Abstract

This article evaluates the cyclic behaviour of a prototype of a precast ferrocement house, which is assembled using precast thin walls, in order to identify its structural parameters and propose a nonlinear dynamical model which is able to simulate the behaviour of those houses when subjected to seismic loading. For this purpose, a full-scale precast ferrocement house was tested under cyclic loading conditions. From the experimental results, the hysteretic behaviour, the elastic stiffness, the shear resistance, the maximum strength, the ductility, the energy dissipation, the equivalent damping and its coefficient of energy dissipation were assessed; those parameters are needed in order to evaluate the dynamic behaviour of ferrocement dwellings when subjected to earthquakes. At the end, the Bouc-Wen-Baber-Noori (BWBN) model of hysteresis was implemented. The model allowed performing the seismic evaluation of the precast ferrocement house under seismic activity.

Abstract

The standards make recommendations regarding the seismic loads, the simplified methods of structural analysis, the criteria that must be applied to ensure its good global seismic behavior, as well as the earthquake resistant design details that must be applied. The structural analysis procedures included in all the seismic design standards are based on concepts generally used in the static and dynamic analysis of structures. However, when considering the possibility of using simplified procedures of dynamic calculation and of formulas that allow approximating the values of the dynamic characteristics of buildings, the mentioned concepts are not explained in a clear way. For this reason, the present monograph analyzes the content of the earthquake-resistant design codes in relation to the calculation methods they propose, explaining the concepts of structural analysis that are applied in each case, with special reference to Spanish regulations in force, NCSE-02. In addition, this monograph deals with aspects of conceptual design, which provides qualitative descriptions of design solutions based on the designer's experience. In this phase, the structural typology, the plan form of the structure, the distribution of the masses in height and the rigidities are chosen, the organization of the resistant system is specified, etc. It should be mentioned that in many regulations the conceptual design is specified in rules that are not justified in the text. All this implies taking decisive decisions in the initial phases of the design of structures, which condition the seismic behavior of the structures to such an extent that all the subsequent calculations, as well as the design details that are applied, may not have the expected effect.

Abstract

This paper deals with the critical issue of structural collapses and introduce a novel interpretation of the concept of Structural Robustness applied to Intact and Damaged Frames in order to quantify the critical load multiplier in each case, by a simple set of mathematical equations.