A numerical analysis has been conducted to evaluate the effect of confining pressure on the damage evolution and the fracture process of brittle rock materials by using the rock failure process analysis code (RFPA2D). A fractal dimension D associated with material damage and a damage variable v are defined to describe the damage process of the specimen subjected to tensile or compressive load. We find that the spatial distribution of microfractures is fractal and has very good statistical self-similarity in the specimen under different confined conditions. The fractal dimension D increases progressively with loading. Meanwhile, the damage variable v develops from 0 to 1, and the specimen failure is characterized by the critical damage variable vc with 0.4<vc<0.8. The initial damage is delayed by the confining pressure. The confining pressure plays an important role in the mode of rock failure in numerical simulations. The tensile microfractures dominate near the brittle splitting of the specimens under no and low confining pressure. Conversely, a few tensile microfractures appear in the ductile shear failures of the specimens under immediate or high confining pressures. The tensile microfractures run through all failure processes in the specimen under uniaxial tensile loading. The stress-strain curves are also obtained in numerical simulation. The results show that the specimen is strengthed by the confinement and fails according to Mohr-Coulomb failure criterion.

利用RFPA2D对岩石在不同围压下损伤破坏演化过程进行了数值模拟，基于岩石损伤定义分形维数以描述试样在各种加载条件下微破裂的演化过程。计算结果表明：分形维数和损伤变量随着荷载的增加逐渐增大，岩石的起始损伤随着围压增加而被延迟，试样强度随着围压的增加而增加，其宏观破坏符合Mohr-oulomb破坏准则。

基于岩石变形过程中损伤局域化现象，根据岩石材料随机性的特点，通过二维网络系统损伤演化的有限元数值模拟发现：岩石微破裂在损伤演化过程中显示出从均匀随机的无序逐渐向局域化的有序转化特征，不论微破裂如何演化，最终都诱致岩石网络系统产生突变破裂现象。用岩石微破裂与声发射具有一致性的假设，模拟出岩石破裂过程中声发射空间分布的规律。

针对脆性岩石细观强度非均匀、离散性特征，利用重正化群理论建立了岩石临界破坏重正化模型，系统研究了岩石宏观临界强度和细观强度的定量关系，采用条件概率方法处理模型中细观单元间的应力转移，从而求得岩石临界破裂时的临界概率P*，着重研究了岩石均质度与岩石峰值强度的理论关系。此外，利用岩石破裂过程分析程序（RFPA）模拟了岩石单轴压缩下细观破裂演化至宏观破裂的全过程。研究结果表明，数值模拟和重正化群得到的岩石峰值强度十分吻合。

Based on the phenomenon that acoustic emissions (AE) generated by rock mass increase suddenly because of underground excavation, time sequence of AE rate in rock failure has been discussed by using statistical damage theory. It has been demonstrated that how the influence of confining pressure on the deformation behavior and AE characteristics in rocks can be inferred from a simple mechanics model. The results show that loading confining pressure sharply brings out increasing of AE. On the other hand, few AE emits when confining pressure is loaded sharply, and AE occurs again when axial pressure keeps on increasing. These results have been well simulated with computer and show close correspondence with directly measured curves in experiments.

运用损伤力学的基本原理，阐述了综放开采顶煤在支承压力作用下损伤演化与冒放性之间的关系。利用细观统计损伤力学建立了损伤参量的计算模型，把顶煤损伤参量作为冒放性指标加以研究，并讨论了开采深度、煤层强度、原始裂隙和水平应力对顶煤冒放性的影响，其理论结果和现场实际相吻合。

针对由于地下开挖引起的岩石声发射率突增及最小主应力减小可能引起地震等地质现象，利用统计损伤理论对岩石破裂过程中声发射率的时间序列特征，特别是三维应力下岩石的快速加卸围压对声发射的影响进行了理论探讨。结果表明: 三维应力下岩石快速卸围压,促使声发射率突增，而在一定范围内快速增加围压，声发射并不发生，只有增加一定轴压,才会有声发射的产生，这些结果在计算机上得到了很好的模拟，并与实验结果相吻合。

针对大同矿务局忻州窑矿 8911面综放开采煤岩变形破坏的全过程，利用岩石力学数值分析方法对放顶煤三维采场的顶煤、顶板活动进行了系统的研究，得到了三维模型的应力、变形及单元破坏数值分析结果。研究表明：大同矿务局煤层强度较高，在支承压力作用下难于破碎，需进行弱化处理后才能有效放出。综采放顶煤过程中，支承压力具有明显的分区特征，顶煤的始动点就是支承压力峰值位置，位于煤壁前方5～7m处，并得到现场实测结果的验证。

利用连续介质损伤力学方法，通过岩石微元体强度的Weibull 统计分布和库仑准则假定，建立了一个简明的岩石三维各向同性损伤模型及弹脆性本构方程。探讨了岩石试样试验的应力-应变全过程特征、损伤演化规律、岩石试样加载的围压效应以及卸荷破坏下强度及脆化特征，理论与试验结果表明，卸载破坏比加载破坏表现得更为脆性、更突然。

基于加载体刚度对岩石试样产生声发射率时间序列的影响，利用统计细观损伤力学对加载体和岩石试样组成的简单力学模型产生的声发射进行了理论分析，推出了具有围压作用的应力-应变全过程关系，并利用计算机对全过程进行了仿真模拟。结果表明，加载体刚度的变化通过影响岩石试样变形速率的方式来参与影响岩石试样声发射率的时间序列，理论结果和实验值吻合较好。