Monday, 3 February 2014

Good Connections

James Wood – Piletech Manager

One of the benefits of screw piling is the speed with which it is delivered on site.

The final process on site within the piling sub-contract usually involves the connection detail.  This is typically achieved by placing reinforcing bars into the concrete infill within the steel tube of the screw pile.

A typical Screw Pile Connection

However, there are many ways to form a connection, dependent on load requirements.

A few of the more common examples are:
  • Reid bars with flange plate nuts
  • Annuli - welded to the pile
  • Cage style arrangement where pile allows
  • Shear studs or dowels
Where possible, we will propose the use of straight bars - this makes it easier for following trades to place cages, saving further valuable time on site.

Typically the screw pile designer will propose a connection detail.  However as the connection detail can affect what happens above it, the structural engineer's involvement is required to ensure design requirements are met.  A collaborative approach to this element ensures Good Connections - a technically suitable and economical result.

Factors to consider when developing connection:
  • Design loads
  • Bar development length
  • Bond between concrete and pile wall (typically this is greater than bar development)
  • Minimum steel to concrete ratio
  • Constructability for following trades
For more information about design and connection of screw piles, contact one of our team or visit: