通缝拼装盾构隧道结构极限承载力的足尺试验研究

Experimental investigation on the ultimate bearing capacity of continuous-jointed segmental tunnel linings

针对轨道交通通缝拼装的盾构隧道结构的承载性能,进行结构的足尺静载试验。具体介绍试验方案和加载方案的设计,提供结构变形、管片裂缝、接缝变形和连接螺栓受力的发展情况以及破坏过程等试验结果;对结构的承载性能和破坏机理进行分析。足尺试验研究表明:试验结构的破坏由不同部位接缝混凝土先后受压破坏形成,属梁铰机制;管片接缝是隧道极限承载力的关键断面;周边卸载工况下结构的承载力安全系数比顶部超载工况小,对盾构隧道结构的承载更为不利。

Full-scale static loading tests were conducted on the ultimate bearing capacity of continuous-jointed segmental tunnel linings. The design of testing linings and loading schemes were firstly introduced. The test results,including the evolution of deformation,segment crack,joint opening and connecting bolt stress,were achieved. The bearing capacity and failure mechanism of tested linings were discussed and analyzed. It was found that the failure of tested linings was caused by the strength failure of its joints,implying that the joints should be taken with great cares during the structural design. Compared with the overload case,the unloading case is often more detrimental to the bearing capacity of tunnel linings.