departmental bulletin paper

In this study, a novel VR-based system for inspection of deteriorating concrete bridges is proposed to support of the crack and spalling detection which is a key role in existing bridge maintenance. The proposed system, called a VR-based support system for bridge inspection, was applied to an aged bridge for confirming the representing ability of both cracking and spalling damages as a specific example. Experimental results showed that the VR images data with hammering sounds (audio) data have a sufficient ability of representing both crack width over 0.2 mm and a certain spalling area near concrete surface. In this system, the three-dimensional image(photo) data was used to recognize the cracking damage for professional visual inspector. On the other hand, as spalling damage inside the concrete surface couldn’t be identified accurately from only image(photo) data, then the hammering sounds (audio) data was incorporated into the system as an additional function for recoginittion of the spalling damage.

In this study, as one solution to the problem for condition assessment of existing short- and medium-span reinforced/prestressed concrete bridges, a new monitoring method using a public bus as part of a public transit system (bus monitoring system) is proposed, along with safety indices, namely, characteristic deflection, which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter. A basic study was conducted by using the results of technical verification experiments and numerical analysis simulation. This paper describes the details of not only how to assess the bridge condition by public bus vibration measured in operating on Ube City bus network as a specific example for verify the system but also what kind of consideration we need to apply the system to existing bridges in overseas country. And, the degrees of abnormality of the monitored bridges were expressed with the "inspection necessity level" to enable local governments to prioritize their bridge maintenance needs quantitatively.