基于统一强度理论和稳定蠕变准则的软岩巷道最优支护
Optimal Support in Soft Rock Tunnel Based on the Unified Strength Theory and Steady Creep Guideline
作者：曾开华(南昌工程学院 土木与建筑工程学院, 江西 南昌 330099;南昌工程学院 江西省水利土木特种加固与安全监控工程研究中心, 江西 南昌 330099)；杨维汉(南昌工程学院 土木与建筑工程学院, 江西 南昌 330099;南昌工程学院 江西省水利土木特种加固与安全监控工程研究中心, 江西 南昌 330099)；张常光(长安大学 建筑工程学院, 陕西 西安 710061)；戴红涛(南昌工程学院 土木与建筑工程学院, 江西 南昌 330099;南昌工程学院 江西省水利土木特种加固与安全监控工程研究中心, 江西 南昌 330099)
Author：ZENG Kaihua(Dept. of Civil Eng. and Architecture, Nanchang Inst. of Technol., Nanchang 330099, China;Jiangxi Provincial Eng. Research Center of the Special Reinforcement and Safety Monitoring Technol. in Hydraulic & Civil Eng., Nanchang Inst. of Technol., Nanchang 330099, China)；YANG Weihan(Dept. of Civil Eng. and Architecture, Nanchang Inst. of Technol., Nanchang 330099, China;Jiangxi Provincial Eng. Research Center of the Special Reinforcement and Safety Monitoring Technol. in Hydraulic & Civil Eng., Nanchang Inst. of Technol., Nanchang 330099, China)；ZHANG Changguang(School of Civil Eng., Chang'an Univ., Xi'an 710061, China)；DAI Hongtao(Dept. of Civil Eng. and Architecture, Nanchang Inst. of Technol., Nanchang 330099, China;Jiangxi Provincial Eng. Research Center of the Special Reinforcement and Safety Monitoring Technol. in Hydraulic & Civil Eng., Nanchang Inst. of Technol., Nanchang 330099, China)
收稿日期：2016-09-08 年卷（期）页码：2018,50(1):62-70
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：软岩巷道;统一强度理论;稳定蠕变准则;最优支护
Key words：soft rock tunnel;unified strength theory;steady creep guideline;optimal support
基金项目：江西省教育厅科学技术研究项目资助（GJJ151117）；江西省自然科学基金资助项目（20142BAB206001）；国家自然科学基金资助项目（51769016）；中国博士后科学基金资助项目（2016T90879）
中文摘要
巷道最优支护可以实现新奥法安全经济的最佳支护状态，根据软岩流变控制原则和统一强度理论，合理考虑中间主应力与强度准则选取的影响，推导两种稳定蠕变准则下巷道最优支护力和围岩允许最大位移的理论解答，给出公式适用条件、应用步骤，并进行两个工程实例验证，分析中间主应力、岩石长期强度及围岩抗剪强度参数等对巷道最优支护力与围岩允许最大位移的影响规律。结果表明：本文理论解答可退化为文献已有结果，具有较好的可比性；所得公式表达简洁，参数易于确定，具有良好的工程应用前景；两种稳定蠕变准则的巷道最优支护参数的变化规律一致且整体差异较小，但应力偏张量第三不变量准则相应解答的适用范围更广；中间主应力效应和强度准则选取对巷道最优支护参数的影响显著，Mohr-Coulomb准则的结果过于保守，难以发挥围岩的强度潜力；岩石长期强度是巷道最优支护设计的关键参数，围岩黏聚力相比内摩擦角对巷道最优支护参数的影响更为明显，应充分考虑岩石强度参数的变异性。所得结果可为软岩巷道的最优支护设计与施工提供理论指导和建议。
英文摘要
The optimal support of tunnel can achieve the best supporting state with both safety and economy as suggested by New Austrian Tunnelling Method (NATM).Theoretical solutions for the optimal support pressure of tunnel and the allowable maximum displacement of surrounding rock under two steady creep guidelines are presented on the basis of the controlling principle of soft rock rheology.The unified strength theory is adopted to reasonably consider the influences of both the intermediate principal stress and the chosen of strength criteria.Then,the applicable conditions and application steps about the proposed solutions are provided.Finally,these theoretical solutions are validated by two engineering cases,and the influences of a wide range of variation of parameters like intermediate principal stress,long-term strength of rock as well as shear strength of surrounding rock on the optimal support pressure of tunnel and the allowable maximum displacement of surrounding rock have been discussed.It is found that the obtained theoretical solutions in this study have good comparability and can degenerate into the available results from the literature,the expressions of the obtained theoretical solutions are concise,and the parameters involved are easy to been determined.Thus the proposed theoretical solutions have a good prospect of engineering applications.Generally speaking,the evolution of the optimal parameters of tunnel support under two steady creep guidelines is in good agreement with little differences,however the result according to the third invariant guideline of deviator stress tensor has broader applicable scope.The influences of intermediate principal stress and choosing strength criteria on the optimal parameters of tunnel support are significant,and the result of Mohr-Coulomb criterion is too conservative to make use of potential rock strength.Long-term strength of rock is a key parameter for the optimal design of tunnel support,and the cohesion of surrounding rock has a more noticeable influence than that of its internal friction angle.The variability of rock strength parameters shoud be taken into full account.The obtained results can provide a theoretical guidance to the design and construction of the optimal support in soft rock tunnel.
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