Study On Control And Mechanism Of Heaving Floor On The Thin Layer Compositional Floor

With the increasing of coal mining depth, floor stability will be the common and important subject in exploitation of deep well. This paper bases on the engineering background of the Da Ning coal mine402roadway in Ya Mei, uses theoretical analysis and numerical simulation, the field observation method, as for the thin layer compositional of floor’s heaving mechanism, influencing factors and prevention measures were studied. Through specific research work and get beneficial summaries as follows:1) This paper has regarded heaving floor of roadway as plane strain problem, and simplified the abutment pressure distribution on the floor Through the elastic mechanics calculation, got the roadway floor’s stress state at any point and the relative displacement, furthermore applied the rock mass destruction strength theory to figure out whether rock mass destruction and where will be first destroyed on the thin layer combination floor; 2) Aimed at thin layer compositional floor, using the corresponding theory and algorithm to obtain the floor’s viscoelastic displacement, the plastic displacement, rock creep displacement, flex displacement of floor surface and the hulking displacement of rock mass destruction. In final we can estimate the amount of heaving floor according to roadway staying different mining stages;3) For thin layer compositional floor, making use of soil mechanics foundation algorithm and thin elastic mechanics theory to get peak abutment pressure of the size and the peak value’s distance from wall surface and the thickness of the hierarchical distance to have an important effect on the heaving floor.4) Having done comparison analysis about heaving floor conditions in different occurrence of immediate roof’s roadway, different coal sides roadway, different width roadway,different height roadway by numerical simulation, it concluded that the occurrence of immediate roof, the lithological characters of coal sides, the width and height of the thin layer compositional floor, the effect on the stability of different floor;5) In terms of the interval coal pillar of roadway, and analyzes different fracture position in the key pieces of main roof, the influence of heaving floor by coal pillar width, immediate roof and the nature of the coal pillar relative this paper point out that in the case of leaving pillar would cause partial side of the heaving floor phenomenon; 6) Applied anchor theory to support the floor, combined the composite beams theory with strengthening arch theory to put forward the floor of anchorage parameter design method, and used clamping point to explain that anchor the parameters of the reinforcing supporting floor design;7)As for thin layer combination floor,the article made a numerical simulation analysis about top, sides ordinary support and strengthen support, combined the actual supporting effect of Da ning mine coal,it conclude that strengthen top, sides support has an important role in prevent heaving floor;8) Through researching the mechanical properties of the pier, this paper analyzed what’s role will play by the pier in the prevention ofheaving floor, and put forward a set of reasonable support method;9) For the middle402roadway of heaving floor condition in the three gateways of104coal mining surface in Da ning coal mine during the time of excavating coal, the paper has analyzed roadway unilateral of heaving floor happened dynamic mechanism and the failure process of floor during the time of back production, gived strengthen supporting measures of roadway during the back production period;10) After the long-term monitoring of reinforcing supporting in402roadway, confirmed rationality of the strengthening supporting schemes, and verified the pier support play an important role in the heaving floor prevention and control.