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Full-Text Articles in Civil and Environmental Engineering

General Hydrogeochemical Characterization Of Groundwater In Coastal Aquifers Of Kilwa Kisiwani Oceanic Island, South East Tanzania, Simon R Melchioly Apr 2024

General Hydrogeochemical Characterization Of Groundwater In Coastal Aquifers Of Kilwa Kisiwani Oceanic Island, South East Tanzania, Simon R Melchioly

Tanzania Journal of Engineering and Technology (TJET)

The main objective of this study was to determine the hydrogeochemical processes controlling the groundwater chemistry on the Island and assess its suitability for human consumption and irrigation. The methodology used in the study include hydrogeological assessment of the study area and laboratory analysis for general physico-chemical parameters of groundwater. Other parameters such as Soluble sodium percentage (SSP) or % Na+, Sodium Adsorption Ratio (SAR), Magnesium adsorption ratio (MAR), Residual sodium carbonate (RSC), hydrochemical facies classification, and Water Quality Index (WQI) were calculated using empirical formulae. The effects of salinization of groundwater were classified using the chloride-Bicarbonate (Cl/HCO3) and the …


Causes And Consequences Of Inefficient Drilling And Blasting In Mine Development Headings: A Case Study Of Hard Rock Gold Mining Operations In Northern Tanzania, George Bennett Apr 2024

Causes And Consequences Of Inefficient Drilling And Blasting In Mine Development Headings: A Case Study Of Hard Rock Gold Mining Operations In Northern Tanzania, George Bennett

Tanzania Journal of Engineering and Technology (TJET)

Despite the introduction of the perimeter blasting technique at the Tulawaka Gold Mine, the mine continued to suffer from an overbreak of mine development headings, with an average overbreak of 24% every 22 m, which is approximately twice the acceptable 10% overbreak. The causes of this problem include ineffective drilling practices and uneven and excessive charging of explosives, resulting in a slightly high powder factor of 3.94 kg/m3 instead of 3.8 kg/m3, as per the design. The problem of overbreak resulted in ore dilution, a longer mine development cycle time and additional costs of approximately US$ 45 per cut, especially …


Designed For Life: Unearthing Just And Sustainable Urban Design Through The Daylighting Of Phalen Creek, Corgan R. Archuleta Apr 2024

Designed For Life: Unearthing Just And Sustainable Urban Design Through The Daylighting Of Phalen Creek, Corgan R. Archuleta

Geography Honors Projects

This thesis conceptualizes a relational approach to urban design. Often separated from justice, I argue urban design can shape spaces to enable respectful and reciprocal human and more-than- human relationships. Focusing on Phalen Creek in Saint Paul, Minnesota, I illuminate just and sustainable possibilities between ecologically sustainable and socially inclusive design. Phalen Creek was a natural waterway buried in a pipe during 20th century urbanization to be partially reconstructed through daylighting. The Indigenous and Immigrant stories driving restoration expand urban design’s liberatory potential. Combining just sustainabilities with infrastructure theory and Indigenous Knowledges, I contend urban design offers a relational approach …


A 2-D Numerical Model For Evaluating Daylight Penetration In Short Tunnels For Enhanced Driver Safety, Joachim James Apr 2024

A 2-D Numerical Model For Evaluating Daylight Penetration In Short Tunnels For Enhanced Driver Safety, Joachim James

Master's Theses

It is commonly assumed that daylight will adequately penetrate short tunnels, leading to the misconception that artificial lighting is unnecessary during the daytime. Past studies revealed higher frequency of crashes in short tunnels and despite that there is lack of national guidelines warranting artificial lighting for short tunnels. Inadequately lit tunnels pose safety risks, while excessive lighting can be costly. Hence, it becomes crucial to investigate the extent of daylight penetration in short tunnels and identify disappearance zones within these tunnels. This research can help determine the necessity of artificial lighting, and which specific areas of the tunnel require lighting. …


Microplastics Fouling Mitigation In Forward Osmosis Membranes By The Molecular Assembly Of Sulfobetaine Zwitterion, Javad Farahbakhsh, Mitra Golgoli, Mehdi Khiadani, Amir Razmjou, Masoumeh Zargar Apr 2024

Microplastics Fouling Mitigation In Forward Osmosis Membranes By The Molecular Assembly Of Sulfobetaine Zwitterion, Javad Farahbakhsh, Mitra Golgoli, Mehdi Khiadani, Amir Razmjou, Masoumeh Zargar

Research outputs 2022 to 2026

Forward osmosis (FO) membranes have potential for the efficient water and wastewater treatment applications. However, their development has faced significant challenges due to their fouling propensity. In this study, FO membranes modified with sulfobetaine zwitterions (i.e., [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide) were fabricated and used for the first time to address microplastic (MP) fouling issue. Water flux, reverse salt flux (RSF), fouling, and flux recovery were evaluated for the membranes loaded with different quantities of the zwitterions ranging from 0.25 % to 2 %. The developed membranes were tested over 49 h with feed solutions containing polyethylene MPs and bovine serum albumin …


Time-Scale Of Groundwater Recharge In Coastal Plain Soils, Qing Du Apr 2024

Time-Scale Of Groundwater Recharge In Coastal Plain Soils, Qing Du

USF Tampa Graduate Theses and Dissertations

Understanding and modeling the timing and magnitude of groundwater recharge fromrainfall infiltration through vadose zone percolation is important for many reasons but especially because the flux is being acted on by root zone evapotranspiration (ET) and very little of rainfall infiltration ever becomes water table recharge. This study elaborates on the considerable time of the wetting front arrival and ultimate bulk recharge of rainfall infiltration in shallow water table fine-sandy soils typical of coastal plain environments such as Florida. Calibrated Hydrus-1D modeling of Florida (Myakka) soil was evaluated at varying depths of water table and hydraulic conductivities to bracket the …


Seeding Effects Of Submicron Caal-No3 Ldh Particles On The Hydration And Properties Of Portland Cement And Sulfoaluminate Cement Pastes, Sukanta K. Mondal, Monday Uchenna Okoronkwo Apr 2024

Seeding Effects Of Submicron Caal-No3 Ldh Particles On The Hydration And Properties Of Portland Cement And Sulfoaluminate Cement Pastes, Sukanta K. Mondal, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Layered double hydroxide (LDH) is reported to improve the durability of concretes, primarily due to its ability to exchange anionic species, including chloride, which is implicated in corrosion-driven durability issues. However, there is no comprehensive study investigating the effect of LDH on the properties of different cement systems at both early and mature ages. in this study, the early age and mature age properties of Portland cement (OPC) and calcium sulfoaluminate (CSA) cement pastes seeded with submicron-sized calcium aluminum-NO3 LDH (CaAl-NO3 LDH) were investigated. the effects of the 1–5%mass dosage of LDH on the hydration of both cement systems were …


10 Meters To Disaster: The Challenges Of Premature Application Of Circular Economy Strategies In Jakarta’S Waste Management Structure, Almira Bowo Apr 2024

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

Independent Study Project (ISP) Collection

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


Transport Of Multi-Phase Multi-Component Fluids In The Shallow Subsurface Influenced By Soil And Surface Boundary Conditions: Experimental And Numerical Study With Application To Natural Gas Leakage, Navodi Jayarathne Apr 2024

Transport Of Multi-Phase Multi-Component Fluids In The Shallow Subsurface Influenced By Soil And Surface Boundary Conditions: Experimental And Numerical Study With Application To Natural Gas Leakage, Navodi Jayarathne

Civil and Environmental Engineering Theses and Dissertations

With the increased use of Natural Gas (NG) as a source of fuel, underground leak-related events are increasingly reported, and some are fatal. Subsurface migration and development up to flammable limits are highly dependent on leak characteristics, soil, atmospheric variables, and other surface and subsurface structural complexities. Although few studies have characterized the transient behavior of leaked NG in the shallow subsurface, the underlying mechanisms and their interactions are not well understood, which prevents prediction of the impact of environmental and operating conditions on gas migration. The study conducted a series of field scale-controlled release experiments and numerical simulations to …


Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu Apr 2024

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

Civil & Environmental Engineering Theses & Dissertations

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


Advancing Depth-Storage-Discharge Modeling In Regional Hydrology, Fahad Alshehri Mar 2024

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

USF Tampa Graduate Theses and Dissertations

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


Bear Lake Session, Lawrence Culver, Ben Shaw, Wesley Matthis, Mario Harper Mar 2024

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

Spring Runoff Conference

No abstract provided.


Leveraging Systems Thinking For Global Environmental Health, Martha M. Mcalister Mar 2024

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

USF Tampa Graduate Theses and Dissertations

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


Key Construction Techniques For Incremental Launching And High Falling Beam Of Long‑Span Simply Supported Steel Box Girder, Wu Yanbin, Lyu Maofeng, Yin Qijia, Yu Guanqiu Mar 2024

Key Construction Techniques For Incremental Launching And High Falling Beam Of Long‑Span Simply Supported Steel Box Girder, Wu Yanbin, Lyu Maofeng, Yin Qijia, Yu Guanqiu

Journal of China & Foreign Highway

Based on the overpass project over Beijing-Hong Kong-Macao Expressway on Changsha Pan-Pan Road,this paper proposed a construction method of large-slope walking-type incremental launching and high falling beam of steel box girder given the difficulties in busy traffic under the bridge,large pushing slope,and great total height of falling beam.After the steel box girder assembly was completed,some bridge deck ancillary facilities were constructed in advance in the preassembly yard and the weight was allocated.The steel box girder was pushed synchronously,thereby reducing the aerial work on the bridge in the later stage.During the incremental launching construction of the steel box girder above the …


Different Forms Of Nano‑Sio2 In Emulsified Asphalt And Their Effects On Emulsion Storage Stability, Ji Chao, Cao Yuanhao, Li Zhigang Mar 2024

Different Forms Of Nano‑Sio2 In Emulsified Asphalt And Their Effects On Emulsion Storage Stability, Ji Chao, Cao Yuanhao, Li Zhigang

Journal of China & Foreign Highway

The insufficient storage performance of emulsified asphalt has always been a problem affecting its application,and there have been studies in China on nano-SiO2 particles as additives to improve the stability of emulsified asphalt,but the effect is not obvious.Based on the principle of Pickering emulsion,nano-SiO2 with surface modification was used as an emulsifier to directly emulsify matrix asphalt,and whether its stability improvement effect on emulsified asphalt is better than nano-SiO2 as a modified additive was explored.Firstly,three emulsified asphalt were prepared,namely ordinary modified emulsified asphalt A,emulsified asphalt B with nano-SiO2 as a modified additive,and emulsified asphalt C based on the new nano-SiO2 …


Study On Test Methods Of Wheel Sticking‑Free Emulsified Asphalt, Wang Peng, Qin Yongchun, Wang Jie, Xiong Weiming, Chang Rong, Fu Chongfeng, Feng Guoli Mar 2024

Study On Test Methods Of Wheel Sticking‑Free Emulsified Asphalt, Wang Peng, Qin Yongchun, Wang Jie, Xiong Weiming, Chang Rong, Fu Chongfeng, Feng Guoli

Journal of China & Foreign Highway

The wheel sticking-free emulsified asphalt is a key material to solve the wheel sticking problem in the process of asphalt pavement construction,with the wheel sticking-free effect as the core index.The accurate evaluation of the wheel sticking-free effect is important for the popularization and application of wheel sticking-free emulsified asphalt.Based on the research results in China and abroad,two test methods for wheel sticking-free effects (counterweight method and indenter method ) were innovatively proposed,and the wheel sticking-free effects of various emulsified asphalt were evaluated.The test results show that the two test methods can accurately evaluate the wheel sticking-free performance of emulsified asphalt,and …


Study On Mobilization Rate Of Rap Aged Asphalt Based On Ftir, Zou Xiaoyong, Li Ning, Wu Wenxiu, Wang Xin, Xu Xiaohe Mar 2024

Study On Mobilization Rate Of Rap Aged Asphalt Based On Ftir, Zou Xiaoyong, Li Ning, Wu Wenxiu, Wang Xin, Xu Xiaohe

Journal of China & Foreign Highway

During the preparation of the recycled asphalt mixture,part of the aged asphalt is first transferred from the surface of the recycled material to the new aggregate and then diffused and fused with the new asphalt,in which the percentage of transferred aged asphalt plays a key role in the final regeneration effect.In order to study the degree of transfer of aged asphalt in reclaimed asphalt pavement (RAP ),the mobilization rate (RMR) was calculated and analyzed based on the Fourier transform infrared spectroscopy (FTIR ).The AC-13 graded recycled asphalt mixture was mixed and sieved to separate the new aggregate and RAP.The recycled …


Deflection Variation Rule Of Main Girder For A Concrete Cable‑Stayed Bridge Based On Combined Static And Dynamic Modification, Li Qi, Qi D Ongchun, Yang Hu, Zhao Zhiguo Mar 2024

Deflection Variation Rule Of Main Girder For A Concrete Cable‑Stayed Bridge Based On Combined Static And Dynamic Modification, Li Qi, Qi D Ongchun, Yang Hu, Zhao Zhiguo

Journal of China & Foreign Highway

In order to solve the problem of continuous downward deflection of the main girder for a concrete cable-stayed bridge during its service life,the deflection variation of the main girder for a long-span concrete cable-stayed bridge during its service was analyzed based on the modified model.A dual-objective optimization problem was constructed by using the combined static and dynamic finite element model modification method and was solved by the non-dominated sorting genetic algorithm (NSGA- Ⅱ).The Pareto optimal solution set was obtained,and the coordinated optimal solution was found in the Pareto optimal solution set,so as to modify the finite element model.The calculated values …


Construction Technology Of Reactive Powder Concrete Prestressed Box Girder, Wang Xiaojie Mar 2024

Construction Technology Of Reactive Powder Concrete Prestressed Box Girder, Wang Xiaojie

Journal of China & Foreign Highway

At present,high-strength and high-performance concrete has some disadvantages,such as low flexural strength,large brittleness,and poor volume stability.Reactive powder concrete (RPC ) is a new type of material,which has good mechanical properties and high impermeability.It can reduce the amount of concrete to a greater extent and reduce the weight of the structure,achieving the purpose of safety,reliability,and cost saving.This paper applied RPC to highway prestressed box girder.Through the innovation and optimization of mix ratio,the change in traditional transportation technology,and curing technology research of steam curing shed,it effectively shortens the pouring time of RPC,ensuring the pouring quality and strength.


Fragilit Y Analysis Of Continuous Rigid Frame Bridge With High Piers And Long Span Subjected To Near‑Field Earthquakes, Sun Yongjiang Mar 2024

Fragilit Y Analysis Of Continuous Rigid Frame Bridge With High Piers And Long Span Subjected To Near‑Field Earthquakes, Sun Yongjiang

Journal of China & Foreign Highway

Near-field earthquakes are more destructive to the continuous rigid frame bridge with high piers and long span.Based on a new-built continuous rigid frame bridge with high piers and long span,considering the seismic demand probability of bridges under near-field earthquakes,this paper utilized OpenSees to analyze the time history of the bridge.The structure response of the bridge under near-field earthquakes was obtained by the nephogram method,and the vulnerability of the bridge under earthquake was analyzed based on the curvature demand probability model of the structure.The results show that the probability response of curvature demand of a continuous rigid frame bridge with high …


Lightweight Replacement Technology For Existing Soft Subgrade Based On Over‑Consolidated State, Huang Baotao, Zhang Mudan, Huang Xiangshuo, Fang Mingshan, Feng Jianxue, Huang Lizhen Mar 2024

Lightweight Replacement Technology For Existing Soft Subgrade Based On Over‑Consolidated State, Huang Baotao, Zhang Mudan, Huang Xiangshuo, Fang Mingshan, Feng Jianxue, Huang Lizhen

Journal of China & Foreign Highway

In order to solve the differential settlement of soft subgrade in coastal areas,based on the elastic deformation theory of overconsolidation stress ratio,the calculation and analysis of artificial overconsolidation stress ratio and the new technology of lightweight replacement were carried out to reduce the additional stress of vehicle load and structure weigh.The results show that the replacement thickness of the lightweight material with suitable density can make the additional stress at the bottom of the subgrade less than the deadweight stress of the original soft soil,and the additional stress is less than the initial flow stress of the soft soil.The resulting …


Analysis Of Stress And Drainage Characteristics Of Water Film Between Tire And Road Surface And Influence Of Groove Parameters, Sun Zhenhao, Chen Jun Mar 2024

Analysis Of Stress And Drainage Characteristics Of Water Film Between Tire And Road Surface And Influence Of Groove Parameters, Sun Zhenhao, Chen Jun

Journal of China & Foreign Highway

In order to study the stress characterist ics of water film on cement concrete road surface under the action of the tire and the influence of grooves,the finite element model of tire-water film-road surface was constructed using SolidWorks and Ansys Workbench.Based on computational fluid dynamics (CFD ) control equation and fluid-structure coupling theory,the flow law of water film on road surface under the action of the tire and the influence of water film thickness,driving speed,groove width,groove spacing,and groove direction on the hydrodynamic lift of tire were analyzed.The results show that the hydrodynamic lift of the tire increases with the increasing …


Influence Of Rap Content On Mechanical Properties And Pavement Performance Of Warm Recycled Asphalt Mixture, Ren Ruibo, Yin Liyang, Xu Qiang, Zhao Pinhui, Ma Shidong Mar 2024

Influence Of Rap Content On Mechanical Properties And Pavement Performance Of Warm Recycled Asphalt Mixture, Ren Ruibo, Yin Liyang, Xu Qiang, Zhao Pinhui, Ma Shidong

Journal of China & Foreign Highway

Warm recycling technology is an effective new technology for recycling recycled asphalt pavement (RAP ).In order to improve the pavement performance of warm recycled asphalt and effectively enhance the recycling rate of RAP,the influence of RAP content on the performance of warm recycled asphalt mixture was investigated through mechanical properties and pavement performance analysis,and the correlation between dynamic stability and mechanical parameters of creep tests under repeated loading was discussed.The results show that with the increase in RAP content,the high-temperature stability,shear resistance,and elastic deformation resistance of warm recycled asphalt mixture are improved,but the low-temperature crack resistance and water stability are …


Expressway Traffic Flow Prediction Based On Data From Multiple Related Toll Stations, Zhang Yang, Yao Fangyu, Yang Shumin Mar 2024

Expressway Traffic Flow Prediction Based On Data From Multiple Related Toll Stations, Zhang Yang, Yao Fangyu, Yang Shumin

Journal of China & Foreign Highway

The strong inter-economic connection makes a spatial correlation between traffic data from multiple related toll stations between urban cluster regions,and an accurate description of this connection can improve the accuracy of expressway traffic flow prediction.However,due to many uncertainties,the correlation is difficult to be captured and quantified.To solve this problem,an ATGCN-ResGRU deep learning-based expressway traffic flow prediction method was proposed.By combining attention mechanisms,three graph convolutional networks (GCN ) topological networks with high,medium,and low attention levels were constructed,and spatial learning data was obtained according to the weighted attention level of each network.The connection of multiple related toll stations was quantified and graded.At …


Carbon Emission Calculation And Scheme Selection For Roadbed Drainage Ditches By Mechanized Construction, Xing Hao, Wu Jiarun, Li Han, Lin Yuliang, Guo Dongdong Mar 2024

Carbon Emission Calculation And Scheme Selection For Roadbed Drainage Ditches By Mechanized Construction, Xing Hao, Wu Jiarun, Li Han, Lin Yuliang, Guo Dongdong

Journal of China & Foreign Highway

Aligned with the peak carbon and neutrality goals,the mechanized construction of roadbed drainage ditches should consider not only construction efficiency and economic factors but also carbon emissions.This study,centered on the Meng-LYU highway,devised approaches to calculate roadbed drainage ditches' carbon emissions and investment costs across three stages:building material production,transportation,and construction.By introducing the concept of carbon trading to align carbon emissions and investment costs,a comprehensive comparison was conducted between the conventional supporting formwork method and the hydraulically powered sliding formwork method regarding equivalent carbon emissions.An orthogonal experiment was conducted involving the upper length of the roadbed drainage ditch,pouring thickness,haul distance,and construction length …


Study On Treatment Method Of Expansive Soil Embankment In Expressway Reconstruction And Extension, Wang Yuwei, Hu Yanli, Zhang Rui Mar 2024

Study On Treatment Method Of Expansive Soil Embankment In Expressway Reconstruction And Extension, Wang Yuwei, Hu Yanli, Zhang Rui

Journal of China & Foreign Highway

In order to fully utilize expansive soil as filler in highway reconstruction and expansion projects,this paper draws on the successful experience of using expansive soil directly in road construction.It proposes an embankment treatment scheme that involves the use of geogrid-reinforced expansive soil with edge wrapping,based on the reconstruction and expansion project of the Hefei to Dagudian section of the G 40 Shanghai-Shaanxi Expressway.Through laboratory tests,the road performance and swelling characteristics of the expansive soil filler were investigated to determine the applicable scope and compaction control indices of the filler.Then,the feasibility of the embankment treatment scheme was demonstrated through the prediction …


Prediction Method Of Surrounding Rock Deformation Of Highway Tunnels Based On Bayes‑Lstm, Liu Zhi, Li Xinyu, Li Zhen, Kong Xianguang, Chang Jiantao Mar 2024

Prediction Method Of Surrounding Rock Deformation Of Highway Tunnels Based On Bayes‑Lstm, Liu Zhi, Li Xinyu, Li Zhen, Kong Xianguang, Chang Jiantao

Journal of China & Foreign Highway

In the process of highway tunnel construction,the stability of surrounding rock has a great impact on tunnel construction.Therefore,the monitoring measurement and accurate prediction of surrounding rock deformation of highway tunnels are the keys to ensuring the safety of tunnel construction.In view of the low prediction accuracy and poor generalization ability of tunnel surrounding rock deformation,this paper proposed a Bayesian (Bayes )-based method to optimize the long-term and short-term memory (LSTM ) network.The method first preprocessed the original monitoring data of crown settlement and peripheral convergence,then constructed the initial LSTM model of crown settlement and peripheral convergence of highway tunnels,and used …


Comparative Analysis Of Test Results Of Different Nano‑Clay Improved Loess, Zhao Danni, Cao Baohua, Xu Jiangbo, Nan Yalin, Chen Nengyuan, Zhang Peng, Wang Heping Mar 2024

Comparative Analysis Of Test Results Of Different Nano‑Clay Improved Loess, Zhao Danni, Cao Baohua, Xu Jiangbo, Nan Yalin, Chen Nengyuan, Zhang Peng, Wang Heping

Journal of China & Foreign Highway

The orthogonal design t est was used to quantitatively analyze the influencing factors and influence degree of compressive strength,shear strength index,and permeability coefficient of improved loess,and the optimal content of improved loess was obtained.In addition,the improvement mechanism of nano-clay materials on loess was explored by scanning electron microscopy.The results show that:① The factors affecting the compressive strength of improved loess are the content of nano-clay,water content,and curing age,and the factors affecting cohesion,internal friction angle,and permeability coefficient are the content,dry density,and confining pressure.② Under different influencing factors,nano-montmorillonite can effectively improve the compressive strength of loess than attapulgite.③ When the material content …


Technical Essentials Of Road Geometric Design In Serbia, Xu Da, Yang Xueyong, Yuan Yingshuang, Chen Dongsheng Mar 2024

Technical Essentials Of Road Geometric Design In Serbia, Xu Da, Yang Xueyong, Yuan Yingshuang, Chen Dongsheng

Journal of China & Foreign Highway

With the continuous advancement of China's Belt and Road Initiative,more and more Chinese enterprises are participating in the construction of engineering projects in Central and Eastern Europe,which brings some challenges for designers to master and use local codes for engineering design and consultation.According to the concrete practice of road reconstruction design of Hungary-Serbia Railway (Serbia section ),the application of horizontal and vertical indexes in road geometric design in Serbian was summarized.It is found that road design in Serbian has perfect design standards and systems.The Serbian code and the Chinese code are relatively close in terms of road geometric design standards,and …


Effect Evaluation Method Of Foamed Asphalt Based On Digital Image Processing Technology, Chang Xiaoyu Mar 2024

Effect Evaluation Method Of Foamed Asphalt Based On Digital Image Processing Technology, Chang Xiaoyu

Journal of China & Foreign Highway

In view of the shortage of deter mining the optimal foaming parameters of foamed asphalt only by experience,this paper adopted digital image processing technology to collect images of the mixture of foamed asphalt and milled material RAI obtained under different foaming conditions and carried out grayscale image conversion,morphological processing,binary image conversion,and image segmentation,so as to calculate the asphalt wrapping rate in different areas.With the uniform dispersion of asphalt in the mixture as the indicator,the foaming effect of foamed asphalt was evaluated,and the optimal foaming parameters were determined.The results show that the digital image processing technology can quickly and effectively evaluate …