考虑中主应力后对隧道围岩稳定性的影响

发布时间：2018-01-02 17:10

本文关键词：考虑中主应力后对隧道围岩稳定性的影响　出处：《中国铁道科学》2015年04期 　论文类型：期刊论文

【摘要】：在分析中主应力对隧道围岩强度影响的基础上,采用FLAC3D有限差分元软件,建立考虑中主应力的岩体强度准则本构模型,并同摩尔库伦准则相比较,研究考虑中主应力后对隧道围岩稳定性的影响。结果表明:考虑中主应力后,计算得到的岩体强度较不考虑时显著增加,当中主应力大于等于岩体抗压强度时,围岩强度提高75%~200%;若围岩服从摩尔库伦准则,则在一定数值范围内,中主应力不影响隧道中围岩的应力分布,且对拱顶沉降及塑性区也几乎没有影响;若围岩服从考虑中主应力的岩体强度准则,则随着中主应力的逐渐增大,围岩强度逐渐增大,拱顶沉降、开挖扰动范围和塑性区半径均逐渐减小。因此,在隧道侧向应力较大时,采用考虑中主应力的岩体强度准则进行数值模拟,更能准确地反应围岩的稳定性。
[Abstract]:Based on the analysis of the influence of medium principal stress on the strength of surrounding rock mass, the constitutive model of rock mass strength criterion considering medium principal stress is established by using FLAC3D finite difference element software and compared with the Moore Coulomb criterion. The effect of medium principal stress on the stability of tunnel surrounding rock is studied. The results show that the calculated rock mass strength is significantly increased when the medium principal stress is considered, and the principal stress is greater than that of rock mass compressive strength. The strength of surrounding rock is increased by 75% and 200%; If the surrounding rock obeys the Moore Coulomb criterion, the medium principal stress does not affect the stress distribution of the surrounding rock in the tunnel in a certain range, and has little effect on the settlement of the arch roof and the plastic zone. If the rock mass strength criterion with medium principal stress is taken into account, the strength of surrounding rock increases gradually with the increase of middle principal stress, the settlement of arch roof, the disturbance range of excavation and the radius of plastic zone decrease gradually. When the lateral stress of tunnel is large, the stability of surrounding rock can be more accurately reflected by using the strength criterion of rock mass considering medium principal stress.
【作者单位】：西南交通大学土木工程学院;西南交通大学交通隧道工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(51378321);国家自然科学基金青年科学基金资助项目(51208437) 中央高校基本科研业务费专项资金资助项目(SWJTU11ZT33)
【分类号】：U451.2
【正文快照】： 在深埋地下工程中,岩体一般都处于三向应力状态。隧道开挖会引起隧道周边应力的重分布,其中最大主应力σ1和最小主应力σ3均会有较大的释放,而中主应力σ2不会随着隧道掌子面的开挖而大量释放,特别是当隧道处于特殊应力构造场(如挤压地层)时,中主应力σ2会远远大于最大主应力

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