The Study Of Single-Span-Frame’s Reinforcement And Reconstruction Basing On The Seismic Performance Analysis

China is a volcanic earthquake country in the world whitch occupy one 5 of the world’s population.Earthquake is a strong natural geological disasters.The characteristics of the earthquake is difficult to predict, huge destructive power, having a great influence for people’s spirit and material life.The earthquake has become the worst natural disasters that could destroy human’s life and property safety.As a result,how to reduce the earthquake damage this problem is more and more get the attention of the people all over the world.The earthquake can make a city in ruins immediately.The horror of the Wenchuan earthquake in 2008 is still let every person remember.Wenchuan and surrounding cities suffered a catastrophic that made moving people displaced.And a large number of casualties is caused by the houses collapsing in the earthquake.We could find from the survey after the earthquake that a large number of early school, apartment, auditorium, etc. are in the form of single span frame structure witch is insufficient, lack of the seismic line. Once the pillars in the earthquake damage can lead to destruction of development rapidly.As a result,it lead to the collapse of the whole structure.The process time is short and the damageis extent.The chance to escape in the earthquake was greatly reduces.As a result,it lead to serious casualties. So it’s crucial to make seismic design for new buildings and make reinforcement renovation of existing buildings when they are not accord with standard of anti-seismic.China’s 10 edition of the code for seismic design of buildings article 6.1.5 and 09 edition "aseismatic appraisal standard" have clear regulation.Frame structure should not be in the form of single span. A buildings and B buildings,C buildings that not higher than 24M should not be in the form of single span. The buildings do not meet the provisions should be redesigned for seismic strengthening。Although the new rules put forward relevant norms. But there is no definite stipulation what method is most appropriate.Through the seismic strengthening design of a typical cantilever end of the single span structure building,this article use three different reinforcement methods.Firstly, through adding the cantilever end frame column, we change the original structural form to double-spans’ structure. Secondly,though adding short-limb shear walls,we change the original structural form to shear-wall-frame structure.Thirdly,we can add steel braces in the same part as the second method.We were on the original structure and the reinforcement scheme is changed and the floor is considered factors under severe earthquake response spectrum and Pushover analysis by using the finite-element software ETABS program.Studies have shown that:these three kinds of reinforcement scheme all could reduce the natural cycles of the original structure and improve the structure of the reverse effect, at the same time,they could increase the lateral stiffness of the original structure Reduced the original structure horizontal displacement and displacement angle between the layers.Increasing the number of shear wall have the most significant effect.But it will increase the interlaminar shear structure.And impact on the Y direction is not obvious.Through observing the plastic hinge distribution and the inter layer displacement.Through the angle of the models in the elastic-plastic stage,we could know that the original structure is easy to suffer from the Hinge mechanism damage,witch is not meet the seismic concept design principles.And the elastic-plastic inter layer displacement Angle overrun.This does Do not conform to the requirements of the specification. The three kind of reinforcing scheme has not been a column hinge mechanism.At the same time,they have the function to protect the original structure from damage.And effectively reduce the original interlayer displacement Angle of structure.The reinforcement scheme has a good seismic performance.And they introduced in the process of the nappe of the program that should be aware of the weak links.