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Experimental results on the nature-like fishway induced flow field and its relation to fish behaviour are presented. A rocky-ramp with 5% slope was built along a 8.9 m × 0.9 m × 0.6 m laboratory flume, and acoustic Doppler velocity measurements were taken in a grid with 186 points for low, middle, and high discharges. The flow is characterized applying spatial and point analysis techniques. Point analysis consistently shows that the boulder to boulder distance is small enough to disrupt turbulent coherent structures. At boulder wakes no predominance of sweep and ejection events occur, evidencing a good resting place for fish migration. The nature-like rocky-ramp offers a diversity of flow conditions controlled by the boulders geometry that might allow a variety of fishes to develop their preferred paths characterized by flow properties with different magnitudes depending on the particular species. Obtained results compare well with similar ones reported for other standard fishways. [ABSTRACT FROM AUTHOR]

The main cause of rockfill and embankment dam failures is overtopping due to insufficient outlet works. During the last 15 years, the Civil Engineering Department: Hydraulics and Energy of the Technical University of Madrid has been studying the overtopping failure process of rockfill dams. One of the aims of this research is to develop design criteria of cost-effective rockfill dam protections to avoid failure due to such overtopping. Among the different types of known protection, this analysis has focused on downstream rockfill toes. The objective of this study is to achieve stability of the downstream shell of rockfill dams to prevent mass slides. This article summarizes the results of the preliminary experimental and numerical tests developed during the year 2008. Preliminary conclusions show the feasibility of this protection to mitigate partially or totally the serious consequences of overtopping in rockfill dams. [ABSTRACT FROM AUTHOR]

Stone matrix asphalt (SMA) is a gap-graded mix that contains a high concentration of coarse aggregate, thereby maximizing stone-to-stone contact in the mixture and providing an efficient network for load distribution. Coarse aggregate particles are held together by a rich matrix of mineral filler and stabilizer in the thick asphalt film. This paper presents details on the laboratory studies carried out on stone matrix asphalt (SMA) mixtures with natural fibres and crumb rubber modified bitumen (CRMB). Indirect tensile strength, retained stability, resistance to moisture susceptibility, resistance to rutting, resistance to creep, and resistance to permeability and aging were found to improve with SMA mixtures with CRMB when compared with SMA mixtures with fibres as stabilizers. [ABSTRACT FROM AUTHOR]