Mauro Mezzina

Designing Simply Supported R.C. Bridge Decks Subjected to In-Plane Actions: Strut-and-Tie Model Approach

The evaluation of the effects of seismic action on the decks of multi-girder bridges is often neglected by practitioners because it is thought that seismic code prescriptions (i.e., deck elastic behavior and minimum reinforcement) in addition to ultimate limit state reinforcement dimensioning for permanent and variable load, do not justify more accurate analyses aimed at checking and/or optimizing reinforcement layout. With the aim of verifying the reliability of this kind of approach, this article proposes a step-by-step procedure, based on the Strut-and-Tie Model, for the design of R.C. girder bridge decks subjected to in-plane seismic actions. As a first application, the proposed approach is used for a single span girder bridge deck. The influence on the model of geometry and supports of the bridge deck as well as the layout of girders and cross-beams is also investigated.

Reinforced Concrete Constructions at the Beginning of the 20th Century: Historical Review and Structural Assessment

Many reinforced concrete buildings and constructions belonging to the early 20th century can be found in European cities. Unfortunately, in most cases these pieces of work so rich in historical, architectural and cultural significance urgently require maintenance and restoration.

SIMPLIFIED CLOSED-FORM SOLUTION FOR THE DETERMINATION OF THE MOMENT-CURVATURE RESPONSE OF A CIRCULAR RC SECTION

A seismic vulnerability analysis of a multi-span simply supported bridge is often based on the seismic response of the most critical pier. This response is influenced by different collapse modes (flexural, shear, second order effects, lap-splice of longitudinal bars or their buckling). Among these the flexural behaviour is important and it’s known if the equivalent plastic hinge length and the Moment-Curvature law of the fixed end are given. This paper provides a closed-form dimensionless solution to obtain a 5 point Moment-Curvature diagram for circular RC section. The solution is based only on three parameters: dimensionless axial force, mechanical percentage of longitudinal reinforcement, geometrical percentage of transversal reinforcement. A numerical example is presented to test the solution comparing it with a FEM analysis.