Pile Design and Construction Practice, Fifth edition

slurrying of the walls of the borehole and, in the most adverse case, the shaft friction corresponds to that typical of a smooth ...

Resistance of piles to compressive loads 207 Rock socket shaft friction Unconfined compression strength-quc (MN/m^2 ) =fs=abquc ...

where is the rock strength defined as above and RF is a roughness factor given as (4.47) where average height of asperities rs n ...

formation of a very soft sludge at the bottom of the drillhole which, apart from weakening the base resistance, makes it difficu ...

resistance. If the safety factor to obtain the allowable load is too low, the resulting shaft settlement could break down the bo ...

The factor should be based on SPT N-values. For low values of N(less than or equal to 10) or a cone resistance qcbetween 2 and ...

weathering grade and the unconfined compression strength of the rock given in Table 4.18 and Section 5.5. These relationships ar ...

2.0 1.6 1.2 0.8 0.4 Influence factor , lp 0.20 0.16 0.12 0123456789 200 L/B 100 50 20 10 1.0 Q 0.4 R=2 Ed Qlp BEd Ed B = R= Ec E ...

or rock. No support for compressive loads from shaft friction can be assumed over the length of the pile shaft through the fill. ...

Resistance of piles to compressive loads 215 (a) (b) Residual negative skin friction operating Peak negative skin friction Movem ...

Pile compresses elastically relative to fill and negative skin friction is eliminated Original surface of fill Peak W 0.IH H W L ...

also significant. In old fill which has become fully consolidated under its own weight and where it is not proposed to impose su ...

progressive increase in negative skin friction on two precast concrete piles driven through 40 m of soft compressible clay and 1 ...

used the depth Hover which the upper-bound force is assumed to act is critical. If the depth is over-estimated application of th ...

Claessen and Horvat(4.63)describe the coating of 380 450 mm precast concrete piles with a 10 mm layer of bitumen having a penet ...

4.11SKEMPTON, A. W. Cast in-situ bored piles in London Clay, Geotechnique, Vol. 9, No. 4, 1959, pp. 153–73. 4.12FLEMING, W. G. K ...

4.35WHITE, D. J. and BOLTON, M. D. Comparing CPT and pile base resistance in sand, Proceedings of the Institution of Civil Engin ...

Resistance of piles to compressive loads 223 Mean (KN/m^2 ) Mean of values (KN/m^2 ) Characteristic all values (KN/m^2 ) BH1 BH2 ...

For Figure 4.6 gives 0.5, and for L/B 10/0.35 29, the length factor 1.0, giving 0.5. Ultimate shaft resistance 0.5  110  4  0 ...

a closed end into a deep deposit of normally consolidated marine clay. The undrained shearing strength–depth profile of the clay ...