多场耦合作用下岩体裂隙扩展演化关键问题研究

裂隙岩体热-水-应力（THM）耦合是目前研究的热点和难点。首先总结了裂隙岩体多场耦合的机制、模型、方法及研究内容，并通过分析裂隙对THM耦合的重要控制作用，提出了在THM耦合中考虑裂隙网络扩展演化及模拟的关键问题，同时指出了研究的3个关键点：（1）建立考虑裂隙网络演化的耦合模型；（2）裂隙扩展的数值模拟方法；（3）THM耦合及岩体变形、失稳全过程的数值模拟算法。随后通过对模拟多场耦合和裂隙扩展数值方法的归类比较，重点论述了目前适用于模拟多场耦合下裂隙扩展模拟的各种数值方法（包括有限单元法、无单元法、单位分解法、离散单元法、岩石破裂过程分析方法和数值流形方法）的优缺点，并通过对比研究，推荐采用数值流形方法（NMM）来实现对关键问题的模拟研究。最后，对研究思路和难点进行了初步探讨。

Research on critical problem for fracture network propagation and evolution with multifield coupling of fractured rock mass

It is hot and difficult point that research on thermo-hydro-mechanical (THM) coupling for fractured rock mass at present. Firstly, the research status of mechanism, models, numerical simulation methods and contents for multifield coupling of fractured rock mass are summarized. Meanwhile, the significant effect on THM coupling of fractures is analyzed. As a result, the critical problem considering the fracture network propagation and its simulation during the THM coupling is proposed. Furthermore, 3 critical points are pointed out: (1) building the THM coupling model which can consider the fracture network propagation; (2) selecting numerical simulation method of simulating fracture propagation; (3) proposing the simulation algorithm for THM coupling and the whole process of rock mass from deformation to collapse. Then, the numerical methods for simulating coupling and fracture propagation are classified and compared; therefore, the various numerical methods, including finite element method, element-free method, partition of unity method, discrete element method, rock fracture process analysis method and numerical manifold method, are discussed thoroughly and particularly, from the advantages and disadvantages. Following, the numerical manifold method (NMM) is recommended for solving the critical problem. Finally, some ways and difficulties of the work are discussed preliminarily.