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Articles 211 - 240 of 674

Full-Text Articles in Materials Science and Engineering

Overall Design Concept Of Municipal Reconstruction Of Cross‑City Expressway, Fu Yuankun, Zhang Yu Oct 2024

Overall Design Concept Of Municipal Reconstruction Of Cross‑City Expressway, Fu Yuankun, Zhang Yu

Journal of China & Foreign Highway

The municipal reconstruction of the cross-city expressway is of great significance in enlarging the urban framework,refining the spatial pattern,and promoting the integrated development of clusters.However,China’s expressways seldom undergo municipal reconstruction,with less synergy formed with cities.Therefore,taking one case described above in Hebei Province as an example,this article proposed the overall design concept of integrating with the city from urban space,road networks,municipal facilities,urban ecology,cultural landscape,and other perspectives after analyzing problems in urban space,traffic,industry,landscape and urban quality in existing cross-city expressways. In addition,this paper studied and optimized the municipal reconstruction plan.Holding a theme of “municipalization ”,the plan eliminated the fragmentation of urban space …


Progress And Prospects Of Road Engineering Disease Treatment Technology In Permafrost Regions, Gao Feng, Zeng Xianzhang, Zhong Wenhua, Huang Shengyong, Zhang Junhui Oct 2024

Progress And Prospects Of Road Engineering Disease Treatment Technology In Permafrost Regions, Gao Feng, Zeng Xianzhang, Zhong Wenhua, Huang Shengyong, Zhang Junhui

Journal of China & Foreign Highway

Freeze-thaw disasters are key issues affecting the service performance and operational safety of road projects in permafrost regions.Under the combined influence of warming and humidification of the permafrost environment and engineering thermal effects,the degradation of permafrost is accelerating,exacerbating the risk of road freeze-thaw diseases.Roads in these regions are more frequently maintained and repaired to ensure service performance,with a service life lower than designed.Therefore,deepening the understanding of the disaster mechanism of road geotechnical structures and strengthening the study on engineering disease treatment technology are of great significance in promoting the construction and maintenance of high-quality and high-grade highways in frozen regions.This …


Model Test On Soil Deformation Mechanism And Damage Mode Caused By Mud Leakage From Drilled Piles In Karst Area, Jiang Mingying, Chen E ’Mei, Liu Yongcheng, Zhu Yadong, Jiang Wenkui, Xie Ruiting Oct 2024

Model Test On Soil Deformation Mechanism And Damage Mode Caused By Mud Leakage From Drilled Piles In Karst Area, Jiang Mingying, Chen E ’Mei, Liu Yongcheng, Zhu Yadong, Jiang Wenkui, Xie Ruiting

Journal of China & Foreign Highway

Pile holes are often drilled through cavities in karst areas,which induces mud leakage and causes hole wall instability,ground collapse,or equipment trapping and hinders smooth construction.It is important to know the collapse mechanism of boreholes due to mud leakage,so as to optimize and determine the construction process of pile holes.In this paper,indoor model tests were used to study the deformation mechanism and damage mode of soil caused by drilling through cavities and mud leakage in pile holes under the conditions of upper clay and lower sandy soil in the karst area,so as to provide an experimental basis for the decision of …


Deformation Measurement And Safety Warning Of Highway Bridges Based On Machine Vision, Su Ziyue, Du Wenkang, Lei Dong Oct 2024

Deformation Measurement And Safety Warning Of Highway Bridges Based On Machine Vision, Su Ziyue, Du Wenkang, Lei Dong

Journal of China & Foreign Highway

The structural safety of highway bridges plays a crucial role in traffic safety operations and regional economic development.Due to the rapid increase and complex changes in traffic loads,the demand for real-time monitoring of bridge ’s structural deformation and safety conditions has been increasingly prominent.However,the structural health monitoring system,dominated by contact sensors,has limitations such as difficult installation and construction,complicated maintenance and replacement,and the need to interrupt traffic.To this end,a non-contact deformation measurement system based on machine vision was proposed.Template matching and feature point recognition methods were utilized to achieve recognition of structural surface markings and displacement extraction of key positions.The accuracy …


Properties And Application Of Cement Improved Loess Under Low Temperature Environment In Cold Region, Li Xiangyang Oct 2024

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

Journal of China & Foreign Highway

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


Effect Of Chloride Ions On Salt Expansion Of Salinized Subgrade Fill Soil In Cold Regions, Hu Wenzhu, Wang Zhaowei, Cao Yong, Zhang Jing, Bai Ruiqiang Oct 2024

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

Journal of China & Foreign Highway

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


Correlation Between Pavement Distress And Structural Hidden Distress, Liu Xianming, Xia Han, Hu Dongping, Yan Chen, Yang Rui, Zhong Xinran Oct 2024

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

Journal of China & Foreign Highway

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


Structural Repair And Performance Evaluation Of Aged Sbs Modified Asphalt, Xu Guang, Li Qishi, Kuang Huaping, Zhang Henglong, Zhou Ruibo, Chen Yanmei Oct 2024

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

Journal of China & Foreign Highway

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


Vessel Collision Force And Anti‑Collision Performance Of Long‑Span Beam‑Arch Composite Rigid Frame Bridge, Zhang Wenming, Wang Zhiwei, Lai Yaping Oct 2024

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

Journal of China & Foreign Highway

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


Installation And Connection Mode Of Stiffening Beam Segment Of Steel Truss Suspension Bridge, Chen Changsong, Wu Junjie Oct 2024

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

Journal of China & Foreign Highway

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


Seismic Responses Of Cable‑Sta Yed Bridge Considering Ponding Effect Under Near‑Fa Ult Ground Motions, Lyu Long, Yu Deen, Yuan Yuhang, Yang Huaiyu Oct 2024

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

Journal of China & Foreign Highway

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


Multi‑Dimensional And Multi‑Point Random Seismic Response Analysis Of Long‑Span Cable‑Stayed Bridges At Different Sites, Shi Yi, Lu Lu, Fan Shuli, Shen Meng, Zuo Chunyuan, Sun Xinguo, Cao Feifei Oct 2024

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

Journal of China & Foreign Highway

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


Rigid Domain Optimization Of Steel Truss Joint With Reference To Multi‑Scale Model, Liu Gaocheng, Liu Jian, Dong Chuangwen, Li Chuanxi Oct 2024

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

Journal of China & Foreign Highway

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


Impact Resistance Of Ecc Pipe Piles Based On Ls‑Dyna, Zeng Qingyou, Ye Chenfeng, Liu Junjun, Feng Kai, Cheng Peiyuan, Chen Weihong Oct 2024

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

Journal of China & Foreign Highway

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


Comparative Study Of Different Ventilation Methods During Tunnel Construction, Yue Kun, Bao Xiaohua, Ao Xiang, Liu Kuan, Wu Han, Li Tao, Shen Jun Oct 2024

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

Journal of China & Foreign Highway

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


Stability Of Excavation Face Of Double‑Mode Shield In Earth Pressure Mode Crossing Fault Zone Of Pearl River, Tong Bin, Zhang Bin, Zhu Hanbiao, Wang Shuying Oct 2024

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

Journal of China & Foreign Highway

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


Development Trend On Raw Materials Market Of Ready‑Mixed Concrete Under Green Construction, Ding Hu, Ding Qingjun, Lin Haojun, Zhang Zhen Oct 2024

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

Journal of China & Foreign Highway

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


Review Of Snow And Ice Melting Techniques For Road And Bridge In Cold Regions, Tang Liyun, Shao Haitao, Tang Huaming, Qiu Peiyong, Du Xiaoqi, Zhang Lei, Peng Hui Oct 2024

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

Journal of China & Foreign Highway

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


Post‑Evaluation Method For Decision‑Making And Implementation Of Highway Maintenance Projects Based On Ahp‑Dematel, Yu Wei, Yang Na, Li Jue Oct 2024

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

Journal of China & Foreign Highway

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


Concrete Design: Underwater Concrete Forms In A Saltwater Environment, Noah Z. Lau Oct 2024

Concrete Design: Underwater Concrete Forms In A Saltwater Environment, Noah Z. Lau

Construction Management

This following project investigated the effects of salt on the concrete curing process. Concrete possesses numerous strengths, making it extremely versatile. This makes it one of the most utilized construction materials. New improved methods are constantly being developed for concrete’s application as a construction material. While concrete is a flexible material with many strengths, it is not without its flaws. Concrete, while strong in compression is weak in tension. It has long cure times and doesn’t generally handle moisture well. This paper evaluates concrete’s change in strength from letting concrete cure in a salt-based underwater environment. To determine the full …


Effect Of Aging Temperature On Properties Of Sealant Under Field Construction Conditions, Liu Hanchao, Teng Xinhua, Zhang Jingyan, Zhang Kaihua, Lin Hui Jul 2024

Effect Of Aging Temperature On Properties Of Sealant Under Field Construction Conditions, Liu Hanchao, Teng Xinhua, Zhang Jingyan, Zhang Kaihua, Lin Hui

Journal of China & Foreign Highway

In order to study the influence of short-term aging temperature on the properties of sealant,a sealant was prepared,and field construction conditions were simulated.The properties of the sealant before and after short-term aging at 180‒220 ℃ were tested.The viscoelastic properties,physicochemical properties,and microstructures of the sealant were studied,and the mechanism of property changes was discussed.The results show that the cone penetration and flow value of the aged sealant decrease,while the softening point and elastic recovery rate increase.Aging at high temperature (>180 ℃) for a short time and low temperature (160 ℃) for a long time will cause obvious property changes.The tensile …


Experimental Study On Capillary Water‑Holding Characteristics Of Loess Backfill In Ecological Ditches, Nan Yalin, Zhang Xiaoyu, Chen Hong, An Peng, Liu Kui, Camara Ibrahima Kalil Jul 2024

Experimental Study On Capillary Water‑Holding Characteristics Of Loess Backfill In Ecological Ditches, Nan Yalin, Zhang Xiaoyu, Chen Hong, An Peng, Liu Kui, Camara Ibrahima Kalil

Journal of China & Foreign Highway

The municipal ecological ditches have the basic functions of accumulating water for infiltration in the rainy season and conserving moisture in the dry season.However,the design of loess backfill in ecological ditches is based on no evidence,which often leads to landscape vegetation drowning in the rainy season or dying in the dry season.For this reason,a study was carried out by remoulding loess with a small-size capillary water rise height test,a large-size water-holding characteristic model test,and an unsaturated numerical analysis.The results show that the final capillary water rise height of the soil column can reach 100 cm when the dry density is …


Research On Performance Of Coal Gangue Concrete, Wang Jiliang, Ma Wenhui, Xu Weidong, Lyu Zhigang Jul 2024

Research On Performance Of Coal Gangue Concrete, Wang Jiliang, Ma Wenhui, Xu Weidong, Lyu Zhigang

Journal of China & Foreign Highway

Coal gangue is an industrial solid waste produced in the process of raw coal mining.It has a large stock and a relatively low utilization rate.Using coal gangue as concrete aggregate can not only solve the environmental pollution caused by coal gangue storage but also make up for the shortage of natural sand and gravel resources,which opens up an effective way for the large-scale utilization of coal gangue.According to the application characteristics of coal gangue as concrete aggregate,the chemical component,mineral composition,and physical properties of coal gangue were systematically analyzed.The influence of coal gangue as aggregate on the working performance,mechanical properties,volume stability,and …


Experimental Study On Shear Performance Of Uhpc‑Nc Interface, Wan Zhiyong, Chen Jianping, He Shaohua, Huang Xu, Sun Xiangdong Jul 2024

Experimental Study On Shear Performance Of Uhpc‑Nc Interface, Wan Zhiyong, Chen Jianping, He Shaohua, Huang Xu, Sun Xiangdong

Journal of China & Foreign Highway

Ultra-high performance concrete (UHPC) has great application prospects in engineering structure reinforcement.The reliability of the bonding properties at the interface between the new UHPC reinforcement layer and the old concrete structure is critical for ensuring the serviceability of the reinforced structures.To determine the influence of different interface treatments on the bonding properties at the interface between the UHPC and normal concrete (NC),six Z-shaped UHPC-NC bonding specimens were designed,and the bonding properties of the UHPC-NC with three different kinds of interface,namely smooth,chisel,chisel + reinforced,were investigated.In addition,nonlinear finite element models for the concrete interface were established to determine the distribution law of …


Application Of Sequential Quadratic Programming Method In Cable Force Adjustment Of Cable‑Stayed Bridges, Xu Yufeng, Zhu Mengyang, Chen Si, Xie Yunfei Jul 2024

Application Of Sequential Quadratic Programming Method In Cable Force Adjustment Of Cable‑Stayed Bridges, Xu Yufeng, Zhu Mengyang, Chen Si, Xie Yunfei

Journal of China & Foreign Highway

When the construction of a cable-stayed bridge enters the completion stage,due to various factors,there is a certain error between the actual alignment and internal force of the structure and the theoretical completion state,and it is usually necessary to adjust the cable force.In order to calculate the cable force adjustment of a cable-stayed bridge in the adjustment stage,a method based on an influence matrix and sequential quadratic programming was proposed to solve the cable force adjustment.A large-span hybrid girder cable-stayed bridge was taken as the background,and the alignment and internal force response values of the structure with varying cable units were …


Protection Design Of Middle Piers Of Overpass Bridges Based On Double Protection Concept, Lyu Sizhong, Wang Xin, Guo Jianmin, Liu Siyuan, Li Yuxin, Yang Fuyu Jul 2024

Protection Design Of Middle Piers Of Overpass Bridges Based On Double Protection Concept, Lyu Sizhong, Wang Xin, Guo Jianmin, Liu Siyuan, Li Yuxin, Yang Fuyu

Journal of China & Foreign Highway

The collision accident types of middle piers of overpass bridges were summarized and analyzed,and it was proven that anti-collision and anti-scratching were two important requirements of pier protection.Then,the new concept of double protection and corresponding technical schemes were put forward.The first protection adopted the way of setting concrete barriers or ship-shaped elevating members on the periphery of the pier to prevent vehicles from impacting the pier,and the second protection used the self-wrapped steel plate or aluminum foam plate to prevent vehicles from scratching the pier.The safety of the pier protection structure schemes was verified by computer simulation and unit test,and …


Research On Yolov 5‑Ganomaly Joint Algorithm For High‑Strength Bolt Detection, Xie Haibo, Zhu Weijun, Zhang Bi2, Zhang Dahai Jul 2024

Research On Yolov 5‑Ganomaly Joint Algorithm For High‑Strength Bolt Detection, Xie Haibo, Zhu Weijun, Zhang Bi2, Zhang Dahai

Journal of China & Foreign Highway

High-strength bolt loosening detection of bridges faces problems such as heavy workload,small targets,many anomalies,and difficult collection.Therefore,this paper proposed a semi-supervised deep learning model,which could obtain the bolt loosening detection model even with a small number of negative samples and solve the problem of unbalanced model training samples.The accuracy of the YOLOv 5-CT model for bolt target detection reached 98.33%.By preprocessing bolt data,the reconstruction ability of bolt images by the Ganomaly model was improved.When the hidden space vector value was 100,the model had the highest SAUC and the best discriminant performance.In the model test stage,the threshold of abnormal fraction was set …


Experimental Study On Effect Of Temperature On Bound Water Adsorption And Deformation Of High Liquid Limit Soil, Zi Yinhui, Shen Xuning, Zhang Hao, Zhang Rui, Li Lu Jul 2024

Experimental Study On Effect Of Temperature On Bound Water Adsorption And Deformation Of High Liquid Limit Soil, Zi Yinhui, Shen Xuning, Zhang Hao, Zhang Rui, Li Lu

Journal of China & Foreign Highway

In order to study the effect of temperature change on the bound water content adsorbed by high liquid limit clay and the deformation law of high liquid limit clay embankment,the high liquid limit clay in Hainan Province was selected as the primary research object and compared with the low liquid limit sand in Hunan Province.The effect of temperature on the bound water content adsorbed by high liquid limit clay was explored through a nuclear magnetic resonance test.In addition,the effect of temperature on the deformation of high liquid limit clay embankments was analyzed through the consolidation test with a temperature-controlled consolidometer.The …


Temperature And Strain Development Characteristics Of Tunnel Concrete Based On Double Grating Sensors, Fang Jianping, Zhang Mengxi, Yao Xiaonan Jul 2024

Temperature And Strain Development Characteristics Of Tunnel Concrete Based On Double Grating Sensors, Fang Jianping, Zhang Mengxi, Yao Xiaonan

Journal of China & Foreign Highway

In order to better prevent tunnel concrete from cracking,the development law of concrete temperature and strain was studied.Based on the connection project of Sanjiang Middle Road in the Smart New City of Quzhou,a data acquisition system was established to monitor concrete temperature and strain on site.The defects of the traditional method that the temperature and strain monitoring are insensitive,and the monitoring data is discontinuous were overcome.In addition,the high-performance double grating temperature-strain sensor was used to simultaneously monitor the temperature and strain at the same position,and the temperature compensation method was used to overcome the influence of the ambient temperature on …


Properties And Mechanism Of Reclaimed Asphalt Based On Sbs Structure Repair, Feng Xinjun, Yang Hongyang, Xiao Honghai, Zhu Ziqiang Jul 2024

Properties And Mechanism Of Reclaimed Asphalt Based On Sbs Structure Repair, Feng Xinjun, Yang Hongyang, Xiao Honghai, Zhu Ziqiang

Journal of China & Foreign Highway

At present,the common asphalt regenerant is used for treating the aged styrene-butadiene-styrene (SBS) modified asphalt in China,which fails to repair the SBS cross-networking structure,resulting in the poor regeneration effect of the aged SBS modified asphalt.In this study,a new reactive regenerator containing a structural repair agent,extractive oil,plasticizer,solubilizer,and a small amount of SBS was used to regenerate the aged SBS modified asphalt.The conventional properties and rheological properties of reclaimed SBS modified asphalt were studied by three index tests,Brookfield viscosity test,dynamic shear rheological test,and low temperature bending rheological test.Then,a fluorescence microscope and infrared spectrometer were used to study the regeneration mechanism of the …