Tunnelling and Underground Space Technology最新文献

{"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}

{"title":"Rock mass instability early warning model: A case study of a high and steep annular slope mining areas using Sen’s slope trend analysis","authors":"Jiachuang Wang,&nbsp;Longjun Dong,&nbsp;Shengyu Ji","doi":"10.1016/j.tust.2025.106514","DOIUrl":"10.1016/j.tust.2025.106514","url":null,"abstract":"<div><div>As mineral resources continue to be developed, the risk of rock mass instability from deep mining has gradually increased, particularly in high and steep annular slope mining areas, where hazards such as landslides and rock collapses are more prevalent. Consequently, establishing a reliable and early warning model is crucial. This study proposes a multi-index fusion early warning model for rock mass instability based on Sen’s slope trend analysis. First, the microseismic activity patterns and source parameters of a gold mine in northwest China were analyzed. Using a rock mass instability event as a case study, the cumulative Benioff strain, <em>b</em>-value, <em>S</em>-value, energy index, cumulative apparent volume, and Hurst exponent were selected to explore the change patterns of these indicators before the event. Next, the trends of these indicators were analyzed using a sliding time window and Sen’s slope method, and the correlation between the event occurrence (target variable) and indicator values (characteristic variables) was calculated, leading to the development of a rock mass instability warning method and multi-index fusion rock mass instability warning index, the <em>Q</em>-value. Finally, the model generated a visual cloud chart for real-time monitoring of <em>Q</em>-value changes across different areas. By observing the trend of early warning index changes over time or space, potential danger zones can be effectively predicted. Results show that the early warning model based on Sen’s slope trend analysis is highly effective in providing early warnings for rock mass instability in high and steep annular slope mining areas. The proposed warning model offers valuable technical support for mine managers, enabling stratified management strategies and ensuring safe mine operations.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106514"},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510200","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 the instability mode of a tunnel face under variable seepage conditions in sandy soil shield tunnels: Centrifuge tests and numerical simulation","authors":"Xiaolin Weng ,&nbsp;Bohan Dang ,&nbsp;Xuancong Li ,&nbsp;Fei Ye ,&nbsp;Yangchen Ma","doi":"10.1016/j.tust.2025.106515","DOIUrl":"10.1016/j.tust.2025.106515","url":null,"abstract":"<div><div>Shield tunnel excavation in water-rich sandy soil experiences rapid seepage variations at the tunnel face due to groundwater level fluctuations. To study the instability mode of the tunnel face in water-rich sandy soil under variable seepage conditions, taking a metro construction project as the engineering background, a set of tunnel face instability devices including a water level control system suitable for a geotechnical centrifuge were independently developed. Centrifuge model tests were conducted using the self-designed model device. The displacement field, earth pressure, and pore pressure in the instability zone were automatically measured during the experiments. Complementary numerical simulations were conducted to analyze the limit support pressure at the tunnel face under variable seepage conditions. Results show that under variable seepage conditions, the instability zone of the tunnel face in a sandy soil shield tunnel exhibits a “wedge + prism + iterative arch” type and displays an angle of approximately 45° + <em>φ</em>/2 (where <em>φ</em> represents the friction angle of the soil) between the inclined plane of the wedge and the horizontal direction. The top of the final instability zone extends to the surface to form a “chimney” shape. During the instability process, the earth pressure within the instability zone is continuously decreased, the displacement of the strata leads to an increase in the seepage channels, and the pore pressure increases. The changes in the earth and pore pressures become more pronounced when approaching the tunnel face. The increase in seepage intensity accelerates the development of the instability zone and increases the changes in the earth and pore pressures. The stability of the strata in the instability zone decreases rapidly with increasing seepage intensity. The limit support pressure at is primarily governed by the initial groundwater level and the rate of seepage intensity variation.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106515"},"PeriodicalIF":6.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488724","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":"FDEM numerical study on the large deformation mechanism of layered rock mass tunnel under excavation-unloading disturbance","authors":"Ping Liu ,&nbsp;Hongtao Wang ,&nbsp;Quansheng Liu ,&nbsp;Xiaojing Li ,&nbsp;Yuanxuan Dong ,&nbsp;Xianqi Xie","doi":"10.1016/j.tust.2025.106497","DOIUrl":"10.1016/j.tust.2025.106497","url":null,"abstract":"<div><div>During tunnel excavation, the unloading effect leads to a weakening of the mechanical properties of the rock mass, with mechanical parameters exhibiting dynamic variations throughout the unloading process. Therefore, the dynamic evolution of mechanical parameters is a crucial aspect that must be considered in numerical simulations. Through unloading mechanical tests on the slate, this study establishes a quantitative linear relationship model between unloading and changes in deformation modulus and cohesion and further extends this model to tensile strength parameters. Using a horizontally stratified slate tunnel excavation as an example, numerical simulations were conducted to examine the large deformation, fracturing, and swelling process of layered rock masses under the deterioration of cohesion, tensile strength, and deformation modulus. The results show that the weakening of the deformation modulus due to unloading has a minimal impact on rock mass response, while the degradation of cohesion and tensile strength is the critical factor causing large deformations in tunnels. Additionally, as the deterioration of cohesion and tensile strength intensifies, the extent of fracturing and the range of the highly damaged zone in the rock mass significantly increase. The Muzhailing Tunnel project case study verifies the reliability of the proposed FDEM method, which incorporates the effects of unloading-induced weakening, and demonstrates the necessity of accounting for the degradation of mechanical parameters in FDEM simulations.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106497"},"PeriodicalIF":6.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488762","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":"Graffiti in pedestrian tunnels: A comparison of police records and crowdsourced data in Stockholm, Sweden","authors":"Vania Ceccato ,&nbsp;Ioannis Ioannidis ,&nbsp;Marcus Felson","doi":"10.1016/j.tust.2025.106482","DOIUrl":"10.1016/j.tust.2025.106482","url":null,"abstract":"<div><div>Using 1281 pedestrian tunnels scattered over Stockholm, Sweden’s capital, we investigate the nature and distribution of graffiti in three types of underpasses (pathways, cycleways, and stairways). Combining crowdsourced data and police records, we compare graffiti levels and geography using fieldwork inspections, regression models, and Geographic Information Systems (GIS). The findings indicate that graffiti recorded to the police is present in only a quarter of the pedestrian tunnels, suggesting that recorded practices are concentrated in specific underpasses. Graffiti is more commonly found in larger tunnels, particularly cycling underpasses. Proximity to metro stations, schools, and the presence of young males in the area are factors linked to graffiti occurrence, although not consistently. These results highlight the complexities of relying on graffiti records for public space management, particularly the challenges professionals face in aligning the maintenance of pedestrian tunnels with urban sustainability goals.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106482"},"PeriodicalIF":6.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488725","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":"Optimizing the cooling method and parameters for high geothermal tunnel construction by using model experiment","authors":"Heng Zhang ,&nbsp;Bo Wang ,&nbsp;Yiqi Zhao ,&nbsp;Zelin Zhou ,&nbsp;Xinrong Tan ,&nbsp;Long Xiang ,&nbsp;Yi Feng","doi":"10.1016/j.tust.2025.106495","DOIUrl":"10.1016/j.tust.2025.106495","url":null,"abstract":"<div><div>High temperature environment during tunnel construction not only causes concrete cracking in the lining structure, but also poses a threat to the safety and health of on-site workers. This paper aims to study the cooling measures and effects of high-temperature tunnel construction environment, explore its characteristics and determine the design parameters. Based on 1:8 scaled model testing platform, the influence of key ventilation parameters on the temperature drop characteristics of tunnels was first studied. Meanwhile, the change of flow rate and injection angle on the temperature field in the tunnel during the spray cooling measures is analyzed. The results show that the wind speed mainly affects the starting cooling moment of each tunnel section, the wind temperature mainly affects the cooling efficiency of the tunnel section. Due to the fact that the evaporation process of fog droplets mainly occurs behind the nozzle, the tunnel area located behind the nozzle position is greatly affected by flow rate changes.The cooling efficiency is ranked from high to low as follows: the tunnel drainage area behind the nozzle &gt; the tunnel drainage area before the air duct outlet &gt; the tunnel drainage area between the two positions.For areas close to the working face, the cooling efficiency increases with the increase of spray angle, while for sections far from the working face, the cooling efficiency decreases with the increase of spray angle.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"159 ","pages":"Article 106495"},"PeriodicalIF":6.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488763","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}