THE SEPERATE ROLES OF SITE INVESTIGATION QUANTIFICATION OF SOIL PROPERTIES, AND SELECTION OF OPERATIONAL ENVIRONMENT IN THE DETERMINATION OF FOUNDATION DESIGN ON EXPANSIVE SOILS

MUCH OF THE CONFUSION THAT HAS ARISEN IN ATTEMPTS TO DETERMINE AN ACCEPTABLE METHODOLOGY FOR FOUNDATION DESIGN ON EXPANSIVE SOILS IS DUE TO THE FACT THAT THERE IS AN INTERACTION BETWEEN SEVERAL ASPECTS OF INVESTIGATION, EACH OF WHICH SHOULD BE CONSIDERED QUITE SEPARATELY. THESE SEPARATE ASPECTS ARE: (1) THE DETERMINATION OF THE TRUE ORIGINAL ENVIRONMENTAL CONDITIONS AT THE SITE PROPOSED FOR THE ERECTION OF THE BUILDING; (2) THE PRECISE DETERMINATION, USUALLY IN THE LABORATORY, OF THE PROPERTIES OF EXPANSIVE SOILS EXPRESSED IN A SUITABLE QUANTITATIVE FASHION, SO THAT THE VARIABLES OF SOIL SUCTION AND OF APPLIED LOAD MAY BE SEPARATELY CONSIDERED; AND (3) THE SELECTION OF THOSE CONDITIONS OF ENVIRONMENT FOR THE OPERATION OF THE BUILDING WHICH ARE PERTINENT TO THE SPECIFIC CIRCUMSTANCES WHICH MAY SURROUND THE SPECIFIC BUILDING. A FAMILY OF CURVES, WITH DIFFERENT INITIAL SUCTION CONDITIONS, MAY BE DEFINED IN THE LABORATORY SO THAT PREDICTIONS MAY BE MADE FROM THE INITIAL SUCTION CONDITION TO ANY SELECTED FINAL SUCTION CONDITION, AND FROM THE INITIAL CONDITIONS OF LOADING IN THE SOIL TO ANY FINAL SELECTED LOADING CONDITIONS. THE COMBINED EFFECT OF CHANGE OF LOAD AND CHANGE OF SUCTION MAY ALSO BE PREDICTED WITH REASONABLE EXPECTATION OF ACCURACY. ONCE THE OPERATIONAL ENVIRONMENTAL CONDITIONS HAVE BEEN ESTABLISHED, IT IS A RELATIVELY EASY TASK TO COMPARE THE CHANGE BETWEEN THE INITIAL AND OPERATIONAL ENVIRONMENT AND TO PREDICT, FROM THE LABORATORY DATA, THE VOLUME CHANGES WHICH WILL OCCUR THROUGHOUT THE WHOLE OF THE SOIL PROFILE. THIS, OF COURSE, LEADS TO THE SELECTION OF FOUNDATION LOADS AND FOUNDATION DEPTHS NECESSARY TO MEET ANY SPECIFICATION OF STRESS-STRAIN ALLOWABLE WITHIN THE SUPERIMPOSED BUILDING. /A/RRL/

Media Info

  • Serial:
    • Issue Number: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00229313
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Jul 6 1970 12:00AM