考虑雷诺数效应的大跨度桥梁涡激振动与气动抑振措施研究

As vortex-induced vibration of long-span bridges occurs at low wind speed, this vibration has happened in many bridges during construction and operation, which will influence the construction and the traffic safety, and even lead to the fatigue failure of the bridge. Previous studies have shown that Reynolds number effect can produce important influence on the vortex-induced vibration, but the existing wind tunnel test was typically done with small-scaled model at low Reynolds number, by which the influence of the great Reynolds number difference between test and practical bridge on the results cannot be identified. Using typical sections of long-span bridges as the research object, this subject conducts vortex-induced vibration tests under different Reynolds numbers from low to high, and these tests are carried out with different scale models in the usual wind tunnel ( STU-1 wind tunnel of Shijiazhuang Tiedao University, two test sections of 4.4m×3m and 2.2m×2m) and the large section wind tunnel ( FL-13 wind tunnel of China Aerodynamics Research and Development Center, two test sections of 16m×12m and 8m×6m), which is designed to study the laws of the vortex-induced vibration characteristics of the typical section of long-span bridge varying with the Reynolds number, to obtain the calculation and correction method of the vortex-induced vibration in practical bridge Reynolds number based on the vortex-induced vibration in low Reynolds number, to research the rule of vibration suppression of aerodynamic measures with Reynolds number, aiming at providing experimental and theoretical methods for the wind resistant designing and studying of the vortex-induced vibration of long-span bridges in practical bridge Reynolds number.

大跨度桥梁的涡激振动发生风速较低，很多大桥在建设和运营期间发生过这种振动，影响施工和通车安全甚至导致桥梁的疲劳破坏。已有研究表明雷诺数效应会对涡激振动产生不可忽视的影响，现有的风洞试验研究通常是利用小比例尺模型在低雷诺数下进行试验，无法明确试验和实桥间巨大的雷诺数差别对结果的影响。本项目以大跨度桥梁典型断面为研究对象，通过常规风洞（石家庄铁道大学STU-1风洞，4.4m×3m和2.2m×2m两个试验段）和大断面风洞（中国空气动力研究与发展中心FL-13风洞，16m×12m和8m×6m两个试验段）试验，利用不同缩尺比模型，进行从低到高不同雷诺数下涡激振动试验，研究典型桥梁断面涡激振动特性随雷诺数的变化规律，研究以低雷诺数下的涡激振动为基础，推算实桥雷诺数下涡激振动的计算和修正方法，研究气动措施的抑振效果随雷诺数的变化规律，为大跨度桥梁实桥雷诺数下的涡激振动抗风设计和研究提供试验和理论方法。

大跨度桥梁的涡激振动发生风速较低，很多大桥在建设和运营期间发生过这种振动，影响施工和通车安全甚至导致桥梁的疲劳破坏。已有研究表明雷诺数效应会对涡激振动产生不可忽视的影响，现有的风洞试验研究通常是利用小比例尺模型在低雷诺数下进行试验，无法明确试验和实桥间巨大的雷诺数差别对结果的影响。本项目首先以大跨度桥梁主梁典型断面为研究对象，通过风洞测压、测力试验，系统研究了从低雷诺数到高雷诺数范围内主梁气动力及表面风压分布随雷诺数的变化规律，获得了高、低雷诺数下气动力的修正方法，并明确了雷诺数对主梁气动特性的影响机理；通过风洞测振试验，揭示了大跨度桥梁主梁涡激振动的发生机理及干扰特性，获得了高、低雷诺数下涡激振动的修正方法，及包括栏杆、风嘴等气动措施对涡激振动的影响规律。在此基础上，以斜拉索为研究对象，系统研究了非标准圆截面斜拉索气动特性随雷诺数的变化规律、湍流度对斜拉索气动特性的影响规律、非标准圆截面斜拉索的风致振动特性及波浪形斜拉索的风致振动特性四个方面，得到了基于雷诺数、表面状态、湍流度等影响的大跨度桥梁索杆气动力的精确计算方法及有效的减阻抑振措施。项目取得的研究成果对于大跨度桥梁设计的安全性和经济性具有重要意义，一方面保证了规范要求风速下大跨度桥梁结构的安全，取得了显著的社会效益；另一方面通过优化设计，使得结构更加经济合理，产生了良好的经济效益。