Reliability assessment of pile base resistance

Abstract

A reliability of pile resistance is investigated. It is assumed that parameters of soil resistance Rm, that of pile cross-sectional properties A, that of design model error ΔR, that of external actions described via dead loads VG, variable loads VQ and that of calculation errors ΔE are statistically distributed values. Statistically distributed data of some above mentioned parameters e.g. are obtained by processing the cone penetration tests (CPT), other taken from the published investigations, as e.g. of external actions. A method for evaluating resistance codified resistance is described. Subsequently the method is realized for axially loaded pile, namely for obtaining the design resistances, the resistance resource, the reliability index. Proposed method is illustrated for actual case: design of multifunctional complex for sport and relaxation at Dubysos street 10 in Klaipėda, Lithuania. Properties of strata for piles design are given, namely description of soils and their statistically distributed properties, pile resistance calculations, identifying characteristic properties of soil actions. Combinations of partial factors for investigated design approaches are presented. They involve the limit states of collapse and large deformations of pile resistance for axially loaded piles. A bearing capacity of piles’ resistances’ and reliability index of pile resistance are determined. Static tests in situ have been carried out for above described case. Processing of the test data yielded the following results: a change of testing pile relative stabilization time versus a change of relative stabilization loading; that of a relative stabilization period for certain loading level. The measured and the calculated characteristic bearing capacities of piles for above mentioned complex for sport and relaxation are presented.