坡地高层建筑非稳态雷暴冲击风荷载特性研究

发布时间：2019-01-03 15:03

【摘要】：目前结构风工程对于雷暴冲击风风荷载的研究多局限于稳态冲击射流模型,较少考虑风速随时间的变化以及坡地地形等因素的影响.基于冲击射流模型,引入衰减函数使得射流的入口风速更加接近真实的雷暴冲击风整个生命周期的衰变过程,并通过瞬态大涡模拟(LES)分析了坡地地形中坡顶位置处典型高层建筑的建筑风荷载特性及坡地地形雷暴冲击风场特性.结果表明,LES瞬态模拟具有较高的可靠性,非稳态冲击风场的风速波动较大,变化规律与实测的下击暴流风速曲线类似;建筑表面的风荷载具有强烈的非平稳特性,且随着风速迅速衰减;非稳态冲击风的风荷载波动大且潜在破坏能力更强;坡地地形下建筑迎风面风荷载普遍比平地小,且对建筑中上部的影响明显要大于底部,随着起坡角度的增大,建筑中上部风荷载逐渐减小.
[Abstract]:At present, the research on thunderstorm impingement wind load in structural wind engineering is limited to the steady impinging jet model, and the influence of wind speed with time and slope topography is seldom taken into account. Based on the impinging jet model, the attenuation function is introduced to make the inlet wind speed of the jet closer to the decay process of the whole life cycle of the real thunderstorm impact wind. The wind load characteristics of typical high-rise buildings at the top of slope terrain and the impact wind field characteristics of thunderstorm in slope terrain are analyzed by transient large eddy simulation (LES). The results show that the transient simulation of LES has high reliability, and the wind speed fluctuates greatly in the unsteady impact wind field, and the variation law is similar to the measured downburst wind speed curve. The wind load on the surface of the building has a strong non-stationary characteristic and decreases rapidly with the wind speed, and the wind load of the unsteady impact wind fluctuates greatly and the potential damage ability is stronger. The upwind load on the upper part of the building is generally smaller than that on the flat land, and the influence on the upper part of the building is obviously greater than that on the bottom. With the increase of the slope angle, the wind load on the upper part of the building decreases gradually.
【作者单位】：重庆大学土木工程学院;重庆大学山地城镇建设与新技术教育部重点实验室;
【基金】：国家自然科学基金资助项目(51208537)~~
【分类号】：TU973.213

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