Full 3D seismic analysis of a long-distance water conveyance tunnel

A full three-dimensional seismic analysis is presented which is conducted on a newly built double-line shield tunnel used for water supply in the city of Shanghai. Comprehensive details in establishing such a large-scale analytical model are firstly presented, including determination of the control axis and finite element mesh size, nonlinear constitutive model of soils, load and boundary conditions, and definition of nonlinear contact surface accounting for soil–structure interaction. In view of its large computing scale, a high-performance supercomputer is used and an explicit central difference method which is provided by LS-DYNA is employed to accomplish the numerical analysis successfully. Seismic behaviour of the tunnel is thoroughly investigated regarding responses of displacement, segment internal stress and ovality of tunnel cross-section. Then a global evaluation of the seismic safety is provided based on numerical results. Further study on the effects of input ground motions shows that the given ground motions affect the value and the location of structural stresses as well as deformation type. A mitigation method fitting flexible joints is also studied and it is proved to be effective, however, especial attention should be paid to the decrease of structural stiffness in design.

Language

  • English

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  • Accession Number: 01497387
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 30 2013 3:00PM