地铁车站结构振动台试验中模型箱设计的研究
Study on design of test box in shaking table test for subway station structure in soft soil
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摘要: 介绍笔者在对软土地铁车站结构进行振动台模型试验的过程中,在模型箱设计方面遇到的技术难题及其解决途径。主要包括在确定几何相似比时,通过论证分析提出了对量值极大的车站结构长度可行的简化方法,及对原型半无限体场地土的模拟范围;在选定模型箱结构的外形与构造时,借助有限元分析论证了可不与模型土发生共振的箱体构造;对箱体边界,通过对刚性侧壁内衬塑料板使模型土可较好模拟原型土的变形等。上述措施对试验获得成功起到了保障作用,对同类试验也有参考价值。Abstract: This paper describes the technical difficulties and resolutions of the test box design in the shaking table test for subway station structures in soft soil. Based on the results from 3-D FEM dynamic analysis and references, a possible simplified method for the long length of subway station structures is proposed, and the reasonable area to simulate the dynamic behavior of the semi-infinite ground is determined, which are necessary to determine the geometric similarity scale for the test. It is proved by FEM analysis that the proposed shape and structure of the test box can avoid resonance with the model soil.Besides,the model soil can simulate well the deformation of ground by means of putting plastic gasket on the rigid cheek. The above-mentioned measures lay a firm foundation for the success of the test and can be referenced in the similar tests.