共查询到18条相似文献,搜索用时 93 毫秒
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将公路安全性评价的理念应用到立交方案设计中,并结合广清立交工程设计实例,从立交型式、匝道与主线速度协调性、匝道出入口设计、地面交通组织等方面分析探讨了城市枢纽性立交在方案设计中必须考虑的公路安全性问题. 相似文献
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结合山东省高速公路,对高速公路立交匝道区的绿化和经济进行研究分析,系统分析研究高速公路立交匝道区内的土地利用状况、植物绿化品种及方式、经济开发特点等. 相似文献
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根据西宁火车站综合改造片区路网工程设计,为保证施工安全并考虑降低成本等因素,对互通立交A匝道现浇箱梁采取了WJΦ48mm×3.5mm碗扣式钢管满堂支架。本文详细介绍了现浇混凝土箱梁碗口支架体系的设计方案和验算步骤,可供工程技术人员借鉴。 相似文献
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受交通量的发展和路网新布局的形成等因素影响,已建的许多互通式立交面临改扩建。文章以重庆江津西彭互通式立交在原有A型单喇叭三路互通立交基础上改建成四路立交的工程为例,阐述了改扩建立交在选型和设计过程中的思路,总结了一些改扩建立交方案选择的原则,供同行参考。 相似文献
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文章以南宁市白沙-友谊大道互通式立交为研究对象,介绍了其工程概况与地形地貌,并对其交通量进行预测分析,同时结合其立交功能定位阐述了该立交方案的选型设计思路,通过对互通式立交型式进行综合比选,推荐出了功能完善、造价低的互通方案,可为城市道路立交工程设计提供参考和借鉴。 相似文献
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In this paper, ramp systems on the Beijing 3rd ring road are described as double-cell ramp systems with a bottleneck. By analyzing empirical data for the Beijing 3rd ring road, we found that the initial states have an important impact on the final convergence states of the ramp systems. Then, we studied the dynamic process of the ramp systems, determined the congestion mechanism, and then designed a ramp control method based on the obtained mechanism. Under a feasible demand, double-cell ramp systems exhibit two typical cases, including an upstream-bottleneck system (in which the bottleneck cell is upstream) and a downstream-bottleneck system (in which the bottleneck cell is downstream). Then, a cell transmission model is used to analyze the dynamic evolution processes, starting from different initial states, and determine the congestion mechanism for each case. It is proven that the two systems have different possible equilibrium sets and congestion mechanisms. In an upstream-bottleneck system, the downstream always converges to the uncongested equilibrium, while the upstream bottleneck cell may experience congestion under certain initial states. In a downstream-bottleneck system, the congestion starts downstream, and then gradually propagates upstream. Furthermore, based on the different congestion mechanisms, two demand adjustment strategies are proposed, which redistribute the stationary feasible demand. The simulation results indicate that both systems can converge to uncongested equilibriums after demand adjustment. The ramp demand adjustment methods provide a scientific basis for urban traffic system management. 相似文献
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多路互通式立体交叉的产生有其必然条件,文章在总结三路和四路立交形式的基础上,提出了五路和六路立体交叉的几种可能形式,并重点讨论了多路互通式立交布设时如何选择主线跨越方式、立交出口形式和左转匝道的类型。 相似文献
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文章以重庆绕城高速公路上的走马互通式立交为例,分析了群体优化思路在城市立交群规划布局和方案选择中的应用,总结了城市路网节点处互通式立交选型的一些经验,供同类工程参考。 相似文献
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We propose a fuzzy logic control for the integrated signal operation of a diamond interchange and its ramp meter, to improve traffic flows on surface streets and motorway. This fuzzy logic diamond interchange (FLDI) comprises of three modules: fuzzy phase timing (FPT) module that controls the green time extension of the current phase, phase logic selection (PLS) module that decides the next phase based on the pre‐defined phase sequence or phase logic and, fuzzy ramp‐metering (FRM) module that determines the cycle time of the ramp meter based on current traffic volumes and conditions of the surface streets and the motorways. The FLDI is implemented in Advanced Interactive Microscopic Simulator for Urban and Non‐Urban Network Version 6 (AIMSUN 6), and compared with the traffic actuated signal control. Simulation results show that the FLDI outperforms the traffic‐actuated models with lower system total travel time, average delay, and improvements in downstream average speed and average delay. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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通过安装车载测试系统收集香港港岛山区路段正常行驶工况下尾气中的CO、NOx、HC等污染物和油耗并辅助计算机软件进行分析。研究得出,山区道路设计、地形地貌和驾驶习惯对车辆油耗以及CO、NOx和HC排放有直接关系。可以通过坡道加宽、坡道延长、减少坡道红绿灯等措施减少车辆在山区道路行驶过程中速度变化频率,从而减少油耗以及CO、NOx和HC排放。 相似文献