一种常用让压锚杆的数值模拟技术研究

Research on numerical simulation technology of a commonly used yielding bolt

让压锚杆可有效解决深部巷道锚杆破断问题,让压管锚杆是其中一种常用类型,但目前在工程应用层面缺少有效的数值模拟技术。通过分析典型静力拉伸试验曲线特征,建立了让压管锚杆的拉伸力学模型;采用FISH语言对FLAC3D内置Cable单元进行二次开发,建立了让压管锚杆数值模型,形成了完整的数值模拟技术。拉伸试验数值模拟表明:当锚杆轴力达到168 kN时进入让压阶段,伸长量从10.51 mm增长至29.48 mm的同时轴力保持168 kN不变,与室内试验结果吻合较好。深埋巷道数值模拟表明:让压管锚杆破断数量比常规锚杆减少了80%,且顶板沉降和边墙内移分别减少了50.6 mm和26.5 mm。

Yielding bolt can effectively solve the problem of deep roadway bolt breakage,Y-bolt is one of the common types,but at present,there is a lack of effective numerical simulation technology in engineering application.By analyzing the characteristics of typical static tensile test curve,the tensile mechanical model of Y-bolt is established.The secondary development of built-in cable element in FLAC3D is carried out by using FISH,and the numerical model of Y-bolt is established,forming a complete numerical simulation technology.The numerical simulation of tensile test shows that when the axial force of the bolt reaches 168 kN,it enters the yielding stage,the elongation increases from 10.51 mm to 29.48 mm,and the axial force remains 168 kN,which is in good agreement with the indoor test results.The numerical simulation of deep buried roadway shows that the broken number of Y-bolt is 80%less than that of normal bolt,and the roof settlement and side wall internal displacement are reduced by 50.6 mm and 26.5 mm respectively.