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.