Structural Design Issues of Accelerated Bridge Construction in Skew and Right Alignments

使用预制构件和系统来加速新桥的建设和更换老化的桥梁，最近已成为桥梁管理部门非常关注和感兴趣的主题。预制构件和系统可以快速组装，可以减少设计工作量，减少对场地附近环境的影响，并最大限度地减少延误和车道关闭时间以及对旅行公众的不便，节省时间和纳税人的钱。其中一种系统涉及全深度、全宽度、预制混凝土甲板板横向放置在钢或混凝土大梁上，其中提供灌浆袋以容纳焊接到钢梁或嵌入混凝土大梁中的剪切连接器集群。文献回顾揭示了一些重要的未解决的分析，设计和性能问题，需要详细的评估。这些问题包括：(1)预制桥面铺装过程中斜交非组合桥梁施工阶段的恒活荷载分配系数；（ii）斜交组合桥梁在极限和疲劳极限状态下的活载分配系数；（iii）与正桥相比，货车在斜桥上行驶时的动载余量（冲击系数）；（iv）结合玻璃纤维聚合物（GFRP）钢筋的横向预制板对板连接，其头端在桥跨内，以提高强度和耐久性；（vi）负弯矩区采用gfrp增强预制横向板对板连接，以提高组合梁在极限和疲劳极限状态下的抗弯强度。本研究的目的是通过开发实验校准的、基于计算机的设计指南，能够准确预测其在不同载荷下的响应，从而促进全深、全宽预制桥面板的有效设计，从而为桥梁所有者节省潜在的重大成本，并将其纳入CHBDC。现场数据和全面的实验结果将为桥梁设计师提供有意义的反馈，从而导致新一代的最低维护桥梁，详细说明了固有的耐久性。

The use of prefabricated elements and systems in accelerating construction of new bridges and replacement of deteriorated ones has recently been the subject of much attention and interest amongst bridge jurisdictions. Prefabricated elements and systems can be quickly assembled and could reduce design efforts, reduce the impact on the environment in the vicinity of the site, and minimize the delays and lane closure time and inconvenience to the traveling public, saving time and tax payers money. One of these systems involve full-depth, full width, precast concrete deck slab placed transversally over steel or concrete girders where grout pockets are provided to accommodate clusters of shear connectors welded to steel girders or embedded in concrete girders. Literature review revealed a number of important unresolved analysis, design and performance issues which require detailed evaluation. These issues include: (i) the dead and live load distribution coefficients for non-composite bridges in skew alignment at construction stage during precast deck placement; (ii) live load distribution coefficients for composite bridges in skew alignment at ultimate and fatigue limit states; (iii) the dynamic load allowance (impact factor) due to trucks moving over a skew bridge as compared to a right one; (iv) transverse precast panel-to-panel connection incorporating glass fibre polymer (GFRP) bars with headed ends within bridge span for strength and durability; and (vi) GFRP-reinforced precast transverse panel-to-panel connection at the negative moment region to increase flexural strength of the composite girder at ultimate and fatigue limit states. The aim of this research is to contribute to the efficient design of bridges built with full-depth, full-width, precast deck panels by developing experimentally-calibrated, computer-based, design guidelines capable of predicting accurately their response when subjected to different loading , with potentially significant cost savings to bridge owners and inclusion in CHBDC. Field data and full-scale experimental results will provide a meaningful feedback to bridge designers, leading to a new generation of minimal maintenance bridges, detailed for inherent durability.