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通过对成都宽窄巷子历史文化保护区部分房屋、门头结构的安全性鉴定、抗震鉴定及处理建议的介绍,总结了对该类老旧房屋、古建筑结构进行结构安全性鉴定及抗震性能鉴定的技术要点. 相似文献
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Experimental determination of the discharge flow coefficient at a doorway for fire induced flow in natural and mixed convection 下载免费PDF全文
The study is an experimental investigation of the discharge flow coefficient at a doorway‐type opening in the case of a fire in an enclosure open to atmosphere. Natural and mixed convection flows are considered with the use of mechanical ventilation. The discharge coefficient is defined as the ratio between the effective flow rate determined experimentally and a theoretical flow rate based on a Bernoulli approach. The effective mass flow rate is obtained from velocity field measured with stereoscopic particle image velocimetry technique. The theoretical flow rate is calculated from vertical temperature profiles measured from both sides of the doorway. Only inflow rate is considered for the calculation of the discharge coefficient. In natural convection mode, a CD value of 0.54 ± 0.5 is obtained on a reduced‐scale opening (to be compared with 0.68 at large scale). In a mixed convection case, the discharge coefficient is much lower and reaches 0.26 ± 0.06. This study shows that the discharge coefficient CD may vary significantly regarding the dimension of the opening and the flow conditions (natural and mixed convection). It illustrates the limits of considering a constant discharge coefficient when dealing with doorway flows in a confined and mechanically ventilated compartment. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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由于门洞型过水断面的水力计算涉及超越方程的求解问题,因而使目前的求解方法仅限于图表法或试算法,既不便于实际工作又很难保证成果精度。通过对原计算函数的优化拟合,提出了标准门洞型过水断面水力计算的简捷表达式,避免了目前常规方法获解所存在的问题,在实用范围内,成果的最大误差仅为0.48%。 相似文献
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针对目前图表法、试算法及近似法存在的问题,采用优化拟合的方法,以标准剩余差最小为目标函数,在工程适用参数范围内,经拟合分析及计算获得了表达形式更加简单直观、常数及系数项数字位数最少、便于记忆及实际应用、计算精度满足设计要求(最大误差为0.685%)的近似公式,具有一定的实用意义。 相似文献
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介绍了京沪高铁荆河特大桥现浇梁斜跨公路主干道门洞施工技术,重点阐述了地基处理、门洞支架布置以及门洞施工等结构理论计算和现场施工实践经验及措施等内容,为类似工程施工提供技术和经验支持。 相似文献
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The assessment of building thermal comfort quality in the Mediterranean context necessitates detailed information concerning
local air speed and temperature inside the space. We have extended the three-dimensional zonal model ZAER (Zonal AERial model)
to enable predictions of air flow pattern and thermal distributions between and within rooms. Numerical simulations from the
new program have been compared with data obtained from measurements on the experimental cell Minibat (CETHIL, INSA Lyon laboratory)
and with the prediction of another zonal model as well as a computational fluid dynamics (CFD) tool. The comparison indicates
that this new program is an effective model for predicting air flow and temperature distribution in a partitioned building.
By coupling ZAER with a thermal comfort model, we study the influence of a passive solar component belonging to a south-oriented
room upon the winter thermal comfort of an unconditioned Tunisian dwelling. The obtained results show that this simulation
tool has the potential to describe realistically the thermal comfort within a dwelling, and that a Trombe wall can be a useful
heating component to improve thermal winter comfort in the Tunisian context, even in another room. 相似文献
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结合青岛海湾大桥跨胶黄公路段工程,依据预留门洞满堂支架布置资料,以人行门洞为例,分析了满堂支架在施工过程中的受力情况.分别对支撑箱梁底板、腹板、翼缘板部分的满堂支架进行计算,确保满堂支架的稳定性,以保证施工过程的安全. 相似文献
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结合青岛海湾大桥跨胶黄公路段工程,依据预留门洞满堂支架布置资料,以人行门洞为例,分析了满堂支架在施工过程中的受力情况.分别对支撑箱梁底板、腹板、翼缘板部分的满堂支架进行计算,确保满堂支架的稳定性,以保证施工过程的安全. 相似文献
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