| 摘要 |
FIELD: construction. ^ SUBSTANCE: transfer screen made of three parts: a vertical part, a broken part made of two sections, one of which is a retaining section of the broken part and is inclined to a windward side at the angle to the vertical part, and the second section - a boost section of the broken part, which is inclined towards the windward side at the angle to the vertical part of the screen. The screen is installed at the edge of a road surface, at the same time the transfer screen is arranged at the windward side, the minimum height h2 of the transfer screen, which ensures laminarity of snow drifting, is calculated using the formula h2=b/4-h, where h - height of a road fill (slope), b - width of the road surface, and the appropriate value of shift d of a cylindrical ellipse axis (Y) perpendicular to the road is calculated using the formula d=[2(h1Çè2-h2Çè2+2h(h1-h2)]/b, with the cylindrical ellipse radius R, which ensures snow drifting transfer over the road surface, where h1 - the specified height of the transfer on the opposite side of the road surface. The boost section of the broken part (A-C) is directed along the tangent to the ellipse passing through the upper point of the transfer screen, the minimum length 1 of the boost section in the broken part (A1-C) is calculated to ensure the specified function of snow drifting border shape in the form of the cylindrical ellipse described with the flow equation (a+d)+4y=R, where a - maximum axle of the ellipse, parallel to the road surface, and is calculated from the point of crossing of the underlying surface of the road slope base, y - coordinates of the ellipse axle Y, perpendicular to the road surface, and R - radius of the ellipse, and with the condition that the minimum height of the transfer screen (D-C1) is equal to (h2 - 0.3 m), making at least 1-0.3 m sin, where - angle between the tangent to the ellipse and the road base, and - angle to the vertical part of the screen in the retention section of the broken part (A-B), makes not more than 90 and not less than the angle 1 - the angle between the vertical part of the transfer screen and the perpendicular line to the ellipse tangent drawn to the point of crossing (B) of the retention section of the broken part with the vertical part of the transfer screen, and the retention section length depends on the value a, which characterises the flow mass. The height of the vertical part of the screen to the broken part of the screen (B-D) is selected depending on the angle max, being a characteristic of snow drifting. ^ EFFECT: increased operational reliability. ^ 11 cl, 2 dwg |
