非均匀预应力筋束非线性松弛损失研究

Non-linear Relaxation Loss of Non-uniform Prestressing Steel Bundles

基于施工现场预应力筋束张拉锚固时锚下有效预应力实测数据,采用随机数生成方法模拟预应力筋束锚固初应力的非均匀分布特性,利用单根预应力筋松弛损失规律对非均匀预应力筋束的松弛损失进行了研究。结果表明:考虑筋束内初应力非均匀性的筋束平均松弛损失与初应力分布离散系数之间存在明显的非线性关系,可采用多项式予以拟合。结论可用于修正实际工程中预应力筋束松弛损失计算误差,并对预应力施工质量控制提供指标参考。

The field-tested non-uniform distribution characteristics of initial anchoring stresses in prestressing steel bundles were simulated with the random number production method,and the relaxation losses of bundles were studied based on the existing relaxation rule of the single prestressing strand. The results show that,if the unevenness of initial anchoring stresses in a prestressing steel bundle is considered,the average relaxation loss of the bundle is affected by the dispersion coefficient of the bundle＇s initial stress distribution in a distinct non-linear way,which is well fitted with polynomials. The work provides reference for the evaluation of prestressing steel bundles＇ relaxation losses and criteria for quality control in pre-stressed engineering construction.