Safety of piles in groups

Abstract

Peculiarities of external bearing capacity of piles in groups, their safety assessment principles and target values of structural safety indices are discussed. An assessment of external and internal design safeties of axially loaded single reinforced concrete piles and pile group blocks by the method of partial safety factors is analysed. Probability-based approaches and design equations for structural safety assessment and prediction of piles in groups exposed to regular and irregular variable actions are presented. The structural safety of single piles and pile group blocks as autosytems representing multicriteria failure mode is considered. It is shown that structural safety indices of autosystems may be simply calculated by the method of transformed conditional probabilities. The numerical example illustrates an inuniversality of the deterministic method of partial safety factors and a necessity of practical recommendations of the probability based design.