非线性破坏准则下浅埋隧道的稳定性分析  

Stability Analysis of Shallow Buried Tunnel Under Nonlinear Failure Criterion

作　　者：傅鹤林[1] 常小兵 胡凯巽 FU Helin;CHANG Xiaobing;HU Kaixun(School of Civil Engineering,Central South University,Changsha 410075,Hunan,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《华南理工大学学报（自然科学版）》2024年第7期107-118,共12页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51978668)。

摘　　要：隧道围岩压力值是浅埋隧道设计计算的重要参数。为进一步提高围岩压力计算结果的可靠性,以传统浅埋隧道坍塌模型为基础,提出了圆弧滑移面破坏模式,同时基于非线性Mohr-Coulomb破坏准则,运用极限分析上限法推导了地震力作用下浅埋隧道围岩压力的计算公式,验证了计算结果的可靠性,并对影响因素进行了探讨。与实际工程和已有成果的对比分析证明了理论公式具有较高的可靠性和准确度。研究还发现:围岩压力受非线性系数和初始粘聚力的影响较为显著,非线性系数越大、初始粘聚力越小,围岩压力越大;随着待定参数K(水平围岩压力与竖向围岩压力的比值)的减小,水平围岩压力减小,竖向围岩压力增大;地震力对围岩压力的影响不容忽视,竖向地震力单独作用对围岩压力的影响最大,水平和竖向地震力共同作用的影响次之,而仅有水平地震力作用的影响最小。随着水平与竖向地震力系数的增大,围岩压力也在增大。分析结果对于大部分的隧道,尤其是易受地震影响的浅埋隧道研究具有较高的参考价值。The pressure value of tunnel surrounding rock is an essential parameter for shallow buried tunnel design and calculation.In order to further improve the credibility of the surrounding rock pressure calculation results,the paper proposed a circular slip surface failure model based on the traditional shallow buried tunnel collapse model.Based on the nonlinear Mohr-Coulomb failure criterion,the limit analysis upper bound method was applied to derive the formulae for calculating the pressure in shallow buried tunnel surrounding rocks under the action of seismic forces.The credibility of the calculation results was verified and the influencing factors were discussed.The high credibility and accuracy of the theoretical formula was proved through comparing the results with field engineering and existing results.It also finds that the pressure of the surrounding rock is more significantly influenced by the nonlinear coefficient and the initial cohesion;the larger the nonlinear coefficient and the smaller the initial cohe-sion,the greater the surrounding rock pressure.As the parameter to be defined K(ratio of horizontal surrounding rock pressure to vertical surrounding rock pressure)decreases,the horizontal rock pressure decreases and the verti-cal rock pressure increases.The influence of seismic forces on the pressure of the surrounding rock cannot be ig-nored.The surrounding rock pressure is most affected by the vertical seismic force alone,followed by the horizontal and vertical seismic force working together,and least affected by the horizontal seismic force alone.As the horizon-tal and vertical seismic force coefficients increase,the surrounding rock pressure also increases.The results of the study are of high reference value for the study of most tunnels,especially shallow buried tunnels that are susceptible to seismic effects.

关 键 词：浅埋隧道 围岩压力 非线性破坏准则 上限定理 拟静力法 圆弧滑移面 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]