大断面高含水率黄土隧道数值计算

发布时间：2018-04-03 19:35

本文选题：黄土隧道　切入点：宝兰客专　出处：《科学技术与工程》2017年33期

【摘要】：针对宝兰线大断面高含水率黄土隧道施工,通过对不同埋深及不同含水率情况下的进尺、开挖步序、核心土长度、竖撑形式、封闭距离等工况进行数值计算。通过变形结果对比分析可知:在黄土隧道中,随着开挖进尺长度的增加,拱顶及拱脚沉降量也相应增大;但增加的幅度有限。低含水率下的开挖变形受进尺影响较高含水率更为明显。核心土对控制变形非常明显,在高含水率中效果更为明显。核心土长度为5 m时,对沉降控制最为有利,能够减小沉降10%~20%;其中含水率越高越明显。核心土长度大于5 m后,对控制变形的作用将减小。竖撑形式对沉降的控制作用与埋深关系不大,竖撑减小沉降的作用随着含水率的增加更为明显。仰拱封闭距离对沉降影响非常大,随着仰拱封闭距离的增加,沉降量显著增大。对于黄土隧道,尤其是高含水率的黄土隧道,早封闭对控制沉降变形极为有利。
[Abstract]:In view of the construction of loess tunnel with large section and high moisture content in Baolan Line, the numerical calculation is carried out under the conditions of different buried depth and different moisture content, such as advance, excavation sequence, core soil length, vertical bracing form, closed distance and so on.Through the comparison and analysis of deformation results, it can be seen that in loess tunnel, with the increase of the length of the length of the excavation, the settlement of the arch roof and the arch foot increases correspondingly, but the increase range is limited.The excavation deformation under low water content is more obviously affected by the advance scale than the high water content.The core soil can control the deformation obviously, and the effect is more obvious in the high moisture content.When the core soil length is 5 m, the settlement control is most favorable, and the settlement can be reduced by 10 ~ 20%, in which the higher the water content is, the more obvious is the water content.When the length of core soil is larger than 5 m, the effect of controlling deformation will be reduced.The controlling effect of vertical brace on settlement is not related to the depth of buried, but the effect of vertical brace on reducing settlement is more obvious with the increase of water content.The close distance of the inverted arch has a great influence on the settlement, and with the increase of the closed distance of the inverted arch, the settlement increases significantly.For loess tunnel, especially loess tunnel with high moisture content, early closure is very beneficial to control settlement deformation.
【作者单位】：中铁西南科学研究院有限公司;中铁第一勘察设计院集团有限公司;
【基金】：中国中铁科学研究院有限公司青年基金(2015-KJ021-Z021-02)资助
【分类号】：U455.4

【相似文献】