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上海地铁站内行人楼梯交通特性 总被引：2，自引：0，他引：2
为对地铁站内行人楼梯进行规划、设计和管理,对上海地铁站内行人楼梯的交通特性进行分析.通过现场观测和摄像调查获取大量数据,利用统计学的方法分析性别、年龄以及信息对楼梯速度的影响规律;根据行人速度随密度变化的大致规律,对给定密度下的行人速度或者流量数据进行合并处理;适当加密变化敏感区域的数据,并利用这些统计数据建立上下楼梯行人的流量一行人密度一速度曲线关系.结果表明性别对行人速度没有显著影响,而年龄和信息对行人速度具有显著影响;从流量-行人密度-速度曲线看,行人在坡度为26°的楼梯的上下楼梯通行能力没有差别,约为88人/(m·min),对应的行人所占面积为0.20～0.22 m2/人.该结果可用于楼梯设施的规划和设计以及行人微观疏散仿真. 相似文献
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Time-to-cracking of the concrete cover induced by the steel corrosion is one of the critical problems faced by engineers, operators and asset managers in making strategies for the maintenance and repairs of reinforced concrete (RC)structures affected by corrosion. In this paper, a theoretical model for predicting the time-to-cracking is derived by assuming the bond between the steel bar and the concrete as a linear combination of perfectly smooth and bonded. The model takes into account the characteristics of existing exiguous flaws and initial cracks in the concrete before the load acting on RC structures. The validity of the proposed model is preliminarily verified by comparing the obtained results with the available experimental results. A remarkable advantage of the proposed method is its application to the prediction of the service life of RC structures, made of the deformed steel bars as well as the round bars. By determining an experimental constant α, which is related to the interface bond state between the steel bar and the concrete, the service life of RC structures can be predicted using the proposed scheme. Analysis of major factors affecting the time-to-cracking demonstrates that the length of the initial crack affects the service life of RC structures significantly. Moreover, the larger cover thickness and the smaller diameter of the steel bar within a certain range are beneficial to prolonging the time-to-cracking. 相似文献
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