Risk identification and risk mitigation during metro station construction by enlarging shield tunnel combined with cut-and-cover method

Constructing a metro station by enlarging shield tunnels combined with a mining/cut-and-cover method provides a new method to solve the contradictions of construction time limits of shield tunnels and stations. As a new-style construction method, there are several specific risks involved in the construction process. Based on the test section of Sanyuanqiao station on Beijing metro line 10, and combined with the existing methods of risk identification at present, including a review of world-wide operational experience of similar projects, the study of generic guidance on hazards associated with the type of work being undertaken, and discussions with qualified and experienced staff from the project team, etc., the specific risks during the construction process of the metro station constructed by enlarging shield tunnels combined with the cut-and-cover method are identified. The results show that the specific risks mainly come from three construction processes which include constructing upper enclosure structures, excavating the soil between shield tunnels and demolishing shield segments. Then relevant risk mitigation measures are put forward. The results can provide references for scheme improvement and a comprehensive risk assessment of the new-style construction method.

Analysis of the Development of the Commercial Space Around Metro Stations in Urban Core Areas Based on Place Making: A Case Study of Chunxi Road Metro Station in Chengdu

The metro is the most efficient and convenient public transport system in modern cities. For urban core areas in China, in which the metro was built later, there was more consideration for meeting the traffic needs of cities. However, there are few studies of collaborative planning for metro stations and their surrounding space. Thus, there is an urgent need to conduct research on collaborative planning for metro stations and their surrounding commercial space in urban core areas. Unlike conventional methods of integrated design of stations and cities, this paper, based on the theory of place spirit, took Chunxi Road Metro Station in Chengdu and its surrounding commercial space for example. It explored the pattern and characteristics of the place in the commercial space around the metro station, analyzed the strategies of cultural and commercial integration, as well as architecture, street, landscape and other aspects of the design method in the space, and explored the strategies of place-making and infiltration, providing a reference point for the development and place-making of the commercial space around metro stations in urban core areas.

Current Situation and Application of Commercial Complex in Metro Stations:A Case Study of Nanchang City

With the rapid development of China's urbanization process,people put forward higher requirements for the efficient use of limited land resources.Facing the huge pressure brought by factors such as land,transportation and environment,the means of transportation on the ground have long been unable to meet the needs of people in modern cities.Metro is favored by people because of its high speed,stability and large capacity,and has become the best choice to relieve congestion in the public transportation system.How to efficiently use land resources while constructing urban metro systems?This article sorts out the current status of commercial construction in Nanchang metros to study the application value of commercial complex in the metro stations of Nanchang,so as to provide some useful references for related theoretical research.

Research on Behavior on Travel Mode, Going to Metro Station at Ho Chi Minh City

This research presents an analysis of travel mode choice for trips to Ho Chi Minh City metro station. Research methods were inherited through a formula to calculate passenger traffic forecasts to predict passengers, going to the station. Based on the collected data of interviews, traffic surveys, and ＂Irwin ＆ Von Cube＂ function, forecast the proportion of travel mode, and use to go to the station and leaving from the station. The results of study are used for the purpose of calculating the size of the metro station parking lots and parking layout plan.

Translation of Metro Station Names in Guangzhou and Foshan from the Perspective of Symbolic Function of Translation Landscape

Guangzhou and Foshan enjoy relatively mature metro network.However,some names of metro stations are over-transliterated in Pinyin.Such a translation method is used in translating general names,nouns of locality and some names of tourist destinations.With translation landscape and linguistic landscape theories,the reasons and impacts of over-transliteration in Guangzhou and Foshan metro will be discussed from the perspective of symbolic function.English names of Metro stations in other cities serve as a reference so as to appropriate solutions.

Shaking table test on a tunnel-group metro station in rock site under harmonic excitation

A tunnel-group metro station built in rock site is composed of a group of tunnels.Different tunnels and their interconnections can show inconsistent responses during an earthquake.This study investigates the dynamic responses of such a metro station in a rock site,by shaking table tests.The lining structures of each tunnel and surrounding rock are modeled based on the similitude law;foam concrete and gypsum are used to model the ground-structure system,keeping relative stiffness consistent with that of the prototype.A series of harmonic waves are employed as excitations,input along the transverse and longitudinal direction of the shaking table.The discrepant responses caused by the structural irregularities are revealed by measurement of acceleration and strain of the model.Site characteristics are identified by the transfer function method in white noise cases.The test results show that the acceleration response and strain response of the structure are controlled by the ground.In particular,the acceleration amplification effect at the opening section of the station hall is more significant than that at the standard section under transverse excitation;the amplification effect of the structural opening is insignificant under longitudinal excitation.

Seismic responses of an intensively constructed metro station-passageway-shaft structure system

Intensive construction methods offer benefits for metro station development,yet they present challenges for seismic design due to the spatially asymmetric configuration of passageway-shaft structures.In this study,a detailed numerical model of a station-passageway-shaft structure system built using intensive construction methods was developed and the deformation and damage modes under seismic loadings were analyzed.The results indicate that inconsistent deformation between the shaft and the station generates interaction through the connecting passageway,leading to damage near the opening of the station structure and both ends of the connecting passageway Damage is more severe under longitudinal excitation.Compared with the opening plan that spans four segments,the opening plan that spans five segments exacerbates the overall degree of damage to the structure system.Under transverse excitation,the presence of interior structures intensifies the damage to the station and connecting passageway,while with such internal structure in place the impact is relatively minor under longitudinal excitation.Reinforcement with steel segments near the station opening can appreciably attenuate the damage.In contrast,introducing flexible joints at both ends of the connecting passageway intensifies the damage.Hence,reinforcement using steel segments emerges as an optimal seismic mitigation strategy.

Research on passenger flow control at metro transfer stations based on real-time flow calculation of streamlines

Purpose – The volume of passenger traffic at metro transfer stations serves as a pivotal metric for theorchestration of crowd flow management. Given the intricacies of crowd dynamics within these stations andthe recurrent instances of substantial passenger influxes, a methodology predicated on stochastic processesand the principle of user equilibrium is introduced to facilitate real-time traffic flow estimation within transferstation streamlines.Design/methodology/approach – The synthesis of stochastic process theory with streamline analysisengenders a probabilistic model of intra-station pedestrian traffic dynamics. Leveraging real-time passengerflow data procured from monitoring systems within the transfer station, a gradient descent optimizationtechnique is employed to minimize the cost function, thereby deducing the dynamic distribution of categorizedpassenger flows. Subsequently, adhering to the tenets of user equilibrium, the Frank–Wolfe algorithm isimplemented to allocate the intra-station categorized passenger flows across various streamlines, ascertainingthe traffic volume for each.Findings – Utilizing the Xiaozhai Station of the Xi’an Metro as a case study, the Anylogic simulation softwareis engaged to emulate the intra-station crowd dynamics, thereby substantiating the efficacy of the proposedpassenger flow estimation model. The derived solutions are instrumental in formulating a crowd controlstrategy for Xiaozhai Station during the peak interval from 17:30 to 18:00 on a designated day, yielding crowdmanagement interventions that offer insights for the orchestration of passenger flow and operationalgovernance within metro stations.Originality/value – The construction of an estimation methodology for the real-time streamline traffic flowaugments the model’s dataset, supplanting estimated values derived from surveys or historical datasets withreal-time computed traffic data, thereby enhancing the precision and immediacy of crowd flow managementwithin metro stations.

Cluster and characteristic analysis of Shanghai metro stations based on metro card and land-use data

Metro is an important form of public transport in Shanghai.Based on the metro card data,we conduct the cluster analysis of Shanghai metro stations according to the pattern of passenger flow changing with time.Then the characteristics of travel time and surrounding land use are investigated for different types of stations to explore the relationship between urban land-use characteristics and travel activities reflected by passenger flow at metro stations.It is found that the passenger flow pattern of metro stations is closely related to the location conditions of stations and its surrounding land-use patterns.Based on various characteristics,285 metro stations are classified into four types,including residential-oriented stations,employmentoriented stations,employment-residence-oriented stations,and integrated functionaloriented stations,reflecting the interaction between spontaneous travel behavior and urban land-use characteristics and providing a reference for optimizing the urban functional structure and the spatial allocation of facilities.

Study on forecasting the parameters of gas environment of metro station

In the crowded metro station,it is important to forecast the changes of environmental parameters for the normal operation of metro and the safety of passengers in the future.Artificial Neural Network(ANN)has a good perfor-mance on processing time series data.In order to accurately predict environmental parameters,this paper uses ANN method to build the forecasting model of environmental parameters.The forecasting model uses the external environment parameters of the station as input variables.Finally,the accuracy of the model is verified by the field data collected from the metro station.The results show that the mean relative error of the proposed method is within 10%.The forecasting model based on ANN in this paper can accurately forecast the internal environment parameters of the metro station in the future period and is of great significance of emergency prevention and decision-making.

《In a station of the Metro》在中国的翻译与阐释

庞德的《In a station of the Metro》一诗在中国的翻译与阐释存在很多不足，甚至出现了误读。这种误读有深刻的动因：中国古典诗歌及诗论影响了庞德诗歌及诗论．这种影响反过来左右着中国读者对意象派诗歌的理解。

Tension in In a Station of a Metro to Explore the Energy in Language

Pound's poem In a Station of a Metro is a masterpiece of imagism. Pound once talked about the energy in language, and American scholar Allen Tate told us that the meaning of poetry is its tension. Based on those two notions, this essay focuses on that how the tension in In a Station of a Metro presented and those tensions form harmony, fully releasing the energy in language in Pound's hand, enabling readers being fascinated for generations in that way.

Accident Analysis and Emergency Response Effect Research of the Deep Foundation Pit in Taiyuan Metro

Taking the deep foundation pit accident occurring at a station of metro Line 2 in Taiyuan as an example,the influence of the seepage and inrush of the foundation pit on the retaining structure and surrounding environment were studied under the geological conditions of the confined aquifer on the east coast of Fenhe River.The causes of deep foundation pit accident were also analyzed systematically based on the monitoring data,and various emergency measures were proposed to control the occurrence of secondary accident for deep foundation pit.The results showed that the occurrence of inrush for foundation pit was mainly caused by the insufficient dewatering.The development of the accident was effectively controlled by the adding of the dewatering wells,local grouting of retaining structure to stop seepage,surface grouting to reinforcement and uplift soil.The successful experience can provide some guidance to the construction of similar projects in the proposal.

Building Evacuate Module for Urban Underground Passages: Subway Station in Turkey

The primary goal of crowd evacuation in urban underground passages or subways is to evacuate as many evacuees as possible to safe areas in the shortest time when emergency events occur. This paper chooses the underground passages of one metro in Istanbul, Turkey as research object, and uses a study method which combines by sites investigation, field test and computer simulation of the creating new software. It is called Building Evacuate Module software. We present a depth analysis of the related factors which include the number and width of passage, channelization setting and the number of pedestrians with the evacuation time. And the influential effect of public opinion is explained by using big data technology. In addition, pedestrians evacuation condition are recorded in three evacuation period, the morning peak, common and evening peak by the observation and statistic obtained with video, and build the model to simulate the change of evacuation time with pedestrians. So it reveals when the number of pedestrians reaches to more than 200, evacuation time increases significantly and the field experiment and simulation condition are consistent basically.

地铁入口空间布局对室内空气质量的影响研究

城市地铁地处繁华地区,结构封闭,周边环境污染源较多,室内易积累污染物。本研究重点关注地铁口空间布局对室外颗粒物进入的影响,在调研中选取地铁站入口方向、顶棚形态、入口高宽比3个形态指标作为影响因子,经过实测验证CFD模型的可行性后,选择RNG k-ε模型模拟不同风速下各地铁口形态的室内污染情况。结果表明:(1)侧向比正向入口颗粒拦截率高一倍;(2)入口高宽比小于1∶1时入口宽度越大,地铁站整体空气质量越好;(3)顶棚形态对室内颗粒物的消减排列为:斜顶>平顶>无顶;(4)地铁口空间形态对不同直径的颗粒拦截效果不同。形态设计可以改善站内颗粒物进入情况,通过空气对流、回流减少室外污染物的直接灌入。

黄土地区洞桩法地铁车站边桩和中柱的受力变形机理

[目的]为了确保黄土地区洞桩法车站施工过程中重要竖向承重构件的稳定性,需要对施工过程中边桩和中柱的受力变形机理进行研究,并对最不利受力阶段边桩和中柱提出变形控制措施。[方法]以西安地铁2号线何家营站为研究背景,通过数值模拟与现场监测的方法,对施工过程中边桩的水平位移、钢筋内力、水平土压力及中柱应变展开研究。[结果及结论]扣拱施作以及站厅层和站台层土体开挖是边桩水平位移最不利的三个阶段,在这些关键阶段施工时,应在结构内部架设钢支撑并适当加固已扰动的地层;在桩梁和扣拱施作中,边桩主筋承受轴向压力,而在站内剩余土方施工阶段,边桩背土侧的钢筋由轴向压力逐渐转化为轴向拉力,且随着边桩埋深的增大,钢筋的轴向拉压力增长变缓;在扣拱初期支护施作中,土压力在边桩埋深6.6 m处达到最大值34.5 kPa,且随着边桩埋置深度增大,边桩的桩侧压力增长速率显著,因此车站内侧的土方开挖是控制边桩迎土侧土压力大小的关键阶段,必要时对桩后土体进行注浆加固有利于提高桩基的承载力;中跨扣拱施工时,中柱的应变呈现出先减小、后增大的趋势。

接驳地铁站的共享单车碳减排效益评估

为促进城市交通绿色低碳化发展,以接驳地铁站的共享单车为研究对象,量化共享单车在接驳地铁站时替代其他交通方式所降低的碳排放量,构建共享单车碳减排量时空矩阵,根据非负矩阵分解(Non-negative Matrix Factorization,NMF)识别共享单车碳减排情景,从多情景层面分析共享单车碳减排效益及其时空分布特征。结果显示:在全天层面,共享单车单次接驳的碳减排量为62.75 g;在多情景层面,共享单车碳减排效益存在时空差异;在时间上,各情景中碳减排量在不同时段达到峰值,早晚高峰期间的碳减排量占全天碳减排总量的45.26%;在空间上,各情景中均有明显的碳减排量高密度区域和次高密度区域,且不同情景之间这些区域的空间分布存在差异。研究成果可为城市交通减碳政策的制定提供参考。

地铁车站BIM模型信息完备性审查研究

随着智能建造的发展,三维正向设计逐渐替代了传统二维设计,对设计成果的交付审查也将同步转换为对建筑信息模型的审查。地铁建筑设计区别于其他建筑具备较强的功能性,在实际设计交付成果审查中,会存在错审率、漏项高等问题。为解决该问题,本文依据相关国家标准,构建适用于地铁车站建筑信息模型完备性审查的本体模型,同时集成工业基础类(IFC 4.0)实例信息、计算机规则技术,实现模型完备性审查。以地铁车站的建筑单元为例,实现地铁车站模型在方案设计阶段的交付工作。该方法的提出有助于促进整个建筑行业的信息化发展。

砂卵石地层浅埋地铁车站暗挖施工关键技术

研究目的:针对富水砂卵石地层地铁车站明挖法施工面临的道路交通问题,本文依托成都富水砂卵石地层首次采用暗挖法施工地铁车站的成功案例,对暗挖法施工关键工艺开展研究,指明了暗挖导洞设置及其开挖时序、地层超前预加固方式、初期支护类型、永临结合钢管柱以及拱形盖板扣拱等关键工艺,明确了富水砂卵石地层浅埋大跨地铁车站首次采用暗挖法施工的可行性。研究结论:(1)基于“化整为零”的思路,借助大刚度管幕超前支护,明确了导洞设置原则,采用多导洞法实施钢立柱与盖板(顶板)后,可按盖挖法理念完成超浅覆土下的地铁车站暗挖施工;(2)浅覆土管幕打设精度与地层扰动控制是富水砂卵石地层沉降控制的关键,应遵循“精准定位、及时纠偏,欠土顶进、严控超挖,先低速后匀速”的基本原则;(3)基于初期支护主要以被动承载为主,格栅钢架经济性好、施工方便,喷混后抗弯刚度增幅将近8倍,且大于工字钢喷混后等效抗弯刚度,宜采用格栅钢架;(4)顶部预埋倒L形钢板的“蛇形”中立柱,可实现两侧衬砌结构的有效连接与水平向有效传力,液压反循环钻机可满足小净空条件下高精度永临结合钢管柱施作需要;(5)本研究结论可为类似地层暗挖法车站施工提供借鉴与参考。

地铁车站工程专项方案施工风险耦合致险评估

研究目的:安全专项方案风险评审是保障地铁车站重大工程施工安全的重要基础。针对地铁车站工程施工方案人工风险评审缺乏多风险耦合考虑、评审效率低等问题,提出构建基于系统动力学的风险耦合模型评估方法,其安全风险评价结果能有效支持专项施工方案风险评审和现场安全管理。研究结论:(1)基于工程安全风险事件的作用特征分析,得到了安全风险系统的演化路径及风险事件间的耦合关系;(2)建立了基于系统动力学的专项方案施工风险评价模型,其获得的具有时空信息工程风险评价结果,符合工程实际且便于工程师理解;(3)本研究成果可为地铁车站重大工程安全风险自动评审、方案修订以及现场应用提供支持,具有良好的理论和实践价值。