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Seismic Response in Pyramids of the Chichén Itzá Area, México

Description: 

We analyzed the seismic response of three archaeological structures in the Chichén Itzá area, Yucatán, Mexico, to provide elements that track their preservation. We measured ambient seismic noise with broad-band seismographs for three days, and we used the HVSR method and transfer functions to quantify vibration frequencies. The results show that the site frequency is 1.3 Hz. However, in the pyramids under study, especially the Kukulkan Pyramid, also called The Castle, the fundamental frequency is 5.1 Hz with a relative amplification of around 6. Our results show that the pyramids behave like soft soil on a rigid layer. In the case of the Kukulkan Pyramid, the noise recording at its base allows us to observe an effect of kinematic interaction due to the difference in rigidity between the subsoil and the structure. We did not observe any directional effect on HVSR curves due to the internal anisotropy of the pyramids. The estimated internal shear velocity is 255 m/s (considering the seismic response is of topographic origin). This velocity corresponds to non-compact materials resting on competent substratum with velocities larger than 1000 m/s, materials that are susceptible to stress changes that may eventually lead to structural deterioration. The findings of this study suggest that continuous monitoring and instrumentation of the lower levels is needed to evaluate the influence of sub-structures during the pre-construction stages and to determine whether there are other effects due to the karstic nature of the subsoil.

Session: Integrative Assessment of Soil-Structure Interaction and Local Site Effects in Seismic Hazard Analysis [Poster Session]

Type: Poster

Date: 5/3/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Martin

Student Presenter: No

Invited Presentation: 

Authors