A novel interpretation of responses recorded during several shaking table tests allow a better under- standing of the effects on responses due to different strengthening interventions
Available in Italian only.
Month: October 2006
Experimental definition of shear deformation and strength for masonry panels
The paper shows the results obtained during experimental campaign of diagonal compression tests in Tuscany, in which a significant number of masonry panels were tested. The aims of this research are mainly two. On the one hand the authors compare medium values of shear strength and shear stiffness varying the knowledge level proposed in the OPCM 3431 code (LC1, LC2 and LC3). On the other hand, the authors verify shear strength and stiffness range value, given by OPCM 3431 code for masonry typology most recurring in Tuscany (Italy).
Available in Italian only
Ultimate limit state resistance of R.C. sections subjected to axial force and uniaxial bending moment
In this paper, the ultimate limit state resistance of RC sections subjected to axial force and uniaxial bending moment is evaluated, both by means of non linear analyses, which take into account the effect of the confining reinforcement and the degradation of the concrete in the post-elastic range, and according to the Italian code, i.e. considering a stress-strain curve for the concrete with an ultimate compressive strain of 3,5‰ and a design value of compressive strength equal to the characteristic value reduced by means of two factors: the partial safety factor and a coefficient taking account of long term effects and of unfavourable effects resulting from the way the load is applied.
The partial factor values adopted for the fundamental combination (gc = 1,6 for concrete and gs = 1,15 for steel) must be applied also for the seismic design so as to take into account the possible strength degradation of the materials due to the cyclic deformations. The adoption of these values and of the factor for long term effects, equal to 0,85, affects the evaluation of the bending resistance and, consequently, the cross section design. To evaluate the influence of these factors on the resistances, the latter are also calculated varying the design value of the concrete compressive strength.
A comparison between the resistances computed in the aforementioned ways is performed, evaluating also the influence of different parameters, such as the cross sectional dimension, the ratio between bending moment and axial force, the amount of longitudinal and transversal reinforcement.
Available in Italian only
Compressive response of high strength R.C. columns
An analytical model for the determination of the compressive response of R.C. members having circular transverse cross-section and reinforced with traverse steel and longitudinal bars is presented. The model able to include also the contribution in confinement due to transverse and longitudinal bars was verified against experimental data recently generated by the authors and those available in the literature. Also comparison was made with the predicted values given with recent models presented in the literature. Finally, a comment on the design prescriptions given by International, European and National codes in relation with the results here obtained is made.
Available in Italian only
Shear performance of clay tile masonry walls: comparison between experimental and numerical response
In the present paper the results of an experimental study for the mechanic characterization of clay tile masonry walls under shear forces are discussed. Further in the paper the reliability of the models for the prediction of the mechanic characteristics under shear forces proposed by some codes is verified. Diagonal tests have been carried out; then the relationship of the Italian and European codes, correlating the mechanical properties of the components and the normal compression mechanical property of masonry to its shear mechanical properties (strength and elastic modulus), have been verified. This control has requested also normal compression tests on masonry walls made of the same blocks used for diagonal tests, on the blocks themselves and on the used mortar.
Available in Italian only.
New passive control strategy for seismic upgrade of essential buildings: base isolation and tuned mass damping
A new passive control strategy, which combines base isolation and tuned mass damping to retrofit essential buildings, is herein discussed. In particular, the hypothesis of application of this strategy on Villa d’Agri’s Hospital (PZ) is presented. The effectiveness of the proposed approach has been evaluated in comparing linear and non linear seismic response of the isolated system, with and without TMD, to recorded accelerograms. The BI&TMD combined control strategy reduces displacements at the base without affecting the beneficial effects of isolation on the superstructure seismic response. Numerical results show higher control strategy effectiveness in the case of seismic excitations with high energy content in a low frequency range.
Available in Italian only