锚杆(索)支护体让压减震技术研究

Research on Yield-damping Technology of Bolt (Cable) Support Body

在大埋深、高地应力等复杂地质条件下,现有的支护体无法有效适应围岩的大变形,易导致锚杆、锚索支护体大面积破断失效。详细分析了锚杆(索)支护体的让压减震作用机理,提出了锚杆(索)支护体让压减震功能实现的关键技术(让压点、让压距离及减震能力),并对工程中常用的单炮管和新型让压减震装置特性进行了对比分析。研究表明:①新型让压减震装置在高度相同的情况下,壁厚3.0 mm、3.5 mm时所对应的让压点分别为60kN、73 kN,约束环壁厚越大,让压点也越大;②在约束环壁厚相同的情况下,35 mm高度下让压距离约15 mm,40mm高度下让压距离约20 mm,随着约束环高度的增大,让压距离也随之增大;③在受到外部冲击荷载作用时,其弹性压缩量可达4~5 mm,具有明显的吸收震动荷载的能力,让压减震效果显著,单炮管让压装置的让压距离仅为新型让压减震装置让压距离的1/2,受到外部冲击荷载作用时,在不同冲击高度下的冲击变形量仅有0.5 mm左右,压缩之后的弹性恢复能力方面存在明显不足,减震效果不明显。

For the complex geological conditions such as large buried depth and high ground stress,the existing supporting body can not adapt to the large deformation of the surrounding rock,resulting in the failure of the bolt and cable support to break.Based on the detailed analysis of the mechanism of the yield-damping mechanism of the bolt(cable)support body,the key technology for the yield-damping function of the bolt(cable)support body(yield point and yield distance and shock absorption capacity)is proposed,and the characteristics of single gun barrel and new pressure relief device commonly used in engineering are compared and analyzed.The study results show that:①under the same height of new pressure relief device,the pressure points corresponding to the wall thickness of 3.0 mm and 3.5 mm are 60 kN and 73 kN respectively,and the pressure of the confinement ring is larger,so the larger the wall thickness of the confinement ring,the larger the pressure point;②under the same thickness of the confinement ring,the pressure distance is about 15 mm at a height of 35 mm,and the pressure is about 20 mm at a height of 40 mm,with the increase of the height of the confinement ring,the pressure distance is also increased correspondingly;③when it is subjected to external impact load,its elastic compression capacity can reach 4~5 mm,the ability to absorb shock loads is obvious and the pressure damping effect is remarkable,the compression distance of the single gun barrel is only the 1/2 of the one of new pressure relief device,and the impact deformation at different impact heights is only about 0.5 mm when subjected to external impact loads.There is a significant lack of elastic recovery ability after compression,and the damping effect is not obvious.