FOUNDATION WORK: AN UNCERTAIN SCIENCE

Capsulized examples are presented of foundation work ingenuity in this country and overseas during the past 3 years. Electronic caisson alignment to plumb tolerances of 1.3 percent of caisson length helped meet complex specs in a New York harbor project. A gyroinclinometer lowered into a caisson above, measured to within 0.1 deg. and transmitted a reading every 10 ft. during descent. An accompanying TV camera panned 360 deg. checking welding splices and rock/caisson junctures. Unstqble coastal fill and a mud-silt foundation beneath a four-story Hiroshima warehouse were compensated for with adjustable anchor bolts joining frame and foundation. Extra depth (200 ft.) for caisson supports for a 24 story Cleveland building became possible with a 30-ton kelly bar with two 105-ft. elements, one inside the other, and a system of varying auger diameters and protective casings. Supports for a 34-story Toronto office tower had to work around a twin-tube subway tunnel only 20 ft. below the buildings basement level; a series of heavy girders supported on large diameter caissons driven to bedrock straddling the tunnel were the answer. Hydraulically operated drilling machines could drive and socket up to 42-in. steel casings into the bedrock while simultaneously mucking up the shaft. Fast concreting follow-yp of caisson drilling for a 62-story Los Angeles building counteracted deteriorating soil conditions. A floating reinforced cellular Cofferdam was used as a work platform for driving pyramidally patterned sheet piles into an offshore bed as a permanent cut-off wall along a port dock in Mozamabique. A flexible tie back system employing 50 separate units and consisting of multi-strand prestressed cables, replaced rods of comparable strength on a perimeter bulkhead for a deep foundation on the West Coast. A composite pile with an oversized tapered tip displaced soil and then compacted it to a denser base on a New York housing project. A self-jacking barge, working in Chesapeake Bay, sped pile-driving, using a lifting arrangement five times faster than conventional jacks.

  • Corporate Authors:

    McGraw-Hill, Incorporated

    330 West 42nd Street
    New York, NY  USA  10036
  • Publication Date: 1975-8

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Filing Info

  • Accession Number: 00127481
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 10 1976 12:00AM