Calculation And Analysis Of The Whole Frame Structure With Staircase During Earthquake

Staircase structure,as the vertical channel of the structure,its importance is of self-evidence.However in previous earthquakes.the researchers discovered that in the situations that many main body structures have been performing well,the staircase structure has been encountered devastative destruction.The staircases which were supposed to play the role of help people escape,did not perform their proper functions in face of natural disasters.At the same time, owing to the existence of the staircase structure,the main structure's stiffness in the direction of the staircase is reinforced,which,under the earthquake, can also strengthen the internal force of the main components that connected the staircases,and finally causes the destruction.To the building structure, the influence is also very great.The paper uses the SAP2000 ( finite-element-analysis soft) to study the load-carrying capacity of two group models.One of group models is the staircase placed in the centre of the structure, which contain five independent models. One is M-1 model (without staircase) , which considers the design load at the present PKPM procedure; Two is M-2 model (without staircase), which is the opening in the staircase room ; Three is M-3 model , which contains staircase and without flat pallet; Four is M-4 model, which designs at the condition of actual structure, such as staircase, flat pallet, construction column of stair case room; Five is M-5 model , the construction columns of which increase 300mmX300mm comparing to M-4 model. Through the models result , we find the displacement decreases, the stiffness of Y direction ( parallel direction of staircase) is greater than X direction (vertical direction of staircase); the shear(X direction/ direction), moment (X direction/Y direction) of columns among staircase room increases to 1.5/3,1.1/1.6 times respectively as compared with M-1 modell; the force, shear, moment of constructinal columns among staircase is 0.71,0.73,0.3 times smaller than the maximum corresponding internalforce of M-1 model, it demonstrates constructinal columns are weak link to resist earthquake and should consider the whole structure with stair.in the model..The other group is the staircase placed in the local part of the structure, which contain two models. One is N-4 model, which designs at the condition of actual structure, such as staircase, flat pallet, construction column of stair case room; Two is N-5 model, the construction columns of which increase 300mmX300mm comparing to N-4 model.Through the models result , we find the displacement increases, the stiffness of Y direction ( parallel direction of staircase) is greater than X direction (vertical direction of staircase), the shear(X direction/ direction), moment (X direction/Y direction) of columns among staircase room increases to 1.5/2.9,1.1/1.5 times respectively as compared with M-1 modell; the force, shear, moment of constructinal columns among staircase is 0.69,0.41,0.16 times smaller than the maximum corresponding internalforce of M-1 model, it demonstrates constructinal columns are weak link to resist earthquake should consider the whole structure with stair.in the model..