Refer to the following figure: 6 m 3 m 2 m 1 m A c,φ,γ 1 m B Given: y = 17.9 kN/m³, c = 60 kN/m², 6 = 0, and center-to-center spacing of struts in the plan = 5 m. The length of the cut is 12.5 m. Determine the factor of safety against bottom heave for the braced cut. Use the equation CNC (1+0.25) FS = զ с x + H B' :) H (Enter your answer to three significant figures.) FS =

A 2.0 m wide strip foundation is placed in sand at 1.0 m depth. The properties of the sand are: γ = 19.5 kN/m3, c′ = 0, and ф′ = 34°. Determine the maximum wall load that the foundation can carry, with a factor of safety of 3.0, using Terzaghi’s original bearing capacity equation with his bearing capacity factors, and Meyerhof’s general bearing capacity equation with shape, depth, and inclination factors from Table 6.3.

The water table at a site is at 5 m below the ground level, and it is required to excavate to this level. The soil profile consists of a thick bed of sand where the unit weight is m = 17.0 kN/m3 above the water table and sat = 20.0 kN/m3 below the water table. The friction angle of the sand is 37. The wall of the excavation will be supported by cantilever sheet piles. How deep would you drive the sheet piles? Use the simplified analysis (Figure 15.37) with a factor of safety of 1.5 on the passive resistance. Determine the maximum bending moment in the sheet pile and the required section modulus for the sheet pile section (given an allowable stress of 190 MN/m2).

For the data given in this problem, determine the magnitude of the active thrust on the wall retaining a c soil, using the procedure discussed in Section 16.10. Given H = 15.0 ft, c = 100 lb/ft2, = 26, = 115 lb/ft3, kv = 0, and kh = 0.3.

Refer to Figure P6.4. A strip load of q = 900 lb/ft2 is applied over a width B = 36 ft. Determine the increase in vertical stress at point A located z = 15 ft below the surface. Given: x = 27 ft. Figure P6.4

For the mat in Problem 16.15, what will be the depth, Df, of the mat for FS = 3 against bearing capacity failure? 16.15 Consider a mat foundation with dimensions of 18 m 12 m. The combined dead and live load on the mat is 44.5 MN. The mat is to be placed on a clay with cu = 40.7 kN/m2 and = 17.6 kN/m3. Find the depth, Df, of the mat for a fully compensated foundation.

It is proposed to place a 9 ft 9 ft foundation at 6 ft depth in a sandy soil, where the average N60 is 25 and the unit weight is 115.0 lb/ft3. Using Meyerhofs expressions presented in Section 9.6, estimate the allowable net pressure that would give 1.2 in. of settlement.