渡槽结构横向动力响应分析

结合某渡槽安全鉴定工作,建立单跨渡槽结构在设计水位和无水两种工况下的ANSYS三维有限元模型。选用Housner流-固耦合模型模拟了槽内水体与槽体侧壁之间的相互作用,并设定槽墩高度为8.3,10.3,12.3和14.3 m,分别进行模态分析和动力响应分析,以观察在不同槽墩高度下渡槽结构的动力响应(应力、位移和速度)变化。分析结果表明:渡槽结构在设计水位工况下的自振频率小于结构在无水工况下的自振频率;随着槽墩高度的增加,结构在设计水位工况和无水工况下的自振频率均呈减小的趋势,而槽墩顶部、槽体跨中及槽体顶部关键点处的动力响应值有总体增大的趋势;但渡槽结构不同位置的响应值不同,在地震作用下,高墩渡槽的动力响应值总体大于矮墩渡槽的动力响应值。

Analysis of transverse dynamic response for aqueduct structure

For safety appraisal of an aqueduct, an ANSYS three dimensional finite element model of a single span aqueduct structure has been developed with design water level and without water. The fluid solid interaction Housner model is selected to simulate the interaction between water and the aqueduct wall and different pier heights of the aqueduct are set: 8.3 m, 10.3 m, 12.3 m, 14.3 m respectively. The dynamic response of the aqueduct structure under different pier heights (stress, displacement, velocity) based on modal analysis and dynamic analysis is observed. Analysis results show that the natural vibration frequencies of the aqueduct structure under the design water level are less than those without water. With increase of the pier height of the aqueduct, the frequencies of the structure show the trend of decrease; the dynamic response values of the key points of the top of the pier, the mid span and the top of the mid span have the tendency of increase; however, the dynamic response values of the different position of the aqueduct structure are different, therefore, the dynamic response values of the high pier aqueduct is generally greater than that of the short pier aqueduct under the practical conditions of earthquake.