基于损伤指数的钢筋混凝土框架结构震后安全性鉴定新方法——试验研究

A new method for safety assessment of reinforced concrete frame structures after earthquakes by using damage index: experimental research

地震后迅速对震区的建筑结构进行准确的安全性鉴定至关重要。目前,我国地震现场建筑物损伤鉴定仍主要由专家依据经验给出判定结果。这样的方法难以避免由于鉴定者对结构震害现象的主观理解不同而导致的鉴定结果的差异,鉴定结论客观性不足。为解决这一问题,本文以钢筋混凝土框架结构为研究对象,提出一套基于损伤指数的结构震后安全性鉴定新方法。文中首先进行了一系列典型钢筋混凝土构件(8根柱试件、4根梁试件)的低周反复加载试验,记录下构件在每级控制位移下的损伤照片,并计算出相应的损伤指数,建立典型构件损伤指数和宏观损伤现象的对应关系,给出图例集;随后研究并筛选出合理的依据构件损伤指数计算整体结构损伤指数的方法;进而依据结构损伤指数给出损伤水平鉴定结果。最后,以一幢鲁甸地震中发生严重损伤的钢筋混凝土框架结构为例,采用本方法进行损伤鉴定,并与地震现场专家给出的鉴定结果相比较,验证了本方法的可行性。

It is really important to give an accurate safety assessment result for damaged buildings quickly after an earthquake. At present, the safety assessment of buildings after earthquakes mainly depends on experience and visual judgment of the experts. Such an approach is difficult to avoid the deviation of the assessment results due to the different understandings from various experts. In order to solve this problem, this study developed a new method for earthquake safety assessment of buildings, which has more objective index. First, pseudo-static tests were carried out for a series of typical reinforced concrete specimens （ eight columns and four beams）. Photos recording the damage phenomena of these specimens under each characteristic displacement level were taken during the tests. Also, tween damage damage indices of these specimens at these displacement levels were calculated. Then the correspondence bephenomenon and damage index of these typical RC components were established. After that, an appropriate method was addressed and chosen to calculate the damage index value of the damaged building according to the index value of each story RC frame structure （ damage component. Then the damage level of the building can be determined. Finally, a fourdamaged during the Ludian earthquake in 2014） was chosen as a studying case. The level of the structure was evaluated by using the method proposed in this study. The evaluating resuh of our method was compared with that given by the experts shortly after the earthquake. Then the feasibility of our method was verified.