Chapter 15, Problem 15.11P

A braced cut is carried out to 10 m depth at a site where the soil consists of 4 m of sand ( = 17.0 kN/m3, = 33) at the top underlain by 6 m of clay ( = 18.5 kN/m3, c = 35 kN/m2). a. What would be the average value of cohesion and the unit weight for the equivalent homogeneous soil profile? b. Show the lateral earth pressure envelope you would use in determining the strut loads.

Q9.1 -  A 25-m high rock cut with a face angle of 60° has been excavated in a massive, very weak volcanic tuff. A tension crack has opened behind the crest and it is likely that the slope is on the point of failure, that is, the factor of safety is approx imately 1.0. The friction angle of the material is estimated to be 35°, its density is 25kN / (m ^ 3) and the position of the water table is shown on the sketch of the slope (Figure 4). The rock contains no continuous joints dipping out of the face, and the most likely type of failure mode is circular failure. Required- (a) Carry out a back analysis of the failure to determine the limiting value of the cohesion when the factor of safety is 1.0. (b) Using the strength parameters calculated in (a), determine the factor of safety for a completely drained slope. Would drainage of the slope be a feasible method of stabilization?  (c) Using the ground water level shown in Figure 4 and the strength parameters calculated in (a), calculate the…

Determine the total active thrust, in kN/m, for a retaining wall (height 5.12 m.) with horizontal backfill given the following properties: Unit weight = 17.79 kN/m3, Angle of internal friction = 30°, Cohesion = 11.71 kPa, and Surcharge = 9.33 kPa.

Determine the total active thrust, in kN/m, for a retaining wall (height 4.77 m.) with horizontal backfill given the following properties: Unit weight = 17.49 kN/m3, Angle of internal friction = 32°, Cohesion = 11.32 kPa, and Surcharge = 8.6 kPa. Round off to two decimal places.

The elevation and plan of a bracing system for an open cut in sand are shown in Figure 14.21. Using Pecks empirical pressure diagrams, determine the design strut loads. Given: sand = 18 kN/m3, ' = 38, x = 3 m, z = 1.25 m, and s = 3 m.

A retaining wall has a vertical back and is 7.32 m high. The soil is sandy loam of unit weight 17.30 KN/cum, it shows a cohesion of 12KPa and angle of friction 20 degrees. Neglecting the wall friction, determine the thrust on the wall in KN/m. The upper surface of the fill is horizontal. 121 343 232 104

A braced wall is shown in Figure 14.20. Given: H = 7 m, naH = 2.8 m, =30, =20, = 18 kN/m3, and c = 0. Determine the active thrust, Pa, on the wall using the general wedge theory. Figure 14.20