Underground Space最新文献

{"title":"Land-sea integrated suitability evaluation of underground space based on Pythagorean fuzzy Bayesian network","authors":"Xinyu Liu ,&nbsp;Hongjun Liu ,&nbsp;Jie Dong ,&nbsp;Peng Yu ,&nbsp;Honghua Liu ,&nbsp;Guanghua Cheng","doi":"10.1016/j.undsp.2025.04.004","DOIUrl":"10.1016/j.undsp.2025.04.004","url":null,"abstract":"<div><div>Scientific development and utilization of urban underground space is an inevitable choice for sustainable urban development. However, in the previous suitability evaluation of underground space in coastal cities, the development potential of underground space in the sea area is not considered. Therefore, this study takes the coastal zone of Jiaozhou bay as the study area, establishes evaluation index systems for land and sea areas separately, and explores a new model for evaluating the suitability of underground space in coastal cities by integrating land and sea. In addition, an underground space suitability evaluation model based on the integration of Pythagorean fuzzy sets and Bayesian network is proposed. Firstly, the Pythagorean triangular fuzzy numbers are used to expand the fuzzy range of expert opinions. Then the Pythagorean triangular fuzzy hybrid geometric operator is used to realize the aggregation of expert opinions to solve the difficulty of obtaining the node conditional probability table by the traditional Bayesian network model of underground space suitability evaluation. Finally, the Pythagorean fuzzy Bayesian network is used as an evaluation tool to carry out the underground space suitability evaluation. Based on the evaluation result and urban planning, the overall planning and functional zoning guidelines for underground space development in the study area are given and the suitability and engineering construction difficulty analysis on the second subsea tunnel of Jiaozhou bay is conducted. The research results can provide a valuable reference for the coastal city planning department to develop and utilize underground space.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 197-215"},"PeriodicalIF":8.3,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771150","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 the Optuna-NGBoost-SHAP model for estimating ground settlement during tunnel excavation","authors":"Yuxin Chen ,&nbsp;Mohammad Hossein Kadkhodaei ,&nbsp;Jian Zhou","doi":"10.1016/j.undsp.2025.03.006","DOIUrl":"10.1016/j.undsp.2025.03.006","url":null,"abstract":"<div><div>This study aims to develop and evaluate a natural gradient boosting (NGBoost) model optimized with Optuna for estimating ground settlement during tunnel excavation, incorporating Shapley additive explanations (SHAP) to perform interpretability analysis on the model’s estimation results. The model’s predictive performance was comprehensively assessed using datasets from two earth pressure balance shield tunneling projects in Changsha and Zhengzhou, China. Comparative analyses demonstrated the superior accuracy and generalization capability of the Optuna-NGBoost-SHAP model (training set: <em>R</em>² = 0.9984, MAE = 0.1004, RMSE = 0.4193, MedAE = 0.0122; validation set: <em>R</em>² = 0.9001, MAE = 1.3363, RMSE = 3.2992, MedAE = 0.3042; test set: <em>R</em>² = 0.9361, MAE = 0.9961, RMSE = 2.5388, MedAE = 0.2147). SHAP value analysis quantitatively evaluated the contributions of input features to the model’s estimations, identifying geometric factors (distance from the shield machine to the monitoring section and cover depth) as the most important features. The findings provide robust decision support for safety management during tunnel construction and demonstrate the reliability and efficiency of the Optuna-NGBoost-SHAP framework in estimating complex ground settlement scenarios.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 60-78"},"PeriodicalIF":8.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704189","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":"Data-driven modeling for evaluating deformation of a deep excavation near existing tunnels","authors":"Fengwen Lai ,&nbsp;Songyu Liu ,&nbsp;Jim Shiau ,&nbsp;Mingpeng Liu ,&nbsp;Guojun Cai ,&nbsp;Ming Huang","doi":"10.1016/j.undsp.2025.04.003","DOIUrl":"10.1016/j.undsp.2025.04.003","url":null,"abstract":"<div><div>This study explores an integrated framework combining in-situ test-based numerical and data-driven modeling to assess the performance of a deep excavation-tunnel system. To achieve the goal, a case history of deep excavations adjacent to existing tunnels in silt/sand-dominated sediments is introduced to establish a base three-dimensional finite element (3D-FE) model. In-situ tests such as cone penetration test (CPT/CPTU) and seismic dilatometer test (DMT/SDMT), as an alternative to laboratory testing, are used to determine a set of advanced constitutive model parameters. The established excavation-tunnel numerical model is then validated against filed monitoring data. A dataset from numerical simulation is created for training and testing four machine learning models (i.e., artificial neural network (ANN), support vector machines (SVM), random forest (RF), and light gradient boosting machine (LightGBM)), which predict the maximum wall deflection, ground surface settlement, horizontal and vertical displacements of the tunnel. Results show that the ANN model outperforms other models in prediction capacity. Its generalization ability in practice is further enhanced by comparing field measurement data and empirical equations. The findings suggest that, with the integrated in-situ tests, FE and ANN modeling could be used to predict deformation responses of deep excavations close to existing tunnels in soft soil. The present study is useful and valuable for practical risk assessment and mitigation decisions.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 162-179"},"PeriodicalIF":8.3,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739581","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":"Impact of ground motion characteristics on the seismic fragility of circular tunnels","authors":"Zhong-Kai Huang ,&nbsp;Dong-Mei Zhang ,&nbsp;Wu-Yu Zhang ,&nbsp;Yong-Bo Li","doi":"10.1016/j.undsp.2024.09.008","DOIUrl":"10.1016/j.undsp.2024.09.008","url":null,"abstract":"<div><div>The seismic performance of tunnel structure can be examined by fragility analysis, which determines the probability that demand will exceed capacity for a given hazard intensity. Although it is commonly understood that earthquake uncertainties dominate fragility features, the implication of ground motion characteristics on the shield tunnel fragility analysis has not been comprehensively explored. Thus, this study aims to compare the effects of various earthquake characteristics on the fragility of the investigated shield tunnels. To this end, a typical shield tunnel was chosen and modelled using the finite element software. In addition, to account for typical ground motion characteristics, various ground motion sets, including near-field no plus motions (NFNP), near-field motions with a pulse (NFP), and far-field motions (FF), are selected, and a fragility analysis was assessed for every set of ground motion. The fragility curves were generated employing peak ground acceleration (PGA) as the intensity measure (IM) and tunnel drift as the damage measure (DM). The findings indicate that shield tunnels subjected to NFP may be more vulnerable compared to those subjected to NFNP and FF ground motions. This study’s findings highlight the vital role of ground motion characteristics in evaluating the fragility of shield tunnels. Moreover, the results may inform future seismic risk and resiliency evaluations regarding the importance of considering or disregarding the impacts of ground motion characteristics on tunnel vulnerability.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 180-196"},"PeriodicalIF":8.3,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757373","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 study on the soil arching effect caused by deep-buried shield tunneling","authors":"Xu Song ,&nbsp;Chang-Wei Miao ,&nbsp;Ren-Peng Chen ,&nbsp;Xiao-Ning Deng ,&nbsp;Yu Zhang ,&nbsp;Jun-Qing Wang ,&nbsp;Xiao-Fei Chen","doi":"10.1016/j.undsp.2025.04.002","DOIUrl":"10.1016/j.undsp.2025.04.002","url":null,"abstract":"<div><div>The soil arching effect induced by deep-buried shield tunneling strongly influenced the ground stress and displacement. Therefore, revealing the evolution mechanism of the soil arching effect is a prerequisite for accurately predicting the tunnel load, which has not been understood in deep-buried conditions. Three model tests and eight numerical simulations were carried out to enhance the understanding of the soil arching evolution, in which the stress field, displacement field, and strain field were analysed. The experimental and numerical results indicated that the ground reaction curve presented a two-stage development process of an initially linear decrease followed by a gradual decrease. Compared with the theoretical tunnel loads, the measured and numerical values are relatively larger due to the loosening earth pressure theory ignoring the evolution process of the soil arching effect. The soil arching height decreases with the increase in stress level, measuring 1.75<em>D</em> (the initial diameter of the model tunnel), 1.65<em>D</em>, and 1.61<em>D</em>, respectively, which results from the lagging evolution of the soil arching effect under high-stress conditions. The formation of the shear band was affected by the stress-dependent dilatancy of the soil. At low stress levels, the shear band develops vertically upward. In contrast, at higher stress levels, the shear bands tilt towards the lateral side.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 129-141"},"PeriodicalIF":8.2,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713827","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":"Continuum-discrete coupling model for mechanical response analysis of tunnels subjected to non-uniform reverse faulting","authors":"Zhenning Ba ,&nbsp;Yao Wang ,&nbsp;Zhiwei Fang ,&nbsp;Dongqiao Li","doi":"10.1016/j.undsp.2025.03.005","DOIUrl":"10.1016/j.undsp.2025.03.005","url":null,"abstract":"<div><div>In recent decades, there have been numerous reports of damage cases involving tunnels crossing active faults. The mechanical response and failure mechanisms of cross-fault tunnels have become a key issue in the field of tunnel engineering. This study established a continuum-discrete coupling model comprising intact rock mass, fault zones, and tunnel. In this model, the tunnel and intact rock are modeled as continuous media, while the fault zone is modeled as a discrete medium. The non-uniform fault displacement is adopted to simulate the mechanical response and damage patterns of tunnels crossing active faults under reverse faulting. The simulation results are validated by comparison with the damage of Longchi tunnel observed from 2008 Wenchuan earthquake in China, as well as the experimental phenomenon from the model test. The results demonstrate that the proposed coupling model effectively reproduces the tunnel failure modes caused by reverse faulting. In addition, the high consistency between the simulation results and experimental data further confirms computational accuracy and reliability of the coupling model. A parametric analysis based on the Xianglushan tunnel in China is carried out to investigate the effects of fault displacements, fault widths, dip angles and fault zone rock mass qualities on damage patterns of crossing-fault tunnels. This study provides a valuable reference for seismic fortification of the tunnel crossing reverse faults.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 44-59"},"PeriodicalIF":8.2,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696420","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":"Rockburst proneness index of surrounding rock considering rock mass quality and excavation disturbance factor","authors":"Fengqiang Gong ,&nbsp;Lei Xu ,&nbsp;Shuren Wang ,&nbsp;Qinghe Zhang ,&nbsp;Yong Huang","doi":"10.1016/j.undsp.2025.03.004","DOIUrl":"10.1016/j.undsp.2025.03.004","url":null,"abstract":"<div><div>Rockburst is an engineering phenomenon characterized by the release of elastic strain energy due to the dynamic failure of deep surrounding rock. The existing rockburst proneness indexes primarily focus on rock materials, failing to encompass rock mass quality and engineering excavation disturbance. On the basis of the potential elastic strain energy released by rock failure, five kinds of rockburst proneness indexes of surrounding rock are established considering the rock mass quality and excavation disturbance factor. Firstly, the linear relationship between elastic modulus and residual elastic energy of rock materials (<em>A</em>_EF), the relationships between elastic and deformation moduli, as well as the link with rock mass quality evaluation indexes (i.e., rock mass rating (RMR), basic quality index of rock mass (BQ), and geological strength index (GSI)) and deformation modulus, were used to derive five assessment model of rockburst proneness for surrounding rock. Secondly, the rockburst proneness degree for three grades of surrounding rock (I: excellent rock, II: good rock, and III: fair rock) was assessed utilizing the RMR₈₉, BQ, and GSI indices, and the influence of excavation disturbances on the residual elastic energy of surrounding rock (<span><math><mrow><msubsup><mi>A</mi><mrow><mi>EF</mi></mrow><mi>SR</mi></msubsup></mrow></math></span>) was analysed. In general, the higher the quality of rock mass and the lesser the disturbance factor, the greater the rockburst proneness degree of surrounding rock. The accuracy of proposed rockburst proneness indexes was validated by using the field data from 27 rockburst cases. The results demonstrate that the discriminant grade of rockburst index based on GSI is basically consistent with the actual occurrence grade of rockburst cases, with an accuracy of 93%, which can be used as a recommended method for evaluating the rockburst proneness degree of surrounding rock. Finally, the shortcomings of rockburst proneness assessment model are discussed, and the improvement direction is elucidated.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 1-21"},"PeriodicalIF":8.2,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653197","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-parametric probabilistic seismic capacity model for the stochastic interaction system of soil-subway station structures","authors":"Minze Xu ,&nbsp;Chunyi Cui ,&nbsp;Hailong Liu ,&nbsp;Jingbo Li ,&nbsp;Jingtong Zhao ,&nbsp;Chengshun Xu","doi":"10.1016/j.undsp.2025.03.003","DOIUrl":"10.1016/j.undsp.2025.03.003","url":null,"abstract":"<div><div>A reasonable seismic capacity model is crucial for establishing the seismic performance level system and evaluating the seismic reliability of subway station structures. However, the deterministic structural and geotechnical mechanical parameters are usually applied to calibrate the seismic performance levels of subway station structures in the traditional seismic capacity analysis, which ignores the stochasticity of the soil-subway station interaction system. To overcome the challenge caused by the stochastic interaction system, the probability space partition method and stochastic pushover analysis method are combined to develop a calibration strategy of seismic performance levels considering the complete probabilistic information of the stochastic interaction system, and the non-parametric probabilistic seismic capacity models of the subway station structure are further established based on the principle of probability conservation in this paper. A subway station is also taken as the prototype to investigate the applicability of the proposed strategy and the influence of system randomness on the seismic capacity of the subway station structure. The results demonstrate that the seismic performance levels calibrated according to the proposed strategy can effectively consider the complete probabilistic information of the interaction system, which are more rigorous than the existing performance levels. Meanwhile, the probability density evolution of the bearing capacity of the subway station structure is essentially a non-stationary stochastic process, and the non-parametric probability density curves of seismic capacity display noticeable multi-peak characteristic. Moreover, the seismic capacity for <em>L</em>_P1 and <em>L</em>_P2 levels is more sensitive to the variability of geotechnical parameters above and below the structure, while the former for <em>L</em>_P3 and <em>L</em>_P4 levels is more sensitive to that on both sides of the structure. The relevant conclusions can provide some guidance for seismic design and improvement of the performance limits of underground structures in the related codes.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 79-103"},"PeriodicalIF":8.2,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704191","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 foundation pit uplift mechanism and tunnel response induced by deep excavation under complex support system: A case study","authors":"Zhiguo Zhang ,&nbsp;Jian Wei ,&nbsp;Junjie Li ,&nbsp;Linlong Mu ,&nbsp;Wei Wo ,&nbsp;Yin Ni","doi":"10.1016/j.undsp.2025.03.002","DOIUrl":"10.1016/j.undsp.2025.03.002","url":null,"abstract":"<div><div>Pit excavation work often occurs directly above metro tunnels, causing adverse effects on the underlying existing operational shield tunnel. Current simplified solutions mainly adopt stress release method to reflect excavation of foundation pit, which is inappropriate for large soil uplift. A two-stage analysis based on modified Sagaseta solution with displacement-controlled boundary condition and tunnel-soil coordinated constrain is promoted for estimating the mechanical behavior of tunnel with joints. Specifically, the modified Sagaseta solution including gravity effects is firstly used to obtain the soil greenfield displacement caused by foundation pit excavation. Secondly, the Pasternak foundation model, incorporating tunnel-soil ellipse-shaped deformation, combines a variable stiffness Timoshenko beam at tunnel joints and ultimately obtains the tunnel displacement curve. Furthermore, a three-dimensional numerical simulation is also conducted for Jinqiao metro superstructure excavation project that involves a foundation pit situated directly above an existing metro tunnel. The feasibility of simplified solutions is verified with numerical simulation solutions and an engineering case. For investigating the key parameters, the parametric analyses are conducted, indicating that the greenfield displacement is highly related to modified uneven convergence Sagaseta solution. The ignoration of excavation width will overestimate the tunnel displacement as plane strain condition. Both equivalent bending and shear stiffness can only influence corresponding bending and shear tunnel deformation.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"24 ","pages":"Pages 104-128"},"PeriodicalIF":8.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713824","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":"Intelligent optimization of TBM cutter spacing and FDEM-based investigation of rock breakage considering brittleness","authors":"Youlin Qin ,&nbsp;Li Yu ,&nbsp;Mingnian Wang ,&nbsp;Zhaohui Chen ,&nbsp;Hong Jin ,&nbsp;Mingyang Yu ,&nbsp;Songshen Wang","doi":"10.1016/j.undsp.2025.02.011","DOIUrl":"10.1016/j.undsp.2025.02.011","url":null,"abstract":"<div><div>Cutter spacing is a key factor influencing the efficiency of TBM operations. Meanwhile, rock brittleness, as a critical indicator of rock fracture, significantly influences fragmentation behavior and rock-breaking efficiency. This study investigates the influence of rock brittleness on rock-breaking through numerical penetration experiments based on the hybrid finite-discrete element method (FDEM) and proposes four intelligent hybrid models to optimize cutter spacing. The results show that as the rock brittleness index (BI) increases from 4.731 to 32.588, the count, depth, width, and proportion of tensile cracks increase, and crack propagation shifts from horizontal to oblique orientations. Moderate cutter spacing (90–110 mm) is optimal for generating tensile cracks. The rock-breaking force increases significantly with higher BI; for instance, at 80 mm spacing, the maximum force for rock with a BI of 13.134 is 5.51 times that for rock with a BI of 4.731. The influence of BI on cutter work and specific energy (SE) is more substantial than the effect of cutter spacing. As BI increases, both cutter work and SE rise considerably. Among the proposed models, the particle swarm optimization and extreme gradient boosting (PSO-XGBoost) model demonstrates the highest performance, achieving an <em>R</em>² of 0.994, VAF of 99.418%, RMSE of 0.987, and MAPE of 5.217% on the test datasets. An optimization method for cutter spacing is proposed based on this model.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"23 ","pages":"Pages 379-402"},"PeriodicalIF":8.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604426","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}