The Project
This project involved connecting an existing manhole connection to an existing sewer following a new set of houses being built in a residential area in Leeds. This project therefore came under our Section 106 sewer connection service.
The Process
This project commenced by establishing traffic management, pedestrian barriers and Heras Fencing. Our operatives marked out the area of excavation and carried out a CAT & Genny survey to identify and mark up the location of buried services in the area.
The team then had to cut and break the road surface and begin excavating to a depth of 1.2m. At 1.2m shoring was inserted to a standard temporary works design for 3m deep sheets and walers.
Excavation continued along with shoring to a depth of 3 metres in order to locate, cut and connect to the existing 225mm combined sewer. The connection was made with a 225m x 150mm junction.
The next stage of the process was to lay a 150mm diameter clay pipe, surrounded in 10mm pipe bedding, at a 1 in 40 min fall to the edge of the excavation. The open end of the pipe was then compacted using a Heavy Rammer in accordance with NRSWA Table A8.1. Shoring was then removed in accordance with the temporary works design as backfilling progressed. The road surface was reinstated in accordance with NRSWA specification for the Reinstatement of Openings in Highways for Type 4 flexible roads.
The existing traffic management was then taken down and the site was re-established on the opposite side of the road in order to continue the sewer connection into the existing housing development site. A trench was then excavated to the site boundary, to the same method as above, breaking the road surface and excavating and shoring to the depth required for laying the pipe at the correct 1 in 40 fall.
Once this excavation was complete, clay pipe was laid, approximately 8m in length surrounded by 10mm pipe bedding.
The road and road surface were then reinstated in accordance with the guidelines cited above. The site was then taken down and traffic management was removed.
The Result
The result of this work was a successful connection of the existing manhole to the existing combined sewer.
