IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Sediment management and morphodynamics : Estimate of riverbed variation and pier scour by using a non-contact surface velocity radar
Estimate of riverbed variation and pier scour by using a non-contact surface velocity radar
Author : JIAN-HAO HONG(1), PO-HUNG YEH(2), HAN-CHUNG YANG(3) & CHIH-CHIANG SU(4)
ABSTRACT
Scour around bridge piers and along river reaches has long been an intrigue topic for researchers. Its development,
especially during floods or some other large hydrological events, has particularly received plenty of attention. Most
research focuses on either building a prediction model or developing a scour monitoring system. However, due to the
difficulties in obtaining scour measurements during floods or spontaneous simulations from numerical models, it always
poses a great challenge for the administrators or agencies in the right timing for bridge closure or re-opening. This study
conducted field measurements of bridge pier and channel bed scour at Mingchu Bridge which crosses the middle section
of the Choshui River in Taiwan. Numbed bricks and wireless tracers were used to measure the maximum scour depth
and temporal variations of the scour depths during floods. A surface velocity radar and a water-level gauge were also
installed on the bridge deck to obtain flow information. Scour data were collected separately during a monsoon and
Typhoon Matmo in 2014, with the respective peak flow discharges of 1,446 and 4,980m3/s. The corresponding maximum
general and pier scour depths reached 1.76 m and 2.53 m during the monsoon, and 3.245 m and 4.125 m during the
typhoon. A quick estimation algorithm for temporal variations of general scour depth was developed, based on the
effectively cumulative stream power concept and calibrated by using the field data. Temporal variations of total pier scour
depth then could be determined by superimposing the estimation on the local pier scour depth. By examining with the
data from these two events, the results showed reasonable agreement with the field measurements. With the quick
estimation developed in this study, it would be possible to install guidelines for river and bridge management. More field
data are needed to further test the reliability and capability of the proposed method, and a more robust scour monitoring
system shall be developed in the future.
File Size : 1,113,087 bytes
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Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Sediment management and morphodynamics
Date Published : 28/08/2015
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