火灾后混凝土连续板剩余承载力试验研究及理论分析  

EXPERIMENTAL STUDY AND THEORETICAL ANALYSIS ON THE RESIDUAL CAPACITIES OF FIRE-DAMAGED CONCRETE CONTINUOUS SLABS

作　　者：王勇[1,2] 王功臣[1] 王本淼 钟波 部翼翔 任兆卿 WANG Yong;WANG Gong-chen;WANG Ben-miao;ZHONG Bo;BU Yi-xiang;REN Zhao-qing(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221008,China;Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221008,China;Hu'nan BDF Energy Saving Technology Co.,Ltd.,Hu’nan 415699,China;Sichuan Fire Research Institute of Emergency Management Department,Sichuan,Chengdu 610000,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点试验室,江苏徐州221008 [2]中国矿业大学江苏省土木工程环境灾变与结构可靠性重点实验室,江苏徐州221008 [3]湖南标迪夫节能科技有限公司,湖南415699 [4]应急管理部四川消防研究所,四川成都610000

出　　处：《工程力学》2022年第2期96-109,共14页Engineering Mechanics

基　　金：国家青年自然科学基金项目(51408594,51808129);应急管理部消防救援局重点攻关项目(2020XFZD14);徐州市自然科学基金项目(KC19014)。

摘　　要：为了研究火灾蔓延作用对混凝土灾后连续板力学性能影响,对4块灾后连续板进行承载力试验,研究了火灾蔓延工况、配筋率和配筋方式等对灾后板变形、混凝土和钢筋应变和破坏模式等影响规律;此外,考虑竖向剪切力影响,提出混凝土双向板拉压薄膜效应区域计算方法,建立灾后板极限承载力计算方法;采用不同理论,对灾后连续板各跨承载力进行对比分析。试验表明:灾后连续板各跨出现跨中弯曲破坏、局部冲切破坏、内支座冲切破坏和内支座弯曲破坏等多种破坏模式。相比火灾蔓延工况,受火时长、灾后爆裂程度、配筋率和配筋方式对灾后板剩余承载力有更为重要影响。结合变形破坏准则,采用该文方法可确定灾后板极限剩余承载力上限。To investigate the effect of traveling fire on the residual capacity of fire-damaged slabs,residual capacity tests of four fire-damaged concrete continuous slabs were conducted.The effects of the parameters,including the traveling fire scenario,reinforcement ratios and reinforcement layout,on the deflection,concrete and steel strains and failure mode of the continuous slabs were studied.In addition,the vertical shear force was considered.The tensile and compressive membrane action regions were proposed to determine the residual capacity of the fire-damaged slabs.For the limit residual capacity of each span in the fire-damaged continuous slabs,a comparative analysis was conducted based on different theories.The results show that several kinds of failure modes often appeared in the fire-damaged slabs,including the mid-span flexural failure,local punching shear failure,punching shear failure near the internal supports and flexural failure near the internal supports.Compared to the traveling fire scenario,the heating time,spalling,reinforcement ratio and reinforcement layout have more important influence on the residual capacities of the fire-damaged slabs.According to the deflection failure criterion,the present method can be used to determine the upper limit loads of fire-damaged slabs.

关 键 词：混凝土连续板 火灾蔓延 破坏模式 承载力 薄膜效应区域 

分 类 号：TU375[建筑科学—结构工程]