# The Hazard Library
# Copyright (C) 2012-2025 GEM Foundation
#
# This program 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.
#
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
"""
Module :mod:`openquake.hazardlib.mgmp.nrcan15_site_term` implements
:class:`~openquake.hazardlib.mgmpe.NRCan15SiteTerm`
"""
import copy
import numpy as np
from openquake.hazardlib import const
from openquake.hazardlib.gsim.base import CoeffsTable
from openquake.hazardlib.gsim.base import GMPE, registry
from openquake.hazardlib.gsim.atkinson_boore_2006 import (
_get_site_amplification_non_linear, _get_site_amplification_linear)
from openquake.baselib.general import CallableDict
BA08_AB06 = CallableDict()
[docs]@BA08_AB06.add("base")
def BA08_AB06_base(kind, C, C2, vs30, imt, pgar):
"""
Computes amplification factor similarly to what is done in the 2015
version of the Canada building code. An initial version of this code
was kindly provided by Michal Kolaj - Geological Survey of Canada
:param vs30:
Can be either a scalar or a :class:`~numpy.ndarray` instance
:param imt:
The intensity measure type
:param pgar:
The value of hazard on rock (vs30=760). Can be either a scalar or
a :class:`~numpy.ndarray` instance. Unit of measure is fractions
of gravity acceleration.
:return:
A scalar or a :class:`~numpy.ndarray` instance with the
amplification factor.
"""
fa = np.ones_like(vs30)
if np.isscalar(vs30):
vs30 = np.array([vs30])
if np.isscalar(pgar):
pgar = np.array([pgar])
#
# Fixing vs30 for hard rock to 1999 m/s. Beyond this threshold the
# motion will not be deamplified further
vs = copy.copy(vs30)
vs[vs >= 2000] = 1999.
#
# Computing motion on rock
idx = np.where(vs30 > 760)
if np.size(idx) > 0:
"""
# This is the original implementation - Since this code is
# experimental we keep it for possible further developments
# For values of Vs30 greater than 760 a linear interpolation is
# used between the gm factor at 2000 m/s and 760 m/s
fa[idx] = 10**(np.interp(np.log10(vs[idx]),
np.log10([760.0, 2000.0]),
np.log10([1.0, C2['c']])))
"""
nl = _get_site_amplification_non_linear(vs[idx], pgar[idx], C)
lin = _get_site_amplification_linear(vs[idx], C)
tmp = np.exp(nl+lin)
fa[idx] = tmp
#
# For values of Vs30 lower than 760 the amplification is computed
# using the site term of Boore and Atkinson (2008)
idx = np.where(vs < 760.)
if np.size(idx) > 0:
nl = _get_site_amplification_non_linear(vs[idx], pgar[idx], C)
lin = _get_site_amplification_linear(vs[idx], C)
fa[idx] = np.exp(nl+lin)
return fa
[docs]@BA08_AB06.add("linear")
def BA08_AB06_linear(kind, C, C2, vs30, imt, pgar):
"""
Computes amplification factor using an approach similar to the one used
for the 2015 Canada Buiding code. Michal Kolaj's help is acknoledged.
:param vs30:
an be either a scalar or a :class:`~numpy.ndarray` instance
:param imt:
The intensity measure type
:param pgar:
The value of hazard on rock (vs30=760). Can be either a scalar or
a :class:`~numpy.ndarray` instance. Unit of measure is fractions
of gravity acceleration.
:return:
A scalar or a :class:`~numpy.ndarray` instance with the
amplification factor.
"""
fa = np.ones_like(vs30)
if np.isscalar(vs30):
vs30 = np.array([vs30])
if np.isscalar(pgar):
pgar = np.array([pgar])
#
# Fixing vs30 for hard rock to 1999 m/s. Beyond this threshold the
# motion will not be modified
vs = copy.copy(vs30)
vs[vs >= 2000] = 2000.
#
# Computing motion on rock
idx = np.where(vs30 > 760)
if np.size(idx) > 0:
fa[idx] = 1. / 10**(np.interp(np.log10(vs[idx]),
np.log10([760.0, 2000.0]),
np.log10([1.0, C2['c']])))
#
# For values of Vs30 lower than 760 the amplification is computed
# using the site term of Boore and Atkinson (2008)
idx = np.where(vs < 760.)
if np.size(idx) > 0:
nl = _get_site_amplification_non_linear(vs[idx], pgar[idx], C)
lin = _get_site_amplification_linear(vs[idx], C)
fa[idx] = np.exp(nl+lin)
return fa
[docs]class NRCan15SiteTerm(GMPE):
"""
Implements a modified GMPE class that can be used to account for local
soil conditions in the estimation of ground motion.
:param gmpe_name:
The name of a GMPE class
"""
kind = "base"
# Parameters
REQUIRES_SITES_PARAMETERS = {'vs30'}
#: Required distances are set on the underlying gmpe
REQUIRES_DISTANCES = set()
REQUIRES_RUPTURE_PARAMETERS = set()
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = ''
DEFINED_FOR_INTENSITY_MEASURE_TYPES = set()
DEFINED_FOR_STANDARD_DEVIATION_TYPES = {const.StdDev.TOTAL}
DEFINED_FOR_TECTONIC_REGION_TYPE = ''
DEFINED_FOR_REFERENCE_VELOCITY = None
def __init__(self, gmpe_name, **kwargs):
self.gmpe = registry[gmpe_name](**kwargs)
self.set_parameters()
# Check if this GMPE has the necessary requirements
if not (hasattr(self.gmpe, 'DEFINED_FOR_REFERENCE_VELOCITY') or
'vs30' in self.gmpe.REQUIRES_SITES_PARAMETERS):
msg = '{:s} does not use vs30 nor a defined reference velocity'
raise AttributeError(msg.format(str(self.gmpe)))
if 'vs30' not in self.gmpe.REQUIRES_SITES_PARAMETERS:
self.REQUIRES_SITES_PARAMETERS = frozenset(
self.gmpe.REQUIRES_SITES_PARAMETERS | {'vs30'})
# Check compatibility of reference velocity
if hasattr(self.gmpe, 'DEFINED_FOR_REFERENCE_VELOCITY'):
ok = 760 <= self.gmpe.DEFINED_FOR_REFERENCE_VELOCITY <= 820
if not ok:
name = self.gmpe.__class__.__name__
raise ValueError(f'{name}.DEFINED_FOR_REFERENCE_VELOCITY '
'is not in the range 760..800')
[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.
"""
# compute mean and standard deviations on rock
ctx_rock = copy.copy(ctx)
ctx_rock.vs30 = np.full_like(ctx.vs30, 760.)
self.gmpe.compute(ctx_rock, imts, mean, sig, tau, phi)
for m, imt in enumerate(imts):
C = self.COEFFS_BA08[imt]
C2 = self.COEFFS_AB06r[imt]
fa = BA08_AB06(self.kind, C, C2, ctx.vs30, imt, np.exp(mean[m]))
mean[m] = np.log(np.exp(mean[m]) * fa)
COEFFS_AB06r = CoeffsTable(sa_damping=5, table="""\
IMT c
pgv 1.230
pga 0.891
0.05 0.891
0.10 1.072
0.20 1.318
0.30 1.380
0.50 1.380
1.00 1.288
2.00 1.230
5.00 1.148
10.0 1.072
""")
COEFFS_BA08 = CoeffsTable(sa_damping=5, table="""\
IMT blin b1 b2
pgv -0.60 -0.50 -0.06
pga -0.36 -0.64 -0.14
0.010 -0.36 -0.64 -0.14
0.020 -0.34 -0.63 -0.12
0.030 -0.33 -0.62 -0.11
0.040 -0.31 -0.61 -0.11
0.050 -0.29 -0.64 -0.11
0.060 -0.25 -0.64 -0.11
0.075 -0.23 -0.64 -0.11
0.090 -0.23 -0.64 -0.12
0.100 -0.25 -0.60 -0.13
0.120 -0.26 -0.56 -0.14
0.150 -0.28 -0.53 -0.18
0.170 -0.29 -0.53 -0.19
0.200 -0.31 -0.52 -0.19
0.240 -0.38 -0.52 -0.16
0.250 -0.39 -0.52 -0.16
0.300 -0.44 -0.52 -0.14
0.360 -0.48 -0.51 -0.11
0.400 -0.50 -0.51 -0.10
0.460 -0.55 -0.50 -0.08
0.500 -0.60 -0.50 -0.06
0.600 -0.66 -0.49 -0.03
0.750 -0.69 -0.47 -0.00
0.850 -0.69 -0.46 -0.00
1.000 -0.70 -0.44 -0.00
1.500 -0.72 -0.40 -0.00
2.000 -0.73 -0.38 -0.00
3.000 -0.74 -0.34 -0.00
4.000 -0.75 -0.31 -0.00
5.000 -0.75 -0.291 -0.00
7.500 -0.692 -0.247 -0.00
10.00 -0.650 -0.215 -0.00
""")
[docs]class NRCan15SiteTermLinear(NRCan15SiteTerm):
"""
Implements a modified GMPE class that can be used to account for local
soil conditions in the estimation of ground motion.
This site term issimilar in structure to the
:class:`openquake.hazardlib.gsim.mgmpe.NRCan15SiteTerm` in the OQengine
but uses a different scaling of the motion for values of Vs30 greater
than 760 m/s.
This implementation follows what suggested in
http://www.daveboore.com/pubs_online/ab06_gmpes_programs_and_tables.pdf.
:param gmpe_name:
The name of a GMPE class
"""
kind = "linear"
COEFFS_AB06r = CoeffsTable(sa_damping=5, table="""\
IMT c
pgv 1.230
pga 0.891
0.05 0.891
0.10 1.072
0.20 1.318
0.30 1.380
0.50 1.380
1.00 1.288
2.00 1.230
5.00 1.148
10.0 1.072
""")
COEFFS_BA08 = CoeffsTable(sa_damping=5, table="""\
IMT blin b1 b2
pgv -0.60 -0.50 -0.06
pga -0.36 -0.64 -0.14
0.010 -0.36 -0.64 -0.14
0.020 -0.34 -0.63 -0.12
0.030 -0.33 -0.62 -0.11
0.040 -0.31 -0.61 -0.11
0.050 -0.29 -0.64 -0.11
0.060 -0.25 -0.64 -0.11
0.075 -0.23 -0.64 -0.11
0.090 -0.23 -0.64 -0.12
0.100 -0.25 -0.60 -0.13
0.120 -0.26 -0.56 -0.14
0.150 -0.28 -0.53 -0.18
0.170 -0.29 -0.53 -0.19
0.200 -0.31 -0.52 -0.19
0.240 -0.38 -0.52 -0.16
0.250 -0.39 -0.52 -0.16
0.300 -0.44 -0.52 -0.14
0.360 -0.48 -0.51 -0.11
0.400 -0.50 -0.51 -0.10
0.460 -0.55 -0.50 -0.08
0.500 -0.60 -0.50 -0.06
0.600 -0.66 -0.49 -0.03
0.750 -0.69 -0.47 -0.00
0.850 -0.69 -0.46 -0.00
1.000 -0.70 -0.44 -0.00
1.500 -0.72 -0.40 -0.00
2.000 -0.73 -0.38 -0.00
3.000 -0.74 -0.34 -0.00
4.000 -0.75 -0.31 -0.00
5.000 -0.75 -0.291 -0.00
7.500 -0.692 -0.247 -0.00
10.00 -0.650 -0.215 -0.00
""")
