The study of stability mechanism of soil nail support in the fault of broken surrounding rock

In parallel to the fault of gateways of breakage and the tectonic stress action, it presents the characteristics of the asymmetric deformation damage and roadway maintenance difficulty,stress state of roadway surrounding rock near fault which has deformation damage with asymmetry, So that strengthening the soil nail supporting is conducive to the stability of surrounding rock near fault coal.

Fault near the roadway surrounding rock is broken, but it is not obvious for the weak structural plane, which can be regard as a continuum;The stability mechanism of soil nail near the fault crushed surrounding rock of coal roadway were studied.The following four points:

1)The soil nail supporting near the fault crushed surrounding rock of coal roadway delayed balance time about stress after excavation, reduce the instable possibility of broken surrounding rock in a short period of time.

2)Soil nail support improved the stress state of surrounding rock at two sides of roof and floor shallow , which increases the residual strength of surrounding rock, contributed to the stability of surrounding rock. At the same time, bearing capacity of roof bolt out of the shearing have an effect on reducing the possibility of unstability of roof caving.

3) Near the fault stress state and deformation of roadway surrounding rock damage with asymmetry, it has serious damage to the side and deformation of surrounding rock near fault deterioration of surrounding rock stress state, it is conducive to the stability of surrounding rock by strengthening soil nail reinforcement near fault coal.

4) Engineering practice indicates that it is has significant effect on the stability of surrounding rock with high strength, high pre-tightening force, extended beam web and soil nail combined support near fault crushed surrounding rock of coal roadway.