The site works were undertaken in order assist in the Phase 3 Design of a strategic highway infrastructure improvement scheme to the east of the new River Wear bridge crossing. Part of the site was located within the former shipyard industrial area in Pallion before extending along the southern bank of the River Wear into the Millfield area and central Sunderland. Improvements will incorporate sections of new highway as well as widening existing carriageway routes. The scheme is intrinsically linked to the long-term economic growth of Sunderland by enhancing transportation and commercial links.
Allied Exploration & Geotechnics Limited (AEG) were contracted by City of Sunderland with Capita Real Estate and Infrastructure acting as Investigation Supervisor. The scope of the investigation was extensive comprising forty cable percussion boreholes (twenty continued by rotary open-hole/coring), thirty-two drillholes (various methods employed), seventy-eight windowless sample holes, fifteen dynamic probe holes, forty-four inspection/trial pits, cone penetration testing and other supporting services. All works were conducted under UXO specialist supervision due to the notional World War II bomb risk, as well as traffic management in road-side locations.
Key requirements during the contract were the construction of a ramp to allow access to a steep section of slope adjoining the Metro Railway line where Self-boring Pressuremeter testing was specified for a critical retaining wall structure. The ramp was proposed to reduce overall investigation costs and was an effective alternative to a slope climbing rig approach. It was a novel solution to a complex problem which otherwise would have required appreciable tree/vegetation clearance and a reliance on non-standard techniques. All the works in this area were carried out under the additional supervision of a Network Rail supervisor and the structure of the embankment could not be impinged upon by the access works. The approach ultimately passed on around £40K in savings to the Client.
Working in any urban area presents concerns; principal issues in this setting were the avoidance of underground services, minimising the impact of the investigation on traffic flow into the City and ensuring that the best interest of the public was being addressed at all times.