Always Have a Simple Backup
Dr. Peck officiated a Symposium Downdrag on Piles at MIT in the early 1970s. I was helping a fellow graduate research assistant, Sam, with his research project. An excavation was made below an abandoned pile-supported bridge abutment known to have downdrag on the steel H-piles. We cut a 2-in. section from one pile and measured the rebound under several scenarios. Professionals in the field made predictions on the movement under the scenarios and presented their predictions at the symposium. Dr. Peck observed the pile response and validated the movement. We installed three systems to measure pile movement - dial gauges, a Vernier caliper and an engineer's level. We took our initial readings, and as I prepared to cut the 2-in. section from the pile, Dr. Peck reviewed our measurement systems and then placed a pencil mark above and below the section to be cut and recorded the distance between pencil marks.
Always the practical engineer, he commented that you should have a simple backup means to verify filed measurements.
Kenneth L. Recker, P.E
This letter is an excerpt from the Geo-Strata Feature on Professor Peck, Geo-Strata September/October 2008.