- NEW J11A MOTORWAY JUNCTION
- CONSTRUCTION OF A 5KM LINK ROAD
- 7 MAJOR STRUCTURES
- 750,000M3 OF EXCAVATIONS
- PLACEMENT OF 260,000T OF CAPPING AND SUB-BASE
This £162 million project provides a new Motorway Junction M1 11A, between Luton and Toddington, which will connect a new 5km dual carriageway link road to the existing A5.
The scheme is intended to ease congestion in Dunstable, Houghton Regis and the surrounding area and to also facilitate the construction of 7000 new dwellings.
The main challenges for earthworks operations were to balance the cut/fill volumes (100,000m3 shortfall of suitable fill material), find permanent storage for the 150,000m3 of surplus topsoil and subsoil and reduce the modification of 30,000m3 of unsuitable material expected within the excavations.
In conjunction with the Costain Carillion JV, it was proposed that the link road design be amended, generating an additional 60,000m3 of cut material. Batters in the main cutting were widened and 6 on line borrow pits proposed and accepted, generating a further 50,000m3 of suitable material.
Surplus soil was reclassified as Class 4 material and placed in onsite landscape bunds and off-site sources, including the local golf club, were identified for re-use of surplus quality topsoil. Overburden initially intended to go into landscape areas was then utilised as back fill to the 6 borrow pits reducing the requirement for modification of unsuitable material to zero. All solutions combined generate a project saving of approximately £800,000.
Walters utilised large numbers of GPS and robotic controlled plant, allowing the CCJV to significantly reduce the number of setting out engineers required and Walters to trim all formations to the higher range of tolerances. With over 250,000m2 of area required to receive sub-base this generated a saving of circa £115,000 when compared with conventional methods.
Walters used the latest safety protocols when working adjacent to live traffic whilst also minimising the people and plant interface where possible.