门窗破坏对低矮房屋风灾易损性的影响分析

发布时间：2018-06-04 23:41

本文选题：低矮房屋 + 开孔房屋　；参考：《西南交通大学》2017年硕士论文

【摘要】：大量的灾后调查表明:在强风中,低矮房屋通常是以围护结构破坏为主要破坏模式,当墙上或屋面出现损毁后,雨水渗透到房屋内部结构会导致更加严重的经济损失,甚至房屋倒塌而危害到人们的生命安全,这些破损甚至倒塌是导致风灾损失巨大的重要原因。此外,破损的围护结构构件以及建筑周围环境中的残骸,如玻璃、屋面板、石子、生活垃圾等残骸有可能成为飞掷物,从而威胁风向下游处建筑的围护结构安全。因此研究强风引起的低矮房屋的围护结构破坏以及飞掷物对围护结构的影响对于防灾减灾和风险控制有重要意义。本文的主要工作有以下几点:(1)介绍了房屋外门窗的飞掷物冲击破坏模型以及模型中各参数的意义和取值,分析了风速和门窗面积比对破坏概率的影响,该模型的破坏概率对风速非常敏感,在低风速下门窗面积比对破坏概率的影响不大,随风速增加,门窗面积比的对破坏概率的影响变大。(2)基于非定常伯努利方程推导了墙面存在单开孔和多开孔情况下的内压控制方程,根据开孔处的外压分别计算了迎风墙存在单开孔,双开孔和三开孔时的内压响应,发现单开孔时内压响应时程和外压几乎是一致的,内压的振幅略微大于外压的振幅,且可以从功率谱密度图看出有明显的共振峰;在双开孔时内压响应由两个开孔同时控制,但如果其中一个开孔较大则内压由该开孔处的外压主导,内压响应接近较大的开孔外压,如果两个开孔大小非常接近则内压接近两个外压的平均值;在三开孔时内压响应受多个开孔共同控制,内压跟三个开孔处的外压都有较高的相关性,从功率谱密度图未发现明显的共振。(3)外门窗在风压和飞掷物作用下发生破坏使房屋产生内压响应,从而屋面的抬升力在内压和屋面外压共同作用下增大,导致屋面板的失效概率增加。在风向垂直于门窗所在的墙面时屋面板的破坏概率最大,在风向平行于门窗所在墙面时屋面板的破坏概率最小。
[Abstract]:A large number of post - disaster investigations show that in strong winds, low houses are usually destroyed by the structure of the enclosure. When the walls or roofs are damaged, the infiltration of rainwater into the internal structure of the house will cause more serious economic losses, even the collapse of the house which endangers the safety of the people. These breakages and even the collapse are caused by the wind. In addition, the wreckage of damaged enclosure structures and the debris in the surrounding environment, such as glass, roof panel, stone, and living waste, may be a flying object that threatens the safety of the enclosure structure downstream of the wind. The impact of throwing objects on the enclosure structure is of great significance to disaster prevention and mitigation and risk control. The main work of this paper is as follows: (1) the impact damage model of the flying objects and the significance and value of the parameters in the model are introduced. The influence of wind speed and the area of door and window on the failure probability and the failure probability of the model are analyzed. It is very sensitive to wind speed. In low wind speed, the effect of window area ratio on failure probability is little, with the increase of wind speed and the effect of area ratio of doors and windows on failure probability. (2) based on the unsteady Bernoulli equation, the internal pressure control equation of wall face with single opening and multiple opening is deduced, and the windward wind is calculated according to the external pressure at the opening. The internal pressure response of the wall with single opening, double opening and three opening is found. It is found that the internal pressure response time and external pressure are almost identical in the single opening. The amplitude of internal pressure is slightly larger than the amplitude of external pressure, and the obvious resonance peak can be seen from the power spectral density diagram; the internal pressure response is controlled by two openings at the same time, but if one of them is in one of the open holes. The inner pressure is dominated by the external pressure at the opening, and the internal pressure response is close to the larger opening pressure. If the size of the two openings is very close, the internal pressure is close to the average of the two external pressures; the internal pressure response is controlled by multiple openings at three openings, and the internal pressure is closely related to the external pressure at the three openings, from the power spectrum density. No obvious resonance was found in the degree chart. (3) the failure of the outer doors and windows under the action of wind pressure and flying objects caused the internal pressure response to the house, thus increasing the internal pressure of the roof and the external pressure of the roof, which resulted in the increase of the failure probability of the roof panel. The failure probability of roof panels is parallel to that of windows and doors.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU746

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