城市洪水中人车失稳机理研究

In recent years, the occurrence probability of urban flood caused by abrupt rainstorm has increased, which not only make a growing threat to people, but also cause significant losses to vehicles. Besides, the slipping vehicles may also bring secondary disasters. In this research, both mechanics theory analysis and experiment model are used to study the instability mechanism of people and vehicles in urban flood. Firstly, the collected data are sorted and analyzed to determine the research object and make research plan. Secondly, the instability modes of people and vehicles in floodwaters are proposed, the mechanics models of people and vehicles instability and vehicles slipping are established, and the initiation formula for flooded people and vehicles and slip velocity formula for flood vehicles are deduced. Then, a series of flume experiments on initial velocity for people and vehicle and vehicle slip velocity in floodwaters are conducted. The test data are used to determine relevant parameters and some methods are used to verify the formulae. Finally, instability state for prototype people and vehicles in the urban flood are estimated using the derived formulae, and the hazard rating maps of the people and vehicles in representative city are drawn. Research results can not only provide an important basis for the development of the evacuation scheme and the arrangement of the parking lots, but also improve the existing flood risk assessment methods.

近年来，突发性暴雨导致的城市洪水发生几率增加，不仅对人民的生命威胁越来越大，而且车辆在洪水灾害中也遭受巨大损失，滑移的车辆还可能带来次生灾害。本项目拟以城市洪水中行人和典型车辆为研究对象，采用力学理论分析与模型试验相结合的方法，研究城市洪水中行人和车辆的失稳机理。首先对收集的资料进行整理分析，确定研究对象，制定研究方案；其次提出洪水中行人与车辆的失稳模式，建立人车失稳及车辆滑移力学模型，导出起动流速公式和滑移速度公式；接着在水槽中开展一系列起动流速和水流作用下车辆滑移速度试验研究，利用试验数据率定相关参数，并对公式进行验证；最后运用验证过的公式对城市洪水中行人和车辆的失稳状态进行预测，绘制典型区域城市洪水中行人和汽车的危险等级分区图。研究成果能为制定城市洪水中人民避难转移方案及停车场的布置等提供重要依据，还可完善现有的洪灾风险评估方法。

由于全球气候条件的变化，极端天气频频出现，而世界城市化进程的加快，导致由暴雨引起的城市洪水灾害频繁发生。城市地区经济发达，人口密集，洪水灾害一旦发生，街道上的车辆及行人在洪水的作用下容易失去稳定，造成巨大的人身伤害和经济损失。因此，研究城市洪水灾害中车辆及行人的安全稳定性具有重要的现实意义。而制定具有现实指导意义的车辆及行人安全稳定的判别标准，对于城市防洪减灾工作意义重大。本课题首先分析了洪水中人体和车辆的受力特点及失稳机理，提出了拖曳力影响因素，结合失稳临界条件建立了相关方程，导出了跌倒失稳流速公式，接着在室内水槽中对四款3D建模打印的人体模型和汽车模型开展了一系列试验研究，并运用试验数据拟合了跌倒失稳流速公式参数，与前人研究成果对比表明：研究成果可以用于预测洪水中行人和车辆失稳；利用用不同人群的握力大小作为在洪水中抵抗能力的标准，引入人群分类因子Kr，给出了不同人群在洪水中跌倒失稳的判别标准。最后分析现行城市道路洪水交通安全的标准及其制定方法，在前面车辆及行人安全性研究的基础上，提出城市洪水灾害中的车辆及行人交通安全的新判别标准，建立城市洪水灾害中车辆及行人的三色预警机制。 课题执行期间，发表标注项目资助的文章5篇，培养本科生硕士生各3名，项目负责人参加国际会议1次，参加国内会议4次。