盾构管片裂损成因分析及结构安全性评价

Causes analysis and safety evaluation of cracking shield segment

依托实际工程,通过现场调查、跟踪监测和数值模拟的方法,对盾构管片施工过程中出现裂损的成因以及裂损后管片结构的安全性进行具体分析。研究结果表明:依托工程中漏水漏沙等水土流失导致管片背后岩土体支撑减弱,是引起管片结构应力集中进而出现局部裂损的主要原因。经洞内外注浆加固处理和管片结构局部修复后,未见新的裂缝发展,各项监测指标亦趋于稳定,管片结构是安全的,且能够满足后续工序安全施工的需要。采取的应急处理措施是有效的,可为类似情况参考。

According to the actual project, the causes analysis and safety evaluation of cracking shield segment were conducted by field investigation, tracking monitoring and numerical simulation methods. The results indicate that the main cause of shield segment crack is the water and soil loss induced by leakage, which leads to weaken the support of rock and earth mass at back of the segments. No new crack appears and monitoring indexes tend to stabilize after grouting inside and outside the tunnel, and repairing the cracking segments. And the segment structure is safe and can satisfy the subsequent handling needs. Therefore, the measurements are reliable and can provide reference for similar condition.