A new underground tunnel section is designed by a geotechnical consultant. For the underground station a 5 m wide braced excavation is made in a saturated clay as shown in Figure Q3 with unit weight, y = 18.5 kN/m, friction angle, o = 0° and cohesion, e = 20 kN/m². The struts are spaced at 5 m center to center in plan. Refer Appendix 1 to select the sheet-pile section. i. Draw the strut forces. ii. Determine the section modulus of the sheet pile needed. Assume oall = 170 MN/m? ii. Determine the maximum moment for the wales at levels B and C. Show a complete answer, including all numerical values and necessary diagrams. 5 m A 1 m

A new underground tunnel section is designed by a geotechnical consultant. For the underground station a 5 m wide braced excavation is made in a saturated clay as shown in Figure Q3 with unit weight, y = 18.5 kN/m, friction angle, o = 0° and cohesion, e = 20 kN/m². The struts are spaced at 5 m center to center in plan. Refer Appendix 1 to select the sheet-pile section. i. Draw the strut forces. ii. Determine the section modulus of the sheet pile needed. Assume oall = 170 MN/m? ii. Determine the maximum moment for the wales at levels B and C. Show a complete answer, including all numerical values and necessary diagrams. 5 m A 1 m

Principles of Foundation Engineering (MindTap Course List)

9th Edition

ISBN:9781337705028

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter19: Braced Cuts

Section: Chapter Questions

Problem 19.1P: A 5 m wide braced excavation is made in a saturated clay, as shown in Figure P19.1, with the...

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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.
Design cantilever sheet-pile wall penetrating a granular soil. a. What is the depth of the embedment, D using FS of 1.5 for strength reduction? b. What should be the minimum section modulus of the sheet piles per unit length? Use all 150 MN/m². Ground water table Dredge line L₁-3 m L₂=5 m D y=17 kN/m² * = 30° You = 18 kN/m² #=30° c'=0 You = 18 kN/m² $'=30* c=0
Figure below shows the cross-section of an excavation which is to be made alongside a river. Write down an expression for the effective stress at level A-A and use this to establish the depth H to which the water in the trench can be reduced before instability occurs (when o'z is zero). The shear resistance at the clay and sheet pile interface can be considered negligible. sheet piling River peaty silt 3.5 m dredge level 8 m . alluvial silty clay 6.0 m (y 18 kN/m³) 3 m coarse 3.5 m gravel impervious red marl
A 10.5m deep excavation in clay is to be retained with an 18m long sheet pile wall. The excavation will proceed with three levels of horizontal struts at the depths as shown in the following figure. The soil is normally consolidated soft clay and alluvium, and the soil properties are shown. Strut 1, GL.-0.5m Strut 2, GL. - 4.0m Strut 3, GL.-7.5m Excavation to GL-10,5m GL. 18.0 m- B " GWT @GL.-1.5m 66 Soft clay: Y=20 kN/m³ Cu=30kPa $=0° Alluvium: 1. Following the example of the lecture notes on the braced cut, calculate and draw the apparent pressure diagram (Peck, 1969) for points O to D on the right side of =)the figure above. Y=20 kN/m³ Cu=100kPa $u=0° ah Kalkp
A construction project of cantilever sheet pile penetrating saturated clay is designed to form a sheet pile wall along a riverbank as shown in Figure C. Determine: i. - ii. The theoretical and actual depth of penetration by using Dactual = 1.5D theory The maximum size of sheet pile section necessary by using all = 172.5 MN/m². Sand A y=16 kN/m³ c' = 0 2m Water table p=32 Sand Ysat 19.35 kN/m³ c' = 0 4'=32 Clay Vsat 19.35 kN/m³ c′ = 46.9 kN/m² 3m Figure C E B Riverbed
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Question- It is proposed to drive H-piles upto a depth of 7 m. The average surface area is 3 m² per meter length. Consider soil is homogeneous sand and have effective friction angle of 32 degrees. GWT is at depth of 2 m below ground surface. Unit weights of soil above and below GWT are 16 & 19 kN/m³ respectively. Earth pressure coefficient K=1.0 and angle of wall friction is 23 degrees. Calculate the total axial frictional resistance (in kN) mobilized on the pile against the driving.
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