初始损伤条件下地铁管片力学特性试验研究

发布时间：2018-03-28 18:59

本文选题：盾构隧道　切入点：初始损伤　出处：《隧道建设》2017年07期

【摘要】：为了解初始损伤对盾构隧道衬砌管片力学特性的影响,基于6组具有初始损伤的盾构隧道衬砌管片进行足尺试验研究。在考虑初始损伤位置以及初始损伤位置处钢筋有效面积减小等因素的情况下,对试件破坏过程、破坏模式、极限承载力、变形规律以及初始裂缝扩展机制进行了研究和分析。试验结果表明:初始损伤的存在对盾构隧道衬砌管片的极限承载能力影响不大,但对其正常使用功能影响很大;初始损伤位置处钢筋有效面积减小不仅影响盾构隧道衬砌管片的正常使用功能,更大大降低了其极限承载能力;增加轴力会削弱初始损伤对盾构隧道衬砌管片的不利影响;初始损伤在加载点比在跨中对盾构隧道衬砌管片更不利;初始裂缝基本沿径向或偏向跨中方向直线扩展。相关研究结果可为建立服役期间盾构隧道衬砌结构健康评估与预知理论、以及进一步开展损伤缺陷盾构隧道数值模拟和极限承载力分析提供借鉴和参考。
[Abstract]:In order to understand the effect of initial damage on the mechanical properties of shield tunnel lining segments, Based on the full-scale experimental study of six groups of shield tunnel lining segments with initial damage, considering the initial damage location and the reduction of the effective area of reinforcement at the initial damage position, the failure process and failure mode of the specimen are studied. The ultimate bearing capacity, deformation law and initial crack propagation mechanism are studied and analyzed. The experimental results show that the existence of initial damage has little effect on the ultimate bearing capacity of shield tunnel lining segments. But it has a great influence on its normal use function. The reduction of effective area of reinforcement at the initial damage position not only affects the normal use function of shield tunnel lining segment, but also greatly reduces its ultimate bearing capacity. The increase of axial force will weaken the adverse effect of initial damage on shield tunnel lining segment, and the initial damage will be more disadvantageous to shield tunnel lining segment at loading point than in the middle span. The initial crack extends in a straight line along radial or skew direction across the Chinese side. The relevant research results can be used to establish the theory of health assessment and prediction of shield tunnel lining structure during service. It also provides reference and reference for further numerical simulation and ultimate bearing capacity analysis of shield tunnel with damage defects.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;
【基金】：国家重点基础研究发展计划(“973”计划)项目(2011CB013800)
【分类号】：U231.3;U451.5

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