Numerical simulation study on effect of bedrock intrusion on strata behaviors of roadway

Abstract

Based on the coal mine engineering, the mechanical model with the horizontal forms of bedrock intrusion is established, and the characteristics of in-situ stress distribution in the intrusion area are analyzed. The numerical model is built based on FLAC3D, and the distribution and influence law of stress field, deformation field, plastic zone of surrounding rock of roadway and advance abutment pressure in face caused by rock intrusion are analyzed. The results show that the stress concentration coefficient of the geo-stress increases with the decrease of the elastic modulus ratio of coal and rock, and increases with the increase of the thickness of the bedrock. The stress concentration degree of the surrounding rock of the roadway invaded by the bedrock is obvious, and the coal and rock mass are easy to be destroyed by compression and shear, which is very disadvantageous to the stability of the roadway, the distribution of shear plastic zone of roadway surrounding rock invaded by sill is wider. As the face is close to the bedrock invasion area, the influence of bedrock invasion on the distribution of advance abutment pressure is gradually increased, and the characteristics of stress mutation gradually appear, which is unfavorable to the stability of surrounding rock.

Keywords

• bedrock intrusion
• mechanical model
• roadway surrounding rock
• rock pressure
• numerical simulation