ShaftCam: A Practical and Cost Effective Solution to Drilled/bored Pile Hole Inspection-Paper

Paper

Pdf Summary

The paper presents ShaftCam, a portable digital borescope developed to make drilled-pile bottom inspections safer, faster, and more practical. Sediment left at the base of bored piles—particularly end-bearing piles—can contribute to settlement. Although inspection requirements vary across U.S. jurisdictions, existing methods and devices are often cumbersome, costly, or limited: some provide visual evidence, while others measure sediment thickness without showing the pile bottom.<br /><br />ShaftCam combines both functions. Its 8-inch bell houses a pan-and-tilt camera, adjustable LED lights, an air connection, and a calibrated spring-loaded penetrometer. A clear fiberglass skirt forms an inspection chamber. After the device is lowered to the shaft base, compressed air displaces water, slurry, or polymer so the camera can capture the bottom. The penetrometer measures sediment thickness and resistance, with results displayed and time-stamped by software. The skirt can also be enclosed to inspect shaft walls.<br /><br />The equipment is lightweight, uses a portable air compressor rather than nitrogen, and can be operated by one person. The authors report that setup and inspection of five locations take less than 30 minutes. Field examples show inspections of rock, sand, clay, disintegrated rock, shaft walls, and silty-sand sediments.<br /><br />The paper reports successful use on multiple U.S. projects, where ShaftCam helped contractors and owners implement pile-quality controls more readily. Its combination of visual documentation and measurements is intended to reduce inspection costs and uncertainty, support confidence in foundation construction, and help avoid disputes and additional testing after construction.

Keywords

ShaftCam

borescope

drilled-pile inspection

bored pile

sediment thickness

penetrometer

foundation construction

pile bottom

shaft walls

compressed air