Deflection monitoring and assessment for a suspension bridge using a connected pipe system: a case study in China

Abstract

Summary This paper discusses the application of a connected pipe system (CPS) to a suspension bridge in China for the purpose of vertical deflection monitoring and assessment. The CPS mainly consists of three main parts: the pressure transmitters to detect the height change of liquid, the pipes to connect the reference point and measurement points, and the liquid to fill the connected pipes. Multiple pressure transmitters, taken as the measurement point, were mounted inside of the girder. A reference transmitter was mounted inside of a tower, taken as a fixed point. To verify the performance and reliability of the CPS, a controlled load test after the completion of the bridge construction and an uncontrolled load test under the actual traffic loading were carried out. The results showed that the CPS exhibited excellent capability in real‐time measurement of vertical deflection of the suspension bridge. With the long‐term deflection data monitored by the CPS, the extreme deflections with respect to vehicle loads were predicted by extreme value analysis. The generalized extreme value distribution was adopted to establish the probability models of the daily maximum and minimum deflection sequences, and then the extreme deflections within the design reference period of 100 years were determined based on the probability models. Comparison of the extreme deflections and the deflection thresholds was carried out. The deflection monitoring and assessment method proposed in this paper have shown high potential of applicability in the practice of health monitoring for long‐span bridges. Copyright © 2015 John Wiley & Sons, Ltd.

Serviceability assessment for long-span suspension bridge based on deflection measurements

“…Identification of traffic‐induced deflection includes two substeps: (a) elimination of temperature‐induced component from the original measurements and (b) extraction of local extremes of the traffic‐induced deflection. Vertical deflection of long‐span bridges is typically composed of three components including temperature‐induced deflection, traffic‐induced deflection, and noise‐induced pseudodeflection . The components induced by temperature and noise should be eliminated from the raw deflection measurements to obtain the deflection component caused by traffic.…”

“…With the rapid developments of structural health monitoring system (SHMS) techniques, the deflection caused by live load for in‐service bridges can be studied based on high‐quality monitoring data from advanced deflection sensing systems. During the past years, various deflection sensing systems have been developed, and a large amount of monitoring data of bridge deflection become available, such as GPS, noncontact vision sensors, interferometric radar systems, and connected pipe systems (CPSs) . Similar to other collected data from SHMS, a major challenge still remains in terms of how to effectively utilize the monitoring data of bridge deflection under live loads to improve the knowledge about the bridge performance and design.…”

“…First, an accurate and continuous deflection monitoring technique for long‐span bridges needs to be carefully selected to provide reliable monitoring data . In addition, how to develop an appropriate reliability model with monitored deflection data from multiple sensors also deserves further investigation . This study presents a deflection assessment framework of long‐span bridges based on the long‐term monitoring data from an advanced deflection monitoring system.…”

First-passage probability of the deflection of a cable-stayed bridge under long-term site-specific traffic loading

“…The WIM system has been working since the bridge was opened to the public in May 2012. Details of the WIM system can be found in Liu et al 26 Before statistical analysis of the measurements, a filtering process was conducted in order to identify and remove invalid records from the database. These criteria to identify the invalid records are as follows: (1) the GVW is \30 kN, (2) the axle weight is .300 kN, (3) the vehicle length is .20 m, and (4) the data are uncompleted or flagged with the system error.…”

Structural Health Monitoring and Time-Dependent Effects Analysis of Self-Anchored Suspension Bridge with Extra-Wide Concrete Girder

“…Raeisi [21] developed a new low-cost and accurate binary sensor comprised of wire bonded onto the girder using an adhesive to detect cracks in steel girders. A connected pipe system was used in the vertical deflection monitoring for a suspension bridge in China [22]. The fiber optic sensor [23,24], acoustic emission technique [25], and ultrasonic monitoring technique [26] are also important tools in SHM field.…”