Other Civil and Environmental Engineering Commons^™

Anti‑Freezing Performance Of Cement-Stabilized Mixture For Recycled Aggregate From Solid Construction Waste, Zheng Jiajia, Zhang Laijun, Wang Xihui, Xie Jianwei, Chen Zhiyong

Journal of China & Foreign Highway

This paper investigated the effects of particle size and content of recycled aggregate on the anti-freezing performance of cement-stabilized recycled aggregate mixture,so as to provide a reference for the fine utilization of recycled aggregate with different particle sizes.The basic performance indexes of recycled aggregates with different particle sizes were tested,and the optimum moisture content and maximum dry density were determined by compaction test.The specimens were prepared with 4% cement content,and the anti-freezing performance of the mixture was evaluated by testing the unconfined compressive strength loss of the mixture after the freeze-thaw cycle.The results show that the optimum moisture content increases,and …

Experimental Study On Road Performance Of Resin Elastomer For Seamless Expansion Joints Of Bridges, Zhou Wei, Sheng Liang, Gao Qin, Zhang Hui, Zhao Menglong

Journal of China & Foreign Highway

Seamless expansion joint is a new type of bridge expansion joint.In order to study the road performance of resin elastomer for seamless expansion joints,the feasibility of applying resin elastomer to small and medium displacement expansion joints of bridges was explored.Through the rutting test at 60 ℃, low-temperature beam bending test at −10 ℃,dynamic modulus test,Poisson's ratio test,and overlay test (OT),the high and low temperature stability,deformation performance,and fatigue crack resistance of the resin elastomer were compared.The test results show that the dynamic stability of the resin elastomer at 60 ℃ is more than 31 000 times/mm,and the bending strain at low …

Experimental Study On Adhesive Pe Rformance Of Second-Order Thermosetting Epoxy Asphalt In Bridge Deck Pavement, Zhou Changdong, Dai Mingjing, Zhao Mingyu, Li Zhiqiang, Lei Yuxiang, Ding Qingjun

Journal of China & Foreign Highway

Based on the Wujiagang Yangtze River bridge project in Yichang,the interfacial shear strength and pull-out strength of the second-order thermosetting epoxy asphalt material between RA asphalt concrete and high viscoelastic SMA asphalt concrete in pavement structure were studied under different spraying amount,different first-stage curing time,different curing time,and different service temperatures.In addition,the influence of spraying amount on shear fatigue resistance was studied.The results show that with the increase in the spraying amount of the second-order thermosetting epoxy asphalt,the adhesive performance and shear strength are improved,and the shear fatigue resistance of the structure is enhanced.At a construction ambient temperature of 25‒35 ℃,the …

Design And Key Technologies Of Bridges With Long‑Cantilever Closed Steel Box Composite Girder, Ji Jiandong, Wang Bin

Journal of China & Foreign Highway

In order to meet the span requirements of bridges over the Yellow River and reduce the interference of temporary construction facilities on flood discharge from the Yellow River,the Linyi Yellow River Bridge was studied.The main bridge adopted a continuous long-cantilever closed steel box composite girder of (112 + 28 × 128 + 120) m and was divided into two parts,with the maximum length of the parts being 1 912 m.The steel box composite girder was constructed by incremental launching method without temporary piers,and the bridge deck was installed after the closed steel box girder was in place.The installation sequence of …

Supporting Capacity Anal Ysis And Construction Scheme Optimization Of Support System For Cast‑In‑Situ Box Girders In High‑Pier Wading Bridges, Guo Tao, Yao Yuchen, Ma Hongze, Huang Xiaomin, Zhang Yongchun

Journal of China & Foreign Highway

Although a concrete bridge su pport system is a temporary structure,it still has a supporting capacity.With the development of bridge engineering,concrete bridges with high piers and long spans are gradually applied in deep reservoir areas,and the forces on scaffolding are more and more complex.Traditional manual calculations in structural mechanics can no longer completely reflect the stress-strain states of scaffolding with irregular configurations,special parts,and uncommon conditions.Thus,it is necessary to use a numerical method to calculate the supporting capacity of scaffolding and design construction schemes.This paper took a concrete wading bridge with high piers as an example.An evaluation method based on the …

A Rapid Test Method For Deflection Of Small And Medium‑Span Bridges, Zhang Aipin, Ma Lindong, Chang Zhugang, Fan Zhihao

Journal of China & Foreign Highway

Bridge deflection response is on e of the most important indicators used for structural condition assessment of bridges.There are currently many methods and devices for deflection measurement,but they are not satisfying in terms of economy,applicability,and measurement accuracy at the same time.This paper proposed a rapid and highly accurate method for measuring mid-span deflection of small and medium-span bridges.By using the high accuracy of displacement transducers in direct contact measurement,an auxiliary measurement device was developed to transfer the deflection of the measurement points on the bridge to the displacement transducer in the form of a rigid connection,thus achieving accurate and dynamic …

Numerical Simulation Of Mechanical Performance For Anti‑Collision Steel Pontoon, Han Xiaolei, Wang Bo, Li Weidong

Journal of China & Foreign Highway

Anti-collision steel pontoo n has good plasticity and energy absorption properties in ship-bridge collision.To explore the factors affecting the anti-collision performance of the anti-collision pontoon,a collision model composed of ship,anti-collision pontoon,and pier system was built based on finite element software Ansys/LS-DYNA.The collision mechanism and process were numerically simulated,and the effects of connection type between anti-collision pontoon and pier,peak angle of pontoon,and anti-collision pontoon stiffness on the collision force of the pier were investigated.The three-stage division method of collision force curve was put forward.The analysis shows that the fixed inwall of the anti-collision steel pontoon and connection to the pier surface …

Deformation And Damage Characteristics Of A Newly Operated Tunnel Caused By Above Foundation Pit Construction, Liu Jiqiang, Zhu Min, Hao Kun, Chen Dengwei, Chen Xiangsheng

Journal of China & Foreign Highway

The construction of foundation pits in granite residual soil layers is prone to causing upheaval deformation and structural damage in shield tunnels below.Based on the engineering case of a newly operated metro tunnel collinear with the above long-distance deep foundation pit in Shenzhen,a three-dimensional finite element model was established to investigate the variation law of the heave and horizontal convergence of the shield tunnel caused by the deep foundation pit excavation.The correlation between the longitudinal stress of the lining structure and the damage was analyzed.The results indicate that the tunnel deformation caused by foundation pit unloading is primarily vertical heave,accompanied …

Dynamic Response Rules Of Adjacent Buildings To Blasting Construction In Shallow Buried Tunnels, Luo Yanping, Li Jigang, Wang Sheng, Zeng Bin, Lai Jinxing, Feng Zhihua, Qiu Junling

Journal of China & Foreign Highway

In order to study the dynamic response rule of overlying buildings during blasting construction in shallow buried tunnels,the urban tunnel in Fuzhou was taken as the engineering background,and the on-site monitoring and Ansys/LS-DYNA simulation were used to analyze the structural response of overlying buildings.The monitoring results show that the building is most obviously affected by blasting in the vertical direction and has an obvious elevation amplification effect,and the maximum vibration velocity is 2.45 cm/s.The vibration velocity in all directions gradually decreases and tends to be stable with the increase in explosion center distance and decays rapidly when the explosion center …

Deflection Basin Characteristics Of Distressed Roads Under Moving Load, Cai Yingchun, Xie Shenjian

Journal of China & Foreign Highway

The deflection basins of roads under moving load imply the distress information of subgrade and pavement.Therefore,how to use the information of deflection basins under moving load to rapidly test road distresses non-destructively has received much attention.In this paper,the finite element model of semi-rigid base asphalt pavement was established.By setting different types and degrees of finite element distress models,the continuous changes of surface deflection basins under moving load were analyzed.The results show that when the load moves to the distress area,the center deflection value of surface deflection basins in each distress model will become larger.When transverse cracks appear in the pavement …

Curing Mechanism And Influencing Factors Of Cement Mixing Piles Reinforcing Peat Soil, Feng Rongxian, Zhong Gaibing, Liu Liang, Liang Jianyuan, Gu Meixiang

Journal of China & Foreign Highway

The cement mixing pile is used to reinforce the deep peat soil foundation in Malaysia's east coast railway construction.The key in this project is to determine the cement mix proportion and additives.Considering the high organic matter content and strong environmental acidity of coastal peat soil,physical and mechanical tests of peat soil and laboratory uniaxial compression tests of cement soil under different mix proportions and influencing factors were conducted.Test results show that the mean compressive strength decreases by 0.35 MPa with the increase in cement-water from 0.5 to 0.9.Adding mineral powder gives a relatively poor curing effect while adding fly ash …

Safety Of Optimized Concrete Median Barrier Without Planting Soil, Zhong Chunyao, Ma Qing, Li Yangfan, Gong Shuai, Liu Siyuan, Yan Shuming

Journal of China & Foreign Highway

In order to study the safety of optimized concrete median barrier without planting soil,the technology combining computer simulation,sled test,and full-scale impact test of real vehicles was adopted for analysis and verification.In addition,a scheme was proposed to improve the anti-overturning ability of the barrier without planting soil by strengthening the supporting block,and the scheme of setting a 20 cm-high supporting block between the barrier walls was optimized.The safety of the barrier scheme was evaluated by taking the most unfavorable large truck as an example.The results show that the protection level of the optimized concrete median barrier without planting soil is SAm, …

Aided Design Method And Application Of Rutting Prevention And Maintenance In Asphalt Pavement Based On Digital Holographic 3d Detection, Wang Jingfei, Wang Wang, Xu Xinquan, Huang Zhijian, Ti Jing, Yao Yanru

Journal of China & Foreign Highway

As one of the common diseases of asphalt pavement,rutting has significant impacts on the service life and traffic safety of the pavement.Mild rutting in asphalt pavement during preventive maintenance can lead to increased use of maintenance materials due to rutting deformation.Accurately calculating the amount of materials needed to fill rutting in maintenance designs is of great significance for ensuring maintenance quality and efficiency.Based on the requirements of maintenance engineering,this paper analyzed the problems in maintenance designs that use traditional methods and the data they generate for rutting detection.A design method was proposed for rutting prevention and maintenance in asphalt pavement,assisted …

Evaluation Of Coal Transport Route In Jambi City (Talang Duku Port-East Ring Road Ii), Dwi Angella, Sutanto Soehodho, Nahry Nahry

Smart City

In its implementation, the role of coal transportation infrastructure is important in supporting the mining industry in Jambi City. However, it also causes various complex problems; one of them is traffic congestion on arterial roads in Jambi City. In May 2023, the Jambi Regional Police of the Republic of Indonesia issued a notification letter to stop the mobilization of coal transportation in Jambi Province. The policy caused several coal companies to switch their transportation method to shipping in order to continue operating, while several other companies stopped operating until an indeterminate time. Therefore, this study aims to compare traffic performance …

Sensitization Of Europium Oxide Nanoparticles Enhances Signal-To- Noise Over Autofluorescence With Time-Gated Luminescence Detection, Hunter Miller, Jessica Q. Wallace, Hui Li, Xing-Zhong Li, Ana De Bettencourt-Dias, Forrest Kievit

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Clinical translation of nanoparticle-based therapeutics has been limited, and a lack of preclinical delivery characterization is partly to blame, limiting our understanding of the mechanisms of failure. The improvement of the preclinical delivery assessment requires nanoparticles with higher detectability. This work focused on the exploration of several aromatic carboxylic ligands (terephthalic acid, quinaldic acid, and kynurenic acid) for the sensitization of europium oxide nanoparticles with a long emission lifetime to overcome cellular autofluorescence, a key confounder of detection in luminescence-based bioimaging. A facile one-pot synthesis and ligand exchange process generated and sensitized ultrasmall Eu₂O₃ cores. As reflected …

Assessment For Sustainable Transportation Systems In Egypt, Hagar Mohamed Fares

Theses and Dissertations

The assessment of a sustainable transportation system poses a significant challenge for local governments, as it dramatically influences the promotion of environmentally friendly modes of transportation with the objective of safeguarding the public's welfare and health in their daily activities. The integration of such assessment should be implemented from the initial stages of system planning to its operational and maintenance phases, particularly in light of the increasing number of urban development activities nationwide. In order to facilitate decision-making processes, it is imperative to establish an efficient rating system that incorporates cultural and social constraints and comprehensively considers the three dimensions …

Cost Modeling Of Provision C.3 Green Stormwater Infrastructure Requirements For Residential Development In Concord, California, James Henry Mizutani

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

To assist the city of Concord in achieving its housing goals as presented in its general plan, while still meeting the stormwater discharge requirements laid out in the city’s municipal discharge permit, I worked with local developers and consultants to create a spreadsheet modeling tool that allows housing developers to estimate the total cost of green stormwater infrastructure needed to comply with local regulations.

This report contains a summary of the conditions leading to the necessity of this tool, the steps the tool takes that go beyond existing models, a description of how the model operates, instructions on how to …

Fabrication Of A Low-Cost Drum Seeder For Paddy, Muhammad Rashed Al Mamun, Md Rejaul Karim, Md Towfiqur Rahman, Md Janibul Alam Soeb, Md Imranul Alam

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rice is a staple food crop. Bangladesh produces it extensively which raised the nation into the fourth-largest rice-grower in the world. Transplanting or direct seeding is a major task in rice cultivation where the manual transplanting method requires a huge labor cost which is beyond control in a peak season. Although mechanical rice transplanters become popularization land preparation and seedling rising as a pre transplanting task is costly and labor-intensive. On the other hand, manual broadcasting and machine seeding direct method still exist due to the above method’s problem. Considering spacing accuracies for intercultural operation, drum seeders are an easy …

Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson

Honors Theses

The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a …

Effect Of Waste Covid-19 Masks On Compaction Characteristics Of Silty-Clay Soil, Sydney K. Lawson

Honors College Theses

The present study aims to explore the effect of adding shredded waste Covid-19 masks to silty-clay soil on the soil’s compaction characteristics for beneficial use in embankment, the subgrade of roadways, or backfill. This was accomplished by using two different types of masks: blue surgical masks and KN95 masks. Both mask types were hand shredded into half-inch sections using safety-scissors. The maximum dry density (MDD) and optimum moisture content (OMC) are the two most important compaction characteristics, and they were determined by the Standard Proctor Compaction Test (ASTM D698 / AASHTO T99). The change of both the MDD and OMC …