Parameters Affect The Rigidity Of The Frame Structure Floor

A deep beam model with spring bearing is given, based on the analysis of middle frame of frame and shear wall structure ground floor, which is sensitivity to floor rigidity. Comparing rigid assumption to elastic assumption, shear error of frame is worked out, which is index of floor rigidity. Conclusions are drawn that floor rigidity is independent of earthquake intensity and the most effect factor to floor rigidity is floor length to width ratio. To enhance floor rigidity, not means to increase floor thickness. With all the building shape and location of anti-shear member known, shear error can not be limited within 8% compared floor rigid assumption to elastic assumption.Floor rigidity has relations not only to floor stiffness, but also to stiffness and location of anti-shear member. Neither floor length to width ratio nor stiffness ratio of floor to shear wall should be the guild line of rigid floor.In this paper, for the first time, floor stiffness is denoted as shear stiffness, which reflects the influence of floor length to width ratio more effective than floor bend-shear stiffness.According to the prevailing design method, that is, frame and shear wall structures be analyzed on the assumption of rigid floor and then adjusted in the light of criterions, we give an safety analysis. Conclusions are drawn that structure is safe when the ratio of floor length to width is less than 4, while unsafe when the ratio is larger than 4. Now that structure design condition is better than before, suggestion is given that all frame and shear wall structures should be analyzed on the assumption of elastic floor.