Study On Evaluation Index For Safety Of Engineering Structures Under Environmental Vibrations

With the development of the societies and cities, the traffic is becoming busier and busier and the citizens are provided with various ways of transportation while a huge amount of projects are under construction. All these activities will bring vibrations to ground and structures. These environmental vibrations, which reach certain intensities, will make residents uncomfortable, make instruments work abnormally and cause fatigue damage even failure to the structures. The evaluation standards of environmental vibrations are now urgent need to further study as its immaturity at home and abroad.In this thesis, dynamic analysis method is used to calculate the maximum inter-story shear force of a six-story frame structure. Then, the correlation between that with the maximum acceleration, velocity and displacement of ground horizontal vibrations are analyzed respectively, which is hoped to provide a reference for vibration absorb design and criteria making. The main contents are as follows:1. The related evaluation criteria and standards as well as the problems existed for engineering structures under environmental vibrations were collected and collated.2. Based on the least square method, program has been made in Matlab to process the measured ground vibration signals by dispelling the noise and disturbance mixing in the signals, which effectively obtained the actual vibration signals.3. Dynamic method has been used to analyze a six-story frame structure under the ground vibrations mentioned above. Based on the analysis, the correlation between the maximum inter-story shear forces of structure with the maximum acceleration, velocity and displacement of ground horizontal vibrations were studied respectively, with the result that the inter-story shear force has the best relativity with ground velocity and the worst with ground displacement by comparing the correlation coefficients.This study has a certain reference value for establishing and improving evaluation criteria for engineering structure under environmental vibrations in China.The research work presented in this thesis is supported by the National Natural Science Foundation of China with the granted number 50779034.