20. Observation sheet Approx. settlement, mm Settlement dial readings, division Av. Settlement,d mm Load dial (proving ring dial) reading dividions Load/unit area p, kg/cm 2 Remarks 1 2 3 4 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75

43. Format for recording data Sl no No. of blows Penetration, mm Cumulative no. of blows Cumulative depth, mm 1 0 33 0 0 2 10 53 10 20 3 10 83 20 50 4 10 104 30 71 5 10 125 40 92 6 10 145 50 112 7 10 165 60 132 8 10 183 70 150 9 10 200 80 167

44. Format for recording data Sl no No. of blows Penetration, mm Cumulative no. of blows Cumulative depth, mm 10 10 218 90 185 11 10 230 100 197 12 10 252 110 219 13 10 275 120 242 14 5 295 125 262 15 5 314 130 281 16 5 333 135 300 17 5 352 140 319 18 5 370 145 337 19 5 390 150 357 20 5 405 155

45. Typical plot of no of blows Vs depth of penetration SUBGRADE SUB-BASE COURSE 170 MM BASE COURSE 200 MM SURFACE COURSE 50 MM

53. EQUIPMENTS

55. b) Initial Dial Reading. Determine the thickness of the surcharge base plate and the calibration bar to 0.001 inches using a micrometer. Place the calibration bar across a diameter of the mold along the axis of the guide brackets. Insert the dial indicator gage holder in each of the guide brackets on the measure with the dial gage stem on top of the calibration bar and on the axis of the guide brackets. The dial gage holder should be placed in the same position in the guide brackets each time by means of match marks on the guide brackets and the holder.

57. Maximum Size of Soil Particle Weight of Sample Required(lb.) Pouring Device to be used in Minimum Density Test Size of Mold to be used(cu. ft.) 3 inch 100 Shovel or extra large scoop 0.5 1 – ½ inch 25 Scoop 0.1 3/4 inch 25 Scoop 0.1 3/8 inch 25 Pouring Device (1" diameter spout) 0.1 No 4 (4.75 mm) 25 Pouring Device (1/2" diameter spout) 0.1

61. b ) Fill the mold approximately 1 inch above the top and screed off the excess soil level with the top by making one continuous pass with the steel straight-edge. If all excess material is not removed, an additional continuous pass shall be made but great care must be exercised during the entire pouring and trimming operation to avoid jarring the mold Contd… ….. c) Place soil containing particles larger than 3/8 inch by means of a large scoop (or shovel), hold as close as possible to and just above the soil surface to cause the material to slide rather than fall onto the previously placed soil. If necessary, hold large particles back by hand to prevent them from rolling off the scoop. Fill the mold to overflowing but not more than 1 inch above the top. With the use of the steel straightedge (and the fingers when needed), level the surface of the soil with the top of the measure in such a way that any slight projections of the larger particles above the top of the mold shall approximately balance the larger voids in the surface below the top of the mold d) Weigh the mold and soil and record the weight

67. Where: Ws = weight of dry soil, pounds Vc = calibrated volume of mold, cubic feet Vf = volume of soil, cubic feet = Vc – (Ri – Rf ) / 12 x cu. ft. Rf = final dial gage reading on the surcharge base plate after completion of the vibration period, inches Ri = initial dial gage reading, inches A = cross-sectional area of mold, square feet Density of Soil in Place. Determine the density of the soil in place, Yd, in a compacted fill or a natural deposit in accordance with either the Method of Test for Density of Soil in Place by the Sand-Cone Method ASTM Designation: D1556 or the Method of Test for Density of Soil in Place by the Rubber-Balloon Method ASTM Designation: D2167

72. Shear Box Test Apparatus

75. Observation Sheet Details of specimen: Dimensions: Moisture content: Rate of strain: Normal load applied: Area: Weight: Bulk density: Date of Testing: Shear displacement Corrected area Shear force dial gauge reading Shear force Shear stress Vertical dial readings

77. Table 2. Summary of direct shear test results Test No. Shear displacement at failure Corrected area Normal load applied Normal stress Shear force at failure Shear stress at failure

83. Principle of triaxial shear test

84. T RIAXIAL C OMPRESSION T EST S ET UP

90. Mohr’s circles

91. Observation Table

94. Modulus of deformation or Modulus of elasticity “E” Besides finding the values of c & Ф of the soil, the load-deformation characteristics of the soil are often judged from the stress-strain curves The value of modulus of elasticity “E” or more appropriately, the modulus of deformation, Ed is also obtained from the stress-strain diagram The modulus of deformation is the ratio of stress to strain at an arbitrary point on the stress-strain curve This point may be decided based on allowable % of strain or anticipated stress value Ed = σ d / ε where, ε is the selected strain value and σ d is corresponding value of deviator stress obtained from the triaxial test at selected value of confining pressure σ 3

114. Influence of degree of saturation on permeability of Madison sand

115. Influence of degree of saturation on permeability of compacted silty clay

119. SOIL PERMEABILITY

120. TEST METHODS Constant head permeability test Variable Head Permeability Test Q = k x i x A

122. Constant-head Method

123. Falling –head test This method is suitable for fine-grained soils The soil specimen is placed inside a tube, and a standpipe is attached to the top of the specimen Water from the standpipe flows through the specimen The initial head difference h1 at time t=0 is recorded

124. and water is allowed to flow through the soil such that the final head difference at time t = t is h2

125. Where h1 = initial head, h2 = final head, t= time interval a = cross-sectional area of the liquid stand pipe A =cross-sectional area of the specimen L = length of specimen Clean sand, clean gravel & sand mixture Pervious (good drainage) Fine sand, sandy silt & silt Slightly pervious (poor drainage ) Practically impervious (poor drainage) Homogeneous clay Up to 10 -4 10 -7 10 -5 10 -6 10 -8 10 -9 Or

126. Broad classification of soils as per IS:1498 4.75 MM Soil group Value as Subgrade Value as subbase Drainage characterisitics Compaction Equipment Unit dry wt (g/cc) CBR value,% Subgrade modulus (k) kg/cm 3 GW Excellent Excellent Excellent RTR, SWR 2.0-2.24 40-80 8.3-13.84 GP Good to ex Fair to G Excellent RTR, SWR 1.76-2.24 30-60 8.3-13.84 GM Fair to G Fair to G Fair to P RTR, SFR 1.76-2.24 30-60 8.3-13.84 GC Good Fair Poor to PI RTR, SFR 1.84-2.16 20-30 5.53-8.30 SW Good Fair to G Excellent RTR 2.08 -2.32 20-40 5.53-11.07 SP Fair to G Fair Excellent RTR 1.68-2.16 10-40 4.15-11.07 SM Fair to G Fair to G Fair to PI RTR, SFR 1.60-2.16 10.2-40 4.15-11.07 SC Fair to P Not Suitble Fair to PI RTR, SFR 1.60-2.16 5-20 2.77-8.30 ML,MI Poor to F Not Suitble Fair to P RTR, SFR 1.44-2.08 15 or less 2.77-5.53 CL, CI Poor to F Not Suitble Impervious RTR, SFR 1.44-2.08 15 or less 1.38-4.15 OL,OI Poor Not Suitble Poor RTR, SFR 1.44-1.68 5 or less 1.38-2.77 MH,CH, OH Not suitble Not suit Impervious RTR, SFR 1.28-1.68 5 or less Less than 2.5 GRAVEL SILT SAND COARSE SAND MEDIUM SAND FINE SAND CLAY 2.0 MM 0.425 MM 0.075 MM 0.002 MM

127. Highly expansive in nature & will have less permeability

129. Silicon-oxygen tetrahedron It consists of four oxygen atoms surrounding a silicon atom It consists of six hydroxyl units surrounding an aluminum (or magnesium) atom Aluminum or Magnesium octahedral units

130. Silica sheet Gibbsite sheet Silica – gibbsite sheet The tetrahedron units combine to form a silica sheet Combination of the aluminum octahedral units forms

131. Each silicon atom with a positive valance of 4 is linked to four oxygen atoms with a total negative valance of 8 However, each oxygen atom at the base of the tetrahedron is linked to two silicon atoms This leaves one negative valance charge of the to oxygen atom of each tetrahedron to be counterbalanced The combination of the aluminum octahedral units forms a gibbsite If the main metallic atoms in the octahedral units are magnesium, these sheets are referred to as brucite sheets When the silica sheets are stacked over the octahedral sheets, the oxygen atoms replace the hydroxyls to satisfy their valance bonds

133. Illite & Montmorillonite minerals The most common clay minerals with three-layer sheets are illite and montmorillonite A three layer sheet consists of an octahedral sheet in the middle with one silica sheet at the top and one at the bottom Repeated layers of these sheets form the clay minerals

134. Illite mineral Montmorillonite mineral Illite layers are bonded together by pottasium ions

135. The negative charge to balance the pottasium ions comes from the substitution of aluminum for some silicon in the tetrahedral sheets Substitution of this type by one element for another without changing the crystalline form is known as isomorphous substitution Montmorillonite has a similar structure to illite. However, unlike illite there are no pottasium ions present, and a large amount of water is attracted into the space between the three sheet layers

137. FSI Usefulness This test helps to identify the potential of a soil to swell which might need further detailed investigation regarding swelling and swelling pressures under different field conditions Take two 10 g soil specimens of oven dry soil passing through 425-micron IS Sieve Each soil specimen shall be poured in each of the two glass graduated cylinders of 100 ml capacity In the case of highly swelling soils, such as sodium bentonites, the sample size may be 5 g or alternatively a cylinder of 250 ml capacity may be used

138. Free Swelling Index

139. One cylinder shall then be filled with kerosene oil and the other with distilled water up to the 100 ml After removal of entrapped air ( by gentle shaking or stirring with a:tglass rod ), the soils in both the cylinders shall be allowed to settle Sufficient time (not less than 24 h ) shall be allowed for the soil sample to attain equilibrium state of volume without any further change in the volume of the soils The final volume of soils in each of the cylinders shall be read out

140. Free swell index, percent = (Vd – Vk) / Vk x 100 Where V d= the volume of soil specimen read from the graduated cylinder containing distilled water, and Vk, = the volume of soil specimen read from the graduated cylinder containing kerosene.

141. Laboratory observations Initial Reading Final Reading Difference in Reading FSI, % Soil + Water Kerosene Soil + Water Kerosene 13 11 17 11 6 54.5 13 11 16.8 11 5.8 52.7 14 12 18.2 12 6.2 51.7 13.5 12 18 12 6 50.0 13 11 16.8 11 5.8 52.7 14 11 17 11 6 54.5 13.5 11 16.5 11 5.5 50.0 13.5 11 16.8 11 5.8 52.7 13.5 11 16.7 11 5.7 51.8 14.5 11 17 11 6 54.5

153. Poisson’s ratio The Poisson’s ratio, µ is the ratio of the strain normal to the applied stress to the strain parallel to the applied stress

155. THANKS