Influence Of Seismic Performance Of The Stairs And The Interaction Framework

Occurred in China in 2008 Wenchuan earthquake damage showed stairs vertical transport corridors of the building, is the only way to evacuate people in the earthquake, but its role is not obvious in the earthquake, and even damage to the structure was first even blocking the stairs because of damage needs to survive fleeing earthquakes, some scholars in a series of studies on the stairs, make recommendations and provide some possible solutions. In this context, this paper analyzes the overall structure of the stairs, model building using structural analysis software SAP2000 analysis of the impact on the dynamic characteristics of the framework of the stairs, but also on the framework for analysis does not consider the stairs and proposed measures to minimize adverse impacts, and analyzes the overall structure and model ladder beam disconnected. Then its modal analysis, response spectrum analysis. The main task of this paper is as follows:(1) the description and summary destruction of earthquake damage and the status of research in the form of stairs at home and abroad;(2) In SAP2000 were established there, without stairs frame structure, modal structures,response spectrum analysis, two models of base shear, the interlayer displacement,comparative analysis with and without a staircase structure model for the overall structure on seismic performance, structural analysis software SAP2000 are considering stairs and do not consider the structure of stairs Static and dynamic analysis;(3) the use of SAP2000 build stairs with the main frame structure separate staircase column disconnected model and platform bench plate girder sliding support office is located off the bench plate model, the reaction of the two models and has a staircase structure model Spectral analysis compared the stairs in the form of structural changes observed adverse effects on the overall reduction is valid, consider how to reduce the adverse effects on the structure of the stairs, and study and propose solutions;(4) to be resilient when under real history analysis of seismic waves, compared to four structural model: were no stairs, stairs, stair column disconnect type, bench plate off type,obtained by model base shear interlayer displacement angle and other parameters studiedcomparative analysis of internal forces and deformation of each model to get the difference in the actual seismic waves and the response spectrum method. The above model time-history analysis and response spectrum analysis, time history analysis and comparison of the differences between and response spectrum analysis;(5) through the analysis of the forces in SAP2000 member stair staircase structure model,summarizes the characteristics of the staircase member force under the seismic action to reduce the adverse effects of the staircase gives the whole structure of the program. Analysis to draw relevant conclusions, some suggestions as reference depending on the model comparison staircase design.The main conclusions are as follows:(1) The analysis in this paper shows that the stairs to the cycle frame structure, modes, the base shear are not greater impact be ignored;(2) under the earthquake, the impact of the stairs on the overall stiffness of the frame in the Y direction, that is along the direction of bench plate is significantly greater than the stiffness of the X-direction and the direction perpendicular to the bench of the plate;(3) Under the seismic force, between the member and the overall structure of stairs strong interaction is also closely related to the destruction of the whole staircase structure traditional staircase design method is very reliable, could be improved;(4) to take corrective measures against the stair member bench soon separate panels and the main structure, will be separated from the main structure staircase column staircase to reduce the adverse impact on the overall structure of a certain role;(5) ladder column disconnected structure is greater than bench plate off base shear structure;(6) ladder column disconnected structure increases the overall stiffness of a more significant effect, while bench plate off of the overall stiffness of the structure is less affected results.Design of stairs advice:(1) The internal force analysis of the stairs members found that under horizontal seismic action, bench boards of axial force and shear larger bench during the board design should be double pass along the longitudinal length of reinforcement to form a double bidirectionalreinforcement layer configuration;(2) ladder column is short columns, and a short column of stiffness under horizontal earthquake than other normal column absorb greater levels of force, cracking caused by overloading of the bar shear stress, shear failure To avoid premature failure of stair post, it is recommended that the entire length of the column in the stirrups encryption;(3) If the inter-frame structure separate from the main structure of the staircase and the design of the vertical structure of the same size should be treated differently stairs, not only by stairs span of bench plate design their own design conditions, should be bench plate as an axis to force members to consider the longitudinal bench plate should be reinforced through a long double.