通过岩石宏观与细观断裂力学的理论与实验分析和断裂岩体破坏三维可视化数字模拟观察，研究裂隙岩体的复合断裂破坏与强度破坏受不同工程地质环境下加载边界条件控制的规律，以及受其自身局部非均匀强度和裂隙性状等因素制约的机理，研究岩体断裂破坏与强度破坏的共生规律及其相互转变的过程，探索工程地质稳定性评价的岩体断裂与破坏分析新方法。

The fracture and strength failure of many kinds of rock mass are taken place simultaneously in their instability and failure. It is one of the difficult problems in the world during analyzing the stability and safety of geological engineering. This program has studied the problem in 5 respects. (1) Carry on systemic research and re-cognition to the fracture behavior in the process of rock mass failure. In the same time, the method of clustering analysis is used to study the deformation-failure style of rock slope according to its degree controlled by fracture failure. And new fracture criterions that can be used for dividing the zone of rock mass fracture and strength failure are proposed. (2) Under different loading boundary conditions and varies crack distributing characters, through a lot of simulating test, numerical and theoretical analyses on the fracture and strength failure of the multicracked rock mass, new understanding has been reached on its macro anis tropical parameters of strength and deformation. (3) With the macro-micro experimental investigation and visualized numerical analyses of rock non-homogeneous effect on its strength and fracture failure, it is positively suggested that rock strength failure can be divided into rock medium failure and rock structure failure. （4）Further study on the mechanism of rock fracture has been carried out. The comparison between mode Ⅱ and mode III fracture of rock and the cantilever simulation of modeⅠrock fracture by three-segment-line constitution model revealed a new mode of spatial rock fracture and get the conclusion that the macro-failure mechanism is similar to its micro-failure mechanism and there are also some strength damage and strain softening during unloading. (5) For continuing a thorough study of this program in the future, many frontal research fields are involved such as three-dimension rock modeling, three-dimension visualization, information technology of decision-making in optimizing geological prospecting method, etc. The above results have mostly recognized by the internal and external important publications. A systematic understanding and a preliminary analysis method have been basically formed to the coexistence mechanism of fracture and strength failure of rock mass. They have established a solid foundation to investigate a new advanced analysis method of rock mass stability in geologic engineering.