Source code for openquake.hazardlib.gsim.megawati_pan_2010

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2014-2022 GEM Foundation, Chung-Han Chan
#
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# 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.
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"""
Module exports :class:`megawatipan2010`.
"""
import numpy as np
from scipy.constants import g

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


def _get_magnitude_scaling(C, mag):
    """
    Returns the magnitude scaling term
    """
    return C["a0"] + C["a1"] * (mag - 6.0) + C["a2"] * (mag - 6.0) ** 2.


def _get_distance_scaling(C, mag, rhypo):
    """
    Returns the distance scalig term
    """
    return (C["a3"] * np.log(rhypo)) + (C["a4"] + C["a5"] * mag) * rhypo


[docs]class MegawatiPan2010(GMPE): """ Implements GMPE developed by Kusnowidjaja Megawati and Tso-Chien Pan and published as "Ground-motion attenuation relationship for the Sumatran megathrust earthquakes" (2010, Earthquake Engineering & Structural Dynamics Volume 39, Issue 8, pages 827-845). """ #: Supported tectonic region type is subduction interface along the #: Sumatra subduction zone. DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.SUBDUCTION_INTERFACE #: Supported intensity measure types are spectral acceleration, #: peak ground velocity and peak ground acceleration, see table IV #: pag. 837 DEFINED_FOR_INTENSITY_MEASURE_TYPES = {PGA, PGV, SA} #: Supported intensity measure component is geometric mean #: of two horizontal components, #: ####: PLEASE CONFIRM!!!!! 140709 DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.AVERAGE_HORIZONTAL #: Supported standard deviation types is total, see equation IV page 837. DEFINED_FOR_STANDARD_DEVIATION_TYPES = {const.StdDev.TOTAL} #: Required site parameter is only Vs30 (used to distinguish rock #: and deep soil). #: This GMPE is for very hard rock site condition, #: see the abstract page 827. REQUIRES_SITES_PARAMETERS = set() #: Required rupture parameters are magnitude, and focal depth, see #: equation 10 page 226. REQUIRES_RUPTURE_PARAMETERS = {'mag'} #: Required distance measure is hypocentral distance, #: see equation 1 page 834. REQUIRES_DISTANCES = {'rhypo'}
[docs] def compute(self, ctx, 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] = (_get_magnitude_scaling(C, ctx.mag) + _get_distance_scaling(C, ctx.mag, ctx.rhypo)) if imt.string.startswith(('PGA', 'SA')): mean[m] = np.log(np.exp(mean[m]) / (100.0 * g)) sig[m] = C['sigma']
#: Coefficient table for rock ctx, see table 3 page 227. COEFFS = CoeffsTable(sa_damping=5, table="""\ IMT a0 a1 a2 a3 a4 a5 sigma PGV 2.369 2.0852 -0.23564 -0.87906 -0.001363 0.0001189 0.3478 PGA 3.882 1.8988 -0.11736 -1.00000 -0.001741 0.0000776 0.2379 0.50 4.068 1.9257 -0.12435 -0.99864 -0.001790 0.0000564 0.2410 0.60 4.439 1.9094 -0.13693 -0.99474 -0.002462 0.0001051 0.2496 0.70 4.836 1.8308 -0.13510 -0.99950 -0.003323 0.0001945 0.2565 0.80 4.978 1.8570 -0.12887 -1.00000 -0.003054 0.0001475 0.2626 0.90 5.108 1.9314 -0.13954 -0.98621 -0.002986 0.0001075 0.2424 1.00 4.973 1.9547 -0.13913 -0.97603 -0.002851 0.0001106 0.2343 1.20 2.729 2.0316 -0.13658 -0.60751 -0.002570 0.0000409 0.2436 1.50 2.421 1.8960 -0.07075 -0.59262 -0.002453 0.0000668 0.2614 2.00 2.670 1.8182 -0.07657 -0.62089 -0.002190 0.0000674 0.2780 3.00 1.716 1.7922 -0.01895 -0.61167 -0.001177 0.0000121 0.2944 5.00 -0.060 1.8694 -0.09103 -0.32688 -0.001765 0.0000529 0.3963 7.00 0.518 2.1948 -0.24519 -0.47529 -0.001064 0.0000189 0.4206 10.00 0.044 2.3081 -0.29060 -0.50356 -0.000848 0.0000125 0.5183 15.00 -0.525 2.5297 -0.41930 -0.52777 -0.001454 0.0001435 0.4495 20.00 -1.695 2.5197 -0.42807 -0.42096 -0.001575 0.0001498 0.4543 30.00 -2.805 2.6640 -0.42674 -0.43304 -0.001576 0.0001568 0.3686 50.00 -4.340 2.2968 -0.27844 -0.38291 -0.002564 0.0002540 0.3946 """)