锚杆支护应力场测试与分析

在实验室建立了锚杆支护应力场测试模型,测试了单根与2根锚杆在不同拉伸载荷下的支护应力值及应力场分布特征,分析了2根锚杆形成的支护应力场相互叠加与影响的特点。采用数值模拟,计算了单根、2根锚杆在不同载荷下形成的支护应力场及影响因素,并将实验室测试结果与数值模拟结果进行了对比。研究结果表明:单根锚杆在端部附近应力较高,随着远离锚杆端部,应力逐渐减少,锚杆中部应力较小;在远离锚杆的一侧出现拉应力区;2根锚杆形成的支护应力场主要在模型中部叠加,由于模型前后表面应力扩散范围小,导致两表面附近中部应力很低,模型中心部位远离锚杆,应力也比较小。最后,提出了存在的问题及改进建议。

Test and analysis on stress fields caused by rock bolting

The test model was established to measure rock bolting stress fields in laboratory，the distribution features of the stress fields caused by single and two bolts with various tensile loads were tested，and the stress field overlapping and interaction caused by two bolts were analyzed.The stress fields caused by single and two bolts were also computed by numerical simulation，which were compared with those obtained from laboratory tests.The research results points out the stress around single bolt ends is pretty high，and the stress is decreasing away from the ends with pretty low value in middle of the bolt.The tensile stress zone appears around right side of the model distant to the bolt.The stress overlapping caused by two bolts mainly appears in the middle part of model.However，the stress in the middle parts around the front and rear surfaces of the model is very low，where the stress diffusion scopes are limited，and the stress in the center of the model is also low as it is distant to bolt ends.Finally，the suggestions for improving bolting stress test model and methods were put forward.