冲击地压巷道U型钢支护受力特征及变形破坏研究

发布时间：2018-04-16 22:11

本文选题：冲击地压 + U型钢支护　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：冲击地压是煤矿开采中遇到的重大灾害之一,研究发现,大多数冲击地压发生在巷道中。U型钢支架被广泛应用于各大煤矿巷道支护中,U型钢支护问题一直是专家学者们研究的热点和难点。然而,针对冲击地压巷道中U型钢支护的受力特征和变形破坏研究较少。本文拟用理论分析、实验室实验与数值模拟相结合的方法,通过理论分析对U型钢支架进行力学计算；通过实验室试验和数值模拟对支架承载力特性和支架变形破坏情况进行研究。首先本文归纳了冲击地压巷道U型钢支护变形破坏类型,分为支架搭接段变形破坏、支架非搭接段变形破坏和综合性破坏；简要分析了支架变形破坏原因,关键在支架与围岩作用关系和支架搭接段卡缆。简化了冲击地压巷道圆形U型钢支架力学计算模型,推导出U型钢支架滑动判别式,从卡缆预紧、搭接段滑动后和外载荷下三方面计算了U型钢支架内力,三者叠加得出了U型钢支架总内力。通过实验室试验和数值模拟,研究了U型钢支架的受力特征和变形破坏情况。支架搭接段研究结果表明：U型钢在滑动过程中,支架搭接段轴向承载力不平稳,发生间歇性骤降；卡缆螺杆与U型钢之间会发生突然错动,搭接段的收缩性能不稳定,螺母扭力越大,发生错动越频繁；模拟发现,U型钢在滑动过程中,卡缆螺杆发生偏斜,形成附加弯矩,造成螺杆局部应力集中,超过极限强度发生断裂,导致搭接段卡缆失效。U型钢支架研究结果表明：U型钢支架模型在冲击载荷作用下,支架搭接段滑移现象严重,支架模型收缩较大,在搭接段附近出现断裂破坏；模拟发现,U型钢支架在局部受载时,U型钢翼板易向两侧张开,发生屈服破坏,卡缆螺栓受拉变形出现薄弱点；U型钢翼板加固后,U型钢支架由半圆形向矩形发展,支架顶部U型钢由拱形变形发展到一字型
[Abstract]:Rock burst is one of the major disasters in coal mining.Most of the impact ground pressure occurred in the roadway. U-shaped steel support is widely used in every coal mine roadway support. It has been a hot and difficult point for experts and scholars to study.However, there are few researches on the mechanical characteristics and deformation and failure of U-shaped steel support in impact ground pressure roadway.In this paper, the method of theoretical analysis, laboratory experiment and numerical simulation is used to calculate the mechanics of U-shaped steel support.The bearing capacity and deformation failure of the support were studied by laboratory test and numerical simulation.In this paper, the types of deformation and failure of U-shaped steel support in impact ground pressure roadway are summarized, which are divided into three types: the deformation failure of support lap section, the deformation failure of support non-lap section and comprehensive failure, and the analysis of the causes of deformation and failure of support.The key lies in the relationship between the support and surrounding rock and the cable clamp in the lap section of the support.The mechanical calculation model of circular U-shaped steel support in impact ground pressure roadway is simplified, and the sliding discriminant of U-shaped steel support is derived. The internal forces of U-shaped steel support are calculated from three aspects: pre-tightening of cable, sliding of lap section and external load.The total internal force of U-shaped steel support is obtained by the three superposition.The mechanical characteristics and deformation and failure of U-shaped steel support were studied by laboratory test and numerical simulation.The results show that the axial bearing capacity of the support lap section is not stable, and the intermittent sudden drop occurs during the sliding process, and the slip between cable screw and U-section steel will occur suddenly, and the contraction performance of the lap section will be unstable.The greater the torque of the nut, the more frequent the dislocation occurs, and the simulation shows that during the sliding process of the U-shaped steel, the cable screw deflects and forms additional bending moment, which results in the local stress concentration of the screw, and the fracture of the screw in excess of the ultimate strength.The results show that under the impact load, the slip phenomenon of the overlay segment of the frame is serious, the shrinkage of the support model is larger, and the fracture failure occurs near the lap section.It is found by simulation that the U-shaped steel flange is easily opened to both sides under local load, resulting in yield failure, and the tension deformation of cable bolt is weak, and the U-shaped steel support develops from semicircle to rectangular after strengthening with U-shaped steel flange.The U-shaped steel at the top of the support develops from arched deformation to one glyph
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD324

【参考文献】