Experimental Study On The Influence Of Water Accumulation In The Mined-out Space On The Stability Of Water Proof Coal And Rock Pillar In Ximing Coalmine

Part of the water-proof coal pillars left in the mine production process are soaked by the water in the abandoned goaf for a long time,and the physical and mechanical strength of the coal pillars will be"softened",which will reduce the water-proof capacity of the coal pillars and induce the loss of the coal pillars.Stable and the possibility of water inrush due to accumulation of water in the abandoned space.This paper focuses on the complex problem of preventing water-proof coal pillars from"softening"and instability.By using trial-produced high-pressure immersion test equipment,the standard coal sample specimens taken on site are subjected to immersion tests under different simulation conditions.Through the analysis of measured data,the differences are studied.The macro-physical and mechanical properties and meso-structure characteristics of coal samples under immersion conditions are analyzed,and the factors affecting the strength weakening of coal samples are analyzed to establish a numerical simulation model and empirical formula for coal pillar damage under water immersion conditions.The main research results obtained in the thesis are as follows:(1)Design and launch the indoor simulation test of the water soaking coal rock column of abandoned hollow regions:Take the main 460kg of the main mining 2#,8#coal seam in Shanxi Province,Shanxi Province.A standard coal sample test piece 183,using independent research and design of high-pressure mine water-rock(coal)coupling test,according to the site conditions,the soaking solution having different agriculture is carried out,and the mine water-rock is carried out according to different soaking duration.Simulation test of pressurized soaking simulation.(2)The study established the process and mechanism of the high-pressure-erosive mine aqueous solution"softening"the strength of coal and rock samples,and determined the function expression relationship:analysis,research,research,research,research,and fitting,2#,8#Coal-like compressive strength,tensile strength,and cohesive force with the flexion time of the soaking time"Softnate"function of"softening factor"under different test conditions;"Softization coefficient"of each physical mechanics parameter under different test conditions;through the soaking coal rock sample Analysis of the hydraulic characteristics of mineral components and soaking solution reveals the process and mechanism of"softening"coal rock in the aqueous solution of high pressure-aggressive mine.(3)The numerical model and empirical formula of high pressure-aggressive mine water on the stability of coal rock column(Correction):On the basis of the above research results,it is constructed in the case of neighboring mineral water cases.Numerical model of high pressure-erosion mine gas water on the stability of border coal rock column,confirmed the effect of high pressure-aggressive mine water on the coal rock column,"Softization"affected by simulation calculation;finally,from part The safety angle is deployed,considering the"softening"effect produced by the anti-barrier coal proximal water soaking in the high pressure-aggressive mine water soaking,and the formula for reserving the original anti-liquid coal column is:(?).The research results of this paper not only provide a theoretical basis for the retention of water-proof coal pillars in Ximing mining area and the evaluation of the stability of coal pillars after flooding,but also provide a reference for the retention of water-proof coal pillars under similar geological conditions.value.