Bearing Capacity and Settlement of Pile Foundations

Abstract

Conventional bearing capacity of driven and bored piles in sand and nonplastic silt is limited to short piles above the critical depth of penetration. The bearing capacity of longer piles can be estimated from the limiting values of the point resistance and skin friction using either the friction angle of the soil or preferably the results of static and standard penetration tests directly. For driven and bored piles in clay and plastic silt, conventional bearing capacity theory using the undrained shear strength of the soil represents mainly the failure condition at the pile points. The positive and negative shaft resistance some months after pile installation is governed by the drained shear strength of remolded soil and can be estimated from skin friction factors, provided the earth pressure coefficient at rest of the deposit is known. The ultimate load of pile groups and the settlement of pile foundations are examined.