Roadway Floor Heave Control Under The Influence Of Tectonic Stress And Mining Stress

Aimed at the characteristics of serious floor heave of soft rock roadway under the joint action of mining stress and tectonic stress, based on the engineering conditions of floor support of-250 tied for return air bord-up roadway in Hebi Coal Mine 10, this article analyzed the reason of floor heave of soft rock roadway in combined ways of on-site inspection, theoretical analysis, numerical simulation, similar simulation,underground test. The research results suggest that: weaker rock stratum of roadway floor, higher horizontal mining stress and tectonic stress are main reasons of roadway floor heave. Through the establishment of mechanical models of flat structure roadway floor and anti-arch structure roadway floor, this article studied the effect of different floor structure on the floor heave, concluded that roadway floor anti-arch structure can make full use of floor surrounding rock’s resistance to pressure, give full scope to self-supporting capacity, avoid surrounding rock’s tensile fracture. By using numerical simulation, this article analyzed the effect of different floor structures and support patterns on the roadway floor heave control. After contrast and analysis, it was found that "anti-arch structure+grouting+brickwork" support method and whole section of metal bracket enclosed support method are effective floor support program. The supporting effect of " anti-arch+grouting+brickwork " support method and " floor grouting+whole section of metal bracket " enclosed support method was analyzed contrastively by using similar simulation test, and this article drew a conclusion that:the joint of U-steel and anti-arch brickwork with siding-walls support is the supporting weakness; the supporting strength of metal bracket can be raised by introducing "floor grouting+whole section of metal bracket" enclosed support method. Through the field test, it was found that " floor grouting+whole section of metal bracket " support method can control roadway floor heave efficiently, but also it has the advantages of simple construction, high speed of construction, good economic benefits. This support method provides a reference for floor heave control of soft rock roadway that bothered by horizontal mining stress and tectonic stress seriously.