水平底板索连续刚构桥运营阶段收缩徐变效应分析

Shrinkage and Creep Effect Analysis of a Continuous Rigid Frame Bridge with Horizontal Bottom Slab Cables during the Operation Stage

摘要: 为了研究混凝土收缩徐变效应对水平底板索连续刚构桥运营阶段力学性能的影响规律，本文以我国西南山区某水平底板索连续刚构桥为研究对象，采用Midas/Civil分析了成桥年限及徐变系数对桥梁挠度和顶底板应力的影响。研究表明，混凝土收缩徐变对水平底板索连续刚构桥顶底板应力的影响很小，但对桥梁下挠的影响较大。随着成桥年限的增大，桥梁下挠增大，且下挠受成桥年限的影响会逐渐减小；而随着徐变系数的增大，桥梁挠度几乎线性增长。此外，通过与曲线底板索连续刚构桥对比可知，水平底板索连续刚构桥的下挠受成桥年限及徐变系数变化的影响相对较小。

Abstract: In order to study the influence law of concrete shrinkage and creep effect on the mechanical properties of the continuous rigid frame bridge with horizontal bottom slab cables during the operation stage, this paper takes a continuous rigid frame bridge with horizontal bottom slab cables in the mountainous area of southwest China as the research object, and analyzes the influence of bridge formation age and creep coefficient on the deflection and the top and bottom slabs’ stresses of the bridge by using Midas/Civil. The study shows that the effect of concrete shrinkage and creep on the top and bottom slabs’ stresses of the continuous rigid frame bridge with horizontal bottom slab cables is small, but the effect on the bridge deflection is large. With the increase of the bridge formation age, the bridge deflection increases, and the deflection affected by the bridge formation age is gradually reduced; while with the increase of the creep coefficient, the bridge deflection increases almost linearly. In addition, by comparing with the continuous rigid frame bridge with curved bottom slab cables, it can be found that the deflection of the continuous rigid frame bridge with horizontal bottom slab cables is relatively less affected by the bridge formation age and the change of creep coefficient.