Overview: Through the commitment and vision of the customer appointing Utility Results who worked closely with contractors and Highway Authority. An extremely complex infrastructure construction project was undertaken with all available information to minimise the impact to environment, traffic, cost and programme.
The initial fundamental task was to investigate the feasibility of providing a service supply from the UKPN 132kv Grid Primary Substation to a newly constructed 132KV/11KV privately owned primary substation situated at the customers site.
Feasibility Study
This study included the fulfilment of the following evaluations:
Possible alternative routes
Identifying and mapping of existing 3rd party infrastructure in the highway
Proving and mapping of feasible construction route
Traffic management requirements
Environmental
Reinstatement criteria through core sampling
The project was undertaken in two phases:
Phase 1: This phase investigated the traffic, environmental and engineering impact on a number of possible routes, utilising route video and detailed onsite inspections, along with available information on structures, third party utility infrastructure and land ownership.
Phase 2: It was essential that the information ascertained in the phase 1 investigation was confirmed. There were a number of options open to the project team and it was decided to utilise all available technology, each of which can are highlighted below.
Third Party Utility Infrastructure
Utilising available 3rd party utility infrastructure records and traditional plant location technology it was possible to confirm and map their position.
Proving of Feasible Construction Route
Traditional methodology could have meant the excavations of trial holes every 200m, but it was decided to utilise the latest technology of ground penetrating radar, balanced with the mapped 3rd party utility infrastructure, to identify a feasible route.
Traffic Management
Once the construction route had been identified it was possible to ascertain the traffic management requirements needed to minimise disruption during the construction. This was undertaken utilising a video of the route, on site investigations, and detailed liaison with representatives from the Surrey County Council Highways team and Surrey Police.
Environmental
Although it may have been feasible to place sections of the route in the verges or footway, it was decided that due to the high number of trees along the route and to comply with the NJUG’s guidelines on the planning, installation and maintenance of utility apparatus in proximity to trees, the majority of the construction would need to be undertaken in the carriageway.
Reinstatement Criteria
To facilitate a full understanding of the potential impact on traffic, it was originally proposed that all streets be trial holed to ascertain the reinstatement criteria. This traditional methodology was going to result in scheduling, noticing and traffic management implications, so it was decided to utilise core sampling as an alternative.
Through the forward thinking and the technical foresight of Utility Results with the support and understanding of Surrey County Council, this planning feasibility survey enabled all parties to understand and manage the impact of the construction phase.
