At the start of the year CD Surveys were approached to discuss how we can carry out a monitoring job to assess if the concrete foundations for two portacabin class rooms were moving. Given our extensive experience with monitoring basements for multi-million-pound houses across London, we thought this would be a relatively simple task.
Our first site visit threw somewhat of a spanner in the works as we then realised that to access foundations we had to crawl under the class rooms. This crawl space was large enough to work but only once you gained access through the small entrance. Although technically this space may not be classified as a ‘confined space’ it was certainly an interesting experience to set up the job on my hands and knees placing retro targets on all relevant concrete foundation supports. Small temporary lighting was also required to place around the crawl space to brighten up the area to enable the instruments cross hairs to easily be viewed.
Once the targets were all placed I had to manoeuvre all the additional equipment required so that I could take three sets of readings on each of the targets to formulate the start values to compare each subsequent visit to. As you can see the equipment required for this type of job is slightly more than the average day for a surveyor.
Once this visit was completed and the readings had been processed and ‘meaned’ out to give the site base readings. These results are then used as our comparison for the next visit or visits. The number and frequency of site visits is completely down to the client’s requirements.
1st November 2017
C D Surveys were commissioned to carry out a topographical survey in the Farringdon area of London, the job entailed approximately 200 meters of road…Find out more