Safety Analysis Of Nearby Building Structure Under Collapse Vibration In Blasting Demolition

With development of the economy, engineering of demolishing building by blasting in the city has becoming more and more common, especially the high-rise construction fast development. Though blasting procedure brings the high economic efficiency and the project blasting enterprise while develops vigorously, it has many problems, such as the blasting vibration effect, the air blast effect, the demolition flies the stone, the noise, the harmful gas and so on. Therefore, the topic regarding the blasting earthquake effect research as well as the demolition safety control aspect receives the widespread attention. This article has conducted the research to dynamic response of frame construction, and has made the appraisal about its security under the blasting effect.This paper has consulted massive domestic and foreign literature about the blasting function to the house, and has analyzed the present domestic and foreign research present situation in detail and the insufficiency, and aimed at the question which the paper had to solve to study the related theory knowledge. The theory includes producing mechanism, the attenuation law and the characteristic of surface vibration during the process of demolition blasting. It has analyzed relational model, as well as the step and the principle of the construction dynamic response using finite element method.This paper mainly utilizes non-linear finite element method to establish the finite element three dimensional model of frame house dynamic response, and established the finite element dynamic computational procedure in order to obtain the house dynamic response situation. This paper selects the 2# and 3# test point blasting seismic wave in a removing of WuHan Market and the routine earthquake wave and inputs frame house. This paper carries out in four seismic wave input cases. The first case only inputs the north and south direction earthquake acceleration, the second case is simultaneously inputs the north and south direction acceleration and the vertical earthquake acceleration, the third case only inputs the east and west direction earthquake acceleration, the last case three dimensional earthquake acceleration, it carries on the dynamic analysis of several kinds of situations in houses, and obtains information of structure force, structure distortion. Analysis and comparison are performed to make the appraisal of the house security under the blasting effect. Below the paper draws the conclusion: (1) There is heavy difference of the structure under the function of blasting earthquake wave and routine earthquake. Unless analyze time history, it could go on the overall assessment of safety. (2) The characteristic of blasting vibration is deferent from that of natural shock That is, its velocity is higher, its frequency is lower and its acting time longer. The dynamic response of the structure reflects is not very big. (3)Demolition seismic wave has randomness, so we need consider vertical earthquake and horizontal earthquake effect.