伍家岗大桥隧道锚三维地质力学模型试验研究

发布时间：2018-04-27 06:08

本文选题：地质力学 + 伍家岗大桥　；参考：《岩石力学与工程学报》2016年S2期

【摘要】：基于宜昌伍家岗大桥隧道锚工程区的特定地质条件,采用室内三维地质力学模型试验技术,通过后推超载的方法,研究锚塞体与围岩从加荷到破坏的整个过程与整体稳定性。依据相似理论,按照1∶40大比尺对锚塞体及不同岩层的岩体力学特性进行相似模拟,研究锚塞体与围岩的联合受力变形特征、失稳破坏过程、破坏形态以及超载能力,对其整体稳定安全度进行评价。通过分析隧道锚在设计荷载和超载作用下的变形特征及裂缝产生、扩展及汇通的全过程规律,研究隧道锚变形破坏机制及其与围岩联合承载的夹持效应。试验结果表明:在设计荷载作用下,锚体及围岩后表面变形曲线呈双峰形对称,以对称中心向四周呈马鞍形衰减扩散,前表面变形曲线与后表面相似,后表面变形大于前表面变形,隧道锚与围岩体处于弹性阶段;在多倍设计荷载超载条件下,锚塞体与围岩相互作用,共同抵抗外力,形成夹持效应,锚体周边1.0~1.5倍后锚面宽度范围内的围岩变形量较大,综合分析认为隧道锚的超载稳定系数取9.0。
[Abstract]:Based on the specific geological conditions in the Anchorage area of Wujiagang Bridge Tunnel in Yichang, the whole process and overall stability of anchor plug and surrounding rock from loading to failure are studied by means of the laboratory three-dimensional geomechanical model test technique and the method of backstepping overload. According to the similarity theory, the rock mass mechanical characteristics of anchor plug and different rock layers are simulated by using 1:40 large scale, and the combined deformation characteristics, failure process, failure form and overload capacity of anchor plug and surrounding rock are studied. The overall stability and safety degree are evaluated. By analyzing the deformation characteristics of tunnel anchor under the action of design load and overload and the law of the whole process of crack generation, expansion and confluence, the mechanism of tunnel anchor deformation and failure and the clamping effect of tunnel anchor combined with surrounding rock are studied. The experimental results show that the deformation curve of the back surface of the anchor body and surrounding rock is bimodal symmetry under the action of design load, and the front surface deformation curve is similar to that of the rear surface. The deformation of the rear surface is larger than that of the front surface, the tunnel anchor and surrounding rock are in the elastic stage, and under the condition of multiple design load overload, the anchor plug and the surrounding rock interact together to resist the external force and form the clamping effect. The surrounding rock deformation is larger in the width range of the anchor surface after 1.0 ~ 1.5 times around the anchor body. The comprehensive analysis shows that the stability coefficient of tunnel anchor is 9.0.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;三峡大学三峡库区地质灾害教育部重点实验室;长江三峡勘测研究院有限公司;
【基金】：国家自然科学基金资助项目(51579017,51479102) 长江科学院中央级公益性科研院所基本科研业务费项目(CKSF2016008/YT)~~
【分类号】：U448.25

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