- Project: Great Western Park, Didcot
- Principal Contractor: Agetur, UK
- Project Lead: Ray Hind, Technical Sales
- Lead Engineer: Lee Womersley, Engineering Manager
- Key Benefit: Solution minimised installation time for temporary works and reduced overall cost
Introduction
In 2015, MGF were asked to provide temporary excavation support to facilitate the construction of an Insitu RC tank at the Great Western Park housing development site, located in Didcot.
Principal contractor Agetur UK, had an existing close working relationship with MGF’s Ray Hind
and from this, requested assistance on the provision of design to suit their support requirements for three tank walls. With tight lead times due to the Christmas Break, work began to quickly complete the scheme before the break.
The Solution
The overall geometry of the scheme was challenging, with the added problem of an unforeseen service that encroached onto the proposed excavation. The excavation also needed to allow for nearby roads on two sides to remain open, the complex shape lent itself to using proprietary modular frames to enable a quick, yet safe economical solution which was provided by MGF’s engineering team.
As part of the design, MGF needed to ensure the solution did not impede on the permanent works at all stages, resulting in maximum prop spacings to allow an easier digging window with the frame located above the pour concrete sequence. This also allowed for the construction of a ramp to ease the use of materials to construct the base and RC walls.
To facilitate the design, an array of equipment was utilised including KKD 600/6 Trench Sheets, 254UC
tank brace and 305UC brace combined with 200/300 series bracing struts.
With an overall depth of 2.90m, the excavation required a single frame with a toe solution, also known as a propped cantilever. The reason a propped cantilever solution was chosen was to reduce the time on site needed to install the temporary works.
The overall frame assembly was quite complex, so the MGF team removed the need to repeat the assembly with the second frame as it would ultimately need to be removed, therefore adding more time and cost to the project. Through adequate soil investigation of the works, ground conditions could be anticipated before formation level. In all, stability of the excavation was achieved whilst minimising sheet lengths and programming onsite.
The Verdict
As a result, MGF’s quick response showcased excellent communication between the contractor, MGF sales, engineering and operational teams.
The solution allowed construction of the permanent works at ease whilst minimising installation time for the temporary works and ultimately cost to the contractor.
