EXPANSIVE SOILS AND CALIFORNIA HIGHWAYS (RESEARCH FINDINGS)

THIS RESEARCH WAS PROMPTED BY SEVERAL SPECIFIC LOCATIONS IN CALIFORNIA OF DISTRESS IDENTIFIED AS BEING CAUSED BY EXPANSIVE SOILS. IN PARTICULAR, THE DRAMATIC EMERGENCE OF SEVERE LOCALIZED CRACKING AND JOINT SEPARATION ON PORTIONS OF NEWLY CONSTRUCTED ROADS THROUGH THE SACRAMENTO VALLEY SERVED AS IMPETUS TO INVESTIGATE THE PROBLEM. THE OBJECTIVES OF THE RESEARCH WERE: (1) TO DEFINE THE EXTENT OF THE PROBLEM; (2) EVALUATE THE EFFECTIVENESS (AND SHORTCOMINGS) OF PRESENT PROCEDURES; AND (3) FID IMPROVED MEANS (EMPIRACAL OR RATIONAL) OF IDENTIFYING SOILS WITH DISTRESS CAUSING POTENTIAL. IN FORMULATING AN APPROACH FOR THE EXPANSIVE SOIL PROBLEM AND CALIFORNIA HIGHWAYS, THE RESEARCH WORK PLAN WAS DIVIDED INTO TOW GENERAL PHASES. THE FIRST PHASE WAS INTENDED TO DEFINE THE PROBLEM FURTHER. FIRST, AN INVENTORY OF LOCATIONS OF EXPANSIVE SOIL TYPE PAVEMENT DISTRESS WAS OBTAINED. FROM THOSE, A LARGE REPRESENTATIVE SAMPLE (50-100) WAS SELECTED FOR A FIELD SURVEY OF PAVEMENT CONDITION AT THESE SITES. ALSO, THE RIDING CONDITION OF THE ROADWAY IN THE VICINITY OF THE REPORTED DISTRESS WAS EVALUATED USING A PCA ROADMETER. THE OBJECTIVE WAS TO DETERMINE, IF POSSIBLE, THE EFFECT OF THE EXPANSIVE SOILS ON RIDING QUALITY OF THE ROADWAY. CONCURRENTLY, THE PROJECT RECORDS (AND OTHER PUBLICLY AVAILABLE DATA) WERE EVALUATED TO SEE IF INFORMATION WHICH COULD BE UTILIZED TO MINIMIZE OR PREVENT THE PROBLEM WAS BEING OVERLOOKED OR NOT UTILIZED TO THE BEST ADVANTAGE. THE SECOND OR ANALYTICAL PHASE INVOLVED AN INTENSIVE ANALYSIS OF APPROXIMATELY 25 LOCATIONS SELECTED FROM THE INITIAL FIELD SURVEY. THOSE WERE REPRESENTATIVE OF THE RANGE OF DISTRESS OBSERVED, AS WELL AS GEOGRAPHICALLY DISTRIBUTED. THIS PORTION OF THE INVESTIGATION INCLUDED TAKING SOIL SAMPLES THROUGH THE ROADWAY, AND AN INTENSIVE "SHOTGUN" PROGRAM OF LABORATORY TESTING. THE DATA WERE ANALYZED TO DETERMINE THE RELATIONSHIP, IF ANY, BETWEEN THESE FACTORS AND THE OBSERVED DISTRESS. THE FOLLOWING CONCLUSIONS WERE REACHED: (1) EXPANSIVE SOIL TYPE DISTRESS IN CALIFORNIA IS PREVALENT ENOUGH TO BE CLASSED AS A SIGNIFICANT PROBLEM. (2) THE PROBLEM IS HIGHLY LOCALIZED. POTENTIAL PROBLEM SITES ARE APT TO BE MISSED BY "RANDOM SAMPLING" TYPE FOUNDATION INVESTIGATIONS, AS CONDUCTED FOR ROUTEINE STRUCTURAL DESIGN PURPOSES. (3) SOILS HAVING MORE THAN 40 PERCENT PASSING THE NO. 200 SIEVE, OR MORE THAN 10 PERCENT OF CLAY SIZED FRACTION (LESS THAN 1.0 MICRON) HAVE A HIGH POTENTIAL FOR CAUSING DISTRESS. OTHER PARAMETERS HAVING USEFUL ASSOCIATIONS ARE CLAY MINERAL IDENTIFICATION, ATTERBERG LIMITS, LINEAR EXPANSION AND SHRINKAGE, AND INTERNAL SURFACE AREA. (4) THE U.S. DEPARTMENT OF AGRICULTURAL SOILS BULLETINS SHOULD BE RESEARCHED WHEN EVALUATING A ROADWAY LOCATION FOR EXPANSIVE SOILS.

  • Supplemental Notes:
    • Proceedings, Workshop on Expansive Clays and Shales in Highway Design and Construction, Denver, Colorado, 1972. Available in 2 volumes from NTIS, PB-225842.
  • Corporate Authors:

    University of Wyoming, Laramie

    Wyoming Survey and Analysis Center, 710 Garfield
    Laramie, WY  USA  82070
  • Authors:
    • Smith, R E
  • Publication Date: 1973-5

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Filing Info

  • Accession Number: 00233457
  • Record Type: Publication
  • Report/Paper Numbers: Workshop Proceedings
  • Files: TRIS
  • Created Date: Jul 31 1974 12:00AM