The Mexico Earthquake of September 19, 1985—On the Seismic Response of the Valley of Mexico

Abstract

In order to explain damage and observed ground motions in Mexico City during the 1985 Michoacán earthquake, simultaneous consideration must be given to source, path, and site conditions. This is clear from teleseismic records and local vertical displacements. Incident waves had an important part of energy in the frequency band of 0.3-1 Hz. Damage distribution and observed motion in the lake bed zone cannot be satisfactorily explained using one-dimensional theory. The effects of lateral irregularities are required. To assess its effects we describe the stratigraphic setting of the valley and discuss some features of damage distribution with results for one- and two-dimensional wave propagation models. These are useful to establish on quantitative basis the importance of lateral heterogeneity.

Semi‐empirical model for site effects on acceleration time histories at soft‐soil sites. Part 1: formulation and development

“…A careful analysis of that information shows that the one-dimensional idealization of the response of the soft-soil formations does not lead to the increase in duration and amplitude that is typically observed at their surface [4]. The di erences have been attributed to three-dimensional e ects of the valley, to surface waves that are locally generated by the mechanical and geological heterogeneity of the soil deposits [5] and to the late arrival of waves following multiple paths from the source [6].…”

Relación De Atenuación Del Movimiento Del Suelo Para

“…En particular se dedujo una relación de atenuación para estimar la aceleración máxima del suelo (PGA, por sus siglas en inglés) para la trayectoria de Guerrero hasta Querétaro. El comportamiento de la fuente y su propagación tierra adentro hasta los márgenes del Cinturón Volcánico Mexicano (MVB) y con especial atención dentro del Valle de la Ciudad de México, ha sido muy estudiado por la variabilidad amplificativa que presenta el suelo, como ocurrió por el sismo del 19 septiembre de 1985 (e.g., Anderson et al, 1986;Sánchez-Sesma et al, 1988;Campillo et al, 1989;Kawase y Aki, 1989;Singh et al, 1989Singh et al, , 2000. Por otra parte los primeros en obtener parámetros que caracterizaron la atenuación en esta zona del Pacífico fueron: Rodríguez et al (1983), Valdés et al (1987), Singh et al (1988), Castro et al (1990), Rebollar et al (1991), Ordaz y Singh (1992), Domínguez et al (1997), Ottemöller et al (2002) y estudios más recientes como los de García et al (2005) y García (2006), englobando sismicidad intra e interplaca, respectivamente.…”

Polarization and Frequency-Wavenumber Spectrum Analysis for the Strong-Motion Array Data in Ashigara Valley, Japan.

“…In the area of soft sediments, strong motion at a period of 2-3 s was preferentially amplified and the strong shaking lasted for more than 120 s. The long duration of the observed motion in lake sediments cannot be satisfactorily explained by one-dimensional wave propagation theory, but a two-dimensional model offers a better course for interpretation (e.g., Kawase, 1987;Sanchez-Sesma et al, 1988;Bard et al, 1988;Kawase and Aki, 1989). The importance of long-period (1-15 s) strong motion has been recognized in the field of engineering seismology associated with the increasing number of high-rise buildings, suspension bridges, offshore structures and huge oil tanks.…”