冻结岩体单裂隙应力场分析及热ndash;力耦合模拟(文本).doc

冻结岩体单裂隙应力场分析及热–力耦合模拟 刘泉声1，21 (1. 武汉大学土木建筑工程学院 水工岩石力学教育部重点实验室，湖北 武汉 430072； 2. 中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室，湖北 武汉 430071) 摘要：我国寒区分布面积广泛，岩体冻融损伤问题涉及低温环境下温度场、渗流场和应力场的耦合，严重威胁着寒区岩体工程的安全稳定。在考虑水分迁移的条件下，以水冰相变为切入点，结合断裂力学、弹塑性力学理论，分析冻胀荷载作用下饱和岩体裂隙应力场分布规律与尖端应力强度因子。考虑温度对冻结率的影响，采用等效热膨胀系数法模拟冻胀荷载，运用FLAC3D软件建立单裂隙冻胀热–力耦合模型，编制FISH程序进行计算，得出冻胀作用下裂隙附近应力场分布，并与理论值进行对比分析。 关键词：岩石力学；裂隙岩体；相变；冻胀力；应力强度因子 中图分类号：TU 45 文献标识码：A 文章编号：1000–6915(2011)02–0217–07 ANALYSIS OF STRESS FIELD AND COUPLED THERMO-MECHANICAL SIMULATION OF SINGLE-FRACTURE FREEZED ROCK MASSES LIU Quansheng1，2，KANG Yongshui2，LIU Xiaoyan1 (1. Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Ministry of Education，School of Civil Engineering and Architecture，Wuhan University，Wuhan，Hubei 430072，China；2. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China) Abstract：There is a vast area of cold regions distributed in China. The problems that freezing-thawing damage will seriously threaten the stability of rock engineering need to be solved，which involve thermo-hydro- mechanical(THM) coupling problem at a low temperature. Considering the migration of water and phase transition，the distributions of stress field and stress intensity factor near the fracture are analyzed by using the theories of fracture mechanics and elastoplastic mechanics. Considering the effect of temperature on freezing ratio，the frost load is simulated by method of equivalent coefficient of thermal expansion. Finally，the model for freezing fracture is established with FISH program to simulate the stress field near the fracture；and comparisons between numerical and analytical results are made. Key words：rock mechanics；fractured rock mass；phase transition；frost force；stress intensity factor  1 引 言 我国寒区分布面积广泛，在寒区工程建设和资源开采过程中，会遇到很多岩体工程冻融损伤破坏的难题，如寒区隧道常常出现衬砌开裂、剥落、挂冰及洞口处热融滑塌等病害，严重威胁着围岩的安全稳定[1]。规范[2]规定，最冷月平均温度低于－15 ℃和受冻害影