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1.8 deg15 cmGround cracking due to lateral displacements▲▲Figure 11. Liquefaction-induced differential settlement and sliding of building in the CBD (24 March 2011; S43.52878 E172.64252).NLiquefaction-inducedsediment ejecta29 cm 18 9 6 5 4 0▲ ▲ Figure 12. Building undergoing significant liquefaction-induced differential settlement due to part of it being founded on the liquefactionfeature in this area (24 March 2011; S43.52878 E172.64252).not appear to settle. Starting from its northern edge and proceedingsouth, the differential settlement is 1 cm for the firstspan, 1 cm for the second span, then 3 cm, 9 cm, and 11 cm,respectively, for the final three spans. This results in an overalldifferential settlement across the structure of 25 cm, with20 cm of it occurring across the two southernmost spans. Astrong tie beam 0.6 m wide × 1.2 m deep was used between thefootings for the first two northernmost spans, whereas the tiebeams between the footings for the remaining spans were only0.3 m wide × 0.45 m deep. This foundation detail, togetherwith the fact that the observations of liquefaction were mostsevere at the southeast corner of the building and diminishedacross the footprint of the building toward the north, led tosubstantial differential settlements and pronounced structuraldistortion and cracking. Both buildings were considereduneconomical to repair after the 22 February 2011 earthquake.The building shown in Figure 11 has been demolished and thebuilding shown in Figure 12 will be demolished.Performance of Adjacent Structures—Town Hall AreaThe Christchurch Town Hall for Performing Arts, designed bySir Miles Warren and Maurice Mahoney and opened in 1972,is located within the northwest quadrant of the CBD, with themeandering Avon River to its immediate south. It is a complexfacility comprising a main auditorium (seating 2,500) withadjoining entrance lobby, ticketing, and café areas. Furtherextensions provide a second, smaller auditorium, the JamesHay Theatre (seating 1,000), and a variety of function roomsand a restaurant. The structures are supported on shallow foundationsexcept for the kitchen facility, which was added later.Seismological Research Letters Volume 82, Number 6 November/December 2011 901