Study On Intersection Stability In Great Depth Of Cover In Tang Kou Colliery

Roadway crossing point is the intersection of roadway or bifurcation of roadway. Due to the impact of two or more intersecting roadway, the surrounding rock force is very complexity. With the increasing of mining depth, all kinds of engineering stability problem would come forth.. So,study on stability of roadway intersection in great depth of cover is imperative question. A comprehensive investigation on the stability of coal mine roadway intersection has been conducted around 1000m below the surface based on the laboratory testing ,field monitoring and numerical simulation. In the laboratory tests, the fine sandstone samples had been collected from the field and tested to obtain the basic mechanical parameters, such as UCS, Triaxial compressive strength with various levels of confining pressures, as well as the modular of elasticity, etc. During the field monitoring, the wire extensometers were installed on the both roof and rib of the roadway intersection to determine: 1) effect of time on stability of roadway intersection, and 2) the key factor(s), which may strongly influence the stability of roadway intersection. Combining the mechanical properties of surrounding rock mass and the deformation behavior of roadway intersection, as well as the great depth of cover, mechanisms of the roadway intersection are analyzed and proposed. The underground monitoring results clearly demonstrated that the large span of opening, and great depth of cover are major factors, which influence the stability of the roadway intersection, even the surrounding rock mass is comparatively strong. In geological factors,it has been studied on effect of three factors,that is,crossing point depth, rock strength, as well as lateral pressure coefficient;In structure of intersection,it has been studied the "十", "T", "Y","X" and "L" five cross-type forms;In construction methods,it has been studied on different excavation of the "ten" form intersection;Through the simulation of factors,the features of factors has been found, which would give a prediction for design,construction and support of great depth cover. At the same time, the impaction of geological structure on roadway intersection has been pointed out, in order to provide a reference for optimizing the layout of intersection.