Case Study: Shildon Tunnel

Client Amco
Project Coring on retaining wall, installation of anchors and pointing work.
Location Shildon, County Durham
Overview TRAC were appointed by AMCO to carry out geotechnical works at Shildon Tunnel Retaining Walls to retain an existing bulge identified by AMCO as a potential threat to the Network Rail Infrastructure.


The geotechnical works comprised of marking out and coring 33No 150mm diameter holes through the existing retaining wall before installing 33No 32mm stainless steel sacrificial anchors to a depth of 3.8m into solid rock at an angle of 50®. Upon completion of grouting all anchors, 11No stainless steel channels were lifted into place with welded packers to ensure a smooth level finish was gained in line with the retaining wall itself. To complete the works, stainless steel plates, nuts (torqued) & end caps were fitted before being sealed with butyl rubber to prevent water ingress and any potential corrosion.
In addition to these geotechnical works, TRAC installed 11No weepholes in between the stainless steel anchors (to assist with drainage) whilst also assisting AMCO with pointing works as well as the transportation of scaffold to and from the Shildon Tunnel Retaining Walls site.
TRAC complied with all testing requirements by carrying out suitability and acceptance pull testing of the anchors as well as sending grout cubes to a laboratory for crush testing. These forms of testing ensured TRAC’s works were fully compliant with the designer’s specification.
TRAC’s scope of works were completed utilising their own RRV excavator complete with a Marini CID 120, RRV Genie Booms and RRV Renault Lorry complete with hi-ab and flat bed. TRAC’s machines were utilised for various tasks such as marking out, coring, sacrificial drilling, lifting operations, pointing and transportation.


TRAC’s scope of works were completed within AMCO’s specified programmed and TRAC’s calculated budget.