Static and dynamic testing of bridges through microwave interferometry

“…A selective investigation campaign was carried out on materials and structural members, including on-site Son-Reb, pacometric and Vickers-type micro-durometer analyses, and laboratory tests on concrete and steel bar samples. On the basis of the prescriptions of Italian Standards [47,49], as well as of professional protocols [50,51], the tests met the basic knowledge level (named LC1 in [49]) for the structural assessment analysis of public buildings in Italy. The corresponding value of the confidence factor, i.e., the additional knowledge level-related safety coefficient to be introduced in stress state checks, is equal to 1.35.…”

Section: Geometrical and Structural Characteristics Of The Case-studymentioning

confidence: 99%

Energy-Based Design Criterion of Dissipative Bracing Systems for the Seismic Retrofit of Frame Structures

Terenzi

2018

Applied Sciences

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Featured Application: An energy-based sizing criterion is proposed to help designing dissipative bracing systems incorporating fluid viscous spring-dampers for the seismic retrofit of frame structures.Abstract: Direct sizing criteria represent useful tools in the design of dissipative bracing systems for the advanced seismic protection of existing frame structures, especially when incorporated dampers feature a markedly non-linear behaviour. An energy-based procedure is proposed herein to this aim, focusing attention on systems including fluid viscous devices. The procedure starts by assuming prefixed reduction factors of the most critical response parameters in current conditions, which are evaluated by means of a conventional elastic finite element analysis. Simple formulas relating the reduction factors to the equivalent viscous damping ratio of the dampers, ξ eq , are proposed. These formulas allow calculating the ξ eq values that guarantee the achievement of the target factors. Finally, the energy dissipation capacity of the devices is deduced from ξ eq , finalizing their sizing process. A detailed description of the procedure is presented in the article, by distinguishing the cases where the prevailing structural deficiencies are represented by poor strength of the constituting members, from the cases having excessive horizontal displacements. A demonstrative application to the retrofit design of a reinforced concrete gym building is then offered to explicate the steps of the sizing criterion in practice, as well as to evaluate the enhancement of the seismic response capacities generated by the installation of the dissipative system.

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“…Radar can be used for both static (Pieraccini et al 2007) and dynamical studies (Stabile et al 2013). Cable-stayed bridges can especially benefit from radar monitoring, with moderate time and cost recourses with respect to the use of conventional sensors.…”

Section: Vibration Measurement Of a Bridgementioning

confidence: 99%