Theoretical analyses of rock socketed piles

Theoretical analyses of pile socket behaviour have been used to illustrate the effects of various assumptions frequently made in socket design. The most important assumption is that of the nature of pore water drainage during loading, and phi = 0 behaviour is significantly different from c - phi or c-phi joint behaviour. Elastic solutions have been extended for a new design method, and expanded to include the important two layer case. Some computational difficulties remain, particularly regarding stresses at the pile extremities, and further work - including non linear elastic analyses for economy and more accurate parameter modelling - is in progress. Correct simulation of joint behaviour is also a complex laboratory and computational problem, but interim results are promising. In spite of these difficulties, it should be added that the programme has been used with great success in aiding decision making for a wide range of practical problems, including piles in layered rocks with weak zones beneath the base, piles in thin, jointed rock layers overlying clay and field tests for rock parameter determination.