MGF's T700 Brace on site with Kiernan Construction

  • Project Installation of three large tanks
  • Principal Contractor Kiernan Construction
  • Project Lead Michael Thornton, Technical Sales
  • Lead Engineer Richard Rae, Senior Engineer
  • Key Benefit 26m open length utilising MGF T700 Brace
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Construction of a new 94-acre business park near Darlington required the installation of three large below ground tanks, one of which necessitated the use of MGF’s T700 brace.

Following Kiernan’s successful tender to complete the construction of the tanks, MGF were soon engaged to discuss and develop suitable, efficient temporary works designs.

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The Solution

MGF’s in-house design team soon determined that using an equipment combination of standard MGF hydraulic braces and bracing struts would have required the excavation to be significantly larger to accommodate the use of knee braces or cross struts which wouldn’t have been suitable to install the size of the tank. Therefore, in order to achieve a sufficient open span, whilst minimising the footprint of the excavation and the installation risk to the customer, MGF’s Design Team employed the use of our T700 frame.

Following an initial ‘Concept’ design and subsequent feedback from the customer, the final design solution for the cofferdam measured 26.0m x 6.2m x 7.0m (length x width x depth) and comprised of the new T700 brace working in conjunction with MGF’s existing heavy duty Tank Brace products: 406UC and 305UC in the top frame and 305UC c/w 400 series struts in the second lower frame, which was removed following the construction of a 300mm thick concrete base, to leave the top T700 brace as the only frame.

The Verdict

Despite the significant length of the open span, and the operation of heavy construction plant in close proximity to the excavation: observed deflections of the T700 were less than half the maximum 55mm calculated deflection therefore surrounding ground settlements were minimised.

Developed in order to achieve large industry leading clear spans, of up to 30.7m, the T700 is fully compatible with existing MGF heavy duty hydraulic bracing and bracing strut systems making it ideal for large (20m+ long) tank installations, which are becoming increasingly common.

We have a strong working relationship with MGF, built up over the years through excellent service.

Paul Troubridge, Kiernan’s Project Manager