Determining Pattern of Size and Spacing of Rebar Reinforcements of a “Retention-Wall” Prior to an Overbuild in Bucks County, PA

Project Description:

American Geophysics stated by using both the Profoscope and concrete scanner/GPR. By doing this the field technician was able to determine the rebar size and spacing in both directions of the retention wall in question. Although uncommon, the data collected supported the hypothesis that the horizontal reinforcements of the retention wall were larger than the vertical components. The Profoscope was able to determine that the horizontal bars were #5, and the vertical bars were #4. In the thirty years, both the structural engineer and architect have been working in the field, neither had ever seen a design of a retention wall where the horizontal components were larger than the vertical, so the technician marked out the rebar pattern for a core sample to be collected, proofed and sent to the lab for testing.

Not only was the technician accurate in marking out the detected rebar/reinforcements, but the core sample also “proved” in real-time, that the horizontal bars we indeed the correct size as the equipment and data collected supported; but also proved that the horizontal bars were indeed larger than the vertical bars. Both engineers on-site were in shock, but we trust our data collection process and methodologies. At American Geophysics Inc., we always look for the opportunity to collect as much data as possible, as well as have multiple pieces of equipment confirm the irregularity of this engineering design. No as-builts, reference maps, or drawings were provided or available for this project, and this was purely a fact-finding mission to help the expansion/overbuild or determine if the retention wall was structurally sound; prior to the construction of the new design for the building.

• Products: Proceq Profoscope, GSSI Mini XT 2.7 GHz GPR Concrete Scanner
• Concrete Scanner/GPR
• Concrete Scanning
• Ground Penetrating Radar (GPR)
• Geophysical Services