雪峰山隧道进口段仰拱填充结构开裂原因探讨

发布时间：2018-05-08 00:06

本文选题：仰拱底板 + 开裂　；参考：《地下空间与工程学报》2015年01期

【摘要】：向莆铁路雪峰山隧道进口段仰拱底板填充结构施作后出现大量未贯通的"V"字型裂缝。通过对衬砌结构受力状态分析发现,若只考虑围岩压力,不会导致仰拱底板填充结构出现裂缝;而考虑围岩压力与水压力共同作用时,最大主应力极值出现在填充结构上部靠近隧道轴线位置,为拉应力,且最大主应力极值会大于素混凝土的极限抗拉强度,会产生拉裂缝。通过现场水压力试验验证了作用在仰拱中心水压力值较大,而两侧水压力值相对较小的结论,作用在仰拱填充结构上的水压力是导致其开裂的主要原因。因此,对于处在地下水位线以下的隧道不但要考虑衬砌背后排水系统畅通,也要考虑设置隧底排水措施,以降低作用在隧底结构上的水压力,从而减少类似隧道病害出现。
[Abstract]:A large number of unconnected "V" type cracks appeared in the inlet section of the inlet section of the Xuefeng Mountain Tunnel of the Putian railway. Through the analysis of the stress state of the lining structure, it is found that if only the pressure of the surrounding rock is considered, it will not lead to the cracks in the filling structure of the invert floor, and the maximum principal stress is considered when the pressure of the surrounding rock and the water pressure are considered together. The upper part of the filling structure is near the axis of the tunnel, which is the tensile stress, and the maximum principal stress maximum will be greater than the ultimate tensile strength of the plain concrete, and the tensile crack will be produced. Through the field water pressure test, it is proved that the value of the water pressure in the center of the inverted arch is larger and the water pressure on both sides is relatively small, which is used in the inverted arch filling structure. Water pressure is the main cause of cracking. Therefore, the tunnel under the underground water line should not only consider the smooth drainage system behind the lining, but also consider setting the tunnel bottom drainage measures to reduce the water pressure on the tunnel bottom structure, thus reducing the appearance of similar tunnel diseases.

【作者单位】：中铁十八局集团有限公司;中铁西南科学研究院有限公司;
【基金】：中铁十八局自主立项课题中国中铁股份有限公司科技开发计划课题(2013-重大-9)
【分类号】：U457.2

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