Spire Geotechnical (SGL) recently conducted a detailed appraisal of land for a proposed residential development. Preliminary Risk Assessment Manchester was successfully completed.
The site in question included a small plot of land that is being considered for a future residential development. The existing structures on the site are due to be demolished. These will be cleared to make way for the new project build.
Our assessment commenced with a detailed site walkover. A walkover is a vital element to any investigation. Consequently, without a walkover, a geotechnical survey or desk study, important information will be missed.
From our visit, SGL noted cracking and subsidence on the existing structure. The structure is only 40 years old, and subsidence informs SGL that geohazards are present and these may impact the new building project.
In addition to the subsidence, SGL identified the presence of Japanese Knotweed (and invasive weed species) that is present near the footprint of the new building. Future groundwork would have undoubtedly disturbed the Knotweed. Consequently, SGL provided recommendations to manage this feature.
Our searches and review of available records and information revealed that the site is potential at significant risk from shallow coal mining in the ground. The subsidence in the structure strongly correlates to known coal workings immediately beneath this feature.
Key takeaways from Preliminary Risk Assessment Manchester are that without a site visit and a detailed walkover, vital clues and information would have been missed.