Mechanical Behavior Of Composite Structures Of Wearing Course And Underlying Layer For Asphalt Pavements,
2024
China Railway Construction Investment Group Corporation Limited ， Zhuhai ， Guangdong 519000 ， China
Mechanical Behavior Of Composite Structures Of Wearing Course And Underlying Layer For Asphalt Pavements, Yang Xiaohua, Yuan Zhanwen, Wen Yongbing, Zhou Chao, Wu Hao
Journal of China & Foreign Highway
The interlayer bonding state of pavement structures changes due to the influence of various factors under service conditions，and this change exhibits a significant influence on the mechanical behavior of pavement structures.Through the composite structure test and numerical analysis，the mechanical behavior of the composite structure of different wearing courses and underlying layers under different stresses and bonding states was studied.The test used three commonly used wearing course （surface layer ） materials of asphalt pavements，namely AC- 13，OGFC- 13，and SMA- 13 for comparative analysis.The test results show that different composite structures exhibit different interlayer bonding properties and fatigue characteristics due to the difference …
Shear Strength Test Of Hefei Expansive Soil Under Low Stress Conditions With Controlled Suction,
2024
School of Automotive and Transportation Engineering ， Hefei University of Technology ， Hefei ， Anhui 230009 ， China
Shear Strength Test Of Hefei Expansive Soil Under Low Stress Conditions With Controlled Suction, Hou Chaoqun, Zhang Rongjian, Li Yongxin
Journal of China & Foreign Highway
Topsoil slide and instability of expansive soil slopes may occur under variable saturation conditions.In order to study the strength characteristics of unsaturated expansive soil under low stress conditions，several different matrix suction and stress conditions were set by unsaturated triaxial apparatus.The triaxial shear test of Hefei expansive soil was carried out，and the test data were analyzed.The test results show that when the net confining stress on the expansive soil continues to weaken，the stress-strain curve transitions from strain hardening to strain softening.The strength of unsaturated expansive soil increases with increasing matrix suction.The shear strength of shallow expansive soil shows a significant reduction …
Comparative Analysis Of Test Results Of Different Nano‑Clay Improved Loess,
2024
School of Highway ， Chang'an University ， Xi'an ， Shaanxi 710064 ， China
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 …
Influence Of Rap Content On Mechanical Properties And Pavement Performance Of Warm Recycled Asphalt Mixture,
2024
School of Transportation Engineering ， Shandong Jianzhu University ， Jinan ， Shandong 250101 ， China
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 …
Different Forms Of Nano‑Sio2 In Emulsified Asphalt And Their Effects On Emulsion Storage Stability,
2024
Sixth Engineering Branch of CCCC Fourth Highway Engineering Co .， Ltd.， Tianjin 301700 ， China
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,
2024
Research Institute of Highway Ministry of Transport ， Beijing 100088 ， China ;Key Laboratory of Transport Industry of Road Structure and Material ， Beijing 100088 ， China
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,
2024
Jinhua Highway and Transportation Management Center ， Jinhua ， Zhejiang 321000 ， China
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 …
Effect Evaluation Method Of Foamed Asphalt Based On Digital Image Processing Technology,
2024
Shanxi Transportation Research Institute Group Co .， Ltd.， Taiyuan ， Shanxi 030000 ， China ;Shanxi Transportation Technology Research & Development Co .， Ltd.， Taiyuan ， Shanxi 030000 ， China
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 …
Study On Flexural Behavior Of Wet Joints Of Prefabricated Steel‑Uhpc Composite Bridge Deck,
2024
Key Laboratory for Wind and Bridge Engineering of Hunan Province ， School of Civil Engineering ， Hunan University ， Changsha ， Hunan 410082 ， China
Study On Flexural Behavior Of Wet Joints Of Prefabricated Steel‑Uhpc Composite Bridge Deck, Liao Wancheng, Zhao Hua, An Jiahe
Journal of China & Foreign Highway
Prefabricated steel-UHPC composite bridge deck is a new deck structure system that places the longitudinal rib at the upper layer and forms PBL shear connectors.This structure can be prefabricated in the factory and assembled on-site.The adjacent steel beams are integrated by welding，and the cast in-situ UHPC wet joints connect the adjacent UHPC bridge decks.However，these wet joints represent the structure's vulnerable segments but with little research.To this end，a full-scale model test has been conducted to study the flexural behavior of the wet joints in a steel-UHPC composite bridge deck in a practical project.The Abaqus finite element model was established and verified …
Deflection Variation Rule Of Main Girder For A Concrete Cable‑Stayed Bridge Based On Combined Static And Dynamic Modification,
2024
School of Civil Engineering ， Southwest Jiaotong University ， Chengdu ， Sichuan 610031 ，China ;National Engineering and Research Center for Mountainous Highways ， Chongqing 400000 ， China
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 …
Influence Of Aerodynamic Shape Change On Wind Resistance Performance Of Large Span Truss Bridge,
2024
Lhasa Municipality Design Group Co .， Ltd.， Lhasa ， Xizang 850000 ， China ;Wind Engineering Key Laboratory of Sichuan Province ， Southwest Jiaoto ng University ， Chengdu ， Sichuan 610031 ， China
Influence Of Aerodynamic Shape Change On Wind Resistance Performance Of Large Span Truss Bridge, Jing Dade, Su Yi
Journal of China & Foreign Highway
The development of the transportation an d tourism industry has led to bridges fulfilling additional roles，such as tourism，alongside their transportation functions，resulting in significant changes in structural aerodynamic shape and ventilation rate.This paper analyzed a double-tower single-span steel truss suspension bridge with a main span of 1 088 m，re-evaluated its wind resistance performance through the full-bridge aeroelastic model wind tunnel test，and evaluated the pedestrian comfort problem while studying the wind-resistant stability of the structure.The results indicate that the structural dynamic characteristics of the bridge remain almost unchanged before and after altering the aerodynamic shape of the bridge for its scenic spot …
Influence Of Section Selection On Mechanical Performance Of Corrugated Steel Box Culvert,
2024
School of Civil Engineering ， Beijing Jiaotong University ， Beijing 100044 ， China ;Shandong Provincial Communications Planning and Design Institute Group Co .， Ltd.， Jinan ， Shandong 250031 ， China
Influence Of Section Selection On Mechanical Performance Of Corrugated Steel Box Culvert, Zhang Shun, Liu Baodong, Gao Meng, Wu Fei, Wang Zhihong
Journal of China & Foreign Highway
Corrugated steel box culverts exhibit a higher section utilization rate compared with circular，arched，and pipe-arch corrugated steel structures，making them more suitable for for scenarios with restricted embankment height.While numerous studies focus on strengthening strategies for corrugated steel box culverts，research on selecting cross-sectional forms is scarce.This study utilized the finite element analysis software Abaqus to develop finite element models of corrugated steel box culverts with sidewall inclination angles of 0°，5°，10°，15° and 20° respectively.The impact of these inclination angles on the structural stress and deformation outcomes was analyzed.The results indicate that increasing the sidewall inclination angles can effectively reduce vertical deformation and maximum …
Study On Anchorage Reliability For Strand Shoe And Pull Rod Of Air‑Spinning Suspension Bridge,
2024
Deyang Tengen Heavy Industry Co .， Ltd.， Deyang ， Sichuan 618000 ， China
Study On Anchorage Reliability For Strand Shoe And Pull Rod Of Air‑Spinning Suspension Bridge, Huang Anming, Yang Bo, Chen Long, Xie Jun, Chen Xin
Journal of China & Foreign Highway
Each strand wire of the main cable in the suspension bridge constructed by the AS method is sleeved and anchored on the strand shoes on both banks.The strand shoe transmits the strand force to the anchoring system through the pull rod.The bearing capacity of the strand shoe after the interaction between the strand shoe and the wires of the main cable，the stress state of the wires after small curvature bending，and the influence of installation accuracy of the pull rod on the anchoring reliability all need to be qualitatively and quantitatively studied and verified by the experiment.In this paper，the main cable …
Construction Technology Of Reactive Powder Concrete Prestressed Box Girder,
2024
China Railway Urban Construction Group Corporation Limited ， Changsha ， Hunan 410208 ， China
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.
Key Construction Techniques For Incremental Launching And High Falling Beam Of Long‑Span Simply Supported Steel Box Girder,
2024
Mechanization Engineering Co .， Ltd.， China Railway No . 5 Engineering Group Co .， Ltd.， Hengyang ， Hunan 421000 ， China
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 …
Research On Gravity Anchorage Foundation Of Dadu River Bridge In Luding,
2024
Sichuan Highway Planning Survey Design and Research Institute Ltd .， Chengdu ， Sichuan 610041 ，China
Research On Gravity Anchorage Foundation Of Dadu River Bridge In Luding, Zhou Ti Ng, Tao Qiyu, Li Zejun
Journal of China & Foreign Highway
Moraine soils formed during th e Qua ternary glacial period are widely distributed in the west of China，exhibiting good mechanical properties and deep overburden.This paper studied the Dadu River bridge in Luding and investigated the influence of various foundation forms on anchorage stability in the case of considering moraine soils as the soil supporting layer of gravity anchorage foundation through theoretical analysis and numerical simulation.The findings suggest that a slant expanded foundation with a notched sill demonstrates good force-bearing capability and is cost-effective.These results can provide a reference for similar construction projects in the west of China.
Fragilit Y Analysis Of Continuous Rigid Frame Bridge With High Piers And Long Span Subjected To Near‑Field Earthquakes,
2024
Gansu Luqiao Highway Investment Co .， Ltd.， Lanzhou ， Gansu 730050 ， China
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 …
Prediction Method Of Surrounding Rock Deformation Of Highway Tunnels Based On Bayes‑Lstm,
2024
CCCC First Highway Consultants Co .， Ltd.， Xi'an ， Shaanxi 710076 ， China
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 …
Research On Shape Optimization Of Four‑Center Circular Highway Tunnel Based On Parametric Modeling Idea,
2024
CCCC Tunnel and Bridge （Nanjing ） Technology Co .， Ltd.， Nanjing ， Jiangsu 211800 ， China
Research On Shape Optimization Of Four‑Center Circular Highway Tunnel Based On Parametric Modeling Idea, Zhu Lei, Guo Meng, Guo Jinyong, Shen Caihua, Zhang Hanyi
Journal of China & Foreign Highway
The rational cross-sectional form of the four-center circular highway tunnel contributes to enhancing the stress state of the lining structure，reducing cracks in the composite lining，and enhancing the durability of the tunnel structure.Utilizing the Ansys APDL programming platform and guided by the design principle of continuous-curvature，a parametric modeling equation for the geometrical dimensions of local tunnel shape in arch foot area was established.The calculation method and numerical simulation models for the equivalent mechanical parameters of the anchor reinforcement area were also developed.The study revealed the impact of the local tunnel shape parameter design in the arch foot area on the internal …
Test On Water Mist Wrapped Dust Reduction Technology For Tunnels,
2024
CCCC Second Highway Engineering Co .， Ltd， Xi'an ， Shaanxi 710065 ， China
Test On Water Mist Wrapped Dust Reduction Technology For Tunnels, Wang Yijun, Wang Fei, Jia Yuedi, Pan Weihua, He Xingchun, Yao Wenhui
Journal of China & Foreign Highway
In order to eliminate the dust produced by tunnel blasting more quickly and effectively，two kinds of mist spray and dust reduction schemes were put forward，which were the “air duct water mist wrapped type ” and the “vehicle-mounted water mist wrapped type ”.The field test was carried out on Jiaoding Tunnel in Yunnan.The results show that for the dust reduction technology scheme of “air duct water mist wrapped type ”，the dust concentration of the No.1 characteristic position at the tunnel face decreases to 3.87 mg/m3 after 10 minutes of dust reduction，which meets the specification requirements.For the dust reduction technology of “vehicle-mounted …
