Drilled Shaft Design for Sound Barrier Walls, Signs, and Signals

Details

• Creators:
  Nusairat, Jamal ; Liang, Robert Y. ; Engel, Rick ; Hanneman, Dennis ; Abu-Hejleh, Naser ; Yang, Ke
• Corporate Creators:
  E. L. Robinson Engineering of Ohio Co.
• Corporate Contributors:
  Colorado. Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Lateral supports
  • Torsional strength
  • Walls
  • Drills
  • Load tests
  • Analysis
  • Design capacity
  • Noise barriers
  • Signs
  • Signals
  More +
• Publication/ Report Number:
  CDOT-DTD-R-2004-8
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Colorado
• Edition:
  Final Report, June 2002-June 2004
• Corporate Publisher:
  Colorado. Department of Transportation
• Abstract:
  The Colorado Department of Transportation (CDOT) uses drilled shafts to support the noise barrier walls and the large overhead signs and signals placed alongside the highways. These structures are subjected to predominantly lateral loads from wind. Current CDOT design for the drilled shafts is very conservative and lacks uniformity, which could lead to high construction costs for these shafts. CDOT commissioned a research study with the objective of identifying/developing uniform and improved design methods for these structures. Toward these goals, existing analysis methods for both capacity estimate and load-deflection predictions of drilled shafts supporting sound barrier walls, signs, and signals and typical soil and rock formations in Colorado are presented in a comprehensive manner. This includes the practice of CDOT engineers and consultants for design methods and geotechnical investigation, AASHTO design methods and specifications, and the design practice of the Ohio DOT. The accuracy of selected design methods for lateral and torsional responses of drilled shafts was evaluated by comparing predictions from these methods with measured "true" capacity and deflections from lateral and torsional load tests reported in the literature, performed in Ohio, and two new lateral load tests performed in this study as a part of the CDOT construction project along I-225 where noise barriers walls were constructed. A comprehensive geotechnical investigation program was also carried out at the two new lateral load test sites that included a pressure meter test, Standard Penetration Test (SPT), laboratory triaxial CU tests, and direct shear tests. This allowed for evaluation of the accuracy of various testing methods employed for determining the soil parameters required in the lateral design methods. Finite element modeling have been developed and validated against the new load test data. Additional consideration of possible loading rate effect, cyclic loading effect, and ground water table fluctuations on the soil resistance are discussed. The appropriateness of the recommended factor of safety (FS) for the Broms method was further verified with LRFD calibration.
• Format:
  PDF
• Funding:
  80.19
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93308/dot_93308_DS1.pdf
• File Type:
  [PDF - 12.02 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:95ae0faf3d40c5743b46c03345b6e9e3ef4fa64cd870189eb296123fc8720bf89c04259bdb8ac7feb397dff6a03fbc84d3bceec8657651733619729ee45c9db5