Updated March 2021
Further detailed ground investigations are underway to confirm the cause of the collapse to the retaining wall at Belgrave Road in Ventnor in January 2020.
The findings will help engineers design and implement a scheme to repair the wall and re-open the road. It is envisaged that repair work could begin in early summer 2021 and be completed by the end of October. It is important that the next steps are decided based on sound evidence and the survey work should give us the information needed to design and implement the best possible solution.
In the meantime, visual site inspections continue to take place at both Belgrave Road and Esplanade Road twice weekly to monitor any wall movement and cracking at the top of the terrace and the middle and lower sections (and these will continue over the festive period). Additional inspections are also held after periods of bad weather. These inspections have shown no further significant movement, cracking or deterioration in recent weeks.
We have been carrying out a staged process of ground investigation work to determine the root cause of the failure of the retaining walls alongside the carriageway on Belgrave Road. This will then help us to identify potential solutions before we commission any work to rebuild the walls and reinstate the carriageway area.
The walls along Belgrave Road and those forming its terraces are over a hundred years old and there are therefore no records about their original construction. For this reason, the first step in our process is to ensure we have a better understanding of their composition and of the robustness and stability of the foundations particularly before we bring in any of the more substantial engineering machinery required.
During the first stage of this investigation, before Christmas, our consultant engineers undertook a process called vertical coring in which a specialist type of lightweight drill was taken through the carriageway surface up to around 4-5 metres deep. These small exploratory holes then enabled us to lower a video camera down the holes to establish the ground conditions beneath the carriageway. Similar horizontal coring was then undertaken through the masonry of the retaining walls so that we could investigate the thickness of the walls and identify the materials that sit behind them.
The ground conditions encountered and recorded through this process, together with historical information on the geology of the surrounding area, gave us the information we needed to be able to progress to the second stage of the ground investigation works in mid February. For this phase of the work we have been using specialist equipment to take core samples of the ground up to a depth of 15 metres deep. There are five such sampling sites in the vicinity of Belgrave Road.
The findings of these samples, and other data we have been gathering, will inform a detailed geological report which will feed into the work to design a solution to restore access to Belgrave Road. This initial geological report will be ready in April.
While the coring work in respect of Belgrave Road is nearing an end, the specialist equipment will remain on site for a few further weeks. This is so we can gather data in respect of the other retaining walls and highways in the immediate vicinity for which we are responsible. It is anticipated this additional work will be completed by the end of the month (March).
We do not anticipate this work will require any further changes to the local traffic management arrangements (both Belgrave Road and Esplanade Road remain closed to vehicles) although it may be necessary to restrict some footway use temporarily while the core samples are being taken.
It goes without saying that we will do all we can to complete the work in as short a timeframe as possible, though we must also ensure that at all times we maintain the safety of residents, local people and our workforce.
We would like to thank residents for their ongoing co-operation and understanding and we will ensure both they and the wider local community are kept up to date with the latest developments.
In the meantime, if you have any concerns please call Island Roads on 01983 822440 or email firstname.lastname@example.org