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.

地铁车站轨行区迂回隧道对其通风和热环境的影响

[目的]部分地铁车站由于周围空间限制无法将活塞风井设置在轨行区外侧,为满足通风需求可将活塞风井设置在车站轨行区内,并设置迂回隧道将活塞风井与轨行区外侧正线隧道相连。目前暂未有将迂回隧道应用于改善隧道通风和热环境的相关研究,因此有必要对类似工程进行分析。[方法]以包含迂回隧道的某条地铁线路为例,采用一维数值模拟方法,对某车站轨行区内设置活塞风井并增设迂回隧道的情况进行模拟计算,分析了车站轨行区设置迂回隧道对全线隧道活塞风量、活塞风井风量及隧道空气温度分布的影响。[结果及结论]迂回隧道位于车站出站端时,出站端的区间隧道活塞风量变化最大,最大增加了38.1 m^(3)/s;距迂回隧道最近的活塞风井风量变化最大;隧道空气温度变化最大区域主要在迂回隧道所在车站的轨行区,轨行区内活塞风井的进风作用导致该车站出站端轨行区空气温度快速下降,最大降低了1.8℃;迂回隧道的存在使轨行区车头停靠区域降温更多,且车站出站端迂回隧道对热环境的控制效果优于车站进站端迂回隧道。

大直径盾构切穿地下连续墙对既有地铁车站变形影响的仿真分析

[目的]盾构隧道掘进过程中切削穿越既有地下结构会对结构产生不利影响,需要对盾构穿越引起的结构及地层变形进行研究。[方法]依托南京建宁西路过江通道的超大直径盾构隧道切穿既有地铁车站地下连续墙实际工程,建立隧道-车站-地层的三维数值模型,研究隧道切穿车站地下连续墙与桩基时地面的沉降与车站结构的变形。[结果及结论]仿真研究结果表明,车站桩基对沉降控制作用明显,盾构掘进切除桩下部后,切口上方地表产生较大沉降;切穿地下连续墙后,墙体形成以被切处为中心的沉降槽,产生不均匀沉降;盾构切穿车站地下连续墙引起运营地铁线两股钢轨的差异沉降,但在安全控制指标范围内。该仿真预测性分析结果可为该工程后期施工与监测,也为同类盾构隧道切穿既有地下工程的施工优化提供参考。

集中回风模式下单跨拱形地下车站公共区气流组织模拟分析

[目的]单跨拱形地下车站因层高较高,并采用拱形顶板的特殊结构形式,对装修提出了较高要求。因此,在合理的气流组织前提下,有必要研究如何减少单跨拱形地下车站公共区的通风空调管线,为装修提供更大创新空间。[方法]以深圳某单跨拱形地下车站为例,提出了公共区采用集中回风模式,以及送风管兼排烟功能的设计思路;通过CFD(计算流体动力学)软件模拟分析在相同制冷量和相同送风温差的条件下,单送单回和集中回风两类送回风模式在单跨拱形地下车站公共区内的气流温度和速度分布规律,研究调整集中回风口位置对公共区气流组织的影响,并利用不均匀系数作为效果评价。[结果及结论]地下车站公共区采用集中回风模式,以及送风管兼排烟功能的设计可有效减少公共区的站厅风管数量约50%,截面积约40%,有效减少站台风管截面积约50%;采用公共区集中回风模式,集中回风口单独设置在站台,以及送风管兼排烟功能的布置方式,气流温度和速度分布均达到较优水平,能满足乘客的舒适度要求,可适用于单跨拱形地下车站公共区的气流组织。

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.

基于RFM模型的北京地铁站域类型识别及其更新策略

在城市存量发展的背景下,地铁站域逐渐成为城市更新的关键触媒。为探索以地铁站域分类为导向的城市更新新范式,引入RFM(Recency-Frequency一Monetary)模型作为理论框架,通过深入分析各站域的POI数据、人口密度和地价等关键指标,将北京地铁5号线沿线的23个站域划分为8种类型,包括重要价值站域、重要发展站域、重要保持站域、重要挽留站域、一般价值站域、一般发展站域、一般保持站域、一般挽留站域。在此基础之上,进一步为每一类型站域制定相应的更新策略,以期为地铁站域更新提供实证参考和理论指导,进而推动城市更新进程,实现城市空间的可持续优化。

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.

装配叠合整体式地铁地下车站轨顶风道施工技术探讨

针对目前地铁地下车站风道施工存在的工序复杂、工期长、投资大、空间狭小等问题,研发由风道侧墙及风道底板组成的轨顶风道结构体系。文章详细阐述装配叠合整体式地下车站轨顶风道施工技术的具体流程和操作要点,并总结诸多技术优势。轨顶风道通过吊装工具精确吊放,风道侧墙采用龙门架两点起吊方式提升至中板下方,举升至安装高度后通过升降机进行微调,以确保安装精度。该流程可保证安装质量,并实时监控轨顶风道的安装状态,一旦发现偏差可及时做出调整。通过实际工程的应用,显著提高预制构件吊装和模板安装的施工效率,节约工程成本,可为以后类似工程施工提供借鉴。

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。