波流作用下悬浮隧道动态响应的分析估算

研究目的:悬浮隧道是一种新型水下隧道,由于它长期处于波流作用的环境中,因此研究悬浮隧道在波流作用下的动态响应,是工程设计中不能回避的问题。然而分析波流与悬浮隧道的相互作用,其过程非常复杂,因此寻求一种简捷实用的动态响应估算方法很有必要。研究方法:本文将支撑结构之间的一段悬浮隧道简化为简支梁,利用梁的弯曲振动方程,在考虑结构粘性阻尼和非线性流体阻尼的条件下,采用伽辽金法和数值积分法,对悬浮隧道在波流作用下的动态响应进行了分析估算。研究结果:1阶模态对隧道的响应位移影响最大;当波浪频率与隧道1阶固有频率相等而发生首阶谐振时,隧道1阶模态响应幅值大幅增加。研究结论:隧道断面形式、支承跨度及隧道放置深度对隧道的动态响应有显著影响。

An Analytic Calculation of Dynamic Response for a Submerged Floating Tunnel Subjected to Wave and Current

Research purposes: The submerged floating tunnel (SFT) is an innovative submarine tunnel. As a result of being situated in the natural environment with wave and current actions throughout it is inevitable in designing the project to consider the dynamic response of an SFT under the natural condition. On the other hand, the process of analyzing the interaction of an SFT with the wave and current is so complicated that it is necessary to look for a simplified and practical calculating method to meet the dynamic response. Research methods:In this paper, a free span of an SFT body is simplified as a simple beam. On considering the conditions of the non-linear fluid damping and the structure viscous damping, the dynamic response for an SFT subjected to wave and current is analyzed by virtue of the bending vibration function on simple beam and by means of the Galerkin method and numerical integration. Research results:The results of analyzing calculation show that the influence of the first -order modality on displacement response is the most active, and that the first-order modal response oscillation of tunnel body increases markedly as the wave frequency equals the first-order natural frequency of tunnel and harmonic vibration takes place. Research conclusions:The dynamic response of tunnel is influenced obviously by the shape of tunnel section, the length of supporting span, and the depth of tunnel under water surface.