Numerical simulation of creep characteristics of soft roadway with bolt-grouting support

Abstract

Based on the engineering background of a soft rock roadway in Qinan Coal Mine 82 Area, Huaibei Mining Group, three creep models with different support patterns in soft rock roadway were established by using geotechnical software of FLAC2D. According to the calculation results of different models, the change law of mechanical properties with the time of bolt-grouting support structure was obtained. Furthermore, for the test bolt-grouting support roadway, the deformation law of surrounding rock got by underground industrial experiment and field observation accords with the creep law got by numerical calculation. The results of numerical calculation and field observation show that, compared with other supports, the creep of bolt-grouting support roadway enters the steady-state creep stage from tertiary creep stage ahead, the deformations of roof, floor and two sides are decreased greatly, the plastically deforming area in surrounding rock is reduced obviously, and the distribution ranges of maximum and minimum principal stress are shrank obviously. All those fully show that the bolt-grouting support has its remarkable advantages in controlling surrounding rock creep and improving the whole strength of surrounding rock and self-bearing capacity.