洋流作用下水中悬浮隧道失稳判据的研究  

On the Instability Criteria of Submerged Floating Tunnel under the Action of Sea Current

作　　者：秦银刚[1] 周晓军[1] 

机构地区：[1]西南交通大学土木学院,成都610031

出　　处：《现代隧道技术》2009年第3期27-32,共6页Modern Tunnelling Technology

基　　金：国家自然科学基金资助项目(编号:10572121);霍英东教育基金资助项目(编号:94024)

摘　　要：根据水下悬浮隧道的主要特征,将水下悬浮隧道管段简化为两端简支梁力学模型。从水中悬浮隧道受力状态分析,推导了圆形截面形式悬浮隧道在涡激力作用下,做垂直于来流方向振动的微分方程。采用平均法对振动微分方程求解,得到了悬浮隧道在定常流状态下的幅频关系。建立定常振幅失稳的双尖点突变模型,导出了其失稳判据。根据失稳判据确定了在其他条件不变的情况下洋流的临界流速。研究结果表明,水下悬浮隧道的失稳不仅取决于洋流速度和涡泄频率,而且还与悬浮隧道结构尺寸、材料性质等有关。A submerged floating tunnel can be simplified as an Euler-Bernulli beam model and simply-supported at both ends according to its main characteristics. Vibration differential equation for the SFT with circular cross-section under the action of vortex-excited forces with its motion perpendicular to the current direction can be deducted by analyzing the submerged floating tunnel＇s behavior. The system＇s amplitude-frequency relation under invariable condition can be acquired by using the average method to solve the vibration differential equation. The unstability criteria have been worked out by establishing the catastrophic model of double cusp for the unstability of the amplitude under invariable condition. The critical safety velocity of the current has been confurned according to the unstability criterion. Research results indicated that the unstability of the SFT is not only dependent on the velocity of the sea current and the vortex releasing frequency, but also related to SFT＇s structural seizes and material properties..

关 键 词：悬浮隧道 涡激 失稳 双尖点突变 判据 

分 类 号：U459.5[建筑科学—桥梁与隧道工程]