Abstract:The composite element method(CEM) is used to simulate the effects of strain localization bands,based on which a new trace algorithm of the propagation of strain localization bands is proposed. The softening effects within the strain localization bands are illustrated as the decrease of the material parameters,the locations and directions of all the potential strain localization bands are logged and simulated. With the rock fracture statistics technology,the failure passage can be fitted;the messages of this failure passage together with the messages of the initial grid are then used to generate the topology messages of composite elements,based on which the calculation is repeated to check the trace procedure of the strain localization propagation. The trace algorithm proposed does not request the continuity of strain localization propagation paths,and the interaction among localization band segments can be taken into account. The feasibility and reliability of the algorithm are verified by a slope example. The expectation of the algorithm in engineering practices is shown by the comparative study of the Baozhusi gravity dam project.