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Riprap upgrade at WAC Bennett Dam in Canada
Published in Jean-Pierre Tournier, Tony Bennett, Johanne Bibeau, Sustainable and Safe Dams Around the World, 2019
G. Wu, K. Wellburn, M. Lawrence, F. Sadeque, L. Yan
The target design life for the new riprap is 50 years. In order to achieve the target design life, the new riprap is to have adequate quality and durability to withstand the northern climate at the dam, where annual temperatures typically range from -30 °C to +30 °C.
Field and model tests of riprap on steep slopes exposed to overtopping
Published in Journal of Applied Water Engineering and Research, 2019
Priska H. Hiller, Leif Lia, Jochen Aberle
Riprap consisting of large natural rocks or artificial elements is widely used to protect river banks, streambeds, bridge piers and abutments, dams, shorelines and other hydraulic structures against the impact of currents and waves (e.g. Abt and Johnson 1991; CIRIA et al. 2007; Abt et al. 2013; Chanson 2015; Jafarnejad et al. 2016). There exist two general riprap types, dumped and placed, which are constructed by either dumping the riprap elements or placing them in an interlocking pattern. The construction of placed riprap is more cost- and labour-intensive than simply dumping elements (Peirson et al. 2008), but placed riprap can withstand higher discharges than dumped riprap constructed with the same stone size (Larsen et al. 1986; Peirson et al. 2008; Hiller et al. 2017), especially on steep slopes (Dornack 2001).
Displacements as failure origin of placed riprap on steep slopes
Published in Journal of Hydraulic Research, 2018
Priska H. Hiller, Jochen Aberle, Leif Lia
Riprap is a common measure to protect shorelines, streambeds, river banks, dams, bridge piers and abutments as well as other hydraulic structures against erosion (e.g. Abt & Johnson, 1991; Abt, Thornton, Scholl, & Bender, 2013; Chanson, 2015; CIRIA, CUR, & CETMEF, 2007; Jafarnejad, Franca, Pfister, & Schleiss, 2017). It is defined as a permanent and erosion-resistant ground cover of large elements such as natural rocks or artificial elements to secure subjacent layers against the impact of hydrodynamic forces due to currents and waves. Riprap can be exposed to wave action or currents either perpendicular or parallel to the slope, and the elements forming the riprap can either be dumped or placed one by one in a specific pattern. These two construction methods define dumped riprap and placed riprap, respectively. Compared to dumped riprap, placed riprap is both more cost- and labour-intensive during construction. On the other hand, placed riprap offers specifically at steep slopes a higher stability in comparison to dumped riprap (Dornack, 2001).
The local scour around bridge piers—a review of remedial techniques
Published in ISH Journal of Hydraulic Engineering, 2022
Ningombam Bishwajit Singh, Thiyam Tamphasana Devi, Bimlesh Kumar
Using bed armoring countermeasure devices the streambed resistance can be significantly enhanced. They serve as physical barrier withstanding the shear stresses imparted by flowing water. Riprap is often the countermeasure of choice for bed armoring. In some areas laying riprap stones may not be feasible due to unavailability of durable stones. And in cases where it is readily available, the range of the stone size may not be suitable to provide necessary protection against scour or may be quite expensive to use. Other alternatives to riprap include articulating concrete block, concrete armor units, gabions, etc.