【摘要】 通过断裂力学方法研究西华山内接触带矿脉群构造的成因。根据详细实测资料发现矿脉群具有较高的断裂密度和断裂应变，对比矿脉群扩展的临界条件，说明矿脉群发展过程中驱动应力为上升的趋势，其原因是岩体界面的止裂作用使矿脉扩展阻力增大，导致矿脉扩展力相应增高，以维持矿脉扩展，形成了产生西华山大型脉状矿床的力学条件，不同于均匀体中形成的细脉带类型。更多还原

【Abstract】 The xihuashan tungsten mine is a large-scale veinlike deposit occurring in the inner contact zone of a granitic body. The mechanical conditions controlling the distribution pattern and the extent of lodeswarm are thoroughly studied. According to the factors affecting the lode-swarmpropagation from analysis of crack extension force, the fracture strain s. reflected the lode-swarm development, which is determined by the values of fracture density ρ and driving stress σ of the lode-swarm. By a number of measured and statistical data, it is demonstrated that the averagevalues of ρ and εc of lode-swarm at Xihuashan are very high, and then from the calculated elastic modulus of the granitic body, it is foundthat calculated values of its driving stress are also quite high. Thus it can be explained that the great increase in the degree of propagstion and the range of opening of the fracture in lode-swarm at Xihuashan mine results from sustained increase in the pressure of filling by ore-bearing solution.After estimated and calculated initial condition of propagation of lode-swarm is correlated with final strain and stress, it is found that the total strain increases in large amounts, and driving stress tends to increase during fracture propagation. This is probably the reason for increase in size of the lode-swarm. From comparision, both ratios ε0/ε0, and σ/σ0 of lode-swarm at Ward Lake district of America are smaller than l, indicating a process of static-propagation of the fractures which occur in an infinite matrix, but at Xihuashan mine, the increase in driving stress similarly with staticpropagation as main process is corresponding to the marginal condition of crack-arrest by the lithological boundary. Owing to the lithological features of Xihuashan granitic body manifesting that its elastic modulus is obviously lower than that of its wallrock, the crack extension force of lodes in the granitic body decreases when approaching the boundary surface and nearly equals to the decreasing range of crack extension force created by the stress-interference between the parallel lodes. The corresponding increase in driving stress of lodes, therefore, is allowed to obtain a new balance with extension force. It is concluded that lithological boundary is the predominant marginal-condition of generating large-scale lode-swarm in inner contactzone of granitic body.更多还原