Acton Storm Tanks (Syphon Main Diversion)

Project Overview

Joseph Gallagher are proud to have already completed several major projects for Thames Tideway across all three sections of the project since 2018.

Balfour Beatty, Morgan Sindall and BAM Nuttall (BMB JV)the delivery partner approached JGL to tender for the works, which involved the installation of a new 900mm diameter concrete pipeline and connections into two existing manhole chambers.

Following our appointment, the final scope of works consisted of installing two sheeted pits at 6m deep and microtunnelling a distance of 45m with final connections into the existing two manhole chambers.

Challenges

The single biggest challenge facing the project was the risk of settlement during the works. The correct method of works and sequencing was instrumental for keeping any potential settlement to a minimum. We proposed installing a line of driven sheet piles on the boundary side adjacent to the highway, where key utility services were located. Careful consideration was also given to the type of piling implemented, a pre-augering with a pile press solution was adopted as it allowed the settlement to be kept to a minimum.

There were multiple obstructions that needed to be removed as the shaft excavations proceeded downwards. This resulted in a 'dig a push' method for the remaining side of the shaft. JGL were able to lean on the Group's extensive services and resources to complete these complex works.