CASE STUDIES

Rebar Location at Farringdon West

It’s like the Minesweeper Challenge! It is often assumed that concrete reinforcement (rebar) is associated with a ground slab. But, of course, it runs through so many buildings. With an ever-increasing number of tall buildings erected and refurbished in London, the question is…where is the rebar?

First visit:

SUMO asked to survey the Farringdon West site to locate rebar for BAM, Ferrovial & Kier (BFK). BFK was a joint venture set up to accommodate the large Cross Rail Project.

The survey took 3 days on site, collecting Ground Penetrating Radar (GPR) data for post-processing in the search for rebar and pile caps. The survey was a success as the rebar was located, and a high quality deliverable was given to the client.

Alongside the rebar locations, SUMO APR completed modelling survey work. This was among other Measured Building surveys completed on the same site area.

SUMO Geophysics located the rebar at the Farringdon West site.

Ground Penetrating Radar (GPR) and palm antenna used to locate the rebar.

Ground Penetrating Radar (GPR) equipment.

Second visit:

At a later date, we were contacted by HB Reavis to undertake further survey at Farringdon West. This was due to further development that had occurred on the site since the initial survey. The site had been switched over from Cross Rail to HB Reavis.

On this second site visit, we scanned from the 3rd floor into the concrete exterior walls to mark out the rebar using GPR equipment. This was because the new client had plans to drill in a secure platform, in order to position a crane.

To locate the rebar, our surveyor was lifted by crane, in a crane bucket and positioned against the wall. It was then possible to use the GPR equipment to locate and mark-out the rebar. We did this by moving 1 meter at a time until the required areas were complete.