Digital Commons Network^™

Internal Force Optimization In Com Pleted Stage And Construction Alignment Control Of Super Long-Span Extradosed Cable-Stayed Bridge, Ba Wenpeng

Journal of China & Foreign Highway

This paper is based on a super long-span extradosed cable-stayed bridge with a main span of 400 m.In view of the technical challenges of high negative bending moment at the quarter point of the bridge and large deformation during the cantilever assembly process in the non-cable area,a systematic solution was proposed in combination with the entire construction process.This paper proposed three schemes:permanent cable over-tensioning,temporary cable setting,and large segment closure.The bending moment ratio (λM) and structural deformation were used as quantitative indicators,and a finite element model was established to compare the three schemes.The results show that all three schemes can improve …

Comparative Study On Differences In Asphalt Pavement Design Between China And Southern Africa, Wang Qing, Lin Yangyang, Yan Hongxiang, Zhao Bin, Xia Moxuan, Li Ning, Si Wei

Journal of China & Foreign Highway

To facilitate the successful implementation of projects in the Southern Africa region and promote the application and internationalization of China ’s standards,this study compared the asphalt pavement design systems,construction materials,design parameters,and structural design methods of both regions based on the main asphalt pavement design specifications currently in use in China and Southern Africa.The results show that among Southern African countries,South Africa has a comprehensive and widely applied standard system,while other Southern African countries adopt more varied and less theoretical standards.In contrast,China ’s standard system is complete and highly practical.Due to differences in regional climates,the selection principles and mechanical requirements for …

Discontinuous Deforma Tion Analysis Of Progressive Toppling Of Rock Slopes With Fractured Slab Structure, Yuan Sifan, Li Tonglu, Haider Mumtaz, Zhang Changliang, Li Ping

Journal of China & Foreign Highway

Progressive toppling of rock sl opes with fractured slab structures is quite common in the slopes of hydropower and highway engineering,posing a potential safety risk during both construction and operational phases.The field investigation found that progressive toppling mostly occurs on slopes with concentrated tectonic stress,intense river incision,and high steepness.Typically,these slopes are composed of hard,thinly-layered,and overthrusted rock mass with a fractured slab structure.From a macroscopic point of view,progressive toppling failure is neither a collapse nor a slide but a form of discontinuous deformation.The traditional limit equilibrium method for slope stability analysis is not suitable for evaluating such slopes.In this paper,by taking …

Prediction For Humidity Adjustment Factor And Dry-Wet Cycle Reduction Factor Of Resilient Modulus Of Subgrade Soil Based On Ann, Wang Xufeng, Fu Wei, Peng Junhui, Hu Jiankun, Zhang Junhui, Li Zhiguang

Journal of China & Foreign Highway

Existing methods for determining the humidity adjustment factor and dry-wet cycle reduction factor of the resilient modulus of subgrade soil are mostly based on laboratory tests that consume a large amount of manpower and time,and the prediction accuracy is limited due to the constraints of specification value ranges.In order to achieve fast and accurate prediction of these two factors,the effects of stress state,moisture content,and the number of dry-wet cycles on the resilient modulus of subgrade soil were investigated through laboratory dynamic triaxial tests.Based on existing literature,physical parameters,state parameters,and stress parameters of subgrade soil were selected,and an artificial neural network prediction …

Semi-Flexible Pavement Structure Analysis Based On Double Modulus Theory, Pan Qinxue, Zhou Shurui, Hu Jia, Zhang Long, Song Xiaojin, Liu Hongfu

Journal of China & Foreign Highway

Semi-flexible pavement materials have significant differences in tension and compression.If the mechanical response analysis of pavement structures is conducted by using the traditional linear elastic theory with a single modulus,there will be a considerable deviation from actual situations.To analyze and optimize semi-flexible pavement structures,this paper compared the changes in key mechanical responses of pavement structures under six different semi-flexible layer positions and thickness combinations based on the double modulus theory.The results show that there is a significant difference in the calculation results of key mechanical responses of the pavement based on the double modulus theory and the single modulus theory,with …

Structural System Reliability Analysis Method For Cable-Supported Bridges Based On Deep Belief Networks, Chen Zhenyu, Xie Bo, Lu Naiwei

Journal of China & Foreign Highway

Aiming at the high-precision reconstruction of structural function functions caused by the strong nonlinearity of cable load-bearing bridge structures,this study presented a structural system reliability analysis method based on a deep belief network (DBN ).A long-span suspension bridge was used as the engineering background to identify the dominant fault path of the structural system and analyze the law of structural fault path transfer caused by the deterioration of the suspender strength.Numerical analysis results show that DBN can capture the nonlinear mechanical behavior of the finite element model of the suspension bridge,thereby making the implicit statically indeterminate functional function explicit and …

Hypertensive Disorders Of Pregnancy And Perinatal Outcomes: Two Prospective Cohort Studies Of Nulliparous Women In India And Tanzania, Andrea B. Pembe, Pratibha Dwarkanath, Amani Kikula, John Michael Raj, Nandita Perumal Phd, Heavenlight A. Paulo, Rajalakshmi M, Christopher P. Duggan, Honorati M. Masanja, Nandini Chopra, Mary M. Sando, Tinku Thomas, Cara A. Yelverton, Alfa Muhihi, Anura V. Kurpad, Wafaie E. Fawzi, Blair J. Wylie, Christopher R. Sudfeld

Faculty Publications

Introduction Hypertensive disorders of pregnancy (HDP) have been linked with increased risk for maternal and offspring complications in high-income settings. However, in resource-limited settings, studies with robust measurement of HDP, including severity and timing, and perinatal outcomes are limited.

Methods We analysed data from two prospective cohorts of nulliparous women in India (n=10 570 pregnancies) and Tanzania (n=10 299 pregnancies) who were enrolled in calcium supplementation trials and had blood pressure and proteinuria assessments throughout pregnancy and at the time of labour and delivery. Generalised estimating equations were used to assess the relationship between HDP severity categories (gestational hypertension, preeclampsia …

Experimental Study On Engineering Performance Of Post-Planted Precast Concrete Pile With Prebored Grouting, Zhao Yu, Wang Wei, Jiang Lei, Song Zhenya, Zhang Hao

Journal of China & Foreign Highway

The traditional piling methods of precast concrete (PC) piles are difficult to pass through the hard soil layers and tend to induce severe soil squeezing effects.To address this issue,the technology of a post-planted PC pile with prebored grouting was analyzed.Based on the project of the Hefei‒ Zongyang section of G3W Dezhou ‒ Shangrao Expressway,the bearing characteristics of post-planted PC piles were researched by the load tests of five piles in two different field test sections.The results show that the bearing capacity of the PC piles can be effectively improved by setting the cement mortar coating layer around the PC piles.The …

Research On Evaluation Index Of Low-Temperature Semi-Circular Bending Test Of Asphalt Mixtures, Lyu Songtao, Chen Qi, Lu Weiwei, Zhao Pei, Wang Jinping

Journal of China & Foreign Highway

This article aims to investigate the low-temperature crack resistance performance of asphalt mixtures under different aging conditions and loading rates and select appropriate indicators to accurately characterize and quantify their performance.Based on the semi-circular bending test,the influence of different aging degrees (unaged,short-term aged,long-term aged for three days,and long-term aged for five days ) and loading rates (50 mm/min,5 mm/min,0.5 mm/min,and 0.1 mm/min ) on the low-temperature performance of asphalt mixtures was investigated.The evaluation effect and applicable range of five crack resistance performance indicators,namely fracture energy (Gf),stress intensity factor (KIC),flexibility index (IFI),crack resistance index (ICRI),and balanced cracking index (IBCI),were studied through …

Research On Pavement Crack Segmentation Based On Swin-U, Wang Hua, Wang Liangcai, Xiong Feng, Hu Jing

Journal of China & Foreign Highway

To address the issues of overfitting,low computational speed,and insufficient target information extraction in pavement crack segmentation tasks,this study proposed a Swin-U network model based on the U-Net architecture.The model adopted the Swin-Transformer as the feature extraction module to enhance the model ’s fitting capability and enable more accurate crack feature extraction,thereby enhancing segmentation accuracy.Additionally,a stable loss function,Focal Loss,was introduced to improve the accuracy of target segmentation.Experiment results on a proprietary pavement crack dataset show that the Swin-U network model achieves pixel-level segmentation of crack images and significantly outperforms the traditional U-Net.On the test set,it improves the intersection over union and …

Long-Term Water P Ermeability Performance Of Asphalt Mixtures Under Wide-Scope Void Ratio, Chen Sanxi, Guan Hongxin, Yao Ming, Mo Zhiwei, Jiang Wangheng

Journal of China & Foreign Highway

In order to compare the water pe rmeability performance of asphalt mixtures with different void ratios after scouring and clogging,self-developed equipment was adopted to conduct vertical water permeability tests,dynamic water scouring-based water permeability tests,water pressure tests,and simulated clogging tests on semi-open-graded DK- 13 mixtures with void ratios of 9%,11%,and 13%,as well as open-graded PA- 13 mixtures with void ratios of 15%,17%,and 19%.The experimental results show that:① The water permeability performance of the asphalt mixture becomes better as the void ratio increases.The water permeability coefficient changes relatively small after the void ratio of the asphalt mixture reaches 15%,which is attributed to …

Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui

Journal of China & Foreign Highway

As a new structure with sloping arch ribs and curved main beams,a skewed arch and curved beam bridge markedly differs from the conventional bridge in construction monitoring technology due to its complex structure and prominent spatial effect.To investigate the key technology in construction monitoring,this study took a long-span skewed arch and curved beam bridge as the engineering background and discussed construction process simulation analysis,field monitoring,and parameter identification and adjustment of the bridge.The results show that the plate-shell unit model has higher calculation accuracy and can comprehensively show the stresses in all directions of the bridge compared with the beam element …

Study On Aerodynamic Optimization Of Π-Shaped Cable-Stayed Bridge With Vortex-Induced Vibration In Mountainous Areas, Zeng Min, Liu Hanyun, Mao Na, Chen Baixiang, Han Yan, Li Chunguang

Journal of China & Foreign Highway

Given vortex-induced vibrations of bridges caused by high wind attack angles in mountainous canyons,this study investigated the vortex-induced dynamic characteristics of a Π-shaped steel-concrete composite beam cable-stayed bridge in a mountainous canyon under high wind attack angles based on wind tunnel tests and examined aerodynamic measures for vortex suppression.Firstly,a finite element model of the bridge was established,and the dynamic characteristics of the bridge in both the completed and construction states were analyzed.Subsequently,a 1∶50 scale detailed segment model was designed based on similarity theory to analyze the vortex-induced vibration performance of the original main beam under conventional wind attack angles of …

Wind Tunnel Experiment On Wind-In Duced Vibration Performance Of Arch-Shaped Inclined Steel Bridge Tower In Construction Free-Standing State Using Ae Roelastic Model, Xu Peijun, Deng Fei Yun, Chen Shixuan, Zhang Jiren

Journal of China & Foreign Highway

This paper presented a wind tunnel experimental study on the wind-induced response characteristics of a rectangular-sectioned arch-shaped inclined steel bridge tower during the construction free-standing stage.A 1:50 scaled aeroelastic model was employed to conduct experiments at different wind yaw angles β (0°‒180°).The experimental results indicate:① under the uniform flow field,the tower in its free-standing state does not experience galloping when the bridge ’s wind speed reaches 60 m/s;② under the uniform flow field,the tower exhibits bending vortex-induced vibrations (VIVs ) along the bridge direction or transverse to the bridge direction.However,the amplitudes of the tower top displacements associated with these VIVs …

Numerical Simulation Study On Scour Erosion Of Bridge Pile Foundations In Service, Wang Shang, Mi Jiangchuan, Chen Mingtao, Song Dan, Zhang Qiao, Zhang Yong, Wang Weixiao

Journal of China & Foreign Highway

Bridge pile foundations in servic e are subjected to long-term scour erosion caused by sediment-laden water flow,leading to a gradual expansion of the eroded and worn areas.This in turn results in varying degrees of damage to the pile foundation structure and reduces the durability and safety of the bridge.In order to study the impact of scour erosion on bridge pile foundations,this study took the Hanjiang No.1 Bridge in Ankang City as the research object.The ANSYS FLUENT software was used to conduct three-dimensional numerical simulations of the pile foundation and analyze the distribution characteristics and patterns of scour erosion under different …

Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming

Journal of China & Foreign Highway

In order to determine reasonable grouting parameters,control surface settlement,and reduce the risk of excessive surface settlement caused by irrational synchronous grouting parameters,this study studied the shield tunnel project between maglev T 2 station and maglev T 3 station.A numerical simulation method was adopted to study the influence of grouting pressure,grouting volume,and the elastic modulus of slurry on surface deformation.The results show that the tunnel synchronous grouting has a significant effect on surface settlement control.A greater grouting pressure,equivalent grouting layer thickness,and elastic modulus of slurry mean a smaller surface settlement.As the three parameters increase,the variation range of surface settlement decreases and …

Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan

Journal of China & Foreign Highway

In the field of fault-tolerant control for intelligent vehicle path tracking,the existing methods based on model predictive control (MPC ) have limitations.They often assume that the vehicle model parameters are fixed and ignore the impact of dynamic changes in model parameters,which are caused by factors such as vehicle load changes and external environmental interference,on the path tracking accuracy.When the steering system fails,the front wheel steering angle commands calculated by MPC cannot be directly executed and need to be converted into yaw moment control.Although the existing sliding mode yaw moment control methods have strong robustness,the chattering problem affects the stability and …

Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan

Journal of China & Foreign Highway

By analyzing the application points and the current situation of digital delivery in each stage of highway engineering construction,this study found that the lack of parameter management and definition in the modification and refinement process of building information modeling (BIM ) source files at each stage led to difficulties in the splitting and refinement of BIM at each stage and even the need for reconstruction.To this end,a method for strengthening the overall planning of the whole life cycle was proposed.By clarifying the demand for model parameters according to the application points of each stage,a mechanism for parameter reservation and classification …

Reconstruction Plan Of Small-Spacing Interchange Connection Sections On Expressway : A Case Study Of Xinlong‒Gangkou Interchange On Zhongshan‒Jiangmen Expressway, Jie Qiang, Fu Xinsha

Journal of China & Foreign Highway

The plan design for the small-spacing interchange connection on the expressway directly affects operational efficiency and driving safety.To achieve the conversion of traffic flow between different expressways,this study explored the reconstruction plan of the connection section under the condition that the interchange spacing did not meet the Design Specification for Highway Alignment (JTG D20‒2017 ) and investigated two connection schemes,including auxiliary lane and collector-distributor lane by taking the Xinlong –Gangkou interchange of the Zhongshan‒Jiangmen Expressway reconstruction and expansion project as an example.The results show that the auxiliary lane is recommended in consideration of the long-term service level,speed coordination,operational efficiency,and engineering …

Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader

Journal of China & Foreign Highway

The Champlain Bridge,an iconic gateway spanning the St.Lawrence River in Montreal,showcases not only the excellence of engineering but also becomes an integral part of the city ’s landscape.With a main span of 240 m,the bridge employs a unique single-pylon harp-shaped double-plane cable-stayed structure.The upper pylon is inspired by a tuning fork in its lateral design,while the upper crossbeam artfully mimics the shape of a bow tie,endowing the bridge with a visual beauty that harmoniously blends elegance and strength.The bridge deck,with a total width of 60 m,was the widest double-plane cable-stayed bridge in the world when it was completed.The typical spans …

Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou

Journal of China & Foreign Highway

To lift the longitudinal section of existing bridges in highway reconstruction and expansion projects due to insufficient under-bridge clearance,this study took the reconstruction of a 32.5 m T-beam bridge in the reconstruction and expansion project of the Guangzhou‒Shenzhen Expressway as the research object.By using a carbon emission factor method,carbon emissions of three reconstruction schemes,including broken-column jacking,conversion of bearing pads into bridge piers,and demolition and reconstruction,were calculated under different lifting heights,and the corresponding construction and installation costs were compared.The results show that when the longitudinal section of the bridge is lifted to a certain height,the economic benefits of the broken-column jacking …

Research On Rc-Uhpc Composite Slab Frame Culvert Technology In Wave-Affected Areas, Qiu Junfeng

Journal of China & Foreign Highway

To address the problems in the construction of offshore bridges and culverts such as the structures susceptible to waves,limited layout,and high cost of soft foundation treatment,this paper proposed a new technical solution for reinforced concrete and ultra-high performance concrete (RC-UHPC ) composite slab frame culverts.With supporting engineering,the ordinary box culvert was selected as a comparison scheme for technical and economic analysis,and the design points and construction procedures of new structures were introduced.Based on the calculation results of the overall bearing force,the bearing performance of the top slab under different load conditions was analyzed,along with an investigation of the secondary internal …

Inverse Analysis Of Thermal Parameters Of Concrete Box Girder Based On De-Bp Neural Network, Yao Yong, Yan Yu, Sun Bo Wen, Wang Yuesong, Jiang Tianyong

Journal of China & Foreign Highway

In view of temperature cracks in concrete box girders easily occurring during construction,an inverse analysis method based on uniform design theory and differential evolution back propagation (DE-BP ) neural network was proposed to accurately obtain the thermal parameters of concrete box girders and ensure the reliability of temperature analysis of concrete box girders.This method established the nonlinear relationship between the temperature peak of characteristic points and the thermal parameters through the DE-BP neural network.By using the uniform design method and the Abaqus finite element numerical model,130 sets of sample data were generated.Based on the ratio of 12∶1 for training samples …

Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan

Journal of China & Foreign Highway

This study aims to address poor adaptability and timeliness in the design of smooth blasting hole parameters in t he past.With the drilling and blasting method-based construction of large cross-section tunnels in Botanggou and Tielugou along the Zunhua‒Qinhuangdao Expressway as the research background and Ⅲ and Ⅳ grade surrounding rocks of porphyritic granite as the research object,statistical regression analysis and theoretical derivation were conducted on the measured data during on-site drilling according to the rock solidity coefficient.Based on this,a simple parameter design method for a smooth blasting layer based on the drilling speed index of an air leg anchor rod …

Distribution Characteristics Of Internal Distress And Maintenance Decision-Making For Asphalt Pavement Based On Three-Dimensional Ground-Penetrating Radar, Li Xiaohua, Song Liang, Ye Wei, Xie Xiaodong, Yang Jiangang, Gao Jie

Journal of China & Foreign Highway

The distribution characteristics of internal distress in pavement structures and the corresponding maintenance decisions are crucial for improving road performance and extending service life.Based on three-dimensional ground-penetrating radar (3D GPR ) technology,this study investigated the internal distress of a 12-kilometer section of both driving and overtaking lanes of an expressway in Hubei Province.High-resolution images of internal pavement distress were obtained,and milling maintenance decisions were optimized by employing these images and a modular decision-making model.Through an efficient and non-destructive technique,the distribution characteristics of internal pavement distress were analyzed,and potential distress types were identified,providing a scientific basis for maintenance decision-making.Data analysis revealed …

Association Between Dietary Inflammatory And Antioxidant Potential And Systemic Inflammatory And Oxidative Status With The Risk And Severity Of Coronary Artery Disease, Zahara Namkhah, Elham Alipoor, Manhnaz Salmani, Negar Ebrahimi, Monireh Ahmadpanahi, Ali Vasheghani-Farahani, Mehdi Yaseri, Michael David Wirth, Longgang Zhao, James Hébert Scd, Javad Hosseinzadeh-Attar

Faculty Publications

Background and aims

Unhealthy diets have pro-inflammatory properties that have been shown to contribute to coronary artery disease (CAD). The dietary inflammatory index (DII®) and the dietary antioxidant quality score (DAQS) quantify the anti-/pro-inflammatory and antioxidant potential of a diet. This study aims to investigate the association between the energy-adjusted DII (E-DIITM), DAQS, oxidant/anti-oxidant biomarkers, and CAD risk and severity.

Methods and results

This cross-sectional study investigated 158 participants for the presence and severity of CAD based on coronary angiography. E-DII and DAQS scores, malondialdehyde (MDA), total oxidant status (TOS), glutathione peroxidase (GPX) activity, total antioxidant capacity (TAC) and conventional …

How’S It Growing? Tools For Observing Snow And Sea Ice In A Changing Arctic Ocean, Ian Alexander Raphael

Dartmouth College Ph.D Dissertations

September Arctic sea ice extent has diminished by roughly 50% in the 45 years since satellite observations began. The Arctic Ocean may experience ice-free summers within the next decade, with implications for habitat, resource extraction, geopolitics, and local and global climate change. To predict how Arctic sea ice will change in the future, we need to understand its behavior in the present. In situ sea ice mass balance measurements (snow accumulation, ice growth, snow and ice surface melt, and bottom melt) are essential for studying the processes driving rapid changes in the ice pack, and for validating remote sensing measurements …

Conceptualizing The Explanatory Fully Longitudinal Mixed Methods Case Study Design: A Demonstration With An Arithmetic Education Trial With Kindergarten Children, Menglong Cong

Electronic Theses and Dissertations

In employing longitudinal mixed methods designs, researchers have commonly used the fully longitudinal mixed methods design. This has occurred mostly in the health sciences but less in education. The current investigation proposes a novel longitudinal mixed methods research design, explanatory fully longitudinal mixed methods case study design. It demonstrates its potential for addressing research inquiries in educational research using the arithmetic learning trajectories datasets. This study is presented in three components. The first is a quantitative phase, selecting an exploratory case from a previous arithmetic learning trajectories study (Clements et al., 2021) for qualitative analyses based on maximizing the …

Some Results In Thermodynamic Formalism, C. Evans Hedges

Electronic Theses and Dissertations

This dissertation investigates several key questions at the intersection of dynamical systems, computability theory, and thermodynamic formalism. In the symbolic setting, we establish novel results regarding the statistical properties of equilibrium states, deriving bounds on probabilities of configurations and relating these bounds to the Gibbs property through the homoclinic relation. Additionally, we examine the computability of thermodynamic quantities such as pressure, ground state energy, and residual entropy. We show that topological pressure is computable from above for general subshifts and computable for strongly irreducible shifts, with similar results extending to ground state energy and residual entropy.

Extending beyond subshifts, we …

A Study On Fuzzy Time-Series And Its Applications To Stock Price Forecasting, Takeshi Stormer

University Honors Theses

Fuzzy mathematics looks to incorporate the vagueness that exists within the real world, specifically regarding imprecise classes, or non-numerical information expressed as "linguistic" variables. Since most traditional mathematical theories do not have the ability to be applied with the exactness that is otherwise seen in mathematics. As such, there had been many applications of fuzzy mathematics throughout many different fields of mathematics, including that of forecasting. By exploring the fundamentals of fuzzy mathematics, including fuzzy sets, operations of fuzzy sets, the surface level introduction to fuzzy logic, fuzzy relations, operations of fuzzy relations, and fuzzy time-series, this work looks to …