BridgeCare

USL BridgeCare Secure Embankment Stabilisation Project

The embankment near the Peel Centre is approximately 7 years old, and has suffered from design and installation issues since construction.

The Gabion wall itself is 200 metres in length and 5 metres in height and a depth at footing level of approximately 4 metres. The contributory factors to the failure of the wall included:

  • Inadequate construction materials
  • Incorrect installation of the gabion structure
  • Poor use of reclaimed materials within the embankment

Prior to the works commencing, sections of the wall were clearly noted to be bulging forward with large voids evident in the gabion blocks.

USL BridgeCare proposed a bespoke solution to deal with the issues identified

  • Seal the front of the gabion wall using shotcrete
  • Injection of grout to fill voids and bind the structure together utilising the steel mesh present as reinforcement.
  • Install weeps holes at the base of the structure to allow the embankment to drain.

The client requested that USL design a system and method to ensure 100% void penetration.

Our team submitted plans and method statements that incorporated a system of 'PRIMARY' and 'SECONDARY' ports. This was ultimately approved by the clients Engineer. Secondary ports were installed horizontally to the face of the gabion wall, whilst Primary ports, used for the injection of grout, were installed vertically through the embankment

Initial pre-contract estimates suggested around 15-20% void and an approximate 550m3, which would require 700 tonnes of material.

Gabion wall

Above: Gabion wall prior to commencement of works

Gabion wall

Installation of secondary ports - these facilitate the tracking of the grout flow underground providing a roadmap of progress.

Secondary ports were installed at varying depths ensuring that ports remained open following shotcrete application. This removed the need for percussive drilling into the face of the wall during grout injection. 

The gabion wall post shotcrete application - cosmetic finish not required due to new gabion structure to be placed in front of it. 

USL were able to modify the 2, 3 and 4m primary piling rods on site to facilitate the injection process - this modification was made to ensure that piling could be carried out on the embankment without the need for heavy lifting of percussive piling equipment above knee level.

 Gabion Wall

Image above shows piling and injection tests at 1 metre back from the face of the gabion. Once piling is complete design of rods allows operatives to simply unscrew the piling head from the rod and attach the injection threads - hi pressure injection hoses are then attached and injection can begin.



Contact Us

 

 

For more information on bridge deck preparation, expansion joints and waterproofing please call...

 

Call: +44 (0) 844 417 0720


Copyright © Universal Sealants UK Ltd 2017.
Privacy Policy | Terms & Conditions

To ensure we offer the best experience possible, this site uses cookies. By continuing to navigate our website, you consent to cookies being used. To learn more and find out how you can disable cookies, visit our Privacy Policy.