Answer Happy

(c) A dam shown in Figure Q1 (c) retains om of water. A sheet pile wall on the upstream side (which is to reduce seepage under the dam) penetrates 4m into a 10m thick of silty sand stratum. Below the silty sand is a thick deposit of clay. Assume that the silty sand is homogeneous and isotropic.
(iii) Analyze the pore water pressure distribution at the base of the dam. (at every 5m @ at points A, B, C, D and E). Given the Nd of points A, B, C, D and E are 5.6, 6.7, 8.0, 10.0, 13.0 respectively. (5 marks) (iv) Determine the uplift force under the dam. (2 marks) (v) Calculate the factor of safety against piping. Given Lmin=0.85m.
6 m 20 m *1.5m 1, B LE 1 F4m 1 1 10 m 1 1 1 1 1 1 Te=0.85 !G-2.67 Ik= 3 x 10 cm/s Impervious clay FIGURE Q1 (c)