FIGURE B9: NON MAGNITUDE-WEIGHTED 2500-YEAR SA (1.0 S) DEAGGREGATION FOR MARTHA HILL MINE FOR CLASS B ROCK, VS30 = 600 M/S TABLE B10: ESTIMATED MEAN MAGNITUDES FOR 2500 YEAR RETURN PERIOD SPECTRAL ACCELERATIONS Intensity Parameter Mean Magnitude (Mw) PGA 6.9 SA(0.5s) 7.0* SA(1.0s) 7.3* *Visually estimated from GNS 2017 deaggregation plots (Figures B7 and B8) B7. CO-SEISMIC DEVIATORIC DEFORMATIONS Co-seismic deviatoric (shear) deformation of slide masses within the embankment are estimated using the method of Bray and Macedo (2019) “Procedure for Estimating ShearInduced Seismic Slope Displacement for Shallow Crustal Earthquake”. The method is based on a fully coupled 1-dimension idealisation of slide mass response with displacement accumulated on the slide surface when the felt horizontal acceleration exceeds the pseudo-static yield acceleration of the slide mass. Inputs and estimated potential displacements are summarised in Table B11. Estimation of the period (Ts) of the slide mass depends on the geometry of the mass. A relationship of 2.6H/Vs is applied, where H is the overall height of the slide mass and Vs is the average shearwave velocity in the slide mass.
RkJQdWJsaXNoZXIy MjE2NDg3