Digital Commons Network^™

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 …

Characterizing Wind-Wave Flow Physics And Loading Effects On Power Transmission Systems And Offshore Wind Turbines, Tianqi Ma

LSU Doctoral Dissertations

Recent extreme hurricanes caused extensive damage to critical civil infrastructure. Accurate modeling of the extreme complex wind fields and coupled wind-wave fields is essential to quantify the single wind or combined wind-wave loading effects on the structures. This research aims to characterize wind and wind-wave flow physics to quantify the loading effect on power transmission systems and offshore wind turbines.

First, a microscale (∼km) high-fidelity high-resolution computational model is developed to simulate hurricane wind fields with detailed physics. The generated wind field is applied to analyze the structural response of a power transmission system. The proposed hurricane boundary layer (HBL) …

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 …

Exploration Of Shared Passenger Urban Air Mobility – Integrated Network Design, Operation Scheduling And System Configuration, Zhiqiang Wu

USF Tampa Graduate Theses and Dissertations

Urban air mobility (UAM) is an emerging concept proposed in recent years that uses electric vertical take-off and landing vehicles (eVTOLs). UAM is expected to offer an alternative way of transporting passengers and goods in urban areas with significantly improved mobility by making use of low-altitude airspace. Considering the high capital investment of eVTOLs and relative high fee of using UAM passenger service, a viable UAM format is shared passenger service. Such a service is usually station-based, i.e., with vertiport located in popular sites where potential passengers can access. To understand the viability of such use cases, the vertiport owners …

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 …

Exploring The Determinants Of Organic Matter Bioavailability Through Substrate-Explicit Thermodynamic Modeling, Firnaaz Ahamed, Yaqi You, Amy Burgin, James C. Stegen, Timothy D. Scheibe, Hyun-Seob Song

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Microbial decomposition of organic matter (OM) in river corridors is a major driver of nutrient and energy cycles in natural ecosystems. Recent advances in omics technologies enabled high-throughput generation of molecular data that could be used to inform biogeochemical models. With ultrahigh-resolution OM data becoming more readily available, in particular, the substrate-explicit thermodynamic modeling (SXTM) has emerged as a promising approach due to its ability to predict OM degradation and respiration rates from chemical formulae of compounds. This model implicitly assumes that all detected organic compounds are bioavailable, and that aerobic respiration is driven solely by thermodynamics. Despite promising demonstrations …

Experimental Study: The Effect Of Pore Shape, Geometrical Heterogeneity, And Flow Rate On The Repetitive Two-Phase Fluid Transport In Microfluidic Porous Media, Seunghee Kim, Jingtao Zhang, Sangjin Ryu

Department of Civil and Environmental Engineering: Faculty Publications

Geologic subsurface energy storage, such as porous-media compressed-air energy storage (PM-CAES) and underground hydrogen storage (UHS), involves the multi-phase fluid transport in structurally disordered or heterogeneous porous media (e.g., soils and rocks). Furthermore, such multi-phase fluid transport is likely to repeatedly occur due to successive fluid injections and extractions, thus, resulting in cyclic drainage–imbibition processes. To complement our preceding study, we conducted a follow-up study with microfluidic pore-network devices with a square solid shape (Type II) to further advance our understanding on the effect of the pore shape (aspect ratio, Type I: 5–6 > Type II: ~1), pore-space heterogeneity (coefficient of …

Improved Burned Area Mapping Using Monotemporal Landsat-9 Imagery And Convolutional Shift-Transformer, Seyd Teymoor Seydi, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Satellite imagery, specifically Landsat, have been widely used for mapping and monitoring wildfire burned areas. The new Landsat-9 satellite – with higher radiometric resolution compared to its predecessors, and improved temporal resolution when combined with Landsat-8 (∼8 days) – enables a wide range of applications, particularly burned area mapping (BAM). We propose a novel deep learning BAM model that leverages the strengths of the convolutional layers for deep feature generation from Landsat-9 imagery and shift-transformer block for burned area classification. The performance of the model is evaluated in five large fire case studies across the globe. BAM results are also …

Modeling Cyanotoxin Production, Fate, And Transport In Surface Water Bodies Using Ce-Qual-W2, Bernadel Rose Hintz Garstecki, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Cyanobacteria are frequently associated with forming toxic blooms. The toxins produced by cyanobacteria, cyanotoxins, are harmful to both humans and animals. Rising temperatures due to global climate change are expected to increase the occurrence of cyanobacteria, and it is vital that we protect our drinking water supplies and natural water resources. Modeling the production, fate, and transport of these toxins is an important step in limiting exposure to them and evaluating management strategies to mitigate their impact. The research provided here offers an overview of some of the main cyanotoxins of concern and presents preliminary models for the transport and …

A Data-Driven Method For Damage Detection In An Open Deck Steel Truss Railroad Bridge Under The Moving Train Load, Mahesh Pokhrel

Theses and Dissertations

Open-Deck (OD) steel truss railroad bridges are one of the most common types of railroad bridges in the United States. They are, however, significantly vulnerable to the dynamic effects of moving train load. In the long run, these dynamic effects cause fatigue damage to the structural members. The damage in most of the railroad bridges are monitored by visual inspections which are sometimes unreliable and inconsistent due to human error. This study explores the identification and classification of damage to an open deck railroad bridge from both time-domain (statistical features) and time-frequency domain features (Hilbert-Huang Transform) extracted through acceleration response …

Using Machine Learning And Distributed Hydrologic Modeling To Predict Soil Texture, Surface Soil Moisture And Evapotranspiration In Jornada Experimental Range, Southwestern U.S., Jorge Andres Mayo

Open Access Theses & Dissertations

In water-limited ecosystems, detailed knowledge of the soil, vegetation, and atmosphere interactions is critical to understand the processes that control the partitioning of energy, water fluxes, and biogeochemical cycles within the critical zone. This Master's thesis is divided into two main contributing sections. The first, is on the use of machine learning to reconstruct missing soil type information, and the second, on the calibration and validation of a physically-based distributed hydrological model to estimate soil moisture and evapotranspiration within the Jornada Experimental Range of the U.S. in southern New Mexico. For the first contribution, three explainable, shallow machine-learning techniques are …

Development Of Intensity Duration Frequency Curve Of The Lower Rio Grande Valley, Binaya Poudel

Theses and Dissertations

Section 1: This chapter incorporates extensive information about the concept of Intensity-Duration-Frequency (IDF) curves, their historical development and usage, specific focus on the Lower Rio Grande Valley, and the importance of using a comprehensive 32-year data set from 1990-2022 to develop these curves.

Section 2: This chapter provides detailed information about the rigorous comparison of the developed IDF curves with previous ones, where past IDF curves were developed using an empirical formula method. The research presented here employs the Gumbel distribution method, providing a fresh perspective and potentially more accurate predictions of future weather extremes.

Section 3: This chapter outlines …

Building Services Engineering July/August 2023

Building Services Engineering

No abstract provided.

Assessment And Development Of Collaboration Framework For Less-Than-Truckload Carriers, Bhavya Padmanabhan

Theses and Dissertations

The growth of e-commerce is changing consumer expectations for delivery services. Competition is making “faster and cheaper” a nonnegotiable part of success; hence, retailers are seeking carriers that can deliver with ever-shorter lead times and at the lowest possible cost. In this environment, large carriers have a competitive advantage due to their market power. For small-to-medium-sized less-than-truckload (LTL) carriers to stay in business, they must improve their efficiency and lower cost. A potential strategy to achieve these goals is to collaborate with other carriers. In collaborating, carriers would exchange and perform certain jobs for each other to lower their transportation …

Developing A Vision-Based Framework For Measuring And Monitoring Water Resource Systems Using Computer Vision And Deep Learning Techniques, Seyed Mohammad Hassan Erfani

Theses and Dissertations

Increased vulnerability of water systems to extreme events and climate change is among the profound challenges facing the management of water resource systems around the world. Extreme events, including droughts, floods, and natural hazards have become more frequent and intensive, particularly in coastal regions. Floods, for instance, caused tens of billions of US dollars losses and put the lives of thousands in danger, globally. To cope with the adverse consequences of floods, a wide range of structural, non-structural, and emergency measures are studied and deployed by flood management sectors. Various flood simulation, mapping, and forecast systems have been developed to …

A Systems Approach To Design And Plan Sustainable Antifragile Infrastructure Based On Aggregate Footprint And Satisfaction, Farboud Khatami

Theses and Dissertations

The concepts of robustness and sustainability in planning and design of water and energy infrastructures have been extensively explored in previous research, primarily focusing on system reliability, environmental considerations, and economic aspects. This study aims to broaden the understanding of these concepts by offering comprehensive frameworks that capture the essence of robustness and sustainability at two distinct levels.

The first level of investigation focuses on the performance of infrastructure networks during natural disasters. Traditionally, this has been addressed using reliability, resilience, and vulnerability metrics. However, these methods rely on static, deterministic, and non-stationary data, which is inadequate when dealing with …

Streamwise And Vertical Dispersal Of Tracer Stones From A Continuously Supplied Source, Amanda Grace Balkus

Theses and Dissertations

Individual movement of sediment grains is oftentimes studied with the use of tracer stones. Studies performed both in the field, in the laboratory and with numerical models involve installing a patch of stones (tracers) on the bed surface and rarely deep in the deposit. Once installed, particle displacement is monitored over time scales varying from one flood to several years. These studies are useful, for example, to study bedload transport dynamics, understand contaminant fate and transport as well as to identify and define stream restoration practices (e.g. quality of fish habitat). Here we use a vertically continuous model to study …

The Influence Of Bio-Inhibitor On The Corrosion Resistance Of Reinforced Concrete Beams Containing Mswi-Ba As A Partial Sand Replacement, Jamal Khatib, Israa Amer, Ghanem Hassan, Adel Elkordi

BAU Journal - Science and Technology

In this paper, the corrosion behavior of reinforced concrete beams containing municipal solid waste incineration bottom ash (MSWI-BA) as a partial sand replacement and Ceratonia siliqua extract as a green corrosion inhibitor was investigated. Four mixes were prepared: (0 and 20% replacement of sand by MSWI-BA with and without Ceratonia siliqua extract). Tests conducted were UPV, compressive strength, split tensile strength, and elastic modulus. RC beams were prepared for determining the flexural performance. Eight beams were casted. Four beams were exposed to accelerated corrosion test and four beams were kept at room temperature. It was found that the compressive strength, …

Analysis Of Evolution And Morphology Of Urban And Road Networks: Case Study Lebanon-Nabatiyeh Area, Amal Al Ghorayeb, Adel Elkordi, Ghaleb Faour, Zeinab Jaber, Youssef Attallah

BAU Journal - Science and Technology

This study examines the morphology and evolution of urban and road networks and their relationship with topography in the Lebanon-Nabatiyeh area, by using GIS and remote sensing data. and calculate the annual urban growth percentage rate. The results reveal a clear relationship between the morphology of urban and road networks and their evolution over four periods, as well as the influence of the surrounding topography on their configuration. The study recommends that urban areas should be developed in areas with a slope range of 15º or more to improve the urban structure and infrastructure surrounding them. Understanding the evolution and …