Experimental study on hydraulic characteristics of new ecological slope protection structure

Abstract

Bank slopes are an important part of river ecosystems. In recent years, a series of ecological engineering projects with ecological functions have been implemented in the middle and lower reaches of the Yangtze River. In this study, we designed a new type of ecological slope-protection structure for rivers. Through physical model tests, the hydraulic characteristics of the structure, such as velocity, turbulence intensity, and Reynolds stress, at different test conditions were analyzed. These characteristics were then compared with those of an open channel with vegetation. The distributions of hydraulic properties determined in the open-channel tests involving the new structure were similar for different experimental conditions. Velocity and turbulence intensity are hyperbolic along the normal direction, whereas the Reynolds stress is close to zero. Several inflection points were observed in each distribution of hydraulic properties. The inflection point at the top is due to variations in the water flow conditions. On the outside, a second inflection point occurs because the water flow fluctuates violently near the new structure. The distribution of hydraulic properties in the far water layer is similar to that observed in a soft bed test. This study provides foundational knowledge for the future development of ecological slope-protection structures.

Highlights

• A new ecological slope-protection structure is proposed.

• The distribution of hydraulic characteristics of an open channel with the new structure is analyzed.

• The zoning of shore slopes for the construction of the new structure is presented.

• The hydraulic characteristics of an open channel with the new structure and of an open channel with vegetation are compared.

Keywords:

• New structure
• hydraulic characteristic distribution
• inflection point
• division of hydraulic characteristics

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Key Research and Development Program Project (NO. 2018YFB1600400).