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China Ocean engineering 2024年第1期38卷 18-28页

作者： HU Ze-bo LIU Zhen LI Peng GUO Hai-yan WANG Shu-bing REN Xiao-hui HOU Hao WANG Ye-shuo College of civil engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China Qingdao Key Laboratory of Marine civil engineering Materials and Structures Qingdao 266590China College of engineering Ocean University of ChinaQingdao 266100China CHEC Dredging Co. LtdShanghai 200136China

A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined *** roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the *** risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference *** experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency *** addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser.

关键词： marine riser vortex-induced vibration side-by-side arrangement roughness interference effect

Quick Weighing of Passing Vehicles Using the Transfer-Learning-Enhanced Convolutional Neural Network

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2507-2524页

作者： Wangchen Yan Jinbao Yang Xin Luo College of civil engineering Xiangtan UniversityXiangtan411105China Energy&Environmental engineering Department China CEC Engineering CorporationChangsha410114China

Transfer learning could reduce the time and resources required by the training of new models and be therefore important for generalized applications of the trainedmachine learning *** this study,a transfer learningenhanced convolutional neural network(CNN)was proposed to identify the gross weight and the axle weight of moving vehicles on the *** proposed transfer learning-enhanced CNN model was expected to weigh different bridges based on a small amount of training datasets and provide high identification *** of all,a CNN algorithm for bridge weigh-in-motion(B-WIM)technology was proposed to identify the axle weight and the gross weight of the typical two-axle,three-axle,and five-axle vehicles as they crossed the bridge with different loading routes and ***,the pre-trained CNN model was transferred by fine-tuning to weigh themoving vehicle on another ***,the identification accuracy and the amount of training data required were compared between the two CNN *** showed that the pre-trained CNN model using transfer learning for B-WIM technology could be successfully used for the identification of the axle weight and the gross weight for moving vehicles on another bridge while reducing the training data by 63%.Moreover,the recognition accuracy of the pre-trained CNN model using transfer learning was comparable to that of the original model,showing its promising potentials in the actual applications.

关键词： Bridge weigh-in-motion transfer learning convolutional neural network

Phase deviation of semi-active suspension control and its compensation with inertial suspension

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Acta Mechanica Sinica 2024年第6期40卷 141-153页

作者： Yi Yang Changning Liu Long Chen Xiaoliang Zhang School of Automotive and Traffic engineering(Automotive engineering Research Institute) Jiangsu UniversityZhenjiang212013China Department of civil and Environmental engineering The Hong Kong Polytechnic UniversityHong KongChina

The performance of vehicle suspension is evaluated based on three conflicting indexes:body acceleration,suspension deflection,and dynamic tire load,which vary across different frequency *** suspension control strategy faces the challenge to strike a balance among these *** research analyzes the fundamental mechanism of control phase deviation effects on skyhook damper control,groundhook damper control,and acceleration drive damper *** the perspective of complex domain mechanical impedance with the support of the inertial suspension,a structure-based compensation approach is proposed to address for the control phase *** simulation analysis demonstrates that the coordination of inertial suspension structure and control strategy can effectively enhance the comprehensive suspension performance across entire frequency ***,a semi-active inertial suspension bench is *** experimental results indicate that the suspension with the semi-active inertial suspension has outstanding vibration isolation ability,and enhances the suspension performance at ride comfort,suspension deflection,and road friendly significantly.

关键词： Vibration isolation Vibration control Phase deviation Control compensation Semi-active suspension

Corrosion behavior and protection mechanism of carbon steel coated with ethylene chlorotrifluoroethylene(ECTFE)

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第6期25卷 502-515页

作者： Peihu SHEN Jun WEN Biqin DONG Hedong LI Minjia WANG School of civil engineering and Architecture Zhejiang Sci-Tech UniversityHangzhou310018China College of civil and Transportation engineering Shenzhen UniversityShenzhen518061China Zhejiang Research Institute of Chemical Industry Co. Ltd.Hangzhou310023China

Ethylene chlorotrifluoroethylene(ECTFE)coating was applied to the surface of carbon steel through electrostatic spraying and low-temperature heat *** morphology and structure of the coating were analyzed using various characterization *** electrochemical data of the coated steel soaked in 3.5%(mass fraction)NaCl solution for 90 d at different periods were also *** findings indicate that the outer surface of the coating remains structurally stable before and after soaking.F can diffuse into the steel substrate,facilitating the bonding between the coating and the steel substrate,but the free F also induces a weakening effect on the crystalline *** to the thickness of the coating edge and the susceptibility to infiltration of the corrosive medium,under-film micro-zone corrosion occurs at a slow *** soaking for 90 d,the impedance modulus measures approximately 10^(4)Ω·cm^(2),and the open circuit potential(OCP)is−0.61 *** self-corrosion current density is 1.13×10^(−6)A/cm^(2),resulting in a calculated coating protection rate of 99.29%.In summary,despite edge corrosion occurring,the ECTFE coating provides excellent corrosion protection.

关键词： Coating Fluorine resin Edge corrosion Corrosive behavior Electrochemical performance

Seismic responses of an intensively constructed metro station-passageway-shaft structure system

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Frontiers of Structural and civil engineering 2024年第5期18卷 760-775页

作者： Ruohan LI Yong YUAN Hong CHEN Xinxing LI Emilio BILOTTA Department of Geotechnical engineering Tongji UniversityShanghai 200092China Department of civil Architectural and Environmental EngineeringUniversity of Naples Federico IINaples 80125Italy State Key Laboratory of Disaster Reduction in civil engineering Tongji UniversityShanghai 200092China Shanghai Tunnel engineering&Rail Transit Design and Research Institute Shanghai 200235China

Intensive construction methods offer benefits for metro station development,yet they present challenges for seismic design due to the spatially asymmetric configuration of passageway-shaft *** this study,a detailed numerical model of a station-passageway-shaft structure system built using intensive construction methods was developed and the deformation and damage modes under seismic loadings were *** results indicate that inconsistent deformation between the shaft and the station generates interaction through the connecting passageway,leading to damage near the opening of the station structure and both ends of the connecting passageway Damage is more severe under longitudinal *** with the opening plan that spans four segments,the opening plan that spans five segments exacerbates the overall degree of damage to the structure *** transverse excitation,the presence of interior structures intensifies the damage to the station and connecting passageway,while with such internal structure in place the impact is relatively minor under longitudinal *** with steel segments near the station opening can appreciably attenuate the *** contrast,introducing flexible joints at both ends of the connecting passageway intensifies the ***,reinforcement using steel segments emerges as an optimal seismic mitigation strategy.

关键词： earthquake intensive construction metro station numerical simulation

Numerical and analytical studies on the coupling effects of unloading and cutterhead vibration on tunnel face in dry sandy ground

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Underground Space 2024年第5期18卷 256-272页

作者： Junzuo He Shaoming Liao Mengbo Liu Motoi Iwanami Yanqing Men Department of Geotechnical engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Road and Traffic engineering Ministry of EducationTongji UniversityShanghai 200092China Department of civil and Environmental engineering Waseda UniversityTokyo 169-0072Japan Jinan Rail Transit Group Co. Ltd.Jinan 250014China

When tunnelling in difficult ground conditions,shield machine would inevitably produce significant ground loss and vibration,which may disturb the ground ahead of the tunnel *** this paper,discrete element models calibrated by model tests were established to investigate the response of tunnel face under the coupling effects of unloading and cutterhead *** results show that the friction angle reduction under cyclic loading and vibration attenuation in the sandy ground are significant and can be estimated by the fitted exponential *** cutterhead vibration,the tunnel face stability is undermined and the limit support pressure(LSP)increases to 1.4 times as that in the static case with the growth of frequency and ***,the loosening zone becomes wider and the arching effect is weakened with the reduction of peak horizontal stress and the increase of vertical stress above the *** on the numerical results,a pseudo-static method was introduced into the limit equilibrium analysis of the wedge-prism model for calculating the LSP under *** an error rate less than 5.2%,the proposed analytical method is well *** analytical calculation reveals that the LSP would increase with the growth of vibration amplitude,vibration frequency and covered depth but decrease with the increase of friction *** study can not only lay a solid foundation for the further investigation of ground loss,ground water and soft-hard heterogeneous ground under cutterhead vibration,but also provide meaningful references for the control of environmental disturbance in practice.

关键词： Cutterhead vibration Tunnel face stability Discrete element method Pseudo-static method

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

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Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： Zhiqiang Fan Zhihe Jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the Laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

Model-based investigation on building thermal mass utilization and flexibility enhancement of air conditioning loads

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Building Simulation 2024年第8期17卷 1289-1308页

作者： Yue Sun Tianyi Zhao Shan Lyu Institute of Building Energy School of Infrastructure EngineeringDalian University of TechnologyDalian116024China School of civil engineering Chongqing UniversityChongqing 400045China

Building air conditioning systems(ACs)can contribute to the stable operation of power grids by participating in peak load shaving programs,but the participants need a fast and accurate zone temperature prediction model,e.g.,the detailed room thermal-resistance(RC)model,to improve peak shaving effect and avoid obvious thermal ***,when applying the detailed room RC model to multi-zone buildings,conventional studies mostly consider the heat transfer among neighboring rooms,which contributes little to the prediction accuracy improvement,but leads to complicated model structure and heavy ***,a distributed RC model is developed for multi-zone buildings in this *** to conventional models,the proposed model considers the total heat transfer between the building and the air,and ignores the heat transfer among indoor air in neighboring rooms through internal walls with heavy thermal mass,thereby having comparable temperature prediction accuracy,simpler structure,and stronger *** on the model,the effectiveness of passive pre-cooling strategies in reducing the air conditioning loads during peak periods is *** indicate that the thermal insulation performance of opaque building envelope is quite important to the flexibility enhancement of air conditioning *** an uninsulated building envelope,passive pre-cooling is useless for the peak load *** comparison,well insulated opaque building envelope enables the building thermal mass to be utilized through passive pre-cooling,which leads to the air conditioning loads during peak periods being further reduced by about 12%.

关键词： RC model passive pre-cooling internal thermal mass building energy flexibility

Sensitivity analyses of random cave groups on karst tunnel stability based on water–rock interaction using a novel contact dynamic method

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Underground Space 2024年第5期18卷 162-186页

作者： Chengzhi Xia Zhenming Shi Huanjia Kou Shaoqiang Meng Maomao Liu College of civil engineering Tongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground engineering of Ministry of Education Tongji UniversityShanghai 200092China

This paper concentrates on the sensitivity and dynamic simulation of randomly distributed karst cave groups on tunnel stability and connectivity extended ratio based on water–rock interaction using a novel contact dynamic method(CDM).The concept of karst cave group connectivity extended ratio during tunneling and water inrush is *** effects of cave shape and spatial distribution on Qiyueshan tunnel are *** deformation and damage index,and connectivity extended ratio with uniform random karst cave groups are *** results demonstrate that the connectivity extended ratio is verified as a crucial judgment in predicting the safe distance and assessing the stability of the tunnel with the karst cave *** model captures the fracture propagation and contact behavior of rock mass,surface flow,as well as the bidirectional water–rock interaction during the water inrush of Qiyueshan tunnel with multiple caves.A larger cave radius and smaller minimum distance between the cave and tunnel increase the deformation and damage index of the surrounding *** the cave radius and cave area ratio increase,the failure pattern shifts from overall to local *** findings potentially have broad applications in various surface and subsurface scenarios involving water–rock interactions.

关键词： Karst tunnel stability Contact dynamic method Connectivity extended ratio Karst cave groups Qiyueshan tunnel Water-rock interaction

A bounding surface visco-plasticity model considering generalized spacing ratio of soils

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Journal of Rock Mechanics and Geotechnical engineering 2024年第5期16卷 1832-1846页

作者： Xiaosen Kang Hongjian Liao Qiangbing Huang Jianbing Peng Department of Geological engineering Chang’an UniversityXi’an710054China Department of civil engineering Xi’an Jiaotong UniversityXi’an710049China

The non-unique critical state of soils with time-dependent behaviors is a significant issue in geotechnical engineering ***,previous bounding surface plasticity models cannot predict accurately the non-unique critical state of soils,because the distance between the compression line and critical state line charged by strain-rate effect is basically *** fill this gap,a generalized spacing ratio of soils is defined in the elasto-viscoplastic framework,and a bounding surface visco-plasticity model is formulated and verified,which can consider the generalized spacing ***,the generalized spacing ratio of soils reflects the distance between the compression line and the critical state line of soils with time-dependent ***,the generalized spacing ratio is introduced into an improved anisotropic bounding surface.A new expression of the visco-plastic multiplier is derived by solving the consistency equation of an anisotropic bounding *** the expression,a strain rate index is proposed to account for the strain-rate effect on visco-plastic strain increment,and a visco-plastic hardening modulus is derived to predict the visco-plastic response of soils in overconsolidation *** model is then verified through constant strain rate tests and creep ***,it can capture the non-unique critical states of soils with time-dependent behaviors due to the generalized spacing ratio and the creep rupture of soils due to the visco-plastic multiplier that considers the stress ratio and visco-plastic strain rate.

关键词： Soil Constitutive model Visco-plastic behavior Strain rate Creep Anisotropic