Transport Of Multi-Phase Multi-Component Fluids In The Shallow Subsurface Influenced By Soil And Surface Boundary Conditions: Experimental And Numerical Study With Application To Natural Gas Leakage,
2024
Southern Methodist University
Transport Of Multi-Phase Multi-Component Fluids In The Shallow Subsurface Influenced By Soil And Surface Boundary Conditions: Experimental And Numerical Study With Application To Natural Gas Leakage, Navodi Jayarathne
Civil and Environmental Engineering Theses and Dissertations
With the increased use of Natural Gas (NG) as a source of fuel, underground leak-related events are increasingly reported, and some are fatal. Subsurface migration and development up to flammable limits are highly dependent on leak characteristics, soil, atmospheric variables, and other surface and subsurface structural complexities. Although few studies have characterized the transient behavior of leaked NG in the shallow subsurface, the underlying mechanisms and their interactions are not well understood, which prevents prediction of the impact of environmental and operating conditions on gas migration. The study conducted a series of field scale-controlled release experiments and numerical simulations to …
Image Filtering To Improve Maize Tassel Detection Accuracy
Using Machine Learning Algorithms,
2024
University of Nebraska-Lincoln
Image Filtering To Improve Maize Tassel Detection Accuracy Using Machine Learning Algorithms, Eric Rodene, Gayara Demini Fernando, Ved Piyush, Yufeng Ge, James C. Schnable, Souparno Ghosh, Jinliang Yang
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Unmanned aerial vehicle (UAV)-based imagery has become widely used to collect timeseries agronomic data, which are then incorporated into plant breeding programs to enhance crop improvements. To make efficient analysis possible, in this study, by leveraging an aerial photography dataset for a field trial of 233 different inbred lines from the maize diversity panel, we developed machine learning methods for obtaining automated tassel counts at the plot level. We employed both an object-based counting-by-detection (CBD) approach and a density-based counting-by-regression (CBR) approach. Using an image segmentation method that removes most of the pixels not associated with the plant tassels, the …
Key Construction Techniques For Incremental Launching And High Falling Beam Of Long‑Span Simply Supported Steel Box Girder,
2024
Mechanization Engineering Co .， Ltd.， China Railway No . 5 Engineering Group Co .， Ltd.， Hengyang ， Hunan 421000 ， China
Key Construction Techniques For Incremental Launching And High Falling Beam Of Long‑Span Simply Supported Steel Box Girder, Wu Yanbin, Lyu Maofeng, Yin Qijia, Yu Guanqiu
Journal of China & Foreign Highway
Based on the overpass project over Beijing-Hong Kong-Macao Expressway on Changsha Pan-Pan Road，this paper proposed a construction method of large-slope walking-type incremental launching and high falling beam of steel box girder given the difficulties in busy traffic under the bridge，large pushing slope，and great total height of falling beam.After the steel box girder assembly was completed，some bridge deck ancillary facilities were constructed in advance in the preassembly yard and the weight was allocated.The steel box girder was pushed synchronously，thereby reducing the aerial work on the bridge in the later stage.During the incremental launching construction of the steel box girder above the …
Different Forms Of Nano‑Sio2 In Emulsified Asphalt And Their Effects On Emulsion Storage Stability,
2024
Sixth Engineering Branch of CCCC Fourth Highway Engineering Co .， Ltd.， Tianjin 301700 ， China
Different Forms Of Nano‑Sio2 In Emulsified Asphalt And Their Effects On Emulsion Storage Stability, Ji Chao, Cao Yuanhao, Li Zhigang
Journal of China & Foreign Highway
The insufficient storage performance of emulsified asphalt has always been a problem affecting its application，and there have been studies in China on nano-SiO2 particles as additives to improve the stability of emulsified asphalt，but the effect is not obvious.Based on the principle of Pickering emulsion，nano-SiO2 with surface modification was used as an emulsifier to directly emulsify matrix asphalt，and whether its stability improvement effect on emulsified asphalt is better than nano-SiO2 as a modified additive was explored.Firstly，three emulsified asphalt were prepared，namely ordinary modified emulsified asphalt A，emulsified asphalt B with nano-SiO2 as a modified additive，and emulsified asphalt C based on the new nano-SiO2 …
Study On Test Methods Of Wheel Sticking‑Free Emulsified Asphalt,
2024
Research Institute of Highway Ministry of Transport ， Beijing 100088 ， China ;Key Laboratory of Transport Industry of Road Structure and Material ， Beijing 100088 ， China
Study On Test Methods Of Wheel Sticking‑Free Emulsified Asphalt, Wang Peng, Qin Yongchun, Wang Jie, Xiong Weiming, Chang Rong, Fu Chongfeng, Feng Guoli
Journal of China & Foreign Highway
The wheel sticking-free emulsified asphalt is a key material to solve the wheel sticking problem in the process of asphalt pavement construction，with the wheel sticking-free effect as the core index.The accurate evaluation of the wheel sticking-free effect is important for the popularization and application of wheel sticking-free emulsified asphalt.Based on the research results in China and abroad，two test methods for wheel sticking-free effects （counterweight method and indenter method ） were innovatively proposed，and the wheel sticking-free effects of various emulsified asphalt were evaluated.The test results show that the two test methods can accurately evaluate the wheel sticking-free performance of emulsified asphalt，and …
Study On Mobilization Rate Of Rap Aged Asphalt Based On Ftir,
2024
Jinhua Highway and Transportation Management Center ， Jinhua ， Zhejiang 321000 ， China
Study On Mobilization Rate Of Rap Aged Asphalt Based On Ftir, Zou Xiaoyong, Li Ning, Wu Wenxiu, Wang Xin, Xu Xiaohe
Journal of China & Foreign Highway
During the preparation of the recycled asphalt mixture，part of the aged asphalt is first transferred from the surface of the recycled material to the new aggregate and then diffused and fused with the new asphalt，in which the percentage of transferred aged asphalt plays a key role in the final regeneration effect.In order to study the degree of transfer of aged asphalt in reclaimed asphalt pavement （RAP ），the mobilization rate （RMR） was calculated and analyzed based on the Fourier transform infrared spectroscopy （FTIR ）.The AC-13 graded recycled asphalt mixture was mixed and sieved to separate the new aggregate and RAP.The recycled …
Deflection Variation Rule Of Main Girder For A Concrete Cable‑Stayed Bridge Based On Combined Static And Dynamic Modification,
2024
School of Civil Engineering ， Southwest Jiaotong University ， Chengdu ， Sichuan 610031 ，China ;National Engineering and Research Center for Mountainous Highways ， Chongqing 400000 ， China
Deflection Variation Rule Of Main Girder For A Concrete Cable‑Stayed Bridge Based On Combined Static And Dynamic Modification, Li Qi, Qi D Ongchun, Yang Hu, Zhao Zhiguo
Journal of China & Foreign Highway
In order to solve the problem of continuous downward deflection of the main girder for a concrete cable-stayed bridge during its service life，the deflection variation of the main girder for a long-span concrete cable-stayed bridge during its service was analyzed based on the modified model.A dual-objective optimization problem was constructed by using the combined static and dynamic finite element model modification method and was solved by the non-dominated sorting genetic algorithm （NSGA- Ⅱ）.The Pareto optimal solution set was obtained，and the coordinated optimal solution was found in the Pareto optimal solution set，so as to modify the finite element model.The calculated values …
Construction Technology Of Reactive Powder Concrete Prestressed Box Girder,
2024
China Railway Urban Construction Group Corporation Limited ， Changsha ， Hunan 410208 ， China
Construction Technology Of Reactive Powder Concrete Prestressed Box Girder, Wang Xiaojie
Journal of China & Foreign Highway
At present，high-strength and high-performance concrete has some disadvantages，such as low flexural strength，large brittleness，and poor volume stability.Reactive powder concrete （RPC ） is a new type of material，which has good mechanical properties and high impermeability.It can reduce the amount of concrete to a greater extent and reduce the weight of the structure，achieving the purpose of safety，reliability，and cost saving.This paper applied RPC to highway prestressed box girder.Through the innovation and optimization of mix ratio，the change in traditional transportation technology，and curing technology research of steam curing shed，it effectively shortens the pouring time of RPC，ensuring the pouring quality and strength.
Fragilit Y Analysis Of Continuous Rigid Frame Bridge With High Piers And Long Span Subjected To Near‑Field Earthquakes,
2024
Gansu Luqiao Highway Investment Co .， Ltd.， Lanzhou ， Gansu 730050 ， China
Fragilit Y Analysis Of Continuous Rigid Frame Bridge With High Piers And Long Span Subjected To Near‑Field Earthquakes, Sun Yongjiang
Journal of China & Foreign Highway
Near-field earthquakes are more destructive to the continuous rigid frame bridge with high piers and long span.Based on a new-built continuous rigid frame bridge with high piers and long span，considering the seismic demand probability of bridges under near-field earthquakes，this paper utilized OpenSees to analyze the time history of the bridge.The structure response of the bridge under near-field earthquakes was obtained by the nephogram method，and the vulnerability of the bridge under earthquake was analyzed based on the curvature demand probability model of the structure.The results show that the probability response of curvature demand of a continuous rigid frame bridge with high …
Lightweight Replacement Technology For Existing Soft Subgrade Based On Over‑Consolidated State,
2024
School of Marine Engineering Equipment ， Zhejiang Ocean University ， Zhoushan ， Zhejiang 316022 ， China ;School of Naval Architecture and Maritime ， Zhejiang Ocean University ， Zhoushan ， Zhejiang 316022 ， China
Lightweight Replacement Technology For Existing Soft Subgrade Based On Over‑Consolidated State, Huang Baotao, Zhang Mudan, Huang Xiangshuo, Fang Mingshan, Feng Jianxue, Huang Lizhen
Journal of China & Foreign Highway
In order to solve the differential settlement of soft subgrade in coastal areas，based on the elastic deformation theory of overconsolidation stress ratio，the calculation and analysis of artificial overconsolidation stress ratio and the new technology of lightweight replacement were carried out to reduce the additional stress of vehicle load and structure weigh.The results show that the replacement thickness of the lightweight material with suitable density can make the additional stress at the bottom of the subgrade less than the deadweight stress of the original soft soil，and the additional stress is less than the initial flow stress of the soft soil.The resulting …
Analysis Of Stress And Drainage Characteristics Of Water Film Between Tire And Road Surface And Influence Of Groove Parameters,
2024
Shandong Provincial Communications Planning and Design Institute Group Co .， Ltd.， Jinan ， Shandong 250101 ， China ;College of Civil and Transportation Engineering ， Hohai University ， Nanjing ， Jiangsu 210098 ， China
Analysis Of Stress And Drainage Characteristics Of Water Film Between Tire And Road Surface And Influence Of Groove Parameters, Sun Zhenhao, Chen Jun
Journal of China & Foreign Highway
In order to study the stress characterist ics of water film on cement concrete road surface under the action of the tire and the influence of grooves，the finite element model of tire-water film-road surface was constructed using SolidWorks and Ansys Workbench.Based on computational fluid dynamics （CFD ） control equation and fluid-structure coupling theory，the flow law of water film on road surface under the action of the tire and the influence of water film thickness，driving speed，groove width，groove spacing，and groove direction on the hydrodynamic lift of tire were analyzed.The results show that the hydrodynamic lift of the tire increases with the increasing …
Influence Of Rap Content On Mechanical Properties And Pavement Performance Of Warm Recycled Asphalt Mixture,
2024
School of Transportation Engineering ， Shandong Jianzhu University ， Jinan ， Shandong 250101 ， China
Influence Of Rap Content On Mechanical Properties And Pavement Performance Of Warm Recycled Asphalt Mixture, Ren Ruibo, Yin Liyang, Xu Qiang, Zhao Pinhui, Ma Shidong
Journal of China & Foreign Highway
Warm recycling technology is an effective new technology for recycling recycled asphalt pavement （RAP ）.In order to improve the pavement performance of warm recycled asphalt and effectively enhance the recycling rate of RAP，the influence of RAP content on the performance of warm recycled asphalt mixture was investigated through mechanical properties and pavement performance analysis，and the correlation between dynamic stability and mechanical parameters of creep tests under repeated loading was discussed.The results show that with the increase in RAP content，the high-temperature stability，shear resistance，and elastic deformation resistance of warm recycled asphalt mixture are improved，but the low-temperature crack resistance and water stability are …
Expressway Traffic Flow Prediction Based On Data From Multiple Related Toll Stations,
2024
School of Transportation ， Fujian University of Technology ， Fuzhou ， Fujian 350118 ， China
Expressway Traffic Flow Prediction Based On Data From Multiple Related Toll Stations, Zhang Yang, Yao Fangyu, Yang Shumin
Journal of China & Foreign Highway
The strong inter-economic connection makes a spatial correlation between traffic data from multiple related toll stations between urban cluster regions，and an accurate description of this connection can improve the accuracy of expressway traffic flow prediction.However，due to many uncertainties，the correlation is difficult to be captured and quantified.To solve this problem，an ATGCN-ResGRU deep learning-based expressway traffic flow prediction method was proposed.By combining attention mechanisms，three graph convolutional networks （GCN ） topological networks with high，medium，and low attention levels were constructed，and spatial learning data was obtained according to the weighted attention level of each network.The connection of multiple related toll stations was quantified and graded.At …
Carbon Emission Calculation And Scheme Selection For Roadbed Drainage Ditches By Mechanized Construction,
2024
The Fourth Engineering Company of China Railway Seventh Group Co .， Ltd.， Wuhan ， Hubei 430074 ， China
Carbon Emission Calculation And Scheme Selection For Roadbed Drainage Ditches By Mechanized Construction, Xing Hao, Wu Jiarun, Li Han, Lin Yuliang, Guo Dongdong
Journal of China & Foreign Highway
Aligned with the peak carbon and neutrality goals，the mechanized construction of roadbed drainage ditches should consider not only construction efficiency and economic factors but also carbon emissions.This study，centered on the Meng-LYU highway，devised approaches to calculate roadbed drainage ditches' carbon emissions and investment costs across three stages：building material production，transportation，and construction.By introducing the concept of carbon trading to align carbon emissions and investment costs，a comprehensive comparison was conducted between the conventional supporting formwork method and the hydraulically powered sliding formwork method regarding equivalent carbon emissions.An orthogonal experiment was conducted involving the upper length of the roadbed drainage ditch，pouring thickness，haul distance，and construction length …
Study On Treatment Method Of Expansive Soil Embankment In Expressway Reconstruction And Extension,
2024
Anhui Transportation Holding Group Co .， Ltd.， Hefei ， Anhui 230088 ， China
Study On Treatment Method Of Expansive Soil Embankment In Expressway Reconstruction And Extension, Wang Yuwei, Hu Yanli, Zhang Rui
Journal of China & Foreign Highway
In order to fully utilize expansive soil as filler in highway reconstruction and expansion projects，this paper draws on the successful experience of using expansive soil directly in road construction.It proposes an embankment treatment scheme that involves the use of geogrid-reinforced expansive soil with edge wrapping，based on the reconstruction and expansion project of the Hefei to Dagudian section of the G 40 Shanghai-Shaanxi Expressway.Through laboratory tests，the road performance and swelling characteristics of the expansive soil filler were investigated to determine the applicable scope and compaction control indices of the filler.Then，the feasibility of the embankment treatment scheme was demonstrated through the prediction …
Prediction Method Of Surrounding Rock Deformation Of Highway Tunnels Based On Bayes‑Lstm,
2024
CCCC First Highway Consultants Co .， Ltd.， Xi'an ， Shaanxi 710076 ， China
Prediction Method Of Surrounding Rock Deformation Of Highway Tunnels Based On Bayes‑Lstm, Liu Zhi, Li Xinyu, Li Zhen, Kong Xianguang, Chang Jiantao
Journal of China & Foreign Highway
In the process of highway tunnel construction，the stability of surrounding rock has a great impact on tunnel construction.Therefore，the monitoring measurement and accurate prediction of surrounding rock deformation of highway tunnels are the keys to ensuring the safety of tunnel construction.In view of the low prediction accuracy and poor generalization ability of tunnel surrounding rock deformation，this paper proposed a Bayesian （Bayes ）-based method to optimize the long-term and short-term memory （LSTM ） network.The method first preprocessed the original monitoring data of crown settlement and peripheral convergence，then constructed the initial LSTM model of crown settlement and peripheral convergence of highway tunnels，and used …
Comparative Analysis Of Test Results Of Different Nano‑Clay Improved Loess,
2024
School of Highway ， Chang'an University ， Xi'an ， Shaanxi 710064 ， China
Comparative Analysis Of Test Results Of Different Nano‑Clay Improved Loess, Zhao Danni, Cao Baohua, Xu Jiangbo, Nan Yalin, Chen Nengyuan, Zhang Peng, Wang Heping
Journal of China & Foreign Highway
The orthogonal design t est was used to quantitatively analyze the influencing factors and influence degree of compressive strength，shear strength index，and permeability coefficient of improved loess，and the optimal content of improved loess was obtained.In addition，the improvement mechanism of nano-clay materials on loess was explored by scanning electron microscopy.The results show that：① The factors affecting the compressive strength of improved loess are the content of nano-clay，water content，and curing age，and the factors affecting cohesion，internal friction angle，and permeability coefficient are the content，dry density，and confining pressure.② Under different influencing factors，nano-montmorillonite can effectively improve the compressive strength of loess than attapulgite.③ When the material content …
Technical Essentials Of Road Geometric Design In Serbia,
2024
China Railway Design Corporation ， Tianjin 300142 ， China
Technical Essentials Of Road Geometric Design In Serbia, Xu Da, Yang Xueyong, Yuan Yingshuang, Chen Dongsheng
Journal of China & Foreign Highway
With the continuous advancement of China's Belt and Road Initiative，more and more Chinese enterprises are participating in the construction of engineering projects in Central and Eastern Europe，which brings some challenges for designers to master and use local codes for engineering design and consultation.According to the concrete practice of road reconstruction design of Hungary-Serbia Railway （Serbia section ），the application of horizontal and vertical indexes in road geometric design in Serbian was summarized.It is found that road design in Serbian has perfect design standards and systems.The Serbian code and the Chinese code are relatively close in terms of road geometric design standards，and …
Effect Evaluation Method Of Foamed Asphalt Based On Digital Image Processing Technology,
2024
Shanxi Transportation Research Institute Group Co .， Ltd.， Taiyuan ， Shanxi 030000 ， China ;Shanxi Transportation Technology Research & Development Co .， Ltd.， Taiyuan ， Shanxi 030000 ， China
Effect Evaluation Method Of Foamed Asphalt Based On Digital Image Processing Technology, Chang Xiaoyu
Journal of China & Foreign Highway
In view of the shortage of deter mining the optimal foaming parameters of foamed asphalt only by experience，this paper adopted digital image processing technology to collect images of the mixture of foamed asphalt and milled material RAI obtained under different foaming conditions and carried out grayscale image conversion，morphological processing，binary image conversion，and image segmentation，so as to calculate the asphalt wrapping rate in different areas.With the uniform dispersion of asphalt in the mixture as the indicator，the foaming effect of foamed asphalt was evaluated，and the optimal foaming parameters were determined.The results show that the digital image processing technology can quickly and effectively evaluate …
Research On Construction Risk Of Desert Highway Subgrade Engineering Based On Sem,
2024
School of Traffic and Transportation Engineering ，Changsha University of Science ＆Technology ，Changsha ， Hunan 410114 ，China
Research On Construction Risk Of Desert Highway Subgrade Engineering Based On Sem, Wang Shouxu, Han Lingyun
Journal of China & Foreign Highway
Highway construction in desert areas is of great significance to improving the nodes of transportation networks and developing the economy of remote areas.In order to effectively explore the construction risks of desert highway subgrade engineering，the five aspects of personnel risk，technical risk，material risk，mechanical risk，and environmental risk were analyzed，and 23 indicators affecting the construction risk of desert highway subgrade engineering were screened out by literature research method.Based on the effective data collected by questionnaire survey，a structural equation model （SEM ） of the construction risk of desert highway subgrade engineering was constructed，and the key influencing factors of the construction risk were analyzed.The results …
