Tunnelling and Underground Space Technology最新文献

{"title":"Experimental analysis of the failure modes and precursors of surrounding rocks in 3D-printed tunnels with rough fractures: Insights into the influence of excavation shapes","authors":"Boran Huang ,&nbsp;Peitao Wang ,&nbsp;Yijun Gao ,&nbsp;Qingru Liu ,&nbsp;Wei Yuan","doi":"10.1016/j.tust.2025.106510","DOIUrl":"10.1016/j.tust.2025.106510","url":null,"abstract":"<div><div>The rock surrounding tunnels typically exhibits rough structural surfaces with complex morphologies, making it difficult to understand their failure mechanisms and mechanical characteristics. In this study, 3D printing was used to create fractured rock specimens with different geometric excavation shapes. Compression tests and digital image correlation (DIC) analyses were conducted to investigate the mechanical properties, fracture patterns, and failure precursors during the loading process. The results indicate that the 3D-printed rock specimens can efficiently represent the failure behaviour of the surrounding rocks. Jointed rock masses with horseshoe-shaped roadways exhibited higher mechanical resistance. The identified fracture patterns showed monoclinic shear damage with a combination of compression and shear, suggesting ductile deformation. A notable, abrupt change in the shear-strain and strain-rate indices during loading corresponds to crack formation, and serves as a precursor to rock fracture. The study revealed that the changes in the shear-strain field aligned with the evolution of rock fractures. Among them, jointed rock masses featuring a horseshoe-shaped roadway exhibited the most prominent correlation, followed by those featuring elliptical and circular roadways. These findings demonstrate the potential of 3D printing and DIC analysis for rock mechanical testing, failure precursors, and forecasting. This highlights the utility of shear-strain indicators for identifying fracture precursors on rough structural surfaces of rocks surrounding roadways.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"160 ","pages":"Article 106510"},"PeriodicalIF":6.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519499","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":"Study on different influence factors of in-situ stress unloading by dynamic excavation in circular tunnel","authors":"Jun Zhou ,&nbsp;Jinshan Sun ,&nbsp;Guangming Zhao ,&nbsp;Chunliang Dong ,&nbsp;Xiangrui Meng","doi":"10.1016/j.tust.2025.106518","DOIUrl":"10.1016/j.tust.2025.106518","url":null,"abstract":"<div><div>With the depth of underground mining increase, the in-situ stress is more and more high, which may causes strong disturbance to surrounding rock. To study in-situ stress unloading in blasting excavation of roadway. The unloading influence factors with wave velocity, excavation radius and unloading time are discussed by defining unloading rate. The in-situ stress unloading experiments are performed by impacting different material models. And consider the unloading influence factors with axial stress, excavation radius and lithology in experiment. The results show that unloading stress is fluctuate during in-situ stress unloading, unloading stress decrease first, then increase, and tend to be stable finally. During in-situ stress unloading process, the unloading rate increases with the increase of rock wave velocity, and the more disturb severely of different rock velocity with the unloading rate increases. The unloading rate increases with the increase of rock excavation radius, and the larger scale disturb of different excavation radius with the unloading rate increases. The unloading rate increases with the decrease of unloading time, and the more dynamic disturb intensely of different unloading time with the unloading rate increases. The experiments show that radial cracks are generated by impact stress wave and circular cracks are generated by unloading stress wave. Comparing unloading result, hard rock material generate more damage area than soft rock material, unloading damage of soft rock material focus near excavation face and generate more cracks. Smaller excavation radius are not generate circular crack, it also shows that rock storage energy release completely need enough unloading space.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"160 ","pages":"Article 106518"},"PeriodicalIF":6.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519501","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":"Experimental research on the rotary rock-breaking effect of tunnel boring machine cutters assisted by microwave irradiation","authors":"Gaoming Lu ,&nbsp;Zhiyong Lu ,&nbsp;Yongsheng Liu ,&nbsp;Yangkai Zhang ,&nbsp;Wenchao Fan","doi":"10.1016/j.tust.2025.106512","DOIUrl":"10.1016/j.tust.2025.106512","url":null,"abstract":"<div><div>To deeply analyze the rock-breaking effect of tunnel boring machine (TBM) cutters assisted by microwave irradiation, rock-breaking experiments were conducted on microwave-irradiated rocks using reduced-scale TBM cutters. Influences of parameters including the microwave exposure time, microwave power, cutter spacing, same rolling distance (different rock-breaking depths), and penetration rate on rock-breaking marks, rock removal, wear loss of cutters, average cutter thrust, average cutterhead torque, and rock-breaking specific energy were explored. Research results show that under the same rotation diameter, increasing the microwave exposure time and microwave power decreases the wear loss of cutters, average cutter thrust, average cutterhead torque, and rock-breaking specific energy while increases the rock removal. If the cutter spacing is too large, the rock between adjacent cutting marks cannot be effectively exfoliated, the average cutter thrust and cutterhead torque enlarge, and the rock-breaking efficiency reduces. The wear loss of cutters is directly proportional to the rock-breaking depth. Under the current experimental conditions, using a large rock-breaking depth can exfoliate rock debris and improve the rock-breaking efficiency. A high penetration rate reduces the rotation number of the cutterhead, promotes the generation of rock debris, enlarges the rock removal, and improves the rock-breaking efficiency.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106512"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510203","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":"Three-dimensional numerical investigation of ground settlement caused by side-by-side twin tunnels","authors":"Md Shariful Islam ,&nbsp;Magued Iskander","doi":"10.1016/j.tust.2025.106509","DOIUrl":"10.1016/j.tust.2025.106509","url":null,"abstract":"<div><div>A parametric study using 3D finite element analyses was conducted to investigate settlement behavior and interactions between side-by-side twin tunnels during excavation. The study considered six cover-to-diameter (C/D) ratios, ten pillar-to-diameter (P/D) ratios, and two construction sequences. The total settlement of the excavated twin tunnels and the settlement induced solely by the new second tunnel were analyzed. Validation was performed by comparing results with published case studies, showing trends consistent with existing literature. Key findings include: (1) greater cover depth produces a wider settlement trough and reduces second tunnel-induced settlement, though total settlement slightly increases; (2) cover depth significantly affects second tunnel-induced settlement, while pillar width impacts total settlement; (3) concurrent excavation causes slightly higher settlement and a deeper, wider trough compared to staggered excavation; (4) lower cover depths result in higher settlement increase rates. Finally, two design charts are proposed to estimate settlement from the second tunnel and the eccentricity of the maximum total settlement relative to the center of the new tunnel.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106509"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512152","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":"Analysis on time-frequency characteristics and construction response of microseismic events on high and steep rock slopes: A case study of Dongzhuang Water Conservancy Project","authors":"Ke Ma ,&nbsp;Haiyang Liu ,&nbsp;Kaikai Wang ,&nbsp;Di Wu","doi":"10.1016/j.tust.2025.106499","DOIUrl":"10.1016/j.tust.2025.106499","url":null,"abstract":"<div><div>The right bank slope of the Dongzhuang Water Conservancy Project is steep and high, with numerous dissolution cavities and mud-filled cracks forming reasonably well in the solid limestone, complicating the geological conditions and emphasizing the slope stability issue. To clarify the activation characteristics of various weak structural planes in the rock mass of the right bank slope under the influence of geological defect treatment and high-pressure grouting disturbance and to evaluate the overall stability of the slope, a real-time monitoring system for micro-seismic activity in both the deep and shallow parts of the slope rock mass was used, combining core drilling and colored borehole television technology. A generalized β wavelet high-resolution time-frequency transformation algorithm was used to analyze the dynamic micro-seismic response and damage characteristics of the slope rock mass under different engineering disturbances. The results reveal that: (1) The rock mass on the right bank slope deteriorates as a result of limestone breakdown and local mineral infill, while its plastic properties improve. Microseismic events have an amplitude of 0.06 mV and low energy, and their frequency is primarily focused between 100 and 300 Hz, with low-frequency vibrations dominating. (2) During drilling disruption, the micro-fractures on both sides and the deeper areas of the Rnj3 dissolution-mud-filled fracture become much stronger than before drilling. The lateral fracture surface of the Rnj3 dissolution-mud-filled fracture and the bottom slip surface of the L61 fracture have a weak temporal and spatial link during micro-crack development, and the energy release level is low. As the microseismic activity of the downstream L61 fracture reduces, the prospective sliding body’s slip risk is reduced. (3) During the early grouting stage, the high-pressure slurry washed out the muck from the mud-filled fracture. This caused localized dislocation instability of the neighboring rock mass, resulting in micro-seismic event clusters scattered along the fracture zone. After grouting, there were fewer micro-seismic events at an elevation at a height at the Rnj3 mud-filled crack, indicating low rock mass activity. By the middle of grouting, the formation of microseismic events has stopped, and the surrounding rock was stable under the consolidating impact of the grout. The findings serve as a key guide for curtain grouting reinforcement of steep slopes and other comparable projects.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106499"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510745","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 tunneling speed enhancement method for super-large-diameter shield machines considering strata heterogeneity","authors":"Jian Zhang ,&nbsp;Jinjian Hu ,&nbsp;Chaoyang Zong ,&nbsp;Tugen Feng ,&nbsp;Tao Xu","doi":"10.1016/j.tust.2025.106496","DOIUrl":"10.1016/j.tust.2025.106496","url":null,"abstract":"<div><div>The geological environments faced by super-large-diameter shields are more complex than those encountered by regular-diameter shields. Incorrectly set excavation parameters can lead to increased construction costs and even serious engineering accidents. To ensure safe and efficient excavation processes for shield machines in complex strata, in this paper, which is based on the super-large-diameter shield project of the Jiangyin–Jingjiang Yangtze River Tunnel, a method for proportionally restoring the heterogeneous characteristics of composite strata, which is named the “tunnel face color image” method, is proposed for the first time. Utilizing machine learning and the grey wolf optimizer, models for predicting the tunneling speed and constrained items of the shield machine are established. On this basis, an improved grey wolf optimizer is further developed to construct an adaptive decision-making system for setting the main control parameters of the shield with the objective of maximizing the tunneling speed while satisfying the constraints imposed on the cutterhead torque and attitude deviations. The results show that the tunnel face color image method can effectively extract geological information from each shield cycle and use it as an input for the prediction model, resulting in an average absolute error of 0.916 mm/min for the most important tunneling speed prediction result and a determination coefficient of 0.879, thus outperforming other geological parameter processing methods. The adaptive decision-making system for setting the main control parameters of the shield, which is based on the improved grey wolf optimizer, is capable of accurately solving for the optimal operating parameters for each shield cycle with an optimization time that is shorter than those of the particle swarm optimization algorithm, genetic algorithm, and artificial fish swarm algorithm. Moreover, according to the optimal operating parameters obtained, the average tunneling speed in each ring of the shield can be increased by 39.9 % while reducing the fluctuation range of the cutterhead torque and making the attitude deviations more convergent.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106496"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510206","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":"An innovative non-destructive approach for the shrinkage assessment in two-component grout application","authors":"Aarathy Ezhuthupally Reghuprasad,&nbsp;Carmine Todaro,&nbsp;Francesca Pace,&nbsp;Daniele Peila,&nbsp;Alberto Godio","doi":"10.1016/j.tust.2025.106424","DOIUrl":"10.1016/j.tust.2025.106424","url":null,"abstract":"<div><div>In this study, a well-known technology known as the Fiber Bragg Grating (FBG) has been employed for the first time for the study of the two-component grout (2CG), the most used material for the backfilling phase in mechanised tunnelling. Using FBG, it has been possible to monitor both the temperature and the shrinkage of the 2CG since the first moments after the gelation of the grout. The procedure proposed and the outcomes presented in terms of shrinkage put alight the validity of the proposed approach, and the crucial importance of the curing environment. For a fixed mix design, values of shrinkage lower than 500 με have been founded after 16 days of curing in water irrespective of the tested bentonite, while in dry environment the shrinkage reached values higher than 3000 με.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106424"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510744","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":"Efficiency of pile barriers to mitigate supported excavation effects on existing tunnels","authors":"Xu He,&nbsp;Changqun Zuo,&nbsp;Xuedong Luo","doi":"10.1016/j.tust.2025.106447","DOIUrl":"10.1016/j.tust.2025.106447","url":null,"abstract":"<div><div>This paper shows a numerical study to evaluate the efficiency of different schemes of pile row barriers to mitigate the risk due to a deep excavation in soft soils adjacent to an existing tunnel, then use numerical analyses to understand the main mechanisms of excavation-barrier-tunnel interaction. Three-dimensional FDM analysis was conducted on deep-covered and shallow-covered tunnels with different support structures, including pile barrier, twin retaining wall, anchor-pile barrier supporting structure, along with monitoring data from a case history in Wuhan, the Huazhong Science and Technology Park basement. The monitoring data show successful excavation and basement construction within allowable displacement thresholds in the presence of the barrier. Numerical results indicate that the twin retaining wall can effectively control lateral displacements of front and rear rows, leading to a substantial reduction in ground surface movements, thus, there is a great percentage reduction in horizontal displacements and settlement of the existing tunnel. While pile barriers with prestressed anchor cables show greater control over settlement than horizontal displacement of the shallow-covered tunnel. The results of the analyses permit to recognise the efficiency and mechanism of different protective barrier schemes, providing some guidance for a rational design of the intervention.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106447"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510201","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":"Theoretical study on the soil additional stress and principal stress axis deflection during shield tunneling","authors":"Chen-Yang He ,&nbsp;Hai-Yang Zheng ,&nbsp;Zhi Ding ,&nbsp;Feng Huang","doi":"10.1016/j.tust.2025.106511","DOIUrl":"10.1016/j.tust.2025.106511","url":null,"abstract":"<div><div>Shield tunneling inevitably disturbs the surrounding soil, primarily resulting in changes in stress state, stress path, and strain. Modifications to certain parameters, such as shield thrust, shield friction, and soil loss, are made based on the elastic mechanics Mindlin solution and the mirror method, and a calculation expression for additional soil stresses induced by tunneling was derived. Additional soil stresses are calculated using the parameters of the Hangzhou Metro Kanji section. 3D principal stress paths and deviations of the principal stress axes near the tunnel crown, waist, and invert during shield tunneling were obtained by applying a transition matrix orthogonal transformation. These results are compared with experimental data to validate the theoretical solution’s accuracy. The stress distribution along the tunneling direction and the 3D principal stress paths and deviations of the principal stress axes in the surrounding soil are determined. The results are as follows: The additional soil stresses along the tunneling direction follow a normal distribution and an S-shape. Under the combined influence of three construction mechanics factors, the shear stress component is approximately 1/3 to 1/2 of the normal stress and should not be neglected. During shield tunneling, the deviation angle of the principal stress axis at the tunnel crown changes from 90° to 180°, with little change in the magnitude of the principal stress. At the invert, the magnitude of the principal stress rapidly increases from 0.25 kPa to 8 kPa, with minimal deviation in the principal stress axis. At the shoulder, the principal stress variation and axis deviation are small. At the foot of the arch, the deviation angle of the major and minor principal stress axes is larger, while the magnitude of the principal stress slightly changes. At the waist, the deviation angle of the major principal stress is larger, and the magnitude of the minor principal stress significantly changes. A strategy for addressing changes in soil stress paths during shield tunnel construction is also proposed.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106511"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510205","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 hydro-mechanical coupled method for assessing the influence of localised leakage at gasketed joints on the long-term behaviour of shield tunnels","authors":"Jiachong Xie ,&nbsp;Climent Molins ,&nbsp;Xin Huang","doi":"10.1016/j.tust.2025.106492","DOIUrl":"10.1016/j.tust.2025.106492","url":null,"abstract":"<div><div>Leakage defects at gasketed joints primarily induced by joint deformation and gasket ageing pose a significant challenge to the long-term safety of shield tunnels, leading to ground consolidation and structural deterioration of tunnel lining. A novel FEM analysis method was proposed to model the hydro-mechanical coupled behaviour of the joint during the long term, comprehensively incorporating a waterproof capacity degradation model, localised leakage behaviour characterised by cubic law, and correlations between joint deformation and gasket compression. The model was then validated by a full-scale experiment on the structural behaviour and the image tunnel method on the seepage field. The influence of localised leakage on soil-tunnel interaction and the structural responses of lining over the entire service duration was assessed, considering the effects of joint deformation, double-pair gaskets, number of leakage joints, and internal water pressure. The proposed method captures the initial waterproof stage of 40 years, followed by waterproof failure and progressive hydraulic deterioration of the joint. The localised leakage leads to increases in the bending moment, long-term settlement and ovalisation deformation. The use of double-pair gaskets effectively improves the waterproof capacity of the joint, extending the waterproof stages and mitigating further hydraulic deterioration. Additionally, the leakage pattern changes with the adoption of double-pair gaskets. The influence of internal water pressure is twofold: it enlarges the joint eccentricity and opening, exacerbating the waterproof capacity degradation; however, it also counteracts groundwater infiltration by reducing the hydraulic gradient. Internal water pressure primarily reduces axial forces, while leakage is mainly responsible for changes in bending moments and lining deformation.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106492"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510202","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}