Tunnelling and Underground Space Technology最新文献

{"title":"A novel geological classification based grouting strategy in fractured rocks","authors":"Guowei Ma ,&nbsp;Yunteng Zhang ,&nbsp;Wen Nie ,&nbsp;Zhenjia Yang ,&nbsp;Yun Chen","doi":"10.1016/j.tust.2025.107148","DOIUrl":"10.1016/j.tust.2025.107148","url":null,"abstract":"<div><div>Highly complex and concealed geological conditions result in grouting parameter design relying mainly on empirical methods. This study proposes a geological classification based grouting strategy (GCGS), integrating a grouting geological classification model and a maximum grouting pressure model, to quantify the grouting parameters in the curtain grouting process. The grouting geological classification model is developed to calculate the critical fracture aperture for a fractal fracture network and guide the selection of grouting materials. The formation permeability obtained from the water pressure test and the fracture density captured through borehole imaging are combined to characterize the grouting geological property based on the proposed geological classification diagram. The maximum grouting pressure model is further proposed to determine the allowable grouting zone, considering the coupling process of the Bingham fluid flow and the mechanical effect based on the Model I center fracture model. Sensitivity analysis is carried out to investigate the influence of fracture geometry and fluid rheological properties on the maximum grouting pressure. The proposed GCGS is applied at field grouting tests at the Dongzhuang hydraulic project. A better grouting effect can be achieved when the grain size of the cement grout is appropriate for the grouting geological model and applied grouting pressure is in the allowable range obtained from the GCGS.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107148"},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261987","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":"Effect of fine water mist system layout on electric vehicle fire suppression in underground garages","authors":"Bin Chen ,&nbsp;Lizhong Yang ,&nbsp;Ruichao Wei","doi":"10.1016/j.tust.2025.107140","DOIUrl":"10.1016/j.tust.2025.107140","url":null,"abstract":"<div><div>The increasing prevalence of electric vehicle fires means that the fire evolution characteristics and the fire suppression effects of fine water mist on these fires in underground garages must be quantitatively analyzed. This study experimentally explores electric vehicle fire suppression in an underground garage under three conditions: no fine water mist suppression, a top fine water mist spray system, and a combined top and bottom fine water mist spray system. The top nozzle sprays the water mist vertically downward. In contrast, the bottom nozzle directs the water mist toward the vehicle’s underside. The results show that the combined spray system can act directly on the bottom of the vehicle, slowing down the temperature rise. Moreover, at 1.7 m in front of the vehicle, the temperature is reduced from 306 ℃ to 69 ℃, i.e., by 77.5 %. Compared with the absence of a fine water mist system, the time required for radiation to drop to the safe value is reduced by 14.05 % by the top fine water mist system. In contrast, the combined top and bottom fine water mist system reduced the time required for radiation to drop to the safe value by 84.10 %. Under top spray conditions, the fine water mist spray reduced the concentration of various gases during battery pack combustion. Under combined top and bottom spray conditions, fine water mist suppressed the production of CO₂, CO, and NO, while the amount of NO₂ increased. Adding the fine water mist can reduce the temperature and radiation in the underground garage. However, it would increase the concentration of certain toxic gases. This study provides data support for designing the layout of fine water mist systems in underground garages and fire protection strategies for electric vehicles.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107140"},"PeriodicalIF":7.4,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269267","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 dual-resolution acoustic-sensing robot for autonomous in-pipe inspection","authors":"Xiaoyu Sun ,&nbsp;Yicheng Yu ,&nbsp;Xudong Niu ,&nbsp;Zhenshan Wang ,&nbsp;Alexander R.K. Towlson ,&nbsp;Kirill V. Horoshenkov ,&nbsp;Anthony J. Croxford ,&nbsp;Bruce W. Drinkwater","doi":"10.1016/j.tust.2025.107133","DOIUrl":"10.1016/j.tust.2025.107133","url":null,"abstract":"<div><div>This paper presents the development of an acoustic-sensing robotic system designed for autonomous in-pipe inspection. Existing methods, such as camera-based visual sensing and laser-based distance scanning systems, offer high-resolution and rapid spatial data but are often unsuitable for long-term deployment in adverse environments. Recent developments show that acoustic sensing methods can offer power- and data-efficient inspection for long-term service. This paper explores autonomous in-pipe inspection using only acoustic measures for remote pipe monitoring. We propose a dual-resolution acoustic sensing strategy that employs low-frequency acoustic waves for long-range coarse sensing and navigation, paired with high-frequency acoustic waves for short-range, high-resolution imaging. A robotic system and corresponding data characterisation and classification method was developed based on this strategy, enabling autonomous inspection. Experimental findings show that the robot can effectively localise multiple features within the pipe setup, achieving an average localisation variation of 8 cm over a total length of 1800 cm. Additionally, the system effectively classifies features, specifically aligned pipe structures, tilted pipe structures, blockages and empty pipes, with an average accuracy of 76% during autonomous inspections.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107133"},"PeriodicalIF":7.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223417","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":"Fire source elevation effects on smoke transport in inclined tunnels: scaled experiments, synergistic mechanisms, and predictive model enhancements","authors":"Chaopeng Sun ,&nbsp;Miaocheng Weng ,&nbsp;Fang Liu ,&nbsp;Haoran Yang ,&nbsp;Kai Du ,&nbsp;Xiwen Lei","doi":"10.1016/j.tust.2025.107146","DOIUrl":"10.1016/j.tust.2025.107146","url":null,"abstract":"<div><div>Fire-induced smoke dynamics form a critical foundation for tunnel safety design. Existing studies on inclined tunnel fires predominantly adopt simplified ground-level fire source assumptions, neglecting the impact of elevation variations caused by vehicle type differences on smoke transport in urban scenarios. This study systematically investigates the influence mechanisms of plume state, fire source elevation, tunnel slope, and heat release rate (HRR) on induced air inflow velocity and smoke back-layering length through scaled experiments. Results reveal that while fire source elevation, slope, and HRR collectively alter plume-ceiling impingement states (e.g., transitions between weak/strong plumes), such alterations do not significantly alter the overall trends of induced air inflow velocity and smoke back-layering length. Induced air inflow velocity and smoke back-layering length show significant negative correlations with fire source elevation, though their sensitivity nonlinearly diminishes with increasing slope. Induced air inflow velocity exhibits synergistic enhancement with concurrent increases in HRR and slope, driven respectively by amplified tunnel temperature differentials and elevation differences. Conversely, smoke back-layering length demonstrates pronounced slope-dependent responses to HRR variations: higher HRRs amplify smoke back-layering length in low-slope configurations due to dominant thermal buoyancy effects, but this effect diminishes in steep slopes. Building upon these mechanisms, the revised predictive model of induced air inflow velocity and smoke back-layering length incorporating fire source elevation is developed and validated against experimental data, showing improved accuracy across varied fire elevation scenarios. These findings provide critical insights for optimizing smoke control strategies in urban inclined tunnels.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107146"},"PeriodicalIF":7.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223414","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":"Asymmetric loading effects and reinforcement strategies for double-arch tunnels in probabilistic jointed rock masses","authors":"Wangrong Li ,&nbsp;Weidong Lei ,&nbsp;Zaihong Li ,&nbsp;Fengwei Wu ,&nbsp;Rui Chen","doi":"10.1016/j.tust.2025.107144","DOIUrl":"10.1016/j.tust.2025.107144","url":null,"abstract":"<div><div>Double-arch tunnels constructed in randomly jointed rock masses are subjected to complex asymmetric loading, the induced mechanical behavior is not clearly understood, and the need for a comprehensive investigation is urgent. In this study, 3DEC discrete element modeling of a highway double-arch tunnel project was performed to reveal the effect of random joint parameters on tunnel mechanical behavior. The probabilistic jointed rock masses were modeled via Monte Carlo simulation and a discrete fracture network (DFN) model. The orthogonal experimental method was used to design a simulation scheme for evaluating the effects of key joint parameters (dip angle, trace length, density, strike, and set number) on the differential displacement of the surrounding rock mass, middle partition wall stability, and induced asymmetric stress. The joint dip angle and set number are the primary controlling parameters for surrounding rock mass displacement. The joint density most significantly affected the middle partition wall stability and overall asymmetric loading behavior, with the maximum difference in the asymmetric stress ratio reaching 7.7. A non-bias side tunnel first bench method combined with bias side unilateral extended rock bolt support can effectively reduce asymmetric surrounding rock displacement (by up to 80.0%) and middle partition wall displacement differences (by up to 24.4%). The results provide critical theoretical insights and practical guidance for optimizing the design and construction of double-arch tunnels in complex jointed rock mass conditions.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107144"},"PeriodicalIF":7.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223338","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 numerical study for assessing tunnelling-induced distortions of infilled structures","authors":"Yalin Yu ,&nbsp;Xiaoshuang Li ,&nbsp;Feng Chen ,&nbsp;Alec M. Marshall","doi":"10.1016/j.tust.2025.107125","DOIUrl":"10.1016/j.tust.2025.107125","url":null,"abstract":"<div><div>This study investigates the critical influence of masonry infill nonlinearity on tunnelling-induced responses of frame structures, employing a validated Two-Stage Analysis Method (TSAM). Departing from conventional elastic approaches, a refined elastoplastic constitutive model (CDP<span><math><msup><mrow></mrow><mrow><mo>∗</mo></mrow></msup></math></span>) is implemented for the infills to accurately capture their role in structural damage evaluation. The analysis accounts for the full three-dimensional geometry of the infilled frames, including infill dimensions, column cross-sections, slab thicknesses, and the spans between adjacent columns and between floors. The research investigates the influence of building eccentricity (<span><math><mrow><mi>e</mi><mo>/</mo><mi>B</mi></mrow></math></span>), soil–structure interaction (<span><math><msub><mrow><mi>μ</mi></mrow><mrow><mtext>soil</mtext></mrow></msub></math></span>), and frame–infill interface conditions (<span><math><msub><mrow><mi>μ</mi></mrow><mrow><mtext>infill</mtext></mrow></msub></math></span>) on structural behaviour. For both the soil–foundation and frame–infill interfaces, contact conditions are varied from fully smooth to rough by adjusting the frictional coefficient based on a Coulomb friction law. For each parameter, two types of frames with different transverse widths are considered to assess the effect of building width on the response. Validation of the two-stage analysis method is conducted against centrifuge modelling tests and advanced geotechnical analyses of tunnelling beneath bare frames. Results reveal that elastic models underestimate shear distortion (<span><math><mi>β</mi></math></span>) and tensile strain (<span><math><msubsup><mrow><mi>ɛ</mi></mrow><mrow><mn>99</mn></mrow><mrow><mi>t</mi></mrow></msubsup></math></span>), particularly in symmetric configurations (<span><math><mrow><mi>e</mi><mo>/</mo><mi>B</mi><mo>=</mo><mn>0</mn></mrow></math></span>) where infill plasticity dominates the response. This study proposes new guidelines to enhance current assessment frameworks for infilled frames, accounting for infill nonlinearity under different parameters of building eccentricity, soil–structure and frame-infill interfaces.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107125"},"PeriodicalIF":7.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223430","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":"Fatigue reliability assessment of TBM disc cutter bearings using multi-dimensional interference model","authors":"Jingxiu Ling ,&nbsp;Da Huang ,&nbsp;Jinke Xiong ,&nbsp;Jiacheng Shao","doi":"10.1016/j.tust.2025.107152","DOIUrl":"10.1016/j.tust.2025.107152","url":null,"abstract":"<div><div>Disc cutter bearings served as pivotal components in Tunnel Boring Machines (TBM), providing essential support, friction reduction, and precision transmission. During tunneling operations, these main bearings endured substantial alternating impact loads while demanding extended service life and operational reliability. Current research on bearing reliability remained constrained due to challenges in accurate load simulation and the prohibitive resource expenditure required for comprehensive reliability testing. This study employed a disc cutter structural model to investigate load transmission characteristics within the cutterhead system, establishing input conditions for bearing load spectrum analysis. Through numerical simulations, the maximum stress distribution and critical failure zones under unit loading conditions were identified. The quasi-static methodology was subsequently applied to derive stress histories at these critical regions, particularly the primary thrust roller–outer raceway interface. By integrating the stress-strength interference model with statistical theory, a dimensionless interference model was developed for reliability prediction under specified operational parameters. Analytical results demonstrated that stress amplitude distribution at critical zones followed a Weibull distribution (shape parameter = 0.67, scale parameter = 349.41), while service life adhered to a log-normal distribution. The established reliability curve revealed an inverse correlation between reliability and operational cycles, exhibiting rapid decline before 10⁵ cycles followed by gradual reduction. Beyond 10⁶ cycles, reliability diminished below 0.85. These findings provided theoretical foundations for rock fragmentation mechanics and fatigue reliability analysis of TBM rolling bearings.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107152"},"PeriodicalIF":7.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223429","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":"Investigation of waveguide synergistic rock fragmentation using a three-dimensional electromagnetic-thermal–mechanical coupled model","authors":"Junnan Ren ,&nbsp;Qixiang Yan ,&nbsp;Daihui Chen ,&nbsp;Jiangtao Wei","doi":"10.1016/j.tust.2025.107151","DOIUrl":"10.1016/j.tust.2025.107151","url":null,"abstract":"<div><div>Shield tunneling in hard rock faces challenges such as high cutter wear rates, driving the need for auxiliary rock-breaking methods. Microwave-assisted rock fragmentation has emerged as an effective auxiliary method for shield tunneling in hard rock formations, offering distinct advantages including volumetric heating, high fragmentation efficiency, and environmental friendliness. However, in large-diameter shield tunnels, a single waveguide proves inadequate for achieving the required extensive rock preconditioning coverage. This study presents a novel hard rock preconditioning strategy employing dual dielectric-loaded converging waveguide antennas (DDLCWA) and develops a comprehensive three-dimensional electromagnetic-thermal–mechanical (EM-T-M) coupled model to analyze the preconditioning effects. The results demonstrate that under dual-waveguide operation, the temperature field exhibits three characteristic zones: high-temperature, low-temperature, and transitional regions. Short-duration, low-power irradiation induces only minor temperature increases in the rock mass, generating insufficient thermal stress to cause damage. Conversely, high-power, prolonged irradiation leads to rapid temperature elevation in the rock beneath the waveguides, producing significant thermal stresses. These stresses result in block-type fragmentation patterns within the high-temperature zones and generate non-penetrating fractures in adjacent areas. The fragmentation pattern in the inter-waveguide region shows strong dependence on spacing configuration. Smaller spacings promote distinct block-type fragmentation, while larger spacings produce non-penetrating fractures of varying lengths. The proposed multi-waveguide synergistic strategy effectively expands the microwave-induced damage zone, successfully addressing the limited coverage issue inherent to single-waveguide systems.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107151"},"PeriodicalIF":7.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223431","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":"Interactions at the front face of EPB shield when drilling in sand","authors":"Adam Bezuijen","doi":"10.1016/j.tust.2025.107145","DOIUrl":"10.1016/j.tust.2025.107145","url":null,"abstract":"<div><div>The construction of a tunnel with a tunnel boring machine (TBM) influences the soil in front of the TBM. Excess pore pressures are measured in front of the TBM, which influence the stability of the soil. The magnitude of these pressures depends among others on the soil layering, drilling velocity, permeability of the soil and the sand-foam mixture and the pressure in the mixing chamber. The pressure buildup when drilling starts and the decay when drilling stops depends on the plastering properties of the slurry or the foam mixture. This paper describes the interactions between the soil and an earth pressure balance shield (EBP) TBM when drilling in saturated sand. It shows monitoring results and presents theory to describe the results from this monitoring in the field and from laboratory tests. Groundwater flow appears to be of importance on different scales: at the front face, in the foam-water-sand mixture and in the lamella between two foam bubbles.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107145"},"PeriodicalIF":7.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223432","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":"Effect of bypass duct size on the opening pressure of fire doors in an escape tunnel","authors":"Ke Zhong ,&nbsp;Liang Wang ,&nbsp;Qinghai Yang ,&nbsp;Shuhan Wang ,&nbsp;Danjie Wang ,&nbsp;He Li","doi":"10.1016/j.tust.2025.107139","DOIUrl":"10.1016/j.tust.2025.107139","url":null,"abstract":"<div><div>Emergency escape tunnel is increasingly being incorporated into urban transportation networks to ensure timely evacuation in the event of a tunnel fire. Pressure control within the escape tunnel is critical for ensuring safe evacuation and preventing smoke infiltration. This study investigated the effects of supply air pressure on various aspects of ventilation system performance, specifically focusing on supply airflow rate, bypass duct outlet pressure, and static pressure difference across fire door (SPFD). Numerical simulations were conducted to evaluate the relationship between supply air pressure and airflow rate, showing that differences in performance between cases with different bypass duct sizes became apparent when the bypass duct was opened. The study further examined the impact of supply air pressure on bypass duct outlet pressure and found that when the supply air pressure exceeded the opening threshold (i.e., 50 Pa), differences between cases became evident. The relationship between supply air pressure and SPFD was also explored, and the results showed that bypass duct size significantly influenced SPFD, with larger ducts providing better pressure regulation and maintaining SPFD below the critical opening pressure. Finally, the study explored how bypass duct size impacts pressure regulation at a supply air velocity of 7 m/s. The results indicated that increasing the bypass duct size enhanced pressure stability up to a certain threshold of 2.6 m², beyond which further increases had diminishing effects. The findings highlight the importance of optimizing bypass duct dimensions to ensure efficient pressure control without incurring unnecessary costs. A mathematical relationship between bypass duct area and SPFD was derived, which supports the design of ventilation systems that maintain safety and stability in emergency conditions.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107139"},"PeriodicalIF":7.4,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223335","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}