An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the...An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. Closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. Comparison with results from finite element （FE） analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.展开更多
调频气压液柱阻尼器(tuned liquid column gas damper,TLCGD)是一种从调频液柱阻尼器发展而来的新型而有效的结构减震装置。在U/V形阻尼器液柱上加上封闭式气压不仅增加了它的使用范围,使频率扩大到5Hz,并且提高了结构的有效阻尼。由广...调频气压液柱阻尼器(tuned liquid column gas damper,TLCGD)是一种从调频液柱阻尼器发展而来的新型而有效的结构减震装置。在U/V形阻尼器液柱上加上封闭式气压不仅增加了它的使用范围,使频率扩大到5Hz,并且提高了结构的有效阻尼。由广义Bernoulli方程推导出液体在管道中的运动方程并等价线性化。本文分析了非对称结构平移-扭转耦联振动的动力特性。当结构在地震和强风作用下发生以平移为主的动力反应,该阻尼器的最佳位置使到速度中心的距离最大。通过振型优化,Den Hartog公式得到阻尼器的最优参数(阻尼比和调谐频率比),考虑邻近多个振型的相互影响,状态空间优化使得结果更为合理。用1个3层的偏心结构作为算例,进行优化计算。数值结果表明,这种优化方法得到的参数使得调频气压阻尼器对结构的平动-扭转反应起到较好的减振效果。展开更多
基金U.S. Federal Highway Administration Under Grant No. DTFH61-98-C-00094U.S. National Science Foundation Under Grant No. EEC-9701471
文摘An analytical method to study the seismic response of a bridge pier supported on a rigid caisson foundation embedded in a deep soil stratum underlain by a homogeneous half space is developed. The method reproduces the kinematic and inertial responses, using translational and rotational distributed Winkler springs and dashpots to simulate the soil-caisson interaction. Closed-form solutions are given in the frequency domain for vertical harmonic S-wave excitation. Comparison with results from finite element （FE） analysis and other available solutions demonstrates the reliability of the model. Results from parametric studies are given for the kinematic and inertial responses. The modification of the fundamental period and damping ratio of the bridge due to soil-structure interaction is graphically illustrated.
