SIMULATION OF THREE-DIMENSIONAL EMBEDDED CRACKS WITH ELEMENT PARTITION METHOD
WANG Deyong1，ZHANG Zhennan1，GE Xiurun1，2
(1. School of Naval Architecture，Ocean and Civil Engineering，Shanghai Jiaotong University，Shanghai 200240，China；
2. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，
Chinese Academy of Sciences，Wuhan，Hubei 430071，China)
Abstract：The jointed rock mass contains numerous embedded cracks，their propagation have significant impact on the stability of rock mass. However，it is very hard to study the embedded crack propagation through physical experiment. But when using the numerical method，i.e. finite element method，to numerically investigate this problem，the representation of 3D interface and mesh generation with consideration of setting up joint element has been a tough problem. To provide a simple and efficient method for failure analysis of jointed rock mass，the paper employs the 3D element partition method. The 3D element partition method actually develops a four-node contact element by taking advantage of the geometry character of the tetrahedron element. When a fracture cuts through a tetrahedron element，the nodes at different sides of fracture can construct 3 or 4 contact pairs，based on which the stiffness matrix of partitioned element is derived. When using this method，the cracked body can be directly meshed regardless of geometric integrity of jointed rock mass. Thereafter，many tetrahedron elements are intersected by pre-existing fracture. For those intersected element，the partitioned element stiffness matrix is adopted whereas for the rest，the normal element stiffness matrix is adopted. This makes the simulation of jointed rock mass highly simple and efficient. The comparison between the tested and the simulated results of elliptic crack propagation suggests that the present method can capture the features of 3D embedded crack propagation and is effective.
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2012, Vol. 31 
