基于CPTU/SDMT原位测试的软弱土HSS本构模型参数确定方法  

A CPTU/SDMT-based approach to determine the HSS model parameters of soft soils

作　　者：刘松玉[1,2] 蔡国军 赖丰文 黄明 程月红[5] 鲁泰山 LIU Songyu;CAI Guojun;LAI Fengwen;HUANG Ming;CHENG Yuehong;LU Taishan(Institute of Geotechnical Engineering,Southeast University,Nanjing 211189,Jiangsu,China;Nanjing Modern Multimodal Transportation Laboratory,Nanjing 210004,Jiangsu,China;College of Civil Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China;College of Civil Engineering,Fuzhou University,Fuzhou 350116,Fujian,China;ZYF Construction Group Co.,Ltd.,Suzhou 215000,Jiangsu,China)

机构地区：[1]东南大学岩土工程研究所,江苏南京211189 [2]南京现代综合交通实验室,江苏南京210004 [3]安徽建筑大学土木工程学院,安徽合肥230601 [4]福州大学土木工程学院,福建福州350116 [5]中亿丰建设集团股份有限公司,江苏苏州215000

出　　处：《地基处理》2024年第6期531-539,共9页Journal of Ground Improvement

基　　金：国家自然科学基金(42225206,52408356);福建省中青年教师教育科研项目(JAT231002)。

摘　　要：小应变硬化(Hardening Soil-Small,HSS)模型因其能够准确反映土体小应变范围内剪切模量的非线性特性,在地下工程开挖变形计算中得到了广泛应用。软弱土的力学特性易受钻孔取样扰动影响,导致常规室内单元试验标定的HSS本构模型参数存在一定误差。根据原位测试技术确定土体参数可有效避免取样扰动的思路,提出了基于孔压静力触探(Piezocone Penetration Test,CPTU)和地震波扁铲侧胀仪(Seismic Dilatometer Test,SDMT)的HSS模型参数确定方法。将所提方法应用至苏州典型软土地区邻轨深基坑工程中,计算得到了全套HSS模型参数,并分别通过与室内固结压缩-回弹曲线和现场动力波速测试数据进行对比,验证了所提方法的准确性和合理性,进一步将所得参数应用于深基坑开挖变形响应计算。结果表明,邻轨基坑开挖变形计算结果与现场监测数据基本一致,证明了基于CPTU/SDMT原位测试的HSS模型参数确定方法的工程适用性。The Hardening Soil-Small(HSS)model,which effectively captures the nonlinear behavior of the shear modulus of soils within the small-strain range,has been widely used in deformation calculations for underground excavation projects.The mechanical behavior of soft soil is easily affected by sampling disturbance,leading to a larger error for the HSS model parameters calibrated by laboratory tests.For this purpose,this paper presents an approach to determine the HSS model parameters by means of a combination of the Piezocone Penetration Test(CPTU)and the Seismic Dilatometer Test(SDMT),which both well avoid sampling disturbance.The proposed approach was then applied in a typical case of deep excavations laterally adjacent to existing tunnels in soft soils deposited in Suzhou.The full set of HSS model parameters was calculated and verified for accuracy and rationality by comparing with the laboratory consolidation compression-rebound curves and the in-situ dynamic wave velocity profile.Subsequently,the HSS model parameters were employed to numerically calculate the deformation response of deep excavations.The results show that the numerical results of the deformation match well with the field observation,demonstrating the practical applicability of the CPTU/SDMT-based determination approach of the HSS model parameters.

关 键 词：孔压静力触探 地震波扁铲侧胀仪 HSS本构模型 软弱土 地下工程 

分 类 号：TU47[建筑科学—结构工程]