加筋土挡墙结构系统的可靠性分析

Structural system reliability analyse of reinforced earth retaining wall

基于系统可靠性理论,在分析加筋土挡墙内外部稳定极限状态方程基础上,研究各失效模式的逻辑关系,建立加筋土挡墙结构系统的可靠度计算模型,并进行实例分析。研究结果表明:加筋土挡墙结构的可靠度不等于单一失效模式下的可靠度,可靠性分析时应进行结构系统可靠度计算;加筋土挡墙中单层(根)筋材的抗拉断与抗拔出破坏模式是不相容的;内部稳定性是由多根筋材的稳定性所构成,遵循k/n模型;外部稳定性的4种失效模式是混联系统,抗滑稳定性与抗倾覆稳定性是不相容关系,并与地基承载力稳定性和整体稳定性构成串联系统;局部稳定性也遵循k/n模型,加筋土挡墙的内部稳定性、外部稳定性和局部稳定性三者构成串联系统。

Based on the structural system reliability theory, the limit state fimctions of various failure modes of reinforced earth retaining wall and their logic relationships were analyzed, the structural system reliability calculation model was established and a practical project was analyzed. The results show that the reliability of a single failure modes can not indict the stability state of reinforced earth retaining wall and the structure system reliability should be analyzed; the reinforcement may be damaged by broken or pull-out, but the two failure modes are incompatible; the internal stability of reinforced earth retaining wall is the result of combined effect of multiple layers reinforcements and they follow the model of k/n. The external stability refers to four failure modes, in which the stability against sliding and overturning are incompatible, and they compose a series system with bearing capacity of foundation and the overall stability; the local stability follows the model of k/n also; and the internal stability, external stability and local stability constitute a series system.