# Source code for openquake.hazardlib.gsim.gupta_2010

```
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2012-2017 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
:mod:`openquake.hazardlib.gsim.gupta_2010`
exports
:class:`Gupta2010SSlab`
"""
from openquake.hazardlib import const
from openquake.hazardlib.imt import PGA, SA
from openquake.hazardlib.gsim.base import CoeffsTable
from openquake.hazardlib.gsim.atkinson_boore_2003 \
import AtkinsonBoore2003SSlab
[docs]class Gupta2010SSlab(AtkinsonBoore2003SSlab):
# pylint: disable=too-few-public-methods
"""
Implements GMPE of Gupta (2010) for Indo-Burmese intraslab subduction.
This model is closely related to the model of Atkinson & Boore (2003).
In particular the functional form and coefficients ``C2``-``C7`` of
Gupta (2010) are adopted from Atkinson & Boore (2003). The only
substantive changes are a) the horizontal component modeled is different
(as noted below) b) a coefficient ``C8`` and a dummy variable ``v``
are added to model vertical motion and c) the coefficient ``C1`` is
recalculated based on a database of "a total of 56 three-component
accelerograms at 37 different sites from three in-slab earthquakes
along the Indo-Burmese subduction zone" (p 370).
Equation (2) p. 373 gives the form of the equation which was fitted:
``log Y - C2*M - C3*h - C4*R + g log R = C1 + C8*v + sigma``
The left-hand side of this equation was computed using event parameters
and the coefficients of Atkinson & Boore (2003). The regression
coefficients C1 and C8 on the right-hand side were slightly smoothed
after fitting. Note that since "v=0 for horizontal and 1 for vertical
motion", and since the current implementation only models horizontal
motion, we can subclass directly from
:class:`openquake.hazardlib.gsim.atkinson_boore_2003.AtkinsonBoore2003SSlab`,
modifying only the metadata constants and regression coefficients.
Page number citations in this documentation refer to Gupta (2010).
**References**
Gupta, I. (2010). Response spectral attenuation relations for in-slab
earthquakes in Indo-Burmese subduction zone. *Soil Dyn. Earthq. Eng.*,
30(5):368–377.
Atkinson, G. M. and Boore, D. M. (2003). Empirical ground-motion relations
for subduction-zone earthquakes and their application to Cascadia and other
regions. *Bull. Seism. Soc. Am.*, 93(4):1703–1729.
"""
#: As stated in the title.
DEFINED_FOR_TECTONIC_REGION_TYPE = const.TRT.SUBDUCTION_INTRASLAB
#: "The actual peak ground acceleration (PGA) from the corrected time
#: histories are taken as the response spectral amplitudes at a period of
#: 0.02 s (50 Hz frequency)." p. 371. Based on this comment, the
#: coefficients labeled as being for 0.02 s have been relabeld as PGA.
DEFINED_FOR_INTENSITY_MEASURE_TYPES = set([PGA, SA])
#: Unlike Atkinson & Boore (2003), "rather than the random horizontal
#: component, the geometric mean of both the horizontal components has
#: been used in the modified attenuation relations." (p. 376)
DEFINED_FOR_INTENSITY_MEASURE_COMPONENT = const.IMC.MEDIAN_HORIZONTAL
#: Since the database is small only the total standard deviation is
#: reported.
DEFINED_FOR_STANDARD_DEVIATION_TYPES = set([const.StdDev.TOTAL])
#: Coefficients taken from Table 3, p. 884. The row for 0.02 was
#: relabeled PGA since the paper indicates this is what it actually is
#: (see p. 371) and since these were the coefficients for PGA in
#: Atkinson & Boore (2003).
COEFFS_SSLAB = CoeffsTable(sa_damping=5., table="""\
IMT c1 c2 c3 c4 c5 c6 c7 c8 sigma
pga 0.4598 0.69090 0.01130 -0.00202 0.19 0.24 0.29 -0.3312 0.347
0.04 0.7382 0.63273 0.01275 -0.00234 0.15 0.20 0.20 -0.3090 0.343
0.10 1.0081 0.66675 0.01080 -0.00219 0.15 0.23 0.20 -0.3005 0.341
0.20 1.2227 0.69186 0.00572 -0.00192 0.15 0.27 0.25 -0.4001 0.340
0.40 0.8798 0.77270 0.00173 -0.00178 0.13 0.37 0.38 -0.4408 0.341
1.00 -0.3339 0.87890 0.00130 -0.00173 0.10 0.30 0.55 -0.3380 0.344
2.00 -2.0677 0.99640 0.00364 -0.00118 0.10 0.25 0.40 -0.2674 0.347
3.00 -3.4227 1.11690 0.00615 -0.00045 0.10 0.25 0.36 -0.3942 0.351
""")
#: Mean value data obtained from author matched well at 1 s and below but
#: not at longer periods. As a temporary measure the reference test result
#: has been generated from the current implementation.
non_verified = True
```