A pit of 6.4 m deep is to be excavated in a fine sand stratum completely saturated up to the ground surface. The saturated unit weight of the sand was obtained as 20.3 kN/m³. To stabilize the bottom of the excavation (prevent boiling), it was decided to drive steel sheet piles to act as cutoff walls that encircle the excavation. Determine the total length of sheet pile wall to provide a factor of safety of 1.5 against sand boiling. Assume specific gravity of soil, G, = 2.7 and unit weight of water, 7.-9.81 kN/m³.

A pit of 6.4 m deep is to be excavated in a fine sand stratum completely saturated up to the ground surface. The saturated unit weight of the sand was obtained as 20.3 kN/m³. To stabilize the bottom of the excavation (prevent boiling), it was decided to drive steel sheet piles to act as cutoff walls that encircle the excavation. Determine the total length of sheet pile wall to provide a factor of safety of 1.5 against sand boiling. Assume specific gravity of soil, G, = 2.7 and unit weight of water, 7.-9.81 kN/m³.

Principles of Foundation Engineering (MindTap Course List)

9th Edition

ISBN:9781337705028

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter18: Sheet-pile Walls

Section: Chapter Questions

Problem 18.1P: Refer to Figure 18.9. A cantilever sheet pile is driven into a granular soil where the water table...

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A 5 m wide braced excavation is made in a saturated clay, as shown in Figure P19.1, with the following properties: c = 20 kN/m2, = 0, and = 18.5 kN/m3. The struts are spaced at 5 m center to center in plan. a. Determine the strut forces. b. Determine the section modulus of the sheet pile required, assuming all = 170 MN/m2. c. Determine the maximum moment for the wales at levels B and C.
Figure 15.53 below shows a cantilever sheet pile driven into a granular soil where the water table is 2 m below the top of the sand. The properties of thesand are: ' = 40, m = 17.5 kN/m3, and sat = 19 kN/m3. It is proposed toexcavate to a depth of 6 m below the ground level. Determine the depth towhich the sheet pile mast be driven, using the net lateral pressure diagram. Fig. 15.53
Problem #1 The figure below shows a cantilever sheet-pile wall penetrating a granular soil. Here, L1 = 4 m, L2 = 8 m, unit weight above water table= 16.1 kN/m3, saturated unit weight = 5 18.2 kN/m3, and friction angle of sand = 32 degrees. a. What is the theoretical depth of embedment, D? b. For a 30% increase in D, what should be the total length of the sheet piles? c. Determine the theoretical maximum moment of the sheet pile. d. If the allowable flexural stress = 170 MPa, compute the required section modulus of the sheet pile.
An anchored sheet-pile bulkhead is shown in Figure P14.10. Let L1 = 2 m, L2 = 6 m, l1 = 1 m, γ = 16 kN/m3, γsat = 18.86 kN/m3, Φ' = 32º, and c = 27 kN/m2.a. Determine the theoretical depth of embedment, D.b. Calculate the anchor force per unit length of the sheet-pile wall. Use the free earth support method.
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).
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Redo Problem 14.1 with the following: L1 = 3m, L2 = 6 m, γ = 17.3 kN/m3, γsat = 19.4 kN/m3, and ϕ′ = 30°. 14.1 Figure P14.1 shows a cantilever sheet-pile wall penetrating a granular soil. Here, L1 = 4 m, L2 = 8 m, γ = 16.1 kN/m3, γsat = 18.2 kN/m3, and ϕ′ = 32°. What is the theoretical depth of embedment, D? For a 30% increase in D, what should be the total length of the sheet piles? Determine the theoretical maximum moment of the sheet pile.
Determine (a) the lateral earth pressure distribution for the braced cut analysis (including shape and value of earth pressure), (b) the strut loads for the horizontal supports of the braced cut. The lateral spacing, S,between the struts is 3 m. (c) Determine the factor of safety against bottom heave, if the length and width of the excavation are 20 m and 15 m,respectively, and the depth of the bottom of the excavation to the gravel layer is 6 m.
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Determine the factor of safety against heave on the downstream side of the single-row sheet pile structure shown in Figure 9.30. Use the following soil and design parameters: H1 = 7 m, H2 = 3 m, thickness of permeable layer (T) = 12 m, design depth of penetration of sheet pile (D) = 4.5 m, and γsat = 17 kN/m3
Draw a flow net for a single row of sheet piles driven into a permeable layer as showin Figure Q3 (b) below. Thus, determine the seepage loss per meter length of thesheet pile.H1 = 9.6 m D = 5 mH2 = 3.7 m D1 = 13 m
Refer to Figure 18.9. A cantilever sheet pile is driven into a granular soil where the water table is 2 m (L1) below the top of the sand. The properties of the sand are =40, =17.5kN/m3, and sat=19kN/m3. It is proposed to excavate to a depth of 6 m (L) below the ground level. Determine the actual depth to which the sheet pile must be driven (L + D), using the net lateral pressure diagram. Note: Dactual=1.3(L3+L4)theory