考虑开挖应力路径深基坑顺逆结合施工支护变形分析  

Analysis of deformation of supports for deep foundation pit cut with integration of bottom-up and top-down methods considering excavation stress path

作　　者：张坤勇[1,2] 张梦 聂美军 孙斌[2] 刘江涛 ZHANG Kun-yong;ZHANG Meng;NIE Mei-jun;SUN Bin;LIU Jiang-tao(Key Laboratory of Geotechnical and Dam Engineering of the Ministry of Education,Hohai University,Nanjing,Jiangsu 210024,China;Institute of Geotechnical Engineering,Hohai University,Nanjing,Jiangsu 210024,China;China Railway(Shanghai)Investment Group Co.,Ltd.,Shanghai 200135,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210024 [2]河海大学岩土工程科学研究所,江苏南京210024 [3]中铁(上海)投资集团有限公司,上海200135

出　　处：《中国港湾建设》2023年第3期29-37,共9页China Harbour Engineering

基　　金：国家自然科学基金青年科学基金项目(51908278);江苏省高校自然科学基金面上项目(19KJD410002)。

摘　　要：为减少地下空间开发时对周围环境的影响,软土地区深基坑工程施工中需严格控制支护变形。以长江漫滩软土地区某深基坑开挖工程为依托,针对原状土样,开展考虑基坑开挖过程的典型应力路径试验,分析土体开挖条件下的应力变形规律,确定关口太田本构模型的计算参数。建立考虑施工过程的三维有限元模型,分别对顺作法、逆作法和顺逆结合法进行数值模拟,分析顺逆结合法的基坑位移,将顺逆结合法的支护结构、基坑土体变形计算值与实测值进行比较,分析并对比3种不同施工方法对地连墙水平位移、坑周土体变形位移、施工工期的影响。相对顺作法和逆作法,顺逆结合工法能控制长江漫滩软土地区基坑变形,并具有工期和施工成本优势。In order to reduce the influence of underground space development on the surrounding environment,deformation of supports should be strictly controlled in the construction of deep foundation pits in soft soil area.Based on the excavation of a deep foundation pit in the soft soil area of the Changjiang River floodplain,typical stress path tests considering the foundation pit's excavation process were carried out for undisturbed soil samples.The law of stress deformation of soil during excavation is analyzed,and the calculation parameters of Ohta-Sekiguchi constitutive model are determined.A three-dimensional finite element model that takes into account the construction process is built to numerically simulate of the bottom-up construction method,the top-down construction method and the integration of bottom-up and top-down construction method.The displacement of the foundation pit cut with the method integrating bottom-up and top-down construction is analyzed,and the calculated deformation of the supporting structure and the foundation pit soil with the method integrating bottom-up and topdown construction is compared to the observed values.The influence of the three different construction methods on the horizontal displacement of diaphragm walls,deformation and displacement of soil around the foundation pit and the construction duration is analyzed and compared.Compared with the bottom-up construction method and the top-down construction method,the integration of bottom-up and top-down construction method can control the deformation of a foundation pit in the soft soil area of the Changjiang River floodplain,and has the advantage of construction period and cost.

关 键 词：深基坑 关口太田模型 顺逆结合法 变形控制 

分 类 号：U655.544[交通运输工程—港口、海岸及近海工程] TU43[交通运输工程—船舶与海洋工程]