结构-土-结构体系动力特性的模型实验

为研究邻近结构对土-结构体系动力特性的影响，基于弹性相似律，制作了框架结构在刚性基础（RF）、单一结构土-结构相互作用（SSI）和结构-土-结构相互作用（SSSI）的缩尺模型.采用脉冲激励方法识别出三个模型的频率、模态和阻尼比，并与原型有限元计算结果相比较.实验和数值计算结果表明：相应于SSI体系的模态，SSSI体系的模态成对出现，两阶模态的频率接近而相位相反，且SSI体系相应模态的频率位于这两阶频率之间；由于相邻结构的影响，SSSI体系基础的竖向位移和倾覆转角进一步加强.

Model test of the dynamic characteristics of a structure-soil-structure system

Based on the elasticity similitude law,three scaled models,including a frame structure with rigid foundation(RF),soil-structure interaction(SSI) with only one structure and structure-soil-structure interaction(SSSI),were constructed to investigate the effects of neighborhood structures on the dynamic characteristics of the soil-structure system. Then,the impulse excitation method was used to identify the frequencies,mode shapes,and damping ratios of the three models. All of the identified parameters were compared with those of prototypes by the finite element method. Test and numerical results show that there are two natural modes of SSSI,whose frequencies are close but phases are opposite corresponding to each mode of SSI. Moreover,the natural frequency of SSI will be in the interval of the corresponding two frequencies of SSSI. The vertical and rocking displacements increase in the SSSI system due to the effects of neighborhood structures. The scale factors of frequencies between prototypes and models agree with the similitude law.