A Liquefaction Hazard Map of the Las Vegas Valley, Nevada

The potential for basin amplification of ground motion from significant seismic sources 100-200 km (62-124 mi.) from the Las Vegas Valley (such as the Death Valley Fault System) and Quaternary faults in the valley could provide sufficient energy to cause liquefaction. Key criteria of liquefiable soils coupled with a shallow groundwater table (less than 15 m (50 ft)) are met at several sites in the Las Vegas Valley. To investigate the extent of the liquefaction hazard, a map was prepared from existing data compiled from geotechnical reports, using screening protocols for liquefaction potential. Geotechnical soils reports for the Las Vegas area were screened to establish a database. The data were compiled with geographical coverage of the valley in mind. Emphasis was placed on areas with favorable surficial geology and groundwater conditions. Once established, the data were evaluated using protocol criteria to ascertain the degree of liquefaction hazard present at the site. The final product has been superimposed on the map base used by the Clark County Building Department for other soil constraints mapping in the Las Vegas Valley. Thus, the liquefaction hazard map can be used as a planning tool to indicate whether site-specific investigations for liquefaction susceptibility are warranted.