摘要
针对非线性条件下深埋隧道开挖面稳定性问题,采用多切线技术分段线性近似Power-Law(P-L)准则,基于极限分析上限定理,构建1种新的开挖面多曲线圆锥破坏机构,提出1种考虑拉应力截断Tensioncut-off(T-C)效应的开挖面稳定性理论计算方法。通过与既有文献结果对比,验证所提方法的可靠性。根据反算的应力分布和破坏机构几何特点,探究不同参数条件下T-C对开挖面稳定性的影响。结果表明:(1)在线性条件下,黏聚力较大且内摩擦角较小时,T-C对开挖面临界支护力的影响较大;在非线性条件下,m的增加并不会放大T-C对开挖面稳定性的影响。(2)在抗拉强度较大时,T-C对开挖面稳定性影响较为显著,随着抗拉强度的折减,T-C控制的破坏机构尺寸逐渐减小,且顶部区域明显钝化。
To address the face stability problem of deep-buried tunnels under nonlinear conditions,using Power-Law(P-L)criterion the approximate piecewise and by multi-tangent technique,a novel multi-cone failure mechanism is developed for tunnel faces based on the kinematic limit analysis theorem.A theoretical framework considering the tension cut-off(T-C)is proposed to evaluate the stability of tunnel faces.The reliability of the proposed method is validated through comparison with that in the existing literatures.Based on the back-calculated stress distribution and geometric feature of the failure mechanism,the influences of T-C under different parameters on the stability of tunnel faces are investigated.The results indicate that:(1)under the linear condition,the effects of T-C on the critical support pressure are more significant with high cohesion and small internal friction angle.Under the nonlinear condition,an increase in the nonlinear coefficient will not exacerbate the impact of T-C on the face stability.(2)For higher tensile strength,the effects of T-C on the stability of tunnel faces are significant.As the tensile strength decreases,the failure mechanism governed by T-C gradually shrinks,and the top of the failure mechanism exhibits noticeable blunting and looks like a dome.
作者
钟军豪
CHIAN Siau Chen
李永鑫
刘明芳
陈明辉
吴振元
龙桂华
杨小礼
周德
ZHONG Junhao;CHIAN Siau Chen;LI Yongxin;LIU Mingfang;CHEN Minghui;WU Zhenyuan;LONG Guihua;YANG Xiaoli;ZHOU De(School of Civil Engineering,Central South University,Changsha 410075,China;Department of Civil and Environmental Engineering,National University of Singapore,Singapore 117576;School of Automotive and Transportation Engineering,Hefei University of Technology,Hefei 230009,China;Shenzhen Municipal Engineering Corporation,Shenzhen 518000,China)
出处
《岩土工程学报》
EI
CAS
北大核心
2025年第1期76-84,共9页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(5210081105)
安徽省自然科学基金项目(2108085QE250)
湖南省研究生科研创新项目(CX20220239)
国家留学基金项目(国家建设高水平大学公派研究生项目)。
作者简介
钟军豪(1996-),男,博士研究生,主要从事隧道开挖面稳定性和地层建模方面的研究工作。E-mail:zhongjunhao@csu.edu.cn;通信作者:周德(E-mail:210026@csu.edu.cn)。
