1. Side slopes for rock fill 1V:2H. Calculate the minimum crest width of a breakwater using B = 3*kΔ*(W/γa)1/3 . Given data: Stone weight = (8) t, Specific weight = 2,7 t/m3, Layer thickness coefficient =1,00 and Porosity percentage = 37 2.  For cubed shaped stone (or concrete), determine dimension of the stone for weight: W = (10+a) t, specific weight: γa = 2,4 t/m3

A vertical cut is to be made in a purely cohesive clay deposit (c'=30kPa, φ'=0deg, γ=16kN/m3). Find the maximum height of the cut which can be temporarily supported. From the stability chart, the stability number can be used as 0.261.

A wide excavation is made on a site which has the following soil conditions: 0-2 m Gravel:                          gsat = 21.8 kN/m3, gdry = 18.5 kN/m3 2-6 m Silty sand:                     gsat = 19.6 kN/m3, gdry = 18.4 kN/m3 6-21 m Heavy Clay:                gt = 20 kN/m3 21 m and below:                     PERVIOUS sandstone The water table is at a depth of 1.5 m below the ground level. The piezometric pressure head at the top of the pervious sandstone is 5 m above the ground surface. If an excavation of depth 10 m is required, and a factor of safety of 1.5 against heave at the bottom of the clay layer is set, calculate the pressure head reduction required in sandstone.

An embankment consists of clay fill for which c′ = 25 kN/m2 and φ = 27° (from consolidated undrained tests with pore-pressure measurement). The average bulk unit-weight of the fill is 2 Mg/m3. Estimate the shear-strength in kPa of the material on a horizontal plane at a point 20 m below the surface of the embankment, if the pore pressure at this point is 180 kN/m2 as shown by a piezometer.

A retaining wall is 4 metres high. Its back is vertical and it has got sandybackfill upto its top. The top of the fill is horizontal and carries a uniformsurcharge of 85kN/m2. Dry density of soil = 18.5 kN/m3. Moisture content of soil above water table = 12%. Angle of internal friction of soil = 30°, specific gravity of soil particles = 2.65. Porosity of backfill = 30%. The wall friction may be neglected. Determine the following(i) Depth of Zero tension Crack

A 10-m-thick layer of stiff saturated clay is underlain by a layer of sand (Figure 9.28). The sand is under artesian pressure. A 5.75-m-deep cut is made in the clay. Determine the factor of safety against heaving at point A.

A 6m high vertical retaining wall is used to retain a soil of unit weight 18 kN/m3 and slope 20°. The soil is a cohesionless soil with internal friction angle of 40°. Compute the coefficient of active earth pressure from the given data.

An embankment consists of clay fill for which c=25 kPa and angle of internal friction is 260 (from consolidated undrained test with pore pressure measurement) The weight of fill per unit volume is 18.64 kN/m3. Compute the effective stress in kPa at a depth of 20 m. If the pore pressure at this point is shown by a piezometer to be 180 kPa. a. 62.5 b. 372.8 c. 192.8 d. 21.6

Refer to Figure 15.27a. For the braced cut, H = 6 m, Hs = 2 m, s = 16.2 kN/m3, angle of friction of sand, s=34, Hc = 4 m, c = 17.5 kN/m3, and the unconfined compression strength of the clay layer, qu = 68 kN/m2. a. Estimate the average cohesion, cav, and the average unit weight, av, for development of the earth pressure envelope. b. Plot the earth pressure envelope. FIG. 15.27 Layered soils in braced cuts

Problem # 4. A 2m. clay layer has values of e = 0.92, Gs = 2.72 and liquid limit of 40%. Above the clay is a 3m thick layer of sand with e =0.50 and Gs = 2.62. The water table is located 1.6 m below the ground. If a 3m thick backfill is placed on the ground surface having a unit weight of 17.3 kN/m^3, determine the following:  a. Compression index of clay.b. Effective pressure at the midpoint of clay.c. Primary settlement for normally consolidated clay.