Study on Generalized Sealing Relationship for Dynamic Centrifuge Model Tests of Soil-Structure Systems

本研究旨在验证新提出的土结构体系动力离心机模型试验的广义缩尺关系。广义标度关系是1g场和离心机场的标度关系的组合，通过虚拟1g场模型的概念，从而确定了两步标度过程中的标度因子范围。在本项目为期两年的时间里，基于新的模型建模时间，研究了该广义比例关系在桩-土系统和水平地基模型中的适用性，并对桩-土系统进行了离心加速度场为5~50g、几何比例系数为100(=原型/模型)的模型试验。模型模拟结果表明，在离心加速度场小于20g的情况下，桩顶加速度和位移以及桩身弯矩分布的广义比例关系具有较好的适用性。广义缩尺关系对较大的离心机加速度场的适用性仍是一个有待进一步研究的问题。为了研究广义缩尺关系的适用性，在水平地面上进行了模型试验。离心加速度场的范围从1g到70g，比桩-土系统使用的范围要大得多，几何比例因子为100。模型的模拟结果支持瑞克波剪切波速和正弦波加速度响应的广义标度关系的适用性。

This study aims at validating a newly proposed generalized scaling relationship for dynamic centrifuge model tests of soil structure systems. The generalized scaling relationship is a combination of the scaling relationships for 1g and centrifuge fields through a concept of virtual 1g field model and thereby specifies scaling factors band on the two step scaling procedure. Within the period of two years of this project, applicability of this generalized scaling relationship was studied for a pile-soil system and a level ground model based on a new time of modeling of models.Model tests on the pile-soil system were performed with the centrifugal acceleration fields ranging from 5 to 50g with a geometrical scaling factor of 100(=prototype/model). Results of the modeling of models support the applicability of the generalized scaling relationship for acceleration and displacement at the pile top, and bending moment distribution over the pile for the centrifugal acceleration field less than 20g. The applicability of the generalized scaling relationship for a larger centrifugal acceleration field remained a problem to be studied further.Model tests on the level ground were performed in order to focus on a fundamental aspect of the applicability of the generalized scaling relationship. The centrifugal acceleration field ranging from 1g to 70g, that spans a much wider range than that used for the pile-soil system, was applied with a geometrical scaling factor of 100. Results of the modeling of models support the applicability of the generalized scaling relationship for shear wave velocity using a Ricker wave and acceleration response using sinusoidal wave.