INVESTIGADORES
PINTO federico
congresos y reuniones científicas
Título:
Seismic demands for deep tunnels and shafts
Autor/es:
FEDERICO PINTO; RICARDO J. ROCCA; PEDRO J. F. HUERTA; CARLOS A. PRATO
Lugar:
Montreal
Reunión:
Congreso; 13th International ISRM Congress; 2015
Institución organizadora:
International Society for Rock Mechanics
Resumen:
The seismic hazard for civil engineering structures is generally defined in terms of deterministic or probabilistic acceleration response spectra at an equivalent rock outcropping. The design of unnels, however, requires the definition of demands in terms of accelerations at ground surface (near the portals) and in terms of both accelerations and velocities at different depths within the alignment. The design near the portals is controlled by inertial effects and is often times impacted by the possibility of slope instability and rockfall, whereas the design at deep sections is controlled by kinematic effects. These effects are accounted for in practice by introducing deformation patterns in the structure that are related to an assumed wavefield, often times ignoring the effect of the structural stiffness in the response. This paper presents a study regarding the definition of seismic demands for different sections of 14-km long tunnel in the Andes (Argentina-Chile), with a maximum overburden of 1750 m in a seismically active region. The tunnel will pass through volcanic massifs mainly composed by andesites and rhyolites. The study includes the definition of spectrum-compatible seismograms, deconvolution, and definition of accelerations and peak particle velocities for different overburden conditions. A kinematic interaction study for a 500-m tall ventilation chimney shaft is also described, where a simple formulation for the interaction analysis is considered in order to more accurately evaluate shear and bending demands.