Analysis On Stability Of Stratified Surrounding Rock Mass With Cracks Disturbed By Excavation

In this paper,through indoor physical experiments and UDEC discrete element numerical simulation methods,the excavation disturbance stability of layered fractured rock in different working conditions was studied,and based on the results of experiments and numerical simulations,it was carried out.Theoretical discussion and analysis.The main results are the test results of the above-mentioned surrounding rock at different inter-layer fracture spacings,different confining pressures,and different bedding plane inclinations.The purpose of this study is to provide the main damage characteristics and stress propagation characteristics of layered fractured surrounding rock under different conditions,so as to prevent the possible adverse effects of stratum-bearing surrounding rock in the project.The research content is as follows:(1)Taking full account of the structural characteristics of layered fractured rock masses,a physical test model was constructed using cement mortar unit boards to simulate the layering and masonry unit boards of rock layer and cement fly ash simulation weak layer.Then,it was loaded with a tester and used the near-field photogrammetry technique to carry out test measurements.The test results were collected and the main damage characteristics of the surrounding rock in the layered fissures were analyzed and summarized.(2)Combining with indoor physical experiments,the discrete element software UDEC was used to further simulate the mechanical response of layered fractured surrounding rock under different working conditions.By comparing the deformation characteristics and stress characteristics between different parameters,the failure law and stress distribution characteristics of layered fractured surrounding rock under different working conditions are summarized.(3)Based on the stress propagation law of a single block in a layered fractured rock mass,the stress propagation law and the solution of the target block stress under multiple forces are further deduced.This paper summarizes the force characteristics of the direct top three different geometrical forms,and gives its instability discriminant method.