Source code for openquake.hazardlib.gsim.ambraseys_1996
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2014-2023 GEM Foundation
#
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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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# GNU Affero General Public License for more details.
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# You should have received a copy of the GNU Affero General Public License
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"""
Module exports :class:`AmbraseysEtAl1996`.
"""
import numpy as np
from openquake.hazardlib.gsim.base import GMPE, CoeffsTable
from openquake.hazardlib.gsim import utils
from openquake.hazardlib import const
from openquake.hazardlib.imt import PGA, SA
def _compute_magnitude(ctx, C):
"""
Added a function that converts the input magnitudes Mw into Ms.
Function from Appendix 1 (pag. 9) of "Gruppo di Lavoro (2004).
Redazione della mappa di pericolosità sismica prevista dall’Ordinanza
PCM 3274 del 20 marzo 2003. Rapporto Conclusivo per il Dipartimento
della Protezione Civile, INGV, Milano-Roma"
"""
Ms = (ctx.mag - 1.938)/0.673
return C['c1'] + (C['c2'] * Ms)
def _compute_distance(ctx, C):
#convertion from repi to rjb if M>6 (Montaldo et al 2005, eq. 3)
R = np.where(ctx.mag >= 6, -3.5525 + (0.8845 * ctx.repi), ctx.repi)
R = np.where(R < 0, 0, R)
return (C['c4']* np.log10(np.sqrt(R ** 2 + C['h'] ** 2)))
def _site_amplification(ctx, C):
#site condition
ssa = np.zeros(len(ctx.vs30))
sss = np.zeros(len(ctx.vs30))
idx = (ctx.vs30 > 360.0) & (ctx.vs30 <= 750.0)
ssa[idx] = 1.0
idx = (ctx.vs30 <= 360.0)
sss[idx] = 1.0
return C['ca'] * ssa + C['cs'] * sss
def _get_mechanism(ctx, C):
#style of faulting correction as in Montale et al 2005 (Table 2)
SS, NS, RS = utils.get_fault_type_dummy_variables(ctx)
idx = (ctx.mag < 6)
SS[idx] = 0
NS[idx] = 0
RS[idx] = 0
Fr = np.log10(1.13)
Fn = np.log10(0.88)
Fss = np.log10(0.93)
return Fr*RS + Fn*NS + Fss*SS
[docs]class AmbraseysEtAl1996(GMPE):
"""
Implements GMPE developed by Ambraseys, N. N., Simpson, K. U., &
Bommer, J. J. (1996). Prediction of horizontal response spectra in Europe.
Earthquake Engineering & Structural Dynamics, 25(4), 371-400.
SA are given up to 2 s.
The regressions are developed considering the largest horizontal component
GMPE implemented as adopted in MPS04 (Montaldo et al 2005).
In this implementation, a convertion function from Mw to Ms is included
to be consistent with the other gsims in OQ.
"""
#: Supported tectonic region type is 'active shallow crust'
DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.ACTIVE_SHALLOW_CRUST
#: Set of :mod:`intensity measure types <openquake.hazardlib.imt>`
#: this GSIM can calculate. A set should contain classes from module
#: :mod:`openquake.hazardlib.imt`.
DEFINED_FOR_INTENSITY_MEASURE_TYPES = {PGA, SA}
#: Supported intensity measure component is the largest
#: horizontal component
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.GREATER_OF_TWO_HORIZONTAL
#: Supported standard deviation type is total
DEFINED_FOR_STANDARD_DEVIATION_TYPES = {const.StdDev.TOTAL}
#: Required site parameter is only Vs30
REQUIRES_SITES_PARAMETERS = {'vs30'}
#: Required rupture parameters are magnitude and rake.
REQUIRES_RUPTURE_PARAMETERS = {'mag', 'rake'}
#: Required distance measure is Repi
REQUIRES_DISTANCES = {'repi'}
[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]
imean = _compute_magnitude(ctx, C) + \
_compute_distance(ctx, C) + \
_site_amplification(ctx, C) +\
_get_mechanism(ctx, C)
# convert from base 10 to base e (already in g)
mean[m] = np.log(10.0 ** imean)
# Return stddevs in terms of natural log scaling
sig[m] = np.log(10.0 ** C['sigma'])
#: Coefficients for PGA and SA
COEFFS = CoeffsTable(sa_damping=5, table="""
IMT c1 c2 h c4 ca cs sigma
pga -1.48 0.266 3.5 -0.922 0.117 0.124 0.25
0.10 -0.84 0.219 4.5 -0.954 0.078 0.027 0.27
0.11 -0.86 0.221 4.5 -0.945 0.098 0.036 0.27
0.12 -0.87 0.231 4.7 -0.960 0.111 0.052 0.27
0.13 -0.87 0.238 5.3 -0.981 0.131 0.068 0.27
0.14 -0.94 0.244 4.9 -0.955 0.136 0.077 0.27
0.15 -0.98 0.247 4.7 -0.938 0.143 0.085 0.27
0.16 -1.05 0.252 4.4 -0.907 0.152 0.101 0.27
0.17 -1.08 0.258 4.3 -0.896 0.140 0.102 0.27
0.18 -1.13 0.268 4.0 -0.901 0.129 0.107 0.27
0.19 -1.19 0.278 3.9 -0.907 0.133 0.130 0.28
0.20 -1.21 0.284 4.2 -0.922 0.135 0.142 0.27
0.22 -1.28 0.295 4.1 -0.911 0.120 0.143 0.28
0.24 -1.37 0.308 3.9 -0.916 0.124 0.155 0.28
0.26 -1.40 0.318 4.3 -0.942 0.134 0.163 0.28
0.28 -1.46 0.326 4.4 -0.946 0.134 0.158 0.29
0.30 -1.55 0.338 4.2 -0.933 0.133 0.148 0.30
0.32 -1.63 0.349 4.2 -0.932 0.125 0.161 0.31
0.34 -1.65 0.351 4.4 -0.939 0.118 0.163 0.31
0.36 -1.69 0.354 4.5 -0.936 0.124 0.160 0.31
0.38 -1.82 0.364 3.9 -0.900 0.132 0.164 0.31
0.40 -1.94 0.377 3.6 -0.888 0.139 0.172 0.31
0.42 -1.99 0.384 3.7 -0.897 0.147 0.180 0.32
0.44 -2.05 0.393 3.9 -0.908 0.153 0.187 0.32
0.46 -2.11 0.401 3.7 -0.911 0.149 0.191 0.32
0.48 -2.17 0.410 3.5 -0.920 0.150 0.197 0.32
0.50 -2.25 0.420 3.3 -0.913 0.147 0.201 0.32
0.55 -2.38 0.434 3.1 -0.911 0.134 0.203 0.32
0.60 -2.49 0.438 2.5 -0.881 0.124 0.212 0.32
0.65 -2.58 0.451 2.8 -0.901 0.122 0.215 0.32
0.70 -2.67 0.463 3.1 -0.914 0.116 0.214 0.33
0.75 -2.75 0.477 3.5 -0.942 0.113 0.212 0.32
0.80 -2.86 0.485 3.7 -0.925 0.127 0.218 0.32
0.85 -2.93 0.492 3.9 -0.920 0.124 0.218 0.32
0.90 -3.03 0.502 4.0 -0.920 0.124 0.225 0.32
0.95 -3.10 0.503 4.0 -0.892 0.121 0.217 0.32
1.00 -3.17 0.508 4.3 -0.885 0.128 0.219 0.32
1.10 -3.30 0.513 4.0 -0.857 0.123 0.206 0.32
1.20 -3.38 0.513 3.6 -0.851 0.128 0.214 0.31
1.30 -3.43 0.514 3.6 -0.848 0.115 0.200 0.31
1.40 -3.52 0.522 3.4 -0.839 0.109 0.197 0.31
1.50 -3.61 0.524 3.0 -0.817 0.109 0.204 0.31
1.60 -3.68 0.520 2.5 -0.781 0.108 0.206 0.31
1.70 -3.74 0.517 2.5 -0.759 0.105 0.206 0.31
1.80 -3.79 0.514 2.4 -0.730 0.104 0.204 0.32
1.90 -3.80 0.508 2.8 -0.724 0.103 0.194 0.32
2.00 -3.79 0.503 3.2 -0.728 0.101 0.182 0.32
""")
