BIM for Coastal Defences: Operational and maintenance data

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This is the third in a series of interviews with Carl Green, Head of Engineering Services for Wyre Council as we follow the progress throughout the construction and operation of the Fylde Peninsula Coastal Programme…

The Fylde Peninsula Coastal Programme (FPCP) is a partnership between Wyre Council, Blackpool Council, Fylde Council and the Environment Agency. It is responsible for managing the Fylde Peninsula’s coastline and reducing risk of flooding to people and the developed, historic and natural environment. The new defences will protect 12,000 properties in total – 7500 in Rossall and 4500 in Anchorsholme plus critical drainage and transport infrastructure

Construction work at Rossall, which is part of the scheme, has been progressing at a significant pace. There is now 500 meters of rock and material which has been placed on the seaward side of the sheet piles. To give this some context, the total weight of the material placed on the beach over this relatively short distance is well over 165,000 tonnes. Carl Green explains the challenges that have arisen to date and how they have been overcome.

“It seems obvious, but one of the key challenges of maintaining the coastal defences is ensuring that they don’t get washed away. Coastal defences, like any asset that comes into contact with water, has to have a drainage solution to allow water to run away. Part of our solution includes specially designed holes and a drainage system that allows water to drain through the sheet piles, whilst retaining the fill behind.

“We were concerned that we would lose a significant amount of fill through these drain holes and suggested a composite geotextile drainage system to be placed in front of the holes. This acts as a filter holding back the solids whilst allowing the water to escape. From a risk management and maintenance point of view, it is vital that we know where these drain holes are, as we will only know that the drainage system has failed when the fill level starts to drop and cracks appear in the defence.”

In order to accurately record this information, they used the Sitedesk ( www.sitedeskconstruct.com ) inbuilt form creator to create a site diary. The form creator allows custom fields to be created as well as photos, videos, PDFs or any content to be embedded into the form itself.

The site diary allows the council officers to record any information that is needed to manage the coastal defences. Green explained;

“In this case, we recorded exactly where the drainage holes are, took pictures to ensure that the composite geotextile solution was installed correctly, and noted down material reference numbers and locations. This information was related to the BIM model in the correct location which makes it far simpler to get exactly the information that we might need straightaway. The process is entirely automated which meant that there was no extra work for the team.

“A major challenge is constructing the defences in line with the design and then checking the defences to make sure that they are still functioning as designed over time. The rocks are placed in a specific pattern with certain sized spaces between them. These spaces allow the sea’s wave energy to be dissipated without causing any damage, each time a wave hits them.

“It would be far too slow and dangerous for a person to measure every single void and even more risky and onerous to try and record manual measurements for every rock placement. We solved this by using a GPS machine control solution which is mounted to the machinery placing the rock armour. The machine control solution accurately records the actual GPS position of each placed rock. The GPS output is attached to the Sitedesk site diary which provides a real time ‘as built record’ of how the defences are being constructed. This data is then automatically attached to the correct grid and the BIM model.

“To gain a picture of how the defences look when they are first completed, we are using a Quadcopter to record HD video of each section. In a similar way to the GPS rock placement, the video is being added to the Sitedesk site diary which gives us a complete ‘as built’ picture as well as any notes or comments that we have made during the construction process. This minimises risk to the defences, lives and property, as well as the public purse

“We have created inspection forms in Sitedesk that allow us to capture all of the operational and maintenance data that we need. Once the maintenance processes commence we will fly the drone over the defences and record the condition of the assets over time. This gives us the facility to see how the defences are performing, as well as identify any problems by comparing the data sets and by viewing and comparing the videos. Sitedesk is helping minimise time, costs and risks to the project by delivering three things in one solution. A risk management tool that helps us measure, validate and mitigate risks as the project progresses, a digital asset management solution to manage the asset which we are constructing as the project progresses and a maintenance and inspection tool that we can use to manage anything that is in, on or related to the project.”

Lessons learned so far

For Green, the biggest lessons learned so far are:

  • To identify areas of risk early, and specifically capture data which allows rapid identification and management of the issue;
  • Test the risk management process with trial scenarios so you know that the data sets and processes that you have identified will work when you need them;
  • Validate data as you go along. It’s too big a job to do at the end of the process. It will probably be too late to address any construction issues unless you identify them as you go along;
  • Embrace technology but ensure that there is a solid business case driving the adoption otherwise you will get data for data’s sake;
  • Build your O&M solution as you go along. It’s cheaper;
  • Choose technology that is easy to use. If it isn’t people won’t use it.

Carl Green

Head of Engineering Services

Wyre Council

Carl.Green@wyre.gov.uk

www.wyre.gov.uk

www.twitter.com/wyrecouncil

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