A Research on the Structural Dynamics due to Short-Period Surface Waves

利用“伪谱法”编制了水平不规则地基的地震反应及其震害机理分析程序。这些程序包括几个新方法：它可以分别分析SH波和P-SV波的地震反应；在分析边界处能有效吸收人工产生的波；并能清晰地捕捉到水平不规则地面二次产生短周期表面波的过程。此外，我们还开发了一种新的技术，使短周期表面波的产生过程可以在计算机显示器上直观、动态地表达出来。该技术使我们能够详细地解释短周期表面波的传播机制。我们还分析了阵列强震记录，以估计与短周期表面波相关的应变和应力。分析表明，短周期面波产生的大应变会对埋地生命线等多种结构造成地震破坏。最后，我们发表了一份报告，汇总了本研究项目得出的上述成果。

Some computer programs were developed to analyze the earthquake responses of horizontally irregular grounds and their corresponding earthquake damage mechanism using the "Pseudo-Spectral Method." These programs include several new methods: it can analyze seismic responses separately for SH wave and P-SV waves; it can effectively absorb artificially-generated waves at the analytical boundaries; and it can capture clearly the process in which the short-period surface waves are secondarily generated due to horizontally irregular grounds. In addition, we developed a new technique by which the generation processes of short-period surface waves can be visually and dynamically expressed on the display of computers. This technique enables us to interpret detailed propagation mechanism of short-period surface waves. We also analyzed array strong-motion records to estimate strains and stresses related with short-period surface waves. This analysis made it clear that short-period surface waves produce large strains leading to earthquake damage of various kinds of structures such as buried life-line structures. Finally we published a report to compile the above outcomes derived by this research project.