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| 全长锚固锚杆支护破断行为数值计算研究 |
| Numerical study on the rupture behaviour of fully grouted rock bolts |
| 投稿时间：2020-12-20 修订日期：2021-05-22 |
| DOI： |
| 中文关键词: 锚杆支护 拉拔模拟 破断行为 拉伸破断应变 |
| 英文关键词: rock bolting pull-out simulation rupture behaviour tensile failure strain |
| 基金项目:国家自然科学基金（51904302和52034009），中央高校基本科研业务费（2021YQNY05） |
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| 中文摘要: |
| 数值计算广泛应用于锚杆支护力学性能研究中，其中三维有限差分软件FLAC3D含有能够模拟支护的结构单元，常用于巷道支护的模拟研究中。但该软件中锚结构单元没有考虑杆体破断行为，模拟效果与实际情况有较大出入。因此本文采用桩结构单元模拟锚杆，首先对比锚结构单元和桩结构单元力学特点，发现桩结构单元能够模拟杆体破断行为，且模拟结果与物理试验结果一致。随后研究拉伸破断应变对锚杆支护性能的影响，发现无围压和有围压条件下拉伸破断应变增加，导致锚杆破断时对应拉拔位移增加，并通过线性拟合得到两者间关系式。此外，杆体破断前锚杆轴力从拉拔端向自由端逐渐递减。杆体破断后锚杆轴力迅速下降至零附近。 |
| 英文摘要: |
| Numerical calculation is widely used in studying the mechanical performance of rock bolting. Among them, the three-dimensional finite difference software FLAC3D has the structure elements that can simulate the rock reinforcement. Therefore, it is widely used in numerical investigation of the roadway support. However, in this program, the cable element neglected the rupture behaviour of bolts. This leaded to the significant difference between simulation and physical test results. Therefore, this paper used the pile elements to simulate rock bolts. First, the mechanical performance between cable and pile elements was compared. It was found that the pile elements can simulate the bolt rupture behaviour. Moreover, there was a close match between simulation and physical test results. Then, the influence of the tensile failure strain on the bolting performance was studied. It showed that no matter whether the confinement was applied, the pullout displacement where rupture occurred, increased with the tensile failure strain. Linear regression was conducted to acquire the relationship between them. Additionally, before rupture, the axial load in the bolt decreased gradually from the loaded end to free end. However, after rupture, the axial load in the bolt decreased rapidly to around zero. |
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