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.

The Explore of Landscape Planning and Design of Urban Complex Based on the Patch-Corridor-MatrixModel

As intensive urban organization form, urban complex emerged with the fast urbanization of our country. Based on the Patch-Corridor-Matrix model, the author analyzed urban complex landscape structure from the macro, meso and micro level, and also analyzed the relationship between urban complex and urban systems, the interact between functional patches, the landscape process and requirement of people from the three levels, proposed the main points of the planning and design of the environment landscape of urban complex, expect the study above can benefit urban complex＇s practice projects.

“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.

Spatial Conformation Analysis of Urban Complex as Wanda Plaza in Chengdu City of China

Through analyzing the overall spatial conformation of Wanda Plaza in Chengdu City, a typical urban complex, the whole space was classified into external plaza space, internal business space and its connection with external space. Characteristics of such an urban complex and its contained correlation were elaborated from the perspectives of spatial conformation, organization technique and connotation. And it was proposed that the urban complex should be regarded as an organic whole with dynamic changes and mutually-influenced units, attractiveness of external space and cohesion of internal space, so as to define the organization techniques influencing regional spatial conformation and also practical significance of these techniques.

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".

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.

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.

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。

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。

基于混合用地模式识别的济南市老城区典型片区绿色空间降温效应分析

城市绿色空间可以通过生态系统服务调节功能有效缓解城市热岛效应,降低高温健康胁迫风险。城市中心城区特别是老城区建成环境具有高度异质性,复杂建成环境中绿色空间的降温效应,特别是混合用地模式中绿色空间的降温强度、阈值、形状等还需进一步明晰。在厘清城市热环境影响因素和绿色空间降温机制基础上,构建了“冷热岛分析提取-混合用地模式聚类识别-混合用地模式热效应分析-典型绿色空间降温效应分析”的研究框架。针对当前城市绿地指标失实、结构失衡、功能失调等现实问题,选择济南市老城区典型片区进行实证研究,重点分析了中层建筑混合用地模式中绿色空间的降温强度、降温面积阈值、形状及植被覆盖度等,总结了具有高降温效能的绿色空间模式,为促进城市健康人居环境发展提供借鉴。

微多普勒辅助的城市环境无人机编队检测方法

针对城市复杂环境下电磁环境复杂、多径杂波和干扰信号密集等现象,传统的无人机(UAV)检测方法通过获取回波信号提取目标多普勒信息进行检测,易受到环境影响导致检测效果不理想。该文提出微多普勒辅助的城市环境无人机编队检测方法,充分利用无人机的微动特征,能够在复杂环境下提高检测精度。首先,参数化建模表征城市复杂环境下无人机旋翼的雷达回波微多普勒信号,利用YOLOv5s检测微多普勒闪烁脉冲,有效提取位置信息;然后,引入雷达信号分选方法的脉冲重复间隔(PRI)变换,分类获得无人机编队数量;最后,利用Kmeans算法验证无人机编队检测方法的准确性。结果表明,所提方法在信噪比2 dB时7架无人机的检测精度高于90%,能够用于城市复杂环境存在干扰脉冲、多径效应、局部脉冲丢失的无人机编队检测。

地铁线网性能分析及最小化韧性损失恢复策略

为更好地分析地铁线网性能,优化其在扰动状态下的恢复策略,采用基于复杂网络的地铁线网性能分析方法,并提出最小化韧性损失恢复策略.鉴于地铁线网复杂网络特征,采用Space L拓扑方法处理地铁线网,并运用复杂网络理论计算线网内各站点的基本参数,包括线网的度、平均路径和线网效率等.其次根据韧性理论以线网效率作为性能指标求解各站点韧性损失,采用遗传算法求解站点恢复序列.最后,以福州市为例,分析其地铁线网的复杂网络特征并进行扰动仿真,比较在多站点失效情况下的最小化韧性损失恢复策略与随机恢复策略的恢复效果.研究结果表明:在多个地铁站点受到扰动失效,采用最小化韧性损失恢复策略能够令地铁线网性能在恢复期间仍处于较优水平,恢复效果明显优于具有不确定性的随机恢复策略.

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%.

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。

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。

考虑出行阻抗的城市群综合客运网络可达性

为阐明城市群综合客运交通网络的多层空间结构并丰富网络的功能属性,以耦合这一全新视角提出考虑城市交通换乘的城市群综合客运网络模型,并从出行费用与出行时间出发分析节点与网络的可达性。首先,基于复杂网络理论Space-P建模方法,将城市群中的客运站点抽象为网络中的节点并进行编号,以票价与出行时间标定边权,分别构建公路客运子网、铁路客运子网。其次,划设城市群中的各城市中心城区为独立的交通小区,将有城市公共交通、步行等换乘方式连接的节点间添加耦合边,构建耦合子网。再次,将两类客运子网通过耦合子网组合叠加为综合网络,改进传统网络效率指标,构建加权的阻抗效率指标评估节点与网络的阻抗可达性。最后,以成渝城市群为实例研究,构建成渝城市群综合客运网络并分析公路、铁路、综合网络的阻抗可达性。结果表明:多个节点的耦合使得这些节点的阻抗可达性较好,因此在研究城市群综合客运交通网络时,城市交通换乘是不可忽略的因素;综合网络的阻抗可达性相较于公路子网、铁路子网分别提升了83.4%,28.5%,公路与铁路客运子网的耦合提高了城市群客运交通网络的阻抗可达性;推进站点间、多种运输方式间的耦合协调,继而构建更加便捷顺畅的城市群综合客运交通网络,是降低旅客的出行成本的重要途径。

城市更新的矛盾性与复杂性——以广州微改造更新设计为例

由文丘里《建筑的复杂性与矛盾性》引发的思考,广州的“城”与“厂”“村”“市”“江”有着高密度水乡城市的复杂性,这里的城市更新存在着新与旧、保护与发展、质量与密度、投资与回报、改造与治理等一系列需要进行价值判断的矛盾性。城市是各个时代并存的动态结果,是多样、复合和拼贴的,城市更新中既需要“存异”,也需要“求同”,促进城市的边界互融、功能互融、要素互融与认知互融。本文归纳了TIT创意园、珠江琶醍、1906科技园等工业遗存更新及永庆坊、先锋社区街区改造等设计实践的经验,探索出打破边界、扩展公共空间、混合功能业态、保持集体记忆、城市增值等多维路径,使城市更新具有可持续性。