The Project
NTS (UK) has provided a unique ground support solution to JBF Group for the installation of two 24.7m long SPEL 600 series 300,000-litre tanks.
These tanks are being used as water storage for a sprinkler system used in one of JBF Groups’ projects on the Isle of Sheppey, Kent.
The Challenges
The site restraints would not allow for the tanks to be placed side by side. The trench required was approximately 5m in width and 52m long, a depth of 4.5m was also a key requirement for the excavation support.
Due to the sensitive nature of the equipment at the site, the vibration and noise from traditional sheet pile methods were not desirable. Slide Rails “dig and push” method allowed for a quick installation without vibration.
Installation of the tanks was also troublesome because of the tight site, requiring the tanks to be lifted by crane over the main building.
The Equipment
The Slide Rail system is exclusively available from NTS (UK) it is a modular component system that is used in the place of driven tight sheeting or Hydraulic brace shoring systems.
Also, by using Slide Rail’s unique tie-back system, maximum clear spans of up to 24m x 7m can be achieved without the need for any internal frames, enabling a reduced excavation footprint and commercial benefits surrounding backfill material within the support system.
The Solution
The NTS (UK) temporary works engineers produced a design that would leave a single cross strut support. NTS (UK) supplied 140 tons of Slide Rail panels & posts with 9 cross struts. Utilising Slide Rail’s unique tie-back system allowed for the removal of 8 of these cross struts to achieve two open spans of 25m.
Nobody was required to enter the excavation until formation was achieved. Entry was made, using NTS (UK) ladder platforms – these were accompanied by Emergency Safety Davit Systems and edge protection.
Once the tanks were safely placed, incremental filling of tanks and backfilling of the installation could commence at 350mm increments.
Technical Support
Our Engineering Team liaised with all parties concerned to achieve a safe and cost-effective solution. Both JBF Group and the main contractor were impressed with the speed of the installation, and the tight schedule was easily achieved.