Encontrados 13 documentos, a visualizar página 1 de 2
The behaviour of single span stone masonry skew arches
Sarhosis, Vasilis; Oliveira, Daniel V.; Lemos, José V.; Sheng, Yong; Lourenço, Paulo B.The work reported in this paper summarises the development and results obtained from a 3D computational model, using the distinct element software 3DEC, that was used to investigate the effect of the angle of skew on the load carrying capacity of sixteen different single span stone masonry arches. The variables investigated in the research were the arch span, the span : rise ratio and the skew angle. In order t...
Hydromechanical analysis of masonry gravity dams and their foundations
Bretas, E. M.; Lemos, José V.; Lourenço, Paulo B.A numerical model for the hydromechanical analysis of masonry dams based on the discrete element method is presented. The dam and the rock foundation are represented as block assemblies, and a coupled flow-stress analysis is performed in an integrated manner for the entire system. Complex block shapes may be obtained by assembling elementary blocks into macroblocks, allowing the application of the model to situ...
Masonry dams : analysis of the historical profiles of Sazilly, Delocre and Rankine
Bretas, E. M.; Lemos, José V.; Lourenço, Paulo B.The significant advances in masonry dam design that took place in the second half of the 19th century are analyzed and discussed within the context of the historical development of dam construction. Particular reference is made to the gravity dam profiles proposed by Sazilly, Delocre and Rankine, who pioneered the application of engineering concepts to dam design, basing the dam profile on the allowable stresse...
3D stability analysis of gravity dams on sloped rock foundations using the limi...
Bretas, E. M.; Léger, Pierre; Lemos, José V.A convenient approach to performing stability analysis of concrete gravity dams is the so-called two dimensional ‘‘gravity method.’’ However, concrete gravity dams located in valleys with sloped rock foundation abutments behave as three-dimensional (3D) structures and are often able to share compressive and shear loads between adjacent monoliths, especially when shear keys are present. A general 3D limit equili...
Masonry gravity dams : a numerical application for stability analysis
Bretas, E. M.; Lemos, José V.; Lourenço, Paulo B.This work presents a numerical application for stability analysis of masonry gravity dams. From the geometrical dimensions, the material characteristics, hydrostatic loads and seismic loads, the application automatically determines the following results: thrust line for the dead weight load and the dead weight together with the other loads; stress diagram and safety factors for the failure of the damfoundation ...
Análise e reforço de barragens gravidade
Bretas, E. M.; Léger, Pierre; Lemos, José V.; Lourenço, Paulo B.; Ramos, José M.As barragens são estruturas que representam risco potencial elevado pois em caso de rotura podem causar perdas humanas e materiais importantes. Através da sua observação criteriosa e com recurso a modelos numéricos faz-se a avaliação de cenários de rotura, obtendo-se factores de segurança que servirão como critérios de decisão para acções de reforço e reabilitação. Neste contexto apresenta-se o caso de uma barr...
Analysis of a gravity dam considering the application of passive reinforcement
Bretas, E. M.; Léger, Pierre; Lemos, José V.; Lourenço, Paulo B.Small concrete gravity dams are sometimes built using passive steel anchors to enhance their stability for the applied loads. It is important to assess the amount of internal tensile and shear forces resisted by the anchors to verify their structural adequacy. This paper presents the application of the distinct element method to study the magnitude and distribution of internal anchor forces. Comprehensive param...
Avaliação de uma proposta de reforço de uma barragem gravidade
Bretas, E. M.; Léger, Pierre; Lemos, José V.; Lourenço, Paulo B.As barragens são estruturas que apresentam um risco potencial elevado, pelo que a sua fiabilidade deve ser avaliada continuamente através de um programa de observação. Com base nos dados recolhidos podem ser estudados possíveis cenários de rotura através de modelos numéricos. Descreve-se neste trabalho os principais cenários de rotura a serem considerados quando da avaliação de segurança de uma barragem gravida...
Simulación numérica de estructuras formadas con grandes bloques de piedra
Peña, Fernando; Lourenço, Paulo B.; Lemos, José V.Este artículo presenta el modelado numérico de estructuras formadas con bloques de piedra. Este tipo de estructuras se deben representar como formadas por bloques rígidos, en vez de considerarlas como estructuras continuas. El Método de los Elementos Discretos (MED) es una herramienta efectiva en el modelado numérico de bloques rígidos. Aquí se propone una nueva metodología para encontrar los parámetros requeri...
On the dynamics of rocking motion of single rigid–block structures
Peña, Fernando; Prieto, Francisco; Lourenço, Paulo B.; Costa, Alfredo Campos; Lemos, José V.This paper describes the behavior of single rigid-block structures under dynamic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four blue granite stones with different geometrical characteristics under free vibration, and harmonic and random motions of the base. In total, 275 tests on a shaking table were carried out in order to address the issues of re...
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