Surrounding earth remains undisturbed, no temporary shoring is needed, and in-place building members remain unstripped as a pile drilling and pouring system underpins existing structures while tunneling and other major digging proceed nearby. The system's rotary steel casings sank deep holes for concrete piles to support a building adjacent to subway construction in Washington, D.C. Five-inch-ID steel casings were drilled 61-1/2 ft. down from ground level. At about 46 to 49 ft. deep, casing cutter heads with tungsten carbide teeth bored through the buildings 3 to 4 ft. thick concrete spread footings. The holing-through permitted the piles to be poured through the foundation. A direct connection was thus created, and the completed concrete piles became an integral part of the structure working as close as 3 in. to the building line, with timber-lagged soldier piles to its rear, the casings were rotated into place with its own 35-hp electric rig. When drilling ended, a 2-in. pipe tremied concrete to the bottom of the casing; reinforcing steel was thrust in and a screwed-on sealing head capped the casing. The jarring action rammed the concrete against the earth - creating an effective bond and eliminating voids.

  • Corporate Authors:

    McGraw-Hill, Incorporated

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

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00127485
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 10 1976 12:00AM