Evolution Research On Steeply Bottom Damage Of Fully Mechanized Working Face

Steeply inclined thick coal seam fully mechanized working face during mining, regardless of mining equipment, process and control of surrounding rock are constrained by technology and equipment factors. Because of the steep coal face with asymmetric mechanical characteristics of surrounding rock, with the working face advancing, floor also appears asymmetric deformation. This leads to floor rock crack and move downward slide, work face appeared widespread instability of floor strata. In the composition of supports and surrounding rock support system, the floor also play a key role. Steeply inclined working face advance process, the instability of floor will greatly influence support coordinate stability of surrounding rock support system, and can lead to catastrophe of surrounding rock. Face the supporting overturned irregular phenomenon.In order to obtain Stress distribution and damage law of Steeply inclined working face floor, According to the characteristics of working face of steep, Respectively on trends and tendencies in the working face floor damage mechanism analysis, concluded that Steeply inclined soleplate mechanics criterion limit analytical formulas, and the tendency to face the direction part, middle and upper three locations in the corresponding floor biggest failure depth of analytical formulas, working face in front of the coal wall caving width and maximum floor rock mass damage depth and horizontal distance of working face end. Found floor destruction be concerned with working face length, coal seam dip Angle, average unit weight and working face advance distance and other factors, the front of Coal wall abutment pressure along with the increase of advance distance and overlay, the same floor stress and the increase of advance distance was positively proportional relationship. Through theoretical analysis and numerical simulation can be concluded that the front of Coal wall abutment pressure along with the increase of advance distance and overlay, the same floor stress and the increase of advance distance was positively proportional relationship. Along the working face, the lowest, in the central and upper three working position floor by vertical stress size effect, The lowest minimum, upper maximum, middle times, floor displacement of the same regular. Another working face length is different, the up and down on either side of the side abutment pressure concentrated coefficient and decreases as the dip Angle of coal seam, And the measure on reducing speed is greater than the measurement, but the side abutment pressure concentrated coefficient is always greater than the upper; On the other hand, Steeply inclined working face floor displacement is vertical displacement and horizontal displacement of the fitting, the show that floor and floor heave, plastic deformation and destruction in serious area of floor heave of bottom slip, should increase the floor rock mass strength and increase the cohesion of rock mass to prevent the destruction of the bottom slip to support, coal winning machine equipment damage. By lowering the floor stress concentration, the change of pressure relief and the degree of stress and strain energy in the process of change to control the steep coal seam working face floor of floor rock mass damage due to unloading. Choose floor grouting as a temporary support control steep seam floor effect of construction process of sliding failure, can be used widely in the similar condition working face. Research results can provide theoretical basis for steeply inclined working face floor management.