精细化模型在大悬臂预应力混凝土矮框架墩中的分析与应用  

Analysis&Application of Refined Models in Large Cantilever Prestressed Concrete Low-Frame Piers

作　　者：胡肖强 HU Xiao-qiang(Jiangsu Transportation Science&Technology Group Co.,Ltd.,Nanjing 210017,China)

机构地区：[1]苏交科集团股份有限公司,江苏南京210017

出　　处：《中国市政工程》2025年第1期119-121,125,150,151,共6页China Municipal Engineering

摘　　要：对大悬臂预应力混凝土矮框架墩而言,盖梁跨高比L/H较小,悬臂部分为比值小于5的深受弯构件,双柱间部分甚至为比值小于2的深梁构件,同时矮墩柱的高度和截面尺寸相差不大,剪跨比较小,此时的盖梁和墩柱空间效应均较明显。采用常规的杆系单元模型已经不能准确模拟结构的受力情况,其结果失真,与实际不相符合,会使得设计偏于保守或偏于不安全。文章采用精细化有限元模型FEA对大悬臂预应力混凝土矮框架墩建立2个实体空间模型,并与标准墩高的框架墩实体模型进行对比分析。结论如下:大悬臂预应力混凝土盖梁的应力分布不均匀,有明显的应力集中现象,截面应力应变不符合平截面假定;实体薄壁墩整体应力相对均匀,其竖向变形、上下缘应力和主拉应力等均小于双柱墩,墩柱受温度影响的内力也小于双柱墩。For large cantilever prestressed concrete low-rise frame piers,the girder span-to-height ratio(L/H)is small,with the cantilevered section being a deep flexural component(span-to-depth ratio<5)and the inter-column section even a deep beam(span-to-depth ratio<2).Additionally,the height and cross-sectional dimensions of the low piers are similar,resulting in a small shear span ratio and significant spatial effects in both the girder and piers.Conventional bar element models can no longer accurately simulate the structural behavior,leading to distorted results that may result in overly conservative or unsafe designs.This paper employs a refined finite element analysis(FEA)model to establish two solid spatial models of the large cantilever prestressed concrete low-rise frame piers and compares them with a standard-height frame pier model.The conclusions are as follows:the stress distribution of the prestressed concrete cantilever girder is uneven,with significant stress concentrations,and the sectional stress-strain relationship does not conform to the plane section assumption.The solid thin-walled pier exhibits relatively uniform overall stress,with smaller vertical deformations,edge stresses,and principal tensile stresses compared to the double-column pier,and the internal forces of the pier columns affected by temperature are also smaller.

关 键 词：精细化模型 大悬臂 矮框架墩 分析 

分 类 号：U442.54[建筑科学—桥梁与隧道工程]