HIGHWAY DESIGN AND CONSTRUCTION PROBLEMS ASSOCIATED WITH THE LOESSIAL SOILS OF WEST TENNESSEE

THE INTERSTATE HIGHWAY PROGRAM CAUSED TENNESSEE TO BECOME CONCERNED ABOUT THE DESIGN AND CONSTRUCTION OF ROADWAYS IN THE LOESS BELT. THE MOISTURE ACCUMULATION IN THE SUBGRADE IS A PRIMARY FACTOR AFFECTING THE STABILITY OF ROADWAYS CONSTRUCTED IN THE LOESS BELT. SUBGRADE TREATMENT WAS 6 OR 7 PERCENT (BY WEIGHT) PORTLAND CEMENT, AS WELL AS THE PORTLAND CEMENT STABILIZED BASE RECOMMENDED FOR FLEXIBLE PAVEMENTS IN THIS AREA. IF RIGID PAVEMENTS ARE DESIRED, A SOIL-CEMENT BASE IS RECOMMENDED. RIGID PAVEMENTS GENERALLY ARE MUCH MORE SATISFACTORY THAN FLEXIBLE PAVEMENTS WHERE THE DESIGN IS BASED ON COMPARABLE LOAD REQUIREMENTS. THE IMPORTANCE IS RECOGNIZED OF A APPROPRIATE BASE AND PAVEMENT THICKNESSES AND PROPER DRAINAGE. RIGID CONTROLS MUST BE EXERCISED IN THE CONSTRUCTION OF LOESS EMBANKMENTS. PERMEABILITY AND CBR TESTS HAVE PROVEN THAT LOESS, WHEN COMPACTED TO ITS MAXIMUM DENSITY AT OPTIMUM MOISTURE CONTENT, IS ESSENTIALLY IMPERVIOUS. SIDE SLOPES FOR FILLS ARE PRESENTLY CONSTRUCTED ON A 2:1 RATIO. WHATEVER THE SLOPE DESIGN CHOSEN, SURFACE DRAINAGE MUST BE CONTROLLED AT ALL TIMES. SIDE DITCHES SHOULD BE FLAT-BOTTOMED AND, DEPENDING ON THE GRADIENT, SHOULD BE PAVED, SODDED OR SEEDED.

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  • Accession Number: 00237471
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jun 18 1994 12:00AM