AUGER AND SLURRY MICROTUNNELING TESTS UNDER CONTROLLED GROUND CONDITIONS

Microtunneling tests using auger and slurry machines were performed at a test facility that was constructed by first excavating a trench 104 m (340 ft) long, 5 m (16 ft) wide, and 3 to 4 m (10 to 13 ft) deep into which six types of soils were placed and compacted in sections approximately 18 m (60 ft) long. The soil profiles included a lean silty clay (loess), a dry sand, highly plastic buckshot clay, wet sand, clay gravel, and silt. The interfaces between soil profiles were sloped to simulate mixed-face conditions and to provide challenges to ground control and alignment and grade control during these transitions. Moisture and density tests were performed to ensure uniformity. Horizontal inclinometers and settlement plates together with surface survey points provided data to evaluate settlement and heave along the test section. Penetration resistance was measured in each section of the completed test bed. Strain gauges were installed in eight of the centrifugally cast, fiberglass-reinforced polyester resin pipes 600 mm (24 in.) in diameter (supplied by Hobas Pipes USA) to measure strains in the pipe as it was being jacked into place. Steering jack loads, jacking thrust loads, and cutterhead torque were also measured during the drives. The results of these tests will be used together with other information to develop guidelines for conducting feasibility studies and selecting proper methods compatible with anticipated ground conditions and project requirements. Preliminary guidance for microtunneling and pipe jacking projects, including the effects of overcut and lubrication on jacking loads and ground deformations, is offered on the basis of test results and related studies.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 75-82
  • Monograph Title: Culvert distress and failure case history and trenchless technology
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00666222
  • Record Type: Publication
  • ISBN: 0309055091
  • Files: TRIS, TRB
  • Created Date: Sep 15 1994 12:00AM