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2024

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Articles 181 - 210 of 9148

Full-Text Articles in Engineering

Tensile Strain Validation Of Welded Wire Reinforcement, Alvaro Montes Dec 2024

Tensile Strain Validation Of Welded Wire Reinforcement, Alvaro Montes

Theses and Dissertations

There have been historical concerns regarding the ductility of welded wire reinforcement (WWR). Recent changes in ACI 318-19 now require all grades of A615 and Grade 100 A706 nonprestressed steel reinforcement to have a ratio of tensile strength to yield strength greater than 1.10 and 1.17 respectively. Although this code requirement does not currently apply to WWR, this preemptive study investigated the current state of the art of WWR manufactured in North America in preparation for such a possibility. This project included the tensile-testing of approximately 365 WWR material specimens of various cross-sectional sizes to determine the ratio of tensile-to-yield …


Post-Processing National Water Model Long-Range Forecasts With Random Forest Regression In The Cloud To Improve Forecast Accuracy For Decision-Makers And Water Managers, Jacob Matthew Anderson Dec 2024

Post-Processing National Water Model Long-Range Forecasts With Random Forest Regression In The Cloud To Improve Forecast Accuracy For Decision-Makers And Water Managers, Jacob Matthew Anderson

Theses and Dissertations

Post-processing bias correction of streamflow forecasts can be useful in the hydrologic modeling workflow to fine-tune forecasts for operations, water management, and decision-making. Hydrologic model runoff simulations include errors, uncertainties, and biases, leading to less accuracy and precision for applications in real-world scenarios. We used random forest regression to correct biases and errors in streamflow predictions from the U.S. National Water Model (NWM) long-range streamflow forecasts, considering U.S. Geological Survey (USGS) gauge station measurements as a proxy for true streamflow. We used other features in model training, including watershed characteristics, time fraction of year, and lagged streamflow values, to help …


Local Food System Planning On Multiple Governance Scales: A Grounded Theory Analysis, Decker Ure Dec 2024

Local Food System Planning On Multiple Governance Scales: A Grounded Theory Analysis, Decker Ure

Theses and Dissertations

Local food systems (LFS) comprise the people, policies, infrastructure and practices of food production, distribution, and consumption in localized areas. LFS are becoming an increasingly important part of urban sustainable development and have recently gained significant traction in the urban planning and sustainable community spheres. Worldwide shocks to global food systems such as the COVID-19 pandemic and the Ukraine-Russia war have further elevated global interest in LFS, bringing local food to the forefront of many communities as they try to insulate themselves and their food supply from future risk. However, despite this growing interest in and policy momentum for local …


Harnessing Extrinsic Dissipation To Enhance The Toughness Of Composites And Composite Joints: A State-Of-The-Art Review Of Recent Advances, Gilles Lubineau, Marco Alfano, Ran Tao, Ahmed Wagih, Arief Yudhanto, Xiaole Li, Khaled Almuhammadi, Mjed Hashem, Ping Hu, Hassan A. Mahmoud, Fatih Oz Dec 2024

Harnessing Extrinsic Dissipation To Enhance The Toughness Of Composites And Composite Joints: A State-Of-The-Art Review Of Recent Advances, Gilles Lubineau, Marco Alfano, Ran Tao, Ahmed Wagih, Arief Yudhanto, Xiaole Li, Khaled Almuhammadi, Mjed Hashem, Ping Hu, Hassan A. Mahmoud, Fatih Oz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Interfaces play a critical role in modern structures, where integrating multiple materials and components is essential to achieve specific functions. Enhancing the mechanical performance of these interfaces, particularly their resistance to delamination, is essential to enable extremely lightweight designs and improve energy efficiency. Improving toughness (or increasing energy dissipation during delamination) has traditionally involved modifying materials to navigate the well-known strength-toughness trade-off. However, a more effective strategy involves promoting non-local or extrinsic energy dissipation. This approach encompasses complex degradation phenomena that extend beyond the crack tip, such as long-range bridging, crack fragmentation, and ligament formation. This work explores this innovative …


Balancing Sustainability Goals And Treatment Efficacy For Pfas Removal From Water, Md Moshiur Rahman Tushar, Zaki Alam Pushan, Nirupam Aich, Stetson Rowles Dec 2024

Balancing Sustainability Goals And Treatment Efficacy For Pfas Removal From Water, Md Moshiur Rahman Tushar, Zaki Alam Pushan, Nirupam Aich, Stetson Rowles

Civil Engineering & Construction: Faculty Publications

Per- and polyfluoroalkyl substances (PFAS) are emerging water contaminants with significant environmental and health impacts, posing challenges in water treatment due to their high stability and persistence. With increasing regulations, a critical need remains in understanding the sustainability of PFAS treatment technologies. Our review examines the environmental, economic, and social impacts of current PFAS treatment technologies across different water types and contexts. Additionally, we propose a framework for future sustainability studies to enable more holistic technology evaluations under specific conditions.


The Coalition Development Of Allied Close Air Support Doctrine During World War Ii, David S. Stieghan Dec 2024

The Coalition Development Of Allied Close Air Support Doctrine During World War Ii, David S. Stieghan

Doctoral Dissertations and Projects

This research aims to discover how the American and British air forces worked collaboratively to provide ground support to their armies in Europe during World War II. While the official histories and scholars of the two countries concentrate on their unique national efforts, they analyze little of their cooperative efforts. By examining primary and secondary research sources to discover the experiments, doctrine development, and combat experience of both air forces, an understanding emerges that both nations combined their efforts in World War II in separate directions until beginning to work together on planning for the D-Day invasion.

By discovering the …


Kinetic Modeling Of Bacteria Removal From Suspensions By Magnetic Nanoparticle Capture And Magnetic Separation, Bowen J. Houser Dec 2024

Kinetic Modeling Of Bacteria Removal From Suspensions By Magnetic Nanoparticle Capture And Magnetic Separation, Bowen J. Houser

Theses and Dissertations

This thesis investigates the kinetic modeling of bacteria removal from suspensions using magnetic nanoparticle (MNP) capture and magnetic separation. Functionalized magnetic nanoparticles, especially those coated with polydopamine (pDA), were employed to bind with various bacterial species in phosphate-buffered saline (PBS), apple juice, whole blood, and its components. By analyzing the capture efficiency and kinetics of capture across different bacterial species and mediums, we developed mathematical models describing the capture kinetics of bacteria by the pDA-MNPs. Experimental results demonstrated that pDA-coated MNPs achieved high capture efficiency with certain Gram-positive species like Staphylococcus aureus, and one Gram-negative species, Neisseria perflava; however, capture …


A Computational And Mathematical Approach To The Preclinical Development Of Alpha Emitting Radiopharmaceutical Therapies, Abdulaziz Said Dec 2024

A Computational And Mathematical Approach To The Preclinical Development Of Alpha Emitting Radiopharmaceutical Therapies, Abdulaziz Said

McKelvey School of Engineering Graduate Student Theses & Dissertations

Numerous candidate nuclides have been undergoing rigorous preclinical development in the pursuit of novel targeted therapies. Successful development of these drugs relies on the understanding of physiological impacts at the macro and micro scales, in addition to a scalable process for their production. Here, mathematical and computerized approaches have been developed to guide this preclinical development. In this report, two alpha emitting nuclides Pb-212 and Ra-223 are modeled. Radium-223 dichloride citrate a newly approved ion indicated for treatment of bone metastatic castrate resistant prostate cancer, irradiates lesions through targeted uptake in bone at sites of disease. We have undertaken the …


Safety And Optimality Monitors For Learning-Enabled Systems Using Conformal Prediction, Jackson Cox Dec 2024

Safety And Optimality Monitors For Learning-Enabled Systems Using Conformal Prediction, Jackson Cox

McKelvey School of Engineering Graduate Student Theses & Dissertations

The use of machine learning to create data-driven plant models and controllers has led to an increased need for safety and optimality monitors for model-based systems. System plant models are subject to uncertainty due to learning constraints such as unseen data and overfitting or physical constraints such as unknown dynamics and noise. This uncertainty is detrimental to safety-critical systems and must be properly regulated. To curb this uncertainty, we create prediction sets using the guarantees provided by Conformal Prediction. With a user-specified high probability, these prediction sets contain the true plant system states for an entire prediction horizon, which we …


Pyrophosphate-Free Glycolysis In Clostridium Thermocellum Increases Both Thermodynamic Driving Force And Ethanol Titers, Bishal Dev Sharma, Shuen Hon, Eashant Thusoo, David M. Stevenson, Daniel Amador-Noguez, Adam M. Guss, Lee R. Lynd, Daniel G. Olson Dec 2024

Pyrophosphate-Free Glycolysis In Clostridium Thermocellum Increases Both Thermodynamic Driving Force And Ethanol Titers, Bishal Dev Sharma, Shuen Hon, Eashant Thusoo, David M. Stevenson, Daniel Amador-Noguez, Adam M. Guss, Lee R. Lynd, Daniel G. Olson

Dartmouth Scholarship

Background

Clostridium thermocellum is a promising candidate for production of cellulosic biofuels, however, its final product titer is too low for commercial application, and this may be due to thermodynamic limitations in glycolysis. Previous studies in this organism have revealed a metabolic bottleneck at the phosphofructokinase (PFK) reaction in glycolysis. In the wild-type organism, this reaction uses pyrophosphate (PPi) as an energy cofactor, which is thermodynamically less favorable compared to reactions that use ATP as a cofactor. Previously we showed that replacing the PPi-linked PFK reaction with an ATP-linked reaction increased the thermodynamic driving force of glycolysis, but only had …


Beyond The Surface: Understanding Temperature Polarisation In Dcmd Membranes Through Varied Operational Parameters, Hiras Ahamed Hijaz, Masoumeh Zargar, Abdellah Shafieian, Amir Razmjou, Mehdi Khiadani Dec 2024

Beyond The Surface: Understanding Temperature Polarisation In Dcmd Membranes Through Varied Operational Parameters, Hiras Ahamed Hijaz, Masoumeh Zargar, Abdellah Shafieian, Amir Razmjou, Mehdi Khiadani

Research outputs 2022 to 2026

Conventionally, a single Temperature Polarisation Coefficient (TPC) value is calculated to quantify Temperature Polarisation (TP). In this research, the extent of polarisation is investigated by capturing temperature profiles at specific points along a MD membrane using miniature thermocouples, eliminating the need for TPC calculations. The extent of polarisation at a point is affected by two contributory factors, namely the proximity of flow inlets and the difference in vapour pressure across the membrane at that point. Under this direction, this work examined the influence of permeate temperature, feed salinity, and flow direction on the development of the temperature profiles. Our analysis …


Kinetics Model Of Cananga (Cananga Odorata) Fresh Flower Extraction Using Microwave Hydrodistillation Method, Darnengsih Darnengsih, Hikmatun Ni’Mah, Mahfud Mahfud, Ayu Chandra Kartika Fitri Dec 2024

Kinetics Model Of Cananga (Cananga Odorata) Fresh Flower Extraction Using Microwave Hydrodistillation Method, Darnengsih Darnengsih, Hikmatun Ni’Mah, Mahfud Mahfud, Ayu Chandra Kartika Fitri

Makara Journal of Science

Recent studies have focused on improving essential oil extraction methods by incorporating advanced technologies, such as microwave-assisted hydrodistillation (MHD). Despite these advancements, further research is necessary to fully understand how different kinetic models influence extraction efficiency. This study evaluates several kinetic models for extracting essential oil from fresh Cananga flowers using MHD, examining how varying microwave power affects extraction rates and correlates with kinetic model parameters. The extraction process involved introducing 200 grams of fresh Cananga flowers in 400 mL of distilled water and subjecting the mixture to microwave power levels of 200 W, 400 W, and 600 W. The …


Optimization Of Construction Scheme Of Ultra‑Large Special‑Shaped Foundation Pit Adjacent To Existing Station And Temporary Steel Bridge, Chen Dengwei Dec 2024

Optimization Of Construction Scheme Of Ultra‑Large Special‑Shaped Foundation Pit Adjacent To Existing Station And Temporary Steel Bridge, Chen Dengwei

Journal of China & Foreign Highway

With the intensifying development density of urban underground space in China,the impact of ultra-large foundation pit construction on the normal operation of adjacent structures cannot be ignored.Relying on the Huangmugang Comprehensive Transportation Hub Project in Shenzhen,this paper studied the deformation of the envelope structure and soil caused by the excavation of the ultra-large special-shaped foundation pit,as well as the structural response of the deformation of the adjacent existing station and the temporary steel bridge.The paper optimized the construction scheme of the special-shaped foundation pit excavation.The results show that the deformation trend of the envelope structure on the north and south …


Friction‑ 1d Transformer : A 1d Vision Transformer Hybrid Model For Skid Resistance Prediction On Asphalt Pavements, Pei Feifei, Nie Zilong, Xu G Uomin, Zhan You, Gong Xianqi, Ai Changfa, Deng Yuan, Ji Zhengyun, Wang Shifa Dec 2024

Friction‑ 1d Transformer : A 1d Vision Transformer Hybrid Model For Skid Resistance Prediction On Asphalt Pavements, Pei Feifei, Nie Zilong, Xu G Uomin, Zhan You, Gong Xianqi, Ai Changfa, Deng Yuan, Ji Zhengyun, Wang Shifa

Journal of China & Foreign Highway

The friction performance of road surfaces is an important indicator of highway safety,which is closely related to road texture.In this paper,a set of three-dimensional denoising methods for road texture data with different noise levels was proposed,which could effectively remove noise while preserving local texture features.In addition,a skid resistance prediction model named Friction- 1D Transformer was developed based on the design concept of Vision Transformer (VIT) for skid resistance evaluation of asphalt pavements.Unlike traditional convolutional neural networks,the Friction- 1D Transformer utilized positional encoding structures and multi-head attention mechanisms to extract global features from one-dimensional (1D) texture signals along the direction of …


Phosphorus Adsorption Capacity Of Volcanic Scoria, Easton Jeffrey Perkins Dec 2024

Phosphorus Adsorption Capacity Of Volcanic Scoria, Easton Jeffrey Perkins

Theses and Dissertations

Phosphorus (P) pollution in stormwater runoff poses a significant threat to water quality, contributing to eutrophication and ecosystem degradation. This research evaluates the potential of volcanic scoria (VSco), an abundant and cost-effective resource in Utah, USA, to influence P concentrations in urban stormwater systems. Batch adsorption experiments examined the behavior of VSco across three particle sizes—fine (<0.841 mm), medium (0.841–2 mm), and granular (2.38–9.5 mm)—under conditions mimicking stormwater scenarios. The results reveal that fine VSco exhibited higher adsorption efficiency than medium and granular sizes, achieving notable P removal at higher concentrations. However, at lower concentrations, fine VSco showed potential for P release due to desorption of pre-existing P. Medium and granular VSco showed minimal adsorption capacity and, in some cases, acted as P sources, highlighting a dual potential depending on stormwater conditions. Adsorption isotherms indicate that the adsorption behavior of fine VSco aligns with the Langmuir model, with a finite and relatively low adsorption capacity. Calculated distribution coefficient (Kd) values for fine VSco ranged from 0.04 to 0.005 L/g, indicating weak adsorption efficiency compared to materials like activated carbon (1–10 L/g) or soils with moderate adsorption capacity (0.1–0.5 L/g). Loss-on-ignition tests confirmed that VSco’s performance is driven by its physical and chemical properties, particularly its calcium content, rather than organic matter. The study emphasizes caution in applying fine VSco for stormwater remediation due to its potential to release P under typical runoff conditions. However, fine VSco may still be viable in specific scenarios where P levels are higher, such as in stormwater hotspots or localized areas with elevated concentrations, allowing for targeted remediation. The research underscores the need for further testing to refine VSco’s applications, particularly in low-impact development (LID) practices, such as infiltration basins and rain gardens, to effectively manage P levels while supporting ecological and aesthetic goals. These findings contribute to understanding the complex role of VSco in urban stormwater systems, offering insights for sustainable water quality management and nutrient cycling in urban landscapes.


Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas Dec 2024

Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas

Theses and Dissertations

The presence of a non-liquefied crust overlying a liquefied layer has been found to have a significant effect on sand ejecta and surficial liquefaction damage, as observed by Ishihara (1985). Following the 2010-2011 Canterbury seismic sequence in New Zealand, almost no foundation deformation occurred in areas with liquefaction susceptible soils overlain by at least a 3 meter thick crust [1]. In contrast, the 2012 Emilia-Romagna earthquake in Italy provided surface evidence of liquefaction despite 6+ meter thick crusts. Several researchers have proposed liquefaction prediction models [e.g. LPI [2], Ishihara Curves [3], LSN [4], LPIISH [5] and the methods proposed by …


Experimental Investigation On Shrinkage Effect Of Ultra‑High Performance Concrete Under Steam Curing, Li Bing, Yang Tengyu, Fang Changle, Luo Zirun, Li Chuanxi, Tan Ke Dec 2024

Experimental Investigation On Shrinkage Effect Of Ultra‑High Performance Concrete Under Steam Curing, Li Bing, Yang Tengyu, Fang Changle, Luo Zirun, Li Chuanxi, Tan Ke

Journal of China & Foreign Highway

Determining the free shrinkage of U HPC is an important basis for analyzing the shrinkage effect of steel UHPC composite bridge deck.Therefore,based on the UHPC materials to be used in a project,three batches of UHPC free shrinkage specimens were made,and three specimens were made in each batch.By testing the strain and temperature of specimens during curing,the free shrinkage strain-age curve and temperature-age curve of UHPC were obtained.The development and variation law of UHPC shrinkage strain are discussed.Based on the experimental results,the equivalent time is introduced on the basis of Arrhenius empirical formula,and a modified model of free shrinkage is proposed.Finally,based …


Mechanical And Vegetative Performance Of Bamboo Fiber‑Reinforced Eco‑Concrete With Recycled Aggregate, Li Tao, Deng Bofan, He Maolin, Liu Ting, Chen Houde Dec 2024

Mechanical And Vegetative Performance Of Bamboo Fiber‑Reinforced Eco‑Concrete With Recycled Aggregate, Li Tao, Deng Bofan, He Maolin, Liu Ting, Chen Houde

Journal of China & Foreign Highway

In response to the current common urban construction waste disposal issue,this study utilized processed recycled construction waste aggregate and bamboo waste materials to produce bamboo fiber-reinforced eco-concrete with recycled aggregate.By adjusting the dosage of bamboo fiber,the effects of the dosage of bamboo fiber on the mechanical and vegetative performance of the concrete were systematically analyzed by means of orthogonal tests and verification methods.The test results indicate that bamboo fiber enhances the toughness of eco-concrete significantly.Particularly,when the dosage of bamboo fiber exceeds 3.0 kg/m3,there is a significant enhancement in the tensile performance of the eco-concrete with recycled aggregate.Due to the spatial …


Curing Law And Road Performance Of Polyurethane Mixture, Sun Shengkai, Zheng Mao, Tang Xiong, Liu Li, Zhong Shengran, Si Te Dec 2024

Curing Law And Road Performance Of Polyurethane Mixture, Sun Shengkai, Zheng Mao, Tang Xiong, Liu Li, Zhong Shengran, Si Te

Journal of China & Foreign Highway

Polyurethane mixture is composed of polyurethane binder,rubber particles,and stones.Compared with ordinary asphalt mixture,it has the characteristics of a higher content of rubber particles and large void ratios.This article first tested the viscosity-time curve and viscosity-temperature curve of one-component polyurethane and determined the compaction temperature of the polyurethane mixture.Based on the rutting test,three-point bending test,water immersion Marshall test,freeze-thaw splitting test,and pendulum friction test,the road performance of the polyurethane mixture under different replacement amounts of rubber particles was tested.The research results show that the mixing temperature of PU- 1 polyurethane mixture can be basically controlled between 73 ℃ and 81 ℃,and it …


Elimination Method Of Temperature Lag Effect In Deformation Monitoring Data Of Cable‑Stayed Bridge Structures, Liu Hongshuang, Zhai Wenqiang, Zeng Guoliang Dec 2024

Elimination Method Of Temperature Lag Effect In Deformation Monitoring Data Of Cable‑Stayed Bridge Structures, Liu Hongshuang, Zhai Wenqiang, Zeng Guoliang

Journal of China & Foreign Highway

There is a temperature lag effect in the deformation monitoring data of the bridge structure.Eliminating the temperature lag effect is of great significance in the health monitoring of the bridge structure.Based on the linear correlation between the deformation of the bridge structure and the temperature,this paper applied the goodness of fit test and proposed a time-domain translation elimination method.On this basis,by taking the long-term synchronous monitoring of the tower inclination,beam end displacement,main girder deflection,and temperature data of a cable-stayed bridge as an example,this method was used to eliminate the temperature lag effect in the deformation monitoring data and compared with …


Sensitivity Analysis Of Parameters Of Cable‑Stayed Bridges With Full Floating Spatial Frame, Liu Anqing, Yan Tengfei, Zheng Pengju, Gu Yanlin, Li Jie, Wang Qiang Dec 2024

Sensitivity Analysis Of Parameters Of Cable‑Stayed Bridges With Full Floating Spatial Frame, Liu Anqing, Yan Tengfei, Zheng Pengju, Gu Yanlin, Li Jie, Wang Qiang

Journal of China & Foreign Highway

In order to clarify the influence of design parameters on the mechanical behavior of a cable-stayed bridge of a floating system,a finite element model of the bridge was established by using the finite element analysis software MIDAS/Civil based on a single-tower double-cable plane steel-concrete composite beam cable-stayed bridge with full floating spatial frame.The sensitivity of parameters such as temperature effect,secondary dead load,and support system in the completed bridge state was analyzed and compared with the semi-floating system of the bridge.The results show that temperature and secondary dead load have a significant impact on the deflection and stress of the main …


Segment Connection Mod E For Stiffening Girder Hoisting Construction Of Long‑Span Steel Truss Girder Suspension Bridge, Shao Guangmiao, Pan Q Uan, Yan Donghuang, Xu Hongsheng Dec 2024

Segment Connection Mod E For Stiffening Girder Hoisting Construction Of Long‑Span Steel Truss Girder Suspension Bridge, Shao Guangmiao, Pan Q Uan, Yan Donghuang, Xu Hongsheng

Journal of China & Foreign Highway

In the process of stiffening girder construct ion of a long-span steel truss girder suspension bridge,different connection modes of stiffening girder segments will directly affect the internal force,alignment,and bridge state of the structure during construction.By taking the construction of the stiffening girder of a bridge as the research background,the finite element model of the whole process of the bridge was established.The advantages and disadvantages of the segmented hinge method and the segmented rigid connection method were compared,and the two-two segmented rigid connection scheme was proposed.On this basis,according to the changing law of steel truss section alignment and lower chord opening …


Linkage Control Method For Expressway Toll Stations And Plane Intersections, Lei Qing, Wang Zhaoyong, Wu Yurong, Jiang Weiwei, Luo Zhongbin Dec 2024

Linkage Control Method For Expressway Toll Stations And Plane Intersections, Lei Qing, Wang Zhaoyong, Wu Yurong, Jiang Weiwei, Luo Zhongbin

Journal of China & Foreign Highway

In order to solve the problem of vehicle queuing overflow caused by the mismatch between the expressway toll stations and the capacity of plane intersections,the formula for calculating the maximum queue length was given by analyzing the traffic operation characteristics between toll stations and plane intersections and considering vehicles ’ lane-changing behavior.Due to the strong coupling of the traffic operation between toll stations and plane intersections caused by a short distance between them,a unified linkage control optimization model was established.The research shows that if the queue length in the connecting direction of the plane intersections exceeds the allowable maximum queue …


Research On T‑Beam System With Diaphragm Based On Intelligent Construction, Liu Lang, Tao Qiyu, Xu Qigang Dec 2024

Research On T‑Beam System With Diaphragm Based On Intelligent Construction, Liu Lang, Tao Qiyu, Xu Qigang

Journal of China & Foreign Highway

The traditional precast T-beam faces issues such as excessive diaphragms,difficult formwork installation and removal,and low levels of intelligence in intelligent bridge construction.To address these issues,this paper focused on the optimization of the number of diaphragms and the application of prefabricated diaphragms.By analyzing different diaphragm configuration schemes and comparing the contributions of prefabricated diaphragms and precast diaphragms to the lateral stiffness of the bridge,this paper deeply explored the impact of diaphragms on bridge performance.The research results indicate that the T-beam system with fewer diaphragms is feasible in intelligent construction,but the system without diaphragms places higher demands on the performance of bridge …


3d Reconstruction Method Of Tunnel Surrounding Rock Fracture Based On Vtk, Liu Houxiang, Su Heng Dec 2024

3d Reconstruction Method Of Tunnel Surrounding Rock Fracture Based On Vtk, Liu Houxiang, Su Heng

Journal of China & Foreign Highway

Fracture parameters are important reference factors for surrounding rock stability analysis.To realize the visualization analysis of surrounding rock fractures,this paper proposed a three-dimensional (3D) reconstruction method of surrounding rock fractures based on the visualization toolkit (VTK).Firstly,the collected tunnel surrounding rock images were preprocessed by OpenCV for image grayscale and noise reduction.Secondly,the Otsu method and the open operation in morphology were used to segment the image,and the complete surrounding rock fracture map was obtained.Then,the median method was used to replace the linear interpolation method with the traditional Marching Cubes algorithm in VTK to calculate the equivalent point,and the improved Marching Cubes …


Experimental Study On Deformation Characteristics Of High Liquid Limit Soil Considering The Effect Of Temperature, Li Bangwu, Shen Xuning, Zhang Rui, Chen Yanrong Dec 2024

Experimental Study On Deformation Characteristics Of High Liquid Limit Soil Considering The Effect Of Temperature, Li Bangwu, Shen Xuning, Zhang Rui, Chen Yanrong

Journal of China & Foreign Highway

In order to study the influence of temperature on the absorbed bound water and deformation characteristics of high liquid limit soil,the high liquid limit soil in Hunan and Hainan provinces were selected for test.The influence of temperature on the content of bound water was measured by a temperature-controlled water bath volumetric flask test.The consolidation test was carried out on the samples with a one-dimensional temperature-controlled consolidometer,and the variation law of high liquid limit soil deformation affected by temperature was analyzed under the modified pore ratio considering the bound water content.The results show that the absorbed bound water in the high …


Surface Grouting Reinforcement Technology For Shallowly Buried Tunnel In Coastal Zone, Xiang Ze, Deng Shiping, Sheng Zhang, Zhou Ye, Wang Wei, Pei Yabing Dec 2024

Surface Grouting Reinforcement Technology For Shallowly Buried Tunnel In Coastal Zone, Xiang Ze, Deng Shiping, Sheng Zhang, Zhou Ye, Wang Wei, Pei Yabing

Journal of China & Foreign Highway

The Ⅵ level surrounding rock section of a project water intake tunnel is located in the coastal zone,with thick overlying sand layers,broken surrounding rock,and other characteristics.To address these issues,laboratory tests were conducted to explore the effect of water glass volume dosing on the final setting time and strength of cement-sodium silicate (CS) liquid slurry,and field tests were carried out for a comprehensive analysis of grouting methods.The constraint-dispersion mode was finally determined to divide the grouting area into several small grouting units.Advance plastic pipe grouting reinforcement was performed according to the grouting sequence of the outermost circle hole interval first,followed by …


Comparison Analysis Of Different Settlement Prediction Models Under Small Post‑ Constructio N Load On Soft Foundation, Han S Hanpeng, Fu Wei, Zhang Junhui, Lin Chen Dec 2024

Comparison Analysis Of Different Settlement Prediction Models Under Small Post‑ Constructio N Load On Soft Foundation, Han S Hanpeng, Fu Wei, Zhang Junhui, Lin Chen

Journal of China & Foreign Highway

Settlement deformatio n is a key conc ern in soft foundation construction.Since there is still a small load applied after the filling of soft foundation in the actual project,based on the settlement monitoring data of the high-fill section of Zhaoyang West Ring Expressway in Zhaotong City,Yunnan Province,three settlement prediction methods,namely the hyperbolic method,the three-point method,and the Hoshino method,were used to predict,compare,and analyze the settlement of the fill foundation,and the fitting characteristics of each model were summarized.By comparing the fitting curves and the actual settlement curves,it was found that the loading on the roadbed will cause large errors in the prediction …


Dynamic Response Analysis Of Bridge Under Combined Action Of Random Traffic Flow And Wind Based On Simpack Platform, Xiong Tao, Han Yan, Ma Xingchuan, Li Qianming, Yan Naijie, Zhang Fei, Hu Peng Dec 2024

Dynamic Response Analysis Of Bridge Under Combined Action Of Random Traffic Flow And Wind Based On Simpack Platform, Xiong Tao, Han Yan, Ma Xingchuan, Li Qianming, Yan Naijie, Zhang Fei, Hu Peng

Journal of China & Foreign Highway

To deal with the time-consuming problem of calculating the dynamic responses of the bridge under the combined action of random traffic flow and wind,a steel box continuous girder bridge was taken as the engineering background,and the finite element model of the bridge and the vehicle model were established in the commercial software Ansys and SIMPACK,respectively.Then,the dynamic responses of the bridge subjected to the single vehicle load,wind loads,and multiple vehicle loads were calculated to verify the superposability of the dynamic responses of the bridge.On this basis,the Monte Carlo method was used to generate the random traffic flow samples.By using the verified …


Research Progress Of Rubber‑Modified Asphalt By Wet Process, Ge Dongdong, Jiang Xiangyang, Lyu Songtao, Zhang Honggang, Song Xiaojin Dec 2024

Research Progress Of Rubber‑Modified Asphalt By Wet Process, Ge Dongdong, Jiang Xiangyang, Lyu Songtao, Zhang Honggang, Song Xiaojin

Journal of China & Foreign Highway

The application of waste tires in asphalt pavements can not only effectively reduce resource consumption but also significantly reduce environmental pollution.Crumb rubber could be obtained by processing waste tires and used as a modifier by mixing with asphalt through the wet process to improve the performance of asphalt.This paper reviewed the research progress of rubber-modified asphalt by wet process and discussed its preparation process,influencing factors of performance,and modification mechanism.By reviewing the relevant studies,the critical conditions in the preparation process and their effects on storage stability were summarized.Furthermore,the effects of rubber dosage,particle size,matrix asphalt type,and preparation parameters on the physical and …