The Analysis Of Dynamic Characteristic For Big-Span Underground Structure

With the development of the economy, more underground structures was utilized in energy, traffic, defending engineering, etc, its important is more visible. So anti-seismic for underground structures is important both in theoretical research and engineering.Because of all of kinds underground structures was badly damaged in the 1995 Hanshin桝waji earthquake, this article study frame underground structures with the method of dynamic numerical analysis and shaking table test. In the article ,We try to find out the rule of the subway station react to earthquake, analyze the distortion of the structure and get the mechanism of wreck , in order to provide theory to the design of the large underground structures similar to subway station.This article find conclusion as follow:1. the system's natural dynamic characteristic is different from only structure. It's natural frequency is smaller than only structure's, but the camp is larger. The horizontal frequency is accordant, on the contrary ,the vertical frequency is different.2. The distributing of the pressure on the wall like a saddle. The displacement of the wall distribute like a saddle when structure is buried deeply, which is different from shallow-bury-structure.3. The biggest stress exists on the end of the middle column , but it existson the top of the wall. When the structure receive vertical load , middle column appear draw-press stress , especially on the top.4. The vertical earthquake is dangerous to the underground structures.5. The shallow-bury underground structures is more dangerous than deep-bury.