非均质和各向异性土质浅埋隧道支护力研究

发布时间：2018-01-07 02:15

本文关键词：非均质和各向异性土质浅埋隧道支护力研究　出处：《湖南大学学报(自然科学版)》2017年07期 　论文类型：期刊论文

【摘要】：针对土体的非均质和各向异性,以土质浅埋隧道为例,采用极限分析上限法和可靠度方法研究隧道支护力的大小.结果表明,土体非均质和各向异性对支护力的影响程度取决于隧道的埋深.当埋深小于15m时,围岩的自稳能力较差,土体非均质和各向异性的影响不能明显地体现出来,支护力主要随埋深的增大而增大;当埋深大于20 m时,围岩的自稳能力较强,支护力随土体非均质和各向异性的增大发生明显变化,埋深越大,土体非均质和各向异性对支护力的影响越强.可靠度研究表明,非均质和各向异性参数的分布及变异系数的大小对支护力的影响较大,对数正态分布时影响更为明显.建议在土质浅埋隧道设计时,务必考虑土体的非均质和各向异性,防止保守支护增加工程成本或支护力不足引起隧道坍塌.
[Abstract]:Aiming at the heterogeneity and anisotropy of soil mass, the limit analysis upper limit method and reliability method are used to study the magnitude of tunnel support force, taking shallow soil tunnel as an example. The influence of heterogeneity and anisotropy on the supporting force depends on the depth of the tunnel. When the buried depth is less than 15m, the self-stability of surrounding rock is poor. The influence of heterogeneity and anisotropy of soil is not obvious, and the support force increases with the increase of buried depth. When the buried depth is more than 20 m, the self-stability of surrounding rock is stronger, and the support force changes obviously with the increase of heterogeneity and anisotropy of the soil, and the deeper the buried depth is, the greater the buried depth is. The study of reliability shows that the distribution of heterogeneity and anisotropy parameters and the magnitude of coefficient of variation have greater influence on the support force. It is suggested that the heterogeneity and anisotropy of soil should be taken into account in the design of shallow buried tunnel in order to prevent the tunnel collapse caused by the increase of engineering cost or insufficient supporting force.
【作者单位】：中南大学资源与安全工程学院;
【基金】：国家自然科学基金青年基金资助项目(51404303) 中南大学中央高校基本科研业务费专项资金资助项目(2015zzts084)~~
【分类号】：U455.7
【正文快照】： 大量试验研究表明,受天然沉积及后期加载等因素影响的土体,其黏聚力往往表现出显著的非均质性和各向异性[1-4].土体的非均质性一般与埋深有关,各向异性则与主应力的方向和破坏面的位置有关.岩土工程的稳定性与土体的抗剪强度指标息息相关,因此,非均质和各向异性对土体的影响成

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