Due to failure of part of the face of the sea wall in Harwich between The Spa and Stone Point, significant voiding has been exposed below the promenade. This needs to be addressed quickly in order to mitigate the issue and protect from further failure. A consulting structural engineer and a coastal engineer have both agreed that we try a lightweight geopolymer solution to address the voiding, with a note of caution that it should be carried out by an experienced provider. Geobear have carried out this type of coastal work in other areas of the country and have successfully delivered underpinning using geopolymer for Tendring District Council.
Geopolymer is applied without having to excavate the promenade, one borehole for an application tube and one for a monitoring camera in the area of the void is all that is required, saving money on reinstatement cost as well as minimal impact on public use of the area.
Geopolymer is lightweight, not affected by water and cures in 4 - 10 minutes meaning large voids can be filled quickly. This is very beneficial in locations where the tide is a factor.
An agreement from the Corporate Director for Operations and Delivery and the Leader of the Council and Portfolio Holder for Finance and Governance has been obtained to grant a procurement exemption under Section 2.1 (c) of Part 5 of the Council's constitution.

To appoint Geobear to carry out void filling in the Harwich Promenade using geopolymer.

Option 1 - Appointing a company to carry out a concrete fill: Due to the size of the voids, the professional advice received is that the weight of the concrete would be too much for the facing wall structure. It would also have to be applied in stages allowing each application to fully set prior to the next section being applied, significantly increasing the timeframe and therefore weather/tidal risks.
Option 2 - Appointing a company to carry out a soft material fill: The promenade would need to be dug up and then reinstated, significantly increasing costs. Adding to this, soft fill is what is currently in this location and is gradually being removed by the wave action, meaning this would only be a short term solution and would not resolve the issue long term.
Option 3 - Appointing a different company to carry out a geopolymer fill: Whilst there are a small number of other companies providing this service, the advice received from the independent consulting coastal engineer is that it is important to use an experienced company. Geobear are the market leaders in this area, have provided details of where they have successfully completed a job in similar circumstances and have successfully completed a job for Tendring District Council in other circumstances, in which they delivered exactly what they said they would.