桥梁中预应力混凝土T形梁预制阶段的力学分析

Mechanical Analysis at Stage of Pre-stressed Concrete of Prefabrication in Bridge

预制预应力混凝土T形梁的过程中,尤其是施加预应力后,梁体会产生向上反向挠度(即反拱度),某些情况下在梁体上缘还会出现纵向裂缝,这些问题在施工过程中往往难以定量地准确控制。本文以交通部标准图中标准跨径为30m的预应力混凝土T形梁为例,基于有限元理论,采用ABAQUS软件中的Drucker-Prager creep模型,模拟计算了预应力混凝土T形梁在钢筋预应力、温度梯度和混凝土徐变作用下的反拱度和纵向应力变化规律。

In the prefabricated stage of prestressed concrete T-beam, particularly after the imposition of prestressing, a reverse upward deflection （that is inverted camber） will appear; undercertain circumstances longitudinal cracks will appear on the edge of the beam. All these problems in the construction process are often difficult to accurately control quantificationally.Taking the 30 metres long-span of prestressed concrete T-beam of the standard plans in the Ministry of Communications for instance, based on finite element theory, adopting the Drucker-Prager creep model in Abaqus, Simula- tion calculation of prestressed concrete beams reinforced t-shaped in prestressed, temperature gradient and creep of concrete under the action of the inverted camber and longitudinal stress variation.