A 12 m long and 600 mm diameter drilled shaft installed in a sand soil. The nominal side friction capacity of the drilled shaft, fn As, is 800 kN and nominal toe-bearing capacity, qn'At, is 700 kN. The modulus of elasticity of the drilled shaft, E, is 30,000 MPa. Compute the settlement of the drilled shaft for a surface load of 600 kN.

A 12 m long and 600 mm diameter drilled shaft installed in a sand soil. The nominal side friction capacity of the drilled shaft, fn As, is 800 kN and nominal toe-bearing capacity, qn'At, is 700 kN. The modulus of elasticity of the drilled shaft, E, is 30,000 MPa. Compute the settlement of the drilled shaft for a surface load of 600 kN.

Principles of Foundation Engineering (MindTap Course List)

9th Edition

ISBN:9781337705028

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter13: Drilled-shaft Foundations

Section: Chapter Questions

Problem 13.2P

See similar textbooks

Similar questions

For the drilled shaft described in Problem 19.7, estimate the total elastic settlement at working load. Use Eqs. (18.45), (18.47), and (18.48). Assume that Ep = 20 106 kN/m2, s = 0.3, Es = 12 103 kN/m2, = 0.65 and Cp = 0.03. Assume 80% mobilization of skin resistance at working load. (See Part c of Problem 19.7) 19.7 Figure 19.16 shows a drilled shaft without a bell. Here, L1 = 6 m, L2 = 7 m, Ds = 1.5 m, cu(1) = 50 kN/m2, and cu(2) = 75 kN/m2. Find these values: a. The net ultimate point bearing capacity. Use Eqs. (19.23) and (19.24) b. The ultimate skin resistance. Use Eqs. (19.26) and (19.28) c. The working load, Qw (FS = 3) FIG. 19.16
Refer to Figure 11.26b. For the drilled shaft with bell, given:Thickness of active zone, Z = 9 mDead load = 1500 kN Live load = 300 kNDiameter of the shaft, Ds = 1 mZero swell pressure for the clay in the active zone = 600 kN/m2Average angle of plinth-soil friction, Φ'ps = 20°Average undrained cohesion of the clay around the bell = 150 kN/m2. Determine the diameter of the bell, Db. A factor of safety of 3 against uplift is required with the assumption that dead load plus live load is equal to zero.
For the drilled shaft described in Problem 19.7, determine these values: a. The ultimate load-carrying capacity b. The load-carrying capacity for a settlement of 25 mm Use the procedure outlined in Section 19.8. 19.7 Figure 19.16 shows a drilled shaft without a bell. Here, L1 = 6 m, L2 = 7 m, Ds = 1.5 m, cu(1) = 50 kN/m2, and cu(2) = 75 kN/m2. Find these values: a. The net ultimate point bearing capacity. Use Eqs. (19.23) and (19.24) b. The ultimate skin resistance. Use Eqs. (19.26) and (19.28) c. The working load, Qw (FS = 3) FIG. 19.16
An 8 in diameter drilled shaft will penetrate through an expansive stiff clay to a depth well below the active zone. It will carry a downward load of 5,200 lb. The undrained shear strength of the clay is 900 psf and the active zone extends to a depth of 10 ft. Determine the following:a. What is the uplift skin friction load?b. Is a tensile failure in the shaft possible (do not forget to consider the weight of the shaft)?c. What is the required reinforcing steel to prevent a tensile failure (if necessary)? Use fy = 40 k/in2 and a load factor of 1.7.
Figure P10.7 shows a drilled shaft without a bell. Assume the following values:L1 = 6 m cu(1) = 50 kN/m2L2 = 7 m cu(2) = 75 kN/m2Ds = 1.5 mDetermine:a. The net ultimate point bearing capacity [use Eqs. (10.33) and (10.34)]b. The ultimate skin friction [use Eqs. (10.37) and (10.39)]c. The working load Qw (factor of safety = 3)
An Osterberg load test is to be conducted on a 60 in diameter, 75 ft long drilled shaft. The expected nominal side friction capacity is 2,000 lb/ft2 and the expected nominal net toe bearing capacity is 60,000 lb/ft2. (a) Determine the optimal jack location such that the load capacity above the jack is equal to that below the jack. (b) Compute the required jack capacity.
An 8 in diameter drilled shaft will penetrate through an expansive stiff clay to a depth well below the active zone. It will carry a downward load of 5,200 lb. The undrained shear strength of the clay is 900 psf and the active zone extends to a depth of 10 ft. Determine the following: What is the uplift skin friction load? Is a tensile failure in the shaft possible (do not forget to consider the weight of the shaft)? assume: unit weight concrete = 150pcf, Concrete has no tensile strength. Assume full active zone in calculations.
For the drilled shaft described in Problem 10.1, what skin resistance would develop in the top 6 m, which are in clay ?
Define the Normalized Tip Resistance of Drilled Shafts in Sand (Ghionna et al. 1994) ?