Study On Collapse Resistance Of RC Frame Structures Under Strong Ground Motions

Complexity occurs beyond the region fortification intensity earthquake earthquakeearthquake mechanism remains a possibility, concrete frame structure designed inaccordance with the norms in the repeated earthquake damage to a large number of theoverall collapse phenomenon, can not be achieved with the specification requirements“No damage in minor earthquake, repairable under moderate earthquake, no collapseunder mega earthquake” fortification objects. In recent years the U.S. ATC Committeeproposed structure earthquake resistance collapsed reserve coefficient method to assessthe seismic performance. In this paper,use this method to evaluat RC frame structuresdesigned in accordance with our specifications, analyze the factors that affect thestructural collapse resistance, and the proposed design method and reinforcementmeasures to improve the performance of structural collapse resistance. The mainresearch work and achievements are as follows:(1) Research on different fortification intensity concrete frame structure Seismiccollapse resistance. Incremental dynamic analysis method collapse resistance reservecoefficient method in accordance with the ATC-63report recommended the collapse ofprobability calculation, The analysis showed that7degrees fortified area Seismiccollapse resistance of RC frame structure is weak, anti earthquake collapsed reservescoefficient lower.(2) The study on impact of RC frame structures collapse resistance factors.Analysis of axial compression ratio, end-column moment amplification factor, the floorof the stiffness of the frame beams to strengthen the frame beam in accordance with thecrack reinforcement reinforcement "super" and stirrup characteristic value of the framestructure anti-seismic collapse capacity. The results showed the structure of the axialcompression ratio on the aseismic capacity greater impact, for7degrees district RCframe structure should have more stringent axial compression ratio limit; with theimprovement of the amplification factor of the column end moment frame structureaseismic capacity some improvement, but to strengthen the role of the floor frame beam,can not be achieved the destruction of the weak beam mode; aseismic ability toinfluence smaller frame beam reinforcement "super" and stirrup characteristic value ofthe structure, in accordance with the specification the specified minimum stirrup ratio tomeet the structural collapse resistance performance requirements. (3) The study on the Xuankou middle school building C and office building Gframe structure earthquake disasters reasons. Incremental dynamic method to calculatestructural collapse resistance the reserve coefficient CMR value, the results showed thatthe office building G CMR value of approximately twice the teaching building C;obtained through static analysis method school building C and office building G supercoefficient and ductility factor, the results showed the ductility factor structure collapseresistance greater impact.(4)7degrees New Group B frame improve collapse resistance design, the buildinghas been built aseismic reinforcement measures. For the Xuankou middle schoolbuilding C, respectively, re-designed in accordance with the to reduce axial compressionratio and improve the fortification intensity method, compared to when fortificationintensity increased to8degrees, structure aseismic capacity has improved significantly.The building has been built to increase the cross-sectional method and Rubber Bearingreinforcement method can significantly improve the ability of anti-structure collapsed, itis recommended that post-disaster needs of hospitals and other important buildingsimmediately put into relief the isolation bearing reinforcement and design.