振动台试验模型地基土的设计与试验研究

本文在动力相似关系的分析基础之上,设计了一种以锯末为主要成分,用于地基-基础-上部结构动力相互作用振动台试验的模型土。用循环单剪仪对原型土和设计的模型土分别进行了试验,得出了2者的动剪切模量比Gd/Gdm ax和阻尼比λ随动剪应变γd变化的关系曲线,对两种土的动力特性进行了相似对比。试验结果表明,设计的模型土与原型土的动力特性具有较好的相似性。采用等效线性本构模型,给出了原型土和模型土的动力特性参数。对采用本文所设计的模型土进行振动台试验的动力相似问题进行了初步讨论。

Design and experimental study of a model soil used for shaking table test

On the basis of dynamic similitude analysis, a model soil which is mainly composed of sawdust and aimed to be used in the shaking table test of the soil-foundation-structure system is designed. Cyclic simple shear testings have been conducted on the specimens of both the site soil and designed soil, and the curves of dynamic shear modulus ratio G/Gmax and damping ration A versus dynamic shear strain y for both the site soils and the designed model soils are presented. The comparison of these curves between the field soil and the designed model soil is made, which indicates that the dynamic characteristics of those are of good similarity. Both the site soil and the designed model soil regarded as a visco-elastic body are studied by means of an equivalent linear model, and the corresponding parameters are presented. Lastly, the question of dynamic similitude between the prototype system and the model system, using the designed soil as foundation soil of the model system, is discussed generally.