基坑支护体系概率极限状态设计中分项系数的研究

Study on the partial factors in the probability limit state design of the retaining system

根据受力机理，建立了支护体系按概率极限状态设计的各种工况下的失效模式；并考虑支护结构自身的特点，提出了可靠度指标目标值［β］；以此为约束条件，反算其容许最大荷载值和分项系数等，最后优化所有工况下求得的分项系数，提出了一个合理的分项系数建议值。

This paper gives all kinds of failure models in the probability limit state design of the retaining system, and presents the target value  of the reliability index. Under this binding condition, this paper calculates the permitted maxium load and partial factors. Finally, it optimizes the partial factors derived in all kinds of conditions and presents reasonable values.