EVALUATION OF SEISMIC PERFORMANCE OF RAMP TUNNEL STRUCTURE DURING LEVEL-2 EARTHQUAKE BY MASSIVE 3D NUMERICAL COMPUTATION
Abstract
Quasi non-linear 3D FEM earthquake response analysises with level-2 earthquake are conducted for a ramp tunnel structure of Tokyo metropolitan express way central circular line the Yamate tunnel. Large-scale numerical computation with solid elements is highly required for examination of seismic response of large tunnel in case of level-2 earthquake. The results are obtained as follows: i) In level-2 earthquake, stress concentration in ramp tunnel becomes great near geological interface between two layers of high impedance contrast. ii) The response is not obtained as a superposition of two-dimensional responses which is an assumption in conventional design methods because the distribution of displacements in the direction of tunnel axis at cross-section of ramp tunnel structure near geological interface does not linearly distribute. iii) Evaluation of stress in addition to section force is desirable for the correct evaluation of the three-dimensional response of tunnel structure.
- Publication:
-
Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE))
- Pub Date:
- 2012
- DOI:
- 10.2208/jscejseee.68.I_830
- Bibcode:
- 2012JSCSE..68I.830Y