cutter to the nearest 0. Field Density by Core Cutter Method Core cutter method of determining the field density of soil is only suitable for fine grained soil (Silts and clay). Level the surface. Steel dolley d. c. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course A. This is because collection of undisturbed soil sample from a coarse grained soil is difficult and hence the field properties. Spade or pickaxe g. Steel rammer c. about 300mm2 in area. Expose a small area of the soil to be tested. Knife Procedure: a. b. Straight edge h. Take a representative sample for the water content determination.JSPM-NTC. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course d.gm/cm3. h. Determination of Water Content: a. Weight of Core Cutter + Field Soil (gm) (M2) 6. Weigh the core cutter filled with the soil to the nearest gram (M2). g. Internal Diameter of Core Cutter (d) (mm) 2. Remove the soil surrounding the core cutter. Trim the tip and bottom surface of the core cutter carefully using a straight edge. Bulk Density of soil (gm/cm3) 7. Sample No. f. Determine the water content. 4. b. Average Dry Density (gm/cm3) 2 3 Result:Average Field Dry Density of Soil is ……. Weight of Container (gm) (W1) c. Internal Height of Core Cutter (h) (mm) 3. Remove the core of the soil from the cutter. Stop the pressing when about 15mm of the dolley protrudes above the soil surface. Weight of Container + Wet Soil (gm) (W2) d. Moisture Content. f. Water Content Container No. Page 20 of 59 . Weight of Container + Dry Soil (gm) (W3) e. Dry Density of soil (gm/cm3) 8. Description 1 1. Place the dolley over the top of the core cutter and press the core cutter into the soil mass using the rammer. and take out the core cutter. Weight of Core Cutter (gm) (M1) 5.. Remove the dolley. Observations: Sr. Soil would project from the lower end of the cutter. i. Volume of Core Cutter (mm3). e. No. Sand pouring cylinder b. Glass plate h. Measure the internal dimensions (diameter. Metal tray with a central hole d. with an accuracy of 0. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course B. Standard sand (passing through 600 micron sieve) e. Calibration of the Cylinder i.01gm f. Weighing balance. Field Density by Sand Replacement Method The basic principle of sand replacement method is to measure the in-situ volume of hole from which the material was excavated from the weight of sand with known density filling in the hole. Moisture content bins g. The in-situ density of material is given by the weight of the excavated material divided by the in-situ volume. Calibrating can c. Metal tray i. Scraper tool Procedure: a. V = πd2h/4.JSPM-NTC. Apparatus: a. d and height. Page 21 of 59 . h) of the calibrating can and compute its internal volume. xi. b. Open the slit to allow the sand to run down until the sand flow stops by itself. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course ii. Place the tray with a central hole over the portion of the soil to be tested. close the slit. as this will result in lower density being recorded. before placing the sand pouring cylinder over the pit. so that it is not enlarged by levering. Measurement of Soil Density i. Care should be taken in excavating the pit. Place the sand pouring cylinder. Determine the moisture content of the excavated soil. Now close the slit and find the weight of the sand pouring cylinder with the remaining sand (W3). ix. Excavate a pit into the ground. the standard calibrating can should be replaced by one with an internal height same as the depth of pit to be made in the ground. through the hole in the plate. It should not be forgotten to remove the tray. Find the weight of the sand pouring cylinder along with the sand remaining after filling the cone (W2) v. If for any reason it is necessary to excavate the pit to a depth other than 12 cm. approximately 12 cm deep (same as the height of the calibrating can). No loose material should be left in the pit. Find the weight of the sand pouring cylinder with the remaining sand (W4). Clean and level the ground surface where the field density is to be determined. iv. ii. When there is no further downward movement of sand in the sand pouring cylinder. Collect the excavated soil into the tray and weigh the soil (W). iii. Place the sand pouring cylinder on a glass plate. This operation will fill the calibrating can and the conical portion of the sand pouring cylinder. viii. over the pit so that the base of the cylinder covers the pit concentrically. The sand will freely run down till it fills the conical portion. vi. vii. Open the slit of the sand pouring cylinder and allow the sand to run into the pit freely.JSPM-NTC. iii. Page 22 of 59 . with sand having the latest weight of W3. The hole in the tray will guide the diameter of the pit to be made in the ground. till there is no downward movement of sand level in the sand pouring cylinder and then close the slit. iv. Place the sand pouring cylinder concentrically on top of the calibrating can. v. Fill the sand pouring cylinder with sand with 10mm top clearance (to avoid any spillover during operation) and find its weight (W1). x. open the slit above the cone by operating the valve and allow the sand to run down. Volume of sand required to fill the pit Vp=Wp/γsand (cm3) 15. Weight of sand in the pit Wp = (W3-W4)-Wc (gm) 14. 18. W4 (gm) (After filling the hole & conical portion) Weight of sand in the hole and cone (W3-W4) (gm) 13. Trial No. 4.JSPM-NTC. Weight of sand in calibrating can = Wcc-Wc (gm) 10. Page 23 of 59 . W3 (gm) (After filling calibrating can).. Determination of Field Density of Soil Weight of sand pouring cylinder. W2 (gm) (After filling conical portion on a flat surface). 1 2 Determination of Water Content 17. Wc = W1-W2 (gm) 8. Internal Height of calibrating container (h) (cm) 3. Weight of sand required to fill cone. Weight of sand pouring cylinder + sand. W1 (gm) Weight of sand pouring cylinder + sand. Volume of calibrating container (cm3). Description 1. γsand = (Wcc-Wc)/V (gm/cm3) 11. Weight of Container + Wet Soil (gm) (M2) 20. Calibration of the Cylinder Internal Diameter of calibrating container (d) (cm) 2. No. 22. 12. Weight of Container (gm) (M1) 19. Moisture Content. Water Content Container No. Dry unit weight of the soil γdry=γwet/(1+w) (gm/cm3) Result: Average Field Dry Density of Soil is ……. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Observations: Sr. 6. Weight of sand pouring cylinder + sand. Weight of the excavated soil from the pit (W) (gm) 16. Unit weight of sand. Weight of sand required to fill cone & can Wcc=W2-W3 (gm) 9. Weight of Container + Dry Soil (gm) (M3) 21. 7. Wet unit weight of the soil γwet=W/Vp (gm/cm3) 5.gm/cm3. The coefficient of permeability is equal to the rate of flow of water through a unit cross-sectional area under a unit hydraulic gradient. L = Length of specimen. h = Head causing flow. In the constant head permeameter. Q = Total volume of water. The coefficient of permeability (k) is obtained from the relation: Where. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. settlement etc. In an impervious soil. Theory:The rate of flow under laminar flow conditions through a unit cross sectional area of soil medium under unit hydraulic gradient is defined as coefficient of permeability. Scope: The knowledge of coefficient of permeability is much useful in solving problems involving yield of water bearing strata. A soil is termed impervious when the permeability is extremely low. and embankments of canal bank affected by seepage. stability of earthen dams. ___ Date: Name of Experiment: Determination of coefficient of permeability.JSPM-NTC. This experiment covers the methods for laboratory determination of coefficient of permeability of soils using falling head and the constant head methods as per the procedure mentioned in IS 2720-Part XVII. A soil is highly pervious when water can flow through it easily. The permeability is the ease with which water can easily flow through soil medium. the head causing flow through the specimen remains constant throughout the test. such completely impervious soils do not exist in nature. as all the soils are pervious to some degree. However. q = Discharge. Aim: To determine the coefficient of permeability of a soil using constant head method and variable head method. seepage through earthen dams. A completely impervious soil does not permit the water to flow through it. t = Time period. the permeability is very low and water cannot easily flow through it. A = Cross sectional area Page 24 of 59 . JSPM-NTC. Measuring scale. g. Page 25 of 59 . c. Constant Head Test set-up Variable Head Test set-up Preparation of Sample: a. Stop watch etc. Constant Head Tank d. Compaction Rammer. Coefficient of permeability by Constant Head Method The coefficient of permeability of a relatively more permeable soil can be determined in a laboratory by the constant head permeability test. A 2. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course A. Mix the soil thoroughly. Add water to bring the test specimen. mixing pan. Graduated cylinder. b. c. The permeability mould assembly (including drainage base and drainage cap). to slightly below the apparent optimum moisture content or sufficient water to assure good compaction. e. Apparatus: a.5 kg sample shall be taken from a thoroughly mixed oven dried material. b. f. (i) = (K/L) = …………. Place the mould with sample in the permeameter. Repeat three times for the same interval. Height of Specimen (L) = ………… cm Hydraulic Gradient. g. Average Permeability (cm/sec) Page 26 of 59 . After greasing the inside slightly. Procedure: a. e. Place the assembly on a solid base and fill it with sample in three layers and compact each layer thoroughly. For the constant head arrangement. b. Establish steady flow of water. Weigh the empty permeameter mould. c. Time Elapsed (t) (Seconds) 2. Find the weight of mould with sample. Now the specimen is ready for the test. e. the specimen shall be connected through the top inlet to the constant head reservoir. 4. 3. Description 1. with drainage base and cap having saturated porous stones. Water temperature = ………0C Cross Section area of the specimen/mould (A) = …………… cm2 Sr. After completion of a compaction the collar and excess soil are removed. i. f. The quantity of flow for a convenient time interval may be collected. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course d. Open the bottom outlet. Observations and Calculations: Head of Water (H) = ………… cm. d. h. No. clamp it between the compaction base plate and extension collar. Discharge collected (Q) (cm3) Trial-1 Trial-2 Trial-3 Trial-4 Trial-5 Permeability (cm/sec).JSPM-NTC. cm/sec = …….00874 0.00801 0.006569 0.007568 0.00894 0. The coefficient of permeability is standardized at 270C. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Result: The viscosity of the water changes with temperature.m/sec Page 27 of 59 .. As temperature increases viscosity decreases and the permeability increases. Temperature (0C) 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Viscosity (Poise) 0.00818 0.006369 0..00981 0. From the following table obtain the viscosities and compute K27.006169 0.00936 0.007368 0. k27 = Permeability at 270C T and 27 = Coefficient of water viscosities at the temperature 'T' and at 270C respectively.00597 Average Coefficient of Permeability of Soil is …….01005 0.006969 0.JSPM-NTC.006769 0.00958 0. and the permeability at any temperature ‘T’ is related to K27 by the following ratio: Where.00836 0.00855 0.007768 0.007169 0.00914 0. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course B. the soil sample is saturated and the standpipes are filled with de-aired water to a given level. Take 800 to 1000 gm of representative soil and mix it with water to get optimum moisture content (OMC). e.5 kg tool. Page 28 of 59 . c. Weigh the assembly correct to a 0. b. Now.JSPM-NTC. Remove the collar and then trim off the excess. Before starting the flow measurements. Coefficient of permeability by Variable Head Method The falling head permeability test is a common laboratory testing method used to determine the permeability of fine grained soils with intermediate and low permeability such as silts and clays. Turn the assembly upside down and remove the compaction plate. The test then starts by allowing water to flow through the sample until the water in the standpipe reaches a given lower limit. Stop watch etc. The permeability mould assembly (including drainage base and drainage cap). the specimen is ready for test. compact the wet soil in 2 layers with 15 blows to each layer with a 2. Apparatus: a. Constant Head Tank d. Place the filter paper or fine wire mesh on the top of the soil specimen and fix the perforated base plate on it. e. This testing method can be applied to an undisturbed sample. Preparation of Sample: a. Put the 3 cm collar to the other end. Assemble the permeameter for compaction. b. Measuring scale. g. Graduated cylinder. b.01gm (W1). Compaction Rammer. Procedure: a. Insert the sealing gasket and place the top perforated plate on the top of soil specimen. Weigh the mould assembly with the soil (W2). mixing pan. And fix the top cap. d. f. c. Grease the inside of the mould and place it upside down on the firm base. Now. m/sec Page 29 of 59 . Initial Time (Ti) (seconds) 2. The recorded time should be the same for each test within an allowable variation of about 10% otherwise the test is failed. Permeability at 270C.JSPM-NTC. Final Time (Tf) (seconds) 4.. 6. Description 1. d. Initial Head (h1) (cm) 3. 7.cm/sec = ……. e.. Observations and Calculations: Diameter of specimen (D) = …………… cm Length of specimen (L) = …………… cm Area of specimen (A= /4*D2) = …………… cm2 Volume of specimen (V=A*L) = …………… cm3 Area of stand-pipe (a) = …………… cm2 Temperature of water = …………… 0C Sr. No. (cm/sec) Average Coefficient of Permeability of Soil is ……. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. Final Head (h2) (cm) Trial – 1 Trial – 2 Trial – 3 (cm/sec) 5. The time required for the water in the standpipe to drop from the upper to the lower level is recorded. Often. the standpipe is refilled and the test is repeated for couple of times. JSPM-NTC. base plates. Page 30 of 59 .75 mm in undrained. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. Weights . Failure occurs when the shearing resistance reaches the maximum value which the soil can sustain. partial drainage is inevitable. Principle:In the direct shear test a square prism of soil is laterally restrained and sheared along a mechanically induced horizontal plane while subjected to a pressure applied normal to that plane.for providing the required normal loads. Proving-Ring of suitable capacity. consolidated undrained and consolidated drained conditions.1986. It is then sheared at a rate of displacement that is slow enough to prevent development of excess pore pressures. porous stones. the relationship between measured shear stress at failure and normal applied stress is obtained. ___ Date: Name of Experiment:Determination of Shear Strength of soil by Direct Shear Test Aim: To determine the shear strength of soil by direct shear test as per IS: 2720 (Part XIII) . and the procedure cannot be used for undrained tests. Stop Clock. Balance. Apparatus: a. Spatula. c. When silty clays and silts are involved. h. The shearing resistance offered by the soil as one portion is made to slide on the other is measured at regular intervals of displacement. By carrying out tests on a set of specimens of the same soil under different normal pressures. and loading pad and water jacket etc. There is no control of drainage. b. Sample Trimmer. The shear box apparatus can be used only for carrying out drained tests for the determination of effective shear strength parameters. e. d. Scope: This experiment covers the methods for determination of shear strength of soil with a maximum particle size of 4. g. The undrained test can be performed only for highlyimpermeable clays. The shear box including grid plates. f. Straight edge etc. The test specimen is consolidated under a vertical normal load until the primary consolidation is completed. As porous stones are not used for the undrained tests. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Preparation of Sample: a.JSPM-NTC. the bulk dry density of the specimen in the shear box shall be determined. For Consolidated Undrained and ConsolidatedDrained Test: The apparatus should be assembled in a way similar to that for 'Undrained test' except that instead of the plain grid plates. Using this information. Alternatively. b. The sample extracted and then trimmed to the required size. the soil may be compacted to the required density and moisture content directly into the shear box after fixing the two-halves of the shear box together by means of the fixing screws. Cohesionless soils may be tamped in the shear box itself with the base plate and grid plate or porous stone as required in place at the bottom of the box. plain plates of equal thickness should be substituted in their place so as to maintain the shear plane in the sample in the middle of its thickness. The cut specimen shall be weighed and trimmings obtained during cutting shall be used to obtain the moisture content. For Undrained Test: The shear box with the specimen. and plain grid plate at the top of the specimen should be fitted into position in the load frame. Cohesive soils may be compacted to the required density and moisture content. plain grid plate over the base plate at the bottom of the specimen. perforated grid plates and saturated porous stones should be used at the top and bottom of the specimen. Page 31 of 59 . c. The orientations of the grid plates should be at right angles to the direction of shear. Secure the horizontal displacement gauge in position. and adjust the drive unit to the correct starting point of the shear test. Continue until the vertical deformation readings shows saturation (which indicates that primary consolidation is complete). Record the initial readings of the horizontal displacement gauge. and maintain it at that level throughout the test. siphon off the water from around the specimen and allow to stand for about 10 min to enable free water to drain from the porous plates. c. Position the box on its bearings on the machine bed. at regular intervals of horizontal. Remove the clamping screws which lock the two halves of the shearbox together. Reverse the direction of travel of the carriage and return the two halves of the shear box to their original alignment. as soon as possible after applying the normal force fill the box with water to a level just above the top of the specimen.JSPM-NTC. smoothly and as rapidly as possible without jolting. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Procedure: I. l. Record the initial zero reading. If the specimen was sheared under water. m. Record readings of the force measuring device. g. i. the horizontal displacement gauge. k. Start the clock at the same instant if consolidation readings are significant. to give the desired vertical stress. Initial Adjustment: a. Record readings of the vertical deformation gauge and elapsed time at suitable intervals. Secure the vertical deformation gauge in position so that it can measure the vertical movement of the center of the loading cap. b. II. d. ensuring that it allows enough movement in either direction. Apply a normal force to the specimen. then stop the test. or until the full travel of the apparatus has been reached if there is no defined peak. the vertical deformation gauge and elapsed time. the vertical deformation gauge and the force measuring device. Start the test and at the same instant start the timer. Page 32 of 59 . III. Except when testing dry soils. j. Assemble the loading system so that the loading yoke is supported by the ball seating on top of the load cap. Shearing: h. Consolidation: e. f. Continue shearing and taking readings beyond the maximum force. Bulk density of specimen( b) (gm/cm3) Dry density of specimen( d) (gm/cm3) Void ratio.01 gm. Remove the vertical force and loading yoke from the specimen. a rate of strain of 0. For sandy soils. Weight of Container (gm) (M1) Weight of Container + Wet Soil (gm) (M2) Weight of Container + Dry Soil (gm) (M3) Moisture Content. taking care not to lose any soil. Remove any free water with a tissue. Degree of Saturation (%). Dry the soil in an oven at 1050C to 1100C and determine its dry mass (md) to 0. and its final moisture content. o. q. For clayey soils.JSPM-NTC. p. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course n. Observations and Calculations: Soil Specimen Measurements: Dimensions of the Specimen : …… (cm) x …… (cm) Area of specimen (As) (cm2) : Thickness of specimen (cm) : Volume of specimen (cm3) : Description Before Starting Test After Completing Test Wet weight of Specimen (gm) Water Content Container No. a rate of strain of 0. Weigh the specimen on the tray to 0. Rate of displacement (mm/min) : Proving ring constant (PRConst) : Least Count of dial gauge : Page 33 of 59 . Transfer the specimen from the shear box to a small tray.01 gm.2 mm/min may be suitable.01 mm/min or slower may be used. . Shear (C) Shear Stress kg/cm2 (D) Hor.kg/cm2 (C) * As Normal Stress = ……….. DEPARTMENT OF CIVIL ENGINEERING (B) Hor.kg/cm2 Proving Ring Reading Horizontal Displacement (A) * LC of dial gauge Horizontal Dial Reading (A) (mm) Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Page 34 of 59 .. Shear (E) Shear Stress kg/cm2 (F) Hor.kg/cm2 (B) * PRConst Normal Stress = ……….JSPM-NTC. Shear (B) Shear Stress kg/cm2 Proving Ring Reading (D) * PRConst (E) * As Proving Ring Reading (F) * PRConst (F) * As Normal Stress = ………. and ii. 2. Angle of Internal friction ( ) or shearing resistance. Result: a.JSPM-NTC.. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Sr. Plot a graph between Normal stress (on X-axis) and Shear stress (on Y-axis) and find: i. CohesionIntercept of given Soil sample is : ……. Angle of Internal friction ( )of given Soil sampleis : ……. No. Shear Stress (kg/cm2) 1.0 Page 35 of 59 .. Normal Stress (kg/cm2) Max. kg/cm2 b. 3. Cohesion intercept (C). Compression device b.01gm e. undisturbed. Moisture can Page 36 of 59 . Where. accurate up to 0. Balance.1991. remolded or compacted. using controlled rate of strain. P = Axial load at failure A = Corrected area of the specimen = A0 = Initial area of the specimen = axial strain = The undrained shear strength (S) of the soil is equal to the half of the unconfined compressive strength. Scope: This experiment describes the method for determining the unconfined compressive strength of clayey soil. The unconfined compressive strength (qu) is the load per unit area at which the cylindrical specimen of a cohesive soil falls in compression.JSPM-NTC. An axial load is applied using either strain-control or stresscontrol condition. Load and deformation dial gauge c. ___ Date: Name of Experiment: Determination of Unconfined Compressive Strength Aim: To determine the Unconfined Compressive Strength(UCS) of soil as per IS: 2720 (Part X) . Sample trimming equipment d. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. Principle:The unconfined compression test is used to measure the shearing resistance of cohesive soils which may be undisturbed or remolded specimens. Apparatus: a. The unconfined compressive strength is defined as the maximum unit stress obtained within the first 20% strain. 1 mm. When the sample is ejected horizontally. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Preparation of Sample: The type of soil specimen to be used for test shall depend on the purpose for which it is tested and may be compacted. Undisturbed sample: a.There will be a significant variation in strength of undisturbed and remolded samples. b.5. Measurements of height and diameter shall be made with suitable measuring device to the nearest 0. This will avoid bending of the specimen and facilitate bringing specimen to vertical position. The height to diameter ratio shall be within 2 to 2. remolded or undisturbed. Page 37 of 59 . a curved plate may be provided to butt against the sampling tube such that the ejected specimen slips over it freely. Specimen of required size may be carved from large undisturbed specimens. The specimen for the test shall have a minimum diameter of 38 mm.JSPM-NTC. beyond 12% axial strain it may be increased even further. The specimen shall be of uniform circular cross-section with ends perpendicular to the axis of the specimen. Compacted specimen may be prepared at any predetermined water content and density. the interval may be increased to 1. or until an axial strain of 20% is reached. The initial length.JSPM-NTC. In the case of failed undisturbed specimen. and reported. After 6% axial strain. d.5 mm of the deformation dial reading. Compacted Specimen: a. if possible. to remold to the same void ratio as that of the undisturbed specimen. and to preserve the natural water content of the soil. preferably in multiples of 100. The upper plate shall be adjusted to make contact with the specimen. The specimen shall be compressed until failure surfaces have definitely developed. the material shall be wrapped in a thin rubber membrane and thoroughly worked with the fingers to assure complete remolding. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. Care shall be taken to avoid entrapped air. Page 38 of 59 . The force reading shall be taken at suitable intervals of the deformation dial reading. d. The deformation dial gauge shall be adjusted to a suitable reading. Three specimens obtained by trimming and carving from undisturbed soil samples shall be tested. After the specimen is formed. c.5 to 2% per minute. to obtain a uniform density. or the stressstrain curve is well past its peak. Representative sample cuttings shall be obtained or the entire specimen and shall be used for the determination of water content after the test. The angle between the failure surface and the horizontal may be measured. b. the ends shall be trimmed perpendicular to the long axis and removed from the mould. Compactionof disturbed material shall be done using a mould of circular cross-section with dimensions as given. diameter and weight of the specimen shall be measured and the specimen shall be placed on the bottom plate of the loading device. readings may be taken at an interval of 0. b. Remolded Specimen: The specimen may be prepared either from a failed undisturbed specimen or from a disturbed soil sample. Procedure: a. Force shall be applied so as to produce axial strain at a rate of 0.0 mm and. Up to 6% axial strain force. c. The water content of the specimen shall be determined. Load at Failure (P) = (PRConst) * A 3. qu. a.. 7.JSPM-NTC.. Weight of Container + Dry Soil (gm) (M3) 12. Deformation at Failure ( L) = LC * B 5. Dial gauge reading at Failure (B) 4.…… cm2 Proving ring Constant (PRConst) : Sr. Weight of Container + Wet Soil (gm) (M2) 11. kg/cm2 Page 39 of 59 . DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course e. Undrained Shear Strength orCohesion (C)of given Soil sample is :……. The maximum stress from this plot gives the value of the UCS. Moisture Content. Observations and Calculations: Diameter of the Specimen : …. Result: a. Proving Ring reading at Failure (A) 2. the undrained shear strength or cohesion of the soil may be taken to be equal to half the UCS. 9. Specimen Stress. In the case of soils which behave as if the angle of shearing resistance = 00. Axial Strain. 8. Description 1. and strain obtained shall be plotted on a graph.. the UCS shall be taken as the stress at 20% axial strain. Values of stress S. In case no maximum stress occurs within 20% axial strain.…… cm Least Count of the dial gauge (LC): Sample – 1 Sample – 2 Sample – 3 = P/A’ 10. Corrected Area. Weight of Container (gm) (M1) S Height of specimen (L0) : …. b. kg/cm2 b.. Water Content Container No.. 6.…… cm Area of specimen (A0) : …. Unconfined Compressive Strength of given Soil sample is : ……. No. d. The diameters and length of the stainless steel rod were limited to 2. it is widely used in geotechnical investigations. d.1980. Calipers Sample Preparation: Prepare two or three specimens of the soil sample of dimensions of at least 37. Need of Test:The vane shear test is an in-situ geotechnical testing methods used to estimate the undrained shear strength of fully saturated clays of low shear strength (less than 0. c. Page 40 of 59 . however. Specimen container. Apparatus: a. Specimen.5 mm diameter and 75 mm length in specimen. Vane shear apparatus: The vane shear test apparatus consists of four stainless steel blades fixed at right angle to each other and firmly attached to a high tensile steel rod. therefore. b. The test is relatively simple. The length of the vane is usually kept equal to twice its overall width. the use of the vane shear test in in-situ testing is much more common.JSPM-NTC. Under special condition. and provides a cost-effective way of estimating the soil shear strength. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No.5mm and 60mm respectively. the vane shear test can be also carried out in the laboratory on undisturbed soil specimens.3 kg/cm2)without disturbance. quick. Scope: This experiment covers the procedure of conducting laboratory vane shear test on cohesive soils of low shear strength for determining their undrained shear strength. (L/D ratio 2 or 3). ___ Date: Name of Experiment: Determination of Undrained Shear Strength by laboratory Vane Shear test Aim: To determine the Undrained Shear Strengthof soil as per IS: 2720 (Part XXX) . b. Measure the height and overall diameter of vane. Torque readings and the corresponding strain readings may also be noted at desired intervals of time as the test proceeds. Note the final reading of the torque indicator/angle of twist. c.JSPM-NTC. Rotate the vane at a uniform rate approximately 0. At the peak value. Gently lower the shear vanes into the specimen to their full length without disturbing the soil specimen so that the top of the vane is at least 10 mm below the top of the specimen. g. Note the readings of the torque indicator/angle of twist. e. Page 41 of 59 . b. d. Mount the specimen container with the specimen on the base of the vane shear apparatus and fix it securely to the base. Shearing strengths in the horizontal and vertical directions are the same.10/second by suitable operating the torque application handle until the specimen fails.kgf of torque shall be used. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Procedure: a. This test is being performed based on the following assumptions: a. shear strength is equally mobilized at the end surfaces as well as at the centre. f. For vane testing instruments that do not read tile torque directly. a calibration curve to convert the readings to cm. No. Final Reading (Degrees) (Degrees) Difference Torque (T) G Shear Strength of Soil = T * G Average Shear Strength (Degrees) (kg-cm) (1/cm3) (kg/cm2) (kg/cm2) 1.JSPM-NTC. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. 2. Observations: Height of vane (H) (cm) : Diameter of vane (D) (cm) : Spring Constant : Initial Reading Sr. 3..kg/cm2 Page 42 of 59 . Result: Undrained Shear Strength of given Soil sample is: ……. The shear surface is cylindrical and has a diameter equal to the diameter of the vane. The moisture content which gives the highest dry density is called the optimum moisture content for that type of compaction. c. Principle:The dry density which can be achieved for a soil depends on the degree of compaction applied and the moisture content.75mm g. To accomplish this. ___ Date: Name of Experiment: Determination of Water Content-Dry Density relation using Light and Heavy Compaction Aim: The objective of this test is to obtain relationships between compacted dry density and soil moisture content. Containers for measuring Water content. Apparatus: a. In general the optimum moisture content is less than the Plastic Limit. Hot Air Oven d. Sieves of sizes 20mm and 4. Steel straightedge f. Balance of sensitivity to 0. The first is a light compaction test using a 2. when the soil in the field is being compactedand the resulting degree of denseness which can be expected from compaction at optimum moisture content. but does not lend itself well to the study of the compaction characteristics of clean sand or gravels which displace easily when struck with the rammer. The second is a heavy compaction test using a 4. internal height of 115 mm and volume of 1000cm3) b. using two magnitudes of manual compaction effort as per IS: 2720 (Part VII-1980 and VIII-1983). Metal rammer Page 43 of 59 . e. Cylindrical Metal mould (with internal diameter of 105 mm. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No.JSPM-NTC. Mixing tools h. Scope: The purpose of a laboratory compaction test is to determine the proper amount of mixing water to be used. The test is used to provide a guide for specifications on field compaction.5 kg rammer with a greater drop on thinner layers of soil (Modified Proctor).5 kg rammer (Standard Proctor). This procedure is satisfactory for cohesive soil.01gm. a laboratory test which will give a degree of compaction comparable to that obtained by the field method used is necessary. b. Add water to the materials and mix thoroughly to bring the moisture content to about 5%. only separated individual particles would be retained. Obtain about 6kg of sample as prepared. c. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Sample Preparation (For Standard as well as Modified Proctor Test): a. Determine the empty weight of the Proctor Mold + base plate (not extension). d. Aggregations of particles shall be broken down so that if the sample was sieved on a 4. b. Page 44 of 59 . shall be taken. This portion shall be sieved on a 20-mm IS sieve and the coarse fraction rejected after its proportion of the total sample shall be recorded.JSPM-NTC.75mm IS sieve. or about 15 kg of material passing a 20-mm IS sieve (for soil susceptible to crushing during compaction). A representative portion of air dried soil material and large enough to provide about 6 kg of material passing 20-mm IS sieve (for soils not susceptible to crushing during compaction). Attach the extension to the top of the mold. Procedure (For Standard Proctor Test): a. Break the rest of the soil cylinder by hand and mix with leftover moist soil.5kg) (dropping from a height of 310mm) before each additional layer of loose soil is poured. 6. Bulk Density (gm/cm3). Weight of Mold + base plate + moist soil (W2) (gm) 3. Continue the test until at least two successive decreased readings are obtained. j. Observation (For Standard Proctor Test): Sr. m. the soil should extend slightly above the top of the rim of the compaction mold. Description 1. From the moist soil extruded. h. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course e. Extrude the compacted moist soil cylinder using a jack. Weight of Container + Dry Soil (gm) (M3) 9. collect sample for determining moisture content. No. Moisture Content. Weight of compacted Moist Soil (W2 – W1) (gm) 4. Trim excess soil with a straight edge. In this process. g. i. 5. Remove the base plate from the mold. Weight of Container (gm) (M1) 7. Compact each layer 25 times uniformly with the light hammer (2. l. Dry Density (gm/cm3). Remove the extension carefully. Add more water and mix to raise moisture content by 2%. Pour the moist soil in three equal layers. n. Repeat steps from ‘d’ to ‘k’. At the end of the three-layer compaction. Water Content Container No. 10. Determine the weight of the Proctor Mold + base plate + compacted moist soil. Weight of Container + Wet Soil (gm) (M2) 8. f. the weight of the mold + base plate + moist soil will first increase with the increase in moisture content and then decrease. Trial1 Trial2 Trial3 Trial4 Trial5 Page 45 of 59 . Weight of Mold + base plate (W1) (gm) 2. k.JSPM-NTC. Weight of Mold + base plate (W1) (gm) 2. Weight of Container + Wet Soil (gm) (M2) 8. 10. Procedure (For Modified Proctor Test): a.Determine the maximum dry unit weight of compaction. Observation (For Modified Proctor Test): Sr. Follow the same procedure as mentioned for the ‘Standard Proctor Test’ by considering the only variations as mentioned below: i. Trial1 Trial2 Trial3 Trial4 Trial5 Plot a graph showing γd (On X-axis) and % Water content (On Y-axis). γd(max) and corresponding optimum moisture content. Weight of Container + Dry Soil (gm) (M3) 9.5kg) instead of light rammer (of 2. Water Content Container No. Bulk Density (gm/cm3). Dry Density (gm/cm3). 6. Description 1. Moisture Content.Determine the maximum dry unit weight of compaction. Weight of Container (gm) (M1) 7. γd(max) and corresponding optimum moisture content. No. Use of Heavy rammer (of 4.5kg) dropping from a height of 450mm. Also plot zero air void line. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Plot a graph showing γd (On X-axis) and % Water content (On Y-axis). Pouring the moist soil in five equal layers instead of three layers. Also plot zero air void line. Weight of compacted Moist Soil (W2 – W1) (gm) 4. 5. Page 46 of 59 . Weight of Mold + base plate + moist soil (W2) (gm) 3. ii.JSPM-NTC. JSPM-NTC. Description a. No. Maximum Dry Density of given Soil sample (gm/cm3) b. Optimum Moisture Content of given Soil sample (%) Standard Proctor Test Modified Proctor Test Page 47 of 59 . DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Result: Sr. surcharge loading and several other environmental factors. by an investigation of those soils likely to possess expansion characteristics. c. Inferential testing is resorted to reflect the potential of the system to swell under different simulated conditions.JSPM-NTC. Oven (1050C to 1100C). Actual magnitude of swelling pressures developed depends upon the dry density. Soil Sample Soil Sample in Kerosene Soil Sample in distilled water Page 48 of 59 . DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. initial water content. d. Sieve (425 micron). Balance (0. Theory:The expansive clays have a tendency to swell in small or more proportion when comes in contact with water.01g accuracy). ___ Date: Name of Experiment: Determination of Free Swell Index (Differential Free Swell) of Soils. b. Apparatus: a. Aim: To determine the free swell index of soil as per IS: 2720 (Part XL) – 1977. Graduated glass cylinder (100ml capacity). Scope: The purpose of determination of free swell index is to understand the increase in volume of soil without any external constraint when subjected to submergence in water. The possibility of damage to structures due to swelling of expansive clays need be identified. The level of the soil in the distilled water cylinder shall be read as the free swell level. not less than 24 hours shall be allowed for soil sample to attain equilibrium state of volume without any further change in the volume of the soils. Fill one cylinder with kerosene and the other with the distilled water up to the 100ml mark. Allow the samples to settle in both the cylinders. Sufficient time. Take two representative oven dried soil samples each of 10gm passing through 425 micron sieve.. Remove the entrapped air in the cylinder by gentle shaking and stirring. Observations and Calculations: The level of the soil in the kerosene graduated cylinder shall be read as the original volume of the soil samples. b. f.JSPM-NTC. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Procedure: a. e. kerosene being a non-polar liquid does not cause swelling of the soil. % Page 49 of 59 . g. d. Volume of soil in cylinder containing Kerosene Volume of soil in cylinder containing distilled water (Vk) cm3 (Vd) cm3 Free Swell Index 1 2 3 Average Free Swell Index (%) Result: Free Swell Index (Differential Free Swell) of given Soil sample is: ……. Sample No. Pour each soil sample in to each of the two glass graduated cylinders of 100ml capacity. Record the final volume of the soils in each of the cylinders. c. ratio of diameter of specimen to maximum size of particle in the soil should not be less than 5. a. i. Generally specimen shall be used: in case of undisturbed sample.JSPM-NTC. the cohesion (C) and the undrained shear strength (Cu). 50. triaxial tests are conducted in three different ways.1993.This experiment covers the methods for determination of the shear strength of unconsolidated undrained specimen of saturated cohesive soil in the triaxial compression apparatus under conditions in which the cell pressure is maintained constant and there is no change in the total water content of the specimen. b. the angle of shear resistance ( ') and the cohesion (C). i.3).Vertical stress is increased by loading the specimen until shear failure occurs. Principle:Triaxial test is more reliable because we can measure both drained and untrained shear strength. Scope: The Triaxial test is primarily designed to determine the shear strength parameters of a soil sample either in terms of total stresses. Unconsolidated Undrained (UU) Triaxial test b. Size of test specimen. ___ Date: Name of Experiment:Determination of Shear Strength of soil by Triaxial Shear Test Aim: To determine the shear strength of unconsolidated undrained soil specimen without measurement of pore water pressure by triaxial shear test as per IS: 2720 (Part XI) . Number of specimens to be tested (minimum 2 . nominal diameter 38.e. axial deformation. Depending on the nature of loading and drainage condition. Measurement of σd. and sample volume change are recorded.or in terms of effective stresses. These values may be used to calculate the bearing capacity of a soil and the stability of slopes. Page 50 of 59 . DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. Specimen is encased by a thin rubber membrane and set into a plastic cylindrical chamber. which is σ1 is equal to the sum of σ3 and deviator stress (σd). pore pressure. Consolidated Undrained (CU) Triaxial test c.e. the angle of shear resistance ( ). Consolidated Drained (CD) Triaxial test Test Conditions: The following test conditions shall be specified before starting a series of tests: a. 70 and 100 mm and of height approximately equal to twice the nominal diameter and in case of remolded samples. Cell pressure is applied in the chamber (which represents σ3’) by pressurizing the cell fluid (generally water). Total vertical stress. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. h. d. accurate up to 0. Whether undisturbed or remolded specimens are to be tested. The largest particle contained within the test specimen must be smaller than one sixth of the specimen diameter. and either the dry density to be achieved or the compactive effort to be applied. Seamless rubber membrane. Cell confining pressures. c. e. f.01gm. b. Triaxial test cell with all necessary accessories. Measuring Scale. Apparatus: a. b. Apparatus for moisture content determination Sample Preparation: a. Split Mould. d. Rubber rings.JSPM-NTC. e. Trimming knife. Balance. For remolded specimens the moisture content. g. Page 51 of 59 . Specimens should have a minimum diameter of 70 mm. The chamber will produce an upward force on the piston that will react against the axial loading device. Handle specimens carefully to minimize disturbance. e. Page 52 of 59 . Determine weight and dimensions of specimen. l. d. and immediately seal it to the specimen base and cap. e. f. Prepare undisturbed specimens from samples obtained from thin walled sampling tubes or other acceptable undisturbed tube sampling procedures. k.JSPM-NTC. or loss of moisture content. g. d. c. b. where necessary. The height to diameter ratio should be between two and three. g. the axial load-measuring device.5% of the estimated compressive strength. Start the test with piston slightly above the specimen cap. and the triaxial chamber to prevent the application of a lateral force to the piston during testing. Record the initial reading on the deformation indicator when the piston contacts the specimen cap. During this procedure. enclose in the rubber membrane.3 mm. f. Fill the chamber with the confining fluid to a predetermined level. Adjust the pressure-maintaining and measurement device to the desired chamber pressure and apply pressure to the chamber fluid. Specimens should be of uniform circular cross section. with ends perpendicular to the axis. i. measured to the nearest 0. Place the chamber in position in the axial loading device. j. Bring the axial load piston into contact with the specimen cap several times to permit proper seating and alignment of the piston with the cap. changes in cross section. The test shall be commenced. h. Remolded samples prepared at the desired moisture and density by static and dynamic methods of compaction or by any other suitable method. measure and record the initial piston friction and upward thrust of the piston produced by the chamber pressure. and before the piston comes in contact with the specimen cap. h. Attach the pressure-maintaining and measurement device. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. Carefully align the axial loading device. take care not to apply a deviator stress to the specimen exceeding 0. Position the specimen in the chamber and assemble the triaxial chamber. A rate of axial compression shall be selected such that failure is produced within a period of approximately 5 to 15 minutes. a sufficient number of simultaneous readings of the load and compression measuring gauges being taken to define the stress strain curve. Test Procedure: a. kg/cm2 Diameter of the Specimen (DS) (mm) Length of specimen (LS) (mm) Area of specimen (As) (cm2) Volume of specimen (Vs) (cm3) Wet weight of Specimen (gm) Water Content Container No. Weight of Container (gm) (M1) Weight of Container + Wet Soil (gm) (M2) Weight of Container + Dry Soil (gm) (M3) Moisture Content. n.. bulging.kg/cm 2 Cell Pressure = ………. Observations and Calculations: Rate of strain OR displacement (mm/min) : Proving ring constant (PRConst) : Least Count of dial gauge (mm) : Cell Pressure = Description ………..kg/cm 2 Cell Pressure = ………. The cell shall be drained of fluid and dismantled. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course m.). The specimen shall be weighed and samples for the determination of the moisture content of the specimen shall be taken. o. The specimen shall then be unloaded and the final reading cf the load measuring gauge shall be recorded as a check on the initial reading. The test shall be continued until the maximum value of the stress has been passed or until an axial strain of 20 percent has been reached. Bulk density of specimen( b) (gm/cm3) Dry density of specimen( d) (gm/cm3) Page 53 of 59 . Prior to placing the specimen (or portion thereof) in the oven to dry. etc.. sketch a picture or take a photograph of the specimen showing the mode of failure (shear plane. and the specimen taken out.JSPM-NTC. kg/cm2 Strain Gauge Reading (mm) Change in length of specimen ( H) Strain Gauge * LC of dial gauge Axial Strain (%) Proving Ring Reading Deviatric Force (kg) Proving Ring * PRConst Corrected area(cm2) Deviatric Stress ( 1) (kg/cm2) Effective Normal Stress Deviatric Force / AC ( 1+ 3) 0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 Page 54 of 59 ..JSPM-NTC. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Cell Pressure( 3) = ………. Record the observations atleast for three samples minimum with various cell pressure. c. No. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Sr. kg/cm2 b. Angle of Internal friction ( ) or shearing resistance.JSPM-NTC. Draw a smooth common tangent to the circlesfind: i.. Deviatric Stress ( 1) (kg/cm2) (kg/cm2) Radius of Mohr Circle Center of Mohr Circle ( 1- ( 1+ 3) /2 3) /2 1.. Result Presentation: a. d. Cohesion intercept (C). Cohesion Intercept of given Soil sample is : ……. Result: a. b. 3.3) /2) and center point at (( 1 + 3) / 2)plot Mohr’s circle for each cell pressure having Normal stress (on X-axis) and Shear stress (on Y-axis). and ii. Slope of the tangent designates Angle of internal friction ( ) and Y-intercept designates Cohesion.0 Page 55 of 59 . Cell Pressure ( 3) Max. 2. Angle of Internal friction ( )of given Soil sample is : ……. With radius of (( 1. Apparatus: a. Since the intrinsic swelling pressure is to be associated with the design of structures against such damages.002mm d. Scope: This experiment covers the laboratory method of conducting one dimensional swelling pressure test using floating rings on remolded soils in the partially saturated condition to determine the swelling pressure of the soil. Besides the dependence of swelling pressure on volume change makes a precise measurement of swelling pressure difficult. if the soil is not allowed to swell or the volume change of the soil is arrested. Dial gauge accurate upto 0. The type and amount of clay in the soil and the nature of the clay mineral. experience severe structural damage due to the swelling of the subsoil. c. Light structures founded on such type of clays-popularly known in India as black cotton soil. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Experiment No. Page 56 of 59 . viz. consolidometer method. Drying and wetting cycles to which the soils have been subjected to. measurement of swelling pressure assumes importance. Aim: To determine the swellingpressure of expansive soil as per IS: 2720 (Part XLI) – 1977. The stress history of the soil including the confining pressure and e. The swelling pressure is dependent upon several factors namely: a. Proving ring of 200kg capacity. The nature of pore fluid. The initial water content and dry density. d. Consolidometer which provides means for submerging the sample and also enable dial gauge to fix b. The expansive clays increase in their volume when they come in contact with water owing to surface properties of these clay types. The main purpose of swelling pressure test is to determine the intrinsic swelling pressure of the expansive soil tested. Method. in which the volume change of the soil is permitted and the measurement of corresponding pressure required to bring back the soil to its original volume is explained.JSPM-NTC. Porous stones. Theory:Swelling Pressure is the pressure which the expansive soil exerts. Water reservoir. e. b. c. ___ Date: Name of Experiment: Determination of SwellingPressure of Expansive Soils. The loading block shall then be positioned centrally on the top porous stone. h. Oven. capable of maintaining a temperature of 1050 to 1100C. Theporous stones shall be saturated by boiling in distilled water for at least 15minutes. Page 57 of 59 . Soil trimming tool. Samples of 60mm diameter and 20mm thick are cut from it. so that the maximumswelling pressure shall berecorded. The diameter to thickness ratio shall be a minimum of 3. All surfaces of the consolidometer which are to be enclosed shall be moistened. Weighing balance. The porous stones shall be saturated. Containers for water content determination Sample Preparation from disturbed soil specimen: a. In case where it is necessary to use disturbed soil samples the soil sample shall be compacted to the desired field density and water content in a standard compaction proctor mould. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course f. g. Procedure: a. i.01gm. providing a filter paper rendered wet between the soil specimen and the porous stone. with an accuracy of 0.JSPM-NTC. b. The initial water content shall be at the shrinkage limit or field water content. b. The consolidometer shall be assembled with the soil specimen (in the ring) and porous stones at top and bottom of the specimen. The dialgauge readings shall be taken till equilibriumis reached. b. This assembly shall then be mounted on the loading frame such that.05 kgf/cm2)shall berecorded atdifferent timeintervals. Thickness of specimen (h) (cm) 5. g.Thesoilshallthen be allowed to swell. allowing smallmargin forthe compression of the soil. Thefreeswellreadingsshownby thedial gaugeunderthe seating loadof5kN/m2(0. Determination of Water Content: 8. Weight of container ring + Wet Soil specimen (gm) (W2) 3. The holder withthedialgauge to recordtheprogressive vertical heaveof the specimen under no load. e.05 kgf/cm2 shallbeplacedontheloading hanger andtheinitial reading of thedialgauge shallbe noted. d. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course c. Observations and Calculations: Sr. No. The equilibrium swellingis normally reached over a periodof 6 to 7daysin generalfor all expansivesoils. Water Content Container No. An initial setting loadof 0. f. Weight of container ring (gm) (W1) 2. Volume of soil sample (cm3). if any. a. The systemshallbeconnectedtoawaterreservoir beingataboutthesamelevelasthesoil with specimen the andwater levelof water allowed inthereservoir to flow inthesample. h. Description 1. Weight of Container (gm) (W1) c. Weight of Container + Dry Soil (gm) (W3) e. the load when applied is transmittedtothesoilspecimen through the loading cap. Moisture Content. 6. Before Test After Test Dry Density of soil (gm/cm3) Page 58 of 59 . The assembly shall be so centered that the load applied is axial.JSPM-NTC. Wet Density of soil (gm/cm3) 7.shallthenbe screwedin placeand adjustedinsuch awaythatthedial gaugeisnear the end ofits release run. Weight of Container + Wet Soil (gm) (W2) d. Diameter of soil specimen (d) (cm) 4. 00 16. Result: Swelling Pressureof given Soil sample is: ………. the swelling has reached its maximum.….00 4.00 1.75 1.) Proving ring reading Start End Difference Load (kg) Swelling Pressure (Diff.00 24.25 0.25 1. If the curve so drawn becomes asymptotic with the abscissa.00 The observed swelling dial reading recorded shall be plotted with elapsed time as abscissa and swelling pressure as ordinates on natural scale. * PRConst) (kg/cm2) 0. A smooth curve shall be drawn joining these points.50 2. DEPARTMENT OF CIVIL ENGINEERING Laboratory Manual for Geotechnical Engineering (201003) SE Civil-2012 Course Initial Setting Load : Proving ring constant (PRConst) : Least Count of Proving ring : Cross section area of specimen (cm2): Elapsed Time (Hrs.00 0..JSPM-NTC.50 0. kg/cm2 Page 59 of 59 .00 8.