STEEL PILINGS IN SOILS

THE PURPOSE IS TO PROVIDE MORE ACCURATE ESTIMATES OF THE USEFUL LIFE OF PILINGS. DATA WERE OBTAINED FROM INSPECTION OF STEEL PIPE, STEEL H-, AND STEEL SHEET-PILINGS THAT HAD BEEN EXPOSED UNDERGROUND FROM 6 TO 50 YEARS IN VARIOUS LOCATIONS. THE SOILS IN WHICH THE PILINGS WERE EXPOSED DIFFERED IN BOTH THEIR PHYSICAL AND CHEMICAL PROPERTIES. SOIL TEXTURE VARIED FROM POROUS SANDS TO IMPREVIOUS CLAYS TO PERMAFROST. SOIL RESISTIVITY RANGED FROM 78 OHM-CM (INDICATING THE PRESENCE OF LARGE QUANTITIES OF SOLUBLE SALTS, NORMALLY CORROSIVE UNDER DISTURBED SOIL CONDITIONS) TO OVER 45,000 OHM-CM (INDICATING ABSENCE OF SOLUBLE SALTS). THE PH OF THE SOILS RANGED FROM 4.1 TO 8.8. THREE METHODS WERE USED FOR INSTALLING PILES: DRIVING, DRY AUGERING, AND STEAM THAWING IN PERMAFROST SOILS. DRIVEN PILES REMAIN STURDY. BUT, FOR THE DRY AUGERING PROCESS, BACKFILLING WAS NECESSARY WITH MATERIAL FROM RIPRAP, CINDERS, SLAG TO COMBINATIONS OF SAND, SILT, LOAM, AND CLAY. WITH STEAM THAWING, PILES WERE INSTALLED DIRECTLY IN THE SILT-WATER SLURRY FORMED DURING THAWING AND NEEDED LITTLE OR NO BACKFILL. NINE STEEL SPECIMENS WERE INSTALLED IN ALASKAN SOILS COMPOSED OF A LAYER THAT THAWS AND FREEZES ANNUALLY AND A PERMANENTLY FROZEN (PERMAFROST) LAYER BENEATH THE THAW LAYER. THE PILE LIFETIMES DO NOT APPEAR TO BE AFFECTED BY CORROSION. NO SIGNIFICANT CORROSION WAS EVIDENT AT ANY SOIL LAYER. ON SITE INSPECTIONS WERE MADE OF PILINGS IN 17 FLOODWALL AND DAM FOUNDATIONS, SOIL SAMPLES AND CORROSION- PRODUCT SCRAPPINGS WERE TAKEN FROM EXPOSED PORTIONS OF THE PILINGS AND EXAMINED IN THE LAB. INSPECTIONS OF 26 STEEL PILES SHOWED THAT CORROSION WAS GENERALLY CONFINED TO ABOVE GROUND PORTIONS OF THE SPECIMENS. A PROBABLY EXPLANATION BEING THAT A GALVANIC CORROSION CELL IS FORMED BETWEEN THE UPPER AND LOWER PORTIONS, WITH THE UPPER PILE PORTION (A SMALL PART OF THE ENTIRE PILE LENGTH BEING CATHODIC TO THE LARGER PORTION OF THE PILE DRIVEN INTO THE SOIL. SO THE AMOUNT OF METAL SACRIFICED BY THE ANODE IN PROTECTING THE SMALL CATHODE IS NEGLIGIBLE. THIS HYPOTHESIS WAS TESTED IN 1966 WHERE PILES WERE INSTALLED IN MONTREAL, QUEBEC AND FUTURE DATA WILL PROVE VALUABLE IN THESE INVESTIGATIONS.

• Supplemental Notes:
  • Vol 55, No 5, PP 120, 3 REF
• Corporate Authors:

  National Bureau of Standards

  Department of Commerce, Office of Technical Publications
  Washington, DC  United States  20234
• Publication Date: 1971-5

Media Info

• Serial:
  • Dimensions NBS

Subject/Index Terms

• TRT Terms: Augers; Corrosion; Electrical resistivity; Installation; Methodology; Performance tests; Permafrost; pH value; Pile driving; Soils; Steam; Steel; Support piles; Texture; Thaw
• Old TRIS Terms: Dry augering; Layered system mechanics; Life testing; Resistivity; Soil texture
• Subject Areas: Geotechnology; Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 00217135
• Record Type: Publication
• Source Agency: National Bureau of Standards
• Files: TRIS
• Created Date: Aug 15 1971 12:00AM