Engineering Commons^™

Properties And Application Of Cement Improved Loess Under Low Temperature Environment In Cold Region, Li Xiangyang

Journal of China & Foreign Highway

According to the cold climate and low annual average temperature in cold regions of China，the field curing conditions of cement improvement of collapsibility loess under low temperature，room temperature，and medium temperature were simulated at 5 ℃，10 ℃，20 ℃，and 30 ℃，respectively.Based on laboratory experiments，this study analyzed the effects of curing temperature，cement content，and curing age on RCBR，unconfined compressive strength，and dynamic resilience modulus of cement improved loess.The effects of cement content and curing temperature on freeze-thaw durability and erosion resistance of cement improved loess were studied by the freeze-thaw cycle test and dynamic water erosion test.Combined with the laboratory results，the 4% and 5% cement …

Effect Of Chloride Ions On Salt Expansion Of Salinized Subgrade Fill Soil In Cold Regions, Hu Wenzhu, Wang Zhaowei, Cao Yong, Zhang Jing, Bai Ruiqiang

Journal of China & Foreign Highway

Salinized subgrade fill soil in cold regions typically comprises composite saline soil rich in sodium chloride and sodium sulfate.This study aimed to explore the mechanism of the effect of chloride ion content on salt expansion of the salinized subgrade in cold regions.Based on the calculation theory of the sodium chloride-sodium sulfate-water ternary system solution in the Pitzer ion model and combined with the FREZCHEM model，the study quantitatively analyzed the intrinsic connection between water activity，freezing factor，and supersaturation ratio with temperature and concentration ratio （η=mCl-/mSO2-4）.It investigated the variation patterns of the freezing temperature and crystallization supersaturation ratio of composite saline soil with …

Correlation Between Pavement Distress And Structural Hidden Distress, Liu Xianming, Xia Han, Hu Dongping, Yan Chen, Yang Rui, Zhong Xinran

Journal of China & Foreign Highway

The hidden distress in the pavement structure does great harm to the performance and service life of the road.In this work，based on the statistical idea of pavement distress rate in the Highway Performance Assessment Standards （JTG 5210—2018），an index of characterizing hidden distress in the pavement structure，namely pavement structure distress rate，was proposed.Based on the actual highway inspection project，the pavement distress and the hidden distress in the depth of 1 m below the pavement of a two-way four-lane highway with a length of 38 km were studied.The overall situation of pavement distress and hidden distress and their spatial distribution were analyzed statistically …

Structural Repair And Performance Evaluation Of Aged Sbs Modified Asphalt, Xu Guang, Li Qishi, Kuang Huaping, Zhang Henglong, Zhou Ruibo, Chen Yanmei

Journal of China & Foreign Highway

To rejuvenate the excellent performance of aged styrene-butadiene-styrene （SBS） modified asphalt，colza oil bio-asphalt （COA） and polymethylene polyphenyl isocyanate （PAPI） were used in this study for adjusting the asphalt components and repairing SBS molecular structure，respectively.The above-mentioned dual regeneration mechanism was verified by comparing the effects of different rejuvenation components on the physical and rheological properties，as well as the molecular weight distribution of short-term aged SBS modified asphalt.Moreover，according to the change law of rheological properties of unaged base asphalt and SBS modified asphalt under the effect of dual regeneration agent，the influence of the regeneration agent on the phase angle platform area was …

Vessel Collision Force And Anti‑Collision Performance Of Long‑Span Beam‑Arch Composite Rigid Frame Bridge, Zhang Wenming, Wang Zhiwei, Lai Yaping

Journal of China & Foreign Highway

Beam-arch composite rigid frame bridge is a new bridge type，and it has few vessel collision studies.By taking the Lijia Jialing River Bridge as the engineering background，the standard value of vessel collision force and anti-collision performance of the long-span beam-arch composite rigid frame bridge were studied.After determining the representative vessel type and vessel collision calculation conditions，the vessel-bridge collision processes of the single-pier models under various calculation scenarios were simulated by using ANSYS/LS-DYNA nonlinear finite element transient dynamic software.The simulation results of collision forces were compared with the results of several empirical formulas.Finally，the full bridge model and the ultimate bearing capacity of …

Installation And Connection Mode Of Stiffening Beam Segment Of Steel Truss Suspension Bridge, Chen Changsong, Wu Junjie

Journal of China & Foreign Highway

During the construction of long-span steel truss suspension bridges，the main girder can be connected in segment-by-segment articulated connection method and rigid-articulated connection combination method.Taking a Yangtze River Highway Bridge in Hubei Province as an example，this paper established the plane calculation model of the full bridge using the Bridge Design and Construction Monitoring System BDCMS to simulate the above two connection methods of the main girder in construction.From the comprehensive analysis of chord member internal forces and line shape of the stiffening beam，this paper finds that the rigid-articulated connection combination method is more appropriate in the construction.In addition，this paper researched the …

Seismic Responses Of Cable‑Sta Yed Bridge Considering Ponding Effect Under Near‑Fa Ult Ground Motions, Lyu Long, Yu Deen, Yuan Yuhang, Yang Huaiyu

Journal of China & Foreign Highway

To study the influence of the pon ding e ffect on seismic responses of the cable-stayed bridge under near-fault ground motions，taking a double-tower cable-stayed bridge as the engineering background，this paper analyzed the ponding response of the main bridge and the main beam of the approach bridge of the cable-stayed bridge under near-fault ground motions and the influence of the ponding response on the structural seismic response.Besides，the influence of viscous dampers and elastic cables on the ponding effect of the cable-stayed bridge under near-fault ground motions was studied，which was compared with the seismic response of the cable-stayed bridge under far-fault ground …

Multi‑Dimensional And Multi‑Point Random Seismic Response Analysis Of Long‑Span Cable‑Stayed Bridges At Different Sites, Shi Yi, Lu Lu, Fan Shuli, Shen Meng, Zuo Chunyuan, Sun Xinguo, Cao Feifei

Journal of China & Foreign Highway

To study the random seismic response of long-span cable-stayed bridges at different sites，the site transfer function was used to evaluate the influence of different site conditions on ground motion propagation.By considering the traveling wave effect and the coherence effect，the multi-point power spectrum under different site conditions was generated.By using the pseudo excitation method for solving the absolute displacement，the seismic responses of cable-stayed bridges under uniform excitation and multi-dimensional and multi-point excitation at different sites were compared.A long-span cable-stayed bridge was selected as an example，and Ansys finite element software was used to analyze the random seismic response of the bridge.By considering …

Rigid Domain Optimization Of Steel Truss Joint With Reference To Multi‑Scale Model, Liu Gaocheng, Liu Jian, Dong Chuangwen, Li Chuanxi

Journal of China & Foreign Highway

The rigidity enhancement effect of the integral gusset plate is often simulated in the calculation of an integral nodal steel truss bridge by using a beam element with a rigid arm to improve the calculation accuracy.By taking Zhongshan Lianshwan Bridge as the engineering background，an optimization method based on a multi-scale truss model for nodal rigid domain simulation was proposed and verified.Five consecutive standard sections were selected as the study objects，and the beam element model with rigid arm and the multi-scale model of gusset plate substructure were established by using Ansys.The same boundary and loading conditions were applied.The deflection of the …

Impact Resistance Of Ecc Pipe Piles Based On Ls‑Dyna, Zeng Qingyou, Ye Chenfeng, Liu Junjun, Feng Kai, Cheng Peiyuan, Chen Weihong

Journal of China & Foreign Highway

To study the impact resistance of Engineering Cementitious Composite （ECC） pipe piles，this paper used ANSYS/LS-DYNA to simulate the impact of a vertical drop hammer on the pipe piles.The HJC constitutive model of ECC was established based on key parameters obtained from static tension and compression tests and dynamic compression tests.The correctness of the finite element model was verified by split Hopkinson Pressure Bar （SHPB） tests.The parametric analysis conducted on the pipe pile models compounded with different hammer mass and impact velocity yielded dynamic responses including the displacement，time-history curve of energy，and effective plastic strain diagrams of the pipe piles under various …

Comparative Study Of Different Ventilation Methods During Tunnel Construction, Yue Kun, Bao Xiaohua, Ao Xiang, Liu Kuan, Wu Han, Li Tao, Shen Jun

Journal of China & Foreign Highway

The continuous improvement of tunnel construction technology brings a rapid increase in the speed and mileage of tunnel excavation，during which ventilation is a main problem affecting construction efficiency and safety.Taking the Zhuhai Xingye Express （West Line ） tunnel project as an example，this paper studied the influences of forced ventilation，exhaust ventilation，and hybrid ventilation on the dilution and discharge of harmful gas CO near the tunnel face and the wind speed in the tunnel.The results show that hybrid ventilation performs better in CO dilution，while exhaust ventilation has higher CO emission efficiency with a lower wind speed near the working face.Therefore，although forced ventilation …

Stability Of Excavation Face Of Double‑Mode Shield In Earth Pressure Mode Crossing Fault Zone Of Pearl River, Tong Bin, Zhang Bin, Zhu Hanbiao, Wang Shuying

Journal of China & Foreign Highway

In view of the stability of the excavation face of the double-mode shield crossing the fault zone of the Pearl River，the project of the section from Hongshengsha Station to Yufengwei Station of the second phase of Guangzhou Metro Line Seven was studied.Through numerical simulations conducted to analyze the whole area and the local high-risk area of the shield crossing the fault zone of the Pearl River，this paper explored the construction risk of the shield crossing process.Besides，this paper analyzed the influence of different support stresses and grouting pressures on the stability of the excavation face and ground deformation，and finally，the tunneling parameters …

Development Trend On Raw Materials Market Of Ready‑Mixed Concrete Under Green Construction, Ding Hu, Ding Qingjun, Lin Haojun, Zhang Zhen

Journal of China & Foreign Highway

In the face of resource depletion，high energy consumption in production，high carbon emissions，and serious pollution brought by traditional pumpcrete raw materials，a variety of new raw materials have been gradually developed and promoted to conform with the green construction promoted by China ’s civil engineering industry，witnessing a stable increase in quality，output，and social recognition.High-quality natural river sand and pebbles are in short supply at the origin，and they can be explored in old silted river channels.Gravel and manufactured sand produced using large particle size natural pebbles，limestone，construction waste，and others as raw materials will become new substitutes.In the transformation and upgrading of production enterprises which tend …

Single Nanobubble Formation On Au Nanoelectrodes And Au@Ws2 Nanoelectrodes: Voltammetric Analysis And Electrocatalysis, Xian-Zhun Luo, Xiao-Hu Chen, Yong-Xin Li

Journal of Electrochemistry

Taking advantage of the extremely small size of the gold nanodisk electrode, the single hydrogen nanobubble generated on the surface of the nanoelectrode was studied to evaluate its hydrogen evolution performance. It was found that compared with the bare gold nanodisk electrode, the bubble formation potential of the gold nanodisk electrode modified with tungsten disulfide quantum dots (WS₂ QDs) on the surface was more positive, indicating that its hydrogen evolution activity was higher. Microdynamic model analysis shows that the average standard rate constant of the rate-determining step of the hydrogen evolution reaction of gold nanoelectrodes modified with WS_{2 …}

10.28.2024 Orsp Connect, Liz Williamson

ORED Newsletter

ORSP Name Change

RED Talk

Businesses Invited to a Day With NASA

LINC Door Prize Winners

Review Of Snow And Ice Melting Techniques For Road And Bridge In Cold Regions, Tang Liyun, Shao Haitao, Tang Huaming, Qiu Peiyong, Du Xiaoqi, Zhang Lei, Peng Hui

Journal of China & Foreign Highway

Snow and ice melting of road and bridge surfaces is crucial for traffic safety，but current research on snow and ice melting techniques mainly focuses on engineering effects and technical evaluation，without the analysis and elaboration from the perspective of their mechanisms.To this end，based on the different mechanisms，this study divided snow and ice melting techniques into three types and summarized them：passive deicing，active deicing，and energy utilization deicing.This study systematically evaluated the advantages and disadvantages of traditional deicing methods such as deicing agents and mechanical deicing，analyzed two active deicing techniques，namely inhibitive freezing pavement and phase change material pavement，discussed the environmental-friendly method for road deicing …

Post‑Evaluation Method For Decision‑Making And Implementation Of Highway Maintenance Projects Based On Ahp‑Dematel, Yu Wei, Yang Na, Li Jue

Journal of China & Foreign Highway

Addressing the current lack of post-evaluation management systems related to highways，particularly highway maintenance，this paper proposed a post-evaluation method for the decision-making and implementation of highway maintenance projects based on the combination of analytic hierarchy process （AHP） and decision-making trial and evaluation laboratory （DEMATEL ）.After building a post-evaluation model for the decision-making and implementation of highway maintenance projects and designing the evaluation process，this paper calculated key factors influencing the post-evaluation of the decision-making and implementation of highway maintenance projects and their respective comprehensive weights.The research results indicate that decision-making can possess higher accuracy and efficiency under the above calculation method，providing a …

Bipolar Ionization Did Not Reduce Airborne Bacteria In A Lecture Hall, David A. Kormos, Nishit J. Shetty, Elliott T. Gall, Aaron J. Prussin, Amy Pruden, Linsey C. Marr

Mechanical and Materials Engineering Faculty Publications and Presentations

Ionization treatment of indoor air has attracted attention for its potential to inactivate airborne pathogens and reduce disease transmission, yet its real-world effectiveness remains unverified. We evaluated the impact of an in-duct, bipolar ionization system on airborne particles, including culturable bacteria, in a lecture hall. The ionizer was off with variable fan speed for 1 week, on with variable fan speed for a second week, and on with high and constant fan speed for a third week. We measured ion concentrations and aerosol particle concentrations, and we collected bioaerosol samples for analysis of 16S rRNA gene copies representing total bacteria …

Automation, Improvement, And Sensitivity Analysis Of 3d Parameterized Maize Stalk Models, Joseph Steven Carter

Theses and Dissertations

Maize is the most grown crop in the world. Each year, 5% of maize is lost due to a phenomenon known as stalk lodging (breakage of the stalk below the ear). One of the most promising solutions to stalk lodging is to design stalks with superior geometry to increase stalk strength. Researchers have developed a 3D parameterized maize stalk model, but these models take a long time to structurally analyze and are missing important material properties. This thesis addressed these problems by developing an automated package for analyzing the 3D parameterized maize stalk model, and by measuring the longitudinal shear …

Multiscale & Multiphysics Model Of Damage In Lithium-Ion Batteries, Edris Akbari

LSU Doctoral Dissertations

The demand for safer and more reliable lithium-ion batteries (LIBs) in electric vehicles has increased significantly, especially in addressing mechanical failures like internal short circuits (ISCs), which can lead to thermal runaway. This research investigates the mechanical behavior and damage mechanisms in lithium-ion pouch cells through a multiscale and multiphysics approach, focusing on Lithium Nickel Manganese Cobalt Oxide (NMC) and Lithium Iron Phosphate (LFP) batteries.

The study involved quasi-static and dynamic mechanical tests, including indentation and high-speed penetration, to evaluate stress-strain responses and fracture behaviors. Anisotropic mechanical properties were measured for individual battery components (anode, cathode, separator, and shell) using …

Design Of End Bent Piles For Downdrag, Tanna Frye

USF Tampa Graduate Theses and Dissertations

Embankments are commonly used for bridge approaches, with mechanically stabilized earth (MSE) walls being the preferred choice in Florida. However, the construction of embankments leads to the settlement of the underlying soil, regardless of soil type. When piles are driven before embankment construction, the initial settlement of the original soil creates relative movement between the pile and the surrounding soil, introducing frictional forces. When the existing soils move downward relative to the pile, a downward-oriented side shear known as downdrag is introduced. While downdrag is addressed in current codes and textbooks, it is often only briefly mentioned and primarily in …

Design Of Mathematical Model For Surface Roughness: Optimizing Rsm Through Process Parameters In Machining, Mevludin Shabani, Xhemajl Mehmeti

UBT International Conference

This research paper presents the design of mathematical model aimed at optimizing surface roughness, with a specific focus on the mean width of surface profile peaks (Rsm) during turning operations. It identifies cutting speed and feed rate as critical factors influencing Rsm, highlighting that feed rate exerts the most significant impact on surface quality. Increased feed rates result in coarser finishes due to greater distances between the cutting tool's contact points, whereas lower feed rates yield smoother surfaces. The study also explores how variations in feed rate can affect machining stability, leading to issues such as vibration, tool engagement challenges, …

Innovative Use Of Load Cell Technology For Analyzing Strength Of Plastic Shopping Bags: A Case Study, Ylli Rexhaj, Redon Rexhepi, Fidan Smaili

UBT International Conference

Load cells are essential components in modern measurement systems, widely utilized across various industries for precise force and weight measurements. This article presents the application of load cell technology in industry and in the testing field. In our project, an SC133 aluminum load cell with a highprecision weight sensor capable of measuring up to 20 kg was used. The load cell is mounted as a cantilever beam in a specially designed construction to ensure the testing of plastic bags and is connected through a microcontroller. The HX711 signal amplifier module was used, and data were monitored through an LCD screen …

Comparative Evaluation Of Microcontrollers For Real-Time Heart Rate Monitoring And Tachycardia/Bradycardia Detection, Arxhend Jetullahu, Luan Mulaku, Saranda Demolli

UBT International Conference

A surge in the yearning for portable gadgets related to healthcare has ignited a coupling of microchip controllers with models from the realm of machine learning, aimed at the task of immediate health observation. It's quite paramount, specifically in the context of identifying irregularities in heart rate, like tachycardia—where the heart races unusually fast—and bradycardia, an instance of a sluggish heartbeat. The neat thing is that this study takes a stab at contrasting the effectiveness among three popular microcontroller types—the ESP32, the Raspberry Pi, and the Arduino Nano 33 BLE Sense—in terms of real-time tracking of heartbeats and spotting any …

Using Object-Based Classification To Estimate Built-Up Density In An Urban Environment: A Case Study In Ferizaj, Kosova, Pajtim Zariqi, Lena Halounova

UBT International Conference

In this research, built-up density is quantified in Ferizaj’s urban setting through object-based classification on Planet Imagery (0.5m) acquired in 2019. The identification of homogeneous urban features is done by using ArcGIS Pro software and Mean Shift Segmentation. This segmentation is rather useful in the identification of clusters by incorporating the spatial and spectral characteristics that distinguish builtup and non-built-up regions. Training samples were obtained from satellite imagery and aerial images collected in 2019 with equal distribution of samples in the classification. Object-based classification has major benefits over pixel-based techniques in using spatial context and minimizing misclassification in urban areas. …

Fourier Transform Infrared Spectroscopic Characterization Of Raw And Thermally Treated Clays From Albania, Sidorela Vishkulli, Ilda Tole, Sonila Vito, Maria Hoxhaj, Ilirjana Boci

UBT International Conference

There is growing interest in using thermally treated clays as supplementary cementitious materials (SCMs) in construction. The suitability of the clays as SCMs varies according to their origin and composition. Clay minerals undergo several changes when heated, including dehydration, dehydroxylation, structural collapse, and new phases formation. This paper aims to evaluate the structural changes and modifications induced by thermal treatment of some selected clays from Albania. After grinding and sieving, the selected clays are treated thermally for one hour in different temperature values, ranging from 550 to 750°C. The raw and treated clays are analysed with FTIR spectrometer in order …

Expectations And Satisfaction Of Clients Who Collaborate With Architects For Interior Design, Ramadan Topuzi, Erblina Asani, Rrahim Sejdiu, Bujar Jashari, Agron Bajraktari

UBT International Conference

The study analyzes the needs, expectations and satisfaction of customers; considering the design skills of architects in the time of rapid technological developments and innovations, for the creation of an interior environment as attractive as possible. The study considers data from 230 respondents through questionnaires structured for this purpose, through purposive sampling as a non-probability sampling approach. The data were analyzed according to averages by grouping the respondents according to professions. The results show different levels of expectations regarding the time it takes to realize the design and the expected deadlines for the completion of the entire project. The design …

Comparison Between Concrete Column Retrofitting And Steel Jacketing, Blendi Ethemi, Asrim Rapuca

UBT International Conference

The project focuses on the strengthening of structural elements, specifically a column in a building being transformed from its current P+1 structure, used for residential purposes, into a new P+2 structure intended to serve as a bookstore and storage space. The analysis begins with the assessment of the current structure in two key aspects: the capacity of the existing column dimensions to accommodate new loads (ductility factor) and the verification of the concrete class through non-destructive testing. After completing the inspection of the current structure, two options are proposed for the central column of the building: concrete retrofitting by increasing …

Voltage Stability Analyses In Kosovo Power System, Kadri Kadriu, Armend Ymeri, Nexhmi Krasniqi

UBT International Conference

In recent years, there has been an increase in the frequency of blackouts in the system. On 21 June 2024 at 12:24 CET, due to a major incident in the Continental Europe power system region, a large part of the transmission systems of Albania, Montenegro, Bosnia and Herzegovina as well as Croatia suffered a voltage collapse followed by a total blackout. Research into preventing blackouts in power systems is crucial. Voltage stability analysis using the modal method is the focus of this paper, which is applied to the case study of the Kosovo power system. The voltage stability margin in …

Performance Analysis Of A 1 Mw Pv System Connected To The Distribution Grid, Armend Ymeri, Nexhmi Krasniqi, Kadri Kadriu, Alban Shala

UBT International Conference

This paper provides a thorough performance analysis of a 1 MW photovoltaic (PV) system integrated with the distribution network. The study evaluates the system's efficiency by examining the performance of both the PV modules and inverters. It presents detailed visualizations of the system, including peak power, the number of panels and inverters, panel orientation, tilt angles, and the spatial layout of the system in its deployment environment. Understanding these factors is crucial for assessing how the system will perform in its specific setting and for implementing necessary adjustments to enhance efficiency and electricity production. The paper highlights the impact of …