00233095

Component

https://onlinepubs.trb.or...bproceedings/26/26-042.pdf

AN INVESTIGATION OF THE LOAD-CARRYING CAPACITY OF NATURAL SUBSOILS AND BASE-SUBGRADE COMBINATIONS IS REPORTED. THE VARIABLES INVESTIGATED INCLUDED: (1) SOIL TYPE, (2) TYPE OF GRANULAR-BASE MATERIAL, (3) DEPTH OF BASE MATERIAL, AND (4) SEASONAL MOISTURE. LOADING TESTS WERE PERFORMED ON TEST SECTIONS LOCATED ON EACH OF THREE SUBGRADE SOILS (WARSAW, CROSBY, AND BROOKSTON) BOTH NATURAL AND REINFORCED WITH THREE DEPTHS (6-, 12-, AND 18-IN) OF EACH OF THREE BASE MATERIALS (PIT-RUN GRAVEL, CLAY-GRAVEL, AND CRUSHED LIMESTONE). THE INFLUENCE OF SEASONAL MOISTURE CHANGES WAS STUDIED BY LOADING THE TEST SECTIONS AT TWO SEASONAL MOISTURE PERIODS; ONCE DURING THE DRY SEASON AND AGAIN DURING THE WET SPRING SEASON. SIXTY LOADING TESTS WERE INCLUDED IN THE PRINCIPAL PART OF THE TESTING PROGRAM. ONE OF THE RESULTS OF THIS INVESTIGATION WAS THE DEVELOPMENT OF A CYCLE-LOADING PROCEDURE WITH WHICH NOT ONLY THE BEARING VALUES OF BASE-SUBGRADE COMBINATIONS CAN BE MEASURED, BUT ALSO THE ELASTIC AND PERMANENT DEFLECTION CHARACTERISTICS OF BOTH THE BASE AND SUBGRADE CAN BE DETERMINED. ALTHOUGH THE INVESTIGATION DOES NOT DEAL DIRECTLY WITH PAVEMENT DESIGN, THIS TEST METHOD HAS PERMITTED AN ACCUMULATION OF DATA PERTINENT TO AN UNDERSTANDING OF THE FACTORS CONTROLLING DESIGN. IT WAS FOUND THAT THE THREE SUBGRADE SOIL TYPES SELECTED FOR THIS INVESTIGATION HAD A WIDE RANGE IN LOAD- CARRYING CAPACITY WHICH VARIED IN ACCORDANCE WITH THEIR ENGINEERING SOIL-PROFILE CHARACTERISTICS. THE SUBGRADE SOIL WHICH HAD THE LEAST BEARING-CAPACITY ALSO HAD THE GREATEST CAPACITY FOR DEFLECTION-RECOVERY. CONVERSELY, THE SUBGRADE SOIL WHICH HAD THE GREATEST BEARING CAPACITY HAD THE LEAST CAPACITY FOR DEFLECTION-RECOVERY. THESE DIFFERENCES IN THE ABILITY OF SUBGRADE SOIL TO RECOVER DEFLECTION INDICATE THE NEED FOR ADDITIONAL RESEARCH TO CORRELATE THIS CHARACTERISTICS WITH DESIGN AND CONSTRUCTION PROCEDURE. WITH REGARD TO THE LOAD-CARRYING CAPACITY OF BASE-SUBGRADE COMBINATIONS, IT WAS FOUND THAT FOR LARGE VALUES OF PLATE DIAMETER-BASE DEPTH RATIO THE BEARING CAPACITY DEPENDS PRIMARILY UPON THE CHARACTERISTICS OF THE SUBGRADE SOIL; FOR DECREASING VALUES OF PLATE DIAMETER-BASE DEPTH RATIO THE BEARING CAPACITY OF THE COMBINATION BECOMES INCREASINGLY DEPENDENT UPON THE STABILITY OF THE BASE MATERIAL. THE RESULTS INDICATE THAT THE DENSITY AND THE GRADING CHARACTERISTICS OF THE BASE MATERIALS ARE THE MAJOR FACTORS WHICH INFLUENCE BASE STABILITY. /AUTHOR/

Vol 26, pp 521-543, 10 FIG, 8 TAB, 33 REF, APP. 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.

01490427

1947 (approximate)

Highway Research Board Proceedings

Digital/other

Base course (Pavements); Density; Granular materials; Load tests; Moisture content; Seasons; Soils; Subgrade (Pavements)

Seasonal variations

Geotechnology; Highways

TRIS, TRB

May 22 1972 12:00AM

• A COMPARATIVE STUDY OF DATA FROM THE COOPERATIVE INVESTIGATION OF JOINT SPACING
• A METHOD OF COMPUTING LIVE LOADS TRANSMITTED TO UNDERGROUND CONDUITS
• A STUDY OF LATERITIC SOILS
• ABUTMENTS FOR SMALL HIGHWAY BRIDGES - PART 4
• ACCELERATED TRAFFIC TESTS FOR FLEXIBLE AIRFIELD PAVEMENTS
• ANALYSIS OF LOADS AND SUPPORTING STRENGTHS AND PRINCIPLES OF DESIGN FOR HIGHWAY CULVERTS
• APPLICATION OF STATISTICAL SAMPLING METHODS TO TRAFFIC PERFORMANCE AT URBAN INTERSECTIONS
• APPLICATION OF TRIAXIAL COMPRESSION TEST RESULTS TO THE CALCULATION OF FLEXIBLE PAVEMENT THICKNESS
• APPLICATIONS OF THE MOHR CIRCLE AND STRESS TRIANGLE DIAGRAMS TO TEST DATA TAKEN WITH THE HVEEM STABILOMETER
• CAPILLARITY TESTS BY CAPILLARIMETER AND BY SOIL FILLED TUBES
• COMPACTION AND STRENGTH CHARACTERISTICS OF SOIL AGGREGATE MIXTURES
• COOPERATIVE PROGRAMS OF THE UNITED STATES GEOLOGICAL SURVEY WITH HIGHWAY DEPARTMENTS
• CURRENT BASE DESIGN PRACTICES IN NORTH CAROLINA
• DESIGN OF FLEXIBLE SURFACES IN MICHIGAN
• DEVELOPMENT OF A PROCEDURE FOR THE DESIGN OF FLEXIBLE BASES
• DEVELOPMENT OF DRAINAGE MAPS FROM AERIAL PHOTOGRAPHS
• EFFECT OF EXPERIMENTAL SUBGRADE TREATMENTS ON PAVEMENT FAULTING AND PUMPING
• HIGHWAY LOCATION AS A SITE PLANNING PROBLEM
• HYDRAULICS OF RUNOFF FROM DEVELOPED SURFACES
• INFLUENCE OF INITIAL MOISTURE AND DENSITY ON THE VOLUME CHANGE AND STRENGTH CHARACTERISTICS OF TWO TYPICAL ILLINOIS SOILS
• MAPCRACKING IN CONCRETE PAVEMENTS AS INFLUENCED BY SOIL TEXTURES
• METHOD FOR RECORDING LATERAL POSITION OF VEHICLES
• MILWAUKEE METHODS OF DETERMINING AND CONTROLLING LENGTHS OF BLOCKS AND INTERSECTIONS
• NEW GLACIAL FEATURES IDENTIFIED BY AIRPHOTOS IN SOIL MAPPING PROGRAM
• ON THE HYDROLOGY OF CULVERTS
• ORIGIN AND DESTINATION SURVEY METHODS AS APPLIED TO THE TRANSPORTATION STUDY-BALTIMORE METROPOLITAN AREA
• PAVEMENT PERFORMANCE SURVEYS
• PROGRESS REPORT ON DEVELOPMENT AND USE OF STRENGTH TESTS FOR SUBGRADE SOILS AND FLEXIBLE BASE MATERIALS
• PROVIDENCE CENTRAL BUSINESS DISTRICT PARKING SURVEY
• PURPOSE, ANALYSIS AND APPLICATION, ORIGIN AND DESTINATION SURVEY, MILWAUKEE METROPOLITAN AREA
• REPORT OF COMMITTEE ON ROADSIDE DEVELOPMENT
• REPORT OF PROJECT COMMITTEE ON PARKING
• SEVEN YEARS' PERFORMANCE OF A BITUMINOUS SURFACE TREATMENT TEST ROAD
• SOME CRITERIA FOR SCHEDULING MECHANICAL TRAFFIC COUNTS
• SOME EXPERIMENTS ON CAPILLARY FLOW OF MOISTURE THROUGH GRAVELS AND SILTS
• SOME MEASUREMENTS OF VELOCITIES AND SCOUR AT A MISSISSIPPI RIVER BRIDGE PIER
• SOME OBSERVATIONS ON RESURFACING PORTLAND CEMENT CONCRETE PAVEMENTS WITH BITUMINOUS MIXTURES
• STABILIZED SHOULDERS WHICH WILL SUPPORT VEGETATION
• STATE GENERAL, SPECIAL AND LOCAL ENABLING LEGISLATION DEALING WITH AUTOMOBILE PARKING FACILITIES
• THE APPLICATION OF AERIAL STRIP PHOTOGRAPHY TO HIGHWAY AND AIRPORT ENGINEERING
• THE COOPERATIVE PROJECT ON STRUCTURAL DESIGN OF NONRIGID PAVEMENTS
• THE EVALUATION OF WHEEL LOAD BEARING CAPACITIES OF FLEXIBLE TYPES OF PAVEMENT
• THE ROLE OF CALCIUM CHLORIDE IN COMPACTION OF SOME GRANULAR SOILS
• THE USE OF THE AMERICAN TRANSIT MOTOR ABILITY TEST IN THE SELECTION OF BUS AND STREET CAR OPERATORS
• TOLL BRIDGES INFLUENCE ON HIGHWAY TRAFFIC OPERATION
• USE OF STREAM-FLOW RECORDS IN DESIGN OF BRIDGE WATERWAYS
• VIBRATORY AND SLOW REPETITIONAL LOADING OF SOILS