Drilled Shaft Examples

Drilled Shaft Examples - Good site investigation therefore...

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Drilled Shaft Example, Sand No static test Uniform Site Average site investigation therefore FS = 3.0 γ concrete = 23.6 kN/m 3 pile weight: W = [23.6 kN/m 3 (2m) + (23.6-9.81 kN/m 3 ) (12 m)] x π (0.6 m) 2 /4] = 60.1 kN bearing: q t = 57.5 (22 blows/0.3m) = 1265 kPa A t = π B b 2 /4 = π (0.6) 2 / 4 = 0.283 m 2 Q t = 1265 kPa ( 0.283 m 2 ) = 358 kN side shear: use β method, v s ' f βσ = where m , z 245 . 0 5 . 1 - = β Layer Depth C.L. m Thickness m σ v kPa β f s = βσ v kPa A s = π B Δ L m 2 Q s = f s A s kN Silty Sand above GWT (0-2 m) 1.0 2.0 17.0 1.20 (max) 20.4 3.77 77 Silty Sand below GWT (2-3.5 m) 2.75 1.5 41.6 1.09 45.2 2.83 128 Sand (3.5-9m) 6.25 5.5 77.3 0.88 68.0 10.37 705 Sand (9-14 m) 11.5 5.0 130.9 0.68 89.0 9.42 838 Σ Q s 1748 allowable load: kN 682 3.0 60.1 358 1748 P a = - + = 2.0 m 1.5 m 5.5 m 0.6 m Silty Sand, γ m = 17 kN/m 3 , γ sat = 20 kN/m 3 Well graded Sand, γ sat = 20 kN/m 3 , Avg. N 60 1.2 m below toe = 22 blows/0.3m γ w = 9.81 kN/m 3 5.0 m Poorly graded Sand, γ sat = 20 kN/m 3
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Drilled Shaft Example, Clay No static test Uniform Site
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Unformatted text preview: Good site investigation therefore FS = 2.5 GWT at 100 ft concrete = 105 pcf pile weight: W = 150 pcf [(58.5 ft) (2) 2 /4 + ( /12)(1.5 ft)(2 2 + 5 2 + 2x5)] / 1000 = 29.9 kips bearing: q t = 9 (4.0 ksf) = 36.0 ksf A t = B b 2 /4 = 5 2 / 4 = 19.6 ft 2 Q t = 36.0 ksf ( 19.6 ft 2 ) = 705.6 kips side shear: use method, note = 0 for 5 from head and (1.5 ft + B) = 3.5 ft above toe Layer Depth ft Thickness ft c u ksf f s = c u ksf A s = B L ft 2 Q s = f s A s kips 1 0-5 5 - 0 0 0 0 2 5-12 7 1.6 0.55 0.88 44 39 3 12-37 25 1.4 0.55 0.77 157 121 4 37-56.5 19.5 4.0 0.48 1.92 122 234 5 56.5-60 3.5 - 0 0 0 0 Q s 394 allowable load: kips 428 2.5 29.9 394 705.6 P a =-+ = 12 ft 25 ft 23 ft 1.5 ft 5 ft 2 ft Stiff Silty Clay, = 105 pcf, c u = 1.6 ksf Stiff Clay, = 108 pcf, c u = 1.4 ksf Very Stiff Clay, = 109 pcf, c u = 4.0 ksf...
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This note was uploaded on 09/12/2011 for the course CEG 4012 taught by Professor Staff during the Fall '08 term at University of Florida.

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Drilled Shaft Examples - Good site investigation therefore...

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