Vegetated Retaining Wall 

Webwall Geocell for Cycle Path Down Steep Slope, Westfield, Pembrokeshire

Project Information

Project Description

Westfield Pill nature reserve is on the edge of the Cleddau river near Milford Haven, and is home to part of the National Cycle Network Route 4, also known as the Celtic Trail. This section links two existing shared use paths, the Brunel and Milford Haven trails, to the Pembroke route. An improved link was commissioned to join the high level Milford Haven trail to the lower level Brunel trial via a zig-zag path to accommodate the change in levels.

The Challenge

Pembrokeshire County Council worked closely with the Wildlife Trust, firstly to mitigate the impact improvements to the foot and cycle paths would have to the nature reserve and, secondly, to promote biodiversity on this former railway route. To achieve this, improvements needed to meet strict design criteria and provide multiple environmental benefits, including promoting recolonisation of the area by native flora and fauna.

Retaining walls were needed to reduce the gradient of a descent used by cyclists and walkers and to improve accessibility for less physically able users. Traditional gabion basket or concrete based solutions would not meet both the environmental and structural requirements of this project.

The Solution

ABG proposed a design incorporating a Webwall geocell facia reinforced using Trigrid EX Geogrid and with structural drainage achieved using Fildrain geocomposite. The proposal was developed to meet all the site requirements, and ABG provided full detailed design and supervision of the construction.

Webwall geocell is a three dimensional cellular confinement system designed specifically for building and facing reinforced earth systems. Webwall uses site won material in its honeycomb cellular structure as backfill, reducing the requirement to import expensive quarried aggregates.

Trigrid EX geogrid is designed to promote interlock with the fill making it ideal for this earth reinforcement application.

Fildrain drainage geocomposite was used behind the wall to control groundwater pressures.

Once constructed Webwall was seeded with plants selected to enhance the local environment. This provided a pleasing biodiverse vegetated facia for the lifetime of the wall.

The ABG Service

ABG provided conceptual and detailed design support during the design phase of the scheme, and supplied materials and supervision of the construction on site.

Contact ABG to discover how Webwall geocell could help you deliver a sustainable, cost efficient and carbon neutral solution.