Constitutive models for sands under dynamic loading and constitutive parameters estimated based on SPT blow count N

动载砂体本构模型及基于SPT打击次数N估计的本构参数

基本信息

批准号：
17560442
负责人：
OHTA Hideki
金额：
$ 2.24万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560442/
关键词：
elastic-plastic constitutive model numerical analysis constant volume triaxial test SPT blow count N computer simulation field monitoring parameter estimation procedure dynamic analysis 等体積3軸試験

项目摘要

Two world-wide well known elastic-plastic constitutive models, the Original Cam Clay model and the Modified Cam Clay model, are extended into anisotropic forms applicable to Ko-consolidated natural soil deposits and further extended into forms appropriate to describe the soil behaviour under repeated loading by using the concepts both of extended sub-loading surface and super-loading surface proposed by Hashiguchi et al (1998) and Asaoka et al (2002) respectively. Examination of these two extended models from the theoretical and numerical points of view indicates that they are employable in engineering practice under limited conditions and suggests the need of developing a family of constitutive models applicable to wider variety of sandy soils. The newly developed family of models includes the Original and Modified Cam Clay models and is found to be applicable to wide variety of natural soil deposits.Undisturbed block samples of dense fine sand taken from a tunneling site are subjecte … More d to a series of constant volume triaxial tests under very high confining pressure. The constitutive parameters obtained from the triaxial tests are carefully compared with the blow count N obtained from the Standard Penetration Tests carried out at the tunneling site aiming at correlating the blow count N with the parameters needed in constitutive models. Confirmation of the relationship between the blow count N and undrained shear strength of sand empirically proposed by Nishigaki et al (1974, 1980) is one of the aims.A procedure of parameter estimation for sandy deposits based on the blow count N from the SPT is thus developed and examined how it works in the engineering practice by employing in a computer simulation of a deep excavation work carried out at a site of sandy deposit. The results obtained from this trial computer simulation using a soil/water coupled finite element code incorporating the newly developed constitutive model are found to be satisfactory by comparing with monitored bending moment and deformation of sheet pile wall installed in the sandy deposit being excavated. It is concluded that the constitutive parameters of sandy deposits for which the SPT blow count N is often the sole available information on mechanical properties can be estimated based primarily on the blow count N and applicable in engineering practice. Less

两个世界知名的弹塑性本构模型，原始 Cam Clay 模型和修正 Cam Clay 模型，被扩展为适用于 Ko 固结天然土沉积物的各向异性形式，并进一步扩展为适合描述重复作用下土体行为的形式。分别使用 Hashiguchi 等人 (1998) 和 Asaoka 等人 (2002) 提出的扩展子加载面和超级加载面的概念进行加载。从理论和理论方面检验了这两个扩展模型。数值观点表明它们在有限条件下可用于工程实践，并表明需要开发适用于更广泛的沙质土壤的本构模型系列。新开发的模型系列包括原始模型和修改后的 Cam Clay 模型。发现适用于各种天然土壤沉积物。从隧道开挖工地采集的致密细砂原状块样品在非常高的围压下进行了一系列恒体积三轴试验，从这些中获得了本构参数。将三轴试验与在隧道开挖现场进行的标准贯入试验中的打击次数 N 进行仔细比较，旨在将打击次数 N 与本构模型所需的参数相关联，以确认所获得的打击次数 N 与不排水剪力之间的关系。 Nishigaki 等人 (1974, 1980) 根据经验提出的沙子强度是目标之一。基于 SPT 的打击计数 N 的沙土参数估计过程为因此开发并检验了它在工程实践中的工作原理，通过在沙质沉积物现场进行了深基坑挖掘工作，使用了土/水耦合有限元代码并结合了新的计算机模拟试验获得了结果。通过与开挖砂质沉积物中安装的板桩墙的弯矩和变形监测结果进行比较，发现所开发的本构模型是令人满意的，得出结论，SPT打击次数N经常用于砂质沉积物的本构参数。关于机械性能的唯一可用信息可以主要根据打击次数 N 进行估计并适用于工程实践。

项目成果

期刊论文数量（23）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Constant Volume Shear Behavior of Sandy Soils under High Confining Pressure

高围压下砂土的定容剪切特性

DOI：
发表时间：
2006
期刊：
Journal of Geotechnical Engineering (Japan Society of Civil Engineers) Vol.62, No.4
影响因子：
0
作者：
Minoru Sakaue;Tsugio Yoshida;Katsumi Yamashita;Futoshi Maegawa;Syohei Katayama;Hideki Ohta
通讯作者：
Hideki Ohta

Shaking table tests on the lateral response of a pile buried in liquefied sand