Abstract

This paper presents a survey of the numerical simulation of base isolation systems for the vibration control of
buildings and their equipment, primarilly against earthquakes. Base isolation has received much attention in
the recent twenty years and many buildings have been protected using this technology. The article focusses
mainly on the different numerical methods used in the analysis of base isolated buildings. The conventional
form of solving the equations of motion governing the seismic response of building structures with nonlinear
base isolation consists of using monolithic step by step integration methods. As an effcient alternative, static
condensation and block iterative schemes can be applied. The particularities of the equations of motion
of buildings equiped with various base isolation systems are described. The linear theory of base isolated
buildings is then presented. After this, numerical solution techniques for the analysis of the seismic response
of buildings with isolation systems are developed in detail in the paper. Finally, numerical results for elastic
and inelastic structures are described. A complete set of references coverning a wide range of studies is
included.

Abstract

The changes in the geometry of the structures are called irregularities and are divided into two types: plant and height irregularities, the latter being widely investigated. In this sense, the objective of the present work is to study in detail the influence of the plant irregularities in the seismic resistance of a reinforced concrete structure, to quantify and locate vulnerable zones in the structure. The proposed study is developed numerically using ETABS software Nonlinear v9.7.2 and MATLAB R2009b. The results showed that plant irregularities as they are placed in the structure, this is losing its bearing capacity and therefore its ability to withstand the lateral loads.

Abstract

In this paper a rate‐dependent isotropic damage model developed for the numerical analysis of concrete dams subjected to seismic excitation is presented. The model is shown to incorporate two features essential for seismic analysis: stiffness degradation and stiffness recovery upon load reversals and strain‐rate sensitivity. The issue of mesh objectivity is addressed using the concept of the ‘characteristic length’ of the fracture zone, to show that both the softening modulus and the fluidity parameter must depend on it to provide consistent results as the computational mesh is refined. Some aspects of the numerical implementation of the model are also treated, to show that the model can be easily incorporated in any standard non‐linear finite element code. The application of the proposed model to the seismic analysis of a large gravity concrete dam shows that the structural response may vary significantly in terms of the development of damage. The inclusion of rate sensitivity is able to reproduce the experimental observation that the tensile peak strength of concrete can be increased up to 50 percent for the range of strain rates that appear in a structural safety analysis of a dam subjected to severe seismic actions.

Abstract

Abstract

This work presents an application of a Building Information Model (BIM) to the National Palace of Sintra, Portugal, a large and complex building composed of different unreinforced masonry buildings that is included in the Cultural Landscape of Sintra, classified under the UNESCO World Heritage list in 1995. The developed H-BIM (Heritage Building Information Modelling) model has the ability to provide the geometric information of the structure of the building, together with its descriptive attributes, such as the mechanical characterization of the building materials, as inputs to the seismic structural analysis. The results of such analyses are also stored as attributes within the H-BIM model, providing an integrated platform usable by the building management. Geometric data was acquired using a Faro FocusS70, together with a Topcon Falcon 8+ UAV. The methodology applied in the construction of the H-BIM model was implemented with Autodesk Revit® software. Since the Palace is very complex, its seismic behaviour was studied for the different building units, considering the effect of the adjacent ones, and performing nonlinear static analyses through 3Muri software.