PLASTIC PIPE OBSERVATION WELLS FOR RECORDING GROUND WATER LEVELS AND DEPTH OF ACTIVE SLIDE MOVEMENTS

FINDING METHODS OF CORRECTING LANDSLIDES OR MAJOR CUT SLOPE FAILURES REQUIRES THAT THE INVESTIGATOR HAVE A DETAILED KNOWLEDGE OF THE SOIL AND WATER CONDITIONS IN THE AREA. BEFORE ANALYSES CAN BE MADE THE ENGINEER MUST KNOW (1) THE GEOMETRY OF THE GROUND SURFACE (CROSS SECTIONS EXTENDING ABOVE AND BELOW THE LANDSLIDE TO FLAT TERRAIN); (2) THE LIMITS OF MOVEMENT AND ANY CONTROLLING INFLUENCES (ROCK OUTCROPS, SPRINGS, STREAMS, UTILITIES, BUILDINGS, ROADWAYS, ETC.); (3) POSITION AND SLOPE OF THE FAILURE PLANE OR ZONE; (4) POSITION AND SLOPE OF THE GROUNDWATER SURFACE; AND (5) CHARACTERISTICS OF THE SOIL IN THE AREA OF THE FAILURE. ITEMS 3, 4, AND 5 ARE DIFFICULT TO OBTAIN, REQUIRING SUBSURFACE EXPLORATION METHODS. THE NEW YORK STATE DEPARTMENT OF TRANSPORTATION IS PRESENTLY COMBINING THESE THREE INVESTIGATIONS IN ONE DRILL HOLE. CONTINUOUS SOIL SAMPLES ARE OBTAINED TO ROCK OR TO A POINT BELOW ANY POSSIBLE FAILURE PLANES. A PERFORATED PLASTIC PIPE OBSERVATION WELL IS THEN INSTALLED IN THE OPEN DRILL HOLE. BY CAREFUL INSTALLATION AND OBSERVATION, THE PLASTIC PIPE OBSERVATION WELL PROVIDES INFORMATION ON THE DEPTH TO GROUNDWATER AND THE DEPTH TO AN ACTIVE FAILURE PLANE. THIS TYPE OF INSTALLATION WAS FIRST DEVELOPED BY THE CALIFORNIA DIVISION OF HIGHWAYS FOR MONITORING EMBANKMENT FOUNDATION SHEAR FAILURES. THE COST OF MATERIALS AND LABOR IS A RELATIVELY MINOR ADDITIONAL COST TO THE STANDARD DRILLING OPERATION. THIS TYPE OF INSTALLATION HAS BEEN FOUND TO BE A VALUABLE CONTRIBUTION TO THE SOLUTION OF STABILITY PROBLEMS INVOLVING ACTIVE SLIDE AREAS. /AUTHOR/

  • Authors:
    • McGuffey, V C
  • Publication Date: 1971-8

Media Info

  • Features: Figures;
  • Pagination: p. 1-3
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00230102
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 29 1972 12:00AM