持续荷载作用下外贴FRP片材加固混凝土梁承载力影响因素分析  

PRELOADING EFFECT ON LOAD-CAPACITY OF RC BEAMS STRENGTHENED WITH FRP LAMINATE

作　　者：丁亚红[1] 王兴国[2] 曾宪桃[1] 成香莉[1] 

机构地区：[1]河南理工大学土木工程学院,河南焦作454000 [2]中南大学土木建筑学院,湖南长沙410075

出　　处：《工程力学》2007年第z1期154-158,共5页Engineering Mechanics

基　　金：河南省高校杰出人才创新工程项目(2007KYCX006);河南省教育厅自然科学研究计划项目(2006560003)

摘　　要：为探讨结构不卸载或部分卸载情况下外贴纤维片材加固时,结构初始状态对承载力设计计算的影响,根据极限状态和容许应力法分析了受弯构件加固后承载力计算公式,考查了初始弯矩对承载力的不同影响。在改变配筋率、截面尺寸、初始弯矩、加固量等参数情况下,讨论了不同初始弯矩对加固梁分别按容许应力法和按极限状态计算的承载力变化影响情况。分析显示,初始弯矩对承载力的影响均比较小;而对大尺寸的等效桥梁模型试验结果表明,初始弯矩大小对承载力计算影响最大为6.2%,为保证安全和简化计算,加固设计时可在未考虑初始弯矩情况下承载力设计值基础上考虑一定的折减系数(0.9)进行设计,且偏于安全。Based on the calculation formulae for load bearing capacity of concrete members strengthened with FRP (Fiber Reinforced Polymer) laminate,the effect of initial moment on strengthened beams is discussed under two different states-ultimate limit state (ULS) and limited stress state for concrete and steel reinforcement. Various factors for calculating load-capacity of strengthened beams are analyzed,respectively,such as concrete strength,reinforcement ratio,cross-section size,and FRP area ratio,in order to discuss the effect of various initial moments on the flexural capacity. The analyzed results indicate that the effect of initial moment on the load-capacity is less than 2 per cent,and the experimental results of large-scale concrete beams at different levels of sustained load shows that the effect of initial moment on the load-capacity is no more than 6.2 per cent. To ensure the safety of strengthening design,the designing formula under sustained load may consider a reduction coefficient (0.9) on the design moment of strengthened member without initial moment.

关 键 词：混凝土梁 加固 FRP片材 初始弯矩 承载力 

分 类 号：TU311.2[建筑科学—结构工程]