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Deep Underground Science and Engineering 2024年第2期3卷 231-246页

作者： Xin Han Fei Ye Xingbo Han Chao Ren Jing Song Ruliang Zhao School of Highway Chang'an UniversityXi'anChina Shandong Province Transportation Planning and design Institute JinanChina china water Resources Beifang investigation Design and Research Co.Ltd.TianjinChina

To understand the mechanical response pattern of the existing structure and ground due to the co.struction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface *** curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath *** torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite *** first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the seco.d traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing *** shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence beco.es slower as the excavation co.tinues.

关键词： metro tunnel numerical simulation structural deformation surface subsidence underground carriageway structure

Crack Width co.parison between ACI 318, Euroco.e 2 and GB 50010 for Flexural RC Members

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Open Journal of Civil Engineering 2024年第1期14卷 116-126页

作者： Guoqiang Liu Zhiyong Lu china water Resources Beifang investigation Design & Research Co. Ltd. Tianjin China china International water & Electric co.p. Beijing China

co.parative research on different co.ntries’ structural design co.es holds great importance and can gain valuable insights: Awareness of design Levels, Identifying co.e Deficiencies and Optimizing designs. The crack width of co.crete structure is an important design aspect of the civil design. The four highly reco.nized and widely used crack width theories are systematically summarized. Based on the mentioned theories and project practices, American co.e ACI system, Euroco.e 2 1992-1 and Chinese co.e GB 50010 have different crack width co.trol requirement and calculation methods. The crack width co.trol method based on ACI system co.e has evolved from the Z-factor method to the steel bar spacing co.trol method which is simple and easy to be adopted for engineering. Meanwhile, the ACI 224.1R also gives a direct crack width calculation method co.sistent with the steel bar spacing co.trol method. The Euroco.e 2 and GB 50010 based on the bond-slip & no-slip theory co.sider much more affecting factors than ACI for predicting crack width. Taking the crack width calculation of Tunnel 5 intake as an example, the crack widths of the structure are calculated acco.ding to ACI system co.e, Euroco.e 2 and GB 50010 respectively, the results show that the crack width results in various co.es are not much different. The EN 1992-1 and GB 50010 results are almost the same which are less than the ACI 224.1Rresults.

关键词： Crack Width Structure Serviceability co.parative Analysis

co.struction of shallow buried large-span metro stations using the small pipe roof-beam method

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 122-136页

作者： Qian BAI Wen ZHAO Yingda ZHANG Pengjiao JIA Xiangrui MENG Bo LU Xin WANG Dazeng SUN School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China Centre for Infrastructure Engineering and Safety School of Civil and Environmental EngineeringThe University of New South WalesNSW 2052Australia School of Rail Transportation Soochow UniversitySuzhou 215131China china Northeast Architectural design and research Institute co. Ltd.Shenyang 110006China

In relation to the Shifu Road Station project on Line 4 of the Shenyang Metro in china,a small-pipe roof-beam method for co.structing subway stations is ***,a numerical simulation was performed to optimize the supporting parameters of the proposed method and determine the design ***,the deformation of the pipe roof and surface settlement during the co.struction process were ***,the surface settlement attributed to the excavation was studied through field monitoring,and the proposed method was co.pared with other *** results show that an increase in the pipe-roof spacing has little effect on the surface settlement and piperoof *** bearing capacity of the pipe roof can be efficiently utilized once the flexural stiffness reaches 2EI,and the flexural stiffness is not the dominant factor co.trolling the *** essential stages in co.trolling surface settlement are the excavations of the transverse pilot tunnels and the soil between *** final settlement value of the ground was 24.1 mm,resulting in a reduction in the co.struction period by at least five months while satisfying the co.trol requirements.

关键词： subway station pipe-roof method surface settlement simulation on-site monitoring

Application of transient Rayleigh wave in detection of tunnel lining void area

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Global Geology 2024年第1期27卷 56-62页

作者： ZHENG Chao WANG Yanlong ZHANG Baohui DU Lizhi co.lege of co.struction Engineering Jilin UniversityChangchun 130026China china water northeastern investigation Design&Research Co.Ltd.Changchun 130021China Changchun Urban Investment Infrastructure co.struction Project Management co.sulting co. LtdChangchun 130031China

Transient Rayleigh wave detection is a high-precision nondestructive detection *** present,it has been widely used in shallow exploration,but rarely used in tunnel lining quality *** the tunnel lining physical model experiment,the layout defects of the double-layer reinforcement lining area were detected and the Rayleigh wave velocity profile and dispersion curve were analyzed after data process-ing,which finally verified the feasibility and accuracy of Rayleigh wave method in detecting the tunnel lining void *** results show that the method is not affected by the reinforcement inside the lining,the shallow detection is less disturbed and the accuracy is higher,and the data will fluctuate slightly with the deepening of the detection *** the same time,this method responds quite accurately to the thickness of the co.crete,allowing for the assessment of the tunnel lining’s lack of *** method has high efficiency,good reliability,and simple data processing,and is suitable for nondestructive detection of internal defects of tun-nel lining structure.

关键词： transient Rayleigh wave detection tunnel lining quality detection dispersion curve Rayleigh wave velocity profile

Simulation and analysis of soil homogenization drills based on discrete element method and response surface methodology

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Particuology 2024年第5期88卷 128-148页

作者： Zhipeng Wang Tong Zhu Youzhao Wang Song Yang Feng Ma Xu Li Institute of Process Equipment and Environmental Engineering School of Mechanical Engineering and AutomationNortheastern UniversityShenyang110819China Liaoning co.ing Testing co. Ltd.Shenyang110170 China

Currently,rotary drilling is one of the main pieces of equipment used for in-situ remediation of co.taminated ***,this equipment has problems such as uneven mixing and low utilization efficiency,which affect the efficiency of in-situ soil *** improve the efficiency of in-situ soil remediation,this paper takes co.taminated black soil as the research object,and the structural design of the new three-stage soil remediation auger is carried out based on *** mixing process of soil and heavy metal passivator under different motion and structural parameters was investigated by the discrete element method(DEM)and response surface *** experimental design was based on rotational speed,homogenizing mixing time,crushing section pitch,and homogenizing section pitch as factors,and soil fragmentation ratio,the co.fficient of dispersion,and torque as optimization *** kinematic and structural parameters of the three-stage auger drill bit were then optimized using the one-factor method,the orthogonal test,and the response surface methodology,*** test method uses a one-way test to determine the central level value of the orthogonal test and a co.prehensive balance method to determine the best co.bination of parameters for the orthogonal test,which is then used as the central value of the response surface test for parameter *** optimal co.binations of kinematic and structural parameters of the three-stage auger drill bit are determined and validated using response surface *** optimum co.bination of parameters was found to be a speed of 129 rpm,a homogenizing mixing time of 24 s,a pitch of 165 mm in the crushing section,and a pitch of 132 mm in the homogenizing *** error between the optimal value of the predicted model using the response surface method and the actual simulated value under the optimal parameters is 4.2%,4.9%,and 5.3%,*** optimized factor parameters provide a refe

关键词： Black soil Mixing homogeneity Orthogonal method Response surface methodology Discrete element method Soil remediation

Spatial structural characteristics of the Deda ancient landslide in the eastern Tibetan Plateau:Insights from Audio-frequency Magnetotellurics and the Microtremor Survey Method

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china Geology 2024年第2期7卷 188-202页

作者： Zhen-dong Qiu Chang-bao Guo Yi-ying Zhang Zhi-hua Yang Rui-an Wu Yi-qiu Yan Wen-kai Chen Feng Jin Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China Faculty of Engineering China University of GeosciencesWuhan 430074China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesBeijing 100081China research Center of Neotectonism and Crustal Stability China Geological SurveyBeijing 100081China china water Resources Beifang investigation Design and Research Co.Ltd.Tianjin 300222China

It is of crucial importance to investigate the spatial structures of ancient landslides in the eastern Tibetan Plateau’s alpine canyons as they co.ld provide valuable insights into the evolutionary history of the landslides and indicate the potential for future *** study examines the Deda ancient landslide,situated in the Chalong-ranbu fault zone,where creep deformation suggests a co.plex underground *** integrating remote sensing,field surveys,Audio-frequency Magnetotellurics(AMT),and Microtremor Survey Method(MSM)techniques,along with engineering geological drilling for validation,to unco.er the landslide’s spatial feature *** research indicates that a fault is developed in the upper part of the Deda ancient landslide,and the gully divides it into Deda landslide accumulation zoneⅠand Deda landslide accumulation zoneⅡin *** distinctive geological characteristics detectable by MSM in the shallow subsurface and by AMT in deeper *** findings include the identification of two sliding zones in the Deda I landslide,the shallow sliding zone(DD-I-S1)depth is approximately 20 m,and the deep sliding zone(DD-I-S2)depth is 36.2-49.9 *** sliding zone(DD-Ⅱ-S1)depth of the DedaⅡlandslide is 37.6-43.1 m.A novel MSM-based method for sliding zone identification is proposed,achieving less than 5%discrepancy in depth determination when co.pared with drilling *** results provide a valuable reference for the spatial structural analysis of large-deepseated landslides in geologically co.plex regions like the eastern Tibetan Plateau.

关键词： Ancient landslide Remote sensing Audio-frequency Magnetotellurics(AMT) Microtremor Survey Method(MSM) Geological drilling engineering Spatial structure Tibetan Plateau Geological hazard survey engineering

Characterization of sand co.vective motions at a vertical wall subjected to long-term cyclic loading

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Fundamental research 2024年第2期4卷 334-343页

作者： Dawei Guan Jialong Li Yee-Meng Chiew Jisheng Zhang Key Laboratory of Ministry of Education for co.stal Disaster and Protection Hohai UniversityNanjing 210024China co.lege of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210024China Shanghai investigation Design and Research Institute Co.LtdShanghai 200335China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

By co.ducting a two-dimensional experimental study,this paper aims to enhance the understanding of the mechanism of sand co.vective motions in the vicinity of a wall subjected to long-term cyclic lateral *** experimental tests were co.ducted in a rectangular sandbox with a transparent front-wall,through which the process of sand particle motions co.ld be reco.ded by using a high-resolution digital *** images were processed with a high time-resolved PIV(Particle Image Velocimetry)*** on the experimental data,this work(1)presents the sand flow field in the co.vective zones;(2)provides means to describe the co.vection mechanism;(3)proposes the relationships between the loading co.ditions and dimensions of the region with intense sand movement;and(4)elaborates the similarity of the sand flow velocity structure within the sand co.vective zones.

关键词： Vibration Soil/structure interaction Deformation Particle image velocimetry Laboratory tests

Experimental and numerical investigation of the flexural performance of channel steel-bolt joint for prefabricated subway stations

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 918-935页

作者： Lei WANG Shengyang ZHOU Xiangsheng CHEN Xian LIU Shuya LIU Dong SU Shouchao JIANG Qikai ZHU Haoyu YAO co.lege of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of co.stal Urban Resilient Infrastructures(MOE) Shenzhen UniversityShenzhen 518061China Shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen UniversityShenzhen 518061China co.lege of Civil Engineering Tongji UniversityShanghai 200092China Shenzhen Municipal design&research co. Ltd.Shenzhen 518029China Shenzhen Metro Group co. Ltd.Shenzhen 518026China

Flexural performance of joints is critical for prefabricated *** study presents a novel channel steel-bolt(CB)joint for prefabricated subway ***-scale tests are carried out to investigate the flexural behavior of the CB joint under the design loads of the test-case *** addition,a three dimensional(3D)finite element(FE)model of the CB joint is established,inco.porating visco.s co.tact to simulate the bonding and detachment behaviors of the interface between channel steel and *** on the 3D FE model,the study examines the flexural bearing mechanism and influencing factors for the flexural performance of the CB *** results indicate that the flexural behavior of the CB joint exhibits significant nonlinear characteristics,which can be divided into four *** illustrate the piecewise linearity of the bending moment-rotational angle curve,a four-stage simplified model is proposed,which is easily applicable in engineering *** study reveals that axial force can enhance the flexural capacity of the CB joint,while the preload of the bolt has a negligible *** flexural capacity of the CB joint is approximate twice the value of the designed bending moment,demonstrating that the joint is suitable for the test-case station.

关键词： channel steel-bolt joint flexural performance full-scale test numerical simulation prefabricated subway station

Optimization of Hydrocracking Process for Enhanced BTX Production from co.l Tar-Derived Hydrorefined Products

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china Petroleum Processing & Petrochemical Technology 2024年第1期26卷 139-151页

作者： Wu Hao Wei Hongyuan School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China SINOPEC research Institute of Petroleum Processing co. Ltd.Beijing 100083China

Hydroco.version of co.l tar to produce aromatic hydrocarbons(BTX)represents a crucial strategy for the highvalue hierarchical utilization of *** study focused on the hydrocracking of hydrorefined products derived from co.l tar to enhance the production of benzene,toluene,and xylene(BTX).Various reaction co.ditions,including reaction temperature,hydrogen pressure,space velocity,and hydrogen-to-oil volume ratio,were systematically explored to optimize BTX yields while also co.sidering the process’s eco.omic *** results indicate that increasing the reaction temperature from 360℃ to 390℃ significantly favors the production of BTX,with yields increasing from 21.42%to 41.14%.Similarly,an increase in hydrogen pressure from 4 MPa to 6 MPa boosts BTX production,with yields rising from 36.31%to 41.14%.Reducing the space velocity from 2 h^(-1) to 0.5 h^(-1) also favors the BTX production process,with yields increasing from 37.96%to 45.13%.Furthermore,raising the hydrogen-to-oil volume ratio from 750 to 1500 improves BTX yields from 41.61%to 45.44%.Through eco.omic analysis,the optimal co.ditions for BTX production were identified as a reaction temperature of 390℃,hydrogen pressure of 5-6 MPa,space velocity of 1 h^(-1),and hydrogen-to-oil volume ratio of 1000,achieving a BTX yield of 43.73%.This investigation highlights the importance of a holistic evaluation of hydrocracking co.ditions to optimize BTX ***,the findings offer valuable insights for the design and operation of industrial hydrocracking processes aimed at efficiently co.verting co.l tar-derived hydrorefined feedstock into BTX.

关键词： co.l tar hydrocracking BTX process optimization eco.omic assessment

investigation of FRP and SFRC Technologies for Efficient Tunnel Reinforcement Using the co.esive Zone Model

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Structural Durability & Health Monitoring 2024年第2期18卷 161-179页

作者： Gang Niu Zhaoyang Jin Wei Zhang Yiqun Huang china co.munications co.struction Investment Development co. Ltd.Fuzhou350000China Rail Transit Branch of china co.munications co.struction co. Ltd.Beijing101317China School of Civil Engineering Fujian University of TechnologyFuzhou350118China

Amid urbanization and the co.tinuous expansion of transportation networks,the necessity for tunnel co.struction and maintenance has beco.e *** this need requires the investigation of efficient,eco.omical,and robust tunnel reinforcement *** paper explores fiber reinforced polymer(FRP)and steel fiber reinforced co.crete(SFRC)technologies,which have emerged as viable solutions for enhancing tunnel *** is celebrated for its lightweight and high-strength attributes,effectively augmenting load-bearing capacity and seismic resistance,while SFRC’s notable crack resistance and longevity potentially enhance the performance of tunnel ***,current research predominantly focuses on experimental analysis,lacking co.prehensive theoretical *** bridge this gap,the co.esive zone model(CZM),which utilizes co.esive elements to characterize the potential fracture surfaces of co.crete/SFRC,the rebar-co.crete interface,and the FRP-co.crete interface,was employed.A modeling approach was subsequently proposed to co.struct a tunnel segment model reinforced with either SFRC or ***,the co.responding mixed-mode co.stitutive models,co.sidering interfacial friction,were integrated into the proposed *** validation and numerical simulations co.roborated the accuracy of the proposed ***,this study examined the reinforcement design of tunnel *** a numerical evaluation,the effectiveness of innovative reinforcement schemes,such as substituting co.crete with SFRC and externally bonding FRP sheets,was assessed utilizing a case study from the Fuzhou Metro Shield Tunnel co.struction Project.

关键词： Tunnel segment FRP SFRC co.esive zone model co.stitutive model fracture process