Abstract—Bridges constitute an important part in the
infrastructural development of any nation by connecting the
regions and parts separated by water bodies and by providing
access to inaccessible areas. Scour around bridge elements is
one of the major causes of bridge failures and approximately
60 % of the bridge failures take place due to scour and other
hydraulic related issues. Researchers have devoted significant
time and attention towards this issue, but the research work is
mainly concentrated towards uniform sized sediments.
However, in nature no stream exists with truly uniform sized
sediments. Therefore it is essential to carry out research work
in non-uniform sediments. The main feature associated with
non-uniform sediments is the formation of an armour coat
which differentiates the non-uniform sediments from the
uniform sized sediments. The armour coat by its presence
prevents the scour up to certain velocity but once the armour
layer is dislodged, the scour depth starts increasing again and
becomes nearly equal to that of scour in uniformly sized
sediments. As evident from the open literature, the correlation
between the velocity of flow and stability of armour layer is yet
to be established. Thus, an experimental investigation has been
planned and experiments are being carried out in uniform flow,
unsteady flow in discrete steps and some non-uniformity in the
flow in the form of hydrographic run. The sediments used in
the study were collected from River Yamuna and nonuniformity
was generated by artificially mixing of sediments in
different proportions. The results of the experimental
investigation are being presented in this paper.
Index Terms—Armour layer, hydrographic run, nonuniform
sediment, unsteady flow.
The authors are with the Department of Civil Engineering, National
Institute of Technology, Kurukshetra, Haryana, India (e-mail:
anshulsikaira@gmail.com, setia@nitkkr.ac.in).
[PDF]
Cite: Anshul Yadav and Baldev Setia, "Armouring and Its Effects on Local Scour around a
Bridge Pier in Non-uniform Sediments," International Journal of Engineering and Technology vol. 10, no. 6, pp. 468-474, 2018.
