Source code for openquake.hazardlib.gsim.geomatrix_1993

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2014-2022 GEM Foundation
#
# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake. If not, see <http://www.gnu.org/licenses/>.

"""
Module exports :class:`Geomatrix1993SSlabNSHMP2008`.
"""
import numpy as np

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


def _compute_mean(C, mag, ztor, rrup):
    """
    Compute mean value as in ``subroutine getGeom`` in ``hazgridXnga2.f``
    """
    gc0 = 0.2418
    ci = 0.3846
    gch = 0.00607
    g4 = 1.7818
    ge = 0.554
    gm = 1.414

    mean = (gc0 + ci + ztor * gch + C['gc1'] +
            gm * mag + C['gc2'] * (10 - mag) ** 3 +
            C['gc3'] * np.log(rrup + g4 * np.exp(ge * mag)))

    return mean


[docs]class Geomatrix1993SSlabNSHMP2008(GMPE): """ Implements GMPE for subduction intraslab events developed by Geomatrix Consultants, Inc., 1993, "Seismic margin earthquake for the Trojan site: Final unpublished report prepared for Portland General Electric Trojan Nuclear Plant", Ranier, Oregon. This class implements the equation as coded in the subroutine ``getGeom`` in the ``hazgridXnga2.f`` Fortran code available at: http://earthquake.usgs.gov/hazards/products/conterminous/2008/software/ Coefficients are given for the B/C site conditions. """ #: Supported tectonic region type is subduction intraslab DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.SUBDUCTION_INTRASLAB #: Supported intensity measure types are spectral acceleration, #: and peak ground acceleration DEFINED_FOR_INTENSITY_MEASURE_TYPES = {PGA, SA} #: Supported intensity measure component is the geometric mean of #: two horizontal components DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.AVERAGE_HORIZONTAL #: Supported standard deviation type is only total. DEFINED_FOR_STANDARD_DEVIATION_TYPES = {const.StdDev.TOTAL} #: No site parameters required REQUIRES_SITES_PARAMETERS = set() #: Required rupture parameters are magnitude and top of rupture depth REQUIRES_RUPTURE_PARAMETERS = {'mag', 'ztor'} #: Required distance measure is rrup (closest distance to rupture) REQUIRES_DISTANCES = {'rrup'} # Shear-wave velocity for reference soil conditions in [m s-1]) REQUIRES_SITES_PARAMETERS = set() DEFINED_FOR_REFERENCE_VELOCITY = 760.
[docs] def compute(self, ctx: np.recarray, imts, mean, sig, tau, phi): """ See :meth:`superclass method <.base.GroundShakingIntensityModel.compute>` for spec of input and result values. """ for m, imt in enumerate(imts): C = self.COEFFS[imt] mean[m] = _compute_mean(C, ctx.mag, ctx.ztor, ctx.rrup) sig[m] = C['gc4'] + C['gc5'] * np.clip(ctx.mag, None, 8.)
#: Coefficient table obtained from coefficient arrays and variables #: defined in subroutine getGeom in hazgridXnga2.f COEFFS = CoeffsTable(sa_damping=5, table="""\ IMT gc1 gc2 gc3 gc4 gc5 pga 0.0 0.0 -2.556 1.45 -0.1 0.1 1.1880 -0.0011 -2.6550 1.45 -0.1 0.2 0.722 -0.0027 -2.528 1.45 -0.1 0.3 0.246 -0.0036 -2.454 1.45 -0.1 0.5 -0.4 -0.0048 -2.36 1.45 -0.1 1.0 -1.736 -0.0064 -2.234 1.45 -0.1 2.0 -3.3280 -0.0080 -2.107 1.55 -0.1 3.0 -4.511 -0.0089 -2.033 1.65 -0.1 """)