Study on the Law of Influence of Supporting Time on Relaxation Deformation of Surrounding Rock

Taking the underground powerhouse of Panlong pumped storage power station as the engineering background, this paper established a three-dimensional numerical calculation model for the main powerhouse according to the excavation plan of the powerhouse. 3DEC software was used to simulate the excavation process of the powerhouse through layered and step-by-step excavation method, and compared and analyzed the deformation of surrounding rock, the development depth of plastic zone and the dislocation of soft rock strata under three different supporting opportunities. The influence of support on relaxation characteristics of surrounding rock is studied. Through three different support timing schemes, the effect of different support timing on the relaxation deformation of the surrounding rock of the main workshop is studied by using the stratified step excavation simulation method.