折线先张预应力混凝土箱梁钢绞线锚固区应力研究  

Study on Local Stress of Strand Anchorage Zone for Prestressed Concrete Box Beams with Pre-tensioned Bent-up Tendons

作　　者：刘立新[1] 王新宇[1] 

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《郑州大学学报（工学版）》2010年第5期74-77,共4页Journal of Zhengzhou University（Engineering Science）

基　　金：河南省交通科研项目(2007P338)

摘　　要：针对某高速公路淮河桥35 m跨度折线先张预应力混凝土箱梁端部锚固区开裂的问题,根据梁端腹板厚度的变化、钢绞线锚固失效段的设置分4种工况对锚固区的局部应力进行了分析.结果表明:采用工况4的方案可有效减小梁端混凝土的局部应力防止开裂,即将梁端部的腹板厚度由原设计300mm增大为400 mm,同时部分钢绞线设置端部锚固失效段;提出了适当增加梁端腹板厚度、合理设置钢绞线锚固失效段等防止梁端混凝土开裂的措施,并通过实际工程梁端混凝土局部应力的量测进行了验证.In order to prevent concrete cracking at strands anchorage zone of prestressed concrete box beams of 35 m span with bent-up tendons in the bridge across Huaihe River,the analysis results on local stress at strand anchorage zone for 4 working states with different web thickness and different strand anchorage loss length for the box beams are given.The results show that local stress of concrete at strand anchorage zone may decrease obviously applying the measures of working state 4 that the thickness of web at the end is increased from 300 mm to 400 mm and the anchorage loss length of partial stands should be set.The measures increasing the web thickness and setting the anchorage loss length of strands at the end of beam to prevent concrete cracking are suggested and verified by the measurement results in practical engineering.

关 键 词：预应力混凝土 先张法 折线形预应力筋 锚固区 局部应力 

分 类 号：TU378.8[建筑科学—结构工程]