A hydraulic-excavator backhoe is excavating the basement for a building. Heaped bucket capacity is 1.15 m3. The material is common with a bucket fill factor of 0.90. Job efficiency is 51 min/h. Average depth of cut is 2.7 m. Maximum depth of cut is 9.0 m and average swing is 75 degrees.

Q-4: The following figure shows the flow net for seepage of water around a single row of sheet piles driven into a permeable layer. Calculate how deep the sheet pile should be driven (h) to achieve factor of safety = 3 against downstream heave, given that ysat for the permeable layer = 18 kN/m3. (Note: Thickness of permeable layer T = 18 m) H₁ = 10 m (h) Heave zone Sheet pile ►||1| Impermeable layer H₂ = 2 m Ysat 18 kN/m³

A 3 m deep excavation will be supported by a cantilever sheet pile. The foundation soil is dense sand, but it is assumed that the pile tip penetrates impermeable soil so hydrostatic pore pressure can be used. A surcharge of 10kPa is applied at the ground level. The water table is at the ground surface and dredge line as shown. Use Yw=10kN/m³ for your calculations. a) Using a factor of safety of 2.0 for Kp, check if D'=5m is safe or not (no need to iterate for other D'). b) Calculate the maximum bending moment. H=3.0m D.L. =+% D'=5m? 10 kPa G.L. Dense sand 3 Yt=20.0 kN/m³ c'=0 Ka=0.2 Kp=6.0 Impermeable soil

3. Consider the sheet pile wall shown below. Assume the water is 20m above the ground surface on the left side of the sheet pile and the wall penetrates 18m below the ground surface. Using the flow net shown below and assuming k=0.05 m/day. Calculate: 1) quantity of water flow in 5 days for each meter length into to page, and 2) the water pressure at point A. 5m B