淤泥质地层地铁站深基坑施工过程变形规律分析  

Analysis of Deformation Laws During the Construction Process of Deep Foundation Pits for Subway Stations in Silty Layer

作　　者：赵月 李贵阳 秦龙飞 ZHAO Yue;LI Guiyang;QIN Longfei(Shandong Rail Transit Survey and Design Institute Co.,Ltd.,Jinan,Shandong 250000,China)

机构地区：[1]山东轨道交通勘察设计院有限公司,山东济南250000

出　　处：《黑龙江交通科技》2024年第7期129-132,137,共5页Communications Science and Technology Heilongjiang

摘　　要：淤泥质地层具有水量大、高触变性、强度低等特性,该地层中地铁车站深基坑施工过程中容易发生基坑变形过大、失稳等问题。为此,以南京地铁大校场站为依托,通过在基坑周边布设监测点,获得了基坑动态施工过程中支护桩桩顶垂直位移、横向位移以及内支撑轴力规律。并通过有限元软件建立三维基坑模型,模拟了基坑施工过程,对比监测结果与数值结果,以验证三维模型的正确性。最后,通过对比土体HS本构和HSS本构模型的计算结果,明确了更适合软土地层基坑开挖分析的本构模型。研究结果表明,基坑开挖过程中桩顶垂直、横向位移均随施工过程逐渐增大,累计位移均在预警值范围以内;HSS能更好地反映淤泥质土小应变范围内特性,更适合淤泥质土层基坑分布开挖的变形特性分析。Due to the characteristics of high water content,high thixotropy,and low strength,the silty layer is prone to problems such as excessive deformation and instability of the deep foundation pit during the construction of subway stations in the modified soil layer.Therefore,based on the Daxiaochang Station of Nanjing Metro that in a silty layer,obtains the vertical displacement,lateral displacement,and internal support axial force laws of the support pile top during the dynamic construction process of the foundation pit by monitoring the surrounding area of the foundation pit.And a three-dimensional foundation pit model was established using finite element software to simulate the construction process of the foundation pit.The monitoring results were compared with numerical results to verify the correctness of the three-dimensional model.Finally,by comparing the calculation results of soil HS constitutive model and HSS constitutive model,a more suitable constitutive model for soft soil layer excavation analysis was identified.The research results indicate that during the excavation process of the foundation pit,the vertical and horizontal displacement of the pile top gradually increases with the construction process,and the cumulative displacement is within the warning value range;HSS better reflects the characteristics of muddy soil within a small strain range,and is more suitable for the deformation characteristics of excavation in muddy soil foundation pits.

关 键 词：淤泥质土层 地铁车站 现场监测 有限元模拟 受力变形 

分 类 号：U231.3[交通运输工程—道路与铁道工程]