The Research On Reliability Of Pre-Consolidation Pile

This paper is part of the research on reliability of supporting structure by Professor Luo Shuxue.In resent years, along with the widely use of Mechanical Excavation in railway construction, the Pre-Consolidation Pile, which is an approach of slope pretreatment, will also be applied. This paper carried out a system research on reliability of Pre-Consolidation Pile, and let the design method of Pre-Consolidation Pile transfer from permissible stress-method to partial coefficient method. This is the preparation for the work of revising supporting structure design norms of railway embankment. At the same time, it also lay the foundation for the in-depth study on reliability of Pre-Consolidation Pile.Following contents are discussed in this paper: The 22 Pre-Consolidation Piles embed in soil foundation and the 18 ones embed in rock foundation are selected for the study. This paper uses calibration method as research method to confirm overall reliability standard of the existing structural design and reliability index of the design of the future. According to three failure models of Pre-Consolidation Pile (flexural failure, sheared failure and soil failure), three limit state equations are respectively developed after consulting lots of reference and deliberate analysis. Random variable and statistics parameters are fixed after consulting lots of theoretical analysis and specific test.By deep studies in this paper, following conclusions are drawn: (1) The C program of Monte-Carlo method is developed and computed to express the safety level of Piles in form of reliability index. (2) The Pre-Consolidation Pile checking expressions are presented based on reliability theory. (3) Resistance partial coefficient and action partial coefficient are obtained by using common separating method. Subsequently, expressions of design and checking computations containing partial coefficients are gained. Thus, partial coefficient design method is gained. The above-mentioned study will provide an important theoretical basis for Pre-Consolidation Pile engineering design by reliability method and a good reference value.