The Effect Of Cast-in-place Slab On Strong Column-weak Beam Yield Mechanism Of RC Frame Structure

Reinforced concrete frame structure is widely used in various building stru cturesin our country. In all the previous earthquakes, the reinforced concrete framestructures are prominently damaged. It s of great realistic significance to study theseismic performance of the reinforced concrete frame structure. High anti-seismicperformance of structure is guaranteed by the design rule of Strong column-weakbeam. However, a lot of reinforced concrete frame structure buildings don t achievethe goal of strong column-weak beam in most earthquakes. There are many factorsaffecting the goal to achieve, in which the slab is an important factor. Therefore, thisthesis is organized around the important factor as follows:(1) In the current design, the slab and beam are designed separately, and theimpact of plane external stiffness of the floor on RC frame structure isn t consideredreasonably. Through the analysis of different elements to simulate the floor in thisthesis, the plane external stiffness of the floor can t be ignored.(2) Through the pushover comparative analysis of the established models, thisthesis investigates the impact of different types of slab on the seismic performance ofRC frame structure. By changing the thickness and concrete strength of the slab, thethesis uses the capacity curves, the lateral displacement and the plastic hingedistribution to investigate the seismic performance of the RC frame structure. And bycontrasting the unidirectional plate and bidirectional plate model, the effect ofdifferent plate spans on structural seismic performance is also investigated. A largenumber of analysis shows that the current code can not reasonably consider the effectof slab by amplifying the beam stiffness alone, and some recommendations are givenabout the beam stiffness amplification.(3) Pushover and nonlinear dynamic analysis method are applied to analyze theseismic performance of RC frame structure under the action of multiple factors andwith the floor or not. Meanwhile, the adverse effect exerted by oblique seismic actionis summarized from the theoretical formula derivation. The results demonstrate thatwith various axial compression ratios and moment magnifying factors of columns, theseismic performance of the structure will be degraded when the influence of the flooris taken into account. Moreover, the increment of the values of axial compressionratios and moment magnifying factors with the floor exceeds that without the floor. Earthquakes input along the principal axis can realize the strong column-weak beamof the structure. By taking the floor into account, the influence exerted by the actionof oblique earthquake and other factors on the structure will be more harmful.