Open Collections

Dynamic analysis of bridges with laminated wood girders

University of British Columbia

The response of bridges due to loading by heavy vehicles is one of the important aspects of bridge design. The effects of traffic on the response are significant if the bridge is a short and light-weight structure and the vehicle is very heavy. This is the case of a loaded logging truck passing over a logging bridge. The passage of a vehicle over a bridge is a complex dynamic problem and, for simplicity, bridge design codes treat it in a pseudostatic manner. Generally, the codes require a static analysis of the bridge using a specified design truck. The static response of the bridge is then multiplied by a dynamic load allowance factor in order to account for the dynamic response. The timber industry is one of the most important in the province of British Columbia and transportation of its products is a significant part of this industry. Logging bridges made from wood form an important element of this transportation network and their optimal design is, therefore, of importance to the province. However, provisions of bridge design codes are mostly supported by investigations conducted on highway bridges. Such is the case of the new Canadian Highway Bridge Design Code (CHBDC), which is now being prepared in Canada for release in 1996. It is desirable, therefore, to investigate if the recommendations of CHBDC for wooden bridges correspond with the actual response of a logging bridge loaded with a passing logging truck. The objective of this study was to develop a tool to perform dynamic analysis of the system logging bridge - logging truck and to verify, that the dynamic load allowance factor from the CHBDC represents adequately the dynamic amplification factor obtained from dynamic analysis of the system logging bridge - logging truck. A numerical model to simulate the passage of a vehicle over a bridge was developed. The model was calibrated with results of ambient and forced vibration testing of an existing bridge. Finally, dynamic amplification factors were obtained from numerical simulations and compared with CHBDC provisions. The results of this study showed that these provisions are generally adequate for wooden logging bridges.

Thesis/Dissertation

application/pdf

2009-01-30

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/3996

Civil Engineering

University of British Columbia

UBCV

DSpace