00206550

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http://onlinepubs.trb.org...ubs/hrr/1965/71/71-001.pdf

IN THE U.S.A. THE BEARING CAPACITY OF FLEXIBLE PAVEMENTS IS OFTEN REDUCED DURING THE SPRING THAW, PARTLY BECAUSE BASE AND SUBGRADE MATERIALS HAVE EXPANDED BY FROST HEAVE AND PARTLY BECAUSE THE SOIL HAS BECOME SATURATED AND THERE IS EXCESS OF PORE PRESSURE CAUSED BY RAPID MELTING OF ICE LENSES. IN 1963 THE AUTHOR PROPOSED A DESIGNED METHOD FOR FLEXIBLE PAVEMENTS BASED ON THE ASSUMPTION THAT FAILURE TAKES PLACE IN A FULLY SATURATED SUBGRADE. THE PRESENT PAPER CONCERNS THE EFFECT OF DEGREE OF SATURATION ON BEARING CAPACITY WHICH IS A FUNCTION OF THE APPARENT ANGLE OF INTERNAL FRICTION AND OF THE APPARENT COHESION AS EVALUATED BY UNDRAINED TRIAXIAL OR DIRECT SHEAR TESTS. THE APPARENT FRICTION ANGLE DECREASES RAPIDLY WITH INCREASING PORE PRESSURE COEFFICIENT AND THE APPARENT COHESION INCREASES RAPIDLY WITH INCREASING DEGREE OF SATURATION AND PORE COEFFICIENT. THE EFFECT OF OTHER FACTORS IS SMALL WHEN THE APPARENT COHESION OF THE SOIL EXCEEDS 400 LB/FT2. CALCULATIONS OF THE ULTIMATE BEARING CAPACITY OF FLEXIBLE PAVEMENTS ON SUBGRADES OF /A/ SILT OF LOW COMPRESSIBILITY AND /B/ CLAY OF MEDIUM PLASTICITY FOR DIFFERENT PAVEMENT THICKNESSES, TYRE CONTACT PRESSURES AND SUBGRADE SATURATION SHOW THAT THE DEGREE OF SATURATION GREATLY AFFECTED THE BEARING CAPACITY OF THE PAVEMENT. /RRL/

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01410031

pp 1-14

1965

Highway Research Record

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Figures (15) ; References (17)

Bearing capacity; Clay; Coefficient of internal friction; Cohesion; Compressibility; Design; Direct shear tests; Flexibility; Flexible pavements; Frost; Frost heaving; Pavement design; Percent saturation; Plasticity; Pore pressure; Pressure; Silts; Subgrade (Pavements); Tires; Triaxial shear tests

Contact pressure; Design criteria; Flexible

Design; Highways; Pavements; Vehicles and Equipment

TRIS, TRB

Dec 12 1994 12:00AM

• A CRITICAL REVIEW OF PRESENT KNOWLEDGE OF THE PROBLEM OF RATIONAL THICKNESS DESIGN OF FLEXIBLE PAVEMENTS
• AN INVESTIGATION OF THE DESTRUCTIVE EFFECT OF FLOTATION TIRES ON FLEXIBLE PAVEMENT
• ANALYSIS OF AASHO ROAD TEST ASPHALT PAVEMENT DATA BY THE ASPHALT INSTITUTE
• DESIGN CURVES FOR FLEXIBLE PAVEMENTS BASED ON LAYERED SYSTEM THEORY
• GEORGIA SATELLITE FLEXIBLE PAVEMENT EVALUATION AND ITS APPLICATION TO DESIGN
• LAYERED PAVEMENT DESIGN METHOD FOR MASSACHUSETTS
• LOW MODULUS PAVEMENT ON ELASTIC FOUNDATION
• RESULTS OF OKLAHOMA FLEXIBLE PAVING RESEARCH PROJECT
• SOME NOTES ON PAVEMENT STRUCTURAL DESIGN - PART 2