The extreme rainfall had caused the ground to slip at the top of the wall, leading to the collapse of the wall into the highway. Whitehouse worked with DCC through continuous contractor engagement to ensure the correct solution was engineered, causing the least disruption to local stakeholders.
The initial design comprised of a CFA piled foundation with a concrete wall along with ground anchors to secure the wall and prevent reoccurence of the incident in the future. We completed Site Investigation works prior to the commencement of the main scheme, which included undertaking a test ground anchor to finalise the proposed design. During this test, we concluded that the existing ground conditions were more suitable than initially assumed by the designer. We worked with DCC to revise the design, removing the need for CFA piling and half of the estimated muck-away, providing £35,000 in cost savings for DCC.
As the initial collapse was due to the volume of water that had soaked into the topsoil, we worked with the designers to improve the design for water reduction. Additional drainage was installed at the back of the wall to allow the water stored in the ground to travel through into a gravelled area below. The water is then released through weep holes in the wall. This reduced the overall volume of concrete required and the risk of alkaline water leaching into nearby ground.
Although the wall itself was not of historical significance, it was of great importance to ourselves, DCC and local residents that it was retuned to its former glory. Extensive online research was undertaken to ensure reinstatement was in-line with the surrounding area and historical records.
Significant stakeholder liaison was required to ensure minimal disruption to local residents. We held an engagement event to capture concerns raised by the residents. Findings from this event allowed us to re-design the site layout to ensure maximum accessibility to the surrounding properties.