The Study Of Vulnerability Analysis Of Existing Buildings Under Eathquake Disaster

With the urbanization level rising, more and more people influx into the town, which has promoted the renovation of old buildings in China. The process of existing buildings' demolition change may have a certain influence on the structure of the existing buildings, such as the changes of columns and beams will change the power transfer path of structures, the demolition of partition will leads to a change in stiffness. This series of changes can affect the resistance of the old buildings under earthquake.Earthquake is a natural phenomenon.With the Indian Ocean plate squeeze the Eurasian plate constantly, it is more likely to occur high intensity earthquake in the central and western regions of our country in future, and we need to maintain a high level of vigilance. How to evaluate the possible seismic risk of damage to lifeline engineering in the region, to avoid the loss of people's life and property, has always been a strategic issue. After earthquake disaster, the damage assessment of the structure plays an important role, which affect the safety of people's live, but this method of assessment is only limited to the disaster relief after earthquake. How to assess the disaster relief before earthquake even can avoid major losses, and it will be another way of thinking of earthquake disasters, which called earthquake hazard loss evaluation.Structure vulnerability study is actually an important part of the design thought based on the performance, is also a certain continue of the design thought based on the performance. The seismic risk analysis results and earthquake station data are used to establish a probability response spectrum in the central and western regions in our country, considering the frequency content and the response spectrum and random phase angle after using the programmed unsteady initial artificial seismic wave, optimize the artificial seismic wave by comparing with standard response spectrum as the external input of structure damage assessment.Make a systematic summary of damage parameter for reinforced concrete frame structure, establish a four typical layer reinforced concrete ductility frame sample structure,then make a dynamic nonlinear analysis calculation, compare the proposed vulnerability recommendations in the study with the other damage parameters, which proved that proposed vulnerability parameters can accurately reflect the actual damage level of structure.Compare the standard of our country with the important earthquake risk assessed software HAZUS2003 system on the classification of the structures, and citing foreign reinforced concrete structures to describe the damage threshold classification corresponding to limit damage level value of the interlayer displacement angle. On this basis, the study puts forward the damage level definition table and limit damage suggested value of the reinforced concrete structure in central and western regions in China.Select typical low-rise reinforced concrete frame structures in the central and western regions in China through an on-the-spot investigation, under the assumptions of the material statistics and part of the gravity loads subject to normal probability distribution, selecting artificial earthquake time history record and combined with the representation of the actual earthquake records, using the dynamic time history method to calculate the dynamic damage and seismic performance in detail for this kind of structure, and gain the vulnerability curve finally.