隧道分部开挖的围岩松动区演变分析

发布时间：2019-01-21 10:36

【摘要】：以乌蒙山二号四线铁路隧道为工程背景,通过数值模拟手段对比研究分部开挖与一次成洞的松动区形态和大小差异,再结合现场测试结果,分析隧道分部开挖的松动区演变规律。结果表明:一次成洞松动区范围要普遍大于多部开挖的最终松动区范围,最大径向松动深度高出12.6%,最小径向松动深度高出41.2%;在松动区分布形态上,一次成洞表现为左右基本对称,多部开挖具有一定的不对称性,且多部开挖基本是从拱顶到边墙部位依次减小,而一次成洞则呈"拱顶拱脚拱肩边墙"的分布形式。多部开挖时,先挖部分的松动区随着后续开挖部的推进有所增加,后挖部对先挖部的影响表现为:"上下关系"强于"左右关系";另一方面,左右对称位置后挖侧松动区略大于先挖侧,说明先挖部对后挖部亦有劣化作用;其最终松动区是各开挖部相互影响和发展的结果,体现过程相关性。
[Abstract]:Taking the Wumengshan No. 2 railway tunnel as the engineering background, the difference of the loosening zone shape and size between the partial excavation and the once formed tunnel is studied by means of numerical simulation, and the field test results are combined. The evolution law of loose zone in tunnel excavation is analyzed. The results show that the area of single cavern loosening zone is generally larger than that of the final loosening zone of multiple excavations, the maximum radial loosening depth is higher than 12.6, and the minimum radial loosening depth is higher than 41.2 percent. In the distribution of loosening zone, the primary cavern is symmetrical to the left and right, and the excavation of many parts has some asymmetry, and the number of excavations decreases from the arch top to the side wall in turn. And once the hole is a "arch foot arch shoulder side wall" distribution form. With the advance of the subsequent excavation, the loosening zone of the first excavation part increases, and the influence of the later excavation part on the first excavation part is as follows: the "up-and-down relationship" is stronger than the "left and right relationship"; On the other hand, the loosening zone of the left and right symmetrical position is slightly larger than that of the first excavation, which indicates that the first excavation has a deterioration effect on the latter, and the final loosening area is the result of the interaction and development of each excavation, which reflects the correlation of the process.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;西南交通大学土木工程学院;
【基金】：国家自然科学基金青年科学基金项目(51208437) 铁道部科技研究开发计划项目(2010G016-H) 中央高校基本科研业务费专项资金项目(SWJTU12BR039)
【分类号】：U451.2

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