基于边界元方法的次级断裂信息挖掘试验研究

为研究次级断裂发育状况，探讨了一种地震解释主断层与地质力学相结合的边界元模拟方法:首先在安德森断层分类体系下，依据断层与应力组合特征，完善次级断裂构造演化事件分类；然后应用应力张量降阶、线性叠加原理，简化应力与位移平衡方程，并在此基础上使用蒙特卡洛方法反演古应力场；最后求解应力、应变与不连续位移平衡方程，获取地层现今应力分布，分析次级断裂开度、相对密度等信息。运用该方法在杨柳矿区童亭背斜区域开展试验，结果表明区域内最小水平主应力以近北西向为主，主断层之间广泛发育交叉断裂带，次级断裂发育带连通性强，为杨柳矿区隐蔽灾害评估提供了参考资料。 

Experiment of secondary fault information mining based on boundary element method

In order to study the development of secondary faults and fracture, a boundary element method (BEM) combined with seismic interpretation of main faults and geo-mechanics is discussed. Firstly, with the Anderson's theory of faulting, the classification of secondary fault tectonic evolution events is improved under the combination of fault and stress; secondly, the stress tensor order reduction and linear superposition principle are applied to simplify the stress and displacement balance equation, and the Monte Carlo method is used to inverse the paleo-stress field. After all, the equilibrium equation of stress, strain and discontinuous displacement is solved to obtain the current stress distribution of stratum and to analyze the state of secondary fault and fracture, fracture opening or fracture relative density. Based on the geological data of the experimental area, the boundary element geo-mechanical model is established to simulate the secondary faults. The distribution of the present stress field and the information of the secondary faults are extracted. The experimental results show that the minimum horizontal principal stress is mainly in the direction of NW, and the cross fault zones are widely developed between the main faults, and the fault development zones have strong connectivity, which provides the reference data for the geological engineering design and hidden disaster assessment.