建筑物不均匀震陷机理的振动台实验研究

Study on mechanism of earthquakeinduced differential settlement of building by shaking table test

设计实现了结构-地基相互作用的振动台实验,研究了不均匀震陷机理。实验中结构和地基土均匀分布,输入单方向水平加速度时程,得到了结构和土体中加速度、动应力和不均匀震陷的分布并总结了其规律。实验表明:(1)结构基底地震动与自由场相比相差很大,对称位置的竖向加速度和动应力呈反对称分布;(2)反对称的竖向动应力使建筑物产生不均匀震陷。因此,地震波的不规则性对不均匀震陷所起的作用是重要的和不容忽视的。

The shaking table test of SSI is conducted to study mechanism of the earthquakeinduced differential settlement of building due to earthquake in the paper.For symmetrical building and subsoil under one dimensional incidence of the seismic waves, the test results indicate: (1) distribution of the ground motion and the dynamic stress under the building are quite different from those in the free site, and the vertical acceleration and vertical dynamic stress at symmetrical places in the soil are antisymmetrical; (2) the antisymmetrical dynamic stress below the building can produce the differential settlement of the building. Therefore, the irregularity of the seismic waves is an important factor in evaluation of the earthquakeinduced differential settlements of building and subsoil.