Project: Fothergilles Road, New Tredegar, Wales.

Principal Contractor: Dawnus Construction

Scope of Works: Van Elle carried out Installation of 29no 660mm Temporary Cased Drilled Piles to a design depth of 13m, and installation of 29no 220mm permanent cased raked positions for Multi Strand tie back anchors.      

Plant and Equipment utilised: Klemm 709 -9m, and Numa P125 DTH Hammer with 610mm Button Bit For King Post Piles, And Numa T195 Super Jaws Overburden Drill Systems to install 220mm permanent casing for Multi Strand tie back anchors.       

The required works were carried out during day shift working hours within a full road closure. The existing road was monitored throughout the piling operations for further movement. King post piles were temporarily cased to 4m into weathered mudstone, and the pile advanced using 610mm DTH into Limestone to form a 4m rock socket. Following the installation of the kingpost piles, 8 strand SBMA anchors were installed through each king post UC section. 220mm permanent steel casings were advanced 30 degrees through the over burden material using a Numa T195 Super Jaws drill system. 

Casing was advanced to a depth of 13m and a rock socket then drilled out the end of the 220mm casing to the required design depth. SBMA anchors were then installed following water testing of the anchor bore to prove integrity. Grout was then batched on site and pumped into the anchor through factory installed stage grouting tremies. Following the specified curing period for the grout, the anchors were then tensioned to the required design specification and the heads of each anchor locked off. The anchor head was then coated against corrosion inline with specification, and each head sealed of with a purpose built top hat cover.