Inhalt des Dokuments
Numerical Modeling of Foundation Deformation due to Fault Rupture
Fugro Sial Istanbul
Fugro Consult Germany
In general, it is important to try and locate the foundations of critical structures away from known faults and many seismic codes prohibited construction in the immediate vicinity of seismically active faults establishing minimum setbacks from the faults. But for long structures such as bridges, tunnels and pipelines, such requirements have often been impossible to respect. Moreover, past and recent earthquakes have revealed that survival of structures on top of a fault is not impossible ― even when fault displacements are large.
This paper presents a case study of bridge foundation design that incorporates the consequences of fault deformations passing through the foundation. Recent research efforts combining field studies, centrifuge model testing, and numerical modeling have resulted in the development of a validated methodology for analysis and design of foundation–structure systems against surface fault rupture. This methodology is applied in order to evaluate the demands on a bridge foundation generated by fault rupture.
Finite element analyses are performed that model the free field fault rupture propagation to the ground surface of the fault. The free field fault rupture propagates trough the soil all the way up to the surface passing through the foundation location. Consequently, the foundation elements are introduced in the finite element model and the fault rupture is simulated again. The demands on the foundation generated by the fault rupture are evaluated.