预应力梁锚下有效预应力的快速检测方法研究  

Study of Rapid Inspection Method for Under-Anchorage Effective Prestress in Prestressed Beams

作　　者：艾辉林[1] 陈朝慰 戴文达 

机构地区：[1]上海应用技术学院城市建设与安全工程学院,上海201418 [2]福建省交通科学技术研究所,福建福州350004

出　　处：《世界桥梁》2015年第4期42-46,共5页World Bridges

基　　金：上海市自然科学基金(13ZR1441100)

摘　　要：针对反向张拉检测法不能通过整束预应力检测直接得到该束内单根预应力筋的张拉力,造成检测效率较低的问题,在现有反向张拉检测法的基础上进行预应力梁锚下有效预应力的快速检测方法研究。新方法将整束预应力反向张拉过程中其内单根预应力筋受力状态划分为夹紧和松动2种工作状态,单根的松动表现为整束预应力刚度的变化,利用整束预应力的张拉荷载∽位移曲线,直接推导该束内各单根预应力筋张拉力的关系式,据此计算锚下有效预应力。工程实例应用结果表明,该方法能够通过整束预应力检测直接得到该束内单根预应力筋的张拉力,在保持检测精度的前提下有效加快预应力筋检测效率。Given that the reverse tensioning inspection method is not possible to directly check the tensioning force of individual prestressing tendons by inspecting a whole prestressing bundle and the inspection efficiency is low,the study of a rapid inspection method for under-anchorage effective prestress of the prestressed beam is conducted based on the existing reverse tensioning inspection method.In the new method,the load bearing conditions of individual prestressing tendons during the reverse tensioning of the whole bundle of prestress were examined in the contexts of being tightened and loosened.If an individual prestressing tendon is loose,the rigidity of the whole bundle of prestress would change.Therefore,the tensioning load∽displacement curve of the whole bundle of prestress can be directly used to deduce the relatiional expression of the tensioning force of each prestressing tendon in a bundle,and based on which the under-anchorage effective prestress is calculated.Engineering practice proves that the method is able to directly test the tensioning force of individual prestressing tendons in a bundle by inspecting the prestress of the whole bundle and can effectively expedite the efficiency of prestressing tendon inspection on the premise that the inspection precision is guaranteed.

关 键 词：预应力钢筋混凝土桥 梁式桥 有效预应力 快速检测 反向张拉 整束预应力 单根预应力筋 

分 类 号：U446[建筑科学—桥梁与隧道工程]