大型基础等效输入地震波研究

Study of the equivalent input seismic waves on the large-scale foundation

提出了一种考虑土与结构相互作用的"等效输入"概念,所谓等效输入就是采用合理的方法获得基础顶面的地震动,认为此地震动已充分考虑土与结构相互作用,可以作为抗震设计中刚性地基假定下的输入地震动。这种方法可以把开放体系中的动力问题转换到封闭系统中,这样既可以利用传统的刚性地基假设,又考虑了土与结构相互作用。用此方法对带箱形基础的框架结构模型进行计算,验证了等效输入的计算精度。

A concept of ＂equivalent input seismic waves＂ considering SSI is put forward. The ＂equivalent input＂ is the seismic ground motion of foundational top obtained with a reasonable approach, and the seismic ground mo- tion is considered as it had taken the SSI into full account, so it can be used as input ground motion under the as- sumption of rigid foundation in seismic design. This method can convert the dynamic question of open system into closed system, so it can both make use of the traditional assumption of rigidi-foundation and take the soil-structure interaction into account. In this paper, the calculation accuracy of the equivalent input is verified by a frame with box foundation.