连钢箍接头服役混凝土电杆的性能评估及加固研究  

Performance evaluation and strengthening analysis on serving reinforced concrete poles with steel ring joint

作　　者：徐金俊[1] 陈宗平[1,2] 夏开全[3] 李伊[1] 

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,南宁530004 [3]中国电力科学研究院,北京100055

出　　处：《应用力学学报》2014年第2期288-293,317,共6页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(50908057);广西防灾减灾与工程安全重点实验室系统性研究项目(2012ZDX03)

摘　　要：为了揭示带钢箍接头服役混凝土电杆的破坏机理和承载性能,对3根长4.2m、3根长3.5m的带有钢箍接头的混凝土电杆以及3根长4.2m采用碳纤维布(CFRP)加固的钢箍接头电杆进行了抗弯承载力试验。通过试验观察了各试件的受力全过程和破坏形态,并获取了荷载-挠度曲线、刚度退化规律曲线、极限承载力等重要指标。研究结果表明:未加固试件的破坏形态大多为混凝土拉裂、接头钢箍不屈服,具有明显的脆性;加固接头试件的破坏过程迅速,主要表现为混凝土与CFRP的表面粘脱失效而破坏,过程迅速,具有脆性破坏特点,黏贴双层碳纤维布试件比采用单层碳纤维布试件的承载力提高了32.8%;对比加固和未加固接头的试件,经单层加固后电杆的承载力提高58.8%、初始弹性刚度提高达3倍,且延性性质也有所改善;但加固与未加固试件的耗能能力大致相当,其截面应变均符合平截面假定。In order to reveal the failure mechanism and load bearing capacity properties of serving Reinforced Concrete Poles(RCP), three poles with 4.2m length, three poles with 3.5m length and three RCP with steel ring joint strengthened CFRP(Carbon Fiber Reinforced Plastic) are conduct experiments of flexural capacities. According to the test, the whole process of forcing and failure mode is observed, and important indicators of load-deflection curves, stiffness degradation rule curves and ultimate bearing capacity are obtained. Results show that the failure models of majority of nonreinforced specimens are concrete creaking and not yield steel ring joint, and their failures are obviously brittle. The mean strains of specimen cross-sections meet the assumption of plane-section. The damage of reinforced specimens are mainly bonding failure between the interface of concrete and CFRP, and the damage process is very rapid. The characteristic of damage is brittleness. The bearing capacity of specimens with double layers is 32.8% higher than that of single layer. The mean strains of strengthened specimen cross-sections also meet the assumption of plane-section. Comparison of different specimens, the bearing capacity and initial elastic stiffness of the late stage of poles reinforced are improved 58.8% and three times, respectively, and their ductility properties are also improved. The energy dissipation abilities of strengthen poles and non-strengthen poles are almost the same.

关 键 词：“服役”混凝土电杆 钢箍接头 碳纤维布 承载能力 刚度退化 

分 类 号：TU528[建筑科学—建筑技术科学]