Subway Station Construction Research Articles

Numerical study on flow field of high-speed train passing through a new type of station

With the growing demand for efficient travel, tunnels are being lengthened and train speeds are being increased. High-speed subway brings new challenges to the flow environment of tunnel. Additionally, the emergence of express trains passing through stations without stopping has an enormous impact on the tunnel's and the station's flow field. This study focuses on a new type of station (NS) with overtaking and avoidance lines, allowing slow trains to stop for passengers to get on and off, while express trains pass through without stopping. The study analyzes pressure variation and wind speed when express trains pass through the NS without stopping. Different train speeds are taken into account. Based on this, the enhancement of station ventilation by utilizing the piston winds generated by express trains passing through NS is investigated. The air exchange effect and energy savings of the NS are explored. The results indicate that enhancing station air exchanges by fully utilizing piston wind saves about 190.68 kWh/day in mechanical ventilation energy consumption. This study contributes to the improvement of subway station construction and the advancement of subway train development. It can offer data assistance and theoretical direction for high-speed train operations.

Development of A Structural Equation Model of The Variables Affecting the Organizational Performance of The Mass Rapid Transit Systems of Thailand

Introduction: The development of the Thai transport system in the future must be based on the advancement of three aspects: personnel, technology, and research and development must be promoted for the operation of efficient innovative tools and management as key mechanisms in the transport system’s development. The master plan of the Ministry of Transport under Strategy 5 for the development of the Thai transport system within 20 years (2017-2036) stated about the need for and initiation of technology and innovation, as well as the promotion of research and development for the application of rapid advancements within these aspects so to develop the transport infrastructure and management, which would engender higher efficiency of future transport as well. Technology is required and is suitable for the analysis and evaluation of performance in the view of safety technological innovation for subway station construction. Objective: The main objective was to explore the development, congruence, and the indirect direct, and total effects of the variables affecting the organizational performance of the mass rapid transit systems of Thailand Method: This is quantitative research, collecting data from 385 executives and chiefs of organizations relating to the mass railway transit systems and private manufacturers participating in the project with state enterprise agencies. Result: Relationship between the two variables and among the multiple variables in conjunction with the estimation of the effects of the variables, which were obtained from the regression coefficients (coef.) of each individual relationship path following the hypothesis. The results indicated that all C.R. ( t-test) values were statistically significant ( > 1.96). Thus, every hypothesis was supported. Technology directly affects organizational performance (coef. = 0.143, p < 0.05). Technology directly affects innovation (coef. = 0.370, p < 0.001). Technology directly affects research and development (coef. = 0.786, p < 0.001). Research and development directly affects innovation (coef. = 0.624, p < 0.001). Research and development directly affects organizational performance (coef. = 0.449, p < 0.001). Innovation directly affects organizational performance (coef. = 0.372, p < 0.01). Conclusion: Technology, innovation, and research and development truly affect organizational performance. The industrial sector should be more encouraged to participate in technology learning and to step into the manufacturing chain for the development of Thailand’s rail transport system. This would also save foreign currency, create employment opportunities in the country, and have continual economic effects for the national monetary circulation, which would eventually pave the way to the enhancement as well as development of the people’s abilities in the future.

Subway station construction parallelly below existing double-cell tunnel without clearance

ABSTRACT A case of the Olympic Park Station of Beijing Subway Line 15 constructed parallelly below the Datun Road Tunnel without clearance using the pile-beam-arch (PBA) method was presented. Cross section, geological condition, and construction process of the subway station are illustrated. The strip foundation PBA approach was first adopted and the settlements of the existing tunnel due to new subway station construction are systematically monitored. Whereas this method could not satisfy the settlement requirements of the existing Datun Road Tunnel. The maximum settlement of the existing tunnel reaches 32.0 mm. Meanwhile, the maximum transverse differential settlement of the existing tunnel reaches 10.1 mm. The improved pile foundation PBA approach was proposed. The numerical simulation was performed to verify the feasibility. The results indicate that the pile foundation PBA approach is more efficient in existing tunnel settlement control than the strip foundation PBA approach. About 80% of the total settlement of the existing tunnel caused by subway station construction using the pile foundation PBA method is produced during the excavation of the drifts and the arches. The settlements of the original tunnel induced by the construction of the concourse and the platform account for about 20% of the total settlement. The increments are negligible after the completion of the concourse construction.

Analysis of the Factors Affecting the Construction of Subway Stations in Residential Areas

To design a more suitable scheme under different conditions so that subway stations can play their role better, this study investigated the construction elements of subway stations in residential areas. Metro stations in residential areas are generally located at the intersection of urban roads. As the “handover space” of the city, the construction principle should be based on people’s experience. As the core basis for traffic planning and future operation management, construction of subways in residential areas should take into consideration factors such as trip volume, distribution, and mode selection of residents, and be determined based on such mathematical models as the unit factor method, gravity model, and disaggregated analysis method. Station site selection is based on the point, line, and surface elements, and the importance of a station in the line network is judged by degree and betweenness centrality; the accessibility of the line network is determined by connectivity. In this study, the influencing factors of residential area subway station construction are divided into construction elements and site selection. Internal construction elements of stations include station entrances and exits, escalators, ticket machines, and transfer routes, and the conclusion of the mathematical model is used to select or give opinions about the internal construction elements of the subway. The point, line, and surface elements and the connection relationship between the subway and buses are used to determine the site selection of the subway. Furthermore, this paper discusses the three elements that affect the construction of the subway, comprehensively considers the functional requirements of the subway, and makes reasonable adjustments to each element. Finally, the requirements for the elements of the subway construction are determined.

Analysis and Field Measurement on the Internal Force Variation Laws of Steel Pipe Columns in Subway Stations

Steel pipe columns are an important component in subway station construction and with stand stress state and internal force during the construction process. Based on the engineering background of Beijing subway, this paper introduces the geological conditions, station structure types, and internal force monitoring of steel pipe columns of 10 subway stations constructed by the PBA method. The field monitoring indicates that the greatest change in the internal force of the steel pipe column occurs during stage 1 (beam, primary support, and secondary lining buckle arch construction stage), no matter pile foundation station or strip foundation station, which accounts for about 60% to 65% of the total axial force. When the left and right spans are not synchronously arched or excavated, the steel pipe column is subjected to uneven forces and bears a large bending moment is produced. When the depth of overburden is between 7 m and 15 m, the internal force of the steel pipe changes positively correlated with the overburden depth. During the construction process, the internal force of the steel pipe varies widely in the silty sand stratum. Also, the steel pipe columns in stations affected by groundwater bears about twice of the axial force compared with other stations are not affected by groundwater. In addition, the construction period is also a factor that affects changes in internal forces. This research is conducive to update the database of the world subway projects and can serve as a practical reference for similar geological condition.

Monitoring and modelling of PM2.5 concentration at subway station construction based on IoT and LSTM algorithm optimization

Fine particulate matter (PM2.5) generated during construction not only has great influences on the health of the workers, but also has a negative impact on the health of the surrounding public. In-depth study of PM2.5 during construction is of great significance to the environment and human health. Traditional prediction methods have limited consideration of influencing factors and low prediction accuracy. Therefore, this study proposed a Bayesian optimization-based Long Short-Time Method (LSTM) algorithm which can achieve effective PM2.5 prediction at construction sites. In this study, The Internet of Things (IoT) technology was used to conduct real-time monitoring of a subway station construction site in China for 6 months. The PM2.5 concentrations generated by different construction processes were obtained through data cleaning and analysis. The average PM2.5 increments for the excavation and support works, reinforcement works and concrete works were 17 μg/m 3 , 20 μg/m 3 , and 21 μg/m 3 , respectively. After that, feature extraction was performed by the gray correlation algorithm to eliminate redundant information. Then, a Bayesian optimization algorithm was introduced to tune the hyperparameters to optimize the LSTM model performance. Finally, the validity of the proposed model was verified using multiple base models. The results showed that the accuracy of the LSTM model was improved by 6% (R 2 from 0.88 to 0.94), after the Bayesian optimization. And the optimized model also has better evaluation indicators , with RMSE = 13.06μg/m 3 , MAE = 8.61μg/m 3 . It was proved that the method can effectively predict air pollution. • Using IoT technology to monitor construction site PM2.5. • Considering the impact of construction machinery activities on PM2.5 at construction sites. • Proposing a Bayesian optimization-based LSTM machine learning algorithm. • Validating the performance of the proposed algorithm against multiple underlying neural network models.

Monitoring System for the Construction of Arch Cover Method Subway Station Based on DT and IoT

Aiming at the problems of safety and monitoring beyond the existing experience in the construction of the subway stations with arch cover method in Dalian, China, combined with the real-time monitoring requirements of intelligent construction status, a multi-information construction monitoring system based on digital twin(DT) and Internet of Things(IoT) is proposed, and the digital twin 3D architecture is established. First, on the basis of the IoT monitoring experience of tunnel, the installation plan of the automatic monitoring device of the arch cover method subway station is clarified, and the sensor arrangement is carried out. Then, based on the Revit platform, the establishment of the main structure model of the station and the BIM parametric modeling technology of the sensors are realized, and the monitoring properties of the sensors are expanded. Finally, through the design of the BIM database and in the form of secondary development, a BIM-based construction information visualization monitoring system is established to realize the correlation between the sensor model and the monitoring data and achieve the effect of information visualization query and color change early warning. The system was initially applied at Shikui Road Station of Dalian Metro Line 5 and achieved good results. The system can intuitively reproduce and accurately describe the subway station construction status, which provides an advanced technical means for the informatization and visualization management of the construction of arch cover method subway stations.

Early Warning of the Construction Safety Risk of a Subway Station Based on the LSSVM Optimized by QPSO

Subway station projects are characterized by complex construction technology, complex site conditions, and being easily influenced by the surrounding environment; thus, construction safety accidents occur frequently. In order to improve the computing performance of the early risk warning system in subway station construction, a novel model based on least-squares support vector machines (LSSVM) optimized by quantum-behaved particle swarm optimization (QPSO) was proposed. First, early warning factors from five aspects (man, machine, management, material, and the environment) were selected based on accident causation theory and literature research. The data acquisition method of each risk factor was provided in detail. Then, the LSSVM with strong small sample analysis and nonlinear analysis abilities was chosen to give the early warning. To further ameliorate the early warning accuracy of the LSSVM, QPSO with a strong global retrieval ability was used to find the optimal calculation parameters of the LSSVM. Seventeen subway stations of Chengdu Metro Line 11 in China were picked as the empirical objects. The results demonstrated that the best regularization parameter was 1.742, and the best width parameter was 14.167. The number of misjudged samples of the proposed model was 1, and the early warning error rate was only 4.41%, which met the needs of engineering practice. Compared with the classic and latest methods, the proposed model was found to have a faster prediction speed and higher prediction accuracy.

Principle of a low-frequency transient electromagnetic radar system and its application in the detection of underground pipelines and voids

The road collapse caused by tunnel construction was highly related to the leakage of the underground pipeline and the presence of voids. Thus, underground pipelines and voids should be clearly surveyed to prevent road collapse accident. The transient electromagnetic radar (TER) was developed and applied to the detection of underground pipeline and voids in this study. Variation of apparent resistivity in different materials underground pipelines were studied and summarized by the validation test. The application effect of TER in the inspection and recognition of different pipelines was verified by urban road detection before the subway station construction. Meanwhile, the application effect of TER in the detection of voids and loose soil area under the urban road subgrade was explored and analyzed in an urban road. The results show that: (i) different pipeline could be detected and distinguished by the variation of apparent resistivity; (ii) information of position, depth, size, and material of the underground pipelines and pipe trench could be discovered and located by TER; (iii) due to the difference of apparent resistivity, voids and loose soil area under the subgrade of the road could be detected and located by abnormal reflection signal of the lower apparent resistivity by TER. Thus, to prevent the road collapse effectively, the research and development of TER in the urban road detection provided a new idea for the inspection of underground pipeline and voids.

Deformation Response and Safety Evaluation of Buildings Affected by Subway-Station Construction

Based on the sand and pebble stratum in the Beijing area, this paper studies the interaction between deep-foundation-pit excavation for subway stations and surrounding buildings using an orthogonal test. Moreover, it considers the relative position relationship between buildings and how the foundation pit is set up as well as different design schemes for foundation pits and the surrounding buildings. Results show that the horizontal distance s between the building and foundation pit and stiffness of the building itself have a clear impact on the differential settlement δij and relative deflection Δ, and the degree of deformation of the building near the corner of the foundation pit is complex. Simultaneously, based on numerical simulation results, the deformation characteristics and degree of deformation of the building under different relative position relationships with the foundation pit are analyzed. Finally, by establishing a relationship among the comprehensive deformation index Dj, surrounding environmental safety evaluation index Sj, and scheme safety grade Lj, a multiangle safety evaluation method for buildings affected by foundation-pit construction is formed, which can provide a reference for the research and design of similar projects.

Research on Surface Subsidence of Long-Span Underground Tunnel

In the process of urban rail transit construction, underground excavation method is often used in subway station construction. Based on a large number of measured data of Qingdao Metro Line 3, this paper analyzes and studies the ground subsidence law of long-span shallow buried excavation station. The research results show that vertical surface settlement will be caused by the excavation of both sides of the guide hole, but the settlement is relatively small, basically within −10 mm. Large surface settlement will occur during the middle or middle guide hole excavation, with a large settlement up to −30 mm. Through data fitting, it is found that the regression analysis using cubic polynomial of one degree can get better fitting effect. The horizontal surface variation rules of underground excavation stations are affected by the tunnel depth, geological conditions, management level of monitoring units, monitoring layout and monitoring accuracy, and so on. The differences in horizontal surface deformation and settlement between stations are large. Wannianquan Road Station basically conforms to the deformation law of ground settlement trough in Peck, and Junfeng Road Station directly above belongs to the whole subsidence type. This study has accumulated a large number of surface settlement monitoring data, which can provide a certain reference for the subsequent design of similar lines.

Environmental Risk Assessment of Subway Station Construction to Achieve Sustainability Using the Intuitionistic Fuzzy Analytic Hierarchy Process and Set Pair Analysis

Environmental risks have a significant impact on the sustainability of subway station construction projects. This paper proposes an environmental risk assessment model based on the intuitionistic fuzzy analytic hierarchy process (IFAHP) and set pair analysis (SPA) to deal with the ambiguity and uncertainty in the assessment. An index system for environmental risk assessment is established based on a literature review and the rough set method. Subsequently, the IFAHP is used to calculate the indicator weights to describe the certainty, uncertainty, and hesitation degree of expert decisions in the weighting calculation by means of affiliation, nonaffiliation, and hesitation. Finally, SPA, which can deal with the randomness, uncertainty, and ambiguity of the indicators, is used to assess environmental risk. A case study of two typical stations (Lushan Avenue Station and Huilong Road West Station) of Metro Line 11 in Chengdu, China, is conducted. The case study results are consistent with field surveys. The evaluation results of the proposed model are more objective and reasonable than those of the traditional analytic hierarchy process, the entropy weight method, fuzzy comprehensive evaluation, grey correlation analysis, and technique for order of preference by similarity to an ideal solution (TOPSIS). The research results prove the scientific validity and superiority of the proposed model.

Design and Application of Risk Early Warning System for Subway Station Construction Based on Building Information Modeling Real-Time Model

The problems faced by subway stations in the construction process are more complex than those by overground buildings. Therefore, the construction risk for such structures is highly unpredictable and the risk management is difficult. Building information modeling (BIM) technology has strong visualization, simulation, and integration characteristics that make it conducive to the development of a risk early warning system for underground engineering. According to the functional requirements of risk early warning for subway stations, a risk early warning system based on a BIM real-time construction model is designed in this study for a subway station construction. The operation process of the risk early warning system is established through the grey prediction method to propose the operation method of the early warning system. The early warning system is applied to the Xiangjiang New Town Station of Changsha Metro Line 4 in China to verify its feasibility.

The Application of Computer Bim Assisted Secondary Development Technology in The Structural Design of Prefabricated Subway Station

In view of the demand for collaborative management in subway station engineering construction, this paper, by referring to the experience of manufacturing industry development, attempts to introduce the synergic and virtual manufacturing concepts that have been successfully used in manufacturing industry into subway station construction engineering, and discusses the integrated collaborative design mode and implementation path of BIM based railway station construction from macro to micro. The concept of prefabricated building and the characteristics of BIM technology can complement each other in comprehensive coordination and many other aspects. The deep integration of the two is conducive to the rapid development of industrialization, information technology and intelligence in the field of subway construction[1].

Study on Settlement and Deformation of Urban Viaduct Caused by Subway Station Construction under Complicated Conditions

With the rapid development of urbanization, the speed of constructing urban underground space and ground foundation engineering is accelerated. With the shortage of land resources, the distance between underground engineering and surface engineering is getting closer and closer, and the contradictions and problems between projects are becoming more and more serious. Based on the new subway station, this paper passes the existing urban viaduct in a short distance. The settlement and deformation of pile foundation and buildings caused by the excavation of the subway station is studied by using ROCSCIENCE software and site monitoring method. The potential risk sources around the station are pile foundations 18.5 m away, residential buildings 15 m away, storm water pipes 7.3 m away, and high‐pressure gas pipes at 5.6 m. According to the construction requirements of pile foundation settlement deformation during metro station excavation, we set up construction standards. The settlement of the buildings and pipelines around the metro station should not exceed 3 mm, and the horizontal displacement should not exceed 2 mm. The diaphragm wall is adopted to surround the subway station, and the ground is reinforced by advanced grouting. The results show that, during the excavation of the foundation pit of the metro station, the ground and the building will have obvious settlement deformation and the depth of deformation can reach 9 mm, which is more than the allowable value. The settlement deformation of the ground and the surrounding buildings can be controlled within 3 mm by strengthening the foundation pit support and ground advance‐grouting reinforcement. The control of construction deformation can meet the construction requirements.

软岩深埋地铁车站初支拱盖法施工WBS-RBS-AHP风险评估

软岩深埋地铁车站初支拱盖法施工WBS-RBS-AHP风险评估

Ground surface settlement response to subway station construction activities using pile–beam–arch method

A pile–beam–arch method is a shallow tunneling method suitable for constructing urban subway stations with dense surface traffic. The main construction process can be simplified into four stages: excavation of pilot tunnels, installation of piles and beams, installation of arches, and excavation of soil inside the subway station. This study uses numerical calculations to investigate the development law of ground surface settlement during the construction of subway stations. The results indicate that surface settlement gradually increases in the first three stages and rebounds after the fourth stage. Further, pilot tunnel excavation and arch installation are identified as key stages for controlling the surface settlement. Based on these facts, the effects of the sequence of pilot tunnel excavation and the spacing and cross-sectional area of the columns on the surface settlement are studied. The results show that the sequence of pilot tunnel excavation has a significant effect on the development of the surface settlement trough. Further, column spacing and surface settlement exhibit a linear relationship, wherein a shorter spacing leading to low surface settlement. The cross-sectional area of the column exhibits a nonlinear relationship with the surface settlement; the surface settlement is stable when the cross-sectional dimensions are 1.5. × 1.5 m. The Peck formula and stochastic medium theory are used to predict the surface settlement in the pilot tunnel excavation stage. The results are 30%–50% higher than that in the numerical calculation, which indicates their safety and conservatism. The results of this study provide a reference for the selection of construction parameters and the prediction of surface settlement in similar projects.

Risk Analysis and Control Factors Based on Excavation of a Large Underground Subway Station under Construction

Considering the convenience of pedestrian transfer, reasonable structural stress and beautiful shape design, most subway stations adopt symmetrical design. At present, the new subway station is developing in the direction of a multidimensional space, as well as a large scale, and complex structure. Tunnel construction also presents unpredictability, coupling amplification and high risks. For example, a subway extension project involves construction, which would affect the normal use of the subway or damage its structure. Based on excavation of the largest underground subway station under construction in China, the Erligou station extension project (line 16 of Beijing Metro), and using theoretical analysis, numerical simulation, monitoring data, and other research methods, this paper quantitatively analyzes the risk of a large space station’s construction process on the adjacent existing station structure and track, as well as highlights key, high-risk sub-projects, or construction steps, combined with specific engineering measures to ensure safety during construction of a new station. The general rules concerning large space subway station construction are further summarized to provide reference for similar projects.

Grouting Reinforcement Technology of Weak Fractured Rock Mass in Subway Open-cut Station

In the process of subway open-cut station construction, excavation deformation seriously threatens the safety of municipal pipelines and buildings. To ensure the effectiveness of grouting reinforcement, drilling exploration and pressure water test were conducted on the basis of the grouting reinforcement project of the excavation of an open-pit station in Qingdao metro, the permeability coefficient and crack characteristics were studied, and the equivalent crack width was calculated on the basis of cubic law. To determine the injectability index of grout and realize the optimal selection of grouting materials, the statistical distribution law of the equivalent crack width was analyzed on the basis of the Pareto distribution, and an effective method of grout selection was proposed. The PQT curve in the grouting process was analyzed by flow dimension theory to realize the dynamic adjustment of the grouting process. Finally, the grouting reinforcement effect was evaluated on the basis of the core sample and borehole TV. Results show that if the permeability coefficient is subject to Pareto distribution with parameters tmin and k, then the distribution curve of the permeability coefficient in the logarithmic coordinate is a straight line; the equivalent crack width obtained on the basis of the cubic law is also subject to the Pareto distribution with parameters bmin and 3k. Therefore, the equivalent crack width distribution curve can be obtained to provide a basis for the grout selection.

Research on Surface Settlement of Subway Station Construction Using Pile-Beam-Arch Approach

The pile-beam-arch (PBA) approach is illustrated as a creative construction method in shallow-buried tunneling excavation of subway construction. Attentions have been paid to this method due to its unique advantages of construction technology. Subway station construction by using PBA approach will make disturbance to the ground surface. Research on surface deformation caused by PBA approach is of great significance to the surrounding environment and its structure. The example of subway construction in Beijing is presented as the research background, a three-dimensional model is established by using the Midas-GTS finite element numerical simulation software to simulate the practical excavation support conditions, and to analyze the surface settlement, the initial support structure settlement and crustal stress caused by PBA construction method.