Determine the lateral earth force at rest per unit length of the retaining wall when the ground water table is acting at 2m below ground surface and find out the location of the resultant force. Clay layer overlies sand layer.

Q2. A soil profile consisting of three layers is shown in Figure 1 below. Unit weight of water (yw) = 9.81 kN/m³ Layer no. 1 2 3 ↑ H₁ H₂ Dry sand Sand Clay Rock Figure 1: Soil Profile Thickness H₁ = 1.5 m H₂ = 2.53 m H3 = 2.64 m Layer 1 Groundwater table Layer 2 Layer 3 Soil parameters Yd = 16.5 kN/m³, Ysat = 17.42 kN/m³ Ya = 16.5 kN/m³, Ysat = 18.55 kN/m³ Yd = 17.50 kN/m³, Ysat = 19.23 kN/m³ a) Calculate the values of o, u and o' at points A, B, C and D. b) Calculate the effective stress at C when water table drops by 2 m. c) Calculate the effective stress at C when water table rises by 1 m above layer 1 due to flooding.

Problem 7.19 only.

Problem 4: Total stress, pore pressure and effective stress A soil profile is shown in the following figure. Calculate the total stress, pore water pressure and effective stress at points A, B, and C. 6m 13m B Dry sand Saturated sand Clay Dry sand Ydry 16.5 kN/m³ Groundwater table Saturated sand Ysat 19.25 kN/m³ =

A reservoir-rock sample has a porosity of 0. 18 measured at 14.7 psis. The rock compressibility is0.77 X 10 5psi *.What would the rock porosity be at 2,000 and at 3,000 psis? Plot the relationship be tween ¢ and p in a pressure range of 14.7 to 5,000 psis