中文摘要：

水下盾构隧道管片衬砌结构病害的防治是一个公认的难题,揭示管片衬砌结构破坏、失稳的机理显然对病害的科学治理具有很强的指导意义。采用模型试验方法,通过超载的形式对水下盾构隧道管片衬砌结构从材料细观损伤到结构宏观局部破坏再到结构整体失稳的整个渐进性破坏失稳过程进行了系统研究。将大型水下盾构隧道管片衬砌结构渐进性破坏过程划分为初始弹性阶段、局部损伤阶段、宏观破坏阶段和整体失稳阶段四个阶段,并给出了各阶段管片衬砌结构的力学行为特性;探明了盾构隧道管片衬砌结构失稳临界点,并以关键点位移与隧道外半径比值的形式给出了失稳临界建议值;通过对声发射数据的分析,揭示了管片衬砌结构破坏过程的渐进性特性,并获得了声发射事件出现的频率与幅值分布随外部荷载的变化规律;分析了管片衬砌结构宏观裂纹的出现及扩展规律,并通过最终破坏形态分析了造成管片衬砌结构整体失稳的关键部位的空间分布以及破坏形式。

英文摘要：

The prevention and treatment of the structural diseases of lining segments used in the underwater shield tunnels is a commonly recognized difficult problem. To achieve the scientific treatment of diseases,revealing the progressive failure mechanism of lining segment structure is essential. By the model test,the complete progressive failure process of lining segment structure used in the underwater shield tunnels is systematically studied. The progressive failure process can be divided into four stages,namely the initial elastic stage,local damage stage,macroscopic failure stage and overall failure stage,and then the mechanical characteristics of lining segment structure in each stage are elucidated.The critical failure points of lining segment structure under different conditions are ascertained,and the recommended values of critical failure state are given according to the ratio of the maximum displacement of key points to the outer radius of shied tunnel. Based on the analysis of acoustic emission data,the progressivity characteristic of the failure process of lining segment structure is revealed,and the variation laws of the occurrence frequency and amplitude distribution of acoustic emission events with external loads are also achieved. The occurrence and propagation laws of macroscopic cracks in lining segment structure are analyzed,and based on the ultimate failure pattern of lining segment structure the spatial distribution and failure mode of the key parts which causes the overall failure of lining segment structure are also analyzed.