施工误差影响下的超长空间预应力束摩阻系数识别研究

预应力构件中的超长空间曲线束其预应力损失通常较大,而施工误差的存在又会增加预应力损失而降低有效预应力,对结构通常会带来不利影响。因此,在预应力结构分析中,有必要考虑施工误差的影响,对超长空间曲线束的预应力损失进行实测并对计算预应力损失的相关系数进行修正,以此考察实际预应力损失对成桥结构的影响。本文则以某连续梁桥的底板通长束为例,通过现场实测钢绞线应力以及理论分析来确定对预应力损失影响最大的摩阻系数值,再依此进行结构有限元模型修正,研究由施工误差导致的预应力损失对成桥结构的影响。

Study on the identification of the friction coefficient of ultra-long space prestressed beams under the influence of construction errors

In prestressed components, the prestress loss of ultra-long spatial curved beams is usually large, and the existence of construction errors will increase the prestress loss and reduce the effective prestress, which usually has an adverse effect on the structure. Therefore, in the analysis of prestressed structures, it is necessary to consider the influence of construction errors, measure the prestress loss of ultra-long spatial curved beams, and revise the relevant coefficients for calculating prestress loss to examine the impact of actual prestress loss on the bridge structure. This paper takes the bottom plate through-length beam of a continuous beam bridge as an example, determines the value of the friction coefficient that has the greatest impact on prestress loss through field measurement of steel strand stress and theoretical analysis, and then revises the structural finite element model based on this to study the impact of prestress loss caused by construction errors on the bridge structure.