斜拉桥施工监控中混凝土应力换算方法

A Method About Concrete Stress Conversion in Construction Monitoring of Prestressed Concrete Cable Stayed Bridge

通过对预应力混凝土斜拉桥的应力监测结果分析 ,发现混凝土在加载龄期较早时的收缩徐变较大 ,直接用所测得的钢筋应力通过弹模比法换算求得的混凝土应力值与理论值相差较大 .针对在加载龄期较早情况下 ,考虑混凝土的收缩徐变引起的钢筋和混凝土之间的应力重分布 ,通过静力平衡和变形协调条件 ,由实测钢筋应力算出的混凝土应力与理论计算值吻合较好 ,相应的收缩徐变总量与规范值较接近 .本文方法在某独塔预应力混凝土斜拉桥监控中取得了比较满意的结果 .

This paper presents a method of calculating concrete stress for the monitoring of prestressed concrete cable stayed bridge. In the concrete loaded early circumstances, shrinkage and creep of concrete is serious. Stress redistribution should be considered. Here, by solving the balancing equation and condition of deforming compatibility, concrete stress is obtained and identical to the theory and total of shrinkage and creep are close to the answer. The method has been applied in a single-tower prestressed concrete cable stayed bridge.