摘要
针对非静水压力作用下圆形巷道的非圆塑性区边界线求解,首先通过类比提出围岩弹性区应力的简洁复变函数,基于理想弹-塑性模型和Mohr-Coulomb准则并利用围岩弹塑性交界线处的应力连续条件,建立了巷道塑性区半径的复变函数实用解答,其次采用弹-脆-塑性模型和统一强度理论以考虑围岩强度的峰后脆性下降与中间主应力效应,推导了巷道塑性区半径的复变函数扩展解答,最后给出所得解答的适用条件,并与文献理论解答和实测结果进行对比。研究结果表明:所得复变函数实用解答具有显式解析表达和易于计算分析等优点,其正确性与精度得到文献摄动解和高精度复变函数解的充分性验证;所得扩展解答保留了原实用解答的所有优点,能合理描述围岩强度的峰后脆性下降与中间主应力效应而工程应用前景广阔,与深埋巷道实测松动圈吻合良好。
In order to address the non-circular plastic boundary of rock circular tunnels under non-hydrostatic pressures,a simple complex variable function for the stress in an elastic zone is firstly introduced by using the analogy method.Based on the elastic perfectly-plastic model and the Mohr-Coulomb criterion,a practical solution for complex variable function for the radius of tunnel plastic zone is then derived under the stress continuity at the elastic-plastic boundary of surrounding rocks.Additionally,an extended solutions for complex variable function for the radius of tunnel plastic zone is proposed by adopting the elastic-brittle-plastic model and the unified strength theory to take into consideration both the post-peak brittle decrease and the effect of the intermediate principal stress of rock strength.Finally,the application conditions for the proposed solutions are provided,and they are compared with the available theoretical solutions and the measured data in the literatures.The results show that the practical solution for complex variable function has the advantages of explicitly analytical formulation as well as convenient calculation and analysis,whose validity and accuracy are sufficiently demonstrated by the perturbed solution and high-precision solution for complex variable function in the literatures.The extended solution retains all the advantages of the original practical solution and has good consistency with the measured loosening depth of a deep tunnel.Moreover,the extended solution has a broad application prospect due to the fact that it reasonably accounts for the post-peak brittle decrease and the effect of the intermediate principal stress of rock strength.
作者
张常光
李宗辉
孟祥忠
王晓轮
李天斌
ZHANG Changguang;LI Zonghui;MENG Xiangzhong;WANG Xiaolun;LI Tianbin(School of Civil Engineering,Chang'an University,Xi'an 710061,China;Stake Key Laboratory of Geohazard Prevetion and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2023年第12期2438-2444,共7页
Chinese Journal of Geotechnical Engineering
基金
地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2020K022)
长安大学中央高校基本科研业务费专项资金项目(300102282206)。
关键词
非静水压力
巷道塑性区半径
复变函数
峰后脆性
中间主应力效应
non-hydrostatic pressure
radius of tunnel plastic zone
complex variable function
post-peak brittleness
effect of intermediate principal stress
