高速铁路先、后张预应力混凝土简支箱梁力学效应对比分析

Mechanics Effect Analysis of Pre-tensioned and Post-tensioned Pre-stressed Concrete Simply-supported Box Beams on High-speed Railway

通过有限元分析技术,以24m跨度先、后张梁为分析对象,使用SAP93静、动力通用分析软件建立8节点块体元力学模型,对先张混凝土箱梁进行应力、刚度、剪力滞后、畸变、翘曲、支座脱空效应、局部效应等力学性能分析,并重点与后张梁的力学性能进行对比。结果表明:先张梁与后张梁尽管施工工艺不同,只要预应力度基本相同,两者内力、变形特性基本相近。

Through the finite element technology, taking two 24 m-span pre-stressed concrete simply-supported box beams constructed by pre-tensioned system and post-tensioned system as the research object, the authors constructed a mechanics model of 8 node-block element with SAP93 static and dynamic general analysis software, analyzed the stiffness, the spear lag, the aberration, the warp, the un-equalized support and the local effect of the pre-tensioned pre-stressed concrete box beam. They compared these mechanics characters with those of the post-tensioned pre-stressed concrete box beam. The comparison concludes that the construction craftwork between pre-tensioned pre-stressed concrete box beam and the post-tensioned pre-stressed concrete box beam may be different, but if their pre-stressing level is the same, the internal force and distortion of the two are almost the same.