钢支撑加固既有丙类框架结构抗地震倒塌能力

Seismic collapse resistance of original Class-C frame structure after steel support reinforcement

针对某既有混凝土框架结构使用功能改变,设防类别由丙类提高为乙类导致结构抗震性能不足的问题.在不提高框架抗震等级的前提下,采用钢支撑进行加固,研究了支撑数量、布置方式对结构抗震性能的影响并得到最佳加固方案.借助软件EPDA对加固后结构进行了动力弹塑性时程分析,采用IDA方法研究了加固前后结构的抗倒塌能力.研究结果表明:采用部分柱包钢、钢支撑复合加固后结构抗倒塌能力满足乙类结构设防要求,可以不考虑设防类别提高造成的抗震构造上的不足,加固工作量大大降低.

Aiming at the existing problems that the fortification class of the original concrete frame structure rises from Class-C to Class-B resulting in deficient anti-seismic capacity of the structure, and on the premise of not increasing the frame anti-seismic class, the reinforcement is conducted by steel support, the influences of steel support number and layout on the anti-seismic performance of a structure are studied, and the optimal reinforcement scheme is obtained. Then, the dynamic elastic-plastic time history analysis of the reinforced structure is carried out with the help of the software EPDA, and the IDA method is used to study the collapse-resistance capacity of the structure before and after the reinforcement. The study shows that the collapse-resistance capacity of the structure reinforced with partly steel-coated columns and steel support can satisfy the Class-B seismic fortification requirements, the structural flaws of the reinforced structure can be ignored, and the amount of reinforcement work is significantly reduced.