西安地铁明挖黄土隧道湿陷变形工程特性分析

发布时间：2018-06-22 05:33

本文选题：黄土隧道 + 浸水入渗　；参考：《地下空间与工程学报》2014年S1期

【摘要】：黄土隧道围岩的湿陷变形引起衬砌结构不均匀沉降,将对隧道的安全运行构成威胁。以西安地铁4号线明挖黄土隧道工程为背景,针对典型地层结构建立有限差分数值模型,首先,依据场地探井自重湿陷量计算结果反演得到饱和状态下的土性参数。然后,模拟隧道基坑开挖、围护结构支护、隧道结构施工和基坑回填,以及可能的浸水入渗地下水位上升作用,分析了隧道黄土围岩不同浸水条件下黄土地基的湿陷变形及附加应力变化。进而,得到了黄土隧道区间湿陷变形引起的不均匀沉降,以及隧道地基黄土湿陷压缩应力条件的变化规律。分析表明,浸水入渗作用下隧道的湿陷压缩应力及湿陷变形较大,地下水位上升作用下隧道的湿陷压缩应力及湿陷变形较小,总变形甚至会出现回弹。
[Abstract]:The collapsing deformation of surrounding rock of loess tunnel causes uneven settlement of lining structure, which will threaten the safe operation of the tunnel. Based on the project of open excavation loess tunnel of Xi'an Metro Line 4, a finite difference numerical model is established for typical formation structure. Firstly, the soil parameters under saturated condition are obtained by inversion of the calculation results of gravity collapsibility of the site exploration well. Then simulate the excavation of the tunnel foundation pit, the retaining structure, the construction of the tunnel structure and the backfill of the foundation pit, as well as the possible increase of the underground water level. The deformation of collapsibility and the change of additional stress of loess foundation under different soaking conditions of loess surrounding rock of tunnel are analyzed. Furthermore, the uneven settlement caused by the collapsing deformation in the loess tunnel and the variation law of the compression stress conditions of the loess collapsibility in the tunnel foundation are obtained. The analysis shows that the compressive stress and deformation of the tunnel are larger under the action of water infiltration, but the compressive stress and deformation of the tunnel are smaller under the action of rising groundwater level, and the total deformation even appears springback.
【作者单位】：西安理工大学岩土工程研究所;陕西省黄土力学与工程重点实验室;机械勘察设计研究院;
【基金】：国家自然科学基金项目(41272320) 教育部高等学校博士学科点专项科研基金项目(20106118110011)
【分类号】：U452.11

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