Value: £600,000

Client: Stockport Metropolitan Borough Council

Start Date: January 2019 

Finish Date: July 2019 

The Astley Street project provided a new highway link across a new bridge over the River Mersey (built by others).  The new link connected Heaton Lane / A6 to the Bus Interchange and Chestergate, in advance of a major re-development of the area. The link enables buses to ac-cess a temporary bus interchange at Heaton Lane, during re-development of the existing bus station. This meant that that the link would quickly become a highly trafficked route and so delivery was time and quality-critical.  The project was procured under the Stockport Frame-work Contract as part of the TfGM funded TCAP Scheme.

The construction of the link road involved the widening of the existing 3m wide sub-standard carriageway to a 12m road, footway and lay-by and consisted of:-
  • Bulk excavation and cellar area treatment  
  • Drainage attenuation (crated and oversized pipes)  
  • Carriageway and footway construction
  • New car park
  • Traffic signal-controlled junction
  • Pelican crossing
  • Landscape and fencing
  • Utility diversion
  • Lighting and signage

We were brought in at design stage to help Stockport Council come up with a way of building a road over the river Mersey. Our preliminary investigation works used drone technology to survey and photograph the whole site, including the river embankment.

During these preliminary investigations, we determined that the construction of the new road would involve the excavation and back filling of existing cellars (up to 3m underground) to provide stable foundations.

The original budget for this scheme did not include for any of these works. Therefore, we provided Stockport with an accurate budget figure to include all the additional elements thrown up due to the investigation works. this meant the scheme had to be redesigned and we undertook a value engineering exercise to look where cost savings could be made. 
In collaboration with Stockport Council we agreed that arisings from the bridge construction would be used as the backfill material. This meant that we had to exhaustively test the material to ensure that it would meet the standards in the Design Manual for Roads and Bridges. 

The bridge was to be constructed by others under a separate contract immediately prior to our works. This caused complications at the beginning of our programme as the bridge contractors over ran on their programme, causing delays from the very start. We adapted our programme so we could start sections of our work that would not interfere with the bridge construction. This meant that our site was affectively split in two whilst we worked on both sides of the bridge, unable to cross until it was fully constructed. This inconvenience greatly impacted on the efficiency of our normal working day and incurred extra cost, which we absorbed to ensure that the delays would not impact the overall end date of the project. Our collaborative approach and agility ensured that all works would be completed on time. Following the completion of our works, we were asked by Stockport Council to undertake remedial works on the bridge that included expansion joints and concrete structural works. 
As the construction site was adjacent to the existing bus station, we maintained close, regular liaison with the TfGM and Stockport Council Highways Department at all times. This mitigated the impact of the project on bus station operations and minimised traffic congestion.

Daily liaison with the surrounding businesses was also essential to the smooth running of the project. As the works were to be fenced off to the general public, we decided to install a coded lock system to ensure that stakeholders could still access their properties when necessary. In addition to this, we built a small haul road to allow local businesses safe access to their properties. We also proposed the installation of additional steps to fire exit adjacent to the site, as the levels of the foot-paths dropped quite dramatically, making it unsafe to use as an exit. 

Throughout the project we made a number of efficiency and value engineering proposals which maintained the high-quality standards set by Stockport Council. These included, using plastic pipes as a cheaper, safer alternative, to concrete. We also recommended that instead of an Aco Drain, we use a normal gully with a side entrance, which were a much more readily available and cheaper option. These alternative materials were also easier to install, meaning the works could progress quicker.

Prior to the drainage being installed, some further investigations work had to be carried out in order to find the existing discharge point as there was no record of this. Our investigation revealed that the pipes were also blocked further downstream the pipe. Therefore, further cleaning work was required before the discharge point could be located. Without this investigation work, the new drainage system would have immediately failed to operate correctly. We located the discharge point and installed oversized pipes and attenuation system in the new car parking area to deal with storm water flows. 

Due to the site location, some environmental factors had to be considered. These including bank protection works to protect the river and our own workforce. During construction, a nearby factory was emitting smoke of an unknown substance. We had concerns regarding our workers, as they could be inhaling harmful substances. Precautionary measures were taken on site and the Environmental Agency was contacted to resolve the issue. 

Despite the unforeseen delays, which lay outside our control the project was delivered on time and has since become a main route for the buses accessing the bus station. The scheme received a great response from local residents and the bus drivers stating that it has greatly helped ac-cess around the town.