134_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011

134_CEG 4012 Notes Fall 2011 CEG 4012 Notes Fall 2011 - 1...

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DF20 Steel Pipe Piles: Pile Diameter> 36 inches End Bearing: Figure 7 is a plot of mobilized unit end bearing versus blowcount for the four soil types. The empirical equations for the four soil types are presented as follows: Soil Type Description Mobilized Unit End 8earing Capacity (TSF) 1 Plastic clay a = 0.2226*N 2 Clay-silt-sand mixtures, very silty q=0.4101*N sand, silts and marls 3 Clean sands Q = 0.5676*N 4 Soft limestone, very If N s 30, q = 1.2*N shelly sand If N > 30, q = 36.0 + 7.0*(N-30.0)/30.0 The methodology used to calculate the end bearing capacity for a given depth is the same as the concrete pile. This includes the critical depth correction, the end bearing contribution zone of 88 above and 3.58 below the pile tip and the bearing averaging technique remain the same as for concrete piles. Side Friction: Figure 8 is a plot of ultimate unit side friction versus blowcount for the four soil types. The empirical equations derived from the database are as follows; I Soil Type Description Ultimate Unit Side Friction (TSF)
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Unformatted text preview: 1 Plastic clav f = 0.4236*Ln(N) - 0.5404 2 Clay-silt-sand mixtures, very silty f = 0.029 + 0.045*N - 8.98(10-4)*N 2 + sand. silts and marls 6.371 (1 06)*N 3 3 Clean sands f = 0.2028*Ln(N) - 0.2646 4 Soft limestone, very f=0.01*N shelly sand Pile Capacity: Davisson's criteria is not used for this pile type because of the uncertainty of computing elastic settlement for a plugged pile. Instead the mobilized ultimate pile capacity is defined as an applied load at a settlement equal to three percent (3%) the diameter of the pile. The allowable pile capacity is equal to 1/2 the mobilized ultimate pile capacity. The ultimate pile capacity is determined as the ultimate side friction plus two (2) times the mobilized end bearing. It should also be noted that the pile weight is deducted from the total ultimate and failure capacities....
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This note was uploaded on 02/10/2012 for the course CEG 4012 taught by Professor Staff during the Fall '08 term at University of Florida.

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