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Drinking Water Contaminants: Lead, Bruce I. Dvorak, Becky M. Schuerman Jun 2023

Drinking Water Contaminants: Lead, Bruce I. Dvorak, Becky M. Schuerman

Department of Civil and Environmental Engineering: Faculty Publications

Any lead exposure, even low levels, can be a serious health concern, especially for infants, children, and developing fetuses. This NebGuide discusses how to safely manage lead in a domestic water supply (or often referred to as a private well). This NebGuide includes discussion related to topics such as lead services lines and changes in public water supply regulations related to lead in drinking water.


Ocapo: Occupancy-Aware, Pdc Control For Open-Plan, Shared Workspaces, Anaradha Ravi, Archan Misra Jun 2023

Ocapo: Occupancy-Aware, Pdc Control For Open-Plan, Shared Workspaces, Anaradha Ravi, Archan Misra

Research Collection School Of Computing and Information Systems

Passive Displacement Cooling (PDC) has gained popularity as a means of significantly reducing building energy consumption overheads, especially in tropical climates. PDC eliminates the use of mechanical fans, instead using chilled-water heat exchangers to perform convective cooling. In this paper, we evaluate the impact of different parameters affecting occupant comfort in a 1000m2 open-floor area (consisting of multiple zones) of a ZEB (Zero Energy Building) deployed with PDC units and tackle the problem of setting the temperature setpoint of the PDC units to assure occupant thermal comfort. We tackle two key practical challenges: (a) the zone-level (i.e., occupant-experienced) temperature differs …


Multi-Physics Numerical Simulation Of Corrosion And Service Life Evaluation Of Novel Reinforced Concrete Systems, Jin Fan May 2023

Multi-Physics Numerical Simulation Of Corrosion And Service Life Evaluation Of Novel Reinforced Concrete Systems, Jin Fan

Dissertations

Durability challenges of reinforced concrete materials can shorten the service life and increase the carbon footprint of civil infrastructure systems. Novel alternative materials, such as high-performance fiber reinforced cementitious composites (HPFRCCs) and recycled aggregate concrete (RAC), offer an alternative to tradi-tional concrete materials by increasing the service life of infrastructure or reducing raw material consumption, thereby reducing the life-cycle carbon footprint. Due, in part, to a lack of robust numerical tools, predicting the durability response of these emerging cementitious materials has been insufficiently addressed. A time-dependent multi-physics modeling framework is proposed and adopted to investigate the chloride induced deterioration mechanisms …


Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian May 2023

Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian

Faculty Publications

Per- and polyfluorinated alkyl substances (PFAS) are an environmentally persistent group of chemicals that can pose an imminent threat to human health through groundwater and surface water contamination. In this review, we evaluate the subsurface behavior of a variety of PFAS chemicals with a focus on aqueous film forming foam (AFFF) discharge sites. AFFF is the primary PFAS contamination risk at sites such as airports and military bases due to use as a fire extinguisher. Understanding the fate and transport of PFAS in the subsurface environment is a multifaceted issue. This review focuses on the role of adsorbent, adsorbate, and …


Streambank Erosion Phenomena And Understanding: Current Research And Future Directions, Celso Castro-Bolinaga, Aaron R. Mittelstet, Kyle Mankin May 2023

Streambank Erosion Phenomena And Understanding: Current Research And Future Directions, Celso Castro-Bolinaga, Aaron R. Mittelstet, Kyle Mankin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Streams are in dynamic equilibrium with their environments, and as that environment is altered by human development and changing climate, streambank erosion is a common, but little understood, result. This article highlights the contributions of the special collection “Streambank Erosion, Sediment Dynamics, and Restoration (SER),” which assembled six studies that represent key advances in streambank erosion research, highlight current research in the field, and identify directions for future research. The studies in this special collection were grouped into three central themes: (1) streambank erosion monitoring, (2) streambank erodibility characterization, and (3) streambank erosion loading. In this article, key findings within …


Remote Sensing And Artificial Intelligence-Based Modeling And Prediction Of Harmful Algal Blooms In Lake Pontchartrain, Ian Smith May 2023

Remote Sensing And Artificial Intelligence-Based Modeling And Prediction Of Harmful Algal Blooms In Lake Pontchartrain, Ian Smith

LSU Master's Theses

Harmful Algal Blooms (HABs) and particularly toxic cyanobacterial harmful algal blooms (CyanoHABs) have become a growing threat to the environment, economy, communities, and human and animal health. This is particularly true for Lake Pontchartrain. Forecasting the occurrence of cyanobacterial HABs in Lake Pontchartrain is a process that currently does not exist, as nowcasting by the NCCOS Algal Bloom Monitoring System or the similar system implemented by the U.S. EPA is currently the only method to monitor HAB production in the Lake. This thesis made this process possible by identifying antecedent environmental conditions controlling CyanoHABs, describing the conditions using NASA satellite …


Exploring Machine Learning In Deep Foundation And Soil Classification Application, Mohammad Moontakim Shoaib May 2023

Exploring Machine Learning In Deep Foundation And Soil Classification Application, Mohammad Moontakim Shoaib

LSU Master's Theses

The applicability of several Machine Learning (ML) models was explored in this research to predict the ultimate capacity and load-settlement behavior of axially loaded single-driven piles from Cone Penetration Test (CPT) data. Additionally, a common CPT-based soil behavior type (SBT) classification system was reproduced using those ML models. Eighty static pile load tests and corresponding CPT data close to those pile locations were collected from 34 sites in Louisiana for the deep foundation application. On the other hand, 70 CPT soundings were taken in 14 different parishes across Louisiana for the soil classification application. Specifically, tree-based ML models such as …


Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo May 2023

Evaluation Of Temperature-Index And Energy-Balance Snow Models For Hydrological Applications In Operational Water Supply Forecasts, Tian Gan, David G. Tarboton, Tseganeh Z. Gichamo

Civil and Environmental Engineering Faculty Publications

In the western United States, snow accumulation, storage, and ablation affect seasonal runoff. Thus, the prediction of snowmelt is essential to improve the reliability of water supply forecasts to guide water allocation and operational decisions. The current method used at the Colorado Basin River Forecast Center (CBRFC) couples the SNOW-17 temperature index snow model and the Sacramento Soil Moisture Accounting (SAC-SMA) runoff model in a lumped approach. Limitations in parameter transferability and calibration requirements for changing conditions with the temperature-index model motivated this research, in which new avenues were investigated to assess and prototype the application of an energy-balance snow …


Columbus, Nebraska: Southern Housing Development Design Proposal, Ryan Weyers, Caiden Dynek, Alex Papa, Brexton Robertson, Kaden Perala May 2023

Columbus, Nebraska: Southern Housing Development Design Proposal, Ryan Weyers, Caiden Dynek, Alex Papa, Brexton Robertson, Kaden Perala

Honors Program: Senior Projects (Public)

The following paper proposes the design and creation of a new housing development in the city of Columbus, Nebraska in a lot to the south of the city and directly north of the Columbus wastewater treatment plant. The goal of this proposal is to provide readers with confidence that our company is the most qualified to complete the project and will create the safest, most comfortable, most efficient, and most cost-effective final design. This proposal seeks to offer a solution to the lack of affordable housing for the growing workforce in Columbus. In order to arrive at this solution, each …


Meta-Analysis Of Driving Behavior Studies And Assessment Of Factors Using Structural Equation Modeling, Duong Ngoc Hai, Chu Cong Minh, Nathan Huynh May 2023

Meta-Analysis Of Driving Behavior Studies And Assessment Of Factors Using Structural Equation Modeling, Duong Ngoc Hai, Chu Cong Minh, Nathan Huynh

Department of Civil and Environmental Engineering: Faculty Publications

The aim of this paper is to understand the factors that influence unsafe driving practices by examining published studies that utilized the Theory of Planned Behavior (TPB) to predict driving behavior. To this end, it reviews 42 studies published up to the end of 2021 to evaluate the predictive utility of TPB by employing a meta-analysis and structural equation model. The results indicate that these studies sought to predict 20 distinct driving behaviors (e.g., drink-driving, use of cellphone while driving, aggressive driving) using the original TPB constructs and 43 additional variables. The TPB model with the three original constructs is …


Lateral Swelling Pressure In Variably Saturated Expansive Clay, Steven Ray Garrett May 2023

Lateral Swelling Pressure In Variably Saturated Expansive Clay, Steven Ray Garrett

Theses and Dissertations

Lateral swelling pressure induced in expansive soils upon wetting can adversely impact the performance and integrity of earthen structures and foundations. The yearly cost associated with damage to structures from expansive clays in the United States is estimated to exceed the loss associated with natural disasters such as earthquakes, floods, and hurricanes. The main objective of this dissertation is to provide new insight into the evolution of lateral swelling pressure in variably saturated expensive soils under infiltration via physical testing. In the first part of this study, a new laboratory-scale testing apparatus was built to measure lateral and vertical swelling …


Research And Application Of Dynamic Compaction Treatment Method For Highway Subgrade In Karst Development Area, Liu Xiaoming, Wang Yigang, Zhao Minghua May 2023

Research And Application Of Dynamic Compaction Treatment Method For Highway Subgrade In Karst Development Area, Liu Xiaoming, Wang Yigang, Zhao Minghua

Journal of China & Foreign Highway

This paper utilizes discrete-continuum coupled numerical simulation to investigate the failure modes of karst cave roofs with varying spans under specific compaction energy levels. The relationship between the span of the cave roof and the compaction energy required to cause roof collapse is established, providing an estimation method for the maximum unsupported span of cave roofs within the subgrade area. Based on this, the stability of karst cave foundations under the influence of subgrade loads can be evaluated. Depending on the results, a double-layer reinforced continuous concrete slab can be installed in the pavement base to enhance stability and mitigate …


Comparative Analysis Of Asphalt Pavement Performance Prediction Models Based On Gamma And Markov Processes, Ma Shibin, Chen Yonghao May 2023

Comparative Analysis Of Asphalt Pavement Performance Prediction Models Based On Gamma And Markov Processes, Ma Shibin, Chen Yonghao

Journal of China & Foreign Highway

Pavement performance prediction is a critical component of pavement management systems, serving as an essential basis and prerequisite for decision-making in asphalt pavement maintenance. This paper introduces the relevant theories of Gamma and Markov stochastic processes to construct asphalt pavement performance prediction models and address uncertainties related to pavement degradation. The results show that stochastic process models are effective in predicting pavement performance degradation and service life. Matlab programming was used to predict asphalt pavement performance and lifespan, yielding pavement degradation curves that significantly improve prediction accuracy and reliability. Finally, taking a test road section in Hebei Province as an …


Study On Interlayer Bonding Properties And Influence Factors Of Cape Seal, Li Yan, Zhang Chengxue, Qiu Yeji, Zhang Haijun May 2023

Study On Interlayer Bonding Properties And Influence Factors Of Cape Seal, Li Yan, Zhang Chengxue, Qiu Yeji, Zhang Haijun

Journal of China & Foreign Highway

To address pavement issues such as shoving and rutting caused by insufficient bonding strength in cape seal layers, this paper investigates the interlayer bonding properties and influencing factors of cape seal. Mechanical tests were conducted using a pavement interlayer shear-pull testing device. Through interlayer pull-off, direct shear, and torsional shear tests, the maximum tensile force, shear force, and torque at failure were obtained. The interlayer bonding performance of cape seal was analyzed in terms of gravel coverage rates, as well as upper and lower layer combinations. The results show that when the gravel coverage rate is 80%-90%, and the cape …


Fracture Mechanics‐Based Fatigue Study Of Corrugated Steel Webs, Li Haidi, Yang Lei May 2023

Fracture Mechanics‐Based Fatigue Study Of Corrugated Steel Webs, Li Haidi, Yang Lei

Journal of China & Foreign Highway

To develop fatigue analysis and evaluation methods for corrugated steel web structures, constant-amplitude fatigue load tests were conducted on experimental beam models, supplemented by fatigue test data from domestic and international studies. The finite element submodeling method was employed to obtain stress distribution functions at structural details, and the weight function method was used to derive the stress intensity factor at the crack tip. The Paris law in fracture mechanics was applied to derive the S-N curve for corrugated steel web structures. Comparative analysis with fatigue test results shows that when the initial crack depth is set as a0=t/20 (accounting …


Research On Multi‐Source And Heterogeneous Data Integration Of Large Bridge Health Monitoring System, Wang Daijun, Zhou Tiantu, Fu Junmin, Chen Xing, Lu Shuai, Yu Zheng May 2023

Research On Multi‐Source And Heterogeneous Data Integration Of Large Bridge Health Monitoring System, Wang Daijun, Zhou Tiantu, Fu Junmin, Chen Xing, Lu Shuai, Yu Zheng

Journal of China & Foreign Highway

Large bridge health monitoring systems are characterized by numerous sensors, diverse types, various communication methods, and flexible network configurations. The multi-source heterogeneous nature of the data poses significant challenges for data integration. To address the application requirements of bridge health monitoring, this paper designs a multi-source heterogeneous data integration scheme. The scheme achieves structured storage of multi-source heterogeneous data and introduces the concept of “structured communication.” This enables structured communication configuration, unified communication control, and flexible data processing, standardizing and simplifying communication configuration management in data acquisition systems. These improvements enhance code simplicity, maintainability, and the overall integration level of …


Selection And Design Of Anchorage For Suspension Bridge In Downhill Area Under Complex Geological Conditions, Chen Yongliang, He Shiyong, Xia Zhixian, Wu Wenxiang May 2023

Selection And Design Of Anchorage For Suspension Bridge In Downhill Area Under Complex Geological Conditions, Chen Yongliang, He Shiyong, Xia Zhixian, Wu Wenxiang

Journal of China & Foreign Highway

Due to the complexities of design and construction, long-span single-tower suspension bridges are rarely applied in practice. The main bridge of the Jinsha River Bridge at Tiger Leaping Gorge adopts a 766 m single-span single-tower steel truss suspension bridge. On the Lijiang anchorage side, complex geological conditions posed significant challenges due to geological structures, while the reservoir level of the planned hydropower station created adverse hydrological conditions for waterproofing and durability of the anchorage system. The selection of an appropriate anchorage type was therefore particularly challenging. This paper first details the selection process for anchorage under complex geological conditions. It …


Study On Countermeasures And Genetic Analysis Of Sloping Bridge Pile Hole Wall Failure, Yang Hua, Yin Xiaotao May 2023

Study On Countermeasures And Genetic Analysis Of Sloping Bridge Pile Hole Wall Failure, Yang Hua, Yin Xiaotao

Journal of China & Foreign Highway

The stability of slopes and the safety of bridge piles are interdependent, and ensuring the safety of sloping terrain is crucial for the safe construction of bridge piles. Based on three collapsed pile sections of the Huadizhai No. 2 Bridge, this paper utilized geological surveys to design initial terrain and altered terrain slope stability calculation conditions, along with horizontal compensation force calculation conditions under a safety standard of 1.35. By integrating geological analysis, slope stability assessment, and compensation force evaluations, the causes of pile hole collapse and corresponding countermeasures were analyzed. The results show that under the initial terrain, the …


Research On Gas Migration And Ventilation Disaster Prevention In Highway Tunnel, Wang Zhongqi, Lin Zhi, Feng Sen, Yang Hongyun, Chen Xiang, Liu Jiang May 2023

Research On Gas Migration And Ventilation Disaster Prevention In Highway Tunnel, Wang Zhongqi, Lin Zhi, Feng Sen, Yang Hongyun, Chen Xiang, Liu Jiang

Journal of China & Foreign Highway

To understand the gas migration patterns and ventilation disaster prevention techniques during tunnel construction, this paper uses a real tunnel as the engineering context. A 3D transient ventilation physical model was established using Ansys Fluent, and the effects of ventilation on gas concentration were analyzed in combination with on-site monitoring data. The results show that the uneven diffusion of gas and airflow is prominent. Gas concentration and wind speed stabilize at a distance of 120 m from the tunnel face as ventilation time increases. During gas monitoring and prevention, special attention should be paid to the area between the tunnel …


Research On Influence Factors And Efficiency Analysis Of Expressway Maintenance Marketization, Zhong Wen, He Shoukui, Wang Xiaodong May 2023

Research On Influence Factors And Efficiency Analysis Of Expressway Maintenance Marketization, Zhong Wen, He Shoukui, Wang Xiaodong

Journal of China & Foreign Highway

To promote market-oriented reform of highway maintenance, this paper investigates its influencing factors and outcomes and proposes an evaluation model for assessing its effects. A panoramic analysis method within a three-dimensional framework was employed to determine the evaluation content. Drawing on the balanced scorecard concept, the analysis incorporates four dimensions: business, user, internal management, and learning and growth, with the innovative addition of a social responsibility dimension to construct an evaluation indicator system. Subsequently, a cloud-based extension model was developed to evaluate the effectiveness of expressway maintenance marketization and calculate the evaluation grade. Empirical analysis was conducted using data from …


Study On The Minimum Radius Of Vertical Curve Of Highway Main Line Entrance Section Based On Merging Sight Distance, Li Yang, Zhao Yemei, Chen Tianxing May 2023

Study On The Minimum Radius Of Vertical Curve Of Highway Main Line Entrance Section Based On Merging Sight Distance, Li Yang, Zhao Yemei, Chen Tianxing

Journal of China & Foreign Highway

Given the limited research on the vertical curve radius of highway mainline entrance sections and the lack of differentiation between entrance and exit sections in existing studies, this paper identifies merging sight distance as the primary influencing factor for the vertical curve radius of entrance sections. Using merging sight distance as the control condition, the vertical curve radius of entrance sections was studied. A safety merging sight distance calculation model for highway mainline entrance sections was established by analyzing the traffic behavior characteristics of vehicles on the entrance mainline and considering drivers’ psychological and physiological characteristics. The sight distance model …


Inspection And Evaluation Of Load‐Bearing Capacity Of Hollow‐Box Arch Bridge, Song Zegang, Yang Min May 2023

Inspection And Evaluation Of Load‐Bearing Capacity Of Hollow‐Box Arch Bridge, Song Zegang, Yang Min

Journal of China & Foreign Highway

The inspection and evaluation of the load-bearing capacity of in-service bridges are crucial for ensuring structural and operational safety. This paper investigates a 90 m span hollow-box arch bridge, assessing its damage condition, material properties, and state parameters to determine partial evaluation coefficients. The bridge’s ultimate limit state and serviceability limit state load-bearing capacities of the main arch ring were then evaluated using both the original design standards and the current code. The results show that, compared to the original design standards, the safety factor for the compressive load-bearing capacity of the main arch ring cross-section is significantly reduced when …


Application Research And Prospect Of Passive Battered Pile, Zhou Dequan, Wang Chuangye, Zhou Yi, Zhao Yadang May 2023

Application Research And Prospect Of Passive Battered Pile, Zhou Dequan, Wang Chuangye, Zhou Yi, Zhao Yadang

Journal of China & Foreign Highway

Battered piles oriented in specific directions demonstrate superior horizontal load-bearing capacity compared to vertical piles. However, the working mechanism of battered piles remains inadequately understood, and corresponding design standards are yet to be established. These limitations hinder the effective utilization and application of the horizontal load-bearing and stability potential of battered piles. This paper comprehensively analyzes the soil-pile interaction mechanisms, horizontal displacement, and load-bearing behavior of passive battered piles and their composite systems under lateral unloading and lateral loading conditions, using model tests, numerical simulations, and theoretical analysis. In addition, it proposes future research directions aimed at advancing the study …


Study On Applicability Of Flexible Gabion Revetment In Soft Soil Subgrade In Lake District, Su Weiwei, Lei Mingxuan, Liu Guotian, Zhang Liujun, Liu Junyong May 2023

Study On Applicability Of Flexible Gabion Revetment In Soft Soil Subgrade In Lake District, Su Weiwei, Lei Mingxuan, Liu Guotian, Zhang Liujun, Liu Junyong

Journal of China & Foreign Highway

Based on FLAC3D finite difference software, this paper conducts numerical simulations of both flexible gabion revetment structures and rigid revetment structures to compare their deformation and stress characteristics. The results indicate that the flexible gabion revetment structure demonstrates excellent applicability for soft soil subgrades in lake districts. Compared with rigid revetment structures, the gabion revetment structure improves overturning stability through coordinated deformation within the foundation. It significantly reduces the basal stress, thus lowering the bearing capacity requirements for the foundation, and ensures a more uniform stress distribution at the base, minimizing differential settlement and enhancing foundation stability. Moreover, the gabion …


Study On Supporting Effect Of Pre‐Stressed Rock Bolts On Tunnel Face, Shen Xiangqian, Chen Daoyun, Zheng Chao May 2023

Study On Supporting Effect Of Pre‐Stressed Rock Bolts On Tunnel Face, Shen Xiangqian, Chen Daoyun, Zheng Chao

Journal of China & Foreign Highway

Focusing on the stability issues of the tunnel face in the large deformation section of soft rock in the Muzhailing Tunnel on the Weiyuan-Wudu Expressway, this paper proposes a technical solution for temporary reinforcement of the tunnel face using pre-stressed rock bolts. Numerical simulations were conducted to evaluate the reinforcement effect and effective range of pre-stressed rock bolts on the tunnel face, and the influence of initial ground stress on the reinforcement effect was further analyzed. The results show that under the given engineering conditions, pre-stressed rock bolts demonstrate significantly better reinforcement effects on the tunnel face compared to fully …


Study On Health State Evaluation Method Of Highway Tunnel Based On Neutrosophic Theory, Deng Fayou, Xia Caichu, Xu Chongbang May 2023

Study On Health State Evaluation Method Of Highway Tunnel Based On Neutrosophic Theory, Deng Fayou, Xia Caichu, Xu Chongbang

Journal of China & Foreign Highway

The structural complexity and inherent uncertainties of highway tunnels necessitate comprehensive consideration of various uncertain factors to reasonably evaluate their health state. By introducing neutrosophic theory, which accounts for structural uncertainties, this paper proposes a health state evaluation method for highway tunnels based on neutrosophic cosine and tangent similarity measures. The proposed method was applied to evaluate the health state of 10 samples. A comparison between the actual evaluation grades and the results obtained using the proposed method shows that the evaluation results are consistent with the actual grades. This indicates that the proposed method effectively addresses uncertainties in the …


Interlayer Bonding Performance Of Wtr/Apao Composite Modified Asphalt, Ji Hongyan, Yan Kezhen, Yuan Jian, Zhang Xuanyu May 2023

Interlayer Bonding Performance Of Wtr/Apao Composite Modified Asphalt, Ji Hongyan, Yan Kezhen, Yuan Jian, Zhang Xuanyu

Journal of China & Foreign Highway

To investigate the bonding performance of waste tire rubber (WTR)/ amorphous α-olefin copolymer (APAO) composite modified asphalt as a waterproof bonding layer in asphalt pavements on cement concrete bridges, shear and pull-off tests were conducted. The shear strength and pull-off strength of SBS-modified asphalt, WTR-modified asphalt, and WTR/APAO composite modified asphalt were compared under different application rates and temperatures. The results show that WTR/APAO composite modified asphalt exhibits the best bonding performance, followed by WTR-modified asphalt, with SBS-modified asphalt performing the worst. Based on the shear and pull-off strengths at different temperatures, the optimal application rates were determined as 1.7 …


Optimization Study On Indoor Vibratory Compaction Curves Of Cement Stabilized Macadam, Qiu Youqiang, Zhang Liujun May 2023

Optimization Study On Indoor Vibratory Compaction Curves Of Cement Stabilized Macadam, Qiu Youqiang, Zhang Liujun

Journal of China & Foreign Highway

To obtain well-defined secondary convex vibratory compaction curves and reduce the need for supplemental compaction point tests, this paper uses vibratory compaction tests for cement stabilized macadam in laboratory settings. Tests were conducted for two pavement sections along National Highway 110 (Hohhot to Bikeqi), exploring the influence of predefined moisture content intervals on vibratory compaction curves under varying cement dosages. The vibratory compaction curves were also compared with heavy compaction curves for analysis. The results show that the vibratory compaction curve is significantly influenced by the predefined moisture content intervals and cement dosage. For a moisture content interval of 1%, …


Study On Treatment Of Karst Foundation By Dynamic Compaction, Lyu Jiang, Zhao Hui, Yang Biao May 2023

Study On Treatment Of Karst Foundation By Dynamic Compaction, Lyu Jiang, Zhao Hui, Yang Biao

Journal of China & Foreign Highway

Dynamic compaction is a commonly used method for treating karst foundations with cavities; however, the design parameters of dynamic compaction under different working conditions lack clear standards. This paper employs the finite element software Abaqus to simulate the effects of surrounding rock quality and karst roof thickness on the stability of karst cave roofs during dynamic compaction treatment. The results indicate that the vertical displacement and maximum tensile stress of karst cave roofs are negatively correlated with roof thickness. For Grade II and III surrounding rocks with better properties, no cave collapse occurred after dynamic compaction treatment. In contrast, for …


Research On Road Crack Recognition Model Based On Yolo V3 Deep Learning Algorithm, Su Weiguo, Wang Jingxiao May 2023

Research On Road Crack Recognition Model Based On Yolo V3 Deep Learning Algorithm, Su Weiguo, Wang Jingxiao

Journal of China & Foreign Highway

To address the challenges of manual intervention in road crack detection and the inaccuracy of traditional recognition algorithms, this paper proposes a road crack recognition method based on the YOLO v3 deep learning algorithm. The dataset images were first resized to 416×416 pixels. Labelme was then used to annotate cracks in the images and convert the boundary box location information. Finally, the YOLO v3 algorithm framework was employed for model training. The results show that the YOLO v3 algorithm achieves precision, recall, and F1 scores above 95%, with an image detection speed of 0.123 seconds per image. The YOLO v3 …