Case Study: M1 Junction 23a – 25 Smart Motorway

M1 Junction 23a – 25 Smart Motorway

Contract No:C1236
Client:Costain Galliford Try Joint Venture
Location:M1 Motorway, East Midlands
Value:Approximately £ TBC
Summary:Design, supply and sheet pile installation of approximately 2100Te of Z section sheet piles to form permanent emergency refuge areas.

The Highway England scheme involves converting the M1 into a controlled motorway between Junctions 23a and 24, and an all lane running Smart Motorway between Junctions 24 & 25.

The overall length of the scheme to be upgraded is 7.5 miles (12km) – Main Construction commenced in July 2017 and completion is due late 2018/early 2019.

The scheme involves:

  • Permanent conversion of the hard shoulder to create a fourth lane between Junctions 24 & 25 including changing the junctions to accommodate.
  • The introduction of variable mandatory speed limits with an associated enforcement/complaint system.
  • New CCTV cameras and electronic information signs and signals on gantries, these will show the variable mandatory speed limits and manage traffic flow and incident.
  • Emergency refuge areas throughout the length of the scheme.
  • The hardening of the central reservation and installation of a reinforced barrier to improve safety.
  • Emergency roadside telephones (ERT) provided within emergency refuge areas and in locations where the hard shoulder is retained.
  • Queue detections and automatic signalling system which provides queue protection and congestion management.

The overall aims of the scheme is to:

  • Reduce congestion and smooth the flow of traffic to improve travel times and make journeys more reliable.
  • Support the economy and facilitate economic growth within the region by providing increased capacity thus reducing the cost of economic delay to commuters and business traffic.
  • Maximise motorway capacity while maintaining safety.
  • Minimise environmental impacts.

The approximate construction cost of the scheme is in the region of £120 million.

Sheet Piling (UK) Ltd – (SPUK) were approached by Costain GallifordTry JV (CGT JV) to provide quotations for various sheet pile installation cost plans and options in April 2017.

Due to the fast track pre-construction strategy in place on the project, there was only a limited window of opportunity for providing ground surveys/value engineering/detailed tender enquiry.

As such, from an early stage, Sheet Piling (UK) Ltd worked in close collaboration to provide design, sheet pile installation, operational, procurement and costing advice to ensure the sheet piling works commenced on programme in August 2017.

This advice on a couple of structures involved recommending alternative solutions to the conforming solutions as these could not be procured or delivered to the required programme.

To ensure the construction programme was maintained, Sheet Piling (UK) Ltd offered a reduction lead-in period by supplying ex-stock sheet piles from the company’s significant stockholding of 8000Te piles. The use of ex-stock piles avoided programme delays which would otherwise have been incurred from ex-mill rolling’s.

Due to the precise planning required and interfaces with other trades; Sheet Piling (UK) Ltd produced detailed layout ad sequence drawings for each location. This ensured that, where possible, all trades could work in a safe and proficient manner; minimising disruption and maintaining the works programme. This was a good example of early contractor collaborative planning which was in place throughout the project.

In respect of the detailed sheet piling package programme, Sheet Piling (UK) Ltd provided a dedicated pre-augering and pile installation gang on both the north and south bound carriageways. This involved utilising four of Sheet Piling (UK) Ltd’s fleet of telescopic leader rigs and two Sennebogen Telescopic Crawler Cranes.

In total, approximately 2100Te of ‘Z’ Section Sheet Piles were installed to construct the specified King Sheet Pile (KSP) and traditional sheet piles walls. The sheet pile installation works were successfully completed between August 2017 and February 2018 to the mutual benefit of all parties.