火灾情况下某单洞双层盾构隧道人员疏散分析

对于火灾情况下单洞双层超大断面双层盾构隧道人员疏散问题,在现有的规范中,没有相关条文说明给出明确要求。主要针对火灾情况下某单洞双层盾构隧道人员疏散进行分析,对我国某水下盾构隧道开展了火灾情况下人员疏散的模拟研究。利用Pathfinder模拟疏散软件,通过模拟计算获得该双层盾构隧道发生一起火灾情况下人员逃生所需的时间,验证其疏散通道的疏散能力,以及疏散楼梯尺寸、疏散逃生洞口间距的有效性。在模拟中,将火源设置在隧道的下层,人员从隧道下层往上层疏散。结果表明,基于隧道内疏散楼梯最大的有效宽度,当疏散逃生洞口间距设置为36m时,方可将人员疏散至未失火层隧道的时间控制在6 min以内,从而满足"6 min原则"要求。     

西部复杂性地貌地区消防规划评估与建设研究 ——以凉山州区域为例

城市消防规划作为城市消防安全体系建设的重要依据,是助力城市现代化进程、推动城市综合安全智慧网络形成的重要基石。通过对凉山州各地貌地区消防现状存在问题的分析,结合凉山州的实际情况及全州建设发展多种形式综合性消防应急救援队伍的需要,提出了能满足全州消防安全需求且能够有效指导城市消防建设的相应对策。     

Ecosystem restoration in fire-managed savanna woodlands: Effects on biodiversity,local livelihoods and fire intensity

Ethiopia aims to restore 15 million ha degraded forests and woodlands, but effects on the potentially contrasting goals of long-term carbon storage, biodiversity and sustainable livelihoods are unknown. To quantify the effects of grazing exclusion on vegetation and fire behaviour, we established six 30 × 30 m fenced exclosures with grazed controls, in a mesic wooded savanna. Experimental burns were done after 1.5 years. Tree seedlings were few but more common inside fences. Field layer cover and biomass increased inside fences, and grass species increased in numbers and cover. Fire intensity was higher inside fences, killing shrubs and saplings but not mature trees. Interviews confirmed that overgrazing has resulted in “cool fires”, causing shrub encroachment. High-intensity fires occurred in the 1980s after a zoonotic disease killed most livestock. Short-term increase in carbon storage through fire and grazing exclusion may lead to loss of pasture, and in the long-term increased wildfire risk.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01343-7) contains supplementary material, which is available to authorized users.     

加油站火灾爆炸故障树分析

采用安全系统工程的方法,对加油站的火灾爆炸事故进行了故障树分析。通过故障树分析,得出4个最小径集,指明了预防事故发生的可能途径;从而确定出加油站火灾爆炸事故的预防措施,并做出安全检查表,以供现场实施参考。     

Numerical simulation of small-scale pool fires of LNG

Liquefied natural gas (LNG) has been largely indicated as a promising alternative solution for the transportation and storage of natural gas. In the case of accidental release on the ground, a pool fire scenario may occur. Despite the relevance of this accident, due to its likelihood and potential to trigger domino effects, accurate analyses addressing the characterization of pool fires of LNG are still missing.In this work, the fire dynamic simulator (FDS) has been adopted for the evaluation of the effects of the released amount of fuel and its composition (methane, ethane, and propane), on the thermal and chemical properties of small-scale LNG pool fire. More specifically, the heat release rate, the burning rate, the flame height, and thermal radiation, at different initial conditions, have been evaluated for pool having diameter smaller than 10 m. Safety distances have been calculated for all the investigated conditions, as well.Results have also been compared with data and correlations retrieved from the current literature. The equation of Thomas seems to work properly for the definition of the height over diameter ratio of the LNG pool fire for all the mixture and the investigated diameters.The addition of ethane and propane significantly affects the obtained results, especially in terms of radiative thermal radiation peaks, thus indicating the inadequacy of the commonly adopted assumption of pure methane as single, surrogate species for the LNG mixture.     

地下岛式地铁站台火灾时全封闭屏蔽门开启模式研究

为研究4种屏蔽门开启模式下地下岛式站台火灾时排烟效果,本文采用大涡模拟进行计算,研究的开启模式包括开启两侧共4个端门、开启两侧首尾活动门及中间活动门和开启一侧所有活动门、开启两侧所有活动门。着重研究站台危险高度和楼扶梯口处烟气温度、CO浓度、可见度以及顶棚烟气温度。研究发现火灾发展阶段开启两侧屏蔽门首尾及中间活动门的排烟效果最好,火灾稳定阶段开启一侧所有活动门排烟效率较高,开启两侧所有活动门虽然能够加大烟气流出开口,但是排烟效果最差。     

化工火灾事故调查方法研究

为克服化工火灾调查中人为因素的影响,增强事故调查的科学性和准确性,在总结化工火灾现场特点的基础上,提出化工火灾事故调查时应遵循的假设推理法,通过证据收集、分析资料、建立假设、检验假设和选择假设,构建化工火灾事故调查的证据系统,包括实物证据,位置证据、文件证据和人证,从火灾动力学角度分析了火灾痕迹的影响因素。结果表明:假设推理法重视证据收集,综合使用归纳推理和演绎推理,有助于避免主观判断的影响;采用系统方法收集证据,扩大证据收集的范围,列举证据清单和优先考虑敏感性证据的方法有助于提高调查效率;火灾行为、材料的热响应和灭火行动对火灾痕迹的形成有直接影响,分析时应充分考虑,以免作出错误的判断。     

基于文献计量法的火灾灾害研究现状及展望

为了解火灾灾害研究领域的发展现状及未来趋势,基于多种可视化工具,对2014—2020年期间,火灾灾害领域内的发文态势、学术合作、学术热点、研究趋势等内容展开分析。研究结果表明：该时期内,火灾领域发文量呈持续上升趋势;我国科研活力及持续发展性均处于世界前沿地位,中国科学技术大学是全球发文量和合作活跃度较高的机构;载发文量排名前5的期刊研究方向和出刊数量整体呈现出一定差异性和波动性;研究热点涵盖基于无人飞行器的森林火灾(野火)侦测调查、基于火灾现场整体模型搭建的计算机模拟火灾事故技术与研究、火灾下建筑物构件的耐火及倒塌行为研究、池火燃烧特性试验及现象调查、火灾碎片实验与分析方法,研究内容总体呈现具体化、精细化;目前火灾领域研究的前沿方向为热释放速率研究、基于数值模拟的火灾事故研究、对点火器(源)的调查研究、基于数值模拟的火灾事故调查等;根据分析推测该领域未来的科研活跃度将继续上升。研究结果可为火灾灾害领域内相关学者把握学科现状,研讨未来发展提供参考依据。     

一起甲苯爆炸事故的调查与分析

分析了利用压缩空气压送甲苯混合物时发生爆炸事故的直接原因和间接原因,提出了相应的对策.     

桔柑隧道进口段塌方原因分析与处理措施

通过对桔柑隧道进口浅埋段塌方前掌子面的状态与前期施工工序的追溯,详细分析了隧道塌方前出现的各种征兆,并对其塌方机理进行了分析与计算,提出了较为有效的解决初喷混凝土在涌水量较大的情况下与岩壁的结合问题,以及如何选择隧道开挖方式、对大断面铁路隧道穿越浅埋段的处理方案,并最终成功穿越该段,为类似工程提供了借鉴。