深部开采梯形棚支护棚腿底部合理约束的确定

Determination of a reasonable bottom constraint of ladder shelf legs in deep mining

为了充分发挥围岩自承载力和梯形棚支架支撑作用,针对新集三矿普通梯形棚支护工程实际,分析了围岩表面容许位移量以及支架极限承载力,确定了棚腿底部合理水平支撑抗力系数和垂直支撑抗力系数及其合理约束。结果表明,煤和泥岩围岩表面容许位移可取200 mm,泥质砂岩和砂质泥岩围岩表面容许位移可取100 mm,12#矿用工字钢水平极限承载力和垂直极限承载力分别为40 kN/m和65 kN,合理水平支撑抗力系数m=2.0×105kN/m3,垂直抗力系数为K1=1.8 MPa/m,混凝土垫块合理尺寸a=600 mm,b=450 mm,h1=200 mm,t1=100 mm,t2=100 mm,应用于工程实际,取得了较好的工程实际效果。

In order to make full use of shelf and rock supports, based on the ladder shelf supports in Xinji mine, the allowed value of surface deformation to maintain surrounding rock stability and the ultimate bearing capacity of ladder shelf were analyzed, and the reasonable horizontal and vertical resistance coefficients of shelf leg bottom were determined. The results showed that the allowed values of surface deformation were 200 mm with coal and mudstone and 100 mm with shale sand stone and silt mudstone ; the reasonable horizontal and vertical resistance coefficient were 2.0 ×10^5kN/m^3 and 1.8 MPa/m ; the horizontal and vertical ultimate bearing capacity were 40 kN/m and 65 kN with 12# ladder shelf; the rational dimensions of shelf pad were a = 600 mm, b = 450 mm, h1 = 200 mm, t1 = 100 mm, t2 = 100 mm. The findings had been applied to practical projects and good perform- ance was observed.