chapter  33
Shaft resistance of non-displacement piles in normally consolidated clay
ByL.V. Doan, B.M. Lehane
Pages 6

This paper presents results from a series of tension pile load tests on buried piles in normally consolidated kaolin and compares trends observed with shaft friction inferred from Constant Normal Load (CNL) and Constant Normal Stiffness (CNS) direct shear tests. It is shown that a CNL test with allowance for a 10% reduction in lateral effective stress during shearing provides a simple way of obtaining an accurate estimate of the available pile shaft friction. The capacities predicted using four separate of empirical methods, including more recent CPT methods, are under-predicted by a factor of between 1.5 and 2.2.