Hastings Pier Wins Highly-Prestigious 2017 RIBA Stirling Prize
It was announced this week that Hastings Pier in East Sussex, a major community-led regeneration project designed by dRMM Architects, has won the 2017 RIBA Stirling Prize.
Hastings Pier was originally designed by renowned Victorian Engineer Eugenius Birch and opened in 1872. The 140-year-old Grade II structure was significantly damaged in an arson attack in October 2010, following years of neglect. Hastings Pier Charity bought the Pier in August 2013 in order to drive the Pier’s restoration and manage its future. A development plan was put forward to the Heritage Lottery Fund, who awarded a project grant of £11.4m towards the £14.2m needed to restore the pier. Additional funds were raised through a Community Share Scheme.
The restored pier retains its sole remaining building, the Victorian pavilion, which has been carefully conserved and adapted into a restaurant, plus a new Visitor Centre called ‘The Deck’. The new Visitor Centre required new columns and piles to support it in the centre of the pier.
A Structurally Challenging Ground Investigation
Southern Testing’s involvement with Hastings Pier dates back to late 2013 when we were first approached by Hastings Pier Charity to assess the feasibility of completing borehole drilling from the existing fire damaged pier deck, at a point approximately 10m above sea bed level. The purpose of the ground investigation was to determine and characterise the underlying ground conditions to provide geotechnical parameters for design of the piled foundations supporting the new Visitor Centre.
The task was challenging due to the poor condition of the remaining fire damaged structure and the risks of working over water. Maintaining the spirit of innovation and versatility which Southern Testing pride ourselves on, various site investigation options were considered and discussed with Hastings Pier Charity. Our project Engineer and Field Operations Manager visited site to assess the physical and structural loading issues relating to access and discuss the necessary strengthening works before the drilling could start.
Dimensions and loading details for the proposed drilling rig, tools, casing and equipment were provided, allowing the Clients Structural Engineers to fully assess the degree of strengthening works required to allow the drilling to progress safely.
The north end of the Pier (onshore) is crossed by the White Rock Fault which runs NE – SW. The NW downthrown side of the fault shows the site to be underlain by the Tunbridge Wells Sand Formation composed of mudstones, silts, sandstones and ironstones, which in turn is underlain by Wadhurst Clay Formation composed of shales and mudstones with subordinate beds of silt, sandstone, limestone and ironstone. However, the geology to the southeast side of the fault, which includes the entire overwater section of the pier is not recorded on the British Geological Survey sheet.
The geology recorded immediately southeast of the fault and to the east of the site of the pier showed the area to be underlain by the Ashdown Formation which are composed of fine grained, silty sandstones and siltstones with shale and mudstone. With no further information available it was thought likely that the underwater geology of the site was comparable to the geology of the land to the east, and probably overlain with sand and gravel associated with sea bed and beach processes.
Southern Testing were awarded the ground investigation Contract for the new Visitor Centre on Hastings Pier with two phases of borehole investigation in 2014 and 2015. UXO clearance work was completed in advance.
Borehole drilling was completed overwater from the newly strengthened pier deck (at a height of approximately 10m above bed level) by our in-house drilling team with our Comacchio Geo 205 rig, using rotary drilling techniques to a depth of 35m below deck level. Symmetrix overburden drilling methods were used initially to form the borehole in the superficial materials. Cased rotary core drilling methods were then used to form the remainder of the borehole and to obtain core samples in the underlying bedrock.
On both occasions the recovered cores were logged and photographed on site by our full time supervising Engineering Geologist and then transported to our in-house laboratory for detailed soil and rock testing and analysis.
Factual information was provided to the Engineer (Ramboll) to aid pile design.