Performance of Bridges during the 2010 Darfield and 2011 Christchurch Earthquakes

摘要: The region in and around Christchurch, encompassing Christchurch city the Selwyn Waimakariri districts, contains more than 800 road, rail, pedestrian bridges. Most of these bridges are reinforced concrete, symmetric, have small to moderate spans (15–25 m). 22 February 2011 moment magnitude ( Mw ) 6.2 earthquake induced high levels localized ground shaking (Bradley Cubrinovski 2011, page 853 this issue; Guidotti et al. 767 Smyrou 882 issue), with damage mainly confined central eastern parts Christchurch. Liquefaction was evident over much part city, lateral spreading affecting spanning both Avon Heathcote rivers. The majority bridge a result liquefaction-induced spreading, only four suffering significant on non-liquefiable sites. Abutments, approaches, piers suffered varying damage, very little observed superstructure. However, amount compared other structural systems. Because some critical infrastructure network sustained substantial extensive traffic disruption occurred immediately following event. This paper presents summary field observations subsequent analyses Canterbury as earthquake. Reference is also made performance 4 September 2010 7.1 Darfield (Gledhill 2011), details progression presented where applicable. motion characteristics for events regional soil conditions first described. We provide descriptions at each selected site compare liquefaction predicted response using situ test data. …