Detecting Pile Length of Sign Structures and High Mast Poles

Principal Investigator(s):

Bojan Guzina, Professor, Civil, Environmental and Geo-Engineering


  • Joseph Labuz, Professor & Department Head, Civil, Environmental and Geo-Engineering

Project summary:

Several hundred high mast light towers (HMLTs) throughout Minnesota have foundation systems, which are typically concrete-filled steel pipe piles or steel H-piles with no construction documentation (e.g. pile lengths) or soil stratigraphy information. Reviews of designs within current standards suggest that many of these foundations could have insufficient uplift capacity in the event of peak wind loads. Without knowledge of the pile length, an expensive retrofit or replacement program would need to be conducted. Thus, providing a screening tool to determine pile length as compared to a bulk retrofit of all towers with unknown foundations would be cost effective. The objective of this project is to establish a field method, including a data analysis algorithm, for determining in-place pile lengths. A unique feature of the proposed work is the use of computational modeling to explore the effects of soil type and ground conditions on the sensitivity of the method. The length of each pile supporting an HMTL is identified through a systematic sensing approach that includes: 1) collection and classification of the pertinent foundation designs and soil conditions; 2) three-dimensional (3D) simulation of dynamic soil-foundation interaction; 3) parametric studies of the 3D pile vibration problem; 4) field testing; and 5) analysis-driven data interpretation.

Project details: