No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

This research project is the second part of a research program carried out by Itagawa (2005) who studied the seismic response of a half-scale model of an existing Montreal bridge built in the 1960's. This project studies the seismic behaviour of the retrofit carried out on the frame structure studied in the first part of the research program. The retrofit was made following the requirements of the current Canadian Highway Bridge Design Code (CHBDC). The philosophy of the CHBDC is to provide flexural yielding in the ductile elements so that brittle failure modes such as shear are prevented. This capacity-design approach resulted in a ductile response and significant energy dissipation of the retrofitted structure. / The retrofit was designed in accordance with the CHBDC provisions. The cap beam and the beam-column joint regions were strengthened with a reinforced concrete sleeve containing additional transverse and longitudinal bars so that plastic hinging would form in the columns. This retrofit represents minimum intervention to improve the response of the frame. The retrofit frame was then subjected to both gravity loads and reversed cyclic loading to simulate seismic loading on the structure. The predictions of the response of the retrofitted frame provided reasonable estimates of first yielding in the column and the general yielding of the frame. Although the columns would not meet the requirements for ductile columns, they had sufficient shear strength and did exhibit a displacement ductility of about 2.3.

No description available.

M.Ing. (Civil Engineering) / Bridge design/analysis in South Africa is seldom done from the dynamic point of view, and then only .in most exceptional cases. The topic of dynamic behavior of bridges is fairly complex and not always well understood by the average design engineer. Until the advent of 3-D finite element packages, dynamic design was usually done by assuming behaviour of simplebeams and/orplatesandequating these to the real life situation. Thesevaluescan be found in standard designbooks and tables drawnup as a result of empirical studies and analyses done in the past The author felt that there was a need for a better understanding of the dynamic behavior of bridges and to develop skills in finite element modelling and analysis. He therefore undertook to investigate and study the dynamic behavior of the Bothasfontein interchange bridge. An empirical evaluation of the composite deck was developed using Finite Element Analysis, and the results compared with the actual behavior of the bridge. Good correlation between the model and the measured values was obtained.