Comparison of Bridge Inspection Methodologies and Evaluation Criteria in Taiwan and Foreign Practices

Abstract

-The reliability of structural performance of bridges in Taiwan are affected by both in-service loading and material deterioration due to extreme environmental factors. With an inventory of 27,895 bridges and culverts in Taiwan Bridge Management System (TBMS), there are more than 8,840 bridges that are over 30 years and around 8,877 whose built years are still unknown. Government officials noticed this issue in recent years and placed thoughtful attention. Not only did they establish the maintenance mechanism for regular bridge inspections and maintenance, but developed maintenance systems to upsurge the competence of bridge management. However, this strategy only focused on data recording and was not able to notably improve maintenance efforts. Thus, it is essential that engineers refine their inspection and assessment techniques.Bridge inspection data recorded in TBMS are frequently analysed, to determine failure causes. According to the "Validation of bridge inventory data in TBMS" project, funded by Ministry of Transportation and Communications (MOTC) in 2010, the accuracy of bridge inspection data was lower than that of inventory. Consequently, MOTC proposed to enforce a new and detailed inspection program after 2015.This research reviewed the state-of-the-art for inspection methodologies in practice to assess condition of bridges in Taiwan, Japan, South Africa, USA and Europe. Concisely, the findings, including description, categorization of deterioration, and assessment method of bridge conditions were collected to provide bridge inspectors and engineers with more reliable assessment approach. Recommendations for enhancing bridge inspection standards and qualifications for inspectors in Taiwan are also discussed in this paper accordingly.

Automated vision-based post-earthquake safety assessment for bridges using STF-PointRend and EfficientNetB0

“…Visual inspections of bridges are currently conducted in Taiwan using the DER&U system 4 developed by the National Freeway Bureau. This system assesses 21 standard components for all bridge types, with several additional components assessed in cable-stayed and arch bridges.…”

“…DER&U is a subjective technique because two defects may appear to the inspector to be the same and have the same extent, but the inspector’s judgment may differ. 4 The CI of a bridge is determined using all of the DER&U information to obtain the average deterioration value for all of the components. However, the process of averaging may cause seriously deteriorated crucial components to be overlooked and thus underestimate the need for repairs and the risk of collapse.…”

“…1 Because Taiwan is located in the seismically active Circum-Pacific Belt, 2 structural health monitoring (SHM) for bridges is necessary to ensure that bridges are appropriately maintained to avoid costly repairs or catastrophic collapse. 3 In Taiwan, SHM for bridges is currently conducted using the ''degree, extent, relevancy, and urgency'' (DER&U) system, 4,5 which, in addition to being time-consuming and laborintensive, generates inconsistent results due to differences in inspector experience and perception. 6 Because of the time-sensitive, multisite nature of SHM work following an earthquake incident, the DER&U system is inadequate.…”