Residential buildings in Barcelona are mainly reinforced concrete buildings and unreinforced masonry buildings with particular features, typical of the customary constructive techniques of the city. The unreinforced masonry buildings of Barcelona have an average age of more than 60 years and were built without any consideration of the seismic hazard. The building used here as a typical example has six stories, 18.9 m by 24.5 m in floor and 24 m in height. For representing this typology, a six-story URM building with 18.9 m by 24.5 m in floor and 24 m in height has been selected.
To analyze the dynamic behaviour of the building we used TreMuri computer program (Galasco et al., 2002), which is an excellent tool to describe the nonlinear in-plane mechanical behaviour of masonry panels and to assess the expected damage on masonry buildings due to earthquakes. The macro element model consists of panels, simulating piers and architraves, connected by means of rigid
blocks. The macro element takes into account both the overturning mechanisms, related to cracking at the corners, and shear mechanisms by means of a damage model with friction. In this way a generic wall with openings can be described by means of a limited number of unknowns, involving few model parameters.
By using the TreMuri program, a push–over analysis was carried out by using a lateral loading pattern corresponding to the third mode of vibration of the structures. In this way, we obtained the capacity curve for the building and then, by using also the demand spectra the performance point of the structure was obtained. Considering a lognormal probability distribution, we finally obtained seismic
fragility curves for the building. These curves will be used in developing seismic damage scenarios for Barcelona.
Procedures and techniques for the study of the seismic behaviour of buildings base on existing computer programs are developed in this paper. SAP2000 non-linear computer program was used to design the building. STAC computer program was applied to consider the uncertainties in the mechanical properties of the materials and to perform Monte Carlo simulations; this program enables generating data samples for geometrical and the material properties of a structure considered as random variables. RUAUMOKO computer program was employed to assess the seismic behaviour of the structure by means of a non-linear static analysis, calculating its capacity spectra. BCSEC computer program calculates the interaction and the moment-curvature diagrams for each cross section of the
structural elements required as an input data by RUAUMOKO program.
A stochastic analysis of the capacity and seismic response was carried out and fragility curves were then obtained for a five stories framed building using a lognormal cumulative function, indicating the probability of reaching or exceeding a certain damage state, for a given seismic demand. The main application of these curves is found in the simulation of vulnerability and seismic risk scenarios for urban areas.
Complexity is a central problem in modern system theory and practice. The ability to study large complex systems is greatly enhanced by modern computing machinery. A theory of large-scale complex control systems is rapidly developing, supplying powerful tools that enable to solve effectively more and more practical problems in different areas. Potential motivating advantages for using decentralized control schemes are in the reduction of transmission costs within the feedback loop, in the increasing of the reliability of the control operation in case of sensor/actuator/controller failures, the reduction of overall computational effort and the ability of parallel implementation in real time. It is well known that the control of flexible structures represents a new, difficult and unique problem, with many difficulties in the processes of modeling, control design and implementation. This investigation presents an overlapping decentralized control design for a cable-stayed bridge benchmark which was proposed within the structural control community to design and compare control schemes. The cable-stayed bridge has two towers as main structural elements. This naturally suggests the overlapping decomposition of a finite element overall dynamic model into two subsystems sharing a common part. Each subsystem is formed by a tower, adjacent cables and a part of the deck. The common shared part is formed by the central part of the deck. The paper firstly describes the problem and the objectives of the control. Then the overlapping solution is proposed and the corresponding algorithm is shown. ISSN 1582-3024 Article no.25, Intersections/Intersectii, Vol.1, 2004, No.7, “Bridges’ World” The idea of decentralization of control has been numerically tested using a SIMULINK scheme and compared to the benchmark sample centralized control design using the LQG design.The performance of the overlapping decentralized control design has been assessed by means of given benchmark evaluation criteria, eigenvalue analysis and time responses. The dynamics of the closed-loop benchmark model with the overlapping local controllers exhibits an acceptable behavior though slightly worse than in the centralized case.