论文部分内容阅读
本文利用二维时域非线性场地地震反应分析程序,针对3个不同的盆地,利用具有不同峰值、不同频谱特性的实际地震记录以不同角度入射作为输入基岩的SH波,共组成513个工况,研究了盆地地表加速度峰值和反应谱随地震波入射角变化的特征和规律,发现地震波入射角对二者均有重要影响。地表加速度峰值放大系数的最大值并非出现在地震波垂直入射(0°)时,而是大致在15°~35°之间,按垂直入射得出的计算结果在某些部位可能偏于不安全;入射角对加速度反应谱的短周期分量(<1s)影响较大,而对其中的长周期分量(>1s)影响较小;在强震作用下盆地土体将发生较强的非线性响应,导致地表加速度放大系数减小;随着梯形盆地坡角的增大,最不利位置有从盆地边缘向盆地中部转移的趋势,同时本文给出了盆地的最不利位置,对工程实践具有一定的参考价值。
In this paper, we use two-dimensional non-linear time-domain seismic response analysis program for three different basins, using the actual seismic records with different peaks and different spectral characteristics at different angles of incidence as the input bedrock SH waves, a total of 513 workers On the other hand, the characteristics and regularities of peak acceleration and response spectrum of the basin with the incident angle of seismic waves are studied. It is found that the incident angle of seismic waves has an important influence on both. The maximum value of the peak amplification factor of surface acceleration is not in the case of vertical incidence (0 °) of seismic waves, but roughly between 15 ° and 35 °. The calculation results obtained by vertical incidence may be unsafe in some places. The incident angle has a great influence on the short-period component (<1s) of the acceleration response spectrum and has little effect on the long-period component (> 1s) of the acceleration response spectrum. Strong earthquakes will occur in the strong earthquakes, Resulting in a decrease of amplification factor of surface acceleration. With the increase of slope angle of trapezoidal basin, the most unfavorable position tends to migrate from the edge of the basin to the middle of the basin. At the same time, the most unfavorable position of the basin is given, which has certain reference to engineering practice value.