火灾后钢管RPC柱近距离爆炸残余承载力研究  

EXPERIMENTAL STUDIES ON RESIDUAL CARRYING-CAPACITIES OF FIRE AND BLAST-DAMAGED RPC-FST COLUMNS

作　　者：邹慧辉 陈万祥 郭志昆 周子欣 ZOU Hui-hui;CHEN Wan-xiang;GUO Zhi-kun;ZHOU Zi-xin(State Key Laboratory of Disaster Prevention & Mitigation of Explosion &Impact,Army Engineering University of PLA,Nanjing 210007,China;School of Civil Engineering,Sun Yat-Sen University,Guangzhou 510275,China)

机构地区：[1]陆军工程大学爆炸冲击防灾减灾国家重点实验室,南京210007 [2]中山大学土木工程学院,广州510275

出　　处：《工程力学》2019年第7期184-196,共13页Engineering Mechanics

基　　金：国家自然科学基金项目(51378498,51578541);江苏省自然科学基金项目(BK20141066)

摘　　要：对梁-柱构件的轴向力和侧向爆炸荷载进行适当简化,提出了一种基于等效单自由度方法的近距离爆炸分析模型。首先对标准火灾和爆炸作用后的钢管活性粉末混凝土(Reactive Powder Concrete Filled Steel Tubular,简称钢管RPC)柱初始挠度进行估算,然后结合钢管混凝土统一理论给出残余承载力计算公式并对钢管RPC柱的爆炸损伤进行评估。通过大比例模型试验研究了标准火灾后钢管RPC柱的近距离爆炸残余承载力,分析受火时间和爆炸比例距离对残余承载力和破坏形态的影响。结果表明:理论计算结果与试验数据吻合较好,验证了该文计算模型的可靠性。钢管RPC柱的残余承载力损失范围为16%~67%,火灾和爆炸作用对钢管RPC柱承载力产生了不同程度的毁伤,且残余承载力对受火时间更为敏感。其中,仅受火105 min的钢管RPC柱承载力下降60%,而仅遭受爆炸作用的承载力下降16%;经历火灾作用再遭受爆炸荷载的钢管RPC柱承载力损失高达67%。对5根钢管RPC柱进行爆炸损伤评估:1根为轻度破坏,2根为中度破坏,2根为重度破坏,表明钢管RPC柱具有良好的抗火性能和抗爆性能。An equivalent Single-Degree-of-Freedom(SDOF)model is developed to predict the residual carrying-capacities of fire-damaged Reactive Powder Concrete-Filled Steel Tubular(RPC-FST)columns under axial lateral blast loadings.The initial deflections of fire and blast-damaged RPC-FST columns are derived by the proposed SDOF model,then the residual carrying-capacities and damage levels are further obtained based on the unified theory of Concrete-Filled Steel Tubular(CFST)members.The residual carrying-capacities of fire and blast-damaged RPC-FST columns are investigated by a series of large-scale blast-resistant tests,in which the influences of scale standoff distance and fire duration on residual carrying-capacities and failure modes are discussed.Experimental results show that the analytical results of residual load capacities and damage indexes are well validated by experimental data.The residual carrying-capacities of RPC-FST columns decreased by 16%― 67%,it means that the carrying-capacities would seriously degraded by fire and blast attacks,but it is more sensitive to fire duration than that to blast loading.It is indicated that the residual carrying-capacities of RPC-FST columns only experienced 105 min fire attack decrease by 60%,and only suffered blast loading decrease by 16%.However,the residual carrying-capacities of RPC-FST column suffered fire attack and following blast load would decrease by 67%.The damaged assessments of 5 RPC-FST columns indicate that one specimen is lightly damaged,two specimens are moderately damaged,and two specimens are severely damaged,respectively.The good performance for the fire-and blast-resistances of RPC-FST columns are experimentally verified.

关 键 词：标准火灾 爆炸荷载 钢管RPC柱 残余承载力 试验研究 

分 类 号：TU398.9[建筑科学—结构工程]