Search results for "Isolation system"
showing 9 items of 9 documents
Upwards - Vertical extensions of masonry built heritage for sustainable and antifragile urban densification
2021
Abstract Urban densification represents one of the biggest universal challenges of contemporary cities: the increase of urban population requires new spaces to accommodate the growing demand for housing, working and tertiary activities. However, the land available for new constructions in highly urbanized areas is very limited. In this framework, the vertical extension of existing buildings is the most sustainable strategy and fascinating. Masonry structures , constituting a major part of the built stock in the historical city centres of several European countries, are particularly suitable for vertical addition of extra-floors, since they generally exhibit an adequate overstrength for bear…
Coupling of Structural Additions for the Mitigation of Seismic Response in Existing Buildings
2023
In the present paper, additions in structural steelwork are utilized for giving new life to old buildings in regions characterized by medium/high seismic hazard. Two models are here proposed, i.e.: vertical addition for masonry buildings and lateral addition for r.c. buildings. For the model of vertical addition, the connection between the masonry and steel structures is realized by means of an Intermediate Isolation System (IIS). For the model of lateral addition, an exoskeleton (EXO) is connected to the existing building by means of rigid or flexible and dissipative link. Two buildings, representative of the heterogeneous Italian building stock, are selected as case studies. Parametric an…
Intermediate Isolation System with Nonlinear Lower Structure and Isolation System
2023
This paper reports a study on the Intermediate Isolation System (IIS) applied to existing buildings. This kind of application is particularly suitable when a vertical addition is planned for buildings in seismic zones; in such a case, an isolation system can be placed at the base of the extension to prevent the increase, or, better, to reduce the seismic demand on the existing structure. In previous works, parametric response spectrum analyses have been carried out on lumped mass models by varying the period of the isolation system. As a result, a sort of IIS design spectrum has been derived and used for selecting design solutions for the vertical extension that minimize the overall seismic…
Assessment of the tuned mass damper inerter for seismic response control of base‐isolated structures
2020
In this paper, the hybrid control of structures subjected to seismic excitation by means of tuned mass damper inerter (TMDI) and base-isolation subsystems is studied with the aim of improving the dynamic performance of base-isolated structures by reducing the displacement demand of the isolation subsystem. The seismic performance of TMDI hybrid controlled structures is investigated in a comparative study, considering simple isolated systems and systems equipped with other absorber devices such as the tuned mass damper (TMD) and the tuned liquid column damper (TLCD). The TMDI has been optimized by performing a simplified approach based on minimizing the base-isolation subsystem displacement …
Simplified analytical solution for the optimal design of Tuned Mass Damper Inerter for base isolated structures
2019
Abstract In this paper the use of the Tuned Mass Damper Inerter (TMDI) to control the response of base isolated structures under stochastic horizontal base acceleration is examined. Notably, the TMDI, recently introduced as a generalization of the classical Tuned Mass Damper, allows to achieve enhanced performance compared to the other passive vibration control devices. Thus, it represents an ideal alternative for reducing displacements of base isolated structures. To this aim, firstly a straightforward numerical approach is developed for the optimal design of this device considering a white noise base excitation. Further, a simplified analytical solution for the optimal design of TMDI para…
Smart structures through nontraditional design of Tuned Mass Damper Inerter for higher control of base isolated systems
2020
Abstract This paper introduces a smart structure design through the definition of an innovative passive control strategy, referred to as New Tuned Mass Damper Inerter (New TMDI), coupled with a base isolation system (BI), to control displacements in base isolated structures under seismic excitations. The herein proposed New TMDI comprises a recently developed nontraditional Tuned Mass Damper (known as New TMD), in which a secondary mass system is connected to the base plate of the BI system by a spring and to the ground by a dashpot, and of an inerter device placed in parallel with the damper. An optimization procedure which minimizes the base displacement variance of the BI system, conside…
A variant design of Tuned Mass Damper Inerter for reducing displacements of base isolated structures
2021
In this study an innovative passive control strategy, referred to as New Tuned Mass Damper Inerter (New TMDI), coupled with a base isolation system (BI), is presented with the aim of reducing displacements in base isolated structures subject to seismic actions. The proposed New TMDI employs the synergetic benefits of a recently developed non-traditional Tuned Mass Damper (known as New TMD) and an inerter device to achieve higher control performances in isolated structures. Specifically, the New TMD is a secondary mass system connected to the BI system by a spring and to the ground by a dashpot. In addition, in the New TMDI configuration, the inerter device is placed in parallel with the dam…
INNOVATIVE MASS-DAMPING-BASED APPROACHES FOR SEISMIC DESIGN OF TALL BUILDINGS
2021
Mass damping is a well known principle for the reduction of structural vibrations and applied in tall building design in a variety of configurations. With mass usually small (around 1% of building mass), the properly “tuned” mass damper (TMD) shows great effectiveness in reduc-ing wind vibrations, but minor advantages under earthquake excitations. The above limitation can be surpassed by utilizing relatively large mass TMD. For this pur-pose, two different solutions are here proposed. In both cases, the idea is to separate the building into two or more parts, thus allowing for a relative motion between them, and acti-vating the mass damping mechanism. In the first solution, the building is …
Intermediate Isolation System for the seismic retrofit of existing masonry buildings
2022
This paper deals with the potentials of Intermediate Isolation Systems (IIS) for retrofitting masonry buildings by means of a vertical extension, isolated at its base, and realized on the rooftop of the existing structure. By carefully defining the dynamic properties of the superstructure and isolation system, in previous papers the authors have demonstrated that this passive technique is able to reduce a priori the seismic demand on the existing building. For this reason, the non-linear behavior has been only assumed for the isolation system, with the masonry structure in the elastic field. This result has been validated by carrying out spectrum-compatible time history analyses on the 3D F…