关于钻孔应力计初始应力值与围岩应力变化的试验研究

Experimental Study on the Initial Stress Value of Borehole Stress Meter and Change of Surrounding Rock Stress

本文针对在实际生产及测量过程中存在的问题,为提高钻孔应力计监测精度,对钻孔应力计初始应力值设定与围岩应力变化关系进行试验研究。采用液压钻孔应力计模拟不同初始应力值的情况下的相对应力值,并对数据进行分析,得出当初始应力值设置越大,对应围岩应力数值越大,“围岩应力”与钻孔应力两者压力差值虽然成正态递增,但两者压力差值与线性比值都逐渐增大,系数范围参考值在1.15~1.4之间,初期系数较小,后期系数变大。通过采取试验研究,能够有效的提高围岩相对应力的监测精度。

Aiming at the problems existing in the actual production and measurement process,in order to improve the monitoring accuracy of the borehole stress meter,the relationship between the initial stress value setting of the borehole stress meter and the stress change of surrounding rock was studied.The hydraulic borehole stress meter is used to simulate the relative stress value under the condition of different initial stress value,and the data were analyzed.It is concluded that the greater the initial stress value,the greater the corresponding stress value to the surrounding rock.Although the pressure difference between surrounding rock stress and borehole stress is normally increasing,the pressure difference and the linear ratio increase gradually.Coefficient of reference ranges between 1.15 and 1.4.The early coefficient is small.The late coefficient is bigger.By means of experimental study,the monitoring accuracy of relative stress of surrounding rock can be effectively improved.