Failure in construction of 8 new pitches
The Cheshire East Borough Council entered into a contract with a construction company for the development of an entire new football complex for Sandbach United Football Club. In addition to structural developments and the construction of a synthetic grassed pitch, the project incorporated the establishment of eight grassed pitches.
After the official opening in May 2012 the lack of effective drainage resulted in most of the pitches becoming un-playable from September to the end of the season. As a result of the failure an intensive investigation was carried out and is summarised as follows:
- A topographical survey of the entire site was undertaken
- Trial holes were excavated to assess the depth of topsoil and variation in the subsoil
- The gradients were assessed together with consistency in levels
- The drainage design which incorporated lateral drains feeding carrier drains that discharged in to eight soakaway chambers constructed with Wavin aquacells
- The condition of grass cover
- The infiltration rate in the sandy loam topsoil
- A further eight trial pits were excavated and completed with a falling head permeability soakaway test.
- Six boreholes were drilled and completed with 35mm slotted standpipes to enable the ground water to be monitored.
The completed investigation concluded…
- the inadequacy of the surface drainage installation
- the presence of a high water table in the winter that would render the lateral drainage installation ineffective
- the design and installation of the soakaways were not successful
- the unsatisfactory removal of surface water was due to the texture of the topsoil and the shallow gradients – especially on pitches 5 and 6.
- the re-grading of at least pitches 5 and 6 with the creation of a camber in each pitch
- the installation of close-spaced slit drains installed with 25mm perforated piping acting as laterals
- the excavation of shallow swale soakaways adjacent all the pitches
- the development of additional shallow water storage areas
- investigation into the removal of surface water into an outfall drain in the farmer’s field to the south east
Prolonged discussion is underway to settle the dispute and initiate the remedial course of action.