冻结岩体单裂隙应力场分析及热-力耦合模拟

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.%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 the 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.