中文摘要：

为确定塔墩梁固结体系矮塔斜拉桥在中跨合龙时所施加的纵向水平顶推力的合理取值范围,从控制桥墩裂缝宽度的角度出发推导其简化计算方法。基于《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTG D62-2004）中的裂缝宽度公式,推导双肢薄壁墩塔墩梁固结矮塔斜拉桥在顶推阶段和正常使用阶段的桥墩裂缝宽度与顶推力的关系式,由此确定合龙顶推力的取值范围,在此基础上考虑合龙温差对顶推力进行修正。以104国道上某三塔矮塔斜拉桥为例,计算该桥在中跨合龙时的顶推力,并与有限元计算结果进行对比,验证了该简化计算方法的有效性,且该方法具有较高的精度和计算效率。

英文摘要：

To determine the reasonable value ranges of the longitudinal horizontal jacking forces to be applied to the extradosed bridge with rigid fixity of the pylons, piers and main girder at the time the central span of the bridge was being closed, a simplified calculation method of the jacking forces was deduced from the point of control of the crack width in the piers. Based on the crack width formula as provided in the Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts （JTG D62-2004） , the relationships between the crack width in the piers and the jacking forces of the bridge with the double-leg thin-walled piers at the jacking stage and normal service stage were also deduced. In accordance with the relationships, the reasonable value ranges of the jacking forces were determined and the jack forces were then modi-fied wherever necessary through taking account of the temperature differences of the closure. By way of example of a three-pylon extradosed bridge on the National Route 104, the jacking forces for the closure of the central span of the bridge were calculated, the calculated jacking forces were compared to the finite element calculations and the method was thus verified to be effective and have high accuracy and high calculation efficiency.