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End Bearing Capacity of Drilled Shafts in Sand: A Numerical Approach

  • M. M. Ahmadi
  • M. Khabbazian
Original Paper

Abstract

In this paper, a modeling procedure is carried out to numerically analyze the end bearing capacity of drilled shafts in sand. The Mohr–Coulomb elastic plastic constitutive law with stress dependent elastic parameters is used for all numerical analyses performed in this study. The numerical results are compared with the available experimental equations. It is seen that numerical results are in good agreement with experimental equations. The variation of the end bearing capacity of drilled shafts versus embedment depth is also studied. Numerical results show that with increase in pile embedment depth, the end bearing capacity increases. However, the rate of increase becomes smaller as the pile embedment depth increases. Also, numerical analyses show that, for equal settlement, the end bearing decreases with increase in the pile diameter. Finally, a sensitivity analysis is performed to obtain the separate effect of each sand parameter on the end bearing capacity of drilled shafts, and the parameters that are most influential are identified.

Keywords

Drilled shaft Embedment depth End bearing capacity Numerical modeling Sand 

Notations

B

Pile diameter

c

Cohesion

Dr

Relative density

E

Elasticity modulus

G

Shear modulus

K

Bulk modulus

KB

Bulk stiffness number

KG

Shear stiffness number

Ko

Coefficient of lateral earth pressure at rest

L

Embedment depth of drilled shaft

m

Stress exponent

n

Stress exponent

N

The average standard penetration resistance in blows per foot near the pile tip

PA

Atmospheric pressure

qp

End bearing capacity

S

Pile tip displacement

φ

Friction angle

φcrit

Critical angle of shearing resistance of sand

γ

Sand density

ν

Poisson ratio

σ′m

Mean effective stress

ψ

Dilation angle

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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Department of Civil EngineeringSharif University of TechnologyTehranIran

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