中文摘要：

以西安地裂缝F6和F6’长安立交段＂y＂形地裂缝场地为背景,对＂y＂形地裂缝场地主次裂缝地震响应差异开展1∶15的振动台模型试验研究。试验结果表明,El Centro波激励下：①主、次地裂缝两侧的响应加速度放大系数Ki,j均随激励的增大整体上呈减小趋势,这种变化趋势在激励加速度峰值为300Gal时出现拐点;主地裂缝底部处的放大系数大于次裂缝同深度处的放大系数;主、次裂缝顶部和中部的加速度响应差异不明显。②底部加速度响应远离主、次裂缝均明显增强;激励加速度峰值≤200Gal时,中部加速度响应远离主、次裂缝均明显衰减,而顶部加速度响应远离主裂缝反而增强;主、次地裂缝加速度响应距离裂缝的衰减规律差异不明显。③主、次地裂缝顶部的下盘加速度响应均大于上盘,但底部的上盘加速度响应均大于下盘,这种上下盘效应随激励的变化趋势不明显,与主、次地裂缝的相关性也不明显。

英文摘要：

Based on the sites with y-shape ground fissure near the Chang＇ an overpass in Xi＇ an city where the ground fissures are F6 and F6 ＇ , a shaking table test with the scale of 1 ： 15 was carried out to study the seismic response difference between primary and secondary ground fissures for the sites with y-shape ground fissure. By using E1 Centro wave, results are achieved as follow. Firstly, the amplification coefficients of response acceleration for two sides of primary and secondary ground fissures decrease generally with the increase of exciting peak acceleration, but an inflection point appears at 300Gal of excitation peak acceleration. The amplification coefficient of primary ground fissure at the bottom is larger than that of secondary ground fissure, while the difference in response accelerations on the top and middle of primary and secondary ground fissures is not significant. Secondly, the acceleration responses at the bottom may obviously be strengthened with departing the primary and secondary ground fissures. Before the exciting peak acceleration reaches 200Gal, the acceleration response on the middle may be attenuated with departing the primary and secondary fissures, but this regularity is reversed on the top of primary ground fissure. The difference in decaying trend of acceleration response between primary and secondary ground fissures is not remarkable. Thirdly, the acceleration response of footwall on the top of primary and secondary ground fissures is larger than that of hanging wall, but this regularity is reversed at the bottom of primary and secondary ground fissures. With the exciting acceleration, the effect of hanging wall and footwall is not obvious and its correlation with primary and secondary ground fissures is not obvious either.