Tunnelling and Underground Space Technology最新文献

{"title":"A novel in-situ tunnel expansion method based on removable prestressed active support technology for rapid construction","authors":"Xingyuan Cheng ,&nbsp;Bo Wang ,&nbsp;Xinxin Guo ,&nbsp;Luo Zhang","doi":"10.1016/j.tust.2025.107155","DOIUrl":"10.1016/j.tust.2025.107155","url":null,"abstract":"<div><div>With the continuous increase in vehicle ownership and travel demand, the need for in-situ expansion of existing tunnels has grown annually. However, current expansion methods are predominantly confined to the traditional approach of ‘initial backfilling followed by sequential excavation with temporary supports.’ While these methods effectively control surrounding rock deformation, they suffer from complicated construction procedures, limited workspace, operational complexity, and high costs. To address this, this paper proposes a novel in-situ tunnel expansion method based on removable prestressed active support technology (hereinafter referred to as the novel method). The novel method employs removable prestressed anchor as the primary supporting components, with active pre-support as its core design principle. By replacing traditional ‘inner lining’ structures with an ‘outward pulling’ mechanism, it fundamentally overturns the traditional construction approach, eliminating the need for backfilling and temporary supports. Compared to current expansion methods, the novel method offers advantages including streamlined construction procedures, high efficiency, superior economic viability, and ample construction space. A case study on Tangling Tunnel validates this method through a removable scheme. Numerical simulations were conducted to compare this scheme with the original design. The key findings are as follows: (1) both schemes exhibit comparable performance in controlling surrounding rock deformation; (2) the removable scheme reduces the plastic zone volume above the invert arch and support structure stresses by over 20%; (3) it also reduces cost by 17,867 CNY per meter and shortens construction time by 10 hours per meter. Aligning with contemporary principles of green, low-carbon, and sustainable development, the novel method exhibits substantial potential for in-situ tunnel expansion projects.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107155"},"PeriodicalIF":7.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic characteristics and crack propagation of cement-based lining composites under drill-blasting excavation in deep tunnel","authors":"Lingling Hu ,&nbsp;Yongsheng Jia ,&nbsp;Yingkang Yao ,&nbsp;Zhendong Leng","doi":"10.1016/j.tust.2025.107154","DOIUrl":"10.1016/j.tust.2025.107154","url":null,"abstract":"<div><div>Tunnel lining of deep-buried construction engineering in Southwest China faces major challenges due to sustained high geothermal temperature and early-stage blasting vibrations from drilling and blasting excavation. To uncover damage evolution of the affected tunnel linings, this study investigates the dynamic mechanical behavior and the crack propagation of cement-based lining composites with varying pre-curing temperatures. A combined SHPB and high-speed imaging system were employed to quantify strain-rate-dependent responses, while DIC and X-ray CT elucidated the real-time crack propagation and post-impact pore structure evolution. The results demonstrated temperature-dependent performance optimization: pre-curing at 40 °C led to a 39.9 % increase in 3-d static compressive strength compared to the 20 °C control, along with the highest dynamic compressive strength and a 7.6 % enhancement in dynamic splitting tensile strength. DIC analysis identified a three-stage propagation pattern for the crack evolution. These findings offer critical insights into optimizing structural durability of tunnel linings in high geothermal environments.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107154"},"PeriodicalIF":7.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261974","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":"Ground movement induced by tunnelling in shallow loess strata","authors":"Chaopeng Tian,&nbsp;Jianxun Chen,&nbsp;Yanbin Luo,&nbsp;Weiwei Liu,&nbsp;Yao Li,&nbsp;Lixin Zhang,&nbsp;Benxian Gao,&nbsp;Jinhang Li","doi":"10.1016/j.tust.2025.107156","DOIUrl":"10.1016/j.tust.2025.107156","url":null,"abstract":"<div><div>Ground movement frequently leads to disasters, including ground subsidence, damage to adjacent structures, and instability of surrounding rock, these failure modes critically challenge safety assurance in tunnel construction. This paper conducts a ground movement monitoring on the Luochuan Tunnel, systematically tracking surface settlement, layered settlement and horizontal displacement of deep soil, and support structure deformations during the construction of a shallow-buried large-span loess tunnel, and the mechanism of ground movement was explored and analyzed. Furthermore, integrated with numerical simulations, the characteristic patterns of ground movement influenced by surface load effects was investigated. The research findings indicate that the shape of the surface settlement trough exhibits a “narrow and steep” distribution, which transforms into a “wide and gentle” distribution under the influence of surface load, with the settlement value increasing from 187 mm to 303 mm. The deformation of the ground and supporting structure exhibits characteristics of minor horizontal movement and significant vertical movement. The layered settlement initially increases and then decreases with depth. The horizontal displacement along the tunnel axis experiences a process of rebounding deformation after increasing in the opposite direction of the tunnelling, and the horizontal displacement along the tunnel transverse converges towards the center. Under the influence of surface load, the ground movement increases, with a significant surge in the deformation rate during the construction of the middle and lower benches. The settlement rate of arch exceeds that of ground surface, and volume loss increases from 2.51 to 3.81 with depth. Under the influence of surface load and rainfall, differential settlement decreases from 142 mm to 3 mm, while volume loss increases to a range of 5.77 to 5.80, and the ground deformation mode shifts from progressive loosening to global settlement. Under the surface load coverage, the settlement contour of the ground exhibits a vertical profile, diminishing from the tunnel centrical line towards the periphery. The surrounding rock is primarily characterized by progressively expanding shear failures, with a tensile-shear composite failure occurring above the arch crown, and the failure range stabilizes within 15 m from the tunnel centrical line. These findings can contribute to effective deformation control in loess tunnels.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107156"},"PeriodicalIF":7.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261970","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":"Development of similar materials for typical coral reef limestone and stability analysis of tunnel excavation in soft-hard interbedded stratum","authors":"Xiangyu Zhang ,&nbsp;Lewen Zhang ,&nbsp;Jing Wu ,&nbsp;Jianxi Liu ,&nbsp;Yue Ding","doi":"10.1016/j.tust.2025.107158","DOIUrl":"10.1016/j.tust.2025.107158","url":null,"abstract":"<div><div>The development of underground space in island and reef environments is a key trend in marine engineering. This study aims to develop suitable similar materials for coral reef limestone (CRL) and analyze the stability of surrounding rock during the tunnel excavation. Firstly, using the quartz sand, barite powder, cement, gypsum powder, calcareous sand, coral sand, coral debris, and water as raw materials, four types of CRL similar materials are developed based on its mechanical parameters and the BP neural network inversion method. Secondly, physical model tests are conducted to assess displacement and stress variations during tunnel excavation in the CRL stratum and ordinary stratum, with a focus on the influence of CRL pore structure on the stability of the surrounding rock and deformation failure in the excavation zone. Finally, the numerical simulation of tunnel excavation is carried out to explore the overall impact of the CRL pore structure on the stability of the surrounding rock during tunnel excavation. Results show that: i) The developed materials satisfy the strength and structure characteristics of different types of CRL. ii) The presence of the CRL pore structure leads to a faster rate of rock displacement and stress change, with both the displacement and stress release rates being higher than those of the ordinary stratum. (iii) When tunnel excavation passes through the soft and hard interbedded CRL, the significant deformation occurred in the soft rock and compression failure is prone to occur at the interface between soft and hard rock. iv) The pore structure not only affects the strength of the rock mass but also makes the rock mass more prone to failure. This study provides important insights for underground engineering in marine environments.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107158"},"PeriodicalIF":7.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261973","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":"Seismic fragility assessment of an underground structure based on the experimental data from shaking table tests","authors":"Yangjuan Bao ,&nbsp;Hongqiang Hu ,&nbsp;Zhongkai Huang ,&nbsp;Zhiqian Liu","doi":"10.1016/j.tust.2025.107150","DOIUrl":"10.1016/j.tust.2025.107150","url":null,"abstract":"<div><div>Classical seismic fragility assessment of underground structures always develops fragility curves or surfaces by analytical approaches, which is based on a suite of numerical simulations. In this study, a novel approach for seismic fragility assessment of underground structures based on experimental data is proposed, in which optimal intensity measure (IM), fragility curves and surfaces of underground structures can be simultaneously obtained. A set of shaking table tests of a subway station structure are firstly carried out to provide experimental data for optimal IM identification and fragility function construction. The results indicate that the peak ground acceleration, peak ground velocity and acceleration spectrum intensity are potential optimal IMs for fragility assessment of the underground structure, because they have the most or second correlated, practical, efficient, and proficient parameter values. Then, different scalar fragility curves and vector fragility surfaces in terms of different limit states are obtained. Different fragility probability results can be inferred from different fragility curves that developed by various earthquake IMs. The results also demonstrate that vector fragility surfaces have ability to offer more complete and robust information for probabilistic seismic performance assessment of underground structures than scalar fragility curves. The proposed approach and the obtained results provide the basis for addressing the entire framework of seismic resilience assessment of underground structures.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107150"},"PeriodicalIF":7.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261993","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 on the load-bearing performance and interface stress of plastic pipe–CIPP liner composite Structures","authors":"Xuehao Wang ,&nbsp;Xuefeng Yan ,&nbsp;Samuel T. Ariaratnam ,&nbsp;Baosong Ma ,&nbsp;Yahong Zhao","doi":"10.1016/j.tust.2025.107160","DOIUrl":"10.1016/j.tust.2025.107160","url":null,"abstract":"<div><div>Flexible plastic pipes are widely deployed in urban drainage networks, yet aging and construction irregularities lead to corrosion, leakage, deformation, and joint failures. Cured-in-Place Pipe (CIPP) rehabilitation installs a resin-cured liner inside the host pipe to form a composite system, whose mechanics for plastic hosts remain insufficiently quantified. This study integrates OFDR-based distributed strain sensing, parallel-plate loading tests, and a validated 3D finite-element model with a cohesive interface to interrogate the effects of the liner-to-pipe thickness ratio <span><math><mrow><mi>β</mi></mrow></math></span>, pipe diameter <span><math><mrow><mi>D</mi></mrow></math></span>, and modulus ratio <span><math><mrow><mi>η</mi><mo>=</mo><msub><mi>E</mi><mi>a</mi></msub><mo>/</mo><msub><mi>E</mi><mi>b</mi></msub></mrow></math></span> on ring stiffness, bending-moment sharing, and interfacial stresses. Results show that interfacial bonding is the key lever for composite action: ring stiffness was observed to increase monotonically with <span><math><mrow><mi>β</mi></mrow></math></span>, by ≈92 % and ≈210 % in the DN315 PE series relative to the<span><math><mrow><mi>β</mi></mrow></math></span> = 0.15 baseline, whereas non-bonded interfaces yield much lower stiffness. Neutral-axis migration with increasing <span><math><mrow><mi>β</mi></mrow></math></span> or <span><math><mrow><mi>η</mi></mrow></math></span> explains the measured strain patterns. At a fixed deformation, <span><math><mrow><mi>D</mi></mrow></math></span> mainly sets demand, while moment partition is governed by <span><math><mrow><mi>β</mi></mrow></math></span> and bonding. Coaction of interface shear with tensile radial stress at the crown/invert was identified as the primary driver for debonding, consistent with the closed-form and FE stress fields. Two simplified relations are proposed for ring-stiffness enhancement and bonding-induced moment amplification; predictions agree with tests and FE trends within the calibrated ranges <span><math><mrow><mi>β</mi><mo>∈</mo></mrow></math></span>[0.15, 0.70], <span><math><mrow><mi>η</mi><mo>∈</mo></mrow></math></span>[0.14, 0.47], and<span><math><mrow><mi>D</mi></mrow></math></span> = 250–500 mm. The findings provide design guidance for specifying liner thickness and verifying interfacial bonding in CIPP rehabilitation of plastic pipelines.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107160"},"PeriodicalIF":7.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261963","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":"Non-Darcy seepage analysis on subsea tunnel in fractured rock mass with grouting reinforcement","authors":"Lanxiang Zheng,&nbsp;Dingli Zhang,&nbsp;Zhenyu Sun,&nbsp;Song Lu,&nbsp;Yufan Du","doi":"10.1016/j.tust.2025.107115","DOIUrl":"10.1016/j.tust.2025.107115","url":null,"abstract":"<div><div>Grouting reinforcement is commonly employed in subsea tunnels. A thorough understanding of seepage behavior is vital for optimizing grouting design and evaluating its effectiveness. Previous studies employing Darcy’s law have been found inadequate for capturing the nonlinear seepage behavior under high hydraulic heads in subsea tunnels. Moreover, most analytical investigations on nonlinear seepage behavior have neglected the influence of non-circular cross-sections. Therefore, the non-Darcy seepage behavior in subsea tunnels constructed in fractured rock masses reinforced by grouting is investigated in this study. An analytical model featuring a non-circular cross-section and a grouting zone is developed based on the Izbash non-Darcy flow model using complex variable function theory and conformal mapping. Analytical solutions for water inflow and pore pressure that account for the presence of grouting zone in fractured rock masses are derived. The solutions are validated against numerical simulations results and field monitoring data from the Qingdao-Jiaozhou Bay Second Subsea Tunnel. Parametric studies are performed to quantify the influence of the Izbash empirical coefficient on the tunnel water inflow, pore pressure and hydraulic gradient. Furthermore, the effects on water-blocking performance of key grouting parameters, including the relative permeability coefficient and the thickness of grouting zone, are investigated under non-Darcy flow conditions. The results indicate that non-Darcy flow significantly affects water inflow, pore pressure and hydraulic gradient in subsea tunnels. An optimized design of the grouting zone is essential to ensure effective water-blocking performance, adequate mechanical strength, and economic feasibility. The proposed analytical model and methodology provide a theoretical foundation basis for the design of waterproofing and drainage systems in subsea tunnels in fractured rock masses.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107115"},"PeriodicalIF":7.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261965","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 deformation mechanism and application of trench cutting re-mixing deep walls","authors":"Peng Jiang,&nbsp;Shukun Zhang","doi":"10.1016/j.tust.2025.107157","DOIUrl":"10.1016/j.tust.2025.107157","url":null,"abstract":"<div><div>Trench cutting re-mixing deep walls can effectively mitigate water ingress and seepage; however, their low tensile strengths prevent them from serving as independent primary support structures for open-cut foundation pits. Therefore, they must be combined with concrete bored piles to form composite primary support systems. However, the wall stiffness can be effectively enhanced by replacing the concrete bored piles with H-section steel beams; this replacement results in an integrated wall–pile primary support structure. The deformation of the primary support structure is one of the key parameters of foundation-pit excavation. Using the elastic foundation-beam principle, mathematical expressions for the stress, bending moment, rotation angle, and horizontal displacement of the steel beams were derived for two boundary conditions: a scenario in which the top ends of the steel beams are free and a scenario in which the top ends are constrained by a capping beam. Using reasonable parameter assignments, the effects of both the active and passive earth pressures, the excavation depth, the steel-beam spacing, and the foundation-pit depth on the horizontal displacements of the steel beams were investigated.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107157"},"PeriodicalIF":7.4,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261964","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 comparative analysis of numerical approaches for hydrogen storage in salt cavern during injection-stand-withdrawal process with brine impact","authors":"Wanrui Hu ,&nbsp;Wenjing Li ,&nbsp;Tao Sun ,&nbsp;Chengyu Ma ,&nbsp;Xiuxiu Miao","doi":"10.1016/j.tust.2025.107159","DOIUrl":"10.1016/j.tust.2025.107159","url":null,"abstract":"<div><div>Underground salt caverns have been widely used for natural gas storage for decades. However, their suitability and applicability for hydrogen storage remains uncertain due to limited engineering experience.<!--> <!-->To assess the feasibility of salt caverns for hydrogen storage, a critical challenge lies in understanding the<!--> <!-->thermodynamic behavior of hydrogen under cyclic injection-and-withdrawal conditions.This study presents<!--> <!-->a coupled thermodynamic and thermomechanical model<!--> <!-->of a salt cavern, integrating the transport mechanism of cycling hydrogen and the surrounding wall of salt cavern. A comparative analysis of the<!--> <!-->thermodynamic properties of hydrogen and methane<!--> <!-->is conducted, and<!--> <!-->multiple operational scenarios<!--> <!-->are simulated to evaluate the effects of: initial temperature, injection/withdrawal rates, and heat transfer characteristics. Key findings reveal that<!--> <!-->higher storage pressures are required to maximize hydrogen capacitycompared to methane. As bottom brine occupies a large portion of storage volume, the<!--> <!-->impact of brine on hydrogen solubility<!--> <!-->is investigated based on the modified experiment correlation and thermomechanical model. The results of this study offer<!--> <!-->valuable guidance for the design and practical implementation of salt caverns as large-scale hydrogen storage systems, supporting the transition to sustainable energy solutions.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107159"},"PeriodicalIF":7.4,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261966","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 solution for shield tunnel structural behavior considering nonlinear shear stiffness of circumferential joint","authors":"Haolan Feng ,&nbsp;Dongming Zhang ,&nbsp;Hao Bai ,&nbsp;Yelu Zhou ,&nbsp;Hongwei Huang","doi":"10.1016/j.tust.2025.107138","DOIUrl":"10.1016/j.tust.2025.107138","url":null,"abstract":"<div><div>When analyzing the deformation and internal forces of shield tunnels subjected to external disturbances such as surface surcharge and nearby deep excavation, the assumption of linear or constant shear stiffness of segmental joints, commonly adopted in current design practices, cannot adequately capture the nonlinear degradation of shear stiffness with increasing circumferential joint dislocation. To address this limitation, this paper focuses on circumferential joints with oblique bolt connections and analyzes the nonlinear relationship between shear stiffness and joint dislocation of oblique bolts at various positions. The study then aggregates the shear stiffness of all oblique bolts and concrete segments to obtain the circumferential joint shear stiffness and determine the key parameters in the nonlinear expression. Taking surface surcharge as a case study, the deformation and internal forces of the shield tunnel are derived using a numerical solution based on the finite difference method, with results verified by a refined 3D finite element model. The results indicate that the nonlinear relationship between shear stiffness and circumferential joint dislocation can be represented by a logistic function with three parameters: initial maximum stiffness <em>K</em>₀, critical dislocation <em>δ</em>₀, and degradation rate <em>d'</em>. The proposed model effectively characterizes the sharp variations in shear forces acting on segments and joints, providing significant advantages for identifying vulnerable locations under extreme loads or joint performance degradation scenarios. The parametric study reveals that decreasing initial maximum shear stiffness <em>K</em>₀ increases tunnel settlement and joint dislocation while reducing segment bending moments and shear forces. For critical dislocation <em>δ</em>₀, lower values reduce the failure threshold, with significant joint failures corresponding to circumferential joint dislocations of approximately 3.8 mm occurring at 0.2×<em>δ</em>₀, particularly near surcharge boundaries at -15 m and 15 m. Variations in degradation rate <em>d'</em> show minimal impact because the joint dislocations remain within the high-stiffness range under the studied scenarios.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"168 ","pages":"Article 107138"},"PeriodicalIF":7.4,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261968","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}