الفهرس 
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Abstract
Hyogo-Ken N anbu Earthquake of january 17th 1995 caused serious damage and collapse to several large-scale underground structures in south of Hyogo Prefecture, Japan. Areinforced concrete rectangular suway tunnel completely collapsed, while serious cracks occurred in several other common ducts and shield tunnels. Although such damage seems to be accepted structurally (expect the collapsed tunnel), however most of those cracks were accompanied with leakage of water. As a result, some of the lifelines became non-serviceable for a considerably long time. Such situation is not accepted from the functionality point of view. Revising the current seismic design method of large-scale underground structures confirms the necessity of improving it, since it is mainly concerned with the aseismic elastic design under low-level ground motions.Consequently, under high-level ground motion some assumptions are no longer reliable. Main assumptioms required to be improved are : (1) Estimation of the stiff layer that represents the base rock, since some shield tunnels were badly damaged although theyare constructed in such layers.. (2)Idealization of ground rigidity specially in case of ground layers with different shear vibration characteristics . (3) The consine-distribution of ground displacements. (4) The mathematical formulation must be used on the inelastic properties of the structure-ground system. (5) Consideration of the influence of various
In this disertation, there are two main objectives. The first one is to clarify the faillre mechanism of the collapsed tunnel, for which a 2D finite element computer program for seismic response analysis of the transverse direction of the RC rectangular tunnel was developed taking account of material and geometrical nonlinearity and dynamic soil-structure interaction. A new finite element inelastic beam model was derived, taking account of the change of dimensions and reinforcement between the two ends of the beam, concrete and /or reinforcing steel yielding, concrete cruching, reinforcing steel faillur, as well as shear faillure in concrete and shear reinforcement. The second objective is to improve the current seismic design methodcof shield tunnels in the transverse direction. For this purpose . For this porpose, an intensive study on shield tunnels with and without secondary lining was performed.This study ranged from elastic to inelastic analysis under low to high-level ground motions. Anew elastic inelastic curved beams-segment joints- interaction springs finite element model was utilized. Severalnew concepts were proposed and developed, the most important are : (1) In case of elastic analysis, the formulations for each mode of vibration were based on Fourier expansion and Bessel functions, and the final response was obtained by mode superposition. (2) A trilinear model for reinforcd concrete shield tunnels. (3) An inelastic model for segment joints of joints of shield tunnels. (4) Simple formulate for for estimating the tunnel forces taking the inelastic properties of the tunnel-ground system into account. (5) Propsing and outling a method for improving the current seismic design methods of shield tunnels in the transverse direction.