锈蚀RC框架结构连续倒塌抗力机制研究  

Study on load resisting mechanism of corroded RC frame structures against progressive collapse

作　　者：钱凯[1,2] 黄志强 翁运昊 于晓辉 QIAN Kai;HUANG Zhiqiang;WENG Yunhao;YU Xiaohui(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Building New Energy and Energy Conservation,Guilin University of Technology,Guilin 541004,China;School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]桂林理工大学广西建筑新能源与节能重点实验室,广西桂林541004 [3]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2022年第9期181-190,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51778198);广西科技基地和人才专项(2021AC19076)。

摘　　要：为研究钢筋锈蚀对钢筋混凝土(RC)框架结构连续倒塌抗力机制的影响,对3个1/2缩尺RC梁-柱子结构开展了拟静力Pushdown试验,其中1个未锈蚀RC梁-柱子结构作为对照,另2个RC梁-柱子结构在节点区采用电化学加速锈蚀方法模拟钢筋锈蚀。试验结果表明:钢筋锈蚀会影响RC梁-柱子结构的裂缝开展顺序及钢筋断裂位置,同时钢筋锈蚀会削弱压拱机制及悬链线机制对RC结构抗连续倒塌能力的提升作用。在边节点锈蚀率为28.6%和中节点锈蚀率为5.2%的情况下,RC梁-柱子结构的第一峰值荷载和极限荷载分别降低了31.2%和57.4%。基于试验结果,通过对比分析验证不同压拱机制理论计算模型及悬链线机制理论计算模型评估锈蚀RC梁-柱子结构连续倒塌抗力机制的有效性。通过对比分析发现:Lu等提出的模型用于评估锈蚀RC梁-柱子结构压拱机制下的第一峰值荷载的准确性高且离散性低;Yu等所提模型对锈蚀RC梁-柱子结构悬链线机制下极限荷载的评估结果较为准确,但偏于保守。Three 1/2 scaled reinforced concrete(RC) beam-column substructures were tested under quasi-static pushdown loading regime to study the effects of reinforcement corrosion on the progressive collapse resistance mechanism of reinforced concrete(RC) frames. Among them, one specimen was designed without considering corrosion for comparison, and the other two specimens were corroded at the joint zones by the electrochemical acceleration method. The test results indicate that reinforcement corrosion may change the sequence of crack development and the location of rebar fracture. In addition, reinforcement corrosion may degrade the efficiency of compressive arch action and catenary action for enhancement of the collapse resistance. Under the corrosion degrees of 28.6% at side connections and 5.2% at middle connection, the first peak load and ultimate capacity of the RC beam-column substructure are reduced by 31.2% and 57.4%, respectively. Based on experimental results, comparative analysis was carried out to evaluate the reliability of existing analytical models for compressive arch action and catenary action when reinforcement corrosion was considered. It is found that the model proposed by Lu et al. can predict the first peak load under the compressive arch action of corroded RC frames with high accuracy and low discreteness. Regarding the ultimate capacity under catenary action, the model proposed by Yu et al. provides acceptable accuracy with slight conservation.

关 键 词：RC框架 钢筋锈蚀 连续倒塌 拟静力试验 抗力机制 

分 类 号：TU375.4[建筑科学—结构工程] TU317.1