共查询到20条相似文献,搜索用时 31 毫秒
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通过火灾蔓延分析找到危险建筑并相应地进行改造,对控制木结构建筑群火灾蔓延的风险具有重要意义。针对上述问题,该文以场-网数值模拟为基础建立了考虑多火灾场景的危险建筑的识别方法。首先结合有向图的基本原理,提出了邻接矩阵、蔓延矩阵的确定方法;在此基础上给出了节点的危险度、连通度、重要度、损失期望等评价指标的计算方法;依据上述指标,利用关键节点的搜索算法识别出危险建筑;进一步考虑对危险建筑进行防火改造,通过更新矩阵、再次评价的方法给出了防火改造的优先级。最后该文将该方法应用于云南省某杆栏式木结构民居建筑群的防火改造分析,结果表明:该方法能有效确定出建筑群中影响火灾蔓延的危险建筑及其改造优先级,并能结合损失期望及改造效果评价,确定出改造建筑的数量。采用上述方法,只需对少数危险建筑进行拆除或防火加强,便可大幅降低火灾蔓延的风险,显著减少引燃建筑的数量及火灾损失。 相似文献
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Yi-Feng Chao 《中国工程学刊》2016,39(5):606-614
This study proposes a new method for regional seismic damage assessment. Automatic modeling is applied to construct models of school buildings from a property database and component models. The capacity curves of school buildings are obtained through numerical simulation of nonlinear structure analysis instead of deriving the capacity curves by substituting parameters derived from a commonly adopted statistical regression approach into a formula. With professionally pre-set settings, detailed regional seismic damage assessment can be performed using a large number of numerical models generated in a short time. The accuracy and reliability of the proposed method is validated by comparing the base shear – roof displacement curve with data from experimental results and ETABS analysis conducted by the National Center for Research on Earthquake Engineering, as well as data obtained using existing damage assessment methods. Reconnaissance report data on school buildings affected in the Chi-Chi Earthquake is also used for further verification. The proposed regional seismic damage assessment method makes structural analysis on individual structures possible to provide a more accurate and detailed damage assessment. 相似文献
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超高层建筑一旦发生火灾,其后果往往比其他类型的建筑物要严重很多。火灾自动报警系统能防患于未然。火灾探测器是消防火灾自动报警系统中的"感觉器官",它的作用是监视环境中有没有火灾的发生。一旦有了火情,就将火灾,温度、烟雾、气体和辐射光强等物理量转换成电信号,并立即向火灾报警控制器发送报警信号。火灾探测器种类繁多,每种探测器的工作原理与使用范围都有所区别。论文针对超高层建筑的火灾特点,提出了该类型建筑内的火灾探测器设置建议。 相似文献
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This paper mainly discusses the features of China's architecture at historic sites with regard to fire protection, the causes of fire since 1949, reviewing their weaknesses in fire protection, and exploring modern technologies for fire prevention that are applicable to ancient buildings. We put forward suggestions to improve fire prevention and management: eliminating potential problems of fire, improving fire protection and establishing a better fire security system, which is especially important to protect ancient buildings. 相似文献
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我国火灾统计数据的聚类分析 总被引:1,自引:0,他引:1
采用聚类分析方法对我国大陆31个省、市、自治区火灾统计数据进行分析处理,对各地区的火灾损失进行了评价,并且用聚类和相关分析的方法讨论了经济发展水平、消防投入与地区火灾损失之间的关系。对6个方面的火灾损失数据进行无量纲处理,通过权重反映各属性对损失的总体贡献。用聚类的方法将31个地区火灾数据在整体上按火灾损失聚成了3类,每一类的内部火灾特性相对比较接近,不同类之间的差异较大。与火灾损失的聚类做相关性分析,发现地区火灾损失同生产总值、消防基本投入之间均为正相关,由此提出了一些火灾统计与管理的建议。 相似文献
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科学合理地考虑地震风险评估中各环节的不确定性是地震风险评估结果可靠的基础。该文利用某城市现有工程场地地震安全性评价数据,综合考虑城市地震危险性评估中的不确定性,以结构基本类作为城市建筑群模型,并考虑地震动不确定性对建筑群地震易损性的影响,建立了同时考虑地震危险性和地震易损性不确定性的地震风险评估模型,最终给出城市结构基本类不同极限破坏状态的年平均超越概率和50年内地震风险概率。基于结构不同极限破坏状态对应的损失比,获得每一种结构基本类的地震经济损失风险曲线。在此基础上,提出了采用地震风险一致概率为控制点,得到城市建筑群总的地震经济损失风险曲线组合的方法,该方法可为评估城市建筑群概率地震风险提供参考。 相似文献
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森林火险与气象因素的多元相关性及其分析 总被引:7,自引:0,他引:7
森林火灾发生概率预测涉及气象、树种、地理条件与人类活动等诸因素,气象参数对火灾的影响一直是森林火灾研究的重点之一。选用日平均湿度、降水量、平均风速、平均温度和日照时间等5种典型气象参数,利用BP神经网络分析了它们对火灾发生概率的综合影响;研究了多种气象参数综合作用下火灾发生概率的变化规律。结果表明,气象参数与火灾发生概率之间存在稳定的关联,神经网络在处理多参数综合影响方面具有较好的泛化能力,可以作为预测林火概率的可靠方法,为森林火灾研究提供了基础数据。 相似文献
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通过对某多金属矿山现场混制无梯重铵油炸药生产工艺运用道火灾化学评价法进行安全评估,得出其安全措施补偿前后的火灾爆炸指数和危险暴露面积、危害系数、危险等级、实际可能财产损失等指数。以数据说明了评估目标的基本安全性。同时,利用DOW指数法的完整体系,进行安全成本投入性价比和投入方案的线性规划分析,给出了安全资金投入建议。 相似文献
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为研究方钢管混凝土柱-外环板式组合梁节点在地震损伤后的耐火性能,该文建立了有限元数值模型,并用其他研究者完成的试验数据对模型进行了验证。在此基础上分别建立了震损后组合梁节点在三种受火工况下耐火极限计算模型,分析了组合梁节点柱防火保护层在滞回加载中的脱落位置及脱落程度和三种受火工况对节点耐火极限、破坏模态的影响。结果表明:经历柱端往复荷载作用的节点随着损伤程度的不断加重,钢管应力值及变形程度明显增大;当节点在楼板以下区域受火时,随着受火时间的增长,栓钉由底部至顶部的温度梯度较明显,楼板混凝土由于栓钉的影响,温度场分布呈现波浪形;不同损伤程度及不同受火工况对节点破坏模态均影响显著,但有无考虑防火保护层脱落的节点在三种受火工况下的破坏模态均没有较大差别;在楼板以下区域受火及楼板以上区域受火两种工况下,防火层脱落对重度损伤节点的耐火极限影响显著。在楼板上下区域均受火的工况下,防火层脱落对节点的耐火极限没有显著影响。 相似文献
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中国火灾与社会经济因素的关系 总被引:22,自引:2,他引:20
对中国的火灾统计数据与社会经济数据之间的关系进行了研究,发现中国火灾与社会经济因素的关系和国外相反:中国的火灾形势在经济越发达的地方越严重,并且随着经济的发展更趋严重。讨论了火灾与经济水平及教育水平的关系,提出了火灾和经济的更为全面的关系,即随着经济的发展,火灾形势是先严重后趋缓和。根据所讨论的结果对中国未来一段时期的火灾情况做出了一些预测。 相似文献
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The effect of localised fire damage on the tensile and compressive properties of fibre-reinforced polymer (FRP) composites is investigated. A simple model based on rule-of-mixtures is presented for determining reductions to the tensile stiffness, tensile strength, compressive stiffness and compressive strength of composite panels with localised fire damage of any shape and size. The validity of the model is rigorously tested against experimental tension and compression property data for a glass/polyester composite with localised fire damage in the shape of a circle, oval, square, diamond or in a irregular shape. The model is found to accurately predict the tension and compression properties of composites with localised fire damage of any shape, and is expected to be a useful model for estimating the residual structural integrity of fire-damaged composite panels. 相似文献
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为了给煤矿外因火灾危险等级评价提供一种更加合理的方法,采用将突变理论与模糊数学相结合的突变级数法,从明火致因、电火致因、其他原因等3个方面分析了煤矿外因火灾的影响因素,建立了煤矿外因火灾危险评价指标体系,并运用突变级数法对煤矿外因火灾危险等级进行评价。以沈阳焦煤集团林盛煤矿为例,基于突变级数法,求得该煤矿外因火灾危险等级评价的总突变隶属矩阵,依据总突变隶属函数值越大越优的原则,得到该煤矿外因火灾危险等级为二级,即较安全。依据评价结果,提出了提高该煤矿外因火灾安全性的相关对策。 相似文献
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Risk assessment and early warning systems for industrial facilities in seismic zones 总被引:1,自引:0,他引:1
Ernesto Salzano Anita Garcia Agreda Giovanni Fabbrocino 《Reliability Engineering & System Safety》2009,94(10):1577-1584
Industrial equipments and systems can suffer structural damage when hit by earthquakes, so that accidental scenarios as fire, explosion and dispersion of toxic substances can take place. As a result, overall damage to people, environment and properties increases. The present paper deals with seismic risk analysis of industrial facilities where atmospheric storage tanks (anchored or unanchored to ground), horizontal pressurised tanks, reactors and pumps are installed. Simplified procedures and methodologies based on historical database and literature data on natural-technological (Na-Tech) accidents for seismic risk assessment are discussed.Equipment-specific fragility curves have been thus derived depending on a single earthquake measure, peak ground acceleration (PGA). Fragility parameters have been then transformed to linear probit coefficients in order to obtain reliable threshold values for earthquake intensity measure, both for structural damage and loss of containment. These threshold values are of great interest when development of active and passive mitigation actions and systems, safety management, and the implementation of early warning system are concerned.The approach is general and can be implemented in any available code or procedure for risk assessment. Some results of seismic analysis of atmospheric storage tanks are also presented for validation. 相似文献
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J.H. Hunt 《International Journal of Refrigeration》1983,6(1):39-42
Over the last decade several large scale fires occured in New Zealand slaughter-houses. Some aspects of these fires are reported in detail, mainly the damage to frozen meat. The real fire situations confirm laboratory tests that frozen meat does not propagate fire spread horizontally, packaging materials permit the spread to a limited degree and frozen meat constitutes a low fire risk storage material. 相似文献