|
Abstract Coal-rock mass have extremely complex discontinuous deformation and heterogeneous characteristics. The traditional numerical methods represented by Finite Element Method (FEM) are difficult to accurately describe the whole process of damage accumulation and progressive failure. Based on the no-nlocal Peridynamics (PD) method, the corresponding micro-modulus function and critical elongation are derived by reconstructing kernel function of the constitutive force function. The heterogeneity characterized by random pre-breaking bond is introduced into the homogeneous discrete model, so that the Peridynamics can be applied to the simulation and analysis of deformation and failure of natural heterogeneous materials and structures. Taking Fucun Coal Mine as an example, heterogeneous Peridynamic simulation model is established. The deformation and failure laws of roadway surrounding rock and failure characteristics of coal pillars with different widths are analyzed. It is found that when the width of coal pillar is 5 m, the roadway is at the edge of the extrusion deformation zone. Due to the dramatic change of the abutment pressure, the roadway surrounding rock is seriously deformed and damaged; when the width of coal pillar increases to 6 m and 7 m, the roadway surrounding rock gradually moves away from the extrusion deformation area, the influence of the basic roof rotation movement of the goaf on coal pillar is relatively weak, and the deformation and damage of the roadway are small; when the width of coal pillar continues to increase, the roadway surrounding rock will enter the the stress increases area. Due to the large bearing pressure of the external stress field, the deformation and damage of the roadway will increase. Considering the deformation and damage characteristics of roadway surrounding rock and coal pillar, the reserved width of coal pillar is finally determined to be 7 m. The proposed Peridynamic simulation model provides a new and effective simulation tool for the optimization of coal pillar size in gob-side entry driving.
|
|
Received: 11 September 2023
Published: 04 June 2024
|
|
|
|
2024, Vol. 45 
