关于圆形浅谷对Rayleigh波的反应的注记——分析方法(英文)

本文采用一个新的分析方法研究了冲积浅谷对平面单频Rayleigh波的稳态反应。谷地的形状是圆的,其深度对半宽的比≤1。将传入谷地以及散射的波表为Fourier-Bessel级数,本文的方法就是建立在这个基础之上。在应用应力和位移的连续条件之前,用有限的Fourier级数来近似自由场运动。研究结果表明,谷地一般放大了入射的地面运动,同时,位移的放大和复杂性决定于入射Rayleigh波的频率以及谷地的形状。

Antiplane SH-deformations near a surface rigid foundation above a subsurface rigid circular tunnel

The problem on the dynamic response of a rigid embedded foundation in the presence of an underground rigid tunnel and subjected to excitation of incident anti-plane SH waves is analyzed.By using the exact analytical solution for the two-dimensional SH-wave propagation in and around both the surface rigid foundation and subsurface rigid tunnel,those aspects of the resulting ground motions that are of special interest and importance for seismic resistant design in earthquake analyses have been examined.The computed amplitudes of the resulting periodic ground motions display a very complicated wave-interference between the surface foundation and underground tunnel that lead to observed standing wave patterns, together with abrupt changes in the wave amplitudes and large amplification of the incident motions.

记录到的强地震动的拟相对速度谱按照震级和局部土质以及地质两种场地分类的经验标定(英文)

根据震级、震源到台站的有代表性的距离、局部土质分类(“岩石”、硬土或深土)和局部地质场地条件(沉积、中等场地或基岩场地),本文提出了拟相对速度谱幅PSV(T)的经验回归方程。本文结果表明,土质分类以及地质场地条件两者在场地特定反应谱幅的标定中都应采用。

关于标绘阈值烈度的注记(英文)

本文提供标绘阈值烈度的一个方法,该烈度超过在随后五十年中强地震动的等危险性谱值。文中阐明,基于等危险性谱(Anderson和Trifunac,1977,1978;Lee,1987)的地震小区划图怎样可用于计算阈值烈度,预期低于该烈度时经工程设计的结构应不发生破坏。阈值烈度图可用于:1.估计一个预测的地震的后果;2.使当地城市与州组织对于一个可能发生的地震的反应最优化。