Tunnelling and Underground Space Technology最新文献

{"title":"Regulating multi-directional passenger flow: Impact of obstacle position and flow level on pedestrian merging process","authors":"Hanchen Yu, Nan Jiang, Maoyu Li, Xinmiao Jia, Jixin Shi, Eric Wai Ming Lee, Lizhong Yang","doi":"10.1016/j.tust.2024.106336","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106336","url":null,"abstract":"Mass passenger flow and crowd gathering in subway stations raise the potential of crowd accidents. To improve the safety level in subway stations, it is crucial to investigate the crowd movement characteristics within specific structures with higher risk levels and regulate the passenger flow. The merging structure is common in subway stations with a larger scale of complex multi-directional movements and always be considered a potential bottleneck. It has been proven that specific geometric constraints in merging structures can significantly reduce traffic efficiency and expedite the formation of congestion by aggravating the conflicts among the crowds. However, there is still a lack of research on measures to improve the performance of existing merging structures. Previous findings show that properly set obstacles may increase the performance of bottleneck regions, which provides an opportunity to consider whether the obstacle effect can also be observed during the merging process. From this perspective, we carried out 39 groups of controlled experiments to investigate the impact of obstacle positions on the merging process under three different flow levels. A real human was used as the obstacle, and the distribution of different obstacle positions was divided into three regions. Our results demonstrate that setting the obstacle in certain regions will increase the performance of merging structures in terms of average outflow, velocity, and local density. The average velocity and outflow are increased by up to 6.82 % and 11.26 %, while the local density within the merging area is kept below 3.5 m<ce:sup loc=\"post\">−2</ce:sup>. In contrast, some other regions will generate less efficient outcomes and cause a higher probability of jamming on the merging process. The maximum reduction of average velocity and outflow is 30.99 % and 19.45 %, and the local density can exceed 5 m<ce:sup loc=\"post\">−2</ce:sup>. The performance of different obstacle positions is also affected by the flow level, and controlling the flow at a lower level is more beneficial for the merging process. Other microscopic parameters, such as channel utilization, detour degree, and personal distance, are also introduced to compare the impact of obstacle setups on pedestrian behaviors. The results provide a feasible way to improve the efficiency and safety level of merging structures in subway stations.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"5 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867663","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":"Monitoring the circumferential cracking of inner concrete core in prestressed concrete cylinder pipe during wire-wrapping using distributed optical fiber sensors","authors":"Shuai Liu, Yanlong Li, Ye Zhang, Minghui Ma, Wen Qiu, Lei She, Heng Zhou, Kangping Li, Kaiyu Sun","doi":"10.1016/j.tust.2024.106330","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106330","url":null,"abstract":"In the manufacturing process of prestressed concrete cylinder pipe (PCCP), circumferential cracks often manifest in the inner concrete core. It poses a potential risk of pipe failure in engineering applications. This paper introduces the utilization of distributed optical fiber sensors for monitoring the circumferential cracking in the inner concrete core in PCCP. A test specimen, featuring a double-layer wrapping structure with an inner diameter of 3.40 m and a length of 5.00 m, was monitored during the wire-wrapping and lifting processes. The results reveal that the circumferential crack is positioned 0.20 m away from the top of the spigot after the second wire-wrapping. This location corresponds to the welding point of the spigot steel ring and the steel plate, situated within the tensile stress zone induced by the wire-wrapped zone. The primary cause for the cracking is stress concentration resulting from the abrupt profile change at the joint of the spigot steel ring and the steel plate. Notably, the lifting process exerts a negligible influence on circumferential cracking. The strains of the steel cylinder and concrete before and after the wire-wrapping process consistently exhibit elastic behavior.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"13 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867666","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":"Evaluation of rheology and washout resistance of cement-based grouts in water-rich strata","authors":"Xiaoming Liang, Kun Feng, Chenlin Wang, Zhenyu Hu, Chuan He","doi":"10.1016/j.tust.2024.106334","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106334","url":null,"abstract":"The grout in water-rich strata is at risk of being washed away. To investigate its retention capacity during the washout process, rheological parameters characterizing the mechanical properties of the grout were tested. Additionally, a comparative analysis was conducted on the prediction accuracy of different rheological models for cement-based grouts, and a recommended prediction model for the rheological parameters was provided. By combining a CFD numerical model, the process of grout being washed out in the stratum was analyzed. The study results indicate that the Bingham model is the most suitable for regression analysis of rheological parameters in cement-based grouts. In the static washout process, reducing Water/Binder and Binder/Sand while increasing Bentonite/Water improves the resistance of grout to washout, with Cement/Fly Ash having a relatively smaller impact. During dynamic washout, Binder/Sand either above or below 0.65 result in higher grout washout resistance. Additionally, grouting increases grout volume in the stratum, with the retention rate being minimally influenced by grouting pressure. The static washout effect showed an excellent correlation with plastic viscosity, while the dynamic washout effect was more significantly related to yield stress. When shear stress exceeds 3.5 and plastic viscosity exceeds 0.6, the influence of rheological parameters on grouting effectiveness and retention capacity becomes negligible. Considering the grouting process, retention rate and diffusion capacity, three reference ratios were proposed for different application needs.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"31 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867665","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":"Permanent tunnel support with reinforced shotcrete arches and forepoling in over-consolidated till and weathered rock. A case study based on the construction of the Bergås tunnel, Norway","authors":"Jorge Terron-Almenara, Karl Gunnar Holter, Pål Drevland Jakobsen, Bent Aagaard, Alf Kristian Lund","doi":"10.1016/j.tust.2024.106256","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106256","url":null,"abstract":"Ground support in tunnels excavated through weak ground conditions in Norway has normally consisted of reinforced shotcrete methods. However, in cases where exceptionally poor ground or soil tunnel conditions were expected, final support consisted of cast-in-place solutions designed in advance. Although reinforced shotcrete methods have proved satisfactory for a wide range of weak ground conditions, the adequacy of such support method solely to act as the final, permanent support and fully substitute cast concrete liner in soil tunnels has not been realized until the recent construction of the Bergås highway tunnel in northern Norway. In this tunnel, an unexpected portion of 70 linear m of the tunnel consisted of sedimentary deposits of glacial origin (tills) and a weathered, soil-like rock mass. In the present study, the ground behavior and the performance of reinforced shotcrete arches as permanent, final support in this soil portion are investigated. The findings suggest that the compact and over-consolidated tills pose favorable excavation conditions as evidenced by the monitored ground stability under full face excavation passes, and the low support loading during the advance through the soil zone. As such, a pragmatic design considering a permanent functional and stable ground support made of reinforced arches in the soil section was possible from the combination of the elements of the Scandinavian hard rock tunnelling with the principles of weak ground engineering, and pre-stabilization methods with grouted forepoling. The permanent tunnel support finally consisted of ribs of reinforced shotcrete (RRS), fiber reinforced shotcrete (FRS) and fully grouted steel rebar rock bolts, which substituted the pre-determined cast concrete lining that is traditionally used in soft tunnelling conditions. The approach is therefore innovative as it considers a cost-effective alternative with significantly lower concrete consumption, on the basis of a shotcrete-based support solution designed from a combination of elaborated design work, monitoring, ground characterization, and advanced numerical analyses.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"26 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867667","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":"Estimation of settlement-induced damage in masonry buildings from displacement measurements","authors":"Yiyan Liu, Harvey Burd, Derya Burcu Gulen, Korhan Deniz Dalgic, Ben Gilson, Alper Ilki, Sinan Acikgoz","doi":"10.1016/j.tust.2024.106314","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106314","url":null,"abstract":"In current engineering practice, building damage due to nearby ground excavation activities is typically quantified by processing displacement measurements. Building displacements at discrete points are used to determine deflection measures (such as angular distortion) which are then employed to estimate building strains using elastic beam models; damage is subsequently categorised according to the limiting tensile strain criteria. The reliability of this procedure relies on the extent to which the equivalent beam models employed in the analysis provide a realistic representation of the building behaviour. However, few published investigations are available on this issue. The current paper provides an appraisal of displacement-based building damage estimation techniques by employing digital image correlation displacement data collected from a recent experimental campaign on the settlement response of three half-scale masonry buildings. The results demonstrate that the treatment of buildings with equivalent beam models does not capture building deformation kinematics, potentially leading to inaccurate estimations of damage severity and location. An alternative strain interpretation procedure, inspired by an equivalent frame idealisation of a building façade with openings, is proposed. This procedure, which uses a limited number of displacement measurements, offers a robust interpretation of strains. Its effectiveness in estimating damage is assessed through experimental data. It is demonstrated that the current limiting tensile strain criteria need to be modified to provide a reliable estimation of crack widths when using the equivalent frame idealisation.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"39 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867669","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 study on the effect of different sealing ratios on the behavior of continuous spill fires in sloped tunnels","authors":"Weibing Jiao, Changkun Chen, Wuhao Du, Zida Lin, Yipeng Bao, Shishan Liu","doi":"10.1016/j.tust.2024.106288","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106288","url":null,"abstract":"Several spill fire experiments were carried out in a reduced-scale sealed tunnel, considering different discharge rates, sealing ratios, and initial sealing time. The burning characteristics of tunnel spill fires were analyzed. The results show that in the scenario of continuous fuel leakage, tunnel spill fires will eventually fall into three different burning behaviors as the sealing ratio increases: quasi-steady combustion, unsteady combustion diffusion, and self-extinction. The fundamental reason that the sealing ratio influences the burning characteristics of tunnel spill fires is that it alters the ventilation factor at the tunnel opening, thereby affecting the maximum burning rate of the liquid fuel. This leads to variations in the relative magnitudes of the discharge rate and evaporation rate, resulting in different diffusion regimes of the tunnel spill fire. Moreover, when the tunnel exits are sealed at the quasi-steady combustion stage, the three regimes of tunnel spill fires observed are similar to those observed when the exits are sealed at the initial moment. The transition mechanisms of various diffusion regimes were analyzed, and a correlation model between the critical sealing ratio and the discharge rate was established. Additionally, the temperature distribution law of the smoke below the tunnel ceiling under various sealing ratios was studied. The maximum smoke temperature rise exhibits two distinct regions of variation as the sealing ratio increases. When the sealing ratio is small, the maximum smoke temperature rise remains relatively steady with the increase of the sealing ratio. However, as the sealing ratio increases, the tunnel spill fire transitions to the ventilation-controlled, resulting in a reduced burning rate and a rapid decrease in the maximum smoke temperature. Empirical models characterizing the maximum temperature rise were developed for different sealing situations. This study could provide an essential reference for conducting emergency rescue operations during tunnel spill fires.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"24 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867671","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":"Tunnel lining defects identification using TPE-CatBoost algorithm with GPR data: A model test study","authors":"Kang Li, Xiongyao Xie, Junli Zhai, Biao Zhou, Changfu Huang, Cheng Wang","doi":"10.1016/j.tust.2024.106275","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106275","url":null,"abstract":"The quality of tunnel lining is critical for both construction integrity and safety. Ground Penetrating Radar is widely employed for tunnel lining inspections, but manual analysis is time-consuming and inefficient. This paper presents TPE-CatBoost, a machine learning method designed to identify typical defects in tunnel linings using GPR data. The CatBoost algorithm is used to classify defects, while the Tree-structured Parzen Estimator is employed to optimize hyperparameters. A full-scale model test with actual engineering materials was conducted, resulting in a dataset of 249,500 GPR A-scans, effectively addressing the challenge of limited data sources with known defect information. The SMOTE algorithm was utilized to mitigate the issue of imbalanced samples within the dataset. A novel feature extraction method, incorporating GPR waveform statistics and parameters, was developed and proved effective in defect identification. TPE-CatBoost achieved an accuracy of 0.92 in just 125 s, surpassing the performance of Naive Bayes, Support Vector Machines, Random Forest, and XGBoost. The method was successfully applied in the Shanggang Tunnel using an intelligent detection vehicle, significantly enhancing GPR efficiency. The results were validated against traditional data processing methods.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"42 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867670","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 structural performance of segmental linings of shield tunnels under loading–unloading-reloading condition","authors":"Dong-Lin Feng, Huai-Na Wu, Fan-Yan Meng, Si-Qi Yang, Ren-Peng Chen","doi":"10.1016/j.tust.2024.106331","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106331","url":null,"abstract":"The shield tunnel structure built in urban area may suffer from complex disturbance caused by adjacent construction, which leads to loading–unloading-reloading on the tunnel structure, causing accumulation of structural deformation and diseases. In this paper, an elaborate FEM numerical model of segmental linings was established for studying the structural performance of the linings under a loading–unloading-reloading condition which is simulating the complex urban disturbance. The results show that three different deformation modes (Full recovery, Partial recovery and Deformation growth combined with elastic recovery) for the segmental linings can be observed in the unloading process with different historic peak value of the load. A deformation growth phenomenon occurs at the beginning of unloading process in the combined recovery mode and the deformation increment is mainly derived from the change in geometric contact state of joint section. The increase of the load value in loading stage results in the enhancement of nonlinear characteristics and the deterioration of ultimate capacity for the longitudinal joints which directly weaken the deformation recoverability and ultimate capacity of the segmental linings. When the vertical deformation is greater than 50 mm, the deformation recovery rate <ce:italic>α</ce:italic><ce:inf loc=\"post\">re</ce:inf> declines to 0 % and the deformation decrease in elastic recovery stage is covered by the increase in deformation growth stage during unloading process. An index named deformation residual energy <ce:italic>E</ce:italic><ce:inf loc=\"post\">res</ce:inf> was proposed to evaluate the structural safety of the segmental ring. Its decrease can quantitatively reflect the accumulation of unrecoverable deformation and material damage caused by the disturbance conditions.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"117 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867675","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 role of wall slip and temperature in shield tail seal performance: A novel modeling approach","authors":"Dalong Jin, Yi Yang, Dajun Yuan, Xinggao Li, Jian Chen, Yangyang Gan, Shuai Zheng","doi":"10.1016/j.tust.2024.106333","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106333","url":null,"abstract":"The increasing number of tunnel construction projects utilizing shield machines has led to frequent occurrences of tail seal failure. Current models for predicting shield tail sealing performance often neglect crucial factors such as wall slip and temperature-dependent grease properties, leading to inaccurate predictions and suboptimal designs. This study presents a novel computational model that incorporates both wall slip and temperature effects to accurately predict the performance of seals. The model utilizes a finite element method approach with a non-Newtonian fluid model to capture the complex rheological behavior of the sealing material. The simulation results reveal that neglecting wall slip can lead to an underestimation of grease leakage amount and the water pressure resistance of the tail seal system, highlighting the critical importance of incorporating this effect in seal design. When the wall slip effect is considered, the breaking water pressure of the tail seal brush is 0.45 MPa, while the breaking water pressure is only 0.34 MPa when the wall is considered to be non-slip. Furthermore, it was demonstrated that temperature variations significantly influence the pressure distribution within the seal. When the temperature is 10 °C, the breakdown water pressure is 0.88 MPa, while when the temperature rises to 60 °C, the breakdown water pressure is only 0.07 MPa. This study provides a significant advancement in seal design by offering a more accurate and comprehensive model that incorporates both wall slip and temperature-dependent material properties. The model can facilitate the design of more reliable and efficient shield tail sealing systems.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"22 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867677","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":"Underground space in dry sand and effect of dredging on diaphragm wall using helical anchors − A model study","authors":"Ragini Vishwakarma, Satyendra Mittal, Vishwas A. Sawant","doi":"10.1016/j.tust.2024.106326","DOIUrl":"https://doi.org/10.1016/j.tust.2024.106326","url":null,"abstract":"Deep excavation has become inevitable for creating underground spaces due to the restricted space in urban areas. The diaphragm wall is an effective solution for restricting the lateral movement of soil and providing a sequence of stable excavation. The anchors in the backfill hold the diaphragm wall at its position and restrict its lateral movement and subsidence during excavation as well as serviceable time. The present research work has developed a scaled-down diaphragm wall with helical anchors based on past case histories of the deep excavations. Parameters such as offset distances (distance of the loading from the edge of the wall), anchor inclinations, and anchor lengths are varied. The footing offsets <ce:italic>x/H</ce:italic> = 0.1, 0.2, 0.3, and 0.4 (<ce:italic>x/H</ce:italic> is the ratio of horizontal distance between the edge of footing and wall to the height of the wall), anchor inclinations from 5° to 20° (with horizontal) and anchor lengths of 0.6<ce:italic>H</ce:italic> and 0.9<ce:italic>H</ce:italic> have been tried in model tests. Comparative analyses of anchored diaphragm wall versus unanchored diaphragm wall have been made based on the responses imparted by anchors. Thereby, an optimized design of anchors has been developed. It was observed that increasing the anchor inclination up to 15° relative to the horizontal reduced the pressure on the wall, lateral displacement, and subsidence near the wall. However, inclinations beyond 15° reduced the stability of the diaphragm wall. Additionally, the unanchored diaphragm wall experienced higher pressure than the anchored wall. The excavation depth was less when the offset distance of loading was closer to the wall due to excessive lateral pressure. The pressure on the anchored wall was reduced by 37 % when the offset distance increased from 0.1<ce:italic>H</ce:italic> to 0.4<ce:italic>H</ce:italic>. An increase in the length of the anchor from 0.6<ce:italic>H</ce:italic> to 0.9<ce:italic>H</ce:italic> caused a reduction in pressure on the wall by 31 %. The model tests suggest that anchors in the backfill at 15° inclination and length of 0.9<ce:italic>H</ce:italic> exhibit the highest reduction of pressure on the diaphragm wall.","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"26 1","pages":""},"PeriodicalIF":6.9,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867679","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}