摘  要：在借鉴钢与混凝土组合梁原理的基础上，结合沉井施工工艺，研究了钢梁作为钢模板结构和作为组合梁顶板结构一部分的全过程受力机理，提出了钢与混凝土组合梁板结构在沉井顶板结构中应用的技术方案，并以内净空跨度6 m的顶板结构为例，开展了组合梁板结构的优化设计。结果表明，与现浇结构相比，组合梁板结构的施工工期短，但在设计时应考虑防水、结构耐久性等问题；组合梁中钢梁的横向布置间距可从l0 /3处开始优化分析。

Abstract: Based on the principle of steel-concrete composite beam, combined with the construction technology of open caisson, the whole process stress mechanism of steel beam as steel formwork structure and as a part of composite beam roof structure was studied. The technical scheme of steel-concrete composite beam-slab structure applied in open caisson roof structure was put forward, and the roof structure with an internal clearance span of 6 m was taken as an example to optimize the design of the composite beam-slab structure. The results show that compared with the cast-in-place structure, the construction period of the composite beam-slab structure is shorter, but the problems such as waterproof and structural durability should be considered in the design. The optimal design of the transverse spacing of steel beams in composite beams can be started from l0 /3.