Long term application of bus monitoring system to short and medium span bridges and damage detection

Ayaho Miyamoto,Hisao Emoto,Hideaki Tanaka,Válter J G Lúcio

doi:10.1088/1742-6596/628/1/012037

Ayaho Miyamoto, Hisao Emoto + Show 2 more

Open Access

https://doi.org/10.1088/1742-6596/628/1/012037

Copy DOI

Abstract

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.

Highlights

In order to properly maintain numerous short and medium span bridges in Japan by conducting periodic inspections, it is necessary to develop an easy-to-use and efficient bridge monitoring system
The authors are developing a short and medium span bridge monitoring system for detecting deterioration in safety and other performance of existing bridges by use of under-rear-wheel-spring acceleration sensors installed on fixed-route buses (Miyamoto and Yabe 2012; Yabe, Isoda and Miyamoto 2011)
This paper presents the result of a three-year field test of the bus monitoring system conducted by using an in-service fixed-route bus in Ube City

Summary

Introduction

In order to properly maintain numerous short and medium span bridges in Japan by conducting periodic inspections, it is necessary to develop an easy-to-use and efficient bridge monitoring system. It can be seen that after data section size exceeds a certain limit, standard deviations do not change significantly thereafter This indicates that by the moving average method mentioned above, the variability of characteristic deflection values decreased and converged so that anomalies can be detected by observing such changes. On the basis of characteristic waveforms appearing on estimated deflection diagrams when the bus passes the joints of the bridge of interest, girder midspan (1) Extract data on vertical acceleration induced by bridge-crossing bus waveforms are estimated and determined by synchronizing different data sets. 5) Average estimated deflection Calculated characteristic deflection by averaging the deflection estimates shown in the graph obtained at Step (4) in the direction of time (Fig. 10)

Experiment results

Effect of artificial damage on characteristic deflection

Overview of Overseas Field Test

Reinforced concrete T-girder cantilever bridge

Findings

Conclusions