Tunnelling and Underground Space Technology最新文献

{"title":"Analysis of nonlinear elastic spatiotemporal characteristics of the shallow subsurface","authors":"Qian Liu ,&nbsp;Xuan Feng ,&nbsp;Bingrui Chen ,&nbsp;Michael Fehler ,&nbsp;Enhedelihai Nilot","doi":"10.1016/j.tust.2024.106213","DOIUrl":"10.1016/j.tust.2024.106213","url":null,"abstract":"<div><div>During and after the destruction of underground structures, the elastic properties of subsurface rocks may undergo significant changes. Monitoring and detecting these subtle changes in elastic properties require techniques with high precision and high spatiotemporal resolution, which are challenging to achieve with conventional geophysical methods. Although nonlinear elastic characteristics have been used in seismic monitoring of faults and volcanoes, monitoring on fine spatiotemporal scales remains difficult. In this study, we developed a new technique to simultaneously monitor the nonlinear elastic properties of near-surface structures from both temporal and spatial perspectives by recording continuous seismic noise. We conducted a four-day continuous environmental noise monitoring campaign along a dense seismic array in Singapore. During the monitoring period, rock mass damage occurred along the measurement line. Using an approach analogous to “pump-probe” techniques, we analyzed the changes in nonlinear elastic properties during the local damage process at high spatiotemporal resolution. The results indicate that local damage can influence the nonlinear elastic behavior across the entire array. However, there are significant differences between the undamaged and damaged areas, as well as across different stages of damage. These observations and insights can provide timely warnings of minor changes in urban underground spaces, helping to prevent more significant damage and allowing for the implementation of effective, targeted measures. Moreover, this technique can accurately detect existing underground collapses and anomalous geological structures, which has important engineering implications for the detection of urban subsidence and the exploration of underground cavities in mining areas. It can play a crucial role in monitoring urban underground structural changes and providing early warnings of natural disasters areas.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106213"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637749","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":"Full-scale test study on the mechanical response of ultra-large section jacking prestressed concrete cylinder pipe (JPCCP) under axial jacking force","authors":"Hao Zhou ,&nbsp;Sheng Huang ,&nbsp;Baosong Ma ,&nbsp;Haifeng Zhang ,&nbsp;Xuhong Tan ,&nbsp;Yahong Zhao ,&nbsp;Peng Ma ,&nbsp;Xinhui Su ,&nbsp;Yingjie Wei","doi":"10.1016/j.tust.2024.106194","DOIUrl":"10.1016/j.tust.2024.106194","url":null,"abstract":"<div><div>Jacking prestressed concrete cylinder pipe (JPCCP) represents an innovative composite pipe technology well-suited for water supply and drainage projects. Currently, JPCCP designs frequently reference existing prestressed concrete cylinder pipe (PCCP) and pipe jacking standards, neglecting the impact of axial jacking force on the composite structure’s performance and the highly nonlinear issues encountered during the jacking process, such as concrete cracking, dislocation, and prestress loss. To thoroughly investigate the structural performance of JPCCP, this study, conducted in conjunction with the ultra-large-section JPCCP project in China, carried out axial loading tests both within the launching shaft and before entering the soil. The mechanical response of the concrete structure during the jacking process was investigated, culminating in the formulation of an axial strain calculation model for JPCCP. The results indicate that, owing to the combined effects of non-full-section eccentric compression and jacking force transmission, the axial deformation of the exterior-reinforced concrete was generally greater than that of the intermediate concrete, and the transfer of jacking force within the exterior-reinforced concrete was more pronounced. Additionally, the concrete deformation at the spigot end was marginally smaller than at the bell end, exhibiting more uniform deformation; however, abrupt changes in the cross-section at the spigot end can induce localized tensile stress areas. The discrepancies between theoretical calculations and actual test results remain within 10%, and the impact of prestress loss on different layers of concrete was inconsistent. This investigation into the structural performance and calculation model of ultra-large section JPCCP furnishes valuable insights for the design and construction of JPCCP.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106194"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637790","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":"3D deformation analysis in a metropolitan area during ongoing subway construction using time series InSAR","authors":"Ajay Saraswat ,&nbsp;Ya-Lun S. Tsai ,&nbsp;Fang-Chiung Chen ,&nbsp;Jen-Yu Han","doi":"10.1016/j.tust.2024.106190","DOIUrl":"10.1016/j.tust.2024.106190","url":null,"abstract":"<div><div>Unprecedented urban development poses significant subsidence challenges, primarily attributed to underground construction activities. Conventional approaches for monitoring these underground operations can be cumbersome. Therefore, time-series InSAR techniques emerges as a promising approach to quantify these deformations with high spatio-temporal details. However, distinguishing subsidence from city-scale deformation patterns often presents difficulties. Additionally, most previous studies concentrated on vertical deformation neglecting horizontal motions, thus hinder the comprehensive understanding of deformation dynamics. Lastly, the monitoring of deformations during ongoing subway construction has rarely been conducted. Therefore, this study employed PS-InSAR techniques to integrate Sentinel-1A ascending and descending datasets over the period from 2018 to 2023, with the aim of comprehensively extracting 3D deformation patterns, incorporating both vertical and horizontal components. Automatic methodologies were employed to distinguish the deformation caused by groundwater fluctuations and subway construction. The robustness of the results was statistically validated using geodetic leveling datasets. The results of the case study revealed vertical and horizontal deformations, with the vertical component being more prominent. Within the vertical deformation zones, localized horizontal deformations were evident due to their abrupt directional shift, albeit with a lesser magnitude. Persistent uplift was identified through East-North-Up (ENU)-derived vertical deformation at the rates of 8.04 and 6.85 mm/yr, respectively, in the test area. Long-term groundwater rebounds were observed, corresponding to a 1 mm uplift for every 1 m rise. The maximum cumulative subsidence recorded was 1 mm at the G07 MRT station, well within safe allowable limits. The findings are grounded in methodological advancements that hold the potential for comprehending deformation patterns on a global scale. Consequently, a much comprehensive and efficient monitoring of the ground deformation of a subway construction project can be achieved by employing the proposed approach.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106190"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637791","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":"Macro/meso-evolution of shear behavior of sand-steel interface in pipe jacking via digital image correlation (DIC) technology","authors":"Kaixin Liu ,&nbsp;Rudong Wu ,&nbsp;Baosong Ma ,&nbsp;Peng Zhang ,&nbsp;Cong Zeng","doi":"10.1016/j.tust.2024.106197","DOIUrl":"10.1016/j.tust.2024.106197","url":null,"abstract":"<div><div>The shear behavior of the pipe-soil interface determines the frictional resistance of pipe jacking. In the interfacial direct shear tests of well-graded dense sand against steel pipe under both unlubricated and lubricated scenarios, the shear stress initially exhibits hardening followed by softening. The shear band forms in the hardening stage, and significant morphology of the shear band varies in the softening stage. Eventually, the shear band exhibits a bell-shaped distribution in the pattern of horizontal displacement influenced by boundary conditions and fabric anisotropy. Coarse particles exhibit greater displacement and more intense softening due to larger initial void ratios and rotational radius, while specimens with more fine particles possess smaller maximum vertical displacement away from the interface and larger critical interface friction angle. Increased normal stress restricts particle displacement, resulting in larger shear displacement at peak state, more severe particle breakage, reduced shear band thickness, and increased peak interface friction angle. The shear stress reaches the critical stage earlier with bentonite slurry (<em>ω</em> = 6 %) due to reduced dilatancy and particle breakage. When the slurry concentration exceeds 14 %, overall sliding of particle displacement occurs instead of the layered distribution with increased vertical particle movement and noticeable stress softening. Continuous accumulation of irreversible dilation might induce forward movement of overlying soil. Moreover, excessive slurry concentration increases hardening and interfacial friction coefficient.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106197"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637603","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":"Integrated optimization of capacity allocation and timetable rescheduling for metro-based passenger and freight cotransportation","authors":"Zhen Di ,&nbsp;Jun Luo ,&nbsp;Jungang Shi ,&nbsp;Jianguo Qi ,&nbsp;Shenghu Zhang","doi":"10.1016/j.tust.2024.106186","DOIUrl":"10.1016/j.tust.2024.106186","url":null,"abstract":"<div><div>Multimodal integration can effectively address the challenges of sustainable urban freight, and utilizing a metro-based passenger and freight cotransportation system during off-peak hours represents a viable interim solution before establishing an underground logistics system. Given the constraints related to passenger carriage crowding, this study explores an integrated optimization problem that involves capacity allocation and timetable rescheduling for metro-based passenger and freight cotransportation lines under a train-shared mode. The final decision-making includes determining the size of the train fleet, the train timetable, the arrangement of carriages, and the assignment of freight flow. Since demand arrival rates are considered continuous functions over time, this integrated problem is formulated as a nonlinear mixed-integer model. To address the most complex aspects of the model, a gradient-based heuristic algorithm is proposed. Finally, numerical examples using real metro lines are provided to test the applicability and effectiveness of the proposed model and algorithm, and the impact of metro-based freight on passenger experience is also analyzed.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106186"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637793","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":"UPUCS: Spatial evaluation of user-perceived comfort in underground commercial space","authors":"Yangbin Zhang ,&nbsp;Zhiqiang Xie ,&nbsp;Xiaoqing Zhao ,&nbsp;Junwei Pu ,&nbsp;Yuenan Wang ,&nbsp;Bo Xiong","doi":"10.1016/j.tust.2024.106169","DOIUrl":"10.1016/j.tust.2024.106169","url":null,"abstract":"<div><div>With underground commercial space (UCS) increasingly becoming an essential area in the daily life of citizens, how to spatially quantify users’ comfort in underground commercial space and enhance the willingness of users to use underground facilities has become an urgent problem that needs to be solved. In order to improve the Perceptual impression of UCS and quantitatively assess users’ Perception level when they are in UCS from a spatial perspective, this paper constructs a User Perception of the Underground Commercial Space (UPUCS) framework. Taking the subway commercial space of Beiyun in Kunming, China, as an example, a questionnaire survey was conducted to understand users’ needs, and the perception of comfort of underground space was quantitatively evaluated from three dimensions: sensory, psychological, and device. The priority of indexes is defined by combining the analytic hierarchy process (AHP) and the importance-performance analysis (IPA). To put forward specific improvement suggestions for each index, 1 m × 1 m fine sensing grid unit was used for spatial analysis. The findings are as follows: (1) Device perception is the most concerned dimension of Beiyun users. (2) The average score of users’ satisfaction with the indexes in the research area (Performance) was 4.085, and the average index weight (Importance) was 0.083. Most indexes are below-average satisfaction and need to be improved. (3) The spatial analysis results show that 28 key low-performance areas in Beiyun affect users’ willingness to use UCS. (4) The analysis of the perception index combined with spatial quantification can help to put forward targeted suggestions for improvement. Based on the UPUCS spatial analysis results, this paper can provide specific suggestions for UCS improvement and help build the UCS desired by users.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106169"},"PeriodicalIF":6.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637794","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":"From pixel to infrastructure: Photogrammetry-based tunnel crack digitalization and documentation method using deep learning","authors":"Aohui Ouyang ,&nbsp;Vanessa Di Murro ,&nbsp;Mehdi Daakir ,&nbsp;John Andrew Osborne ,&nbsp;Zili Li","doi":"10.1016/j.tust.2024.106179","DOIUrl":"10.1016/j.tust.2024.106179","url":null,"abstract":"<div><div>Crack detection and documentation play a vital role in the asset management of large-scale tunnel complexes. This study proposes a computer vision-based tunnel crack data management method enabling 3D visualization, quantification, and documentation into structured data. The method reconstructs sparse point clouds with Structure from Motion (SfM) and cleans the irrelevant tunnel facilities with a two-stage filtering method. The denoised 3D point clouds are then fitted with customised meshes and textured into 3D reconstruction models. The flat scaled orthomosaic is generated by the cylindrical unrolling. Deep learning methods are employed for pixel-level crack detection in this high-resolution image for the extraction of crack location and quantification.</div><div>Applied to four tunnel sections of CERN, the European Organization for Nuclear Research, the method presents the spatial crack distributions and quantifies crack dimensions. In addition, the original unstructured tunnel image data of 1024 MB / meter is converted to structured tabular data of 0.3 MB / meter. The quantification result provides a crack statistical analysis tool, revealing that the crack length meets the log-normal distribution indicating the inherent fractural characteristic of tunnel linings.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106179"},"PeriodicalIF":6.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637883","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":"Mechanical behavior and damage evolution of tunnel lining structure under the impact of derailment of high-speed train","authors":"Yuqi Wang ,&nbsp;Xiaopei Cai ,&nbsp;Lei Zhao ,&nbsp;Tao Wang ,&nbsp;Yuan Xin ,&nbsp;Yi Liu","doi":"10.1016/j.tust.2024.106198","DOIUrl":"10.1016/j.tust.2024.106198","url":null,"abstract":"<div><div>In deep-buried long tunnels, train derailment accidents pose a serious threat to the stability of the tunnel lining structures and the safety of personnel along the line. To address the impact damage to the secondary lining caused by high-speed train derailments, a three-dimensional nonlinear dynamic analysis model of the Electric Multiple Unit (EMU) − lining − soil system was established. The advantages of this model include: it fully considers the complex streamlined design of the EMU front end, the nonlinearity of lining materials, and the M−C elastic structural model of the soil, allowing for accurate simulation of the contact and deformation between the EMU and the lining. The results indicate that the first 30 ms of the collision process are extremely intense, primarily involving the first three train vehicles. Among these, the head vehicle experiences the greatest reduction in kinetic energy and plastic dissipated energy, resulting in the most severe plastic deformation of the vehicle body. The impact load exhibits a distinct multi-peak characteristic, mainly composed of lateral impact force components. The area of displacement change in the lining expands continuously along the direction of the train, with peak displacements stabilizing after 30 ms. The lining primarily suffers from tensile failure, with multiple tensile cracks appearing in areas distant from the collision, while compressive damage is mainly concentrated at the point of direct impact. As the collision angle increases, the range of compressive damage along the longitudinal direction becomes narrower. The ratio of tensile damage area to compressive damage area is mainly influenced by the collision angle. In the design of tunnel structures for impact resistance, special attention should be paid to the lateral impact resistance and tensile failure capacity of the tunnel structure.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106198"},"PeriodicalIF":6.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637559","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 design system for Active-Passive combined support considering pre-tension force limited by geology in soft rock tunnels","authors":"Jinchao Liu ,&nbsp;Bo Wang ,&nbsp;Qiran Ning ,&nbsp;Dong Wang","doi":"10.1016/j.tust.2024.106201","DOIUrl":"10.1016/j.tust.2024.106201","url":null,"abstract":"<div><div>The design of active–passive support parameters traditionally relies on rock mass classification. However, the ultimate load of anchors in soft rock is significantly constrained by geological conditions and is not considered in rock mass classification methods. Consequently, the constant pre-tension force for the same rock mass classification poses a risk of anchor system tension failure. The paper introduces a dynamic design system for active–passive combined support to bridge this gap, considering the interplay between geological conditions and pre-tension force. The system established a predictive model for pre-tension force under geological conditions using on-site monitoring data and B-P neural networks. Considering the instantaneous loss during pre-tension force locking to determine effective pre-stress, it then utilized numerical simulation, on-site monitoring, and B-P neural networks to correlate pre-stress, geological conditions, passive support parameters, and rock deformation. Support parameters were subsequently adjusted based on predicted rock deformation in a predetermined optimization sequence. The system was taken to practical application in the Muzhailing Highway Tunnel. The results indicated that the predictive model for designed pre-tension force values achieved goodness of fit of 0.701 and mean absolute percentage error (MAPE) of 6.51%, guiding pre-tension force design. Additionally, a rock deformation prediction model, considering effective pre-stress and constructed using numerical simulation and field-measured data, attained an R-squared value of 0.947 and an MAPE of 2.76%. Practical application on three cross-sections demonstrated a high proportion of anchor holes reaching the designed pre-tension force (94%, 91%, and 97%, respectively), preventing anchoring system failure during tensioning. Predicted rock deformation values under designed support parameters closely match actual values, with percentage errors of 1.13%, 6.73%, and 2.15%, respectively. These outcomes contribute valuable insights to the design methodology of active–passive combined support in soft rock tunnels.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106201"},"PeriodicalIF":6.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656222","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":"Gas explosion overpressure loads in utility tunnels under different pipe support spacing","authors":"Lei Pang ,&nbsp;Wei Li ,&nbsp;Kai Yang","doi":"10.1016/j.tust.2024.106193","DOIUrl":"10.1016/j.tust.2024.106193","url":null,"abstract":"<div><div>To investigate the effects of pipe support system characteristics on gas explosion overpressure loads in utility tunnel gas compartments, a 200 m × 2 m × 3 m model of a typical Chinese utility tunnel was constructed using CFD dynamics. Analysis of spatial and temporal distributions of explosion overpressure load under different support spacings. The results indicated that a short support spacing (<em>L</em> = 5 m) contributes to a more uniform distribution of the gas cloud and enhanced the average flame propagation velocity, whereas a medium support spacing (<em>L</em> = 15 m, 25 m) significantly increased the peak overpressure and instantaneous flame velocity. The explosion overpressure curve showed a multipeak structure, with peak P1 caused by the precursor shock wave and peaks P2–P4 caused by the reflected wave. Within 70 m, the secondary reflected wave P3 dominated, and within 130–200 m, the first reflected wave, P2, played a major role. The peak overpressure loads at different support spacings decreased and subsequently increased along the length of the utility tunnel, and the maximum peak overpressure load was reached at the end. The peak overpressure in the same cross-section is unevenly distributed; the closer to the far-end wall, the more significant the difference, and the maximum overpressure usually appears near the top of the tunnel. According to the quantitative relationship between the peak explosion overpressure and support spacing, the optimised design of the pipe support spacing should not be less than 25 m.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"155 ","pages":"Article 106193"},"PeriodicalIF":6.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656221","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}