Shaking Table Test allowing Interpretation of Damage to Structure in terms of Energy Influx and Efflux through Soil-Structure Interface

为了在不使用任何物理地面模型的情况下纳入土壤和结构之间的相互作用，Konagai等人。(1997~1998)提出了一种新的振动台试验方法。在他们的方法中，将适当的土-结构相互作用运动添加到自由场地面运动中，以模拟土-结构相互作用效应。该方法考虑了通常使土-结构体系的总阻尼大于结构本身的辐射阻尼，从而在振动台试验中考虑了土-结构相互作用的影响，从而降低了对振动台性能的要求。这种动力相互作用是一种与地震激励产生并通过土-结构界面传递的能量的流入和流出有关的现象。值得注意的是，流入和流出之间的差异恰恰是储存在结构内的能量，因此，与da…的程度密切相关。为建筑增添更多的魔力。如果在振动台试验中合理地模拟这些相互作用的影响，就可以获得从能量的角度解释原型结构破坏过程所需的信息。该方法最初是在假设土体的线性行为的基础上发展起来的，该方法被扩展为通过等效的线性方法来考虑土体的远场非线性。基础附近产生的非线性通常与大应变和土与基础的分离有关，在本研究中没有考虑到。该方法利用数字信号处理器实时改变土体动力参数。该方法一方面捕捉到了地震过程中土体软化和再硬化的非线性行为，另一方面，由于不需要较重的物理地基模型，因此可以进行更大的上部结构模型试验。较少

With a view to incorporate the interaction between soil and structure without using any physical ground model, Konagai et al. (1997〜1998) introduced a new method for shaking table tests. In their method, appropriate soil-structure interaction motions are added to free-field ground motions to simulate soil-structure interaction effects. The method considers radiation damping which, in general, causes the total damping of a soil-structure system to be greater than that of the structure itself, Thus the incorporation of soil-structure interaction effects in a shaking table test leads to reducing the demands on the capacity of shaking tables. This dynamic interaction is a phenomenon associated with the influx and efflux of energy which is generated by the earthquake excitation and transmitted through the soil-structure interface. It is noted that the difference between the influx and efflux is exactly the energy stored up within a structure, and thus, is closely related to the extent of da … More mage to the structure. If these interaction effects are rationally simulated in shaking table tests, one will obtain the necessary pieces of information for interpreting the failure processes of prototype structures in terms of energy.The method was initially developed with the assumption that soil behaves linearly in the present report, the method is extended to take the 'far field' soil non-linearity into account through an equivalent linear approach. The non-linearity produced in the vicinity of foundations, which is usually associated with large strain and separation between soil and foundation, has not been considered in this study. In this method the dynamic soil parameters are varied in real time by means of a digital signal processor. The method, on one hand, captures the non-linear soil behavior of softening and re-hardening during the course of an earthquake, and on the other hand, allows testing of a bigger superstructure model by obviating the need of a heavy physical ground model. Less