剪切作用下新型拉力分散型麻花锚杆承载性能研究

Study on the bearing capacity of a new type of tension dispersed fried dough twists bolt under shear

【目的】新型麻花锚杆能显著提高锚杆的抗变形能力与抗剪能力,为进一步探讨剪切作用下新型麻花锚杆的承载性能,【方法】基于室内大型锚固拉拔试验系统,开展了不同剪切角度下新型麻花锚杆和传统锚杆的加卸载拉拔试验,并定义了承载力和有效变形率两个指标对承载性能进行评价,最后运用ABAQUS数值模拟验证试验结果的准确性。【结果】结果显示:对于剪切角为90°、60°、30°,新型麻花锚杆的承载性能分别提升了9.93%、15.28%、10.23%,有效变形率分别为传统锚杆的4.02倍、3.48倍、2.18倍;剪切角由90°减小至60°,新型麻花锚杆与传统锚杆承载性能分别增加了15.21%与9.86%;剪切角由60°减小至30°,新型麻花锚杆与传统型锚杆承载性能分别增加了13.37%与18.56%。【结论】结果表明:通过对承载力和有效变形率两个参数的评判,新型麻花锚杆比传统锚杆,承载性能与抗变形能力均得到提升;相同锚固长度和剪切角下,当承载能力相同时,新型麻花锚杆的抗变形能力优于传统锚杆;当抗变形能力相同时,新型麻花锚杆的承载性能优于传统锚杆。数值模拟得到的结果的一致性验证了试验结果的有效性。

[Objective]The new twist bolt can significantly improve the deformation resistance and shear resistance of the bolt.In order to further explore the bearing capacity of the new twist bolt under shear action.[Methods]Based on the indoor large-scale anchorage pull-out test system,the loading and unloading pull-out tests of new twist bolt and traditional bolt under different shear angles were carried out,and the bearing capacity and effective deformation rate were defined to evaluate the bearing performance.Finally,ABAQUS numerical simulation was used to verify the accuracy of the test result.[Results]The result show that for the shear angles of 90°,60°and 30°,the bearing capacity of the new twist bolt is increased by 9.93%,15.28%and 10.23%respectively,and the effective deformation rate is 4.02 times,3.48 times and 2.18 times of the traditional bolt respectively.The shear angle decreases from 90°to 60°,and the bearing capacity of the new twist bolt and the traditional bolt increases by 15.21%and 9.86%respectively.When the shear angle decreases from 60°to 30°,the bearing capacity of the new twist bolt and the traditional bolt increases by 13.37%and 18.56%respectively.[Conclusion]The result show that through the evaluation of the two parameters of bearing capacity and effective deformation rate,the bearing capacity and deformation resistance of the new twist bolt are improved compared with the traditional bolt.Under the same anchorage length and shear angle,when the bearing capacity is the same,the deformation resistance of the new twist bolt is better than that of the traditional bolt.When the deformation resistance is the same,the bearing capacity of the new twist bolt is better than that of the traditional bolt.The consistency of the simulation result verifies the validity of the test result.