不同温度场下断层黏滑失稳过程模拟

Simulation of Fault Stick-Slip Instability Processes Under Different Temperature Fields

随着国家对深部工程开发的需求增大,深部高岩温条件下断层黏滑失稳过程的演化规律和形成机制亟待研究.为此,本文借助离散元数值模拟手段,构建热力耦合数值模型,对6种不同温度场条件下的断层黏滑力学行为进行了详细研究,探究了不同温度场对断层黏滑失稳过程的影响机制.结果表明:随着温度场的不断上升,断层黏滑的破坏形态以及破坏模式均发生改变;断层黏滑次数、启滑应力以及启滑应力降整体上随温度上升,呈现不断下降的变化趋势;断层黏滑能量耗散以摩擦滑动为主;断层启滑时,总应变能与温度呈正相关,耗散能与温度呈负相关.

With the development of deep engineering in China,the evolution law and formation mechanism of fault stick-slip instability process in the deep area and high rock temperature need to be studied.Therefore,a numerical thermo-mechanical coupling model is constructed with discrete element code,the mechanical behavior of fault stick-slip under six different temperature fields was studied in detail,and the influence mechanism of different temperature fields on the process of fault stick-slip instability was explored.The results show that the failure patterns and failure modes of fault stick-slip change with the increase of temperature.The number of stick slip,initiation slip stress and initiation slip stress drop show an overall decreasing trend with increasing temperature.The energy dissipation of fault stick-slip is dominated by frictional sliding.When the fault starts sliding,the total strain energy is positively correlated with temperature,and the dissipated energy is negatively correlated with temperature.