Tunnelling and Underground Space Technology最新文献

{"title":"Characterizing water-bearing structure ahead of tunnel using full-decay induced polarization based on the fuzzy C-means clustering method","authors":"Lichao Nie ,&nbsp;Zhaoyang Deng ,&nbsp;Zhi-Qiang Li ,&nbsp;Zhicheng Song ,&nbsp;Shaoyang Dong","doi":"10.1016/j.tust.2024.106159","DOIUrl":"10.1016/j.tust.2024.106159","url":null,"abstract":"<div><div>The application of full-decay induced polarization offers additional potential to characterize water-bearing structures. The method enables inversion imaging of four parameters: zero-frequency resistivity, intrinsic polarizability, relaxation time, and frequency-dependent coefficient. Due to the inherent volume effect in electrical exploration, the inversion results often fail to accurately depict the scale of water-bearing structures. To address this limitation, we introduce the fuzzy C-means clustering constraint into the objective function of the full-decay induced polarization inversion. We propose a multi-parameter inversion method for full-decay induced polarization based on fuzzy C-means clustering. To address the inconsistent resolution of anomalies by each induced polarization parameter, we apply different constraints to the sensitivity matrix of each parameter, thereby balancing the resolution of anomalies across parameters. The four parameters are normalized to solve the problem of large order of magnitude gap between different parameters. Inversion imaging numerical simulations of typical water-bearing structures are carried out, and the results showed that the proposed tunnel full-decay induced polarization inversion method based on fuzzy C-mean clustering could effectively depict the position and morphology of the water-bearing structures. Additionally, an on-site application was carried out in the Yinchaojiliao Water Diversion Project, effectively identifying the water body in front of the tunnel face and guiding the on-site construction of the project. The tunnel full-decay induced polarization inversion method based on fuzzy C-mean clustering has the ability to locate and depict boundaries of water-bearing structures with high accuracy.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical behaviour of double lining with outer segmental lining and inner fibre reinforced concrete lining under internal water pressure","authors":"Wen-Ding Zhou ,&nbsp;Dong-Mei Zhang ,&nbsp;Xiang-Hong Bu ,&nbsp;Xiao-Hu Wang","doi":"10.1016/j.tust.2024.106151","DOIUrl":"10.1016/j.tust.2024.106151","url":null,"abstract":"<div><div>Double lining with outer segmental lining and inner reinforced concrete lining is extensively used for water conveyance tunnel with internal water pressure. In order to improve the performance of the double lining, the steel rebar and fibre reinforced concrete (R/FRC) is designed for inner lining to enhance the tensile strength of reinforced concrete (RC). Full-scale tests were conducted to compare the mechanical behaviour of double lining with inner RC and R/FRC linings. The test results showed that both types of lining failed in four stages: elastic stage, inner lining cracking stage, crack stabilization and segmental joint damage stage, and failure stage. The cracks firstly occurred in the inner lining near the segmental joints and then propagated to the whole inner lining ring. Finally, the crack width and segmental joint opening successively exceeded the thresholds, and the double lining failed until the breaking of segmental joints. Compared with inner RC lining, R/FRC lining had better performance in terms of the initial cracking load, cracking-control ability, post-cracking stiffness, service limit capacity of inner lining and waterproof capacity of segmental lining. The improvement ratios were 36.3%, 50.3%, 46.3%, 37.2% and 31.1%, respectively. The influences of fibre volume fraction, fibre aspect ratio, and reinforcement ratio of steel rebar on the mechanical performance of R/FRC lining were also investigated based on a previously proposed analytical model. The parametric analysis demonstrated that higher fibre volume fraction and fibre aspect ratio can result in more significant increase of mechanical performance of R/FRC lining. The steel fibres were found to have more significant effects on the post-cracking behaviour of the lining than same amounts of reinforcing bars. Finally, an optimized function was proposed to fulfil a balance of lining performance and economy. The experimental and analytical results indicated that R/FRC lining can substitute RC lining and perform higher mechanical performance in water conveyance tunnels.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic resilience assessment and multi-objective optimization decision-making for urban roadway tunnel system in the face of fire disaster","authors":"Honglei Sun ,&nbsp;Huijun Lan ,&nbsp;Zili He ,&nbsp;Xiaodong Pan ,&nbsp;Ranran Zhang ,&nbsp;Pengfei Zhang ,&nbsp;Junhao Tong","doi":"10.1016/j.tust.2024.106120","DOIUrl":"10.1016/j.tust.2024.106120","url":null,"abstract":"<div><div>The urban roadway tunnel system (URTS), as an infrastructure system that includes equipment and facilities, operational staff, and traffic participants, faces challenges arising from various potential fire threats. Existing studies on tunnel fire risk primarily focus on static assessment, neglecting dynamic changes over time, and insufficiently considering the complexity of tunnel composition, leading to incomplete identification of influential factors. Additionally, few studies were conducted to develop optimal operation and maintenance (O&amp;M) strategies under cost constraints. To bolster fire safety management of URTS, a fire framework that combines resilience assessment and optimization is proposed based on system resilience theory, Bayesian network (BN), and multi-objective optimization (MOPT) in this paper. The framework is applied to Hangzhou’s URTS. The results indicate that Hangzhou’s URTS has a current “Medium” fire resilience level of 0.640, decreasing to 0.568 in 20 years without scientific O&amp;M. The static and dynamic strategies are acquired through sensitivity and critical importance analysis, enhancing long-term fire resilience. Moreover, optimal strategies for varied investments in diverse periods are explored, considering O&amp;M costs and resilience levels. The fire resilience framework introduced herein can integrate into various infrastructure systems, effectively enhancing disaster resilience and promoting sustainable development.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing gas drainage and ventilation efficiency in underground coal mines: A hybrid expert decision approach for booster fan prioritization","authors":"Abiodun Ismail Lawal ,&nbsp;Moshood Onifade ,&nbsp;Sangki Kwon ,&nbsp;Manoj Khandelwal","doi":"10.1016/j.tust.2024.106153","DOIUrl":"10.1016/j.tust.2024.106153","url":null,"abstract":"<div><div>Expanding mining operations in goaf zones heightens gas production potential, posing challenges in maintaining adequate ventilation within development panels, consequently impacting coal production. Various strategies have been explored to enhance mine ventilation and gas drainage effectiveness. However, deficiencies persist in the proposed ventilation system for the Okaba underground coal mine, prompting this study’s necessity. Addressing these concerns, the study evaluates the feasibility of employing booster fans to mitigate the identified drawbacks. Prioritizing booster fans for airflow distribution in underground mines is a complex decision-making process, requiring an advanced expert system approach. To address this, the study proposes an intuitionistic-based fuzzy TOPSIS (IFT) method for booster fan prioritization in the Okaba mine. Results indicate that booster fan 4 (BF4) ranks highest, followed by booster fan 3 (BF3), consistent with fuzzy TOPSIS findings. Sensitivity analysis supports the predicted importance order, affirming the efficacy of the hybrid expert decision method in selecting a booster fan capable of enhancing the overall efficiency of gas drainage and ventilation systems in underground mines. This study introduces a Hybrid Expert Decision Approach that integrates IFT and traditional fuzzy TOPSIS methodologies. This hybrid approach is particularly novel because it combines the strengths of both methods to prioritize booster fans in underground coal mines.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532993","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":"Exploring the axial performance of protective sheathed rock bolts through large-scale testing","authors":"Hadi Nourizadeh ,&nbsp;Ali Mirzaghorbanali ,&nbsp;Kevin McDougall ,&nbsp;Naj Aziz","doi":"10.1016/j.tust.2024.106157","DOIUrl":"10.1016/j.tust.2024.106157","url":null,"abstract":"<div><div>Understanding the axial load transfer mechanism of rock bolts under diverse conditions is essential for optimizing reinforcement in rock structures, advancing our comprehension of rock support, and facilitating the design of robust engineering solutions. This paper reports the outcomes of an extensive experimental investigation, focusing on the axial behavior of protective sheathed rock bolts employed in corrosive environments, assessed through pullout tests. Three distinct testing setups were designed to evaluate comprehensively the performance of these rock bolts in various scenarios. The results indicated that the failure characteristics and axial behaviors of sheathed rock bolts differ significantly from conventional counterparts. The findings revealed two primary failure modes in sheathed rock bolts: bolt rupture and slip at the grout-sheath interface, based on the testing arrangement and encapsulation length. The lack of adhesion and interlocking at the grout-sheath interface prevents shear stress at the bolt-grout interface from reaching its maximum potential strength, resulting in grout damage manifesting as circumferential cracks. This, in turn, initiates crack formation, reducing the system’s bond strength. Additionally, it causes slip at the grout-sheath interface to occur at lower pullout loads. It can be inferred that the inner surface of the plastic sheath lacks the necessary structural integrity to withstand high loads, significantly impacting bond stress distribution and failure modes. The results demonstrate that the protective sheath remains intact up to an axial displacement of 28 mm, irrespective of the testing configuration. Additionally, it was observed that the maximum bond stress at the bolt-grout interface falls within the range of 6–8.7 MPa, which is below the shear strength of the grout. Consequently, achieving failure at the bolt-grout interface is not feasible.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533024","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":"Lower and upper bounds for the drained three-dimensional stability of shallow tunnels using the Extended Matsuoka-Nakai yield criterion","authors":"A.N. Antão ,&nbsp;M. Vicente da Silva","doi":"10.1016/j.tust.2024.106137","DOIUrl":"10.1016/j.tust.2024.106137","url":null,"abstract":"<div><div>The paper focuses on determining lower and upper approximations of the pressure required on the unlined part of a tunnel’s front under drained conditions. This work is carried out within the framework of classic limit analysis. In the last three decades, various approaches have been explored to enhance the understanding of the minimum pressure required for ensuring the stability of the massif during tunnel excavation under drained conditions. Methods for solving this problem are typically categorized as limit equilibrium methods, limit analysis methods, or elasto-plastic stress–strain calculations. However, the failure criterion used has almost invariably been the Mohr–Coulomb criterion. Despite its broad application, this criterion has certain limitations in evaluating the effect of the three principal stresses on the yield of earthy or rocky materials. Over time, alternative failure criteria have been proposed to address this issue, including one developed by Matsuoka and Nakai.</div><div>This work applies Limit Analysis theorems to this problem using an extended Matsuoka-Nakai criterion. Besides providing highly accurate stability factors for tunnels using this criterion, the novelty of this study also lies in the comparative analysis of numerical results with experimental data, demonstrating that the Matsuoka-Nakai criterion offers a more accurate model of the experimental data compared to the traditional Mohr–Coulomb approach.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532992","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":"Digital twins for urban underground space","authors":"Nandeesh Babanagar ,&nbsp;Brian Sheil ,&nbsp;Jelena Ninić ,&nbsp;Qianbing Zhang ,&nbsp;Stuart Hardy","doi":"10.1016/j.tust.2024.106140","DOIUrl":"10.1016/j.tust.2024.106140","url":null,"abstract":"<div><div>Digital twins (DTs) offer promising benefits to address several inherent problems in underground construction, yet confusion surrounds the concept due to its context-specific nature which hinders more widespread adoption. This paper seeks to clarify DT-related terminologies from a built environment perspective and define the features and maturity levels of DTs for underground spaces, considering their unique challenges. A layered architecture for constructing DTs is proposed, offering various options based on functionality, technological advancement, and expected value. Additionally, a comprehensive literature review of technologies enabling the development of digital twins for underground spaces is presented, including data-driven ground modelling, site investigation and design process integration with BIM, computational BIM, and advanced sensing and instrumentation. The paper identifies synergies between DTs and the observational method in geotechnical engineering, highlights research gaps, and proposes a transition to a prescriptive, knowledge-based DT. Furthermore, exemplar use cases of underground DTs throughout their lifecycle are explored, demonstrating their potential value.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532995","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":"Rate-dependent similarity theory for scaling the dynamic tensile responses and failure of underground concrete silos under soil explosions","authors":"Xieping Huang,&nbsp;Bin Zhu,&nbsp;Yunmin Chen","doi":"10.1016/j.tust.2024.106131","DOIUrl":"10.1016/j.tust.2024.106131","url":null,"abstract":"<div><div>The conventional similarity theory derived from dimensional analysis struggles with the well-known issue of non-scalability of material strain-rate effects between scaled models and prototypes. This limitation has significantly hindered the application of scaled model tests, particularly small-scale centrifugal model tests, in the study of structures against blast loading. To overcome this challenge, this study proposes a rate-dependent similarity theory for scaling the dynamic tensile responses and failure of large-scale underground concrete silos (46 m in height) subjected to large-yield soil explosions. The proposed theory includes a correction method derived from a verified dimensionless number, D_cs, which accurately reflects the overall bending-induced tensile response and failure mechanism of concrete silos. The correction strategy involves maintaining an equal D_cs between the scaled model and the prototype by adjusting the explosive weight and the concrete’s static tensile strength in the scaled model to account for differences in strain-rate effects. To verify the theory, a series of geometrically similar silo models with scaling factors <em>β</em> = 1, 1/2, 1/5, 1/10, 1/20, 1/50, and 1/100 were designed. High-fidelity numerical simulations were performed using a fully coupled numerical model encompassing the explosive-soil-silo system. The results demonstrate that, with the conventional dimensional analysis-based similarity theory, the tensile damage and failure of the scaled silo models differ significantly from those of the prototype. However, with the proposed rate-dependent similarity theory, the failure patterns of the silo models with <em>β</em> = 1 ∼ 1/100 are almost identical, indicating that the proposed theory can effectively address the troublesome issue of dissimilar material strain-rate effects between scaled models and prototypes. This similarity theory offers a solid theoretical foundation for designing scaled models that accurately reflect prototype behavior, thereby advancing the application of scaled model tests in the study of structures against blast loading.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A confident learning-based support vector machine for robust ground classification in noisy label environments","authors":"Xin-Yue Zhang ,&nbsp;Xiao-Ping Zhang ,&nbsp;Hong-Gan Yu ,&nbsp;Quan-Sheng Liu","doi":"10.1016/j.tust.2024.106128","DOIUrl":"10.1016/j.tust.2024.106128","url":null,"abstract":"<div><div>Geological labels obtained from field exploration have potential errors due to technique limitations and subjective interference, leading to noisy labels when developing ground-machine interaction models for TBM tunneling. The present study proposes a novel confident learning-based support vector machine (CL-SVM) to eliminate label noise, thereby improving the accuracy and credibility of ground classification. The proposed model optimizes confidence values for each label and recognizes those with low confidence values as potential noise. Its effectiveness and superiority are confirmed through a noise test. The results indicate that the maximum acceptable noise ratio of the CL-SVM is 35%, while that of the conventional SVM is only 10%. In addition, the CL-SVM consistently emerges as a superior performer compared to the SVM in noisy label environments. The CL-SVM is further verified through its application on a class-imbalanced dataset collected from a metro tunnel project in Wuhan, China. Here, the accuracy metric <em>F1-score</em> for the most noise-interfered class is significantly improved from 0.7273 to 0.88. To enhance the model’s practical value, a confidence criterion is established to evaluate the credibility of individual predictions, which requires reliable predictions to have higher confidence values than specified thresholds. Without prior knowledge of true sample labels, this criterion distinguishes mispredictions from correct predictions with a remarkable precision of 99.08%. In summary, the proposed CL-SVM exhibits significantly better robustness to noisy labels than conventional models, demonstrating great potential for ground perception in tunnel projects.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Failure mechanism of deep-buried and large cross-section subway station tunnel: Geo-mechanical model test and numerical investigation","authors":"Deng Gao ,&nbsp;Yusheng Shen ,&nbsp;Pengfa Zhou ,&nbsp;Andi Gou ,&nbsp;Mingyu Chang ,&nbsp;Jun Dong ,&nbsp;Kang Wu","doi":"10.1016/j.tust.2024.106148","DOIUrl":"10.1016/j.tust.2024.106148","url":null,"abstract":"<div><div>In some megacities, urban subway and municipal engineering are developing in the tendency of large cross-section and great buried depth, which brings a series of challenges to the design and construction of underground engineering. The mechanical characteristics and failure mechanism of tunnels have been paid more and more attention. Based on Xietaizi Subway Station tunnel in Chongqing, China, the paper carried out a geo-mechanical model test to simulated partial excavation processes of the large cross-section tunnel, integrating the resultant disturbances from partial excavation. The deformation and stress characteristics of the tunnel under different buried depths are analyzed, and the failure mechanism of large cross-section tunnel lining is investigated. The reliability of the research results is verified by the geo-mechanical model test and numerical simulation. The results indicate that under the pressure of the surrounding rock, the tunnel lining adjusts its internal forces primarily through deformation before transitioning to cracking, and retains earing capacity after the first crack appears. The tunnel structure experiences a process characterized by ‘elasticity-plasticity-injury-failure’. The tunnel section exhibits a ‘flattening’ deformation trend. The invert cracks are primarily distributed within a range of 0.5 times the tunnel span, while the vault cracks are mainly concentrated at the mid-span. Ultimately, the tunnel structure is compromised by the fracture of the invert’s middle section.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}