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为研究隧道锚–围岩系统的承载特性,依托云南普立特大桥普立岸隧道锚,开展锚塞体不同大小和埋深的室内模型试验研究。试验结果表明,试验荷载作用下和锚塞体接触部位的围岩首先发挥抗剪作用直至到极限状态,锚塞体发生微小变形,然后荷载产生的应力逐步向围岩中扩散,围岩表面出现变形,最终锚塞体位移发生突变,围岩表面出现放射性裂纹。根据锚塞体和围岩表面的荷载–位移曲线以及围岩中的附加应力变化情况,研究了隧道锚–围岩系统的承载力确定方法。针对相似材料中III类围岩黏聚力不满足相似比的情况,提出采用数值仿真的方法对进行畸变修正,得到与原始地质模型匹配的相似模型允许荷载是30f(f为设计荷载),极限荷载是设计50f。研究结果可为大桥隧道锚的修建及类似的工程设计提供参考。
In order to study the bearing characteristics of the tunnel anchor-surrounding rock system and rely on the Anchor of PuLiTai Bridge in PuLiTai Bridge of Yunnan Province, indoor model tests of different sizes and depth of anchor plug body are carried out. The experimental results show that the surrounding rock of the contact part with the anchor body first exerts the shear effect until the limit state is reached under the action of the test load and the anchor body undergoes slight deformation and the stress generated by the load gradually diffuses into the surrounding rock and the surface of the surrounding rock appears Deformation, the final displacement of the anchor plug mutation, rock radioactive surface cracks. According to the load-displacement curve of the anchor body and the surrounding rock surface and the change of additional stress in the surrounding rock, the bearing capacity determination method of the tunnel anchor-surrounding rock system is studied. Aiming at the situation that the cohesion of the surrounding rocks of type III does not satisfy the similarity ratio in similar materials, a numerical simulation method is proposed to correct the distortion. The similar model matching with the original geological model is obtained. The allowable load is 30f (f is the design load) Load is design 50f. The research results can provide reference for the construction of the tunnel bridge anchor and similar engineering design.