摘要
随着高速铁路建设的快速发展,大跨度预应力混凝土连续梁因其优越的承载能力和抗震性能广泛应用于铁路桥梁建设中。尤其是在复杂地形和高负载环境下,采用箱形截面的设计能够有效提升结构的稳定性。然而,0#块作为连续梁的中支点,其浇筑过程中的结构复杂性和钢筋密集性带来了诸多挑战。在混凝土浇筑过程中,0#块的下料难度较大,振捣棒无法直接到达需要振捣的区域,尤其是支座上方和腹板底部的钢筋密集区,易造成混凝土振捣不实,并可能出现蜂窝、孔洞和骨料堆积等缺陷,后期的整治与维修费用较高,运营后面临天窗内施工等不利因素。为此,本文依托某高铁工程,选取高铁预应力混凝土连续梁的0#块,采用多孔多点振捣施工工艺。通过BIM建模优化钢筋安装,并配合布料串筒、预留振捣通道和模板开窗等措施,有效预判风险点,为各部位混凝土的充分振捣提供了保障,从而较好地控制了施工质量。
With the rapid advancement of high-speed railway construction, large-span prestressed concrete continuous beams are extensively employed in railway bridge projects due to their exceptional load-bearing capacity and seismic performance. This is particularly important in complex terrain and high-load environments, where the use of box section designs can significantly enhance the structural stability. However, the construction of Block 0, positioned at the midpoint of the continuous beam, presents numerous challenges due to its structural complexity and the high density of steel reinforcement during the concrete pouring process. During the pouring operation, difficulty arises in effectively consolidating the concrete in Block 0, as conventional vibrators may not adequately reach areas requiring vibration, especially in densely packed regions of steel reinforcement located above the supports and at the base of the web plate. This often leads to inadequate compaction, resulting in defects such as honeycombing, voids, and aggregate segregation. The subsequent remediation and maintenance costs can be substantial, compounded by the challenges posed by working in limited spaces post-construction. Therefore, based on a high-speed railway project, this article selects the 0# block of prestressed concrete continuous beam for high-speed railway and adopts the construction technology of porous multi-point vibration. By optimizing the arrangement of steel reinforcement through Building Information Modeling (BIM), and integrating approaches such as fabric string tubes, reserved vibration channels, and formwork openings, potential risk points were effectively identified. These measures ensured comprehensive concrete vibration across all sections, thereby improving construction quality and reliability.
出处
《土木工程》
2025年第8期2074-2083,共10页
Hans Journal of Civil Engineering
