Underground Space最新文献

{"title":"Physical and mechanical response of large-diameter shield tunnel lining structure under non-uniform fire: A full-scale fire test-based study","authors":"","doi":"10.1016/j.undsp.2024.06.001","DOIUrl":"10.1016/j.undsp.2024.06.001","url":null,"abstract":"<div><p>When a fire occurs in an underground shield tunnel, it can result in substantial property damage and cause permanent harm to the tunnel lining structure. This is especially true for large-diameter shield tunnels that have numerous segments and joints, and are exposed to specific fire conditions in certain areas. This paper constructs a full-scale shield tunnel fire test platform and conducts a non-uniform fire test using the lining system of a three-ring large-diameter shield tunnel with an inner diameter of 10.5 m. Based on the tests, the temperature field distribution, high-temperature bursting, cracking phenomena, and deformation under fire conditions are observed. Furthermore, the post-fire damage forms of tunnel lining structures are obtained through the post-fire ultimate loading test, and the corresponding mechanism is explained. The test results illustrate that the radial and circumferential distribution of internal temperature within the tunnel lining, as well as the radial temperature gradient distribution on the inner surface of the lining, have non-uniform distribution characteristics. As a result, the macroscopic phenomena of lining concrete bursting and crack development during the fire test mainly occur near the fire source, where the temperature rise gradient is the highest. In addition, the lining structure has a deformation characteristic of local outward expansion and cannot recover after the fire load is removed. The ultimate form of damage after the fire is dominated by crush damage from the inside out of the lining joints in the fire-exposed area. The above results serve as a foundation for future tunnel fire safety design and evaluation.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000825/pdfft?md5=8e388e786b80d4a679e702694beefa95&pid=1-s2.0-S2467967424000825-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid deep learning approach for rock tunnel deformation prediction based on spatio-temporal patterns","authors":"","doi":"10.1016/j.undsp.2024.04.008","DOIUrl":"10.1016/j.undsp.2024.04.008","url":null,"abstract":"<div><p>The ability to predict tunnel deformation holds great significance for ensuring the reliability, safety, and sustainability of tunnel structures. However, existing deformation prediction models often simplify or overlook the impact of spatial characteristics on deformation by treating it as a time series prediction issue. This study utilizes monitoring data from the Grand Canyon Tunnel and introduces an effective data-driven method for predicting tunnel deformation based on the spatio-temporal characteristics of the historical deformation of adjacent sections. The proposed model, a combination of graph attention network (GAT) and bidirectional long and short-term memory network (Bi-LSTM), is equipped with robust spatio-temporal predictive capabilities. Additionally, the study explores other possible spatial connections and the scalability of the model. The results indicate that the proposed model outperforms other deep learning models, achieving favorable root mean square error (<span><math><mrow><mi>RMSE</mi></mrow></math></span>), mean absolute error (<span><math><mrow><mi>MAE</mi></mrow></math></span>), and coefficient of determination (<span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span>) values of 0.34 mm, 0.23 mm, and 0.94, respectively. The graph structure based on intuitive spatial connections proves more suitable for meeting the challenges of predicting deformation. Integrating GAT-LSTM with transfer learning technology, remains stable performance when extended to other tunnels with limited data.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000813/pdfft?md5=553352262c269f7f53faaab720bd548a&pid=1-s2.0-S2467967424000813-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on instability mechanism and control of abandoned roadways in coal pillars recovery face: A case study","authors":"","doi":"10.1016/j.undsp.2024.05.001","DOIUrl":"10.1016/j.undsp.2024.05.001","url":null,"abstract":"<div><div>The abandoned roadways (ARs) in front of the longwall face catastrophic instability will seriously hamper mining progress, which is a complicated process related to the stress environment, the roadway section, and the mechanical properties of the surrounding rock. The cusp catastrophe theory is employed to establish a state identification model for the irregular coal pillar-roof system (CPRS) formed by the ARs and re-mining entries. To begin, the state discrimination equation (<em>Δp</em>) for the gradual CPRS is derived, and the critical value at which the system transitions into an unstable state under quasi-static conditions is determined. The results indicated that when 16.49 m ≤ <em>L</em> ≤ 22.63 m (<em>L</em> denotes the equivalent span of the intersection roof) and 0 &lt; <em>R</em>_e ≤ 2.61 m (<em>R</em>_e denotes the width of the elastic zone within the triangular coal pillar), the triangular CPRS is inherently unstable. Similarly, for trapezoidal CPRS configurations where the length <em>L</em>_m (the span of the right-angled trapezoid roof in the propulsion direction) varies from 4.0 to 12.60 m, the system is unstable as well. Subsequently, the model was further enhanced by accounting for the impact of the <em>P</em>_c (advance stress increment load), where a critical criterion for the catastrophic instability of the CPRS was proposed, which represented the external energy required to transition the CPRS from an unstable state to catastrophic instability in different mining stages. After that, the stability degree of the irregular coal pillar was categorized, and a coupling zoning control technology was applied to CPR operations. Field monitoring results demonstrated the effectiveness of the zoning control technology, providing valuable guidance for similar mining practices.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000801/pdfft?md5=da5b193741033ceb8356d3acd410aa05&pid=1-s2.0-S2467967424000801-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radial flow behaviors of a rough Beishan granite fracture under normal and thermal loadings","authors":"","doi":"10.1016/j.undsp.2024.04.006","DOIUrl":"10.1016/j.undsp.2024.04.006","url":null,"abstract":"<div><p>During the operation of a deep geological repository in crystalline rocks for disposal of high-level radioactive waste, understanding the seepage behaviors of fractured crystalline rocks under coupled thermo-hydro-mechanical conditions is essential for the performance assessment of deep geological repositories. In this study, radial flow tests on cylindrical Beishan granite specimens with a single artificial fracture were conducted using the MTS 815 rock mechanics testing system to investigate the influence of normal stress and temperature on radial flow behaviors of rough rock fractures. Steady state method was used to measure fracture permeability, and an axial extensometer was used to measure fracture deformation during compression. A three-dimensional blue light scanner was used to characterize fracture surface morphology. Experimental results indicate that fracture permeability decreases nonlinearly with the increase of normal stress or temperature, and normal stress has a more significant influence on fracture permeability than temperature. The evolution of three-dimensional non-uniform distribution of voids under compression was numerically obtained, and the variogram was employed to quantify the non-uniform distribution characteristics of mechanical apertures. In addition, a radial flow model considering non-uniform distribution of apertures is proposed to predict the normal stress- and temperature-dependent seepage behaviors of rock fractures, and the predictions were found to be in good agreement with experimental data.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000783/pdfft?md5=71e0e86eb2a98d0130ba426bca8443ad&pid=1-s2.0-S2467967424000783-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic performance study of immersed tunnel with longitudinal limit device of flexible joint","authors":"","doi":"10.1016/j.undsp.2024.04.007","DOIUrl":"10.1016/j.undsp.2024.04.007","url":null,"abstract":"<div><p>Flexible joints represent the most vulnerable aspect of the immersed tunnel, necessitating effective waterproofing and the transmission of forces between tunnel segments. However, the role of longitudinal limit devices in the seismic behavior of immersed tunnels is frequently overlooked in contemporary research on their seismic robustness. This study develops a longitudinal force model for flexible joints that incorporates the longitudinal limit device, building upon the beam-spring model of the immersed tunnel. Concurrently, a scaled partial experiment on the immersed tunnel’s flexible joint is undertaken, and validated and compared to the theoretical model. Subsequently, this model is utilized in the seismic assessment of the Ruyifang immersed tunnel. The computational findings revealed a considerable improvement in the seismic resilience of the immersed tunnel following the integration of longitudinal limit devices. With the incorporation of these devices, the opening of flexible joints diminished by 20% to 50% compared to scenarios lacking such devices. In addition, the peak acceleration of the tunnel segments’ mid-point structural response decreased by approximately 50%, accompanied by a significant reduction in the internal force response within the tunnel segments. As proposed in this research, the longitudinal force model for flexible joints under longitudinal limit devices represents the behavior of immersed tunnels under seismic stress more accurately. These numerical simulation outcomes also offer valuable insights for designing flexible joints in immersed tunnels.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000795/pdfft?md5=242d717c47bdf3fc56715b83905cadb4&pid=1-s2.0-S2467967424000795-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated approach of predicting rock stability in high mountain valley underground caverns","authors":"","doi":"10.1016/j.undsp.2024.04.005","DOIUrl":"10.1016/j.undsp.2024.04.005","url":null,"abstract":"<div><p>High mountain valleys are characterized by the development of intricate ground stress fields due to geological processes such as tectonic stress, river erosion, and rock weathering. These processes introduce considerable stability concerns in the surrounding rock formations for underground engineering projects in these regions, highlighting the imperative need for rigorous stability assessments during the design phase to ensure construction safety. This paper introduces an innovative approach for the pre-evaluation of the stability of surrounding rocks in underground caverns situated within high mountain valleys. The methodology comprises several pivotal steps. Initially, we conduct inverse calculations of the ground stress field in complex geological terrains, combining field monitoring and numerical simulations. Subsequently, we ascertain stress-strength ratios of the surrounding rocks using various rock strength criteria. To assess the stability characteristics of the surrounding rocks in the 1^# spillway cave within our project area, we employ numerical simulations to compute stress-strength ratios based on different rock strength criteria. Furthermore, we undertake a comparative analysis, utilizing data from the 5^# Underground Laboratory (Lab 5) of Jinping II Hydropower Station, aligning the chosen rock strength criterion with the damage characteristics of Lab 5′s surrounding rocks. This analysis serves as the cornerstone for evaluating other mechanical responses of the surrounding rocks, thereby validating the pre-evaluation methodology. Our pre-evaluation method takes into account the intricate geological evolution processes specific to high mountain valleys. It also considers the influence of the initial geostress field within the geological range of underground caverns. This comprehensive approach provides a robust foundation for the analysis and assessment of the stability of surrounding rocks, especially in high mountain valley areas, during the design phase of underground engineering projects. The insights derived from this analysis hold substantial practical significance for the effective guidance of such projects.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000746/pdfft?md5=0f212efa334d36d48b5f77f1824979d9&pid=1-s2.0-S2467967424000746-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MatDEM-based study of disc cutter force model in open TBM tunnels: Incorporating installation radius and synergistic effects","authors":"","doi":"10.1016/j.undsp.2024.02.008","DOIUrl":"10.1016/j.undsp.2024.02.008","url":null,"abstract":"<div><div>The prediction of rock cutting force is critical for tunnel boring machine performance and cutterhead design. This paper presents a novel model for rock cutting force prediction based on the Colorado School of Mines (CSM) model, which incorporates the installation position of disc cutters by introducing installation radius and synergistic effect factors. Linear cutting tests in the laboratory and large-scale rotary cutting simulations in MatDEM software were conducted to examine the impact of these factors. Results indicate that the normal and rolling forces increase and stabilize as the installation radius increases. The synergistic effect produces three force modes in a cutting circle, with mode α having the largest cutting force, mode β having a smaller force, and mode γ having the smallest force. The impact of installation radius and synergistic effect varies with rock-cutter parameters. Multiple regression analysis was used to determine the introduced factors. The proposed model was validated with rock strength and operation data from the Irtysh River conveyance project. The results demonstrate that the proposed model outperforms the CSM model in predicting cutting force in field conditions.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141852516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model test on cutterhead-soil interaction during shield tunneling and its theoretical model","authors":"","doi":"10.1016/j.undsp.2024.03.006","DOIUrl":"10.1016/j.undsp.2024.03.006","url":null,"abstract":"<div><p>This study aims to develop a rational theoretical model for cutterhead-soil interaction. The cutterhead-soil interaction mechanism is divided into two components: the cutting action of the cutter on the soil and the extrusion of the cutterhead on the soil. By enhancing the Mckyes–Ali model, we analyze and deduce the force state of the cutter during shield tunneling, obtaining a calculation method for determining the force on the cutter. Additionally, we conduct an in-depth analysis of the extrusion effect of the cutterhead on the soil during shield tunneling, utilizing the fundamental solution of the Kelvin problem. Based on these theoretical calculations, we validate the tunneling thrust and cutterhead torque of the shield using our self-developed multi-functional large-scale shield tunneling test platform. The test results demonstrate that the tunneling thrust and cutterhead torque derived from the established cutterhead-soil interaction model in this paper are relatively close to the experimental monitoring values. This provides a theoretical foundation for establishing reasonable shield tunneling loads.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000722/pdfft?md5=6100098abc815e1895e44ae09c9c2df5&pid=1-s2.0-S2467967424000722-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vibration transfer from underground train to multi-story building: Modelling and validation with in-situ test data","authors":"","doi":"10.1016/j.undsp.2024.04.004","DOIUrl":"10.1016/j.undsp.2024.04.004","url":null,"abstract":"<div><p>Excessive underground train-induced vibration becomes a serious environmental problem in cities. To investigate the vibration transfer from an underground train to a building nearby, an explicit-integration time-domain, three-dimensional finite element model is developed. The underground train, track, tunnel, soil layers and a typical multi-story building nearby are all fully coupled in this model. The complex geometries involving the track components and the building are all modelled in detail, which makes the simulation of vibration transfer more realistic from the underground train to the building. The model is validated with in-situ tests data and good agreements have been achieved between the numerical results and the experimental results both in time domain and frequency domain. The proposed model is applied to investigate the vibration transfer along the floors in the building and the influences of the soil stiffness on the vibration characteristics of the track-tunnel-soil-building system. It is found that the building vibration induced by an underground train is dominant at the frequency determined by the P2 resonance and influenced by the vibration modes of the building. The vertical vibration in the building decreases in a fluctuant pattern from the foundation to the top floor due to loss of high frequency contents and local modes. The vibration levels in different rooms at a same floor can be different due to the different local stiffness. A room with larger space thus smaller local stiffness usually has higher vibration level. Softer soil layers make the tunnel lining and the building have more low frequency vibration. The influence of the soil stiffness on the amplification scale along the floors of the building is found to be nonlinear and frequency-dependent, which needs to be further investigated.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000710/pdfft?md5=d73516275ef4edd5f9166ea38a8c8160&pid=1-s2.0-S2467967424000710-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141696351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of spatial layouts for underground facilities to achieve carbon neutrality in cities: A multi-agent system model","authors":"Lingxiang Wei ,&nbsp;Dongjun Guo ,&nbsp;Junyuan Ji ,&nbsp;Zhilong Chen ,&nbsp;Huapeng Hu ,&nbsp;Xiaoli Peng","doi":"10.1016/j.undsp.2024.03.005","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.03.005","url":null,"abstract":"<div><p>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.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S246796742400062X/pdfft?md5=6869e2d580c2e3bfac61c8356bb60278&pid=1-s2.0-S246796742400062X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}