流变岩体中三向压力传感器的应力恢复规律模拟研究

流变应力恢复法是一种专门针对深部软弱围岩提出的地应力测量新方法;该方法在围岩钻孔中埋置三向压应力传感器,并注浆充填密实,进而根据传感器的实测恢复应力来分析围岩的初始应力状态和巷道围岩应力分布及演化。压力传感器实测应力的恢复规律是流变应力恢复法需要解决的关键问题之一。采用数值方法模拟流变应力恢复法的测试过程,研究不同围岩黏弹性模型、不同围岩参数、不同地应力状态以及不同注浆材料模量参数对三向压应力传感器实测应力的影响规律;同时,基于大量文献中的流变试验数据,得到了不同围岩等级下传感器实测应力的恢复规律。该研究为流变应力恢复法的成功实施提供了理论依据。

Simulation of stress recovery rule of three-dimensional pressure transducer embedded in rheological rock

Rheological stress recovery (RSR) method provides a new approach for in situ stress measurement in deep soft rock. It is supposed that rock stresses will recover gradually to be stable with time and can be measured by embedding 3D pressure transducer into the borehole. Then the in situ stress or the evolution of the surrounding rock stress can be determined by the recovery stress measured by the transducer. Therefore, the recovery rule of the stress measured by the transducer is the key of the RSR method to determine in situ stresses. In this paper numerical software is proposed to simulate the testing process of RSR method. The effects of different viscoelastic surrounding rock, creep parameters, stress state and grout material on the recovery stress measured by the transducer are discussed according to the established calculation model. Based on the rheological experimental results of rock in the literature at home and abroad, the recovery rule of the stress measured by the transducer under different rock grades is obtained, which provides theory proof for the application of RSR method.