Seismic Resilience Assessment Of The Multi-story Frame Middle School Teaching Building Reinforced By Buckling Restrained Brace

With the proposal of the concept of resilient city,higher seismic requirements have been put forward for many single buildings of great value.The requirements for studying the earthquake recoverability of elementary and middle school teaching buildings and reducing the post-earthquake loss to restore normal function as soon as possible have also been widely proposed,but there are few studies on the assessment of seismic resilience.After the Wenchuan Earthquake,Chinese codes raised the primary and secondary school teaching buildings from standard fortification to key fortification.The original primary and secondary school buildings needed reinforcement design,and BRB buckling restraint support was commonly used as a reinforcement scheme in secondary school teaching buildings.This article takes the multi-layer frame primary and secondary school teaching buildings before and after BRB reinforcement as the research object.From the perspective of building seismic resilience evaluation,some discussions are made at the theoretical level.The paper work and main conclusions are as follows:1.The 8-degree fortified middle school teaching building was subjected to shock absorption and reinforcement design.The analysis model of the original structure and BRB reinforcement were established in ETABS.Incremental dynamic analysis and vulnerability analysis were used to obtain the structural vulnerability curve to evaluate the seismic performance of the original model and the reinforced model.The results show that,compared with the original structure,the use of BRB shock absorption and reinforcement can effectively reduce the maximum inter-story displacement angle of the structure,but it is not obvious for reducing the peak acceleration of the floor.2.Using the evaluation method of FEMA P-58,the performance model of the middle school teaching building was established to compare the repair cost,repair time and casualties under different earthquake intensities before and after reinforcement.The results show that the overall repair cost of the BRB model is much lower than that of the ordinary frame structure,which is mainly reflected in the repair of structural members,but for acceleration-sensitive components,the proportion of corresponding repair costs increases;the repair time is significantly reduced,the repair time of displacementsensitive components are greatly reduced,but the repair time of accelerationsensitive components are slightly increased.3.Combined with "Evaluation Standards for Building Seismic Toughness(Draft for Comment)",the rating indicators of structure were refined,and the seismic resilience of the two models was rated.The evaluation results show that the original model has too much repair cost and insufficient resilience.For the reinforced model,the repair cost and repair time index reflect better resilience,but it does not have the expected effect in terms of casualties.Improve the seismic resilience by reducing repair costs and shortening repair time.