Rock slope response to strong earthquake shaking

摘要: The 2010–2011 Canterbury earthquakes triggered many mass movements in the Port Hills including rockfalls, debris avalanches, slides and slumps, associated cliff-top cracking. most abundant with highest risk to people buildings were rockfalls avalanches sourced from up 100 m high cliffs inclined at angles >65°. Cliffs lower than 10 m height generally remained stable during strong shaking, only isolated release of a few individual boulders. We used site-specific data investigate factors that controlled response main sequence, adopting two-dimensional finite element seismic site stability modeling was calibrated using field observations measurements. Observations assessed show taller experienced larger amounts permanent displacement produced volumes smaller cliffs. Results indicated mean KMAX amplification ratio for all sites under study 1.6 (range 1.1–3.8). Field numerical results, however, shaking does not necessarily increase linearly increasing cliff height. Instead, our results accelerations are amplified mainly due impedance contrasts between geological materials, corresponding where differences rock shear wave velocity exist. resulting acceleration strength control stability. However, amount slope volume leaving varied sites, geometry strength.