软岩巷道交岔点钢管混凝土组合支架支护技术研究

Research of supporting technology of concrete-filled steel tubular composite support at intersection point of soft rock roadways

为解决膨胀性软岩巷道交岔点支护难题,以清水营煤矿主斜井与2;给煤机检修联络巷交岔点为工程背景,在针对性分析交岔点地质特征和变形原因的基础上,提出基于矩形钢管混凝土组合支架的返修支护设计。通过数值模拟分析支架承载力,发现组合支架直梁段抗弯承载力不足,以钢管混凝土直梁抗弯性能试验分析结构优化依据,试验表明:在直梁受拉区焊接抗弯圆钢可以有效提高钢管混凝土直梁的抗弯承载力。采用φ50 mm的抗弯圆钢对矩形组合支架进行结构优化,模拟表明优化后的组合支架整体承载力提高了36%。在工程实践中,基于矩形钢管混凝土组合支架的支护方案应用3年来无明显变形,膨胀性软岩巷道交岔点长期保持稳定,对类似条件下的交岔点支护具有重要指导意义。

In order to solve the problem of intersection support of expansive soft rock roadways,taking the intersection point of the main inclined shaft and #2 coal feeder maintenance connecting roadway of Qingshuiying coal mine as the engineering background,and based on the analysis of the geological characteristics and deformation causes of the intersection,the repairing support design based on rectangular concrete-filled steel tube composite support is proposed. Through the numerical simulation analysis of the support bearing capacity,it is found that the flexural bearing capacity of the straight beam section of the composite support is insufficient,which affects the overall support effect. The bending test of the concrete-filled steel tubular straight beam is carried out.The results show that the welding bending round steel in the tensile area of the straight beam can effectively improve the bearing capacity of the concrete-filled steel tubular straight beam. The structure of the rectangular composite support is optimized with φ50 mm bending round steel. The simulation analysis shows that the overall bearing capacity of the optimized composite support is increased by 36%. In engineering practice,the support scheme based on the rectangular concrete-filled steel tube composite support has no obvious deformation in three years of using,and the intersection point of the expansion soft rock roadway remains stable for a long time. The research has an important guiding significance for the intersection point support under similar conditions.