EROSION PROTECTIVE DEVICE Russian patent published in 2005 - IPC

FIELD: erosion control devices for road, hydraulic and irrigation and drainage construction.

SUBSTANCE: device comprises member to protect piers from local erosion which may move along the pier as total erosion develops. The member has curvilinear side walls provided with splitter enclosing the structure from both sides and made as a single while with immovable false bottom of artificial material so that entrapped flow part may be restricted in the region upstream of midlength pier section and may be expanded in the region between midlength pier section and end section. False bottom has transversal cross-sections with i_n inclinations to plane of symmetry. The cross-sections pass into ones having zero transversal inclination to plane of symmetry in midlength pier section. Below midlength section part of false bottom surface is symmetric to upper one. Side walls of false bottom are created in accordance with above relations, where y_j=y_j(X) - current transversal coordinate of curvilinear side wall, z_j=z_j(x) - current vertical coordinate: when 0≤x≤1; y_j(x)=b[1+x⁵(B/b-1)(21-35x+15x²)], when 1≤x≤2; y_j(x)=B[1+(x-1)⁵(B/b-1)[21-35(x-1)+15(x-1)²]], x=X/X₀, z(x)=z₀-i₀x, ; u·Δz·Δy = u₀·Δz₀·Δy₀, ;

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i_n=(∂z/∂y)(∂y/∂x)-(d²y/dx²)/(((∂²z/∂x²)/((∂y/∂x)²)+(∂z/∂x)²))+1/(u²/gX₀)), here X is dimensional longitudinal coordinate, X₀ - half of the area, x is dimensionless coordinate; B in initial width, b is width in midlength pier section, y_j(x) is bottom streamline map, z(x) is longitudinal profile of border streamline; z_bottom(x)=Z(x)-h, i₀ is longitudinal water channel bottom inclination; i_n is transversal false bottom inclination; h is current flow depth in vertical direction; H is initial depth of approach flow; u₀ is current velocity in initial section; u is current velocity in arbitrary point; Ψ =10 - number of calculation layers of flow part.

EFFECT: decreased costs, increased safety and operational reliability of the structures.

6 dwg