Back Analysis Of Viscoelastic Rock Mass Displacement Based On Maxwell Model

The engineering practice shows that the deformation of surrounding rock of soft rock often increases slowly with time,so the viscoelastic theory with rheological properties is not only of practical significance,but also has a wide application prospect.The key problem of viscoelastic displacement back analysis in geotechnical engineering is how to determine its calculation parameters.Therefore,this paper studies the uniqueness of back analysis of viscoelastic rock mass displacement and the optimal arrangement of measuring points,providing theoretical guidance for parameter acquisition and monitoring design in viscoelastic rock mass engineering.According to the parameter identification conditions,the uniqueness of displacement back analysis of circular roadway in viscoelastic rock mass based on Maxwell model is studied,and the influence of measuring point arrangement on the uniqueness of displacement back analysis is analyzed.The results show that only when two parameters are given,it is possible to carry out unique back analysis on other parameters.The fewer parameters to be back-analyzed,the easier the parameters are to be identified.According to the principle of maximum displacement,the displacement of measuring points in viscoelastic rock mass varies with radius and Angle,and the layout basis of measuring points in circular roadway is obtained.The study shows that the most suitable area for measuring points is the area with large principal stress direction close to the tunnel wall.According to the above research,the application examples of viscoelastic rock mass are studied.The results show that the parameters obtained by the back analysis are more accurate,which proves that the conclusions about the uniqueness of the back analysis and the optimal arrangement of measuring points are correct.