关键词: 连续刚构桥, 竖向预应力筋, 预应力损失, 滞后张拉, 主拉应力, 措施, 建议

Abstract: Vertical prestressing bars play a great role in controlling the principal tensile stress of webs. According to existing norms, the ratio of the vertical prestress loss to different length of the vertical prestressing bars is analyzed. In view of the current design of the delay tensioning vertical prestressing bar, the impacts to the continuous rigid-framed bridge by each of the three different delay tensioning methods is analysed, and the reasonable prestressing time is given based on the analysis. The reasons for the webs in a single vertical prestressing bars under the stress distribution and on the edges of web tensile stress are analyzed in detail, by establishing the detailed FEM simulation model of webs, and then the advice how to avoid stress on the edge of tectonic is given.

Key words: continuous rigid-framed bridge, vertical prestressing bar, prestress losses, delay tensioning, principal tensile stress, measure, suggestion