Numerical Analysis Of Seismic Response Of Subway Shield Tunnel Structures

In recent years, several strong earthquakes at home and abroad, made different degrees ofimpact to underground structures. Seismic performance of underground structures, includeshield tunnel, has caused widespread concern. With a lot of earthquake damage data whichwere accumulated all over the world was analyzed much more thorough, people also come torealize that: the traditional static and quasi-static method had a bit of limitations whenanalyzing the underground structure’s seismic problems. Compared with that, the dynamicfinite element method using the computer assist calculation and analysis have obvioustechnical advantages when doing seismic response analysis of the underground structure.This article based on the formation condition of Guangdong region, use commoncommercial finite element software ADINAsystematically analyzed and researched the shieldtunnel’s seismic response of horizontal and vertical. Specifically including: varies parameters’influences for subway shield tunnel’s seismic response. The parameters include: structure size,intensity of seismic wave, exciting form, intensity of lining and the formation conditions. Inorder to provide a reference and basis for the project seismic design. The main work is asfollows.1. Based on the work of predecessors, systematically generalize and analyze the twoaspects professional literatures which are include the seismic response features ofunderground structure and method of seismic analysis.2. Starting from the soil dynamic constitutive, dynamic response of strata, soil andstructure interaction and Newmark-β solving method, elaborate and analyze the soil-structuredynamic analysis of finite element theory and its implementation laid the foundation for thenumerical analysis.3. Systematically introduce the essence and implementation of structural dynamic finiteelement method’s viscous-spring artificial boundary.4. As the main factors in single stratum and complex formation, comparatively analyzeshield tunnel transverse seismic bidirectional incentive dynamic response. The results showthat shield tunnel’s horizontal and vertical displacements don’t weak with the seismic waveacceleration’s attenuate, they keep a stable vibration modes in a certain period. At bidirectional incentive, within a seismic wave time, structure’s vertical vibration frequency ishigher than the horizontal vibration frequency. The vibration frequency and the maximumdisplacement in single stratum both higher than in the complex formation.5. Build a dimensional finite element model of shield tunnel and surrounding soil,analyze the seismic response of shield tunnel in different conditions. The results show that ingeneral, tunnel seismic response displacement is under2-3cm, the deform is smaller than theground structure. In soft ground or the formation condition change or the formation conditionis complex, tunnel lining may has a abnormal dynamic stress concentration, the result in thestratum interface of different mechanical properties has improved10%-13%than in the singlestratum.