小应变硬化模型在南京漫滩区深大基坑中的应用研究  

Application of Small Strain Soil Hardening Model in Deep Foundation Pit in Floodplain Area of Nanjing

作　　者：王博文 夏晨 王子安 杨科学 WANG Bowen;XIA Chen;WANG Zian;YANG Kexue(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044;Beijing International Science and Technology Cooperation Base for Urban Transportation Infrastructure Construction,Beijing University of Civil Engineering and Architecture,Beijing 100044;China Tiegong Investment&Construction Group Co.,Ltd.Urban Construction Branch,Beijing 100070)

机构地区：[1]北京建筑大学土木与交通工程学院,北京100044 [2]北京建筑大学城市交通基础设施建设北京国际科技合作基地,北京100044 [3]中国铁工投资建设集团有限公司城市建设分公司,北京100070

出　　处：《北京建筑大学学报》2024年第3期127-136,共10页Journal of Beijing University of Civil Engineering and Architecture

基　　金：国家自然科学基金项目(51708018,51774018);北京市教委科研项目-科技计划一般项目(KM202010016016);北京建筑大学“建大英才计划”项目(JDYC20200308)。

摘　　要：南京长江漫滩地貌土层具有典型的二元结构分布特征,上层各黏性土土质状况较差,软塑、强度低、变形大的高压缩性符合软土定义,并且该土层厚度大、分布广,对工程建设影响较大。针对漫滩区深基坑开挖引起的变形受力问题,以南京龙袍一号初中基坑工程为背景,使用PLAXIS 3D建立有限元模型,土体采用小应变硬化本构模型(HSS模型),模型参数根据现场勘察报告、理论经验,结合南京漫滩区实际情况进行取值。将基坑周边地表沉降变形、土体深层和支围结构水平位移的模拟计算结果与实际监测数据进行对比,结果表明模拟计算结果与实际监测数据趋势相近,数值较为符合。模拟计算结果可以很好地反映出实际的基坑周边地表沉降变形和基坑顶部整体水平位移趋势及变形大小,验证了HSS模型在南京漫滩区基坑工程中应用的可行性及运用经验法取值的合理性。采用的HSS模型及参数可为漫滩区基坑工程研究提供参考。The topographic soil layer of Nanjing Yangtze River flood plain has the typical distribution characteristics of dual structure.The soil quality of the upper layer is poor,and the high compressibility of soft plastic,low strength and large deformation meets the definition of soft soil.Moreover,the soil layer is of a large thickness and wide distribution,which possesess a great influence on engineering construction.Aiming at the deformation force problem caused by deep foundation pit excavation in overshoal area,the PLAXIS,3D as the background of a foundation pit project under construction in Liuhe district,Nanjing,is used to establish a finite element model,and a small strain hardening constitutive model(HSS model)is adopted for soil mass.The model parameters are calculated according to the field investigation report,theoretical experience,and the actual situation of Nanjing overshoal area.The simulation results of surface settlement deformation,soil depth and horizontal displacement of support structure around the foundation pit are compared with the actual monitoring data.The results show that the trend of the simulation results is similar to the actual monitoring data,and the values are in good agreement.The simulation results can well reflect the actual surface settlement deformation around the foundation pit and the overall horizontal displacement trend and deformation size of the top of the foundation pit,and verify the feasibility of applying the HSS model in the foundation pit engineering in the flood beach area of Nanjing and the rationality of using the empirical method.The HSS model and parameters used in this paper can provide reference for the research of foundation pit engineering in flood beach area.

关 键 词：漫滩区 深大基坑 HSS本构 现场监测 数字模拟 

分 类 号：TU447[建筑科学—岩土工程]