摘要
混凝土的收缩徐变会引起混凝土连续梁桥不断上拱或下挠。当前国内在建高速铁路中许多混凝土连续梁桥将采用无碴轨道,其可调性很小,必须控制铺轨后的徐变变形(后期徐变变形)。对几种常用规范的混凝土徐变系数影响因素、计算公式进行了对比研究,并以武广客运专线上一座(70+125+70)m混凝土连续梁桥为例,模拟整个施工过程按几个常用规范对该桥进行对比分析计算,研究了混凝土的收缩徐变对桥梁变形和截面应力的影响。计算结果显示,混凝土的收缩徐变引起的桥梁后期徐变变形不可忽视;根据不同规范计算得出的桥梁后期徐变变形差别较大。
The shrinkage and creep of concrete will make concrete continuous beam bridges hogging or deflecting continuously. Currently, ballastless track is applied in many concrete continuous beam bridges in the construction of China＇s high-speed railway. However, ballastless track can be little adjusted. Consequently, creep deformation of concrete after laying track （post creep） must be controlled. Comparative study is made of the influencing factors and calculating formulae of creep coefficients of several common codes. Then a （70 ＋ 125 ＋ 70）m concrete continuous beam bridge is taken as an example. The whole construction procedure is simulated and the deformations are calculated according to the several common codes and the results are compared. The influence of the shrinkage and creep of concrete on bridge deformation and section stress is studied. The resuits reveal that the bridge post creep deformation caused by the shrinkage and creep of concrete must not be ignored and the differences between the results of different codes are notable.
出处
《石家庄铁道学院学报》
2008年第3期62-65,共4页
Journal of Shijiazhuang Railway Institute
关键词
混凝土连续梁桥
无碴轨道
徐变系数
后期徐变
concrete continuous beam bridge
ballastless track
creep coefficient
post creep deformation
