Tunnelling and Underground Space Technology最新文献

{"title":"Calculation method and application of discontinuous longitudinal deformation of shield tunnels considering variable stiffness of the ring joints","authors":"Yanbin Fu ,&nbsp;Ning Liang ,&nbsp;Yuehua Guo ,&nbsp;Xiangsheng Chen ,&nbsp;Ze Wu ,&nbsp;Gendi Yelv ,&nbsp;Xiaoping Li","doi":"10.1016/j.tust.2025.106592","DOIUrl":"10.1016/j.tust.2025.106592","url":null,"abstract":"<div><div>Shield tunnels are typical underground structures assembled from segmental rings and bolts. The relatively small stiffness of the ring joints compared to segmental rings can easily lead to the discontinuous deformation, and even damage or spalling of the segments, which poses a serious threat to safe tunnel operation. How to consider the discontinuous stiffness and deformation of longitudinal structure has become the core problem in tunnel calculation. In this paper, regarding the ring joint stiffness as special singularities in longitudinal structural stiffness, a physical and mechanical model which can consider the discontinuities of longitudinal structural stiffness and deformation is proposed. Variable stiffness and discontinuous deformation of longitudinal structure is considered by Delta and Heaviside function. The analytical solutions of discontinuous deformation of the segmental rings and the ring joints are obtained by using normalized functions. The case analysis shows that proposed method is in good agreement with measured field data and the error of maximum settlement is 5%. The deformation peak is smaller than that of Timoshenko beam model, but the internal force peak is larger than that of Timoshenko beam model. The jump phenomenon of longitudinal deformation can be better described. Deformation and bending stiffness of the ring joints are highly coupled. With the increase of longitudinal differential settlement, the attenuation of ring joint bending stiffness will go through four stages: constant stiffness stage, sharp attenuation stage, stable attenuation stage and decelerated attenuation stage. Proposed analytical solution can solve the difficulties of calculating discontinuous longitudinal structure of shield tunnels, and provide theoretical reference for the evaluation of running subway tunnel.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106592"},"PeriodicalIF":6.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683871","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 specific energy and penetration interaction-based method for optimizing TBM operational parameters in hard rock","authors":"Lei She ,&nbsp;Cheng-cheng Hu ,&nbsp;Yan-long Li ,&nbsp;Dong-feng Li ,&nbsp;Zhao-Yu Li ,&nbsp;Tao Fang ,&nbsp;Ji-guang Zheng","doi":"10.1016/j.tust.2025.106585","DOIUrl":"10.1016/j.tust.2025.106585","url":null,"abstract":"<div><div>The timely and appropriate adjustment of operational parameters is necessary for efficient tunneling and hazard prevention in TBM projects. However, the currently provided operation control strategies mainly tend to adjust the operational parameters by TBM driver to achieve the maximum penetration, which leads to severe cutter wear in hard rock tunnels. This study innovatively uses tunnel specific energy (<em>SE</em>_TBM) to quantitatively describe the wear state of cutting tools, and proposes a quantitative optimization strategy for operating parameters based on the specific energy and penetration (<em>SE</em>_TBM-<em>P</em>) interaction relationship. A comprehensive database of TBM performance containing 219 tunnel intervals was compiled based on five tunnel projects from China, which covered the rock properties, TBM specifications and operational parameters necessary for performance optimization. The mapping relationship between tunnel specific energy and penetration for different rock types and rock mass properties was investigated in detail, and a standardized field penetration index (SFPI) characterizing only the rock mass properties was proposed. Subsequently, a new empirical prediction model for normalized disc cutter thrust was developed using the SFPI. Based on this, a parameter optimization procedure based on <em>SE</em>_TBM-<em>P</em> interaction diagram is constructed by taking into account various operational constraints of cutter load capacity, cutterhead torque limitation, and cutter assembly geometry restriction. It can maximize advance rate and minimize downtime under the influence of different RPMs of TBM. Finally, the proposed parameter optimization method is implemented in two recent tunnel projects to verify its effectiveness. This method can overcome the TBM drivers’ subjectivity and provide a quantitative prediction for the optimum tunneling strategy in hard rock TBM.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106585"},"PeriodicalIF":6.7,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683982","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":"Analytical study on the backfill grouting in mitigation of vibrations from a tunnel embedded in a half-space","authors":"Fan Li,&nbsp;Hui Wang,&nbsp;Yingyi Wang,&nbsp;Chong Li,&nbsp;Qing Ai,&nbsp;Xingchun Huang","doi":"10.1016/j.tust.2025.106587","DOIUrl":"10.1016/j.tust.2025.106587","url":null,"abstract":"<div><div>Ground vibrations from operating railway in tunnels is a significant obstacle to sustainable development of subway. The backfill grouting layer, formed during shield tunneling, serves as a critical medium in propagation of tunnel vibrations, highlighting its potential in vibration mitigation. A semi-analytical model for the tunnel-grouting layer-soil system is proposed in this study, in order to clarify the influence of backfill grouting layer on the dynamic responses in a half-space, subjected to tunnel vibrations. In establishment of the closed-form solution, the tunnel and grouting layer are considered as two nested hollow cylinders embedded in a half-space, with applying the Fourier transform and wave transformation. As a validation, the numerical results from the proposed semi-analytical model are compared with those reported in literature. Parametric studies, with respect to the geometric configuration (i.e., the thickness) and material parameters (i.e., the Young’s modulus, material damping, and density) of the backfill grouting layer in the mitigation of tunnel vibrations, are carried out. It is found that incorporation of the backfill grouting layer significantly changes the dynamic responses of the soil and, by appropriately designing its material parameters, especially the Young’s modulus, effective mitigation of tunnel vibrations can be achieved.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106587"},"PeriodicalIF":6.7,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683981","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":"Shaking table and pushover tests on subway station improved by truncated columns","authors":"Chao Ma ,&nbsp;Hao Wang ,&nbsp;De-chun Lu ,&nbsp;Guo-sheng Wang ,&nbsp;Guo-bo Wang","doi":"10.1016/j.tust.2025.106588","DOIUrl":"10.1016/j.tust.2025.106588","url":null,"abstract":"<div><div>Previous studies have demonstrated that reducing earthquake-induced damage to central columns in underground structures can effectively prevent the collapse of overall structures. Truncated columns (TC) are less likely to experience severe damage during lateral deformation because the partial release of the constraints at both ends of the columns helps maintain their integrity. This approach can effectively enhance the seismic performance of the overall underground structures. In this study, pushover and shaking table tests were conducted to investigate the seismic performance of a subway station using TC columns compared to that using the cast-in-place columns (CC). These tests aimed to examine failure modes, structural stiffness, lateral deformation and load-bearing capacities, acceleration and deformation responses of the underground structures. The results from the pushover tests indicated that the initial stiffness of both structures-those with TC and with CC-was equivalent. On the other hand, the shaking table tests showed no significant differences in the dynamic responses of the two types of underground structures under small earthquakes. However, the vertical ground motions exacerbated damage to the structures. Although the lateral load-bearing capacity of the structure with TC is somewhat lower, the movements between the column ends and beams during loading enhance the structure’s ability to adapt to the deformation of surrounding soil due to the release of column end constraints. As a result, the seismic resistance of the overall underground structures is improved. It is important to note that the ceiling slab and sidewalls in the structures with TC are more likely to crack during earthquakes, thus requiring additional efforts to prevent leakage. The findings of this study provide experimental evidence that supports the seismic control of underground structures.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106588"},"PeriodicalIF":6.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672846","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":"Multi-parameter determination method for rock discontinuity roughness based on geometric properties intelligent extraction","authors":"Furui Dong ,&nbsp;Shuhong Wang ,&nbsp;Hong Yin ,&nbsp;Seokwon Jeon","doi":"10.1016/j.tust.2025.106547","DOIUrl":"10.1016/j.tust.2025.106547","url":null,"abstract":"<div><div>To accurately and efficiently determine the rock joint roughness coefficient (<em>JRC</em>), a multi-parameter determination method for rock discontinuity roughness based on intelligent extraction of geometric properties was proposed. Firstly, a morphological characterization analysis program for rock discontinuities based on 3D point cloud reconstruction was developed. This program achieved the automatic extraction of arbitrary 2D profile lines and accurate calculation of multiple 2D characterization parameters. Then, two comprehensive characterization parameters were extracted from eight commonly used roughness characterization parameters by principal component analysis method. A multi-parameter determination method for rock discontinuity roughness based on the adaptive vigilance chaotic sparrow search algorithm optimizing extreme limit learning machine (ACSSA-ELM) was established to construct a nonlinear mapping relationship between the comprehensive characterization parameters and <em>JRC</em> to achieve an accurate prediction of discontinuity roughness. The proposed method’s performance was validated using 112 2D profile samples and three granite discontinuity samples, and the reliability of the method was demonstrated by comparing it with other methods. The sensitivity of the method to sampling interval, anisotropy, and sampling size was discussed. Finally, the proposed method was applied to the construction of the Xinglong tunnel, providing effective guidance for practical construction activities.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106547"},"PeriodicalIF":6.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672848","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 and numerical research of hydrogen-blended natural gas leakage and diffusion in utility tunnels","authors":"Xiwen Chang ,&nbsp;Minghao Li ,&nbsp;Hui Han ,&nbsp;Pengfei Duan ,&nbsp;Yingying Kong ,&nbsp;Zikang Qin ,&nbsp;Jianlu Zhu ,&nbsp;Yuxing Li","doi":"10.1016/j.tust.2025.106578","DOIUrl":"10.1016/j.tust.2025.106578","url":null,"abstract":"<div><div>The safety of hydrogen-blended natural gas (HBNG) in underground utility tunnels continues to receive attention. In this study, an experiment platform for the leakage near-field of the utility tunnel is designed based on the similarity theory. The reliability of CFD numerical simulation in the leakage near field is verified by experiments. For the leakage process of HBNG, the increase of hydrogen blending ratio (HBR) enhances the diffusion in the horizontal direction. The gas concentration in the measurement points tend to a maximum value with increasing leakage time during the leakage process in the ventilated condition. The study carried out CFD numerical simulations of HBNG leakage in the entire utility tunnel. It was found that some changes in leak location do not affect the stabilized concentration during ventilation. The alarm time is linearly related to the horizontal distance of the alarm from the leak source. Based on the numerical simulation results, a simple model of HBR, alarm location and alarm trigger time was obtained. The model can provide some references for the location and number of alarms in the utility tunnel.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106578"},"PeriodicalIF":6.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672847","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":"The experimental study on the flame extension length and maximum temperature of ceiling jet flame in the curved tunnel","authors":"Yang Gao ,&nbsp;Yuhao Fang ,&nbsp;Lunlun Gong ,&nbsp;Shenlin Yang ,&nbsp;Changfa Tao ,&nbsp;Wei Xu","doi":"10.1016/j.tust.2025.106571","DOIUrl":"10.1016/j.tust.2025.106571","url":null,"abstract":"<div><div>This paper investigated the extension length and maximum temperature of ceiling jet flame with different fire source locations within the curved tunnel. A series of experiments were conducted in a 1:15 reduced-scale tunnel with four different bending radians. Two nozzle diameters (2 and 4 mm) and four fire source positions were considered, while the propane was used as the fuel gas. The experimental results reveal distinct extension characteristics of ceiling jet flame in both the transverse and longitudinal directions. Dimensionless correlations for the transverse and longitudinal extension length of ceiling jet flame have been developed. Additionally, the variation in maximum temperature under different tunnel bending radians was analyzed based on the flame geometry model, which leads to the establishment of theoretical model for predicting the maximum temperature.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106571"},"PeriodicalIF":6.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632068","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 of longitudinal deformation of existing rectangular pipe jacking tunnel caused by shield tunnel undercrossing","authors":"Youjun Xu ,&nbsp;Zhengxi Zhang ,&nbsp;Chao Zhang ,&nbsp;Xin Han ,&nbsp;Tianyu Liu ,&nbsp;Xu Zhang","doi":"10.1016/j.tust.2025.106532","DOIUrl":"10.1016/j.tust.2025.106532","url":null,"abstract":"<div><div>The existing rectangular pipe jacking tunnel is prone to deform after the construction of the new nearby shield tunnel, resulting in longitudinal uneven settlement, water leakage, and other ailments that could jeopardize the structure’s safety. The safety of the existing rectangular pipe jacking tunnel is in jeopardy in order to prevent the excessive deformation of the tunnel following the construction of the new shield tunnel. This paper proposes the foundation stiffness function model and SP-T model to describe the settlement curve of the new shield tunnel to the existing rectangular pipe jacking tunnel using the first phase project of Hohhot Rail Transit Line 2 in Inner Mongolia as an example. The model is more coincidental than the original Pasternak-Timoshenko model considering the distribution in soil caused by the excavation of a new tunnel because it takes into account the change in foundation stiffness based on the Pasternak foundation. The findings demonstrate the consistency between the field data results and the prediction results derived from the analysis method presented in this paper. The further parametric study examined some influences on the construction of a new shield tunnel that affects already-existing pipe jacking tunnels. These studies include equivalent longitudinal bending and shear stiffness, as well as the location and angle of the new tunnel in relation to the existing rectangular pipe jacking tunnel. In addition to highlighting the impact of equivalent shear stiffness on the existing rectangular pipe jacking tunnel, the impact of equivalent longitudinal bending stiffness and equivalent longitudinal shear stiffness on settlement is discussed in the article.<!--> <!-->This paper’s research methodology can not only forecast the new shield tunnel’s longitudinal settlement deformation beneath the existing rectangular pipe jacking tunnel, but it can also generate fresh concepts for investigating related issues.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106532"},"PeriodicalIF":6.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632067","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 and numerical study of the failure mechanism and minimum safety thickness of water-resistant rock mass in layered karst tunnels","authors":"Qianfeng Xiao,&nbsp;Yang Wang,&nbsp;Yajing Li,&nbsp;Leilei Jin,&nbsp;Wenxi Fu,&nbsp;Fei Ye","doi":"10.1016/j.tust.2025.106586","DOIUrl":"10.1016/j.tust.2025.106586","url":null,"abstract":"<div><div>Excavating layered karst tunnels often triggers water and mud inrushes, posing serious risks to life and property. This paper examines the effect of layered rock structures on the failure mechanism and minimum safety thickness of water-resistant rock mass. First, mechanical models for horizontally and vertically layered water-resistant rock mass are established. Utilizing the Mohr-Coulomb criterion and the minimum potential energy principle, analytical solutions for the minimum safety thickness of both models are derived. Next, the discrete element method (DEM) is used to analyze fracture propagation, force chain interactions, and displacement distribution in both horizontally and vertically layered water-resistant rock mass. Finally, based on theoretical and numerical analyses, failure modes of layered water-resistant rock mass with different strata inclinations are proposed: flexural-tensile failure in vertically layered rock, creep-sliding tensile failure in horizontally layered rock, and the combined toppling-bending tensile failure mode in inclined layered rock. The results indicate that (1) the variation curve of crack numbers in a water-resistant rock mass can be categorized into four distinct stages: Stage I, the fracture development and rock mass damage stage; Stage II, the fracture equilibrium and energy absorption stage; Stage III, the large deformation and rapid fracture progression stage; and Stage IV, the complete failure stage. (2) Shear failure occurs along the structural plane within the horizontally layered water-resistant rock mass. Tensile rupture failure occurs in the horizontally layered rock mass when the shear strength of the structural plane exceeds the tensile strength of the rock mass. (3) Bending failure occurs in the vertically layered water-resistant rock mass. The force chain within the rock mass at the tunnel face end undergoes tensile stress, whereas at the cavity end, the force chain is subjected to compressive stress.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106586"},"PeriodicalIF":6.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637594","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 internal rise law of fracture water pressure and progressive fracture mechanism of rock mass under blasting impact","authors":"Diyang Chen ,&nbsp;Yanhao Chen ,&nbsp;Zongqing Zhou ,&nbsp;Wenfeng Tu ,&nbsp;Liping Li","doi":"10.1016/j.tust.2025.106545","DOIUrl":"10.1016/j.tust.2025.106545","url":null,"abstract":"<div><div>Groundwater and its storage structures are widespread, leading to frequent water inrush disasters during tunnel construction, which severely compromise safety and efficiency. Blasting disturbances cause rock fissures to expand and connect, leading to instability and failure. However, the mechanisms behind tunnel water inrush caused by blasting, especially the dynamic changes in water pressure within fissures, remain insufficiently understood. This study addresses water inrush caused by fractured rock mass failure under dynamic disturbance, focusing on deep, high-pressure tunnels with complex geological conditions. It systematically explores how blasting impacts water pressure in fissures, using safe and efficient simulation methods combined with dynamic damage tests on water-bearing fractures. The research examines how blasting-induced water pressure changes affect rock stability. The findings reveal that the increase in water pressure caused by blasting provides a theoretical basis for understanding water inrush mechanisms and disaster criteria. Additionally, this study overcomes the limitations of traditional explosive tests by achieving safe, controlled, and efficient blasting simulations. It advances the analysis of water-bearing fractures from qualitative to quantitative characterization, offering new insights and methods for preventing water inrush disasters during tunnel construction.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"161 ","pages":"Article 106545"},"PeriodicalIF":6.7,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632065","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}