New Liquefaction Requirements and Associated Peak Ground Acceleration Maps

摘要

New provisions for computing peak ground acceleration (PGA) for soil liquefaction and stability evaluations have been introduced in Section 11.8.3 of the 2010 NEHRP Seismic Provisions and the ASCE 7-10 standard. The PGA provisions consist of maps of the Maximum Considered Earthquake (MCE), geometric mean, horizontal component, bedrock PGA, plus a site-coefficient (Fpga) table to convert the bedrock PGA value to one corresponding to another site class. Of particular note is the requirement that liquefaction must now be evaluated for the MCE, rather than the design earthquake, as currently required in the 2006 International Building Code (IBC) and ASCE 7-05.