混凝土梁桥钢筋工作应力释放法试验研究

Study on stress release method of reinforced for concrete girder bridge

为更高精度地获取混凝土梁式桥当前的弯曲应力实际状态,采用相对匀质的普通构造钢筋进行了应力释放法研究.综合一维杆与薄圆盘导热方程,得到圆柱杆有限点上热传导解析解的可视化模型,重点确定混凝土梁式桥常见的构造钢筋类型、应力释放位置及释放峰值温度等影响因素.开展切割释放钢筋样本的室内模型构件试验,基于考虑切割释放温度场环境下温度应力修正模型得到了与各因素的理论变化规律一致的结论,表明文中建立的普通钢筋释放法的基础标准及释放温度修正模型方法正确、可靠.文中方法可获得更为客观的截面应力基础状态,为大跨度混凝土桥梁的延续健康监测奠定了基础.

In order to get the actual bending stress of concrete girder bridge,experimental study of stress release on constructional reinforced bar with relatively homogeneous physical properties were conducted.By combining thermal conduction equation of one-dimensional bar with that of the thin plate,a visual model of thermal conduction solution for cylindrical reinforced bar was got.Factors such as reinforced type,stress release position and the peak releasing temperature etc.were emphasized.Basic standards and amendment on releasing temperature method were studied in detail through indoor test on a large number of releasing samples.It is concluded that the amendment on distribution of releasing temperature worked in accordance with the theoretical one.Thus,the variation principle was verified correctly.It has great significance for the acquisition of on sectional stress state in a more practical way.Furthermore,it laid a foundation for the continuous health monitoring of large-span concrete bridges.