单箱八室波纹钢腹板PC箱梁桥预应力施加效率研究

Study of Prestress Introduction Efficiency of PC Eight-Cell Single Box Beam Bridge with Corrugated Steel Webs

为研究单箱多室波纹钢腹板PC箱梁桥施工过程中预应力施加情况,以郑州市某市政高架桥(38m+56m+38m)为背景,实测了体内、体外预应力钢束张拉阶段箱梁底板应力,并与有限元计算结果进行了对比,验证了实测结果的有效性,根据实测结果对预应力的施加效率进行了计算分析。研究结果表明:对比同一截面两阶段底板正应力值,体内预应力钢束张拉阶段均比体外预应力钢束张拉阶段高;相对于普通混凝土箱梁或组合箱梁,波纹钢腹板组合梁桥的预应力施加效率有大幅提高。

To study the condition of prestress introduction during the construction process of the PC multi-cell single box beam bridge with corrugated steel webs,a municipal viaduct in Zhengzhou,with spans of 38,56 and 38 m,was taken as the study background.The stresses in the base slab of the box beam during the tensioning of external and internal prestressing tendons were measured,and the data were compared with data gained by finite element calculation.The significance of the measured data was checked,and the prestress introduction efficiency was calculated and analyzed in accordance with the measured data.The normal stress values in the same base slab section during the tensioning of internal prestressing tendons and external prestressing tendons were compared.The results show that the stresses during the tensioning of internal prestressing tendons are higher than those during the tensioning of external prestressing tendons.Compared with the conventional concrete box beam and the composite box beam,the prestress introduction efficiency of the composite beam bridge with corrugated steel webs got great improvement.