大跨预应力超长结构无缝设计及控制研究

针对某横向35m跨、纵向120m超长结构的工程实例,合理运用纵横双向预应力技术,既解决了大跨度钢筋混凝土梁的强度变形要求,又解决了超长结构的纵向不设缝问题.本文通过对钢筋混凝土大跨超长结构的预应力和无缝设计技术要点的研究,提出了预应力裂缝控制设计与施工的控制参数,方法和一些技术措施,并在实际工程中通过现场测试得到了检验和应用.实验证明,本文提出的综合集成技术对多层大跨结构和超长结构裂缝控制是行之有效的,可适用于各种类型的大跨超长结构无缝设计的全过程控制.这对突破现行规范对不设缝结构长度的严格限制,为建筑创新创造自由空间具有很大应用价值.

Design and research on long-span prestress and extra-long seamless structure

Based on a real structure with 35m long span and 120m extra-long length, bidirectional prestress technique is organically adopted. Then it not only satisfies the requirement for the strength and deflection from the long span girders, but also resolves the difficulty on the treatment of longitudinally extra-long seamless structure. This paper focuses on its research on the key techniques acquired by the design and analysis of long prestressed girder and extra-long seamless structure. After that, a certain controlling parameters, design approach and measures taken are proposed for both design and construction. And all those have been verified and applied in a real project by means of field measurement. It has been practically proved that this comprehensive approach is valid to multi-storey long span structure and crack control on extra-long structure, and that it is applicable to the whole-process control on the design of long span, extra-long length structures. This definitely provides the architectual design with free creativity and high benefit without the restriction from the code that restrains the longitudinal length as being a seamless structural segment.