On the modelling of infilled RC frames through strut models

Infill panels largely affect the seismic response of framed constructions. The wide variety in their mechanical and geometrical features has produced many different models and assumptions in their analytical representation. In this paper the simplest and most diffuse analytical approach, based on the introduction of equivalent struts, has been checked. An overview is presented, focusing on the strut dimensions, strength and number. Two case-studies, taken by two different experimental campaigns, have been considered and reproduced. The obtained results have been compared to the experimental ones, and some parameters have been checked for selecting the model to use for analysis

Health monitoring of a bridge system using strong motion data

In this paper, the acceptability of system identification results for health monitoring of instrumented bridges is addressed. This is conducted by comparing the confidence intervals of identified modal parameters for a bridge in California, namely Truckee 180/Truckee river bridge, with the change of these parameters caused by several damage scenarios. A challenge to the accuracy of the identified modal parameters involves consequences regarding the damage detection and health monitoring, as some of the identified modal information is essentially not useable for acquiring a reliable damage diagnosis of the bridge system. Use of strong motion data has limitations that should not be ignored. The results and conclusions underline these limitations while presenting the opportunities offered by system identification using strong motion data for better understanding and monitoring the health of bridge systems

Modeling of layered timber beams and ribbed shell frameworks

A methodology for modeling multi-layered structures is presented. The formulation is easily utilized in the framework of existing structural analysis programs to compute internal forces and the global and local deformations of multi-layered structural members and systems. The methodology is fully applied and verified for the case of multi-layered timber beams with semi-rigid connections between the layers. The verifications are performed using both static experimentation and detailed computational modeling with linear and nonlinear finite element analyses. Extension to curved members is also included where emphasis is focused on residual stresses due to construction procedures of layered timber arches. Finally, experimental and computational demonstration of the methodology is given from timber ribbed shells where reasonable agreement between model predictions and experiments is illustrated. (C) 2002 Published by Elsevier Science Ltd

Seismic Response of a Historical Unreinforced Masonry Building Damaged in the 2014 South Napa Earthquake

Several unreinforced masonry buildings damaged during the 2014 South Napa earthquake, California, USA, were investigated after the earthquake. The numerical analyses conducted on a representative example are presented in this paper. The building is the Sam Kee laundry building, the oldest stone commercial building in Napa, built in 1875. The geometry of the building was accurately captured by a laser scanner. Using this geometry information and material data available in literature for similar buildings, a finite element model of the building was developed according to the equivalent frame approach and was subjected to nonlinear time history analyses. The investigated building was closely located to a strong motion station on Main Street, Napa, California. This record was used as seismic excitation input to the numerical model. Results of the conducted analyses accurately predicted the observed damage in the building which consisted of shear cracks and shear damage in the south and north walls and failure of piers from the east wall. Analysis results are used to describe the reasons of the observed damage