PROCEEDINGS OF A SYMPOSIUM ON DOWNDRAG OF PILES

A SYMPOSIUM ON NEGATIVE SKIN FRICTION (DOWNDRAG) OF PILES WAS HELD TO ACQUAINT PRACTICING CIVIL ENGINEERS WITH THE RESULTS OF A RESEARCH PROJECT CONDUCTED BY THE GEOTECHNICAL DIVISION OF THE CIVIL ENGINEERING DEPARTMENT AT M.I.T. THE RESEARCH WAS SPONSORED BY THE MASSACHUSETTS DEPARTMENT OF PUBLIC WORKS AND THE FEDERAL HIGHWAY ADMINISTRATION. THE BRIDGE CHOSEN FOR THE STUDY HAD ABUTMENTS SUPPORTED ON STEEL PILES (14 BP 73) DRIVEN THROUGH 13 FEET OF SAND AND 50 FEET OF SOFT CLAY TO BEARING IN VERY DENSE GLACIAL TILL. A 25-FOOT HIGH APPROACH FILL PROVIDED THE SURVHARGE. SINCE THE PILES WERE NOT INSTRUMENTED PRIOR TO DRIVING, AN INDIRECT FIELD MEASUREMENT SYSTEM WAS USED TO DETERMINE THE DOWNDRAG LOADING ON ONE PILE IN THE WEST ABUTMENT. PRIOR TO FIELD MEASUREMENTS, SIX ENGINEERS WERE ASKED TO PREDICT PERFORMANCE AND TO SUBMIT THE PREDICTIONS TO PROF. R.B. PECK OF THE UNIVERSITY OF ILLINOIS, WHO ACTED AS REFEREE. A FIELD AND LABORATORY SAMPLING AND TESTING PROGRAM WAS CARRIED OUT TO PROVIDE THE PREDICTORS WITH SOIL PARAMETERS FOR THEIR WORK. PREDICTIONS OF STRUCTURAL AND DOWNDRAG LOADS MADE BEFORE THE FIELD TESTS BY THE SIX ENGINEERS WERE SUBSTANTIALLY DIFFERENT FROM THE MEASURED LOADS, BUT WERE WITHIN REASONABLE ENGINEERING ACCURACY FOR THE BACKFIGURED DOWNDRAG LOADS. PREDICTIONS OF MOVEMENTS, HOWEVER, VARIED WIDELY, SOME AS MUCH AS PLUS MINUS 100% FROM THE MEASURED VALUES. THIS FACT INDICATES THAT THE FUNDAMENTALS CONCERNING DOWNDRAG ARE NOT WELL UNDERSTOOD. IT WAS CLEARLY SHOWN THAT DOWNDRAG DID IN FACT EXIST. MORE RESEARCH IS REQUIRED TO DETERMINE THE FUNDAMENTALS REGARDING THE PREDICTION OF THE EFFECTS OF DOWNDRAG AS WELL AS THE IMPORTANCE OF PILE-STRUCTURE INTERACTION. /NTIS/

• Supplemental Notes:
  • Contract R-21-0
• Corporate Authors:

  Massachusetts Institute of Technology

  Department of Civil Engineering, 77 Massachusetts Avenue
  Cambridge, MA  United States  02139

  Geotech Div

  ,    
• Authors:
  • Garlanger, J E
  • Lambe, T W
• Publication Date: 0

Media Info

• Pagination: 102 p.

Subject/Index Terms

• TRT Terms: Downwash; Field tests; Forecasting; Foundations; Skin resistance; Support piles
• Uncontrolled Terms: Field measurements
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00230789
• Record Type: Publication
• Source Agency: Massachusetts Department of Public Works
• Report/Paper Numbers: Proc
• Files: TRIS
• Created Date: Jun 19 1974 12:00AM