Analysis Of Subway Structures’ Response And The Optimal Control Under Seismic Acition

As one of the most common natural calamities, the earthquake has substantial impact on people’s ordinary life. Unfortunately, China is one of those countries that seriously suffer from the seismic activities in the world. In the past a couple years, the Mainland China has lost billions Yuan and millions of its citizens have been afflicted by the disasters. Lives were deprived; houses were destroyed; farms and livestock were ruined; while stores and vehicles were damaged. The earthquakes have not only caused tremendous losses to people’s lives and properties, but also tortured countless families by disturbing their ordinary life. Therefore, acting as the main transportation in cities, subway plays a significant role in people’s urban life. Since the subway will definitely contribute to easing traffic congestion in the future, it is imperative to ensure the operation is safe and smooth. The researches on subway structures and the quality of earthquake resistance thus are sufficiently significant, which has caused a widespread attention of worldwide scholars.In this article, I have analyzed the reaction of subway structure to earthquakes and the stability of soil. Moreover, I have proposed an optimal controlling program of subway and trains. The main content including:Firstly, This article summarizes the existing theories of the earthquake resistance of underground structures and the fundamental concepts of finite element method; introduces the popular methods applied in dynamic structural modeling analysis of seismic responses; discusses dynamic responses and the stress and strain distributions of the structure under seismic activities; and evaluates the subway structure and the stability of surrounding soil under seismic activities.Secondly, borrowing from large-scale analysis program ANSYS and the finite element numerical analysis, this article focuses on the analysis and the calculation of the subway structural modeling. Modeling analysis, harmonic wave response analysis and the transient response analysis are the three major tools utilized. The conclusion about the stability of the subway structure and the surrounding soil is thus drawn, which helps to better improve and further control the structures of the subway.Thirdly, a model of running trains is established to describe the condition of the subways under the seismic profile. Moreover, the mix H2/H∞controller is designed to successfully take shaking trains under control when earthquake occurs.