【作者】 肖春花；

【导师】 姚斌；

【作者基本信息】 中国科学技术大学 ， 安全技术及工程， 2011， 硕士

【摘要】 随着交通事业的不断发展,城市交通方式不断改善。为实现各种交通方式之间的衔接,满足旅客中转换乘的需要,综合交通枢纽已在各大城市相继出现。由于使用功能的需要,综合交通枢纽中的交通换乘大厅常设计为大空间结构。在实际工程中,该类大空间建筑区域超出了现行防火规范关于防火分区面积和疏散距离的要求,一般作为人员疏散的“准安全区”来设计。目前“准安全区”的设计与评估主要依靠消防性能化方法对具体的工程案例进行论证,尚未形成统一的设计准则。本文以建筑面积为10000m~2的换乘大厅规则立方体模型为研究对象,分别针对顶部开口和高侧窗开口两种自然排烟方式下的换乘大厅作为“准安全区”设计的准则进行研究,给出普遍适用的换乘大厅“准安全区”判定条件。对于采用顶部开口的综合交通枢纽换乘大厅,研究了换乘大厅的净空高度、顶部开口面积占地板面积的比例、相邻顶部开口之间的距离等因素对换乘大厅自然排烟效果的影响。分别设置模型净空高度为5m、6m、8m、9m、10m,顶部开口面积占地板面积的比例为2%、4%、6%、8%、10%、12%、14%、16%、18%、20%,相邻顶部开口中心之间的距离为10m、20m、30m、40m、50m、60m、70m几种工况,运用FDS软件对必要场景建立火灾模型并进行烟气模拟后,对30min内临界安全计算场景的影响参数进行分析,在结合三维曲面拟合的基础上得到采用顶部开口的综合交通枢纽换乘大厅作为人员疏散的“准安全区”设计的判定计算式。对于采用高侧窗开口的综合交通枢纽换乘大厅,研究了换乘大厅的净空高度、高侧窗的开口形式、开口有效面积占地板面积的比例以及高侧窗的开口高度对自然排烟效果的影响。在固定单个高侧窗开口面积为1m~2的基础上,分别选取净空高度为5m、6m、8m、9m、10m,高侧窗开口形式为两面对称开口、面积比例为2%,四面对称开口、面积比例为2%以及四面对称开口、面积比例为4%三种情况进行对比研究。此外,针对不同的净空高度设定对应的一系列高侧窗开口高度值,用以研究高侧窗开口高度对排烟效果的影响。结果表明,建筑的净空高度和高侧窗开口的面积比例对排烟效果影响较大;位于墙壁上边缘的开口相对于其它高度的开口具有明显的排烟优势;当高侧窗开口不沿墙壁上边缘布置时,最优开口高度约在净空高度的50%处,且该最优开口高度仅与净空高度有关,与开口形式和开口面积比例无关。采用高侧窗开口的换乘大厅用作人员疏散的“准安全区”设计需满足的条件为:当净空高度低于8m时,高侧窗开口面积占地板面积的比例不低于4%;净空高度大于8m时,高侧窗开口面积占地板面积的比例不低于2%,且当净空高度小于10m时,高侧窗应沿墙壁上缘连续布置。更多还原

【Abstract】 With the development of transport, urban transportation improves continuously. The integrated transport hub has emerged in the major cities one after another to meet the needs of convergence between the various transportation and transferring passengers. In the needs of utility, the transfer hall in integrated transport hub is often designed to large space structures. In the actual project, such large space structure position is usually designed as Quasi-Security Zone, because it beyond the requirements about areas of fire district and distance of fire safety evacuation provided in the existing norms. At present, the fire safety of Quasi-Security Zone is mainly demonstrated through performance-based fire prevention method but no more uniform design criteria.In this paper, cube model of transfer hall which area was 10,000 square meters was taken as the research object. Two ways of natural ventilations—top opening and high-side window opening was discussed respectively, generally applicable decision conditions of Quasi-Security Zone are presented.With regard to transfer hall using top opening in integrated transport hub, different headroom, different ratios accounted for floor area and different adjacent distances of natural ventilations was considered compositely to observe the effects of smoke exhaust. By choosing headroom as 5m, 6m, 8m, 9m, 10m, top opening ratio accounted for floor area as 2%,4%,6%,8%,10%,12%,14%,16%,18%,20%, and adjacent central distances of natural ventilations as 10m,20m,30m,40m,50m,60m and 70m, the necessary fire scene model was established and simulated by use of software FDS. Then within thirty minutes the parameters of critical security scene close to insecurity ones were analyzed. By taking advantage of three-dimensional surface fitting method, the determine equation designing transfer hall of integrated transport hub with top opening as Quasi-Security Zone was proposed.Towards transfer hall using high-side window opening in integrated transport hub, different headroom, different ratios accounted for floor area and different height of high-side window was considered. based on setting the area of a single high-side window to be one square meters, five headroom—5m, 6m, 8m, 9m, 10m, and three opening forms and area ratios of high-side window—opening area ratio of 2% on one group of opposite sides, opening area ratio of 2% on two groups of opposite sides and opening area ratio of 4% on two groups of opposite sides were selected to study comparatively. In addition, how opening height of high-side window affects the effects of smoke exhaust was researched through setting series of opening heights of high-side windows corresponding to different headroom. The results show that headroom of buildings and ratio accounted for floor area are the main effects on the smoke exhaust, high-side windows at the edge of the wall have obvious advantage on smoke exhaust compared to other opening height, when the high-side windows are not at the edge of the wall, the best opening height of high-side windows is at about 50% of headroom, and the best opening height is only related with headroom but the opening form and ratio accounted for floor area. If the transfer hall with high-side window openings is designed as Quasi-Security Zone, the high-side window opening area ratio accounted for floor area is not less than 4 percent when the headroom is lower than eight meters and 2 percent when higher than eight meters, and the high-side window should be continuous arranged at the edge of the wall when the headroom is lower than ten meters.更多还原