The front seawall consists of an in-situ concrete toe founded directly onto the chalk foreshore with mass concrete precast facing blocks and coping. There is an in-situ concrete berm/promenade and a low precast concrete rear wall. The upper course of seawall blocks and seawall coping have moved seaward by some 180mm and are at risk of coming away and falling off.
The three work areas (659m total length) are all located on the North Thanet coast of Kent over a 3km length of coastline from Grenham Bay to St Mildred’s Bay. The upper course of seawall blocks and seawall coping had moved seaward by some 180mm and were at risk of coming away and falling off. This would have resulted in erosion of the fill behind and undermining of the promenade slabs and rear wall.
The whole of the North Thanet coastline has international and national nature conservation designations. The area is a Site of Special Scientific Interest (SSSI), Special Protection Area (SPA) and a Special Area of Conservation (SAC). Of particular importance are the chalk reefs in the inter-tidal area and the presence of Turnstones in the winter months.
A programme of works was undertaken to replace the displaced seawall blocks.
Works to replace the seawall blocks comprised the following:
- Replacement of pre-cast seawall coping block
- Realignment or replacement of the upper course of seawall blocks
- Replacement of promenade slab
- Repair of insitu reinforced concrete toe beam
- Replacement of aluminium hand railing