Development Of Underground Space Research Articles

Optimisation of Parameters and Application of Green Recyclable Precast Hollow Steel Pipe Concrete Supports

Underground space development is a crucial approach to addressing traffic congestion in China’s cities, especially through underground construction. However, the traditional pit internal support system, particularly the concrete internal support system, has significant drawbacks. These include high energy consumption and carbon emissions, which are increasingly prominent issues. In this paper, a hollow precast concrete-filled steel tube (H-CFST) internal support system is proposed and a node connection scheme is designed. Through numerical simulation, the load-bearing characteristics of H-CFST with different aspect ratios, hollow ratios, hoop thicknesses, and hoop lengths are investigated, and the optimal design parameters are obtained. Finally, following a field application, monitoring data reveal that the precast H-CFST internal support demonstrates superior load-bearing capacity compared to the concrete internal support, successfully meeting the criteria for replacement of the concrete support.

Reshaping port-city relationships through underground logistics system: A mixed qualitative approach

Against the backdrop of explosive growth in freight demand, the negative impacts of the traditional road-system-based port-city logistics mode on urban transportation, environment and safety have become prominent livelihood issues, as well as significant economic and social problems. Port-city underground logistics system (PC-ULS) has been widely recognized as an innovative way to ensure the sustainable development of port cities. However, the influence mechanism of PC-ULS on the port-city relationships is still unclear. Thus, this paper attempts to explore the PC-ULS-based port-city relationships formation process and the main influencing factors using a mixed qualitative approach. The social, economic and environmental impacts of PC-ULS on the development of port cities were systematically analyzed using the Shanghe Port ULS and Shanghai Port ULS as the case studies. The results show that the impacts generated by PC-ULS are positive and widely distributed across the economic sphere, port-city traffic, logistics governance, urban equity, stakeholders, ports, and urban spaces, as well as ecological sustainability. Furthermore, the urban planning, technology compatibility and engineering risk related factors have a strong impact on the PC-ULS implementation. A set of incentive policies has been designed to promote the effectiveness of PC-ULS. The findings provide a unique perspective on underground space development and utilization to address port-city conflicts, as well as a reasonable implementation pathway for PC-ULS application.

Construction of Utility Tunnel power supply and distribution system

As an underground structure that can accommodate multiple municipal pipelines, the utility tunnel can not only coordinate the planning, construction, and management of various municipal pipelines, but also achieve intensive development of urban underground space. In theory, any municipal pipeline can be included in the utility tunnel, thereby eradicating phenomena such as "road zippers" and "aerial spider webs" in the urban construction process. As a massive underground structure, the utility tunnel has its own electricity demand. Only by constructing a safe and stable power supply and distribution system inside the pipe gallery can it effectively ensure personal safety and the reliability of pipeline operation.

Ecological and geological security risk assessment of underground space development in cold and arid canyon cities-Taking Ping'an District, Haidong City, Qinghai Province, as an example.

The ecological and geological problems caused by the rise of groundwater level due to the development of underground space in cold and arid canyon cities are particularly typical. Reasonably assessing the ecological and geological security risks of utilizing underground space is conducive to reducing the occurrence of ecological and geological problems during the construction and operation of underground engineering projects. Taking Ping'an District of Haidong City as an example, the topography and geomorphology of the research area were investigated in the field, and the distribution of topography and geomorphology in the research area was understood; through geological drilling and geotechnical engineering testing, the distribution of different strata in the research area was obtained; through pumping and seepage experiments, the recharge, runoff, and discharge relationship between surface water and groundwater in the research area and the water abundance of different strata are obtained, and the causes and mechanisms of geological safety risks in forest and grassland ecosystems, farmland ecosystems, and human settlements ecosystems were analyzed based on literature. Corresponding ecological geological safety risk assessment index systems and methods were established, and the ecological geological safety risks before and after the development of underground rail transit projects along both banks of the Huangshui River in the study area were evaluated. PRACTITIONER POINTS: The development of underground space in canyon type cities can easily lead to ecological and geological problems. Taking Haidong City, Qinghai Province, as an example, this study investigates the causes of ecological and geological problems caused by the development of underground spaces in canyon type cities. An ecological geological security risk assessment index system and method for canyon-type cities were established. An evaluation was conducted on the ecological and geological safety risks before and after the development of the underground rail transit projects on both sides of the research area.

Suitability Evaluation of Urban Underground Space Development: A Case Study of Qingdao City

Urban underground space, as an underutilized land resource, holds tremendous potential and value. Efficient and rational development and utilization of this resource are key to addressing current urban challenges. This study takes the main urban area of Qingdao City as an example and establishes a comprehensive evaluation system for the suitability of urban underground space development at different depth levels through the integration of geological, hydrological, and urban planning factors. By utilizing the Analytic Hierarchy Process to assign weights to evaluation criteria within the system, both a multi-objective linear weighting function model and a fuzzy comprehensive evaluation model are employed to assess the suitability of underground space development. The results delineate the distribution of underground space development suitability within the study area. Comparative analysis of the two models reveals that the fuzzy comprehensive evaluation model offers a more detailed and comprehensive reflection of the complexity and diversity of underground space development, providing forward-looking and insightful evaluation results for urban planning and development. The evaluation indicates that certain streets within the main urban area of Qingdao exhibit excellent prospects for underground space development.

Scenario spatial planning evaluation model for subsidence-economic resilience environment in geohazard prone-coastal megacities: urban underground space (UUS) development in Shanghai by year 2035

Scenario spatial planning evaluation model for subsidence-economic resilience environment in geohazard prone-coastal megacities: urban underground space (UUS) development in Shanghai by year 2035

Optimization of spatial layouts for underground facilities to achieve carbon neutrality in cities: A multi-agent system model

Subways, underground logistics systems and underground parking, as the primary facilities types of underground, contribute significantly to the achievement of carbon–neutral cities by moving surface transportation to underground, thereby releasing surface space for the creation of more urban blue-green space for carbon sink. Therefore, in-depth studies on carbon neutrality strategies as well as reliable layout optimization solutions of these three types of underground facilities are required. This study proposes a spatial layout optimization strategy for carbon neutrality using underground hydrogen storage and geothermal energy for these three types of underground facilities employing a multi-agent system model. First, three spatial layout relationships, competition, coordination, and followership, between five underground facilities that contribute to emission reduction were investigated. Second, the implementation steps for optimizing the spatial layout of underground facilities were determined by defining the behavioral guidelines for spatial environment, underground facility, and synergistic agent. Finally, using the Tianfu New District in Chengdu City, China, as a case study, layouts of underground facilities under three different underground space development scenarios were simulated to verify the model. The findings of this study address the gap in the research on underground spatial facilities and their layout optimization in response to emission reduction. This study provided a significant reference for the study of underground space and underground resources at the planning level to aid in achieving carbon–neutral cities.

Diffusion mechanism of fracture grouting in rock mass with flowing water

Grouting is a widely used geotechnical procedure known for its strong empirical properties. It has been extensively utilized for sealing subterranean water and strengthening soil and rock masses in their original locations in underground mining and underground space development. The diffusion mechanism of grouting in fractured rock is affected by the geological environment and slurry performance, which should be better revealed and characterized. In this paper, we take the surrounding rock of the roadway as the research object, consider the stress condition of the injected rock and time-dependent viscosity of the slurry, and establish fracture grouting diffusion model based on the rock composite fracture criterion. The grout strengthening mechanism is discussed based on a transparent fracture replica grouting test. According to the different transport characteristics of the slurry interacting with flowing water, it is divided into the following four areas grout-water balance area, grout loss area, stagnation area and water passage. The grout plugging mode is divided into two categories according to its final diffusion pattern: cross-section type water plugging mode and water-drop plugging mode. The pressure monitoring data of the test verified the two grout plugging modes. The diffusion distance of cis-reverse water derived in this study was in good agreement with the experimental results in grouting early stage. The research results can provide a theoretical basis for grouting engineering design.

Ensuring the stability of deep boilers of high-rise buildings

In today's conditions, the development of underground space can rightly be considered one of the most important and dynamic directions in civil and industrial construction at the worldlevel. In Ukraine, underground construction is important in connection with Russia's aggressive war. Underground and buried structures are most actively built in large cities and megacities. The main reasons for the need to use underground space in cities include the lack of free territories within historically formed buildings and requirements for urban infrastructure development. Today, the underground space is used not onlyfor the placement of engineering communicationsand transport facilities, but also for the construction of public complexes, multi-story underground garages and parking lots, shopping centers, as well asburied parts of residential and office buildings. Structural solutions for underground and buried structures, as well as their construction methods, depend on spatial planning solutions, purpose, depth of laying, engineering-geological, climatic and seismic construction conditions, surface loads, and the proximity of other buildings and buildings. Today, the maximum depth of pits designed inurban conditions usually do not exceed 25-30 m, and the number of underground floors is five to six. Given the growing demand for underground space, especially in densely populated areas, designers and engineers face a number of challengesthat require innovative approaches and modern technologies. This includes the use of the latest methods of geotechnical modeling, the use of highquality materials that ensure the durability and safety of structures, and the implementation of effective water drainage and waterproofing systems. Particular attention should be paid to safety issues during the construction and operation of underground structures, as they may be exposed to natural and man-made factors, such as groundwater, soil movement, and seismic activity. An important aspect is also the provision of comfortable conditions for people using underground facilities, which includes ventilation, lighting and evacuation routes. Scientific research and the experience of international projects demonstrate that the correct use of underground space can significantly increase the efficiency of the use of urban areas, contribute to the steady development of cities and improve the quality of life of their residents. Investments in underground construction are becoming more and more justified in view of the long-term benefits and theneed to adapt to the conditions of the modern urban environment. In general, underground construction is an important direction that has significant potential for development and improvement in the future, responding to the challenges of time and contributing to the development of modern infrastructure.

Grey relation analysis and multiple criteria decision analysis method model for suitability evaluation of underground space development

Underground space is an important asset for urban development, but its development comes with inherent risks. Therefore, in order to evaluate the risk of underground space development, we utilized 3D modeling and grey relational analysis (GRA) for decision-making, and evaluated underground space development through attribute modeling. First, the underground space was categorized into 4 layers according to depth and 15 important influencing factors were identified. Then, the weights of these factors (soft soil thickness, liquefaction index of saturated sand, etc.) were determined using analytic hierarchy process (AHP), criteria importance through intercriteria correlation (CRITIC), and GRA. Finally, the study area was divided into 1,197,778 evaluation units, each measuring 30 m × 30 m. The suitability of each unit was evaluated using the Multiple Criteria Decision Analysis (MCDA) combined with the GRA method. The experimental results show a commendable performance compared to the combined “AHP + multilevel exponential superposition” approach. In addition, the computing efficiency is reduced by about 30%, the stability is improved by at least 20%, and the reliability is improved by about 10%. The study enhances the decision-making integration of GRA, MCDA and underground space, improves the efficiency and accuracy of underground space risk evaluation, and provides a valuable basis for the field related to underground space development. Code is available at https://github.com/NX-first/underground-space-engineering-development.git.

A Brief Discussion on Sustainable Application Strategies of BIM Technology in Underground Space Development

With the acceleration of urbanization, the development of underground space has become an important way to alleviate the shortage of urban land and improve the comprehensive carrying capacity of the city. However, the development of underground space faces many challenges, such as technical difficulty, high cost and environmental impact. With its innovative application in engineering design, construction and management, building information modeling (BIM) technology provides a new solution for the efficient, safe and environmentally friendly development of underground space. The purpose of this study is to explore the application strategy of BIM technology in the development of underground space, and to analyze how it can promote the sustainability of underground space development.Firstly , this paper analyzes the current situation, challenges and the importance of sustainability of underground space development through literature review, and summarizes the development and application of BIM technology. Then, the principle and function of BIM technology are studied, and its application potential and strategy in the development of underground space are discussed. Through case analysis, the application of BIM technology in different stages of planning and design, construction management and operation and maintenance management is discussed in depth, and the application strategy and evaluation framework to promote the sustainability of underground space development are put forward. Finally, the , which provides a scientific basis for the decision-making of underground space development, and puts forward a series of practical suggestions for the application of BIM technology in underground space development. Despite the limitations of the study, such as the limited number of cases and the lack of discussion on the deep application of BIM technology, this study provides a new perspective and method for the sustainability of underground space development, which has important theoretical and practical significance for urban planners and engineering circles.

Centrifuge model test of the influence of tunnel excavation with different spacings on existing tunnels

The continuous development and utilization of underground space has led to an increasing number of short-distance constructions between new and existing tunnels. New tunnel construction affects the surrounding strata and destroys the structure and operation of the adjacent existing tunnel. Therefore, investigating the influence of new tunnels on the deformation of existing tunnels is crucial. Four centrifugal model tests simulating tunnel excavation processes were conducted to study the influence of tunnel excavation with different spacings on existing tunnels. Liquid was drained one section at a time to simulate the formation loss ratio produced by tunnel excavation and unloading during centrifuge operation, which eliminated the error caused by centrifuge shutdown–restart. Test results indicated that new tunnel excavation led to uneven settlement of the existing tunnel, and the settlement of the existing tunnel was greater than that of the two sides. Under the same burying condition of the new tunnel, the smaller the net distance between the new and existing tunnels, the greater the influence on the vertical and horizontal displacement of the existing tunnel, and the smaller the settlement of the ground surface. New tunnel excavation caused tensile stress near the excavation surface of the existing tunnel. A smaller clear distance resulted in a higher tensile stress. The centrifugal model tests provide technical support for tunnel construction and underground space development.

Investigation of creep characteristics and microscopic mechanism of cemented-soil subjected to freeze-thaw

With the development of underground construction, higher safety demands have been placed on construction methods. The improved freezing method, which combines artificial ground freezing and cemented soil stabilization techniques, is more suitable for studying the typical creep characteristics of muddy clay in Shanghai. However, research on the creep behavior of freeze-thaw cemented-soil is limited. In this study, the creep characteristics of freeze-thawed cemented soil were investigated through triaxial creep tests, and the micromechanism was explored using scanning electron microscopy (SEM). The results indicate that the creep deformation of freeze-thawed cemented soil is higher than that of non-freeze-thawed cemented soil. The freezing temperature decreased with an increase in deformation. By analyzing SEM images, the porosities of non-freeze-thawed cemented-soil and soil freeze-thawed at -5°C, -15°C, and -25°C, were extracted, which were 28.5%, 28.7%, 30.1%, and 39.1% respectively. During the freeze-thaw cycle, both the soil and cemented soil particles undergo movement and reordering. Freeze-thaw exacerbates creep degradation because frost heave weakens particle adhesion and affects structural stability. These results provide a scientific reference for the development of underground spaces in soft areas.

Optimization for bilevel spatial configuration of underground space surrounding high-speed railway station in China from the perspective of urban morphology

The rapid growth of high-speed railways has led to the development of underground spaces surrounding high-speed railway stations (USSHRSs). The evolution of USSHRS has enhanced the space utilization efficiency. As USSHRSs expand, the layout of the underground connectivity network becomes increasingly intricate. Additionally, pedestrian behavior in USSHRSs transitions from mere passing to longer stays, and its spatial configuration becomes more difficult to evaluate. To date, studies have mostly focused on the structural analysis or inner underground space relationship of USSHRSs. A research gap exists in the field of USSHRS spatial configuration from the perspective of urban development. To fill this research gap, this study focused on the spatial configuration of the USSHRS from the perspective of urban morphology and established a quantitative analysis method for USSHRSs at both global and local levels. At the global level, we devised a method for measuring the USSHRS spatial configuration using pedestrian composite accessibility based on a complex network. At the local level, we used space syntax to study the inner spatial configuration problems of USSHRSs. Finally, we used the Shanghai Hongqiao Station (Shanghai, China) as a case study. The results revealed that the spatial configuration optimization of the USSHRS must improve the connectivity efficiency of the USSHRS, and the corresponding functional layout should also be optimized towards a centralized layout. This study aims to provide decision-making support for the planning and layout of complicated USSHRS and to highlight the role of USSHRS in urban sustainable development.

Cluster analysis of underground space in the core area of new districts from the perspective of urban morphology

Extensive underground space development worldwide has significantly contributed to the sustainability of social, ecological, and economic growth. In view of the tendency towards haphazard urban sprawling during the development of new areas in China, underground spaces have been increasingly utilized to create sustainable and resilient urban built environments. However, insufficient attention has been paid to their morphological characteristics, resulting in a lack of sustainable and resilient underground space morphological planning and design techniques. To bridge this gap, we established a computational morphology indicator system pertaining to underground spaces, considering land use, spatial distribution, and street networks. We selected 20 underground spaces in well-developed core areas of new districts in China. Hierarchical cluster analysis was adopted to investigate the morphological features of underground spaces. Additionally, the typology of underground space morphology and the corresponding characteristics were systematically summarized to facilitate decision-making for different patterns of underground space planning.

Research on the Driving Factors and Prediction Model of Urban Underground Space Demand in China

The development and utilization of urban underground space (UUS) have emerged as critical strategies to address the challenges posed by urban population growth and land resource depletion. Accurate prediction of UUS demand serves as the cornerstone for scientifically planning underground space and promoting sustainable urban development. In this study, statistical analysis methods were used to investigate the relationship between potential driving factors and UUS demand based on collected data from 16 cities in China. The identification of primary driving factors involves correlation, path, and determination coefficient analyses. Subsequently, univariate regression, multiple linear regression, and LASSO regression methods are employed to construct prediction models for UUS demand. Additionally, the link between historical data and UUS demand in each city was studied separately. The findings reveal that GDP per km2 and GDP per capita comprehensively capture the influence of urban population, economy, and transportation on UUS demand. Notably, GDP per km2 makes the most significant contribution to the proposed regression models, followed by GDP per capita. The application of LASSO regression proves effective in selecting potential factors while maximizing data utilization, presenting itself as a valuable auxiliary tool for UUS planning.

Water inrush-induced failure during deep excavation for a metro station in karst regions in Shenzhen, China: Cause diagnosis and post-accident restoration

With the rapid development of urban underground space in karst areas, water inrush disasters during deep excavations have become widespread. However, there is a notable scarcity of comprehensive systematic studies on the causes of these disasters and environmental responses to them, and the required post-disaster restoration measures. This study investigates several water inrush disasters that occurred during the excavation for the Longdong Village Station on Shenzhen Metro Line 16, China. Through an extensive review of the geological and hydrological conditions, design and construction plan, and field monitoring data, several potential causes of the water inrush-induced failure were revealed, including i) special natural karst geology and hydrogeological conditions, ii) imprecise geological pre-investigation owing to limitations of geological prospecting technology, and iii) possibly unreasonable geological drilling and excavation operations. The magnitudes of all the monitoring items rarely varied throughout the implementation of the post-disaster restoration measures, which demonstrated the success of the measures and plans adopted after the water inrush accidents. This case provides a reference for the prevention of similar water inrush disasters and the required post-disaster restoration measures.

Toward Healthy Underground Spaces: A Review of Underground Environmental Design Factors and Their Impacts on Users' Physiological and Psychological Health.

This study aims to review and synthesize what design factors are associated with the physiological and psychological health of occupants in underground spaces. The development of underground spaces offers options to global challenges, such as traffic congestion, urban overcrowding, the revitalization of dormant underground areas, disaster mitigation, and adaptation to extreme environments. Despite these advantages, concerns persist about potential adverse effects on human health in these environments. This situation underlines the necessity of systematically identifying concerns and perceptions related to health in underground spaces. A narrative literature review was conducted to examine the relationship between design factors and health factors across 21 empirical studies. Based on the review of the identified literature, a relationship diagram was developed to depict the interconnections between the identified design and health factors. The analysis identified design factors related to the air, sound, light, nature, transport, and spatial context of underground spaces, each of which exerted relationships with occupants' physiological and psychological health factors. The relationship diagram indicated that the psychological factor "feeling of confinement" was mentioned most frequently, suggesting that it is one of the most extensively researched factors in this context. The relationship diagram aims to bridge the existing knowledge gap and set the stage for future research endeavors. The ultimate goal is to refine urban living standards by leveraging the potential of underground spaces while ensuring health and well-being.

Data driven assessment of rock mass quality in red-bed hilly area: a case study of Guang’an city, SW China

The evaluation of geological suitability for urban underground space (UUS) development is an indispensable prerequisite for its optimal utilization. As the actual carrier of underground facilities, the evaluation of rock mass quality plays a crucial role in assessing geological suitability. However, it is notable that the evaluation of rock mass quality has regrettably remained somewhat marginalized within the broader framework of the geological suitability assessment in recent years. The selection of pertinent indicators for the evaluation of rock mass quality inherently presents an appreciable degree of subjectivity. Predominantly subjective evaluation methods continue to dominate the field, while the application of objective algorithms, such as unsupervised clustering, remains in its nascent stage. Furthermore, there is a lack of comprehensive investigations into distinct combinations of attributes. This limitation confines the broader applicability of the evaluation outcomes in the context of urban underground space. Within this study, we meticulously amassed rock core test data from over 40 boreholes of engineering geological significance within the urban planning ambit of Guang'An City. Utilizing the K-means unsupervised clustering algorithm and the Principal Component Analysis (PCA) algorithm. We successfully conducted an unsupervised clustering procedure with nine distinct physical and mechanical attributes. This yielded an aggregation into five discernible clusters. Building upon the derived clustering outcomes, a stratification of rock mass quality was effectuated into three distinct tiers: Level 1 (characterized by pure sandstone), Level 2 (primarily dominated by sandstone), and Level 3 (denoting fair conditions predominantly influenced by mudstone). This structured stratification facilitates a relatively objective and comprehensive evaluation of rock mass quality within the context of the red-bed hilly terrain. In the course of this analytical trajectory, we conducted a dissection of the clustering efficacy. For strongly correlated attributes, we propose a preliminary dimensionality reduction procedure prior to the clustering endeavor. Moreover, we recommend intervals of 10 m for the stratified evaluation in red bed hilly urban terrains.

Peculiarities of urban planning organization of underground research complexes

The relevance of the construction and operation of underground research facilities specializing in the fields of astrophysics, particle physics, geophysics and biology has developed significantly over the past 30 years. Underground research facilities are able to provide the necessary conditions for conducting experimental studies of physical phenomena that go beyond the Standard Model of Physics. Among the publications devoted to the theoretical foundations of the development of underground urbanism, it is worth noting the works of E. Reynolds, R. Sterling, W. Breuer, and G. Haiko. The main aspects of the architectural and planning and volumetric-spatial structure of underground buildings and structures are outlined in the works of H. Admiral, A. Cornaro, J. Besner. The exploitation of underground space in the conditions of sustainable development of modern cities is studied in the works of L. von der Tann and S. Ritter, Fang-Le Peng, Yong-Kang Xiao. Ukrainian scientists have made a significant contribution to the theoretical issues of underground urbanism: S.V. Ryndyuk, M.A. Maksymenko. Prospects for the integrated development of underground space in Ukraine are highlighted in the works of T.O. Nishchyk. Scientific works of G.I. Gayko are devoted to the priority tasks of development of underground urbanism in Ukraine, assessment of risks of underground construction, historical development of underground space in Ukraine. The historical development of underground buildings and structures is also studied in the works of V. Biletskyi, L. Korkushko, A. Pleshkanovska. The overview of the planning structure of modern underground research complexes is presented in the articles by A. Ianni, A. Bettini, E. Coccia. The article presents a number of prerequisites that influence the choice of a site for the design of underground research complexes in Ukraine. Their brief description is presented. Based on a preliminary analysis of the world experience in designing this type of facilities, important criteria that should be used when choosing a design site are identified. A complete set of functional zones of the master plan of the above-ground territory of the underground research complex is defined. A number of basic recommendations have been formulated that should guide the designer in the development of the master plan.