土岩组合地层地铁深基坑土钉墙支护轴力分析  

Axial force analysis of soil nailing wall support for deep foundationpit of subway in soil-rock combination stratum

作　　者：王珂 王立峰 韦康 寿凌超 WANG Ke;WANG Lifeng;WEI Kang;SHOU Lingchao(School of Civil Engineering and Architecture,Zhejiang University ofScience and Technology,Hangzhou 310023,Zhejiang,China)

机构地区：[1]浙江科技学院土木与建筑工程学院,杭州310023

出　　处：《浙江科技学院学报》2021年第5期399-407,共9页Journal of Zhejiang University of Science and Technology

基　　金：浙江省金华市科技局计划项目(0401104117)。

摘　　要：为研究土钉墙支护在土岩组合二元地层地铁深基坑的受力特性,以金华市地铁深基坑秦塘站为背景,通过现场监测、理论分析与有限元数值模拟等方法对土钉墙支护轴力展开研究。首先,根据监测结果分析得到土钉沿钉长方向的轴力分布:在土质相对较差的黏土层中,土钉轴力沿钉长方向分布呈中间大、两头小的形式;在岩土层内,土钉轴力主要集中在钉头附近,轴力相对较小。然后,拟合得到边坡最危险滑裂面在见岩面附近存在拐点。最后,通过Midas GTS NX有限元软件分析得到,随着岩面高度的变化土钉轴力最大值大体呈线性发展。因此,对于土岩组合二元地层,根据岩面深度分布,当见岩面离地表较近时,结合土钉墙被动受力的特点可以适当调整土钉配筋或减少土钉道数;当见岩面离地表较远时,可适当增加土钉长度和土钉道数。研究结果表明,土钉支护在土岩二元地层中能够对土岩界面处土体起到良好的支护作用,这可为后续相似地质条件基坑工程的设计和施工提供一定的参考。In order to probe into the mechanical characteristics of soilnailing wall support in a deep foundation pit of subway in a binary soil-rock combination stratum,the axial force of soilnailing wall support was studied through on-site monitoring,theoretical analysis and finite element numerical simulation by taking the Jinhua subway deep foundation pit Qintang Station as the background.First,according to the analysis of the monitoring results,the axial force distribution of soil nails along the nail length direction was obtained:in a clay layer with relatively poor soil quality,the axial force of soil nails along the nail length direction is distributed in the form of large in the middle and small at both ends;in the rock and soil layer,the axial force of soil nails is mainly concentrated near the nail head,with relatively smallaxial force.Second,the fitting results show that the most dangerous slip surface of the slope has an inflection point near the rock surface.Finally,the analysis of MIDAS GTS NX finite element software reveals that the maximum axial force of soil nailing develops approximately linearly with the change of rock surface height.Therefore,for the soil-rock combination binary formation,the depth distribution of the rock surface is different:when the rock surface is close to the ground surface,the soil nailing reinforcement can be appropriately adjusted or the number of soil nailing can be reduced according to the characteristics of the passive force of the soil nailing wall;when it is far away,the length of soil nails and the number of soil nailing can be appropriately increased.The results show that the soil nailing support in the soil-rock binary stratum can play a good role in supporting the soil at the soil-rock interface,and provide a certain reference for the subsequent design and construction of foundation pit projects with similar geological conditions.

关 键 词：土岩组合 见岩面 土钉轴力 滑裂面 有限元 

分 类 号：TU432[建筑科学—岩土工程]