高性能粉煤灰混凝土桥梁徐变变形控制研究

Research on Creep Deformation Control of High Performance Fly Ash Concrete Bridge

为了降低徐变变形对桥梁结构性能、使用寿命及安全性的不利影响,提出一种高性能粉煤灰混凝土桥梁徐变变形控制方法。以高性能粉煤灰混凝土为例,构建有限元模型,获取桥梁的徐变参数,并提出延长铺轨时间、设计铺设恒载的顺序、策划体内和体外预应力束徐变变形控制方法。结果表明:使用4种控制方法后有效降低了徐变变形引起的桥梁下挠值与桥梁上拱值,有效控制了混凝土桥梁的后期变形,说明所提方法是合理可行的,可为今后工程设计提供一定的理论依据。

In order to reduce the adverse effects of creep deformation on the performance,service life,and safety of bridge structures,a high-performance fly ash concrete bridge creep deformation control method is proposed.Taking high-performance fly ash concrete as an example,a finite element model is constructed to obtain the creep parameters of the bridge,and to propose methods for extending the track laying time,designing the sequence of laying dead loads,and planning the creep deformation control of internal and external prestressed tendons.The results showed that the use of four control methods effectively reduced the deflection and arch values of the bridge caused by creep deformation,and effectively controlled the later deformation of the concrete bridge.This indicates that the proposed methods are reasonable and feasible,and can provide a certain theoretical basis for future engineering design.