Multi-Hazard Assessment of RC Bridges using Unmanned Aerial Vehicle-Based Measurements

Abstract

The structural performance of reinforced concrete bridges is crucial regarding the bridge safety. Monitoring the bridge performance under multihazard effects such as scour, and earthquake becomes even more important. Thus, the scour depth along the piers and piles of bridge substructures has to be measured and tracked consistently in order for reliable multi-hazard bridge behaviour predictions. A practical Unmanned Aerial Vehicle based scour measurement method was proposed to increase the measurement accuracy and reduce the implementation costs. This method has been used in shallow and clear-water riverbeds. The Boğaçayı Bridge was selected as the case study located at the Boğaçayı River in Antalya, Turkey, since it was exposed to stream and flood, induced scour in the previous years. In the study region, the amount of scour was determined with considerable accuracy, and the scour measurements were used for generating the Three-Dimensional Finite Element model of the bridge. The multi-hazard performance of the bridge was acquired by implementing nonlinear static analysis using pushover curves corresponding to various scour depths concentrated at some of the bridge piers. Therefore, a continuously updateable multi-hazard bridge assessment system was proposed, which was implemented in bridges under scour and earthquake effects, regarding Unmanned Aerial Vehicle based measurements.

Multi-temporal UAV based repeat monitoring of rivers sensitive to flood

“…This technique is shown as reliable and efficient for collecting surface data for streams and rivers (Micheletti et al, 2015). For river bathymetry modeling, the bathymetric data acquired from high-resolution UAV-derived images at shallow water were verified with real data and high correlation was obtained (Flener, 2013;Ozcan & Ozcan, 2018, 2019.…”

“…Since the UAV based measurement methods procure data at extremely high spatial resolution (centimeter scale), the measurement precision is comparable to traditional surveying techniques (Carrera-Hernández et al, 2020). The direct applications of UAV-based measurement methods related to elevation, aspect, and stream distribution was useful in surface investigations and in analyzing hydrologic response by means of river mapping and floodplain characterization (Rusnák et al, 2018), riverbank and floodplain surveying (Tamminga et al, 2015), scour monitoring in bridges (Ozcan & Ozcan, 2018;Ozcan & Ozcan, 2019), and DEM generation over various scales and landscapes (Gafurov, 2018). UAVbased measurements provide a data collection platform between the point (i.e.…”

UAV-based inspection of bridge and tunnel structures: an application review

“…Another emerging imaging-based application with UAVs is the displacement/deformation measurement techniques of bridge structure, e.g., photogrammetric computer vision [9], [83], [89], [97], [146] and digital image correlation (DIC) [79], [92]- [95], [148]. Despite these imaging-based techniques, it is also worth mentioning the use of Laser Doppler Vibrometers (LDV) in UAVs as a non-contact sensor to measure bridge displacements [84]- [86].…”

UAV-based evaluation of morphological changes induced by extreme rainfall events in meandering rivers

“…In recent years, fine topographic changes were examined by using orthomosaics and digital surface models (DSMs) which could be produced by remote sensing methods instead of classical terrestrial measurement techniques. In this context, the use of UAVs in conjunction with low-cost, user-friendly Structure from Motion (SfM) photogrammetric technique are highly suitable to produce high-resolution orthomosaics and DSMs depending on UAV flight altitudes and mounted camera systems [10][11][12][13]. Comparative studies considered in different geomorphic regions have shown that the accuracy of high-resolution topographic data derived from SfM is similar to those produced by traditional methods [14][15][16][17][18][19][20][21].…”