(72+128+72)m预应力混凝土连续梁平面转动体系结构设计研究

The Design of a Horizontal Rotation System for a(72+128+72)m Continuous Pre-Stressed Concrete Beam Bridge

京雄城际铁路固安段上跨廊涿高速公路,为减少对营运高速公路的干扰,保障施工安全,降低施工风险,设计采用(72+128+72)m预应力混凝土连续梁桥支架现浇后平面转体施工方法。结合转体工程实际,在介绍全新的转体系统——下滑道连续牵引不平衡转体体系的基础上,系统的阐述了该系统临时支撑、环形滑道、连续牵引和导向系统的构造。工程应用表明此系统具有简化施工工艺、降低施工风险、节约工程造价、缩短工期等优势。

As the new(72+128+72)m continuous pre-stressed concrete beam bridge of the Gu'an Section of the Beijing-Xiong'an Intercity Railway has to span the Langfang-Zhuozhou Expressway,in order to reduce the disturbance of the construction to the normal operation of the expressway,ensure the security of the construction and lower construction risks,the construction method of first building the(72+128+72)m continuous pre-stressed concrete beam by means of casting-in-place with the help of scaffolds and supports,and then horizontally rotating it into place is designed and adopted.Upon the basis of considering the specific rotation construction conditions of the project,introduced first in the present paper is a totally new rotation system——the unbalanced rotation system of continuous traction of glide slope,upon the basis of which the composition and the structural design of the temporary supports,the circular slide,the continuous traction and the guide system of the rotation system are dealt with in the paper.Engineering practice shows that this horizontal rotation system has the advantages of being simple in construction processes,low in construction risks,economical in engineering costs and short in construction duration.