SAS13 Bridge Replacement

Project Overview

The SAS13 bridge replacement project, situated near Birmingham City Centre is an enabler for HS2 on behalf of Network Rail. The scope involved demolishing eight spans of an existing nine-span viaduct and replacing it with a new single span bridge.

JGL were appointed to support with this project and provide two shafts (4.5m ID) and concrete works, working with ground conditions of mudstone, stiff clay and siltstone. The installation of grout curtains was completed prior to us excavating the 2 x shafts.

Challenges

The biggest challenge we faced was having to work in extreme close proximity to the live railway lines (Derby lines and Stechford to Aston line) near the existing bridge structure. We were working within approximately 500mm of the live bridge.

Given the working confinements - the team coordinated all planning and ALO (any line open) plans with Skanska and Network Rail, ensuring that all plans were approved prior to works going ahead for our works and that of other contractors working on the same section e.g. Kellers completing 2 grout curtains around both of the shafts we built.

Time for approvals and communications were factored in to ensure their were no delays to the programme.

Added Value

• We used a Siltbuster by the designated discharge point to over pump the shafts as needed.
• Flows were measured several times a day by the team to ensure wastage was kept to a minimum and in accordance to the permit to pump guidelines.
• PH readings were also carried out in the settlement tanks to ensure that the value was as per the permit to pump range.