火损后结构检测及评级的合理化分析与研究

Structure detection and rating after fire loss rationalization analysis and research

借助某厂房火灾工程实例,依据《火灾后工程结构鉴定标准》(T/CECS 252-2019)进行火灾后结构的初步鉴定和详细鉴定两阶段工作,特别在详细鉴定过程中严格按照标准要求对诸多材料折减系数进行了定量化地分析和选用;采用楼面堆载试验观察楼板实际承载能力和变形状况;结合《工业建筑可靠性鉴定标准》(GB50144-2019)对未受火灾影响的一层、轻度受火灾影响的二层和严重受火灾影响的三层统一厂房整体地进行安全性评级。结果表明,火损后构件混凝土抗压强度和弹性模量折减系数可采用加权系数平均法确定,其在构件截面上呈现梯度变化;由高温区出现的多道竖向裂缝在没有明显烧灼层情况下导致的构件承载力减弱应进行评估不可忽视;对于存在未受火灾影响区域和受到火灾影响区域的建筑,统一整体进行安全性鉴定时详细鉴定是必不可少的重要环节。可为类似火灾后工程结构处理提供参考。

With the help of an example of fire engineering occurring in an industrial plant,according to the new standard“Standard for appraisalof engineering structures after fire”(T/CECS252-2019),the preliminary identification of two stages of detection and identification,especially in the process of detailed identification in strict accordance with the requirements of the new standard provisions of many material reduction coefficient was a quantitative analysis and selection;Observe the actual bearing capacity and possible deformation status of the floor slab by using the pile-load test of the floor;Finally,according to the standard“Standard for appraisal of reliability of industrial buildings and structures”(GB50144-2019),the safety rating of the first floor,the second floor and the third floor seriously affected is fire.The results show that after fire loss,the compressive strength and elastic modulus reduction coefficient of the member concrete can be determined by the weighted coefficient average method,which presents gradient changes on the section of the member;the weakening of the component bearing capacity caused by the multiple vertical cracks in the high temperature area should be evaluated and can not be ignored;the detailed safety identification is an essential and important link for buildings with no fire affected areas and fire affected areas.This paper can provide reference for the treatment of similar fire.