摘要
人工合成地震波(一般用地震动加速度时程)是通过强度包络函数来模拟地震波的强度非平稳特性的,因此探讨时程强度包络函数对地震安全性评价工作的影响,具有重要的理论意义和实际应用价值。强度包络函数模型大致分为单峰状和多峰状,其中多峰状强度包络函数可以灵活、简洁地模拟地震波的强度非平稳特性,被广泛应用。本文通过实例,研究强度包络函数霍俊荣模型和Mcguire模型对土层地震反应分析的影响。对于长周期结构,建议采取先计算反应谱不同控制周期处时程强度包络函数值,再分别迭代最终拟合得到加速度时程,此方法合成的加速度时程充分考虑了大震级、远距离潜在震源区的影响,从而不会低估长周期结构的地震动输入能量。地震动时程的零线漂移也是地震波合成的一个重要问题,否则结构动力时程分析的结果是不可靠的,可以采用多项式修正,也可以采用光滑无奇异点强度包络函数模型解决这一问题。
The artificial seismic wave (normally using the earthquake acceleration time history) imitates non-stationary characteristic of seismic wave intensity via intensity envelope function, so it’s of important theoretical significance and actual application value for the influence analysis of time history envelope function in seismic safety evaluation. Intensity envelope function model includes single-peak shape and multi-peaks shape. The multi-peak shape intensity envelope function model can imitate non-stationary characteristic of seismic intensity simply and neatly, which is commonly used. This article researches on analysis of seismic response of soil layer through Huojun- rong Model and Mcguire Model of intensity envelope function. For long-periodic structure, it is suggested that response spectrum time history envelope function values in different control cycles should be calculated first, then iteration is used separately and finally acceleration time history is gotten. Acceleration time history (resulting in this method) considers large-magnitude and long-distance potential seismic source influence, and thus does not underestimate seismic movement of long-periodic structure causing adding energy. Zero drift in seismic movement time history is also an import problem in seismic wave synthesis, and otherwise result data of structure power time history are not trustworthy. Seismic movement time history can use multinomial amendment, and also can use smooth non-singular point intensity envelope function to solve this.
