Stabilising weakened and bowing rail bridge masonry

Bridge 31/33, Basingstoke

  • CLIENT : Network Rail
  • INSTALLER : Dyer & Butler


The supporting walls of Bridge 31/33 on the Reading Road in Basingstoke were becoming weak and beginning to bow as a result of age and weather erosion and needed to be quickly and effectively stabilised.

Richard Jackson Partnership specified the well proven stainless steel mechanical ground anchors, having had previous good experience of the products.

After sound testing a design repair was finalised and undertaken.


The mechanical ground anchors, with 6m x 20mm stainless steel high yield bars, were rapidly driven into the made ground of clays, rubble and granular material. Installed in two rows on either side of the bridge arch walls, the anchors were terminated with 350mm x 350mm x 8mm stainless steel plates and nuts.

The anchors were proof loaded to 60kN and then set to a working load of 30kN.

Despite the difficult access and the restricted time frame for the project, all the mechanical ground anchors were successfully installed and set within the allotted time and no grout was spilled over the footpaths which had to be kept open.