【摘要】 大跨度斜拉桥通常采用漂浮或半漂浮体系,易导致其在地震作用下梁端位移过大,可采用液压黏滞阻尼器等限位装置约束这种位移,目前阻尼器的设计多为针对远场地震作用而较少研究近场地震作用。但在实际工程中,经常会碰到近断层地质条件,这种近断层地质会引起近场地震。与远场地震相比,近场地震具有短持时、高能量脉冲运动的特征,对结构产生较强的破坏力,因此针对远场地震设计的阻尼器的工作性能,以及阻尼器参数调整等问题都值得研究。以榕江特大桥为工程背景,研究半漂浮体系斜拉桥在近远场地震作用下的地震响应;通过结构非线性时程分析,研究不同阻尼系数和速度指数对近场地震响应的控制效应;根据榕江桥伸缩缝型号以及阻尼器自身的地震响应特点,确定阻尼器设计参数。更多还原

【Abstract】 The large displacement usually takes place at the end of the beam in the cable-stayed bridges because of the floating or semi-floating systems,and the viscous damper is used in the long-span bridges to limit the displacement.However,the damper is usually designed based on the far-field earthquake without taking into account the near-fault earthquake.In the actual project,we usually encountered the geological fault which could cause the near-fault earthquake.The near-fault earthquake is characterized by short duration,high-energy pulse movement and strongly destructive performance compared with the far-field earthquake.Issues that should be discussed are whether the working performance of the damper designed for the far-field earthquake is still good and the parameters should be adjusted in the near-fault earthquake.Rongjiang cable-stayed bridge in Guangdong was taken as an example to study the seismic response of cable-stayed bridge with semi-floating system in near-fault and far-field earthquake.Through the structural nonlinear time history analysis,we could study the response control effect when using different damper coefficients and velocity indexes in the near-fault earthquake.According to the expansion joints model and the damper response characteristics,the design parameters of the damper were determined.更多还原