基于X射线衍射法的岩石残余应力测量研究

Research on Measurement of Rock Residual Stress Based on X-ray Diffraction Method

为进一步研究岩石的力学特性,提高煤炭资源开采过程的安全性,开展岩石残余应力测量试验研究。根据残余应力的形成机理,通过测量组成岩石的弹性材料——矿物晶体中残留的应力大小,得到岩石的残余应力。试验采用X射线衍射法对岩石试件进行不同入射角度的掠入射衍射测量,得到应力场作用后岩石中不同方向矿物晶体的衍射峰位变化,再由布拉格定律得到测量点的应变,根据弹性材料应力-应变关系得到测点的残余应力。结果显示:所测花岗岩的一个测点处矿物晶体的残余应力为28 MPa。

In order to study the mechanical properties of rock and improve the safety of coal resource exploitation process,the experimental study on residual stress measurement of rock was carried out.According to the formation mechanism of the residual stress,the residual stress of the rock can be obtained by measuring the residual stress in the mineral crystals which is a kind of elastic composition of rock.The X-ray diffraction method was used to get the grazing incidence diffraction measurement of the rock specimens at different incident angle,finding the changes of diffraction peak position of mineral crystals in different directions in rock after suffering stress field and then the strain of the measuring point was obtained by Bragg′s law,and the residual stress of the measuring point was obtained according to elastic stress-strain relationship.Results show that the residual stress of the mineral crystal at one measuring point of the granite is 28 MPa.