Qatar University College of Engineering Department of Civil & Arch. Engineering 1. Direct shear box test results for clayey sand specimens tested at three different normal stresses are shown in Table

1. a. Plot the shear stress-shear displacement relationship and determine the peak shear strength at each normal stress. At which value of shear displacement would the peak shear strength be mobilized? b. Draw the failure envelope for the peak shear strength. Use the same scale for the x and y axes. e. Determine the shear strength parameters and write the equation that can be used to estimate the peak shear strength (5,) of the tested soil. Table 1. Test results for soil tested in direct shear apparatus Normal Stress (G)-42 kPa Time, see (t) 0 30 60 90 120 150 Proving ring reading (Div.) 0 15.9 27.4 37.1 45 52 Foundation Engineering I (CVEN 330) Assignment No. 1 (Sep. 21, 2023) 180 210 240 270 300 330 360 390 420 450 480 510 540 Use the following to process the data: 57.4 61.8 65.2 68.8 69.7 68 61.8 15.9 G-78 kPa Proving ring reading (Div.) 0 31.8 51.2 65 • Area of shear box-6×6 cm² -0.0036 m² Shear rate=0.01 mm/sec • Proving ring constant-0.00204 kN/div • 74.1 85.4 93.2 104.8 108.7 109.4 108.5 98.8 31.8 G-130 kPa Proving ring reading (Div.) 0 45.9 70.6 91.75 Shear Displacement, &-Shear rate time Shear Force, T-Proving ring constant Proving ring reading Shear Stress, T-T/cross-section area of shear box 107.65 120 129.5 138.7 146.1 151.2 157.95 162.35 166.2 169.4 171.9 174 175.5 173.5 169.4 Hint: You may use the following equations to process the data of the table, and show detailed calculations in your solution.