This connection into an existing 300mm main public sewer at 4m deep did prove to be a challenge with the confines of one lane as working space, but with our experience and rigorous process, it was completed within the timescale given to us by the client.
We used a dig-and-push method, featuring three levels of aluminium hydraulic braces, to create a new pre-cast concrete manhole over the existing 300mm main public sewer. The concrete surround was formed using pan shutters, then MOT Type 1 crush was compacted into layers, before receiving the correct number of passes with a petrol trench rammer to secure it. Edge sealer, tarmac and thermoplastic overbanding tape were utilised to finish the job properly.
Closing the road was not an option, as the site location was next to Saint Francis Primary School, and Newham Borough Council mandated that full access should be maintained at all times. We were, however, able to suspend the use of parking bays, which helped with storage of materials and waste, and put in place our usual type of exemplary NRSWA-compliant traffic management plan.