原孔位多次应力解除地应力测试方法与实践

The in-situ stress measurement and practice of repeatedly stress relief on the original borehole

针对影响深部煤矿巷道围岩稳定的地应力因素,基于深埋巷道围岩体应力分布的力学特征和地应力钻孔解除法原理,探讨了在同一钻孔内间隔一定距离进行反复多次解除的地应力测试方法,建立了判别原始应力的科学依据,根据基准孔和校验孔的测量结果,可以推算出其他测点原岩应力区与巷道半径之间的关系。工程实践表明:在千米埋深的大屯矿区孔庄煤矿井底车场区域,基准孔在3.7R处进入了原岩应力区,实测垂直原岩应力值为23.3 MPa,并在校验孔和推广孔得到了验证。

With the stress-factors affecting the stability of tunnel-surrounding rock, based on the stress distribution of deep tunnel-surrounding rock and the principle of stress relief method, the in-situ stress measurement of repeatedly stress relief on the original boreholes was approached, and the scientific basis of discriminating the original boreholes was established. According to the measurement of basic borehole and checking borehole, the relations between the original rock stress in other measuring area and radius of the tunnel could be deduced. The project practice showed that, in Kongzhuang colliery, Datun coal mining area with buried depth more than 1 000 m, the basic borehole enter the original rock stress area at the distance about 3.7R, the original vertical stress result is 23.3 MPa, which was proved in the checking borehole and extension borehole.