基于FLAC^3D数值模拟的清徐地裂缝与交城断裂成因关系研究

Study on Genetic Relationship between Qingxu Ground Fissure and Jiaocheng Fault by FLAC^3D Numerical Simulation

基于断裂力学理论,应用FLAC^3D数值模拟方法对交城断裂活动时附近土体的变形特征进行模拟计算。计算结果表明:断层活动带动上覆土层差异沉降及应力场变化,当断层错动量达到一定程度,断层附近出现拉应力区,土体在拉张应力和自身重力作用下产生垂直差异形变,从而产生地裂缝。将数值模拟结果与方山探槽揭示的地裂缝剖面特征进行对比,二者结果相互印证,说明清徐地裂缝是交城断裂活动的结果,二者具有明显的对应关系,地裂缝为构造成因裂缝。数值模拟结果为研究断裂和地裂缝成因关系提供了佐证。

Based on fracture mechanics theory,this paper used the FLAC3D numerical simulation method to simulate the deformation characteristics of soils near Jiaocheng fault.The results show that the fault activity caused the differential settlement and the stress field change of the overlying soil.When the fault rupture reaches a certain level,a tensile stress zone appears near the fault.Under the action of tensile stress and gravity,the soils undergo vertical differential deformation,which causes ground fissures.Comparing the numerical simulation results with the profile characteristics of ground fissures revealed by the trench,the two results confirm each other.It further shows that the Qingxu ground fissures are the result of the Jiaocheng fault activity,and there are obvious corresponding relationships.The ground fissures are structural origin fissures.The numerical simulation results provide another evidence for the study of the genetic relationship between faults and ground fissures.