摘要
近年来,越来越多的T梁因预应力损失,导致梁体腹板出现裂缝,相较于其他加固方法,体外预应力加固能够产生较好的效果,为了保证加固效果,在整个施工过程中,对梁体锚下有效预应力的控制显得尤为重要。在桥梁施工过程中,在刚开始进行钢绞线的张拉阶段,利用反张法设备,选取一定数量的钢束进行检测,根据检测数据来判断张拉的情况是否符合设计要求,对不符合设计要求的T梁进行处理并总结经验,避免再次出现同样的问题。经实际检测表明:限位板的槽口深度、张拉设备、锚垫板处包裹的混凝土和PE管内的油脂对锚下有效预应力产生明显影响;采用反张法进行检验可有效避免预应力超欠张的情况,保证了加固桥梁的施工质量,同时也为T梁体外预应力加固的有效预应力测试提供了新的测试方法和经验。
In recent years,more and more T-beams have cracks in the beam web due to the loss of prestress.Compared with other reinforcement methods,external prestress reinforcement can produce better results.In order to ensure the reinforcement effect,the entire construction process among them,it is particularly important to control the effective prestress under the beam anchor.In the bridge construction process,especially at the beginning of the tensioning stage of the steel strands,a certain number of steel beams are selected for testing using the instrument of the reverse tension method,and then based on the testing data to determine whether the tensioning situation meets the design requirements.Deal with T-beams that do not meet actual requirements and summarize experience to avoid the same problem next time.The actual inspection found that the depth of the notch of the limit plate,the tensioning equipment,the concrete wrapped at the anchor pad and the grease in the PE pipe can have a significant impact on the effective prestress under the anchor.The use of the back tension method for inspection can be effective It avoids over-under-tension of pre-stress,guarantees the construction quality of the reinforced bridge,and at the same time provides new test methods and experience for the effective pre-stress test of external pre-stress reinforcement of T-beams.
作者
史振伟
张春雨
袁博
杨邓怜
SHI Zhen-wei;ZHANG Chun-yu;YUAN Bo;YANG Deng-lian(Yunnan Science&Technology Research Institute of Highway,Kunming 650051,China)
出处
《河南城建学院学报》
2022年第3期34-38,44,共6页
Journal of Henan University of Urban Construction
基金
云南省交通运输厅科技项目(云交科教[2018]13号)
云南省交通运输万科技创新及示范项目(云交科教便[2021]86号一(二))。
关键词
T梁
体外预应力加固
有效预应力
T-beam
external prestress reinforcement
effective prestress
