An Experimental Study of Ascent and Descent Movement of People on Long Stair with High Occupant Density

This paper presents an experimental study of the movements of both ascent and descent in a high occupant density 20-level building in order to exploit the characteristics of occupant movement on long stairwells. The movement processes of the participants are recorded in order to estimate both overall and local movement speeds, as well as flow rate and occupant density in the stairwell. When a merging flow is presented, the average movement time from one floor to the next is 35.8 s?±?15.6 s, and 37.3 s?±?10.6 s for ascent and descent movement, respectively. When a merging flow is not presented, the average movement time per floor is 15.1 s?±?0.8 s and 11.9 s?±?0.8 s for the ascent and descent movement. Under congested conditions, the average speeds on long stairwells maintains a relatively constant value of approximately 0.50 m/s?±?0.17 m/s, and 0.61 m/s?±?0.14 m/s for respective ascent and descent movement, while the traveling distance has no obvious impact on speed. Furthermore, the relationship between velocity and density in our observations is in line with linear functions and equations are accordingly proposed.     

Individual Stair Ascent and Descent Walk Speeds Measured in a Korean High-Rise Building

The purpose of this study was to collect and analyze individual unimpeded stair ascent and descent walk speeds for the Korean population. To collect these data, a full-scale experiment was conducted in a 50-storey residential building in Korea involving 30 male and 30 female participants with an average age of 23.4 years. Each participant was required to ascend 50 floors and after a suitable rest period was then required to descend 50 floors using the stairs. Arrival times on each floor were recorded using video cameras, allowing floor by floor walk speeds to be determined and to assess whether fatigue affected the descent/ascent. The average descent speed for the male and female population was 0.83 m/s and 0.74 m/s, respectively, while the average ascent speed was 0.66 m/s and 0.48 m/s. However, there was no significant relationship between body mass index and stair walk speed or unimpeded horizontal walk speed and stair walk speed. During the descent, 50% of the population displayed a decrease in the walk speed over the final half of the descent with a maximum decrease of some 19%. However, some 50% of the population increased their travel speed during the final half of the descent. During the ascent, all participants decreased their speed over the first 20 floors by an average of approximately 60%. Implications of these findings for evacuation modeling/simulation are discussed.     

Experimental Influence of Pedestrian Load on Individual and Group Evacuation Speed in Staircases

To obtain a relationship between evacuation speed and the load on pedestrians in fire cases, a series of individual and group evacuation experiments were conducted in load conditions of 0 kg, 5 kg, and 10 kg. In individual evacuation, the upward evacuation speed decreased as the floor increased while the downward evacuation speed changed very little with the floor. In group evacuation, the average group evacuation speed decreased as the pedestrian load increased. The group upward average evacuation speed was decreased by 25.7% as the load increased from 0 kg to 10 kg; the corresponding group downward average evacuation speed was decreased by 28.4% as the load increased from 0 kg to 10 kg.     

江阴大跨越输电塔模型试验研究

本文基于江阴大跨越输电塔模型试验工作 ,对试验模型设计与制作、加载及反力装置的设计、试验工况及测点布置等进行了研究。结合塔架模型试验和高强度螺栓受剪连接试验结果 ,验证了大跨越的设计是安全可靠的。文中还对塔架计算模型、杆件次应力、高强度螺栓群连接极限承载力等问题进行了讨论 ,并得出一些有益结论供工程设计参考。     

高层建筑电梯楼梯协同疏散的仿真实验研究

近年来高层建筑逐渐增多,但高层建筑普遍存在逃生线路长,火灾严重性大的问题。为了缩短高层建筑在消防疏散中的疏散时间,降低高层建筑火灾发生后的事故严重程度,利用疏散软件Pathfinder分析了高层建筑中使用电梯楼梯协同疏散的可行性。结果表明:高层建筑电梯可以作为协同疏散的辅助工具,增加一部电梯比单纯增加电梯最大运行速度要更加有效;设置每层电梯都使用总人数的固定比例进行疏散的时候,楼梯资源不易被充分利用;当设置n层及n层以上每层总人数的不同比例使用电梯进行向下疏散,存在最佳疏散楼层N11及最佳疏散比例20%,最后一个通过电梯疏散完毕与最后一个通过楼梯疏散完毕的人员仅相差2.7s,此方法可以为相关高层建筑火灾疏散策略的决策提供一定的参考依据。实验结果说明了电梯疏散的教育和培训很重要,在高层建筑中合理使用电梯进行疏散可以很大程度减少总疏散时长。     

混凝土导热系数试验与分析

为了研究基于现代施工工艺制成的混凝土导热系数,通过稳态平板导热仪对多种混凝土(包括普通混凝土、高强混凝土、再生混凝土以及配筋混凝土)试件进行了导热系数试验,考察了包括骨料体积分数、水灰比、骨料类型、外掺料掺量、温度、干湿状态及钢筋体积分数等因素对混凝土导热系数的影响;进一步考察了再生粗骨料取代率对再生混凝土导热系数的影响.通过这些因素的显著性分析,得到了各因素对混凝土导热系数影响的显著性大小依次为:干湿状态、再生粗骨料取代率、温度、骨料体积分数、骨料类型、钢筋体积分数、水灰比、掺和料种类.     

楼梯设计方法初探

在当代建筑中,楼梯已经转变为一个活跃的极具表现力的积极要素.然而,仍有相当数量建筑作品中的楼梯不合时宜,本文试图总结出楼梯的设计方法,以提高其在建筑创作实践中的可操作性和创造性. ……     

Experimental Investigation of the Effect of Fire Protection Lobby on Stair Pressurization System in a High-Rise Building

In this study, the stair pressurization system in a 40-storey high office building in Istanbul is investigated through field tests, in order to understand the effect of the presence of a non-pressurized vestibule (fire protection lobby, FPL) before entering the stair at each floor. The building without FPL is simulated by keeping only one of the two doors (of the stair and FPL) open at each floor. This method gave an opportunity to fix other parameters affecting the stair pressurization system and check solely the effect of FPL. Two different cases are taken into account, where the first one (all doors closed) analyses the condition that all stair doors are kept closed and the second one (critical doors are open) is conducted when the stairwell is opened to the floor on a given level (fire floor) and the stair termination door at the discharge floor is kept open. For both cases, the availability of the FPL is investigated by using the aforementioned arrangement. Under the conditions with approximately the same pressurized air flow rate at all doors closed condition, it is found that the availability of FPL increases the pressure difference between the stairwell and the corridor by a factor of approximately 2.2. This is also justified by using empirical formulations available in literature, where this ratio is calculated as 2.0. The results of this study showed that the FPL arrangement improves the effectiveness of pressurization system in a very high-rise building, despite some tolerable drawbacks.     

体外CFRP筋预应力混凝土箱梁长期受力性能试验研究

碳纤维（CFRP）筋具有优异的物理力学性能,可用于替代传统的预应力钢筋。制作了体外配置碳纤维筋预应力混凝土箱梁模型,对持续均布荷载作用箱梁的截面应力重分布、长期挠曲变形及裂缝发展等规、律进行了1001d的试验观测。基于素混凝土柱体的实测徐变系数,运用双线性法和曲率法分别对试验箱梁的长期挠曲变形进行预测。试验结果表明：受压钢筋应变较初值增长225％～268％,受拉钢筋的应变较初值增长36．2～38．6％,混凝土表面压应变较初值增长164％～224％。按现行设计规范计算长期荷载作用特征裂缝宽度较实测值偏小11．8％～55．5％。跨中长期挠曲变形实测值为初始变形的2．32～2．42倍,较现行设计规范取值偏大18．5％。     

压裂返排液生物处理实验研究

从油田压裂返排液中筛选出EB系列菌种,可高效降解压裂返排液中的高分子和有机污染物.考察了振荡时间、温度、接种量、菌种混合比例等对压裂返排液COD去除率的影响.结果表明:48 h振荡、25℃、10％接种量、菌种EB1和EB2按1∶1比例混合是较佳应用条件.EB复合菌种的应用范围较广,其pH值适用范围为6～9,矿化度适用范围为3000～20000 mg/L.该研究提高了压裂返排液生物处理技术规模化应用的可行性.     

配筋混凝土干燥收缩变形的试验研究

从宏观的应用角度出发,结合工程对配筋混凝土的干缩变形进行了深入的试验和理论分析.对40个配筋混凝土构件的约束干燥收缩变形从数据采集到试验结果进行了为期360天龄期的分析研究,在混凝土自由干燥收缩估算公式的基础上,考虑了钢筋及混凝土徐变综合的影响,提出了配筋混凝土干燥收缩应变多系数估算公式,公式的计算结果与186组试验数据符合良好.公式的提出是对以往收缩公式的改进和发展,并具有较好的工程适用性,为今后修订《混凝土结构设计规范》（GB50010-2002）中有关耐久性的条目提供了重要的试验数据和背景材料.     

Experimental Study on Descent Speed on Stairs of Individuals and Small Groups Under Different Visibility Conditions

Staircases play an essential role in multi-story buildings during emergencies, such as fire. Fires and the resulting smoke cause low visibility, which could affect the movement speed of the occupants. This must be taken into consideration during evacuation experimental design. This paper aims to study the stairwell evacuation performance of individuals and small groups under normal and impaired visibility conditions. The evacuation experiment was conducted in a five-story office building, with 75 subjects. The descent speed, the evacuation behavior, and the characteristic of small groups were analyzed and discussed. The descent speed of individuals decreased sharply when the visibility was reduced. The descent speed of small groups showed a relatively small downward trend. Group behavior had a negative effect on the evacuation performance during normal visibility. The group speed converged to the speed of the slowest group member. The group behavior contributed to a quicker movement speed in the low visibility condition. This was due to the stress of occupants being relieved. The group speed tended to be as fast as the fastest member of the group.     

高风速下线板式静电集尘器提效试验研究

为解决室内线板式静电集尘器在高风速条件下效率偏低的问题,设计制作了双区分体式静电集尘器样机,并通过测试该样机在不同条件下的PM2.5一次性过滤效率,考察了影响线板式静电集尘器高风速下性能的关键因素。结果表明,增加电离区"有效电流",减小集尘区极片间距,增加集尘区厚度是提高线板式静电集尘器高风速下性能的有效手段。依据试验结果对现有集尘器产品的电离区与集尘区进行优化改进并测试其在不同风速下的PM2.5一次性过滤效率表现。优化后的集尘器整体效率提升明显。     

对部分填充钢筋混凝土框架的试验研究

通过在合适的地方填充钢筋混凝土是一种很常用的加固方法。有时考虑到建筑上的需要,在加固中会将窗户或者门的开口留出来。但是目前我们对在水平循环荷载作用下的部分填充钢筋混凝土结构的行为还不十分了解。本研究旨在探究水平循环荷载下,通过部分填充而加固的柔性钢筋混凝土结构的性能。试验对象为9个三分之一比例的单层单开间模型,对其施加反复荷载。填充墙的纵横比(lw/hw,长度/高度)和安放的位置是试验中需要考虑的两个参数。试验结果指出,与无填充墙的结构相比,部分填充的RC结构显示出了明显更高的最终强度和更高的初始刚度。当填充墙的纵横比增大,结构的抗侧强度和刚度也有显著增加。此外,从试验中还可以看到,结构和填充墙之间的连接同样会影响填充结构的性能,那些同时连接到柱子和梁的部分填充墙模型显示出了最优的性能。     

十字形钢管混凝土中长柱轴压性能试验研究

为了研究不同试件肢长和钢管壁厚对十字形钢管混凝土中长柱轴压性能的影响,对9根十字形钢管混凝土中长柱进行了轴压试验.研究了试件的破坏全过程、荷载-位移曲线、应力-应变曲线和极限承载力.试验结果表明:试件主要为局部鼓曲破坏和弯曲失稳破坏;壁厚每增大1 mm,承载力平均提高23.6％,延性平均提高45.9％;试件肢长每增大2...     

长短板方案加固吹填淤泥土体的试验研究

在常规浅层真空预压地基处理的基础上,提出了一种改进的长短板方案,通过与常规方案在地表沉降、孔隙水压力消散情况、卸载后原位十字板剪切试验、钻孔取土及室内常规试验等方面进行了对比,发现其加固效果明显优于常规方案,并很好地缓解了土柱现象,土体加固效果较均匀。     

H形钢部分包裹混凝土组合中长柱轴心受压承载力试验研究

为了研究H形钢部分包裹混凝土(PEC)组合中长柱的极限承载力,用Q235B和Q345两种钢材制作12个PEC中长柱,对其进行轴心受压承载力试验,试验主要考虑含钢率、混凝土强度等因素。研究分析了焊接H形钢部分包裹混凝土组合中长柱的轴心受压极限承载力、荷载-位移曲线,对试件的承载力和稳定系数进行了理论和试验结果的对比。结果表明:焊接H形钢部分包裹混凝土组合中长柱的破坏模式有混凝土被压碎、柱整体弯曲、柱翼缘局部屈曲;在试验长度范围内,PEC柱承载力的影响因素主要有含钢率和混凝土强度等级,含钢率越大承载力越高,高强度混凝土可以大幅提高PEC柱的承载力;按照叠加原理公式计算的PEC柱承载力基本都低于试验极限承载力,试验得到的整体稳定系数都高于按《钢结构设计标准》(GB 50017—2017)得到的稳定系数,偏于安全;高强度钢和低强度等级混凝土不能很好地发挥协同作用,低强度等级混凝土只起到填充作用,强度发挥很小。     

低渗透油田压裂废水处理技术实验研究

通过低渗透油田压裂废水处理系列实验,研究了降黏预处理-Fe/C微电解-絮凝处理技术,有效地降低了废水的COD,考察H2O2、pH、Fe/C比例、Fe/C加量、Ca（OH）2加量及反应时间等影响因素。结果表明此实验的优化工艺条件为：H2O2加量0.5%、pH为1、Fe/C比例1∶1、Fe/C加量5g/L、Ca（OH）2加量3g/L、反应时间120min。     

油田压裂废液处理及回注实验

油田压裂废液具有高COD、高悬浮物等特点,处理达标难度大。以悬浮固体含量、悬浮固体颗粒粒径中值和含油量为指标,实验研究了混凝、微滤膜过滤技术参数,最佳条件为:絮凝剂投加量800～1 000mg/L,助凝剂投加量9～10mg/L,快速搅拌G值250～300s--1,慢速搅拌G值约50s--1,经50、10μm两级微滤膜过滤后悬浮固体含量、粒径中值、含油量满足SY/T 5329-2012《碎屑岩油藏注水水质指标及分析方法》标准要求。该方法工艺简单,成本低,在一定程度上解决了压裂废液难处理的问题。     

水下不分散混凝土外加剂应用试验研究

本文针对南平闽江大桥水下不分散混凝土力学性能进行了试验研究,对配合比进行了设计调整,检测TW—NA外加剂对水下浇注混凝土的抗分散性、流动性、自密实度及力学性能的影响,研究应用结果表明,TW—NA水下不分散混凝土外加剂的作用效果明显,制备的水下不分散混凝土的各项指标稳定。