SLOPE AND ROUNDING DESIGN
THIS STUDY WAS MADE TO DETERMINE THE CRITICAL SLOPE RATIOS AND THE MINIMUM ROUNDINGS REQUIRED FOR ECONOMICAL OPERATION OF TYPICAL MOWING EQUIPMENT PRESENTLY AVAILABLE. CONSIDERING THE LARGE ACREAGES OF ROADSIDES CHARACTERISTC OF HIGHWAYS SUCH AS THE INTERSTATE SYSTEM, AN EXTRA PASS OF A MOWER COULD ADD SIGNIFICANTLY TO THE MOWING TIME AND EFFORT REQUIRED. IT WAS ASSUMED FOR THE PURPOSE OF THIS STUDY THAT THE CROSS-SECTION WHERE MOWING TIME WAS TO BE EXPECTED SHOULD NOT PRESENT A GROUND FORM WHICH WOULD LIMIT THE OPERATION OF MOWING EQUIPMENT. FOR EXAMPLE, IT WAS ASSUMED THAT IT MIGHT BE DESIRABLE TO OPERATE EQUIPMENT WITH THE CENTER OF THE MOWER OVER THE LOW POINT OF THE DRAINAGE CHANNEL. THIS SEEMED REASONABLE TO PREVENT THE POSSIBILITY OF AN EXTRA PASS OF THE MOWER WHICH MIGHT BE NECESSITATED BY A V-SHAPED DRAINAGE CHANNEL MOWED BY A SEPARATE PASS ON EACH SIDE OF ITS CENTER. FOUR MOWER SIZES WERE CONSIDERED IN THIS STUDY. THE GANG-TYPE REEL MOWER HAD INDIVIDUAL UNITS WITH A SPAN OF 41 1/2 IN. BETWEEN CENTERS OF WHEELS. THE ROTARY AND THE HAMMER KNIFE MOWERS HAD 48-, 60-, AND 72-IN. SPANS BETWEEN WHEELS. THE SICKLE-BAR MOWER WAS NOT CONSIDERED BECAUSE OF ITS SLOW SPEED OF TRAVEL. OPERATION ON SLOPES FLATTER THAN 3:1 WAS SATISFACTORY. THIS PERFORMANCE MIGHT VARY WITH SEVERAL FACTORS SUCH AS THE MODEL OF EQUIPMENT, THE TYPE AND CONDITION OF VEGETATIVE COVER, THE KIND OF SOIL AND THE MOISTURE CONDITIONS. ALTHOUGH IT IS POSSIBLE TO MOW 2:1 SLOPES OR STEEPER BY RUNNING THE MOWER DOWN THE SLOPE CROSSING THE CONTOURS, THIS IS A TIME CONSUMING OPERATION AND IS NOT TO BE CONSIDERED BY THE PREMISE THAT GROUND FORMS SHOULD NOT LIMIT THE USE OF MOWING EQUIPMENT. A CURVE WAS DEVELOPED FOR EACH OF THE CONDITIONS BY COMPUTATION AND GRAPHICALLY, AND THE RADIUS OF CURVE AND THE PROJECTED HORIZONTAL DISTANCE THAT EACH CURVE COVERED WAS DETERMINED. THE CURVES DEVELOPED CONFORMED CLOSELY TO PARABOLIC CURVE. /AUTHOR/
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Supplemental Notes:
- No 774, pp 4-8, 4 FIG, 1 TAB. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
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Corporate Authors:
Reports
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Authors:
- Iurka, H H
- Tetelman, B
- Publication Date: 1960
Media Info
- Media Type: Digital/other
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Serial:
- Highway Research Board Roadside Development Committee Reports
- Publisher: Highway Research Board
Subject/Index Terms
Filing Info
- Accession Number: 00205157
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Nov 29 1971 12:00AM