Dawlish Emergency Works

Synopsis:
Network Rail’s designer for the repairs to the storm damage
Client:
Network Rail
Awards:

On 4th February 2014 storm damage caused an 80m long breach in the railway line near Dawlish Station. As the on-call engineer for Network Rail Wales and West, Tony Gee was called out to site to assess the damage. As the only designers on the project, we worked collaboratively with Network Rail and the three main contractors – BAM Nuttall, Amco Rail, and Dyer and Butler.

A further 400m of parapet wall, 300m of copers and walkway slabs, six staircases, two sea wall ramps, and three breakwaters were damaged between Dawlish and Teignmouth. In total we inspected, logged and recorded 137 structural defects caused by the storm damage and detailed their repair.

Immediate works were undertaken to protect the area from being undermined further by the tide; sea containers were filled with debris/ballast to form a protective barrier to the works area. High tides and poor weather restricted work to short length low-tide cycles. Sprayed concrete was used within the side slopes of the hole to prevent the fine sand from washing out further and protect undermined residential properties. On 14th February a second storm caused further damage extending the breach by 20m and increasing the quantities of other wall defects.

By using staggered rows of precast vertical concrete barriers (VCBs) as facing shutters on the seaward face, the breach was filled with four lifts of mass concrete. The VCB face was tided back into the mass pour to ensure a composite unit was created. Subsequently two rows of anchored L-shaped precast retaining wall units were installed along the sea wall edge and along the adjacent access road to support the new track formation.

Coastal services included MetOcean back analysis, sea wall design and construction sequence risk analysis.

Once complete a new ballast bed and track was laid. This section was opened to trains on the 4th April 2014, eight weeks and four days after the damage occurred.

We also assisted Network Rail with the design and construction of a short term resilience scheme at Dawlish, providing design services and support with the licencing.

Read about Tony Gee’s involvement in the Dawlish Sea Cliff Stabilisation.

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Dawlish Emergency Works