Innovation – Micro Piling Solutions

Aspin’s innovation in piling solutions is hard at work for Network Rail at sites across the UK. The unique micro piling technique overcomes the issues in hard rock areas where high strength piles are needed for structures such as OLE masts when traditional CHS-driven and augered concrete piles are not suitable.

It’s proven itself as a highly sustainable means of completing works thanks to a simple combination of equipment that gives ease of transportation access and handling for track teams.

The technique has been adapted for works at Kentish Town during the Christmas blockade where the existing 1970’s track slab was being replaced, providing a rapid, cost effective and sustainable solution that also minimised noise.

The track bed needed stabilisation to prevent the new concrete transition slab from sinking and any rotational movements. The Aspin solution positioned 20 new micro piles of 220mm diameter, installed with Aspin’s uniquely-adapted piling rig, powered directly from the Road Rail vehicle. It meant that there was no need for an additional power pack which reduced the plant on site, usage of diesel and noise pollution – a method favoured by the client over a traditional concrete auger pile for its speed of installation and minimal spoil, alleviating muck away.

In works for leading international supplier of consulting and infrastructure support services Amey, the Aspin team has provided a piling solution to hard ground on Network Rail’s Greater West Electrification Project (GWEP), Route Section 6D. The 1.5 miles of track had a four week blockade, during which time Aspin delivered 58 foundations as part of the OLE works. Plans are already in place for similar projects.

Two to three foundations were completed during a 10 hour possession, with minimal environmental impact. Each pile comprises a 150mm diameter bore which is reinforced centrally by a 76mm diameter hollow steel threaded bar then grout filled. The bore is formed by air flush rotational drilling with hammer assistance when driving the steel bar into rock or hard strata. Each pile uses a sacrificial drill head, the selection of which varies to suit the ground conditions. Air is blown through the threaded bar to the drill head where it is expelled into the spoil arisings and flushed out of the bore.  Once the design depth is achieved, the air is replaced with high strength grout which fills the external and internal cavities to create the finished pile.

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INNOVATION – New Micro Piling Solutions