Civil and Environmental Engineering Commons^™

Design And Stress Analysis Of Baqiutian Jointless Arch Br Idge In Yunnan, Chen Baochun, Sun Tongqing, Huang Qingwei, Han Yu, Shi Zhi

Journal of China & Foreign Highway

The bridge without expansion joints, with the expansion device removed, can completely solve the maintenance problem of the expansion device and is sustainable. Its application is mainly in beam bridges and relatively few in arch bridges. In this paper, the Baqiutian Bridge in Yunnan Province was taken as an example, which is an upper bearing arch bridge. The arch path structure is directly connected with the two approach spans to form a continuous structure and extends to the guide plate (approach slab) behind the platform, thus eliminating the expansion joints of the whole bridge floor and making it an arch …

Analysis And Optimal Adjustment Of Manufacturing Errors Of Main Girder Of Long ⁃Span Steel Box Cable ⁃Stayed Bridge, Tu Guangya, Zhou Zhizhe

Journal of China & Foreign Highway

In order to study the influence of the random manufacturing error of the main girder permitted by the research specification on the alignment of the finished long-span steel box cable-stayed bridge, guided by the adaptive stress-free configuration construction control theory, the Shishou Yangtze River Highway Bridge, a long-span twin-tower cable-stayed bridge, was studied. The influence and propagation characteristics of the random error effect of the main girder members on the main structure of the cable-stayed bridge were analyzed. The adverse effects of random manufacturing errors of the main girder on the structure of the cable-stayed bridge were studied. The results …

Design Of Super Large Cantilever Wing ⁃Box Girder Bridge, Zhong Hao

Journal of China & Foreign Highway

In recent years, with the rapid development of urban bridge construction, the bridge inevitably needs to cross the existing railway and road in the construction project. This kind of bridge has the characteristics of a large span and limited pier space. At the same time, in order to meet the increasing traffic demand, the transverse width of the bridge is increasing, so the application of large cantilever wing-box girder structures is becoming more and more extensive. Based on the overspan railway bridge project of the northern section of the Wuhan Fourth Ring Line (Wuhu–Wujiashan), this paper introduced the design difficulties …

Study On Reasonable Seismic System Of Long ⁃Span Concrete Beam Bridge In Strong Earthquake Areas, Yu Deen, Han Shanjian, Sun Pingkuan

Journal of China & Foreign Highway

In this paper, a three-dimensional finite element dynamic model of the Longtang Nandujiang Bridge in Hainan Province was established. Firstly, the selection of ground motion input and the establishment of the finite element model were introduced. Secondly, the influence of different design parameters (support radius) of the friction pendulum bearing on the seismic response of the bridge was discussed, and the optimal bearing parameters suitable for the bridge were obtained. Finally, the seismic responses of the bridge under three different constraint structures, namely conventional constraint system, seismic isolation system of friction pendulum bearing, and rigid frame bridge system, were compared. …

Calculation Of Arch Rib Installation Alignment Of Large Span Cable Hoisting Arch Bridge, Xiong Shaohui, Guo Xin, You Zuoqiao

Journal of China & Foreign Highway

Cable hoisting method is the most important construction method for long-span arch bridges. In the process of arch rib lifting, the partial consolidation of the joint caused by temporary bolt connection, the deflection of the tower caused by the temporary construction load of the main cable, and the free expansion of the anchor cable and the buckle cable caused by temperature change will have a great influence on the installation alignment of the arch rib. In this paper, a two-element model method considering stiffness loss was used to calculate the correction value of the arch rib installation alignment more accurately …

Analysis Of Installation Method And Error Control Of Steel Girder Of Steel ⁃Concrete Composite Girder Cable ⁃Stayed Bridge, Xiong Xianyong, Fu Yajun, Huang Gen

Journal of China & Foreign Highway

Compared with cable-stayed bridges with pure steel girders, the installation of a steel main girder of the steel⁃concrete composite girder cable⁃stayed bridge is more complicated, and the installation error control is more difficult. In this paper, the composite girder with a double box section was taken as the research object, and a finite element model was established to compare the installation methods of steel main girders. The best installation method was selected according to the principle of safety loading, and the causes of the installation errors of steel main girders were analyzed. The corresponding error control methods were proposed.

Cable⁃Stayed Bridge Of Cable Auxiliary Beam Arch Pylon ⁃Key Technologies Design Of Meishan Minjiang Bridge, Ma Zhendong, Lai Yaping, Chen Jiayong

Journal of China & Foreign Highway

The newly built Minjiang Bridge in Meishan City, Sichuan Province applies the concept of cable-assisted girder bridge. P4 steel arch tower combined with three-stage balanced double-plane cable and P3 and P5 auxiliary towers combined with thin cable of single cable plane were used to assist the load on the beam body, making the 2.5 m-high concrete main beam meet the requirements of the main span of 2 × 120 m. Through the analysis of the bearing force, the angle between the double-limb arch tower was 43.6°, and two pairs of cables were set in the auxiliary tower to achieve the …

Aesthetic Design Of Hechuan Qujiang Landscape Bridge, Zheng Guangqin, Chen Jiayong, Li Yue, Lai Yaping, Qiao Yunqiang

Journal of China & Foreign Highway

Hechuan Qujiang Landscape Bridge is located at the junction of Qujiang River and Jialing River. It is a 1 × 400 m simple supported single-cable surface ground anchor suspension bridge. The main girder is a steel box girder arranged with curved branches. One side is the highway system to meet the needs of motor vehicles across the river, and the other side is the greenway system to meet the needs of pedestrians and non-motor vehicles. In the design process, the aesthetic design of the bridge was fully studied from four aspects: environment aesthetics, structure aesthetics, function aesthetics, and form aesthetics. …

Study On Optimal Layout Of Cross ⁃Diaphragm In Oblique Small Box Girder, Mai Xinhao

Journal of China & Foreign Highway

In order to determine the optimal layout of the cross⁃diaphragms in the oblique small box girder, a prestressed concrete small box girder bridge with a 50 m span was taken as the research object, and its internal force under the load of the moving beam was numerically simulated and measured. First, the model was modified according to the measured stress data, and the maximum distance between the cross⁃diaphragms was determined by using the warping-limited normal stress. Then, the height and thickness of the middle cross⁃diaphragms were determined according to the deflection difference coefficient of the bridge span. Finally, according to …

Non⁃Gaussian Features Of Fluctuating Wind Pressures Under Combined Axle Condition, Chen Zhiqiang

Journal of China & Foreign Highway

In view of the non-Gaussian characteristics of wind pressure on the train surface of a typical high-speed railway train and bridge system, the Gaussian variable was expressed as a Hermite polynomial considering non-Gaussian variables by using Hermite series expansion method, and the probability density curve and peak factor of train surface were analyzed. The results show that the Davenport peak factor based on Gaussian distribution obviously underestimates the non-Gaussian peak factor, and its probability density curve deviates from the actual curve of the measuring point. The Hermite series peak factor method based on the modified method takes into account the …

Application Of 3d Reconstruction Model In Inspection Of Bridge Apparent Defects, Xu Guangli, Li Shaoyong, Tang Jun, Liu Shuqi, Zhou Yin

Journal of China & Foreign Highway

In view of problems such as low efficiency, poor accuracy, and imprecise three-dimensional (3D) location of defects in apparent defect inspection of bridges, this paper proposed a method for apparent defect inspection of bridges based on a 3D reconstruction model. By taking the indoor rectangular beam as the object, a three-dimensional bridge model was established, and its accuracy was verified. Then, based on the point cloud data derived from the model, a program was written in Python to realize the identification, measurement, and parameter derivation of apparent defects of bridges. Dade Bridge in Kunming, Yunnan Province was set as the …

Design And Construction Of Steel Caisson For Inclined Pilecap Of Beitstadsund Bridge In Norway, Yang Dingjun

Journal of China & Foreign Highway

At present, the underwater bridge foundation construction technology in China and abroad has been relatively mature, but the different geographical environments, hydrogeological conditions, the form of basic structure, and the available construction equipment lead to different construction schemes and technologies. The Beitstadsund Bridge in Norway is located near the Arctic Circle in central Norway and across the strait. In the design and construction of the deep-water steel cofferdam of the inclined steel pile cap for the bridge, the overall installation of the steel cofferdam was realized by setting the cofferdam support on the inclined steel pipe group, the overall positioning …

Study On Correction Method Of Cable Length Error In Construction Control Of Cable ⁃Stayed Bridges, Huang Gen, Chen Changsong

Journal of China & Foreign Highway

In order to effectively correct the stay cable length error during the construction of the cable-stayed bridge, this paper proposed a correction method with the exposure of the sockets as the error control index and analyzed the influence of the elastic modulus, temperature effect, and anchor point coordinates of the cable on the cable length error from the perspective of construction control. Then, error correction was achieved by adjusting the position of the manufacturing cable length and the nut at the anchor end. The results of application in Jiayu Yangtze River Highway Bridge show that this method can improve the …

Analysis Of Mechanical And Deformation Characteristics Of Karst Tunnel Structure And Research On Treatment Technology, Huang Haifeng, Chang Zhenchao, Luo Junhui, Zhou Xiang, Ceng Fuquan, Tian Fapai

Journal of China & Foreign Highway

Combined with the construction process of Nongmo Karst Tunnel on Du’an–Bama Expressway, this paper used Midas-GTS finite element calculation software to conduct numerical simulation research on the stability of surrounding rock and treatment structure of tunnel with karst caves on either side, analyzed the influence of tunnel excavation on the stress and deformation characteristics of surrounding rock and supporting structure, and probed into the treatment effect of biased wall and root pile on the treatment of karst tunnel. The results show that the surrounding rock at the bottom of the tunnel, the top of the composite foundation, and the top …

Effect Of Temperature And Light On Characteristics Of Asphalt Emissions, Zhu Xuwei, Tian Bo

Journal of China & Foreign Highway

In order to study the effects of temperature and light on the characteristics of asphalt emissions, atmospheric pressure chemical ionization–time-of-flight mass spectrometer (APCI‑TOF MS) and electron impact ionization mass spectrometry (EI‑MS) were used to quantitatively characterize the composition information of PG 62-22 asphalt emissions at different temperatures (40–200 °C). The effects of different temperatures and light on total emission factor, SOA conversion factor, intermediate volatile organic compound (IVOC)/semi-volatile organic compound (SVOC) volume fraction, and aromatics volume fraction of asphalt emissions were studied. The results show that the components of asphalt emissions change with temperature, and the components are complex and …

Study On Triaxial Mechanical Properties Of Glass Fiber Reinforced Cement Soil In Short Age, Wang Wei, Dai Mengdan, Yu Wenjie

Journal of China & Foreign Highway

In order to evaluate the improvement effect of fiber on the brittle damage of cement soil, a triaxial unconsolidated undrained (UU) test was carried out on glass fiber cement soil (GCS) with a curing age of 7 d and a mass fraction of glass fiber (GF) of 0, 2‰, 4‰, 6‰, and 8‰, respectively. The results show that: ① GCS retains the original strain softening characteristics of cement soil; ② For the same mass fraction of GF, the peak stress, peak strain, and residual strength of GCS samples increase gradually with the increase in confining pressure, but the brittleness index …

Study On Experimental Application Of Xinjiang Steel Slag In Cement Stabilized Base, Chen Wei, Yu Haiming, Li Qian, Huang Yong, Si Yi

Journal of China & Foreign Highway

Based on the experimental study of Xinjiang steel slag in cement-stabilized base, the physical and chemical characteristics of steel slag were analyzed, and the unconfined compressive strength, splitting strength, and dry shrinkage performance of cement-stabilized steel slag and gravel mixture with different cement dosages (4% and 5%) and steel slag contents (30%, 40%, and 60%) were analyzed. The test results show that steel slag can be used as a good engineering aggregate in a cement-stabilized base, and with the addition of steel slag, the unconfined compressive strength and splitting strength of steel slag and gravel mixture are increased to varying …

Mechanical Properties And Micro Analysis Of Cement Stabilized Steel Slag Macadam Base, Wan Tianbao

Journal of China & Foreign Highway

With steel slag as coarse aggregate, cement-stabilized steel slag macadam base material was designed and prepared by selecting three kinds of cement dosage and three kinds of steel slag content. The mechanical properties of cement-stabilized steel slag macadam base were studied through compaction and unconfined compressive strength tests, and XRD and SEM microscopic tests were carried out to analyze the mineral composition and microscopic morphology of steel slag and mixture and clarify the internal mechanism of hydration product formation and microstructure and strength formation. The results show that the maximum dry density and optimum moisture content of cement-stabilized steel slag …

Analysis Of Influence Of Moisture Content ⁃Temperature Dual Factor On Mechanical Properties Of Red Clay, Wang Jiangtao, Bao Temenbaiyila, Yang Weiguang, Zhou Qi, Fu Helin

Journal of China & Foreign Highway

Under the new climatic environment and engineering construction requirements, engineering problems involving red clay are becoming more and more prominent, and it is urgent to deeply grasp the mechanical and engineering properties of residual slope red clay. The typical red clay in Hunan Province was studied in this paper. Based on the unconsolidated undrained direct shear test, this paper studied the mechanical properties of residual slope red clay under the influence of moisture content and temperature, focusing on the most unfavorable conditions affecting the mechanical properties of red clay. The results show that: ① The shear strength of red clay …

Traffic Conflict Analysis Of Multila Neexpressway Based On Simulation, Ceng Yuekai, Zhou Tao, Chen Yazhen

Journal of China & Foreign Highway

In order to prevent traffic accidents on multi-lane expressways, the VISSIM traffic simulation model was established based on three types of multi-lane traffic conflicts: mixed passenger and cargo type, separated passenger and cargo type, and separated main and auxiliary type. SSAM software was used to obtain traffic conflict data, and the form, quantity, and location of the conflicts were analyzed. The results show that traffic conflicts are the most under the mixed passenger and cargo type, which are mainly distributed in the upper 100 m range of the innermost lane, outermost lane, and deceleration lane. The traffic conflicts under the …

Risk Analysis Of Highway Nighttime Maintenance Operation Based On Sem, Fan Jinhua, Zou Leping, Qi Shaoren, Tian Zhen

Journal of China & Foreign Highway

In order to analyze the factors affecting the risk of nighttime expressway maintenance operation and quantitatively assess the degree of influence of various factors on the risk of nighttime maintenance operation, this paper extracted five first-level indicators and 36 second-level indicators that affect the risk of operation through literature review, accident data, and questionnaire survey and built an evaluation system. The first-order and second-order confirmatory factor analysis models were constructed by using a structural equation model (SEM) based on 343 questionnaires of the nighttime maintenance operation risks. The results show that the driver factor has the greatest effect on the …

Study On Effectiveness Evaluation Method Of Expressway Drainage System In Rainy Area, Luo Datian, Li Jiayi, Zou Jingrong

Journal of China & Foreign Highway

In order to comprehensively evaluate the effectiveness of expressway drainage systems in rainy areas and comprehensively analyze the factors affecting the effectiveness of drainage systems, this paper took the perfection of drainage system, stability of drainage facilities, and road traffic safety as the first-level evaluation index and six kinds of influencing factors such as the degree of integrity as the second-level index, and it put forward the evaluation criteria of the effectiveness of expressway drainage system in rainy areas. The fuzzy comprehensive evaluation method was used to determine the membership degree of expert scoring through the trapezoid membership function, and …

Research On Crack And Permeability Characteristics Of Cement ⁃Modified Expansive Soil Under Dry ⁃Wet Cycles, Bao Guiyong, Xu Yangshaojun, Jiang Zhijie, Rong Hongliu, Wang Jinlong

Journal of China & Foreign Highway

In order to study the engineering permeability characteristics of cement-modified expansive soil under dry and wet cycles, the mix ratio of cement-modified expansive soil was designed, and the orthogonal design test method was adopted. Image analysis software PACS, unconfined compressive strength test, and laboratory permeability test were used to study the crack development, strength attenuation characteristics, and permeability changes of cement-modified expansive soil under dry and wet cycle conditions. The results show that soil permeability and strength are greatly affected by the number of dry and wet cycles. Under the condition of dry and wet cycles, the moisture content of …

Probabilistic Modeling Of North Atlantic Ocean Hurricane Spawn Considering Climate Change, Susmita Bhowmik, Weichiang Pang, Michael Stoner

Publications

Hurricanes are a significant natural hazard, which cause significant damage and financial losses in the coastal areas of the United States almost every year. For example, the devastating nature of North Atlantic Ocean (NAO) storms can easily be understood from the 2005 Hurricane Katrina, which was the most damaging NAO storm in modern history, causing more than 1,800 deaths and a financial loss of at least 161.3 billion USD. It has been found that the formations of hurricanes depend heavily on climate conditions, which implies a direct relationship between the changes in climate extremes and the occurrences of hurricanes or …

Adsorptive–Photocatalytic Performance For Antibiotic And Personal Care Product Using Cu0.5Mn0.5Fe2O4, Chanat Chokejaroenrat, Chainarong Sakulthaew, Athaphon Angkaew, Apiladda Pattanateeradetch, Wuttinun Raksajit, Kanokwan Teingtham, Piyaporn Phansak, Pawee Klongvessa, Daniel D. Snow, Clifford E. Harris, Steven Comfort

Nebraska Water Center: Faculty Publications

The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu_0.5Mn_0.5Fe₂O₄ nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu_0.5Mn_0.5Fe₂O₄ recrystallized, improving material crystallinity and purity for the adsorptive–photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction …

Optimizing The Membrane-Assisted Recovery Of Solids (Mars) Technology For Nutrient Removal And Recovery From Concentrated Waste Streams, Ben Yamin Hoque

USF Tampa Graduate Theses and Dissertations

The effective management of nutrients, such as nitrogen and phosphorus, in decentralizedwastewater treatment environments is a pressing challenge. These nutrients pose significant risks to the environment and public health when discharged into water bodies, while their recovery and reuse can help alleviate nutrient shortages in various industries, including agriculture. Conventional biological treatment methods used in centralized facilities are not suitable for decentralized systems due to operational complexities and space limitations. Chemical treatment mechanisms, such as adsorption, ion exchange, precipitation, and air-stripping, offer potential solutions but are accompanied by challenges like high costs and logistical issues. Therefore, finding a sustainable and …

Assessment Of Spatial Variability Of Groundwater Levels In Moroto District, Uganda, Augustina Clara Alexander Dr

Tanzania Journal of Engineering and Technology (TJET)

Globally, the variation of groundwater levels is increasingly overwhelming due to over exploitation resulting from population growth. The dynamic nature of socio-economic activities in Moroto District such as agriculture, settlements and increased trends in irrigation technology has been well-known worldwide as common parameters triggering groundwater variability. Nevertheless, determination of groundwater levels for groundwater management and development purpose is a challenge due to spatial variability in levels across Moroto District. In this study, geostatistical technique in Geographical Information System (GIS) was used to analyze spatial variability of water levels in the study area. The analysis utilized ordinary Kriging method to predict …

Incorporation Of Carbon Dioxide Production And Transport Module Into A Soil-Plant-Atmosphere Continuum Model, Sahila Beegum, Wenguang Sun, Dennis Timlin, Zhuangji Wang, David Fleisher, Vangimalla R. Reddy, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Carbon dioxide release from agricultural soils is influenced by multiple factors, including soil (soil properties, soil-microbial respiration, water content, temperature, soil diffusivity), plant (carbon assimilation, rhizosphere respiration), atmosphere (climate, atmospheric carbon dioxide), etc. Accurate estimation of the carbon dioxide (CO₂) fluxes in the soil and soil respiration (CO₂ flux between soil and atmosphere) requires a process-based modeling approach that accounts for the influence of all these factors. In this study, a module for CO₂ production via root and microbial respiration and diffusion-based carbon dioxide transport is developed and integrated with MAIZSIM (a process-based maize crop growth …

Exploratory Data-Driven Models For Water Quality: A Case Study For Tampa Bay Water, Sandra Sekyere

USF Tampa Graduate Theses and Dissertations

Water, a crucial resource for sustaining life, covers approximately 70% of the earth's surface. Nonetheless, the quality of water is deteriorating rapidly due to the rapid growth of urban areas and industries, which is a worrying trend causing harm to human health and the ecosystem. Water quality forecasting has a key role in water resources management by enabling effective pollution control, ecosystem monitoring, and decision-making.

Previously, traditional statistical models were used to forecast water quality, but they were unable to examine the non-linear relationships between water quality parameters, and they assumed that all datasets were distributed normally. This study uses …

Characteristics And Hydraulic Behavior Of Adsorptive Media For Use In Permeable Reactive Barriers, Shelby Rocha

USF Tampa Graduate Theses and Dissertations

The Cargill ditch is located on the property of Se7en Wetlands, a 1600-ac treatment wetland system in Lakeland, Polk County, Florida. The Se7en Wetlands property was previously utilized for phosphate mining prior to the construction of the system. Nonpoint nutrient sources derived from remnants of abandoned phosphate mines – known as “legacy phosphorus” – become mobilized by stormwater runoff and impair surface water bodies by promoting harmful algal blooms (HABs). Thus, the Cargill ditch likely conveys nutrient rich flow resulting from legacy phosphorus and is thought to be one contributing factor in the occurrence of HABs within the treatment wetland …