The Impact Of Mountainous Terrain On Buildings And Protective Coal Pillar Design In Mining Area

The large-scale mining of coal resources promoted the development ofnational economy and the improvement of people’s life. But the subsequentsurface movement and deformation caused serious damage to the buildings andthe mining area ecological environment, which affect people’s normal life there.Thus the problem of mining subsidence has always been concerned widely bythe researchers.At present, the study of mining subsidence in plain has been relativelymature at home and abroad. However, there is about more than one-third of thecoal mine located in the mountains in our country. Mountain surface movementand deformation is unavoidably influenced by the terrain factors, which make itscharacteristics has the obvious difference with the plains. The error will appear ifwe fully apply the existing subsidence theory of plain to the mountainous area,which is likely to make the construction plans and the design of protective coalpillars underground are unreasonable. This will cause the destruction ofbuildings to different extent. Therefor the study of law about surface movement and deformation and protection coal pillar design is of great significance for theground buildings in mountains.In this paper, the impact of terrain of buildings in mountains is analyzedfrom theory and actual measurement. The paper set up different mining slopeand location models with Midas GTS numerical simulation software based onthe geological conditions of one Coal Mine in Shanxi. Surface deformationcharacteristic with different slope were analyzed systematically. According tothe deformation results, a simple linear regression equation is developedbetween displacement angle and slope, which provide more reference for futureprotection design of buildings in mining areas. At the same time, it is analyzedthat the effect of terrain on buildings through horizontal movement andcurvature. In addition, the feasibility and rationality of the formula calculatingthe displacement angle was proved by protective coal pillar design example inSunjiagou Coal Mine. The main research results are as follows:1. When the buildings are located in valley or the gradient change points,deformation caused by mining slip is relatively serious. Buildings aresusceptible to damage. When the buildings are located in the top of the mountain,deformation caused by mining slip is small. Buildings are relatively safe.2. The surface movement and deformation is related to surface slope. Thegreater the gradient is, the greater the influence of slope slip on the surfacemovement deformation，the more obviously the change trend.3. The surface movement and deformation distribution curves were no longer have symmetry in mountain. The terrain has minimal impact onsubsidence distribution curve among the five kinds of deformation curves. Thedeformation in horizontal direction is sensitive to the change of slope than in thevertical direction.4. The surface movement and deformation is affected by relative positionbetween the gob and slope. When the terrain is kept constant, the influence ofslope slip on surface movement and deformation change with the differentposition between the gob and slope. When the gob is located in the foothills, theslope slip affects mainly the lower half of the hill. When the gob is located in themountainside, the slope slip affects the lower half more than the upper portion ofthe hill. When the gob is located in the hilltop, the slope slip affects mainly theupper half of the hill.5. When the directions of the slip inclination and the subsidence basin arethe same, the displacement angle decreases with the increase in slope. Themovement boundary of subsidence basin shifts outward. When the slipinclination and the subsidence basin have the opposite directions, thedisplacement angle increases with the slope increases. The movement boundaryof subsidence basin shifts inward.