An experimental study on fire characteristics of urban complex underground space based on BIM

Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space areas and densely populated.Once a fire occurs in the complex underground space,it will cause huge property losses and casualties.In order to reduce the risk of fire,it is necessary to deeply understand the development rules and characteristics of fire in the complex underground space of the city.This article has mainly carried on the following work:(I)A particularly complex model of the multi‐storey subway station was built.On this basis,three groups of comparative experiments were conducted to study the effects of fire power,fire location and smoke control system on fire development,and the conclusion that fire location is the most important factor for fire development was obtained;(II)In order to explore the entire space fire and the local space fire,CFD(Computational Fluid Dynamics)is used to build a large‐size fire model and a small‐size fire model respectively;(III)Multiple detector data as temperature slices were built,and it is expected to make full use of the simulation data to deduce the important index of fire location in the early stage of fire.All of the works in this paper will provide reference experimental data for the prevention and firefighting of a sudden fire in the complex underground space.

“Place Making”in Urban Complex Design: A Case Study of Tianfu Pearl Design Scheme

This paper introduced basic situation and challenges of Block 9, Dongdajie, Chengdu City, expounded basic definition and design concept of "place making", briefed the design scheme from three aspects, namely planning layout, space environment and architectural style, and concluded the application of the idea of "place making" in Block 9 design scheme in view of the multi-functional urban complex with high plot ratio.

Coherent Urban Complexity: The Issue of Architectural Control, the Case of Bole-Medhanialem Commercial Corridor, Addis Ababa, Ethiopia

The city of Addis Ababa,the capital of Ethiopia is experiencing tremendous changes,spatial as well as social and economic.The urban transformation of the city has shifted towards fragmented urban fabrics which fall short of coherent integration and enclosure of urban spaces for social interaction.This research evaluates recent commercial corridors of the city with regard to currently employed design regulations and guidelines.The paper reports findings of a site investigation,describes the emerging urban characteristics of Addis Ababa and the factors leading up to such urban form.The paper emphasizes on the importance of employing architectural limits on local design standards as they offer potential to achieve a coherent urban"whole".

Research and Practice of Meta-synthesis Management for the Government-led Urban Complex Construction Project

This paper researches the overall construction target of government-led urban complex construction projects based on the perspective of sustainable urban development. In order to achieve benefit maximization, the meta-synthesis management for the government-led urban complex construction project is studied. In order to combine theory and practice, several typical government-led urban complex construction project cases, such as Guangzhou Higher Education Mega Center and Guangzhou International Financial City etc. are examined. These examples point to the feasibility of government-led meta-synthesis management and demonstrate the benefits that can be achieved through this model.

The Settlement Characteristic of Underground Urban Complex in Shanghai

The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex which was located in Shanghai. The effects on water pressure and building settlements were analyzed as well. The numerical analyses by finite element method (FEM) were conducted. It showed that the soil under the excavation base continued to heave during the following certain construction stage. It also found that the bearing capacity of uplift piles which supported the buildings affected the structure quality significantly. The conclusions can be applied in future projects.

Discussion on Development Mode of Large Railway Hubs in High-speed Rail Era:From Transportation Complex to Urban Complex

At present, most of China's railway hubs are developed to be transportation complexes, with some problems like unsmooth traffic circulation, mixed but disordered functions, separated spaces, etc. In high-speed rail era, high-speed railway hubs should be regarded as the catalyst to promoted urban development. The mode of urban complex should be developed, to closely connect the railway hub and the surrounding area within walking distance, so as people could get to their destinations in the most convenient way. Furthermore, it would strengthen people's aggregation, thus to bring about larger scale urban development by the successful development of urban complex.

Landscape Design of Urban Rail Transit Complex Based on the Concept of Sustainable Development

On the basis of current development of urban rail transit complex in China,this paper proposed that it is necessary to build a complete landscape design system of urban traffic complex.Combined with the concept of sustainable urban landscape design,this paper explored landscape design of urban rail transit complex from the macroscopic,mesocopic and microscopic perspective,and analyzed many design cases to provide references for the sustainable landscape design of urban rail transit complex in China.

统筹式城市更新:中国城市更新的发展困境与优化路径

城市是一个生命有机体,需要不断更新来增强城市活力,促进城市现代化。城市更新的本质是城市空间的再造与治理优化。城市更新动因复杂多元,城市更新经济论、城市更新社会论、城市更新生态论、城市更新治理论、城市更新人本论和城市有机更新理论反映了各自特定价值追求及其偏好,共同指导城市更新实践。文章系统反思了中国城市更新在更新价值、更新内涵、更新主体、更新制度和运作机制等方面存在的发展困境,并提出以统筹式城市更新模式促进中国城市更新的可持续发展与有效治理。统筹式城市更新可从树立以人民为中心的城市更新理念、构建内涵式的包容性城市更新模式、完善联动协同的城市更新制度体系、建立因地制宜的城市更新运作机制、建设技术驱动的未来城市与智慧社区等方面系统推进。统筹式城市更新强调目标、主体、资源、技术、方式和效益等方面的统筹协调、系统高效和有机发展,追求城市发展与治理的深度融合,促进城市更新的可持续发展和整体性治理、国家空间布局优化与城市治理现代化。

机电顾问视角下城市综合体电气设计的思考

结合杭州某一城市综合体项目,分析了城市综合体建筑的电气设计的重点、难点及关键技术,归纳不同餐饮形态的负荷指标,并总结出经验取值范围;提出商业综合体的两种高压供电形式,并给出了不同选用原则;总结了酒店柴油发电机的设置原则;结合以往工作经验,提供了大型设备运输方案。

生产性服务业与制造业协同集聚对城市创新的影响研究

强化国家战略科技力量,提升国家创新体系整体效能是当今中国加快进入创新型国家前列的重要命题。在构建城市创新质量新指标的基础上,运用空间误差模型和空间滞后模型就生产性服务业与制造业协同集聚对城市创新的影响机制进行深入剖析。研究结果显示:生产性服务业与制造业协同集聚能提升城市创新质量,并能通过推进产业结构高级化、提升城市科技投入水平和吸引研发人员流入三个渠道促进城市创新质量的提升,协同集聚对东部和中部地区城市创新质量有促进作用,高端生产性服务业和低端生产性服务业与制造业协同集聚均能促进城市创新质量提升。此外,生产性服务业与制造业协同集聚能够推动新企业注册量的递增,进而提升城市的创业积极性与创业活跃度。生产性服务业与制造业协同集聚具有促进城市创新质量和创业活力两大功能,可以成为推动城市高质量增长和提升城市竞争力的重要工具。

2022年8月四川盆地持续性极端高温特征及不同模式预报误差分析

本文基于2022年8月四川盆地104站逐时温度、降水数据和1971—2021年历史同期数据,及EC、CMA-GFS、CMA-MESO模式的2 m气温预报等数据,运用统计学相关方法分析了此次极端高温过程的特征及预报误差。结果表明:①2022年8月四川盆地极端高温过程范围大、强度强、持续时间长,有87.5%站最高气温超过该站历史同期极值,且高温最强盛时段较历史同期明显推后。②2022年8月最高气温分布为东高西低,最高气温与历史同期极值差分布则相反,其中最高气温随站点海拔增大而减小,而极值差则随站点海拔先增大再减小。另外,受热岛效应影响,极值差大值站点主要集中在龙泉山脉附近。③高温期间,最高、最低气温平均值高、距平大,且累计降水量和雨日数也明显低于历史同期。④相较而言,EC模式的预报优势主要在盆地低海拔地区。而CMA-MESO模式在盆地周边陡峭地形区域的平均绝对误差则更小。另外,EC模式预报的最高气温峰值出现时间更接近于实况,而CMA-MESO模式预报高温持续日数更接近实况。

复杂场景下自适应注意力机制融合实时语义分割

实现高准确度和低计算负担是卷积神经网络(CNN)实时语义分割面临的严峻挑战。针对复杂城市街道场景目标种类众多、光照变化大等特点,该文设计了一种高效的实时语义分割自适应注意力机制融合网络(AAFNet)分别提取图像空间细节和语义信息,再经过特征融合网络(FFN)获得准确语义图像。AAFNet采用扩展的深度可分离卷积(DDW)可增大语义特征提取感受野,提出自适应平均池化(Avp)和自适应最大池化(Amp)构成自适应注意力机制融合模块(AAFM),可细化目标边缘分割效果并降低小目标的漏分率。最后在复杂城市街道场景Cityscapes和CamVid数据集上分别进行了语义分割实验,所设计的AAFNet以32帧/s(Cityscapes)和52帧/s(CamVid)的推理速度获得73.0%和69.8%的平均分割精度(mIoU),且与扩展的空间注意力网络(DSANet)、多尺度上下文融合网络(MSCFNet)以及轻量级双边非对称残差网络(LBARNet)相比,AAFNet平均分割精度最高。

Coordinated chaos control of urban expressway based on synchronization of complex networks

We investigate the problem of coordinated chaos control on an urban expressway based on pinning synchronization of complex networks. A node coupling model of an urban expressway based on complex networks has been established using the cell transmission model（CTM）. The pinning controller corresponding to multi-ramp coordinated controller was designed by using the delayed feedback control（DFC） method, whose objective is to realize periodical orbits from chaotic states. The concrete pinning control nodes corresponding to the subsystems of regulating the inflows from the on-ramps to the mainline were obtained and the parameters of the controller were optimized by using the stability theory of complex networks to ensure the network synchronization. The validity of the proposed coordinated chaos control method was proven via the simulation experiment. The results of the examples indicated that the order motion on urban expressway can be realized, the wide-moving traffic jam can be suppressed, and the operating efficiency is superior to that of the traditional control methods.

考虑互补效应的城市群多模式客运网络鲁棒性

为了分析城市群客运网络对突发事件的应对能力,从多种交通模式互补视角,基于复杂网络理论构建城市群多模式客运网络模型,应用引力模型建立节点失效后网络性能计算的规则,对城市群多模式客运网络的鲁棒性进行测度.引入基于鲁棒性的动态互补强度指标,对客运网络间的互补效应(CE)进行量化.对是否考虑CE时的鲁棒性进行对比,分析CE对鲁棒性的提升程度.以关中平原城市群为例进行实例研究,结果表明,在城市群多模式客运网络中,普铁网应对突发事件时的鲁棒性最强,公路网最弱.无论在何种攻击策略下,考虑CE时,城市群多模式客运网络的鲁棒性均有明显的提升,高铁网、普铁网和公路网的敏感度分别下降了19.1%、29.3%和22.0%.

城市防疫医疗救援网络的抗毁性与鲁棒性

为研究城市防疫医疗救援系统空间布局的合理性和防灾韧性,采用复杂网络技术构建了某城市防疫医疗救援网络模型,对其网络拓扑结构和网络特征基本参数进行分析,研究不同攻击模型下以边和点连通度为度量指标的结构抗毁性能力;通过设定不同的网络冗余与网络负荷,研究网络针对确定性攻击与随机性攻击的鲁棒性特征。研究结果可为城市防疫医疗救援系统的空间优化布局和核心场所强化建设提供理论支撑。

基于街区演替对出行拥堵影响的城市更新启示——以江苏淮安为例

城市街区演替的多维现象是各种城市问题持续劣化的微观成因,探明其中影响是实施城市更新行动的重要依据。针对江苏省淮安市107处城市街区,利用时空多源数据,采用逻辑降维、关联分析、地理加权回归等方法,构建可表征空间规模、交通设施、日常出行、社会经济及公共交通等演替现象的多维复合要素体系,揭示城市街区演替对交通出行拥堵的时空影响机理。影响机理表明空间规模与日常出行演替具有显著一致的正向影响,公共交通演替具有显著一致的负向影响,交通设施与社会经济的演替则不具显著影响。依循时空影响机理,结合可预见变化、官方指导意见和近期实践经验,情景模拟了全局性交通出行改善下各类街区更新的空间增容阙值,作为城市更新启示。

城市安全风险特征及对风险管理的启示

为提升城市安全风险管理的科学性、精准性、规范性,分析城市安全风险特征,提出对风险管理的启示。首先,分析风险的定义和内涵,建立城市安全风险的因果链模型,提出城市安全风险分类;然后,结合城市的静态和动态特征,分析4类城市安全风险的特征;最后,结合城市安全风险管理实践,提出通用性的及针对4类风险的城市安全风险管理启示。结果表明:城市安全风险表现为传统风险累积、新兴风险涌现、复杂风险加剧、极端风险频现的特征。应建立通用性的城市安全风险管理框架,以及具有针对性的风险评估和风险处置措施,并将其融入城市应急管理体系。

站城融合·空间整合 --我国“站城综合体”的概念解析与研究进展

我国站城融合发展刚刚起步,站城综合体作为铁路客站与城市空间整合的实现方式,成为建筑设计领域重要的议题。站城综合体在不同城市发展背景下的建设实施,形成了若干实践模式,对站城综合体的概念和脉络进行系统解析,厘清其建设共识、现状问题和发展方向,有助于系统地建构站城综合体的研究框架,并应对站城融合发展中的现实问题。以站城综合体为综述对象,从概念解析、建设特点、问题审视和主要议题四个方面对站城综合体的相关研究进行梳理归纳。首先明确站城融合发展是我国站城综合体建设的实际推动因素,辨析概念的内核与拓展,对站城综合体进行界定;然后分析国内外站城综合体建设的特点,并对我国站城综合体的问题现状进行总结;进而划分出国内站城综合体的发展阶段,在此基础上归纳出当前我国站城综合体研究的四个主要议题。研究提出我国站城综合体的相关研究应完善站城综合体在多层面的体系化建构,强化站城综合体在城市开发方面的研究,推进站城综合体评价体系前置介入设计,注重学科交叉融合实现研究方法的创新,并通过多体系交叉和跨尺度协同展开进一步的研究,对当下我国站城融合发展具有现实意义。

基于复杂网络分析的广东省城镇居民碳足迹研究

应用投入产出模型和复杂网络分析方法,计算了广东省城镇居民直接碳足迹、间接碳足迹,构建了城镇居民间接碳足迹复杂网络,并对碳足迹重点产业部门进行了结构分解分析。研究结果表明:(1)广东省城镇居民直接碳足迹的主要来源是汽油和液化石油气,间接碳足迹网络的核心产业部门是电力、热力的生产和供应业。(2)广东省城镇居民碳足迹的主要来源为间接碳足迹,对所构建的碳足迹网络进行整体结构和个体特征两方面的分析发现,城镇居民间接碳足迹网络的通达性逐年向好,但各产业部门之间的协同碳关联关系的发挥尚有提升空间。(3)根据产业部门在碳足迹网络中的地位和作用,运用相关指标将其划分为碳核心社区、碳中介社区、碳边缘社区,在对碳核心社区的结构分解分析中发现,碳排放强度效应均为减碳因素,消费水平效应、城镇化水平效应、人口效应为增碳因素,且消费水平效应的增碳贡献率最大。