Study On The Large Section Intersection (Crossing) Roadway Surrounding Rock Stability

Under the Coal Mine there are many intersection (crossing) roadways,the characteristics in the intersection position has:The tunnel roof and the walls of tunnel bare areas are very great,the intersection point of stress concentration are in serious condition,causative the intersection roadway surrounding rock deformation failure is very serious,supporting work is very difficult.In this pa-per combines with intersection roadway in the Tang'An Coal Mine,let the stab-ility study on surrounding rock of the large section intersection (crossing) roa-dway as a research topic,through the theory analysis and numerical simulation, to analysis and research the intersection roadway surrounding rock force recei-ved,failure characteristics and the influence of intersection roadway surround-ing rock stability in systematically,and based of the reasearch results to make a bolt support design of the intersection point between the belt main haulage roadway and 3405 coal face subleve roadway in the Tang'An Coal Mine 3# seam coal,and thorugh the numerical simulations to show the effectiveness of this cables supporting.The results of this reaearch for the future intersection roadway cables supporting has important significance and a certain rference value.The main results are generalized as follows:1. The intersection roadway stress redistribution after excavation,signific-ant vertical triangular region stress concentration area,which end position tria-gle highest stress concentration;Triangle area surrounding the destruction of an arc shaped or a similar arc shaped,from the fracture mechanics point of view of the failure mechanism of the intersection roadway roof;get therange of surrou-uding rock need to be reinforced timbering as:the triangle of intersection road-way,the roof of intersection point and the impact of all the roadway within the surrounding rock;through analyzing make the intersection roadway surface de-formation amount significantly increases range as the way of surrounding rock need to be reinforced timbering;The main factors influence the intersection roadway surrounding rock stability is: the size of earth stress magnitude,stren-gth of surrounding rock,cross angle,the size of roadway,the intersection of roadway and the support form.2.Througe the numerical simulation experiments, concrete analys-is of different influential factors to the stability influence rules of surrounding rock on the intersection (crossing) roadway,concluded that: all types of intersection roadway, cruciform intersection roadway surrounding rock stability is the most nustable,except with the surrounding rock strength increases,the stability incr-ease,other factors increases,the stability tended to decrease; in the anchored st- ructure,the cable and anchor cable supporting way is better than the supporting single cable supporting, anchor cable supporting position to the intersection of roadway roof department played the role of full suspension, triangular area of reinforcing cable can increase the overall strength of rock Triangle, Triangle area surrounding control plastic deformation, and so the two triangular areas to help improve the bearing capacity of rock, the formation of a limited bearing on the top roof, reducing the maximum triangular area surrounding the effecti-ve destruction of the depth and span of the roof.3. According to the resules of the above research, combined with the geo-mechanical conditions of Tang'An Coal Mine's 3405 mining face, presented the supporting scheme for the intersection roadway, and through the numerical simulations verify the anchor program of the anchoring effect and concluded: For the intersection roadway, the reasonable supporting scheme can effectively improve the anchoring roadway intersections in the surrounding rock stress and reduce the roadway intersection of plastic damage and large exposed roof subsidence, increasing the bearing capacity of the trigone area surrounding rock, triangle further illustrates the superiority of bolting.