Coefficient of Lateral Earth Pressure K
The soil around a driven pile is compressed during construction and the lateral earth pressure of this soil acting on the pile skin is greater than the earth pressure at rest (given by coefficient K0) and smaller than the maximum earth pressure (passive earth pressure given by coefficient Kp):
Reference values of the coefficient of lateral earth pressure K are listed later in the table. The coefficient of lateral earth pressure K is approximated as follows:
where: | K0 | - | coefficient of earth pressure at rest |
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φ | - | angle of soil shear resistance | |
Kp | - | coefficient of passive earth pressure | |
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Ka | - | coefficient of active earth pressure | |
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Pressure on the pile
Reference values of the lateral earth pressure coefficient K
Type of pile | K for compression piles | K for tensile - uplifted piles |
Driven H-piles | 0.5 - 1.0 | 0.3 - 0.5 |
Driven displacement piles (round and square) | 1.0 - 1.5 | 0.6 - 1.0 |
Driven displacement tapered piles | 1.5 - 2.0 | 1.0 - 1.3 |
Driven jetted piles | 0.4 - 0.9 | 0.3 - 0.6 |
Bored piles (less than 70cm) | 0.7 | 0.4 |
Literature:
NAVFAC DM 7.2, Foundation and Earth Structures, U.S. Department of the Navy, 1984.