混凝土索塔锚固区环向预应力布设位置优化  

Optimization of Circumferential Prestress Layout in Anchorage Zone of Concrete Cable Tower

作　　者：张亚军 ZHANG Ya-jun(Shanxi Road&Bridge Construction Group Co.,Ltd.,Taiyuan,Shanxi 030006,China)

机构地区：[1]山西路桥建设集团有限公司,山西太原030006

出　　处：《山西交通科技》2021年第6期69-73,共5页Shanxi Science & Technology of Transportation

摘　　要：针对混凝土索塔锚固区环向预应力的布设方式和位置问题,以某高速公路跨江大桥为背景,采用ABAQUS实体节段模型进行分析计算,比较3种双层预应力配束方案,并对钢束在布设位置进行对比和优化。结果表明:井字形配束环向力效率偏低;横桥向开口U形配束受力优于纵桥向开口U形配束;横桥向预应力束向齿块方向偏移可大幅提高锚固齿块的抗裂能力。沿桥塔水平方向,桥塔节段可近似为矩形框架受力,合理配置的环向预应力可抵消索力作用效应。沿桥塔高度方向,在靠近塔顶位置应增加竖向抗裂钢筋的配置,预应力配束向下可逐步减少。最终施工方案中采用横桥向开口双层应力束,受力良好,可为同类桥梁的设计提供借鉴。Focusing on problems of the layout and position of the circumferential prestress in the anchorage zone of the concrete cable tower,taking a expressway bridge across the river as the example,using ABAQUS solid segment model to analyze,calculate and compare three kinds of double-layer prestressing tendons,and the layout of the steel tendon is compared and optimized.The results show that,the circumferential stress efficiency of gridshaped tendon is low,and the stress of U tendon with transverse opening is better than that of U tendon with longitudinal opening.When the transverse prestressing tendon shifts toward the gear block,the crack resistance of the anchorage gear block can be greatly improved.Along the horizontal direction of the bridge tower,the tower segments can be approximately regarded as rectangular frame to bear the stress,and the properly arranged circumferential prestress can counteract the cable forces.Along the vertical direction of the bridge tower,the configuration of vertical anti-crack reinforcement should be increased near the top of the tower,and the prestressing tendons can be gradually reduced downward.The final construction scheme adopts double-layer stress tendon with transverse opening,which has good stress,and it can provide reference for similar bridge design.

关 键 词：斜拉桥 索塔锚固区 环向受力模型 预应力配束 有限元 应力分布 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]