2020
WINCHESTER - HAMPSHIRE - United Kingdom
Private
P C Construction & P J Carey
WINCHESTER SERVICES, M3 MOTORWAY
WINCHESTER SERVICES, M3 MOTORWAY_0
WINCHESTER SERVICES, M3 MOTORWAY_1
WINCHESTER SERVICES, M3 MOTORWAY_2
WINCHESTER SERVICES, M3 MOTORWAY_3
Challenge
The proposed service area was located within an environmentally sensitive ancient woodland, where preserving the natural landscape was a critical concern. Local conservation groups strongly opposed any intrusive construction methods, and following a formal enquiry, a traditional reinforced concrete retaining wall solution was ruled out. This created the need for a more sustainable and environmentally friendly engineering alternative.
The project also faced strict technical and spatial constraints. The design was required to comply with Highways Agency standards for strengthened earthworks, including achieving a minimum design life of 60 years. Additionally, the solution needed to be compact, with a construction footprint confined entirely within the existing highway boundary to avoid impacting the surrounding woodland.
A key requirement from environmental stakeholders was that the solution should deliver a “natural” engineering appearance, blending seamlessly into the landscape and avoiding visually harsh or artificial materials.
Solution
Maccaferri gabion retaining walls provided an ideal solution, successfully combining structural performance, sustainability, and environmental integration. Gabions offered a durable, flexible system capable of meeting the 60-year design life requirement while delivering a natural aesthetic suitable for sensitive environments.
To minimise disruption, both carriageways of the M3 motorway remained fully operational throughout construction. The gabion walls were designed with a compact footprint of just 3.5 metres, enabling installation entirely within the existing hard shoulder and eliminating the need for additional land take.
Due to restricted working space and challenging site logistics, a 24-hour construction programme was implemented. Chalk slope cutting was carried out during daytime operations, while gabion wall installation took place at night. Specialist contractor P C Construction installed a total of 5,500 cubic metres of gabions, achieving an average installation rate of 140 cubic metres per night. The Green Terramesh soil reinforcement system, installed by P J Carey, further enhanced the structural stability of the earthworks.
From an environmental perspective, the project prioritised ecological integration. Landscape architect McGregor Smith recommended a natural stone finish rather than pre-seeded topsoil. This approach allows the gabion walls to naturally vegetate over time using local plant species, ensuring seamless landscape integration while preventing the introduction of non-native vegetation into the conservation area.
Used Products
