Analysis of the seismic bearing capacity of shallow foundations

Abstract

Manuscript Code: 0365 Date of reception/acceptation: 01jan2014/01aug2014Resumen En el contexto de la práctica ingenieril, el problema de la capacidad de soporte sísmica de fundaciones superficiales generalmente ha sido resuelto, de modo indirecto, ya sea considerando un incremento en las tensiones admisibles estáticas del suelo, asociado a la probabilidad de ocurrencia de un cierto evento sísmico de diseño, o bien adoptando un enfoque de tipo pseudoestático equivalente. Sin embargo, durante las últimas décadas se han desarrollado una serie de métodos analíticos que abordan directamente el problema desde el punto de vista sísmico. Este artículo presenta un análisis comparativo de tipo paramétrico entre diferentes métodos para estimar la capacidad de soporte sísmica de fundaciones superficiales corridas. Se consideraron métodos analíticos, desarrollados en el contexto de las teorías de equilibrio límite y análisis límite, y también procedimientos de diseño simplificados típicamente utilizados en la práctica. Los resultados obtenidos muestran un importante deterioro de la capacidad de soporte de la fundación en la medida que la aceleración máxima del sismo aumenta, lo cual pone de manifiesto la necesidad de establecer una medida de la confiabilidad asociada a los métodos de cálculo y factores de seguridad comúnmente usados para diseño sísmico. AbstractIn the context of engineering practice, the problem of the seismic bearing capacity of shallow foundations has been solved indirectly, either due an increase of the static allowable soil pressures related to the probability of occurrence of the design earthquake or by adopting an equivalent pseudo-static approach. However, during last decades, a series of analytical methods that directly address the problem from the seismic point of view has been developed. This paper presents a parametric comparative analysis of different methods for estimating seismic bearing capacity of shallow strip foundations. Analytical methods, developed in the framework of both limit equilibrium and limit analysis theories, and also simplified design procedures typically used in practice were considered. The results obtained show an important decrease of the bearing foundation capacity with increasing of the maximum earthquake acceleration, which highlights the need to obtain a measure of the reliability associated with both calculation methods and safety factors commonly used for seismic design.Palabras clave: Capacidad de soporte sísmica, fundaciones superficiales, terremotos, métodos analíticos, métodos prácticos.

Vertical and Lateral Displacement Response of Foundation to Earthquake Loading

“…The problem of the earthquake bearing capacity of shallow footing has been solved indirectly, either by an increase of the static allowable ground, pressures connected to the probability of occurrence of the design seismic or by adopting an equivalent pseudo-static procedure [7].…”

Innovative EC8-compliant solutions for selection of the optimum retrofitting scheme of buildings with special characteristics

“…This value was increased by 50% for seismic actions ( σ u,seism = 375 kPa). This increase was documented by the Greek seismic code of 1959 (Royal Decree on the Seismic Code for Building Structures, 1959), which was valid in Greece at the year of design of Building (1971), as well as by the literature (Peck et al, 1974; Tiznado and Paillao, 2014).…”

Comparative Analysis of Seismic Design Codes for Shallow Foundations Adhering to the Kazakhstani and European Approaches

“…Foundation systems are designed to ensure load transfer from superstructures to ground without considerable deformation. The design decisions for the structures are defined based on the capacity issues [18,19]. This section provides a detailed design procedure for determining the seismic bearing capacity of shallow foundations when adhering to Kazakhstani and European codes of practice.…”