Civil and Environmental Engineering Commons^™

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 …

Digital Challenges And Opportunities Of Addressing On-Site Productivity And Safety On Construction Job Sites: An International Perspective, Ahmed Hassan, Ankur Mitra, Mark Mulville, Alan Hore

Conference papers

The slow pace of digital transformation in construction remains an impediment to the industry’s evolution. Despite rapid developments in digital technologies, the vast bulk of data generated on construction job sites remains underutilised due to the limited use of real-time data capture. The diffusion of digital solutions in construction depends on successfully capturing critical real-time data that can inform and contribute to more productive work patterns and safer job sites. Nevertheless, the construction industry’s fragmented nature has segregated the digital solutions offered by technology providers from the volatile challenges facing on-site construction practitioners.

This paper will present the early development …

Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan

LSU Master's Theses

Mangrove forests can be found along the world’s intertidal tropical and sub-tropical coastlines. These forested wetlands provide many ecosystem services, including supporting coastal food chains, trapping sediment, and shoreline stabilization. Mangroves are also known for flood damage mitigation by dissipating waves and surge during flooding events. Thus, coastal communities declare a vested interest in the performance of the forest to mitigate flood damage. Physical models using artificial mangrove structures have shown that red mangrove-dominated fringe forests can protect built infrastructure by reducing wave height due to increased drag. One way to estimate the contribution of red mangrove (Rhizophora mangle) prop …

Size Effects In Additively Manufactured Inconel-718 Thin Elements And Cellular Structures, Reem Abdelkarim Abo Znemah

LSU Doctoral Dissertations

A current focus in the additive manufacturing (AM) research community is the production of complex shaped metallic parts and cellular structures. Many researchers went on analyzing and simulating these structures without considering the effect of the element thickness and heterogeneous printing parameters on the resulting material behavior. To advance the application of laser powder bed fusion (LPBF), an AM process, in producing Inconel718 (IN718) complex shaped parts and cellular structures, this study aimed to investigate the effect of thin-walled elements thickness on the mechanical characteristics of both the individual elements and overall cellular structure. A multiscale experimental evaluation of the …

Exploration Of Efficient Dewatering Methods In Stimulus-Responsive Hydrogels And Their Potential For Desalination, Weiliang Sun

LSU Doctoral Dissertations

Addressing global freshwater scarcity is a pressing challenge, and desalination has emerged as a viable solution to generate high-quality water without compromising natural freshwater ecosystems. In comparison to conventional desalination methods such as thermal distillation and membrane-based processes, hydrogels offer distinct advantages including strong water absorption, water retention, well-defined pore structures, customizable functional groups, and responsive properties to external stimuli. These unique characteristics position hydrogels as promising candidates for water treatment applications. Hydrogel-based desalination involves the utilization of hydrogels to absorb water from saltwater, and then discharge low-concentration solutions to obtain reclaimed water. The fundamental principle underlying the desalination ability …

Effect Of Internal Curing And Shrinkage-Mitigating Materials On Microstructural Characteristics Of Fiber-Reinforced Mortar, Kamran Aghaee, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Internal curing (IC) and other shrinkage mitigating materials are employed to reduce shrinkage and risk of cracking. This study investigates the efficiency of individual versus combined use of IC and shrinkage mitigating materials on key characteristics of fiber-reinforced mortar (FRM). The investigated mixtures include a 25% pre-saturated lightweight sand (LWS) that is added individually and combined with 10% CaO-based expansive agent (EA) and 2% shrinkage reducing admixture (SRA). This elucidates the synergistic effect of high content IC and EA/SRA on macro- and micro-mechanical characteristics of FRM, especially at the interface of the matrix with fibers. Mechanical properties, microstructural characteristics, and …

Triverus Infiltration And Cleaning Report 2023, Unh Stormwater Center

UNH Stormwater Center

No abstract provided.

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 …

Development Of A Covid-19 Vulnerability Index (Cvi) For The Counties And Residents Of New Jersey, Usa., Remo Disalvatore, Sarah K Bauer, Jeong Eun Ahn, Kauser Jahan

Henry M. Rowan College of Engineering Departmental Research

The coronavirus disease 2019, or COVID-19, has impacted countless aspects of everyday life since it was declared a global pandemic by the World Health Organization in March of 2020. From societal to economic impacts, COVID-19 and its variants will leave a lasting impact on our society and the world. During the height of the pandemic, it became increasingly evident that indices, such as the Center for Disease Control's (CDC) Social Vulnerability Index (SVI), were instrumental in predicting vulnerabilities within a community. The CDC's SVI provides important estimates on which communities will be more susceptible to 'hazard events' by compiling a …

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) …

Crashworthy Perforated Square Steel Tube (Psst) Mailbox Support – Phase I, Robert W. Bielenberg, Cody S. Stolle, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

Federal requirements have made it mandatory that safe mailbox support systems be designed to yield or breakaway whenimpacted by a vehicle. The Nebraska Department of Transportation (NDOT) has previously used a non-proprietary, U-channel post mailbox support that was evaluated at the Midwest Roadside Safety Facility (MwRSF) in the 1980's. NDOT desires that the mailbox support be updated to meet MASH 2016 TL-3 safety performance criteria and be redesigned to use perforated square steel tubing (PSST) for the mailbox support post.

The objective of this research project is to develop a non-proprietary mailbox support using PSST support posts that is MASH …

Public Sector Bim Adoption: Development And Evaluation Of Government Policy Interventions: A Systematic Literature Review, Shiyao Kuang, Alan Hore, Ahmed Hassan, Barry Mcauley, Roger West

Conference Papers

Rapid technological advancements in the Architecture, Engineering and Construction (AEC) sector have provided a significant opportunity for improving the industry's efficiency, performance and sustainability. Building Information Modelling (BIM) is an innovative approach to information management in construction that provides a structured methodology for storing and analysing building information exchanged between project stakeholders. However, successful interventions and supports introduced by the public sector in accelerating BIM adoption can be seen through BIM mandates, promotion of information management ISO standards, guidance, funding and procurement integration. In this study, a systematic literature review is adopted to identify BIM policy interventions. The study aims …

Increasing The Impact Of Utah State University's Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio

Reports

Study Goal – Increase the volume of water saved by the Utah State University (USU) Extension landscape Water Check program because outdoor water use is the largest component of residential use with the largest opportunity to reduce use. We used 5-second water use data collected with Flume Smart Home Water Monitoring devices (Figure 1) at residential homes before and after a Water Check (Box 1; Figure 2) to answer four questions:

1. How much water did households save?
2. Which Water Check recommendations did participants implement?
3. Why did participants implement some recommendations and not others?
4. How to further reduce landscape water use?

Increasing The Impact Of Utah State University’S Extension Water Check Program With 5-Second Metering, Mahmud Aveek, David E. Rosenberg, Camilo Bastidas, Jeffery S. Horsburgh, Belize A. Lane, Kelly Kopp, Peter Mayer, Joe Fazio

Reports

Study Goal – Increase the volume of water saved by the Utah State University (USU) Extension landscape Water Check program because outdoor water use is the largest component of residential use with the largest opportunity to reduce use. We used 5-second water use data collected with Flume Smart Home Water Monitoring devices (Figure 1) at residential homes before and after a Water Check (Box 1; Figure 2) to answer four questions:

1. How much water did households save?

2. Which Water Check recommendations did participants implement?

3. Why did participants implement some recommendations and not others?

4. How to further reduce landscape water use?

Assessing The Impact Of Spatial Resolution Of Uas-Based Remote Sensing And Spectral Resolution Of Proximal Sensing On Crop Nitrogen Retrieval Accuracy, Kianoosh Hassani, Hamed Gholizadeh, Saleh Taghvaeian, Victoria Natalie, Jonathan Carpenter, Jamey Jacob

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Foliar nitrogen (N) plays a central role in photosynthetic machinery of plants, regulating their growth rates. However, field-based methods for monitoring plant N concentration are costly and limited in their ability to cover large spatial extents. In this study, we had two objectives: (1) assess the capability of unoccupied aerial system (UAS) and non-imaging spectroscopic data in estimating sorghum and corn N concentration and (2) determine the impact of spatial and spectral resolution of reflectance data on estimating sorghum and corn N concentration. We used a UAS and an ASD spectroradiometer to collect canopy- and leaf-level spectral data from sorghum …

Residential Building Flood Risk Assessment And The Benefits Of Home Elevation, Ayat Al Assi

LSU Doctoral Dissertations

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars is needed to provide valuable information for stakeholder decision-making inside and outside the special flood hazard area (SFHA, which corresponds to the 100-year floodplain). To further inform flood mitigation strategies, quantifying flood risk reduction with home elevation above an initial first-floor height (FFH₀) and the cost effectiveness of federal mitigation assistance for elevation are important steps to enhance awareness of the effect of elevation in reducing flood risk. …