The boundary layer is a buffer layer of water and heat exchange between the atmosphere and permafrost. Based on the atmospheric boundary layer and heat transfer theory, we established a method for determining the boun...The boundary layer is a buffer layer of water and heat exchange between the atmosphere and permafrost. Based on the atmospheric boundary layer and heat transfer theory, we established a method for determining the boundary layer thickness of engineering pavement （asphalt and sand pavement） in permafrost region. The boundary layer can be divided into the Boundary Layer Above Surface （BLAS） and the Boundary Layer Below Surface （BLBS）. From in-situ monitoring data, the thickness of BLAS was determined through the laminar thickness, and the thickness of BLBS was determined through ground temperature, the heat conduction function, and the mean attenuation function （α）. For asphalt pavement, the BLAS thickness varied between 2.90 and 4.31 mm and that of BLBS varied between 28.00 and 45.38 cm. For sand pavement, the BLAS thickness varied between 2.55 and 3.29 mm and that of BLBS varied between 15.00 and 46.44 cm. The thickness varied with freezing and thawing processes. The boundary layer calculation method described in this paper can provide a relatively stable boundary for temperature field analysis.展开更多
Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pave...Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.展开更多
为有效延长城市快速公交系统(BRT)站台铺装层的使用寿命并提升正交异性钢桥面板的抗疲劳性能,同时满足不中断交通的需求,提出了“正交异性钢桥面板+短剪力钉+预制超高性能混凝土(UHPC)板+TPO(薄层环氧抗滑铺装材料)”的复合桥面结构及...为有效延长城市快速公交系统(BRT)站台铺装层的使用寿命并提升正交异性钢桥面板的抗疲劳性能,同时满足不中断交通的需求,提出了“正交异性钢桥面板+短剪力钉+预制超高性能混凝土(UHPC)板+TPO(薄层环氧抗滑铺装材料)”的复合桥面结构及装配化施工工艺。以成都二环线高架桥BRT站台为工程背景,设计了BRT站台铺装层快速维修方案,通过有限元分析确定了最优方案,并开展了BRT站台钢桥面维修改造试验段的实施。有限元分析结果表明:10 mm UHPC灌浆料+50 mm预制UHPC板+10 mm TPO为最佳方案,维修方案的剪力钉受力性能、UHPC抗裂性能均满足结构受力需求,且具有较大的安全储备,改造后正交异性钢桥面板常见疲劳敏感细节的疲劳性能显著提升。结合试验段实施提出了涵盖UHPC板预制、原铺装层处理、预制UHPC板安装和磨耗层与沥青接缝施工4个流程的城市BRT站台铺装层维修施工工艺,为同类型公交站台铺装层维护提供了理论和技术支撑。展开更多
基金supported by the Natural Science Foundation of China (41330634 and 41301071)the Independent Research Project of State Key Laboratory of Frozen Soil Engineering (SKLFSE-ZQ-19)
文摘The boundary layer is a buffer layer of water and heat exchange between the atmosphere and permafrost. Based on the atmospheric boundary layer and heat transfer theory, we established a method for determining the boundary layer thickness of engineering pavement （asphalt and sand pavement） in permafrost region. The boundary layer can be divided into the Boundary Layer Above Surface （BLAS） and the Boundary Layer Below Surface （BLBS）. From in-situ monitoring data, the thickness of BLAS was determined through the laminar thickness, and the thickness of BLBS was determined through ground temperature, the heat conduction function, and the mean attenuation function （α）. For asphalt pavement, the BLAS thickness varied between 2.90 and 4.31 mm and that of BLBS varied between 28.00 and 45.38 cm. For sand pavement, the BLAS thickness varied between 2.55 and 3.29 mm and that of BLBS varied between 15.00 and 46.44 cm. The thickness varied with freezing and thawing processes. The boundary layer calculation method described in this paper can provide a relatively stable boundary for temperature field analysis.
文摘Asphalt pavement is currently one of the main components in the construction of roads and bridges.However,from a practical point of view,various quality problems are prone to occur in the surface layer of asphalt pavement,which will lead to the poor overall quality of road and bridge projects.Therefore,it should be applied reasonably.Advanced testing technologies are used to test the mixture quality,compaction,segregation,thickness,and other aspects of the asphalt pavement surface layer,so as to improve the quality of the asphalt pavement surface layer,and then improve the overall quality of road and bridge construction.Therefore,this paper mainly analyzes the technologies for asphalt pavement surface layer testing in road and bridge engineering construction.
文摘为有效延长城市快速公交系统(BRT)站台铺装层的使用寿命并提升正交异性钢桥面板的抗疲劳性能,同时满足不中断交通的需求,提出了“正交异性钢桥面板+短剪力钉+预制超高性能混凝土(UHPC)板+TPO(薄层环氧抗滑铺装材料)”的复合桥面结构及装配化施工工艺。以成都二环线高架桥BRT站台为工程背景,设计了BRT站台铺装层快速维修方案,通过有限元分析确定了最优方案,并开展了BRT站台钢桥面维修改造试验段的实施。有限元分析结果表明:10 mm UHPC灌浆料+50 mm预制UHPC板+10 mm TPO为最佳方案,维修方案的剪力钉受力性能、UHPC抗裂性能均满足结构受力需求,且具有较大的安全储备,改造后正交异性钢桥面板常见疲劳敏感细节的疲劳性能显著提升。结合试验段实施提出了涵盖UHPC板预制、原铺装层处理、预制UHPC板安装和磨耗层与沥青接缝施工4个流程的城市BRT站台铺装层维修施工工艺,为同类型公交站台铺装层维护提供了理论和技术支撑。
