3.5. User-Defined Average Spectral Acceleration

imcalculator.get_saavg_user_defined(periods_list)

Computes the geometric mean of spectral accelerations for a user-defined list of periods.

Parameters:

periods_list (list or numpy.ndarray) – List of user-defined periods (s) at which spectral accelerations are computed.

Returns:

psa_avg – Geometric mean of pseudo-spectral accelerations (g) over the user-defined periods.

Return type:

float

References

Cordova, P., Deierlein, G., Mehanny, S., and Cornell, A., 2000.

Development of a two-parameter seismic intensity measure and probabilistic assessment procedure. 2nd US–Japan Workshop on Performance-Based Earthquake Engineering Methodology for RC Building Structures.

Eads, L., Miranda, E., and Lignos, D. G., 2015. Average spectral

acceleration as an intensity measure for collapse risk assessment. Earthquake Engineering & Structural Dynamics, 44(12), 2057–2073. DOI: 10.1002/eqe.2575

Example

import numpy as np
from openquake.vmtk.imcalculator import imcalculator

acc = np.loadtxt("openquake/vmtk/tests/test_data/acceleration.txt")
im = imcalculator(acc, dt=0.005)

periods = np.linspace(0.1, 1.0, 10)
avg_sa = im.get_saavg_user_defined(periods=periods)
print(f"User-defined AvgSa = {avg_sa:.4f} g")