# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2012-2021 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:`ChiouYoungs2008`.
"""
import numpy as np
from openquake.hazardlib.gsim.base import GMPE, CoeffsTable
from openquake.hazardlib import const
from openquake.hazardlib.imt import PGA, PGV, SA
[docs]class ChiouYoungs2008(GMPE):
"""
Implements GMPE developed by Brian S.-J. Chiou and Robert R. Youngs
and published as "An NGA Model for the Average Horizontal Component
of Peak Ground Motion and Response Spectra" (2008, Earthquake Spectra,
Volume 24, No. 1, pages 173-215).
"""
#: Supported tectonic region type is active shallow crust, see page 174.
DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.ACTIVE_SHALLOW_CRUST
#: Supported intensity measure types are spectral acceleration,
#: peak ground velocity and peak ground acceleration, see tables
#: at pages 198 and 199.
DEFINED_FOR_INTENSITY_MEASURE_TYPES = set([
PGA,
PGV,
SA
])
#: Supported intensity measure component is orientation-independent
#: measure :attr:`~openquake.hazardlib.const.IMC.GMRotI50`, see page 174.
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.GMRotI50
#: Supported standard deviation types are inter-event, intra-event
#: and total, see chapter "Variance model".
DEFINED_FOR_STANDARD_DEVIATION_TYPES = set([
const.StdDev.TOTAL,
const.StdDev.INTER_EVENT,
const.StdDev.INTRA_EVENT
])
DEFINED_FOR_REFERENCE_VELOCITY = 1130.
#: Required site parameters are Vs30 (eq. 13b), Vs30 measured flag (eq. 20)
#: and Z1.0 (eq. 13b).
REQUIRES_SITES_PARAMETERS = {'vs30', 'vs30measured', 'z1pt0'}
#: Required rupture parameters are magnitude, rake (eq. 13a and 13b),
#: dip (eq. 13a) and ztor (eq. 13a).
REQUIRES_RUPTURE_PARAMETERS = {'dip', 'rake', 'mag', 'ztor'}
#: Required distance measures are RRup, Rjb and Rx (all are in eq. 13a).
REQUIRES_DISTANCES = {'rrup', 'rjb', 'rx'}
[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.
"""
# extracting dictionary of coefficients specific to required
# intensity measure type.
C = self.COEFFS[imt]
# intensity on a reference soil is used for both mean
# and stddev calculations.
ln_y_ref = self._get_ln_y_ref(rup, dists, C)
# exp1 and exp2 are parts of eq. 10 and eq. 13b,
# calculate it once for both.
exp1 = np.exp(C['phi3'] * (sites.vs30.clip(-np.inf, 1130) - 360))
exp2 = np.exp(C['phi3'] * (1130 - 360))
mean = self._get_mean(sites, C, ln_y_ref, exp1, exp2)
stddevs = self._get_stddevs(sites, rup, C, stddev_types,
ln_y_ref, exp1, exp2)
return mean, stddevs
def _get_mean(self, sites, C, ln_y_ref, exp1, exp2):
"""
Add site effects to an intensity.
Implements eq. 13b.
"""
# we do not support estimating of basin depth and instead
# rely on it being available (since we require it).
z1pt0 = sites.z1pt0
# we consider random variables being zero since we want
# to find the exact mean value.
eta = epsilon = 0
ln_y = (
# first line of eq. 13b
ln_y_ref + C['phi1'] * np.log(sites.vs30 / 1130).clip(-np.inf, 0)
# second line
+ C['phi2'] * (exp1 - exp2)
* np.log((np.exp(ln_y_ref) + C['phi4']) / C['phi4'])
# third line
+ C['phi5']
* (1.0 - 1.0 / np.cosh(
C['phi6'] * (z1pt0 - C['phi7']).clip(0, np.inf)))
+ C['phi8'] / np.cosh(0.15 * (z1pt0 - 15).clip(0, np.inf))
# fourth line
+ eta + epsilon
)
return ln_y
def _get_stddevs(self, sites, rup, C, stddev_types, ln_y_ref, exp1, exp2):
"""
Get standard deviation for a given intensity on reference soil.
Implements equations 19, 20 and 21 for inter-event, intra-event
and total standard deviations respectively.
"""
# aftershock flag is zero, we consider only main shock.
AS = 0
Fmeasured = sites.vs30measured
Finferred = 1 - sites.vs30measured
# eq. 19 to calculate inter-event standard error
mag_test = min(max(rup.mag, 5.0), 7.0) - 5.0
tau = C['tau1'] + (C['tau2'] - C['tau1']) / 2 * mag_test
# b and c coeffs from eq. 10
b = C['phi2'] * (exp1 - exp2)
c = C['phi4']
y_ref = np.exp(ln_y_ref)
# eq. 20
NL = b * y_ref / (y_ref + c)
sigma = (
# first line of eq. 20
(C['sig1']
+ 0.5 * (C['sig2'] - C['sig1']) * mag_test
+ C['sig4'] * AS)
# second line
* np.sqrt((C['sig3'] * Finferred + 0.7 * Fmeasured)
+ (1 + NL) ** 2)
)
ret = []
for stddev_type in stddev_types:
assert stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
if stddev_type == const.StdDev.TOTAL:
# eq. 21
ret += [np.sqrt(((1 + NL) ** 2) * (tau ** 2) + (sigma ** 2))]
elif stddev_type == const.StdDev.INTRA_EVENT:
ret.append(sigma)
elif stddev_type == const.StdDev.INTER_EVENT:
# this is implied in eq. 21
ret.append(np.abs((1 + NL) * tau))
return ret
def _get_ln_y_ref(self, rup, dists, C):
"""
Get an intensity on a reference soil.
Implements eq. 13a.
"""
# reverse faulting flag
Frv = 1 if 30 <= rup.rake <= 150 else 0
# normal faulting flag
Fnm = 1 if -120 <= rup.rake <= -60 else 0
# hanging wall flag
Fhw = (dists.rx >= 0)
# aftershock flag. always zero since we only consider main shock
AS = 0
ln_y_ref = (
# first line of eq. 13a
C['c1']
+ (C['c1a'] * Frv
+ C['c1b'] * Fnm
+ C['c7'] * (rup.ztor - 4))
* (1 - AS)
+ (C['c10'] + C['c7a'] * (rup.ztor - 4)) * AS
# second line
+ C['c2'] * (rup.mag - 6)
+ ((C['c2'] - C['c3']) / C['cn'])
* np.log(1 + np.exp(C['cn'] * (C['cm'] - rup.mag)))
# third line
+ C['c4']
* np.log(dists.rrup
+ C['c5']
* np.cosh(C['c6'] * max(rup.mag - C['chm'], 0)))
# fourth line
+ (C['c4a'] - C['c4'])
* np.log(np.sqrt(dists.rrup ** 2 + C['crb'] ** 2))
# fifth line
+ (C['cg1'] + C['cg2'] / (np.cosh(max(rup.mag - C['cg3'], 0))))
* dists.rrup
# sixth line
+ C['c9'] * Fhw
* np.tanh(dists.rx
* (np.cos(np.radians(rup.dip)) ** 2)
/ C['c9a'])
* (1 - np.sqrt(dists.rjb ** 2 + rup.ztor ** 2)
/ (dists.rrup + 0.001))
)
return ln_y_ref
#: Coefficient tables are constructed from values in tables 1, 2 and 3
#: (pages 197, 198 and 199). Spectral acceleration is defined for damping
#: of 5%, see page 208.
COEFFS = CoeffsTable(sa_damping=5, table="""\
IMT c2 c3 c4 c4a crb chm cg3 c1 c1a c1b cn cm c5 c6 c7 c7a c9 c9a c10 cg1 cg2 phi1 phi2 phi3 phi4 phi5 phi6 phi7 phi8 tau1 tau2 sig1 sig2 sig3 sig4
pga 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.2687 0.1000 -0.2550 2.996 4.1840 6.1600 0.4893 0.0512 0.0860 0.7900 1.5005 -0.3218 -0.00804 -0.00785 -0.4417 -0.1417 -0.007010 0.102151 0.2289 0.014996 580.0 0.0700 0.3437 0.2637 0.4458 0.3459 0.8000 0.0663
pgv 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 2.2884 0.1094 -0.0626 1.648 4.2979 5.1700 0.4407 0.0207 0.0437 0.3079 2.6690 -0.1166 -0.00275 -0.00625 -0.7861 -0.0699 -0.008444 5.410000 0.2899 0.006718 459.0 0.1138 0.2539 0.2381 0.4496 0.3554 0.7504 0.0133
0.010 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.2687 0.1000 -0.2550 2.996 4.1840 6.1600 0.4893 0.0512 0.0860 0.7900 1.5005 -0.3218 -0.00804 -0.00785 -0.4417 -0.1417 -0.007010 0.102151 0.2289 0.014996 580.0 0.0700 0.3437 0.2637 0.4458 0.3459 0.8000 0.0663
0.020 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.2515 0.1000 -0.2550 3.292 4.1879 6.1580 0.4892 0.0512 0.0860 0.8129 1.5028 -0.3323 -0.00811 -0.00792 -0.4340 -0.1364 -0.007279 0.108360 0.2289 0.014996 580.0 0.0699 0.3471 0.2671 0.4458 0.3459 0.8000 0.0663
0.030 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.1744 0.1000 -0.2550 3.514 4.1556 6.1550 0.4890 0.0511 0.0860 0.8439 1.5071 -0.3394 -0.00839 -0.00819 -0.4177 -0.1403 -0.007354 0.119888 0.2289 0.014996 580.0 0.0701 0.3603 0.2803 0.4535 0.3537 0.8000 0.0663
0.040 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.0671 0.1000 -0.2550 3.563 4.1226 6.1508 0.4888 0.0508 0.0860 0.8740 1.5138 -0.3453 -0.00875 -0.00855 -0.4000 -0.1591 -0.006977 0.133641 0.2289 0.014996 579.9 0.0702 0.3718 0.2918 0.4589 0.3592 0.8000 0.0663
0.050 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.9464 0.1000 -0.2550 3.547 4.1011 6.1441 0.4884 0.0504 0.0860 0.8996 1.5230 -0.3502 -0.00912 -0.00891 -0.3903 -0.1862 -0.006467 0.148927 0.2290 0.014996 579.9 0.0701 0.3848 0.3048 0.4630 0.3635 0.8000 0.0663
0.075 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.7051 0.1000 -0.2540 3.448 4.0860 6.1200 0.4872 0.0495 0.0860 0.9442 1.5597 -0.3579 -0.00973 -0.00950 -0.4040 -0.2538 -0.005734 0.190596 0.2292 0.014996 579.6 0.0686 0.3878 0.3129 0.4702 0.3713 0.8000 0.0663
0.10 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.5747 0.1000 -0.2530 3.312 4.1030 6.0850 0.4854 0.0489 0.0860 0.9677 1.6104 -0.3604 -0.00975 -0.00952 -0.4423 -0.2943 -0.005604 0.230662 0.2297 0.014996 579.2 0.0646 0.3835 0.3152 0.4747 0.3769 0.8000 0.0663
0.15 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.5309 0.1000 -0.2500 3.044 4.1717 5.9871 0.4808 0.0479 0.0860 0.9660 1.7549 -0.3565 -0.00883 -0.00862 -0.5162 -0.3113 -0.005845 0.266468 0.2326 0.014988 577.2 0.0494 0.3719 0.3128 0.4798 0.3847 0.8000 0.0612
0.20 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.6352 0.1000 -0.2449 2.831 4.2476 5.8699 0.4755 0.0471 0.0860 0.9334 1.9157 -0.3470 -0.00778 -0.00759 -0.5697 -0.2927 -0.006141 0.255253 0.2386 0.014964 573.9 -0.0019 0.3601 0.3076 0.4816 0.3902 0.8000 0.0530
0.25 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.7766 0.1000 -0.2382 2.658 4.3184 5.7547 0.4706 0.0464 0.0860 0.8946 2.0709 -0.3379 -0.00688 -0.00671 -0.6109 -0.2662 -0.006439 0.231541 0.2497 0.014881 568.5 -0.0479 0.3522 0.3047 0.4815 0.3946 0.7999 0.0457
0.30 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -0.9278 0.0999 -0.2313 2.505 4.3844 5.6527 0.4665 0.0458 0.0860 0.8590 2.2005 -0.3314 -0.00612 -0.00598 -0.6444 -0.2405 -0.006704 0.207277 0.2674 0.014639 560.5 -0.0756 0.3438 0.3005 0.4801 0.3981 0.7997 0.0398
0.40 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.2176 0.0997 -0.2146 2.261 4.4979 5.4997 0.4607 0.0445 0.0850 0.8019 2.3886 -0.3256 -0.00498 -0.00486 -0.6931 -0.1975 -0.007125 0.165464 0.3120 0.013493 540.0 -0.0960 0.3351 0.2984 0.4758 0.4036 0.7988 0.0312
0.50 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.4695 0.0991 -0.1972 2.087 4.5881 5.4029 0.4571 0.0429 0.0830 0.7578 2.5000 -0.3189 -0.00420 -0.00410 -0.7246 -0.1633 -0.007435 0.133828 0.3610 0.011133 512.9 -0.0998 0.3353 0.3036 0.4710 0.4079 0.7966 0.0255
0.75 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -1.9278 0.0936 -0.1620 1.812 4.7571 5.2900 0.4531 0.0387 0.0690 0.6788 2.6224 -0.2702 -0.00308 -0.00301 -0.7708 -0.1028 -0.008120 0.085153 0.4353 0.006739 441.9 -0.0765 0.3429 0.3205 0.4621 0.4157 0.7792 0.0175
1.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -2.2453 0.0766 -0.1400 1.648 4.8820 5.2480 0.4517 0.0350 0.0450 0.6196 2.6690 -0.2059 -0.00246 -0.00241 -0.7990 -0.0699 -0.008444 0.058595 0.4629 0.005749 391.8 -0.0412 0.3577 0.3419 0.4581 0.4213 0.7504 0.0133
1.5 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -2.7307 0.0022 -0.1184 1.511 5.0697 5.2194 0.4507 0.0280 0.0134 0.5101 2.6985 -0.0852 -0.00180 -0.00176 -0.8382 -0.0425 -0.007707 0.031787 0.4756 0.005544 348.1 0.0140 0.3769 0.3703 0.4493 0.4213 0.7136 0.0090
2.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -3.1413 -0.0591 -0.1100 1.470 5.2173 5.2099 0.4504 0.0213 0.0040 0.3917 2.7085 0.0160 -0.00147 -0.00143 -0.8663 -0.0302 -0.004792 0.019716 0.4785 0.005521 332.5 0.0544 0.4023 0.4023 0.4459 0.4213 0.7035 0.0068
3.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -3.7413 -0.0931 -0.1040 1.456 5.4385 5.2040 0.4501 0.0106 0.0010 0.1244 2.7145 0.1876 -0.00117 -0.00115 -0.9032 -0.0129 -0.001828 0.009643 0.4796 0.005517 324.1 0.1232 0.4406 0.4406 0.4433 0.4213 0.7006 0.0045
4.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -4.1814 -0.0982 -0.1020 1.465 5.5977 5.2020 0.4501 0.0041 0.0000 0.0086 2.7164 0.3378 -0.00107 -0.00104 -0.9231 -0.0016 -0.001523 0.005379 0.4799 0.005517 321.7 0.1859 0.4784 0.4784 0.4424 0.4213 0.7001 0.0034
5.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -4.5187 -0.0994 -0.1010 1.478 5.7276 5.2010 0.4500 0.0010 0.0000 0.0000 2.7172 0.4579 -0.00102 -0.00099 -0.9222 0.0000 -0.001440 0.003223 0.4799 0.005517 320.9 0.2295 0.5074 0.5074 0.4420 0.4213 0.7000 0.0027
7.5 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -5.1224 -0.0999 -0.1010 1.498 5.9891 5.2000 0.4500 0.0000 0.0000 0.0000 2.7177 0.7514 -0.00096 -0.00094 -0.8346 0.0000 -0.001369 0.001134 0.4800 0.005517 320.3 0.2660 0.5328 0.5328 0.4416 0.4213 0.7000 0.0018
10.0 1.06 3.45 -2.1 -0.5 50.0 3.0 4.0 -5.5872 -0.1000 -0.1000 1.502 6.1930 5.2000 0.4500 0.0000 0.0000 0.0000 2.7180 1.1856 -0.00094 -0.00091 -0.7332 0.0000 -0.001361 0.000515 0.4800 0.005517 320.1 0.2682 0.5542 0.5542 0.4414 0.4213 0.7000 0.0014
""")