HR: 1400h
AN: S33B-06    [Abstracts]
TI: Seismic Microzonation of the City of Cali (Western Colombia)
AU: * Dimate, C
EM: mcdimatec@unal.edu.co
AF: Univ. Nacional Colombia, Ciudad Universitaria, Dept. Geociencias, Bogota, Colombia
AU: Romero, J
EM: jromero@ingeominas.gov.co
AF: Ingeominas, Diag. 53 No. 34-53, Bogota, Colombia
AU: Ojeda, A
EM: a_ojeda@kma.com.co
AF: Ingeominas, Diag. 53 No. 34-53, Bogota, Colombia
AU: Garcia, J
EM: jesusg@ingeominas.gov.co
AF: Ingeominas, Diag. 53 No. 34-53, Bogota, Colombia
AU: Alvarado, C
EM: calvarad@ingeominas.gov.co
AF: Ingeominas, Diag. 53 No. 34-53, Bogota, Colombia
AB: The city of Cali is located in the western margin of the Cauca Valley in the flat area between the Western and Central cordilleras of the Colombian Andes, at 70 km east of the Eastern Pacific Subduction Zone. Even though present seismic activity associated with nearest faults is low, historical records demonstrate that earthquakes have caused damage in the city going up to intensity VIII (EMS). Those earthquakes have had origin on diverse sources: the intermediate-depth Benioff zone, near and far continental crustal faults and the Pacific Subduction Zone. Taking into account the location of the city and the seismologic history of the region, neotectonic and seismological studies extending over a region of about 120000 km2 were required to compute seismic hazard. Construction of the geotechnical model of the city included detailed geological mapping, geophysical profiling, single station ambient vibration essays and the deployment of a 12-stations accelerographic network. Geotechnical properties of the soils were determined by mechanical perforations, CPTU (piezocone) and CPT (static penetration) essays, flat plate dilatometer (DMT) tests and down-hole essays which were complemented in the Lab by analysis of consolidation and static and cyclic three-axial essays. As a result, ten geotechnical zones were outlined and characterized. Finally, expected ground motions were calculated at 39 sites in the city using numerical modeling methods.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Seismology [S]
MN: 2007 Joint Assembly