Holdfast Training Services Trial Blog

Victoria Square Woking are currently in the process of removing the existing shallow foundations of an old car park so they can construct CFA piled foundations for the new car park.

The demolition contractor are obligated to leave site with 1) the guarantee there is no existing structure in the ground and 2) the ground is of sufficient strength to support the piling (create a piling mat)

Yesterday on site the demolition subcontractor brought a plate bearing test team onto site to ensure the sub grade was of a high enough capacity before continuing up. An intermediary test. I thought I would share the test in case any of you were interested.

Effectively what is happening is a plate is placed under one of the excavator machines and a hydraulic jack is connected to the two. When the jack is lifted a gauge informs the operator what pressure the plate is under.

A scaffold tube is placed next to the plate with three strain gauges fixed to the plate. The differential movement between the scaffold tube and the plate offer an immediate settlement value for the plate. Once you’ve got both pressure and immediate settlement calculations can be performed to give a CBR %.

I am still awaiting the report back but the guy on site said we achieved 25% which is good considering our specification was to hit 5%