后张有粘结预应力钢束断裂试验与数值研究  

Experimental and Numerical Study on Fracture of Bonded Tendons in Post-tensioned Members

作　　者：蓝天云 肖丹 颜希涵 熊猛 董占发 Lan Tianyun;Xiao Dan;Yan Xihan;Xiong Meng;Dong Zhanfa(China General Nuclear Power Design Co.Ltd.(Shenzhen),518031,China;Southeast University,Nanjing 211102,China)

机构地区：[1]深圳中广核工程设计有限公司,518031 [2]东南大学,南京211102

出　　处：《特种结构》2022年第5期17-24,共8页Special Structures

摘　　要：针对后张有粘结预应力混凝土结构中预应力钢束断裂检测的难题,本文提出通过监测构件表面应变的改变来监测预应力构件中钢束发生的断裂。首先,对预应力钢绞线数量和长度不同的2个直线型试件和2个弧线型试件分别开展预应力钢束断裂的试验研究。试验中,通过电阻应变片测量钢束断裂前后构件表面应变的变化,并反映断裂钢束在灌浆料中是否获得重新锚固。然后,对试验构件建立有限元模型,以模拟预应力张拉、预应力孔道灌浆、预应力钢束断裂、断裂钢束在灌浆料中粘结滑移及重新锚固。通过有限元模拟结果和试验观测的对比,说明结合构件表面应变测量和有限元模拟的方法来监测预应力钢束断裂具有可行性。最后,初步建议了监测布置方案和预警阈值。To identify the fracture of bonded tendons in post-tensioned concrete(PC) structural members,this paper presents a new approach,by monitoring the strain change on the member surface due to the fracture of tendons inside.First,two straight PC members and two arc-shaped PC members,with different length and different number of strands,were tested to investigate the impact of tendon fracture on the surface strain field,which was measured with strain gauges.The change in the strain field can also reflects whether the broken tendon is re-anchored in the grout.Next,finite element models of the tested members are used to simulate the post-tensioning,the grout filling,the tendon fracture,the bond-slip,and re-anchoring of the broken tendon in the grout.By the comparison of the experimental results with the simulation results,the approach shows the feasibility to detect the tendon fracture by combining surface strain measurement and finite element method.At last,a preliminary monitoring scheme with alarm threshold is proposed for detecting tendon fracture.

关 键 词：后张 有粘结预应力钢束 钢束断裂 粘结滑移 重新锚固 

分 类 号：TU378[建筑科学—结构工程]