大跨度弦支混凝土梁施工过程监测与分析

MONITORING AND ANALYSIS OF CONSTRUCTION PROCESS OF LONG SPAN CONCRETE GIRDER WITH CHORD SUPPORT

某体育馆为大跨度弦支混凝土结构,其弦支混凝土梁由实腹型钢混凝土梁、预应力拉索和刚性撑杆组成,为减小拉索张拉引起的梁轴向变形,在梁的两端设置后浇带。并通过数值模拟,对比分析了模拟结果与实测结果。研究表明,大跨度弦支混凝土梁结构可大幅减小梁的截面尺寸,降低结构自重,增加室内净空高度;混凝土梁位移实测值与模拟值相近;预应力张拉完成后,混凝土梁产生的应力较小,说明采用的施工方法较为合理,相关研究成果可为类似工程提供参考。

One gymnasium of a middle school is a large-span concrete structure with chord support.The concrete girder with chord support is composed of solid-web steel reinforced concrete beams,prestressed cables and rigid braces. In order to reduce the axial deformation of the girder caused by the cable tension, post-casting belt is set at both ends of the girder. In the construction process,solid-web steel reinforced concrete beam was firstly completed. Then the cables were tensed after the concrete strength meets the requirements. Finally, post-casting belts were finished. In this paper, the construction process of concrete girder with chord support is introduced in detail, and the deformation and the stress were monitored. The simulation analysis of the structure is carried out, and the analysis values are compared with the measured values. The results show that the cross-section size and the dead load of the girder can be greatly reduced, and the indoor headroom height can be increased.The measured deformation of the concrete beam is close to the simulation result. After the prestressed tension, the stress of concrete beam is very little. It shows that the construction method is reasonable and the relevant research results can provide reference for similar projects.