新近系泥岩隧道初期支护受力特性研究

发布时间：2018-07-11 15:52

本文选题：泥岩 + 变形　；参考：《铁道标准设计》2017年06期

【摘要】：富水区泥岩隧道开挖后经常出现支护结构大变形乃至开裂现象,影响隧道的施工和长期运营安全。为掌握新近系泥岩隧道支护结构和围岩的变形动态,开展相应的室内试验与现场监控量测以及数值模拟。采用室内试验方法获得泥岩的物理力学参数;通过现场监测方法得到围岩压力、钢拱架应变;采用数值模拟的方法获得泥岩软化前、后拱顶及拱脚沉降量、围岩压力、径向位移值的大小。研究结果表明:泥岩呈弱崩解性,且具有一定膨胀性,是导致围岩变形持续时间较长的主要原因;多数测点钢拱架弯曲,导致初期支护承载力不足,进而引起初衬混凝土掉块脱落;泥岩软化后,隧道同一位置处拱顶、拱脚沉降量、围岩压力、径向位移值均远大于泥岩软化前的数值,泥岩遇水软化是导致隧道支护结构产生大变形的原因之一。研究方法和结论对新近系泥岩隧道的设计和施工有一定的参考价值。
[Abstract]:Large deformation and even cracking of supporting structure often occur after excavation of mudstone tunnel in water-rich area, which affects the safety of tunnel construction and long-term operation. In order to understand the deformation dynamics of support structure and surrounding rock of Neogene mudstone tunnel, laboratory tests, field monitoring measurements and numerical simulation are carried out. The physical and mechanical parameters of mudstone were obtained by laboratory test method; the surrounding rock pressure and strain of steel arch frame were obtained by field monitoring method; the settlement of the arch roof and arch foot before and after mudstone softening and surrounding rock pressure were obtained by numerical simulation method. The magnitude of the radial displacement. The results show that the mudstone is weakly disintegrating and expansive, which is the main reason for the long time of surrounding rock deformation, and the bending of steel arch frame at most measuring points leads to insufficient supporting capacity at the initial stage. After the mudstone softens, the arch roof, arch foot settlement, surrounding rock pressure and radial displacement of the tunnel at the same position are far greater than the values before the mudstone softening. Mudstone softening is one of the causes of large deformation of tunnel support structure. The research methods and conclusions have certain reference value for the design and construction of Neogene mudstone tunnel.
【作者单位】：甘肃省道路桥梁与地下工程重点实验室;兰州交通大学土木工程学院;中铁第一勘察设计院集团有限公司;
【基金】：国家自然科学基金(41562013) 长江学者和创新团队发展计划(IRT1139) 甘肃省基础研究创新群体资助(145RJIA332)
【分类号】：U455.7

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