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

摘要

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.