大跨度预应力混凝土梁配筋与技术优化研究

Research on Reinforcement and Technical Optimization of Large-span Prestressed Concrete Beams

文中根据现有资料和规范对大跨度混凝土预应力梁进行了设计和计算,分析了预应力梁施工时对其他构件的影响。研究表明,大跨度预应力梁预应力筋总数初步估计为76根,采用平均压应力法计算得出的预应力筋数量最少,经济性较高;采用换算配筋率法计算出的预应力筋数量最多,结果偏保守。各截面预应力损失在17.6%~24.2%,预应力反拱值最大为14.84 mm,挠度最大为16.84 mm,支座和跨中截面均未出现裂缝,满足规范和设计要求。采取了主体整浇方案,该方案能够有效减小预应力构件引起的次内力,提高挡土墙的防水能力。

This paper designs and calculates the long-span prestressed concrete beam according to the existing data and code requirements,and analyzes the influence of the prestressed beam on other components during construction.The results show that the preliminary evaluation results show that the total number of prestressed tendons in long-span prestressed beams is about 76.The number of prestressed tendons calculated by the average compressive stress method is the least and the economy is high.The number of prestressed tendons calculated by the conversion reinforcement ratio method is the largest,and the result is conservative,which is suitable for conservative design decision.The prestress loss of each section is in the range of 17.6%~24.2%,the maximum prestress reverse arch value is 14.84 mm,and the maximum deflection is 16.84 mm.There is no crack in the bearing and mid-span section,which can meet the specification and design requirements.The main cast-in-place scheme is adopted,which can effectively reduce the secondary internal force caused by prestressed members and improve the waterproof function of the retaining wall.