Source code for openquake.hazardlib.gsim.vanhoutte_2018

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"""
Module exports :class:`VanHoutteEtAl2018RSD`
"""
import numpy as np

from openquake.hazardlib.gsim.base import CoeffsTable, GMPE
from openquake.hazardlib import const
from openquake.hazardlib.imt import RSD575


[docs]class VanHoutteEtAl2018RSD(GMPE): """ Implements the GMPE of Van Houtte et al. (2018) for significant duration with 5 - 75 % Arias Intensity. doi:10.1785/0120170076. The oscillator duration model has not yet been implemented. """ #: Supported tectonic region type is active shallow crust DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.ACTIVE_SHALLOW_CRUST #: Supported intensity measure types are 5 - 75 % Arias #: significant duration DEFINED_FOR_INTENSITY_MEASURE_TYPES = set([RSD575]) #: Supported intensity measure component is RotD50 DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.AVERAGE_HORIZONTAL #: Supported standard deviation types are total, inter and intra-event DEFINED_FOR_STANDARD_DEVIATION_TYPES = set([ const.StdDev.TOTAL, const.StdDev.INTER_EVENT, const.StdDev.INTRA_EVENT ]) #: Requires vs30 REQUIRES_SITES_PARAMETERS = set(('vs30',)) #: Required rupture parameter is magnitude REQUIRES_RUPTURE_PARAMETERS = set(('mag',)) #: Required distance measure is closest distance to rupture REQUIRES_DISTANCES = set(('rrup', ))
[docs] def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types): """ See :meth:`superclass method <.base.GroundShakingIntensityModel.get_mean_and_stddevs>` for spec of input and result values. """ C = self.COEFFS[imt] mean = (self.get_magnitude_term(C, rup.mag) + self.get_distance_term(C, dists.rrup, rup.mag) + self.get_site_amplification(C, sites.vs30)) stddevs = self.get_stddevs(C, dists.rrup.shape, stddev_types) return mean, stddevs
[docs] def get_magnitude_term(self, C, mag): """ Returns linear magnitude scaling term """ return C["b0"] + C["b1"] * (mag - 6) + C["b2"] * (mag - 6) ** 2
[docs] def get_distance_term(self, C, rrup, mag): """ Returns distance scaling term """ fac = rrup > 100 rmax100 = rrup.copy() rmax100[rmax100 > 100] = 100 fr = C["b3"] * np.log(np.sqrt( rmax100 ** 2 + (np.exp(C["b4"] + C["b5"] * (mag - 6))) ** 2)) + \ fac * ( C["b6"] * np.log(np.sqrt( rrup ** 2 + (np.exp(C["b4"] + C["b5"] * (mag - 6))) ** 2)) - C["b6"] * np.log(np.sqrt( 100 ** 2 + (np.exp(C["b4"] + C["b5"] * (mag - 6))) ** 2)) ) return fr
[docs] def get_site_amplification(self, C, vs30): """ Returns linear site amplification term """ return C["b7"] * np.log(vs30 / 1000)
[docs] def get_stddevs(self, C, nsites, stddev_types): """ Returns the standard deviations """ stddevs = [] zeros_array = np.zeros(nsites) for stddev in stddev_types: assert stddev in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES if stddev == const.StdDev.TOTAL: stddevs.append(np.sqrt(C["tau"] ** 2. + C["phi"] ** 2.) + zeros_array) elif stddev == const.StdDev.INTER_EVENT: stddevs.append(C["tau"] + zeros_array) elif stddev == const.StdDev.INTRA_EVENT: stddevs.append(C["phi"] + zeros_array) return stddevs
COEFFS = CoeffsTable(sa_damping=5, table="""\ imt b0 b1 b2 b3 b4 b5 b6 b7 tau phi rsd575 -1.7204 0.2272 0.0967 0.8870 2.7641 0.5777 1.1700 -0.1413 0.2270 0.4163 """)