DON STREET PUMPING STATION DEVELOPMENT IN SOUTH YORKSHIRE
LECA® LWA was recently specified for the new Don Street Pumping Station – a flood defence scheme developed by Rotherham Metropolitan Borough Council, which was designed by 3E Consulting Engineers and delivered by main contractor Breheny Civil Engineering Ltd.
On an unused area of scrubland in Rotherham, South Yorkshire, the erection of a pumping station on Don Street was required with the key component of the flood protection scheme being works to the Holmes Tail Goit watercourse, specifically the installation of a new pumps designed to force surface water into the River Don in the event of any flooding.
The pumping station development was developed to act as a key element of infrastructure contained within the flood risk strategy for the surrounding areas. This has involved land levels being raised by 2.5 metres using infill to reduce the risk of flooding. Also retaining walls, embankments and culverted drainage system have also been utilised.
Over 1300m3 of LECA® LWA was specified and delivered by Walking floor (which can carry up to 70m3 per delivery) as a lightweight backfill against abutment walls of the new pumping station which had differing levels – resulting in problematic long term ground work issues.
To tackle this issue, it was originally proposed that horizontal piles were to be implemented, but the developers recognised that this would create a serious cost issue, so an alternative solution was sought out to tackle this issue and LECA® LWA was discovered as a key solution to overcome this issue.
Amount of material: 1300m3 of LECA ®LWA (10-20mm)
Interesting Fact: It was originally proposed that horizontal piles were to be implemented to tackle differential groundwork levels, but the contractors recognised that this would create a significant cost implications
Delivery Method: Walking Floor
Main Contractor: Breheny Civil Engineering Ltd
Senior Quantity Surveyor at Breheny Civil Engineering, Ben Schofield stated that “LECA® LWA was chosen for its lightweight properties but also its high strength, the pumping station had differing levels to either side of it giving rise to a large horizontal resultant force. Following extensive research, it was decided that LECA® LWA was the best solution as this would provide a light density fill but would still be able to carry the live load surcharge removing the need for more expensive alternatives such as horizontal piles.”
The delivery of the material has been successful thus far and has provided the stability and lightweight properties required for this project. Project Manager at Breheny Civil Engineering, John Coyne added that “…the alternative would have been racking piles in order to carry the high horizontal load, which would have cost more and added time to the programme”
Following the works, Breheny Civil Engineering Ltd would recommend the use of LECA ®LWA and are now considering it’s use as potential value engineering due to its much shorter programme durations and favourable compaction properties compared to other aggregates.