研究结论:(1)理论分析和实际计算结果显示，支挡结构安全系数或分项系数和可靠指标是正相关的;(2)可靠指标与支挡结构极限状态密切相关，对应不同的状态和安全预期，应采用不同分级的可靠指标;(3)基于系统工程的观点，为保持支挡结构处于同-可靠度水平，支挡结构设计检算中各分项系数应根据可靠度指标分析结果进行适当调整;(4)本文关于支挡结构可靠指标分级以及基于同-可靠度要求进行分项系数调整的观点，可直接用于指导支挡结构的设计。

Research conclusions :(1) The theoretical analysis and practical calculation results show that the safety coefficient or partial coefficient of retaining structure and reliability index are positive correlation. (2) The reliability index is closely related to the retaining structure limit state, corresponding to different status and safety forecast, the reliability index of the different classification should be adopted. (3) Based on viewpoint of system engineering, the reliability of retaining structure is maintained in the same level, each partial coefficient calculated in retaining structure design should be adjusted according to the analytical result of reliability index. (4) Reliability index classification of retaining structure in this paper and the viewpoint of partial coefficient adjustment based on same reliability requirement can be directly used to guide the design of the retaining structure.