Digital Commons Network^™

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 …

Accommodating Spatio-Temporal Dependency In Airline Demand Modeling, Sudipta Dey Tirtha, Tanmoy Bhowmik, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

The objective of the current study is to examine monthly air passenger departures at the airport level considering spatial interactions between airports. In this study, we develop a novel spatial grouped generalized ordered probit (SGGOP) model system of monthly air passenger departures at the airport level. Specifically, we estimate two variants of spatial models including spatial lag model and spatial error model. In the presence of repeated demand measures for the airports, we also consider temporal variations of spatial correlation effects among proximally located airports by employing space and time-based weight matrix. The proposed model is estimated using monthly air …

Comprehensive Understanding Of Factors Impacting Competitive Construction Bidding, Muaz O. Ahmed, Islam H. El-Adaway, Aubrie Caldwell

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction competitive bidding has been studied by many researchers; however, their focus was mainly on certain bidding aspects. Thus, despite their value, existing bidding models have limited applicability for various reasons including the non-inclusion of some real-life factors that impact bidding-related decisions. As such, there is a need for identifying a comprehensive list of bidding factors that impact construction bidding-related decisions, studying their associations, and identifying understudied factors to direct future research efforts. This paper fills this knowledge gap. First, the authors conducted a systematic selection of 124 construction bidding-related articles published within the past 40 years. Second, the authors …

Risk–Reward Share Allocation Under Different Integrated Project Delivery Relational Structures: A Monte-Carlo Simulation And Cooperative Game Theoretic Solutions Approach, Radwa Eissa, Mohamad Abdul Nabi, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sharing of risks and rewards is considered to be one of the key benefits and principles of integrated project delivery (IPD). Despite its importance, risk–reward strategies are not implemented widely in IPD construction projects due to the lack of a well-defined basis for establishing adequate allocation plans. This paper fills this knowledge gap. This research followed a multistep methodology. First, the authors calculated the risk control valuations of all potential combinations of coalitions for IPD stakeholders. This was performed using interrelated steps of risk identification and quantification, risk assignment based on associated contractual analysis, establishment of a coordination network, and …

Multifunctional Models In Digital And Physical Twinning Of The Built Environment—A University Campus Case Study, Genda Chen, Ibrahim Alomari, Woubishet Zewdu Taffese, Zhenhua Shi, Mohammad Hossein Afsharmovahed, Tarutal Ghosh Mondal, Son Nguyen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Digital Twin (DT) Concept Has Been Developed for a Single Function in Previous Studies. This Study Aims to Empower DTs with a Layered Integration of Multifunctional Models in the Built Environment. It Develops a Framework of DT Modules in Three Hierarchical Tiers: Region, Asset, and System; Defines a New Concept of the Degree of Digital Twinning (DODT) to the Real World by the Number of Models Enabled by a Common DT Platform; and Enables Spatiotemporal Analysis in Multiple Scales to Couple Nonstructural with Structural Building Components and Connect the Built Environment to Planning Constructions. While the Asset and System …

Elasto-Plastic Behavior Of Single-Story Single-Bay Orthogonal Steel Space Frame Under Angular Earthquake, Mohammad Hamayoun Stanikzai

Civil & Environmental Engineering Theses & Dissertations

A study of the elasto-plastic behavior of single-story single-bay orthogonal steel space frame under an angular earthquake ground motion is investigated. The building frame is subjected to a horizontal earthquake ground motion not aligned with the building’s principal axes. Such a frame can develop biaxial bending and torsion in its members. The governing differential equations of equilibrium for the typical biaxially loaded sway beam-column are presented and iteratively solved using a finite-difference scheme. The effects of warping and residual stresses are accounted for in the analysis. The equations are used to predict the quasi-static elasto-plastic response of the frame when …

Stability And Strength Of Glass Frp Beam-Columns With Biaxial Bending And Torsion Including Shear And Warping Deformations, Emad M. Amin

Civil & Environmental Engineering Theses & Dissertations

Presented herein is a study of the stability and strength of pultruded glass fiber reinforced polymer (Glass FRP) beam-columns with an I-shaped cross section subjected to biaxial bending and torsion including shear and warping deformations. Three coupled differential equations of equilibrium including second-order effects and geometric imperfections are formulated and solved using a finite-difference scheme. Laboratory experiments are also conducted on glass FRP members with applied torsion; axial load; combined axial load with biaxial bending; and combined axial load, biaxial bending and torsional moment, respectively, for comparison to the theoretical predictions. The theoretical results agreed well with the experiments for …

Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a study of the dynamic soil-structure interaction response of tapered wood utility poles embedded in various foundation soils subject to quasi-static and dynamic wind loads. The study includes the effects of nonlinear soil behavior with varying quantities of moisture and nonlinear cable tension loads on a class H1 wood pole. The natural frequency response of the pole is determined using a finite element formulation. The dynamic response in the presence of wind-induced forcing function is studied using a SAP2000 finite element scheme with wind speeds up to 220 mph. The natural frequency of the …

10 Meters To Disaster: The Challenges Of Premature Application Of Circular Economy Strategies In Jakarta’S Waste Management Structure, Almira Bowo

Independent Study Project (ISP) Collection

Jakarta's complex issue of waste management encompasses a multitude of challenges that include inefficiencies in infrastructure, a lack of public awareness of the consequences of an inadequate waste system, socioeconomic disparities, and a deficiency in intersectoral collaboration. The urgency for holistic and sustainable solutions that prioritize proactive waste collection is underscored by the complexities of these dynamics. This field study paper argues that the attention that is being drawn towards trending waste management innovations, which are reactive strategies, could bring the waste crisis in Jakarta to an even more critical state. The sections will critically examine current waste management efforts …

Advancing Depth-Storage-Discharge Modeling In Regional Hydrology, Fahad Alshehri

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of an innovative approach to populating rating characteristics and supporting hydrologic modeling, designed to simplify complex real-world hydrological systems and accurately estimate their responses to rainfall, runoff, baseflow and evaporation stresses. The core of this research addresses the challenges inherent in characterizing hydrography elements in hydrologic modeling, particularly in regions lacking comprehensive stream reach survey data, flow and stage. This issue is pronounced in areas with extensive wetland hydrography, where traditional modeling requires intensive manual calibration, and course rating data that are often unavailable. To overcome these challenges, this study introduces a novel procedure that …

Development Of Data-Driven Models To Predict Chemical Dosage And Energy Intensity For Different Supply Sources Of Drinking Water, Rehnuma Salsavil

USF Tampa Graduate Theses and Dissertations

As part of the UN Sustainable Development Goals (SDG6), access to clean water for the entire population and sustainable management of water resources have been stressed. Demand for water is increasing due to population growth, economic development, water quality degradation, and climate change. More water needs to be produced for the community at lower treatment costs. The chemical dosage and energy intensity are two important factors that influence water treatment costs and sustainable management of resources as well.

Previously, chemical dosage modeling to reduce treatment costs have been explored but there have been more focus in coagulant dosage modeling. Other …

Bear Lake Session, Lawrence Culver, Ben Shaw, Wesley Matthis, Mario Harper

Spring Runoff Conference

No abstract provided.

Leveraging Systems Thinking For Global Environmental Health, Martha M. Mcalister

USF Tampa Graduate Theses and Dissertations

Environmental health inequities such as household air pollution, inadequate water, sanitation, and hygiene, and chemical pollution persist globally and have myriad consequences on individual and societal well-being. Unfortunately, while billions of dollars and countless hours of research have been applied towards addressing these issues in development, humanitarian, and environmental justice contexts, attempts to reduce the environmental burden of disease can seem successful at first, but then backslide to pre-intervention conditions (or worse). This is indicative of policy resistance, a tendency of complex systems that makes it very difficult to enact change if the “rules” of the system are misunderstood. There …

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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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, 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 …