Research On Earthquake-induced Differential Settlement And Its Influencing Factors Based On OpenSees

According to the origin of seismic subsidence, the seismic subsidence can be defined as the additional settlements of soil or structure caused by earthquake. Seismic subsidence, especially the earthquake-induced differential settlement on soft foundation, frequently leads to the tilt and crack of structures and even destroys structures, roads, and lifeline engineering. About the seismic hazard caused by subsidence, researchers and engineers have learnt increasingly more from the past earthquakes. Additionally, seismic subsidence is becoming a hot topic among researchers.Nevertheless, due to the lack of the field data about seismic subsidence, the development of research on this field is limited. It is necessary to build an analytical model for soil-structure system under earthquake loadings which can be applied to simulating the process of the formation and propagation of seismic subsidence in order to predict the hazard level on a given field or to analyze the factors which may affecting the seismic subsidence.In the thesis, a reliable calculating model for seismic subsidence is built with OpenSees, an FE analysis framework, based on a series of seismic data investigated by researchers throughout the world. Moreover, after verifying the reliability of the model, analysis on factors which have an impact on seismic subsidence and earthquake-induced differential settlement is undertaken with the model.The main salient points to be completed can be outlined:1. In order to understand the mechanism of seismic subsidence and earthquakeinduced differential settlement, it is indispensable to collect and summarize relative information. Besides, research orientation is refined from the data collected.2. An FE subsidence calculation model needs to be built with OpenSees. By means of numerical experiment, scales, boundary conditions, soil constitutive relations, patterns of static and dynamic loadings are defined.3. The reliability of the model is verified by comparing the computing result with factual data researchers have investigated in past earthquakes.4. The way site factors affect the subsidence is analyzed. By analyzing the computing results of selected site conditions in line with seismic codes, the impact of site factors is initially revealed.5. The way ground motion factors affect the subsidence is analyzed. By analyzing the computing results of selected ground motions tuned with the peak ground accelerations in seismic codes, the impact of ground motion factors is initially revealed.6. The way loading factors affect the subsidence is analyzed. By analyzing the computing results of a series of different loading patterns, the impact of loading factors is initially revealed.7. The research outputs are summarized and further researches is prospected in the research of seismic subsidence and earthquake-induced differential settlement.