后张部分无黏结预应力梁锚固失效下受力性能试验研究  

Experimental study on performance of post-tensioned unbonded prestressed beams with anchorage failure

作　　者：周凌宇[1,2] 刘家豪 方蛟鹏 MAHUNON Akim Djibril Gildas 李亚民 黄巍 刘晓春[1,2] ZHOU Lingyu;LIU Jiahao;FANG Jiaopeng;MAHUNON Akim Djibril Gildas;LI Yamin;HUANG Wei;LIU Xiaochun(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China;Sinohydro Engineering Bureau 8 Co.Ltd.,Changsha 410004,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程实验室,湖南长沙410075 [3]中国水利水电第八工程局有限公司,湖南长沙410004

出　　处：《中南大学学报（自然科学版）》2023年第7期2768-2778,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51978662);中建五局科研项目(cscec5b-2021-05)。

摘　　要：为了研究部分无黏结及锚固系统失效对后张预应力梁受力性能的影响,以4根后张法施工预应力混凝土简支梁为试验对象,分析后张法预应力梁在相同无黏结率下,跨中、梁端部分无黏结以及锚固系统失效时的受力过程、破坏形态、荷载-位移曲线、延性等指标和抗弯性能的变化规律。基于部分无黏结预应力梁的试验结果,采用考虑锚固失效损失的截面应变协调黏结折减系数计算抗弯承载力。研究结果表明:部分无黏结与锚固失效均降低试验梁的抗裂性能;在锚具失效条件下,跨中纯弯段无黏结显著降低试验梁的刚度和承载力,而梁端无黏结对梁刚度影响较小,承载力略降低;在锚固失效下,跨中段无黏结和梁端无黏结的梁与正常状态下的梁相比,延性指标分别提高6.3%和21.1%;在加载过程中,跨中控制截面满足平截面假定;采用考虑锚固失效损失的截面应变协调黏结折减系数计算抗弯承载力与试验值较吻合。In order to study the influence of partial unbonded and anchorage system failure on the mechanical properties,four post-tensioned prestressed concrete simply supported beams were taken as test objects.The flexural behavior of post-tensioned prestressed beams such as loading process,the failure pattern,loaddisplacement curves and ductility were considered under the condition of partial unbonded with the same unbonded rate and anchorage system failure.Based on the experimental results of partially unbonded prestressed beams,the flexural capacity was calculated using the section strain-coordinated bond reduction coefficient considering anchorage failure loss.The results show that partial unbonded and anchorage system failures both reduce the crack resistance of the tested beam.Under the condition of anchorage system failure,the stiffness and bearing capacity of the beams are reduced significantly when debonding in the middle span region,while the beam with unbonded region at beam ends exhibits similar stiffness and slightly reduces bearing capacity.Compared with the beams under normal conditions,the ductility index of the beams without bond in the middle span and the beam without bond in the beam end with anchoring failure increase by 6.3%and 21.1%,respectively.The mid-span control section satisfies the plane section assumption during loading.The flexural capacity calculated using the section strain-coordinated bond reduction coefficient considering anchorage failure loss is in good agreement with the experimental results.

关 键 词：预应力梁 部分无黏结 锚固失效 抗弯承载力 黏结折减系数 

分 类 号：TU378.2[建筑科学—结构工程]