Search

As part of Main Roads Western Australia’s (MRWA) bridge management and bridge upgrading program, MRWA bridge no. 3014 was assessed to evaluate its condition before and after strengthening works with carbon-fiber-reinforced-polymers (CFRP). The assessment process coupled analytical results with field observations and dynamic testing of the structure. Vibration-based structural assessment of the bridge was conducted before and after the completion of the upgrading works. This paper presents the results of the vibration tests and modal analysis performed before and after the structure upgrading. In particular, the change in the structural properties and stiffness, before and after the strengthening, based on the analyses of the updated models of the bridge, is presented and discussed. The results demonstrate the effectiveness of using the dynamic assessment method to determine the elastic flexural stiffness of bridge structures retrofitted with CFRP. [ABSTRACT FROM AUTHOR]

In this study, the basalt rock extracted from the Kalgoorlie region of Western Australia is intensively studied on its compressive properties under both static and dynamic loads covering strain rate between 2.22 × 10-6/s to 408/s. The ultimate compressive strength and corresponding failure strain are quantified. The test results show that Kalgoorlie basalt rock exhibits high sensitivity to strain rate effect on its compressive strength especially above 100/s and dynamic increment factor up to 2.3 at strain rate 403/s. The failure strain also shows dependency to high strain rate. Discussion is made on fragment analysis which found the natural heterogeneous and anisotropic of WA basalt rocks cause variations on its compressive strength and dependent on the failure angle of the joints (layer formation). The dynamic increase mechanism on material compressive properties is observed to be correlated to the failure crack path formation, which can be explained through the fracture process captured from high-speed camera images analysis. Comparisons are also made on rock strengths with others' test data. A novel method based on numerical modelling is introduced which removes the influence of lateral inertia effect and specimen end friction effect out of the laboratory testing results. The true dynamic increase factor (DIF) for Kalgoorlie basalt rock at different strain rates are derived for more accurate analysis and design. [ABSTRACT FROM AUTHOR]