Influencia de la superestructura en los empujes dinámicos del suelo sobre muros de subterráneos
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Date
2025
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Abstract
El presente trabajo tiene por objetivo analizar la influencia de la respuesta dinámica de la superestructura en los empujes dinámicos que el suelo ejerce sobre los muros de los subterráneos de edificaciones. Este estudio busca aportar al entendimiento del comportamiento sísmico de estas estructuras en contextos urbanos de alta sismicidad, donde las aproximaciones tradicionales pueden subestimar las solicitaciones al omitir la interacción suelo–estructura.La metodología se basó en el desarrollo de modelos numéricos tridimensionales en OpenSees, considerando edificaciones con 2, 4 y 7 niveles de subterráneo, con y sin una torre de 20 pisos en la superestructura. Se emplearon distintos tipos de suelo (Arena de Concón, Grava de Santiago y Arena de Nevada) con los cuales se llevaron a cabo 48 simulaciones dinámicas utilizando registros sísmicos reales y experimentales. Este enfoque permitió estudiar el “efecto torre”, el nivel de confinamiento y la rigidez estructural en los empujes sísmicos.Los resultados muestran que la superestructura puede incrementar de forma significativa los empujes dinámicos, particularmente en suelos menos competentes. Asimismo, un menor nivel de confinamiento (menos subterráneos) produce, en términos relativos, mayores solicitaciones. Las comparaciones con teorías clásicas (Mononobe-Okabe, Wood y Seed & Whitman) y con la norma chilena NCh433 revelan que dichas aproximaciones tienden a subestimar los empujes sísmicos. Finalmente, se identificaron fenómenos de resonancia entre las frecuencias del sismo y del sistema suelo–estructura, los cuales amplifican las demandas dinámicas. Estos hallazgos destacan la necesidad de incorporar explícitamente la influencia de la superestructura en el diseño sísmico de muros de subterráneos.
This thesis aims to analyze the influence of the dynamic response of the superstructure on the dynamic earth pressures exerted by the soil on basement walls of buildings. The study contributes to the understanding of the seismic behavior of these structures in highly seismic urban contexts, where traditional approaches may underestimate demands by neglecting soil–structure interaction.The methodology was based on the development of three-dimensional numerical models in OpenSees, considering buildings with 2, 4, and 7 basement levels, with and without a 20-story superstructure. Different soil types (Concón Sand, Santiago Gravel, and Nevada Sand) were employed, leading to 48 dynamic simulations using real and experimental seismic records. This approach allowed for the assessment of the “tower effect,” the confinement level, and structural stiffness on seismic earth pressures.The results show that the presence of the superstructure can significantly increase dynamic earth pressures, particularly in less competent soils. Likewise, a lower confinement level (fewer basements) leads, in relative terms, to higher demands. Comparisons with classical theories (Mononobe-Okabe, Wood, and Seed & Whitman) and the Chilean seismic code NCh433 indicate that these approaches tend to underestimate seismic earth pressures. Finally, resonance phenomena between earthquake frequencies and the soil–structure system were identified, amplifying dynamic demands. These findings highlight the need to explicitly incorporate the influence of the superstructure in the seismic design of basement walls.
This thesis aims to analyze the influence of the dynamic response of the superstructure on the dynamic earth pressures exerted by the soil on basement walls of buildings. The study contributes to the understanding of the seismic behavior of these structures in highly seismic urban contexts, where traditional approaches may underestimate demands by neglecting soil–structure interaction.The methodology was based on the development of three-dimensional numerical models in OpenSees, considering buildings with 2, 4, and 7 basement levels, with and without a 20-story superstructure. Different soil types (Concón Sand, Santiago Gravel, and Nevada Sand) were employed, leading to 48 dynamic simulations using real and experimental seismic records. This approach allowed for the assessment of the “tower effect,” the confinement level, and structural stiffness on seismic earth pressures.The results show that the presence of the superstructure can significantly increase dynamic earth pressures, particularly in less competent soils. Likewise, a lower confinement level (fewer basements) leads, in relative terms, to higher demands. Comparisons with classical theories (Mononobe-Okabe, Wood, and Seed & Whitman) and the Chilean seismic code NCh433 indicate that these approaches tend to underestimate seismic earth pressures. Finally, resonance phenomena between earthquake frequencies and the soil–structure system were identified, amplifying dynamic demands. These findings highlight the need to explicitly incorporate the influence of the superstructure in the seismic design of basement walls.
Description
Tesis (Magíster en Ciencias de la Ingeniería)--Pontificia Universidad Católica de Chile, 2025
Keywords
Superestructura, Empujes dinámicos, Subterráneos, Interacción suelo–estructura, Superstructure, Dynamic earth pressures, Basements, Soil–structure interaction