Experimental Study On Deformation And Failure Characteristics Of Abnormity Roadway Within Steep Soft Coal Seam With Hard Roof

Steep hard top deformed soft coal roadway under the different mechanical properties ofsurrounding rock, which reduces the surrounding rock stress to be asymmetric loaddistribution, and the increasing of dip angle of coal seam, result in the difficulty of roadwaysupport and not meeting the needs of high production and efficiency mine safety, therefore. itwill have an important scientific significance and economic value to study the roadwaysurrounding rock deformation and failure characteristics of steep hard top deformed soft coalroadway.Under the background of Xinjiang Coking Coal Mine Group Co., Ltd.25221roadway,combined with field observations, similar material simulation, numerical simulation (FLAC2D)and theoretical analysis, this paper studies and analyzes the steeply inclined hardtop shapedsoft coal roadway deformation and failure characteristics and stability control. The researchesconclude that:(1) The deformation of the sides of steep hard top deformed soft coal roadway is largerthan that in top and bottom. The governing deformation emerged on the longer side of the two,the maximum force and longer side anchor (cable) has overall maximum load, the top bolt isfollowed, the shorter sideanchor is minimum. This shows that the longer side control should beemphasized;(2) Profiled in Steep hardtop soft coal during tunneling, high load is greater than theupper middle and lower help, coupled with the role of weathering and erosion, the upper bodyhas a loose coal trend, high-top upper easily deformed lateral tension due to release or relievethe pressure and the formation of the roof, along with the passage of time, it is easy to creep,resulting in high-top instability failure;(3)As result of steep hard top deformed soft coal roadway influenced by the coal seam’s dip angle, the deformation of surrounding rock damages is asymmetric, which presents themutual dislocation deformation characteristics of "high-top slip down low to help, swollenfrom the floor, roof fracture ";(4) Based on steeply inclined shaped roadway deformation under load and non-symmetryviolation, the proposed roadway for the abnormity of roadway with asymmetric applying theanchor wire rope coupling support, combined with the stability of roadway control principle,designing the special-shaped roadway support plan;(5) Support programs for different numerical analysis shows that roof bolting density isreduced by increasing the roof, high strength bolt, the surrounding rock stress state isimproved, shaped roadway stability control is feasible. At the same time only three rows boltsis installed in the roof, the stability of surrounding rock can be obtained, reducing the numberof anchor, meeting support requirements, improving support efficiency can be Achieved.