应变分析与裂缝预测技术在地学领域具有重要应用意义.离散元方法虽然能有效分析含有大量间断的问题,但目前在地学领域应用较少.文中尝试使用离散元方法表示符合实际性质的岩石,模拟水平挤压环境下滑脱构造的形成过程,并对变形过程中的应变分布变化与裂缝生成规律进行了分析.结果表明:在挤压环境的滑脱构造中,裂缝产生的高峰期先于断层明显活动期,局部区域内聚集的大量裂缝是产生断层的诱因;已经出现明显活动的断层中产生的裂缝较少.裂缝集中区域和应变集中区域相互重叠,裂缝越发育则应变越强烈.受同一个断层影响的裂缝首先在断面上集中出现,随后产生在断面周边区域;在受断层影响的范围内,裂缝距离断面越远则形成时间越晚.该成果还表明离散元方法在应变分析与裂缝预测研究中具有巨大潜力.%The application of strain analysis and fracture prediction technology is of great importance in geosciences. However, the discrete element method (DEM), which is suitable for solving problems with discontinuous property, has not been widely used in this field. This paper presents an attempt to construct DEM model of a bulk of rock with realistic properties, followed by a simulation of the evolution of a compressional detachment structure. The strain distribution and fracture formation are analyzed afterwards. As to the detachment structure, the result shows that the interval in which the fracture generation reaches its peak precedes the one in which the fault appears the most active. Additionally, fractures and strain distribution share the same concentrating areas, and the number of fractures is proportional to the intensity of the strain. Also, fractures that are related to the same fault first concentrate on its fault plane, then appear in the vicinity of that plane. It indicates that, within the range of fault influence, the further a fracture is from the fault plane, the later it is generated. Above all, the result has revealed a great application potential of DEM in the field of strain analysis and fracture prediction.
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