Setting Out

Job Information:

We were asked to assist with the setting-out works and maintain detailed records through as-built surveys for a site in Chatteris, Cambridgeshire. The project involved new bridge works to provide vital access to land designated for development. Our team was tasked with ensuring the precise measurement and documentation of the bridge construction, which required a high level of accuracy and attention to detail. This project was for one of our long-standing and valued clients, who has not only been satisfied with the results but has also gone on to recommend us to other contractors in the industry. We truly appreciate their trust and continued support, and it’s always rewarding to see our efforts lead to new opportunities through positive referrals.

Methodology:

During our first visit to the site, we set up a control network based on an old survey with limited control points remaining. Using survey-grade GNSS units, we identified the last two control points and established a baseline for control, despite the challenge of very few permanent features. We placed control on neighbouring roads and structures to maintain consistent reference points as the site evolved.

The initial work involved installing a temporary cofferdam and pumping out water. At this stage, we established level datums and conducted a survey to confirm topographical survey levels, along with volume calculations for bulk fill material. Following this, we cleared the drain to good ground, laid Terram, and added stone in layers. Throughout, we provided datums, recorded levels at each layer, and produced as-built drawings, with the main challenge being the constantly changing site conditions.

In subsequent phases, we set out tensar layers at 300mm intervals and conducted further surveys and setting out. We also set out the sheet piling bridge protection zone, which required a level survey and marking the pile line with pins and caps. After the sheet piles were installed, we set out positions for the continuous filled auger piles for the bridge and then set out the pile cap for reinforcement installation.

Intermediate levels and checks were often carried out by the site agent while we focused on other tasks, such as setting out lean mix. We also performed as-built surveys for the shuttering and checked levels. After the pile caps were poured, we marked any errors and set out service points for re-bar. As the bridge beams were installed, we checked their levels and positions. Simultaneously, we began setting out work for the site area and the entrance leading up to the 278 works.

Currently, we continue to carry out setting out and survey works on the site while also starting a new school project for the same client.