将冗余度理论引入到双排钢板桩围堰的设计中，提出双排钢板桩围堰支护体系冗余度的定义与设计方法的初步框 架。以拉杆系统的冗余度分析为例，采用拆除构件法，对其冗余度进行了定量分析。结果表明，下道拉杆的冗余度参数明显低于上道拉杆，其失效后会明显降低整个围堰支护体系的刚度、强度和稳定性，会导致整个围堰的破坏坍塌，这与工程实际相吻合。以上分析验证了冗余度理论在双排钢板桩围堰工程中适用性及可行性。

The redundancy theory is introduced into the double-row steel sheet piles cofferdam design. The preliminary framework of the definition and design of double-row steel sheet piles cofferdam supporting system redundancy are proposed. Taking the rod system redundancy analysis for example, alternate path method is adopted to quantitatively analyze for redundancy of the rod system. The results show that the redundancy parameters of lower rods are significantly lower than the upper rods; their failure can significantly reduce the stiffness, strength and stability of cofferdam supporting system; their failure even leads to the destruction of the whole cofferdam to collapse; it is consistent with the engineering practice. The above analysis verified the applicability and feasibility of the redundancy theory for double-row steel sheet piles cofferdam engineering.