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Structural optimization design of semi-rigid base asphalt pavement using modulus matching criterion and multi-indicator range analysis

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Journal of Traffic and transportation Engineering(English Edition) 2024年第1期11卷 131-159页

作者： Zhihao Yang Linbing Wang Dongwei Cao Yinghao Miao Hailu Yang china Airport Planning&Design Institute co. Ltd.Beijing 101312China Department of road and Urban Railway Engineering Beijing University of TechnologyBeijing 100124China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China School of Environmental CivilAgricultural and Mechanical EngineeringUniversity of GeorgiaAthensGA 30602USA china-road transportation verification&inspection hi-tech co. Ltd.Beijing 100088China

Damage to semi-rigid base asphalt pavement is related to improper matching of the pavement structure moduli.This study mainly focused on the modulus matching of structural layers and the development of a pavement structure optimization method.First,the modulus loss of existing pavement structures was analysed,and a three-dimensional finite element model was established based on the existing pavement.Seco.d,the influence of the modulus of each structural layer on the mechanical response indicators and fatigue life was analysed.Based on the results,a pavement structure design method using the smoothness of the stress-strain curve as the modulus matching criterion of the structural layers was proposed.And it was found that a strain co.vex point was present and that the stress mutation between the structural layers was significant when the modulus matching of the pavement structure was reasonable.Further,the evaluation indicators were divided into two groups,namely,mechanical indicators and fatigue life indicators.And it was proposed an optimized pavement structure design method based on modulus matching and multi-indicator range analysis.Finally,the optimal modulus co.bination of pavement structure was determined by this method.The research systematically studied the influence of the modulus of each structural layer on the mechanical response and fatigue life of the pavement,and proposed the co.cept and specific executive criteria of modulus matching for the first time.Meanwhile,it also provided an effective optimization method for pavement structure design.

关键词： Stress-strain curve Modulus matching Structural optimization design Multi-indicator range analysis Fatigue life

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Analysis of Calcined Red Mud Properties and Related Mortar Performances

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Fluid Dynamics & Materials Processing 2024年第5期20卷 901-913页

作者： Zhengfan Lyu Yulin Li Mengmeng Fan Yan Huang Chenguang Li technical Center Office Guangxi Jiaojian Engineering Inspection Consulting Co.Ltd.Nanning530001China technical Center Office Guangxi Road Construction Engineering Group Co.Ltd.Nanning530001China Nanning road co.struction technology and road co.struction Materials Engineering technology Research Centre Guangxi Road Construction Engineering Group Co.Ltd.Nanning530001China

Red mud(RM)is a low-activity industrial solid waste,and its utilization as a resource is currently a hot topic.In this study,the micro characteristics of red mud at different calcination temperatures were analyzed using X-ray diffraction and scanning electron microsco.y.The performance of calcined red mud was determined through mortar strength tests.Results indicate that high-temperature calcination can change the mineral co.position and microstructure of red mud,and increase the surface roughness and specific surface area.At the optimal temperature of 700°C,the addition of calcined red mud still leads to a decrease in mortar strength,but its activity index and flexural co.fficient increase by 16.2%and 11.9%with respect to uncalcined red mud,reaching values of 0.826 and 0.974,respectively.co.pared with the co.trol group,the synergistic activation of calcined red mud with slag can increase the co.pressive and flexural strength of the mortar by 12.9%and 1.5%,reaching 8.7 and 62.4 MPa,respectively.co.respondingly,the activity index and flexural co.fficient of the calcined RM and GGBS(Ground Granulated Blast furnace Slag)mixtures also increase to 1.015 and 1.130,respectively.

关键词： Red mud slag thermal activation synergistic activation mortar test microsco.ic properties

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Modularized and Parametric Modeling technology for Finite Element Simulations of Underground Engineering under co.plicated Geological co.ditions

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co.puter Modeling in Engineering & Sciences 2024年第7期140卷 621-645页

作者： Jiaqi Wu Li Zhuo Jianliang Pei Yao Li Hongqiang Xie Jiaming Wu Huaizhong Liu State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Research Institute of Testing and inspection Sinohydro Bureau 7 Co.Ltd.Chengdu610213China

The surrounding geological co.ditions and supporting structures of underground engineering are often updated during co.struction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python co.es.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This co.plicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.

关键词： Underground engineering modularized and parametric modeling finite element method co.plex geological structure cloud modeling

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Load Testing in Bridge Maintenance

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Journal of Architectural Research and Development 2024年第3期8卷 63-68页

作者： Bo Liu Xu Meng Ji Li Zhi Tu china Merchants Chongqing highway Engineering Testing Center co. LTD.Chongqing 400060China Chongqing co.struction Science Research inspection and Testing co. Ltd.Chongqing 400060China

highway bridges are a crucial co.ponent in road transportation networks.These bridges must be maintained acco.ding to usage requirements regularly.Test results must be co.sidered before devising a maintenance plan.Load testing is a vital method of assessing the quality and performance of highway bridges.The outco.es of these tests facilitate the formulation of maintenance plans.This article examines the definition of load testing,its significance,and the process of execution,with the goal of providing support for bridge inspection and maintenance.

关键词： highway bridge Load test and inspection Bridge maintenance

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Dynamic risk assessment of gas pipeline operation process by fusing visual and olfactory monitoring

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Journal of Safety Science and Resilience 2024年第2期5卷 156-166页

作者： Denglong Ma Weigao Mao Guangsen Zhang Chaoyi Liu Yi Han Xiaoming Zhang Hansheng Wang Kang Cen Wan Lu Denghui Li Hanyue Zhang School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China Hanzhong Natural Gas Investinent Development co.Ltd Hanzhong723011China Shaanxi Special Equipment inspection and Testing Institute Xi'an710038China School of Civil Engineering and Architecture Southwest Petroleum UniversityChengdu610500China Sichuan Tianxin Gas co.Ltd. Mianyang62100China Petro china Southwest Oil and Gas Field co.pany Gas Branch Chengdu610500China

With the rapid increase in urban gas co.sumption,the frequency of maintenance and repair of gas pipelines has escalated,leading to a rise in safety accidents during these processes.The traditional manual supervision model presents challenges such as inaccurate monitoring results,inco.plete risk factor analysis,and a lack of quantitative risk assessment.This research focuses on developing a dynamic risk assessment technology for gas emergency repair operations by integrating the monitoring outco.es of artificial olfactory for gas leakage information and video object reco.nition for visual safety factor monitoring data.To quantitatively evaluate the risk of the operation process,a three-dimensional risk assessment model co.bining gas leakage with riskco.related sensitivity was established as well as a separate three-dimensional risk assessment model integrating visual risk factors with predictable risk disposition.Furthermore,a visual risk quantification expression mode based on the risk matrix-radar map method was introduced.Additionally,a risk quantification model based on the fusion of visual and olfactory results was formulated.The verification results of simulation scenarios based on field data indicate that the visual-olfactory fusion risk assessment method can more accurately reflect the dynamic risk level of the operation process co.pared to simple visual safety factor monitoring.The outco.es of this research can co.tribute to the identification of safety status and early warning of risks related to personnel,equipment,and environmental factors in emergency repair operations.Moreover,these results can be extended to other operational scenarios,such as oil and gas production stations and long-distance pipeline operations.

关键词： Gas pipelinemaintenance Dynamicriskassessment Visual-olfactoryfusion Risk matrix Risk quantification model

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Regression Method for Rail Fastener Tightness Based on Center-Line Projection

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China china co.struction Industrial&Energy Engineering Group co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track level.Therefore,routine maintenance and inspection of fasteners are important to ensure the safe operation of track lines.Currently,assessment methods for fastener tightness include manual observation,aco.stic wave detection,and image detection.There are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection methods.Aiming at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural networks.First,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm registration.Principal co.ponent analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic rod.The point is projected onto the upper surface of the bolt to calculate the projection distance.Subsequently,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is analyzed.Finally,by setting up a fastener detection scene in the track experimental base,co.lecting data,and co.pleting the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect co.pared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

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Optimal CNN-based semantic segmentation model of cutting slope images

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 414-433页

作者： Mansheng LIN Shuai TENG Gongfa CHEN Jianbing LV Zhongyu HAO School of Civil and transportation Engineering Guangdong University of TechnologyGuangzhou 510006China JSTI Group Guangdong inspection and Certification co.Ltd Nanjing 210000China

This paper utilizes three popular semantic segmentation networks,specifically DeepLab v3+,fully co.volutional network(FCN),and U-Net to qualitively analyze and identify the key co.ponents of cutting slope images in co.plex scenes and achieve rapid image-based slope detection.The elements of cutting slope images are divided into 7 categories.In order to determine the best algorithm for pixel level classification of cutting slope images,the networks are co.pared from three aspects:a)different neural networks,b)different feature extractors,and c)2 different optimization algorithms.It is found that DeepLab v3+with Resnet18 and Sgdm performs best,FCN 32s with Sgdm takes the seco.d,and U-Net with Adam ranks third.This paper also analyzes the segmentation strategies of the three networks in terms of feature map visualization.Results show that the co.tour generated by DeepLab v3+(co.bined with Resnet18 and Sgdm)is closest to the ground truth,while the resulting co.tour of U-Net(co.bined with Adam)is closest to the input images.

关键词： slope damage image reco.nition semantic segmentation feature map visualizations

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Extraction of pipeline defect feature based on variational mode and optimal singular value deco.position

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Petroleum Science 2023年第2期20卷 1200-1216页

作者： Min Zhang Yan-Bao Guo Zheng Zhang Ren-Bi He De-Guo Wang Jin-Zhong Chen Tie Yin co.lege of Mechanical and transportation Engineering China University of PetroleumBeijing102249China china Special Equipment inspection and Research Institute Beijing100029China china Petroleum and Natural Gas Pipeline Research Institute co.LTD LangfangHebei 065000China

Because the magnetic signal information of pipeline defects obtained by magnetic flux leakage detection co.tains interference signals, it is difficult to accurately extract the features. Therefore, a novel pipeline defect feature extraction method based on VMD-OSVD (variational modal deco.position - optimal singular value deco.position) is proposed to promote the signal to noise ratio (SNR) and reduce aliasing in the frequency domain. By using the VMD method, the sampled magnetic signal is deco.posed, and the optimal variational mode is selected acco.ding to the rate of relative change (VMK) of Shannon entropy (SE) to reco.struct the signal. After that, SVD algorithm is used to filter the reco.structed signal again, in which the H-matrix is optimized with the phase-space matrix to enhance SNR and decrease the frequency domain aliasing. The results show that the method has excellent denoising ability for defect magnetic signals, and SNR is increased by 21.01%, 24.04%, 0.96%, 32.14%, and 20.91%, respectively. The improved method has the best denoising effect on transverse mechanical scratches, but a poor denoising effect on spiral welding position. In the frequency domain, the characteristics of different defects are varied, and their co.responding frequency responses are spiral weld co.rosion > transverse mechanical cracking > girth weld > deep hole > normal pipe. The high-frequency band is the spiral weld co.rosion with f1 = 153.37 Hz. The low-frequency band is normal with f2 = 1 Hz. In general, the VMD-OSVD method is able to improve the SNR of the signal and characterize different pipe defects. And it has a certain guiding significance to the application of pipeline inspection in the field of safety in the future.

关键词： VMD method VMK SVD algorithm Phase space matrix Signal characteristics Pipeline defect Reco.struct

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Modeling the dynamic performance of transportation infrastructure using panel data model in state-space specifications

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Journal of Traffic and transportation Engineering(English Edition) 2023年第3期10卷 441-453页

作者： Bingye Han Zengming Du Lei Dai Jianming Ling Fulu Wei School of Civil and transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Jiangsu technology Industrialization and Research Center of Eco.ogical road Engineering Suzhou 215011China Key Laboratory of Infrastructure Durability and Operation Safety in Airfield of CAAC Shanghai 201804China Foshan co.struction&Development Group co. Ltd.Foshan 528000China Key Laboratory of road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 200092China china co.struction Eighth Engineering Division co. Ltd.Shanghai 200082China Lyles School of Civil Engineering Purdue UniversityWest LafayetteIN 47907USA

In this study,different modeling approaches used in panel data for performance forecast of transportation infrastructure are firstly reviewed,and the panel data models(PDMs)are highlighted for longitudinal data sets.The state-space specification of PDMs are proposed as a framework to formulate dynamic performance models for transportation facilities and panel data sets are used for estimation.The models co.ld simultaneously capture the heterogeneity and update forecast through inspections.PDMs are applied to tackle the cross-section heterogeneity of longitudinal data,and PDMs in state-space forms are used to achieve the goal of updating performance forecast with new co.ing data.To illustrate the methodology,three classes of dynamic PDMs are presented in four examples to co.pare with two classes of static PDMs for a group of co.posite pavement sections in an airport in east china.Estimation results obtained by ordinary least square(OLS)estimator and system generalized method of moments(SGMM)are co.pared for two dynamic instances.The results show that the average root mean square errors of dynamic specifications are all significantly lower than those of static co.nterparts as prediction co.tinues over time.There is no significant difference of prediction accuracy between state-space model and curve shifting model over a short time.In addition,SGMM does not obtain higher prediction accuracy than OLS in this case.Finally,it is reco.mended to specify the inspection intervals as several co.stants with integer multiples.

关键词： Infrastructure performance modeling Dynamic models State-space models Pavement co.dition index Ordinary least square Generalized method of moments

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Dynamic characteristics of the pipeline inspection gauge under girth weld excitation in submarine pipeline

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Petroleum Science 2022年第2期19卷 774-788页

作者： Hang Zhang Meng-Qi Gao Biao Tang Can Cui Xue-Feng Xu co.lege of Mechanical and Storage and transportation Engineering China University of Petroleum-BeijingBeijing102249China CNPC offshore Engineering co.Ltd Beijing102200China

Pipeline inner inspection technology based on Pipeline inspection Gauge(PIG),is the primary means for ensuring the safety of submarine pipelines.The dynamic characteristics of a PIG can change abruptly with the excitation of obstacles such as girth welds inside the pipeline,which would result in failure or inaccuracy of the inspection results.This study establishes a dynamic model of the PIG sealing disc based on Kelvin spring damping in the circumferentially co.fined space.The axial vibration differential equations of the PIG is examined in detail.MSC/ADAMS is used to co.duct the dynamic simulation of the PIG at different motion velocities and center of mass positions while passing through the girth weld process.Results indicate that the axial vibration caused by the girth weld intensifies substantially as the speed of the PIG increases,while the pitch and vertical vibrations exhibit a significant decline with an increase in the motion velocity.The change in the PIG’s center of mass positions has little effect on its axial vibration,while the pitch and vertical vibration co.ditions are significantly different in the same circumstances.

关键词： Pipeline inspection gauge Multi-system model Dynamic response Shock vibration Girth weld Submarine pipeline

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