基于UHPC预制结构的BRT站台铺装层快速维修技术

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 mmUHPC灌浆料+50 mm预制UHPC板+10 mmTPO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。

Rapid Maintenance Technology of BRT Platform Pavement Layer Based on UHPC Prefabricated Structure

In order to effectively lengthen the service life of the platform pavement layer of urban bus rapid transit (BRT) and improve the anti-fatigue performance of orthotropic steel deck slab, and also to satisfy the need for the un-interruption traffic, the composite bridge deck structure and assembly construction technology of orthotropic steel deck + short shear studs + prefabricated ultra-high performance concrete (UHPC) slab + TPO (thin-layer epoxy anti-skid pavement material) is proposed. Taking the BRT platform of Chengdu 2nd Ring Line Viaduct as the engineering background, the rapid maintenance scheme of BRT platform pavement layer is designed. The optimal scheme is determined by the finite element analysis, and the experimental section of BRT platform steel bridge deck maintenance is carried out. The finite element analysis results show that the 10 mm UHPC grouting material+50 mm prefabricated UHPC slab+10 mm TPO is the best scheme. The mechanical properties of shear stud and the anti-cracking performance of UHPC in the maintenance scheme meet the structural mechanical requirements, and have a large safe reserve. After the reconstruction, the fatigue properties of common fatigue sensitive details of the orthotropic steel bridge deck are significantly improved. Combined with the implementation of the test section, the maintenance and construction technology of urban BRT platform pavement layer is proposed, which includes four processes of prefabrication of UHPC slab, treatment of original pavement layer, installation of prefabricated UHPC slab and construction of wear layer and asphalt joint, which provides the theoretical and technical supports for the maintenance of similar bus platform pavement layers.