Seal Sands & Port Clarence: Abnormal Load Geotechnical Assessment
Assessing carriageway capacity, ground settlement and buried-culvert risks along a 6 km industrial transport route in Teesside.
- Geotechnical Engineering
- Highway & Pavement Assessment
- Settlement & Load Transfer Analysis
Project Overview
Engineering assessment for the movement of a 700-tonne abnormal load across a 6 km industrial highway route in Teesside.
Stockton Borough Council commissioned Northpoint's Geotechnical Engineering Team to assess whether the existing carriageway and underlying ground could accommodate the proposed movement between Wilton Engineering at Port Clarence and ConocoPhillips at Seal Sands.
Middlesbrough Council's Laboratory Services completed the intrusive ground investigation along the route. Northpoint's role was to interpret the investigation data, assess the response of the pavement and ground to the proposed live loading, and identify locations where protective measures were required.
Client Requirements and Challenges
The proposed movement introduced exceptional temporary loading across a route, rather than at a single prepared working area. The evidence therefore had to account for changes in carriageway construction, sub-base and underlying soils over approximately 6 km.
The route also crossed buried services, pipes and culverts. These features could respond differently from the surrounding carriageway, so a conclusion based only on general pavement condition would not provide the highway authority with the location-specific assurance it needed.
The client required clear answers to three practical questions: whether the existing carriageway construction was adequate; how much settlement could occur as the abnormal live load was transferred into the ground; and where local measures were needed to protect buried structures.
Our Approach and Methodology
Northpoint reviewed the available evidence from the intrusive ground investigation completed along the route. This included a visual assessment of the highway condition, road cores, details of the pavement construction layers and boreholes extending into the natural ground.
This information was considered alongside the proposed transport arrangement and abnormal live loading. The assessment examined the capacity of the existing carriageway before evaluating the potential settlement of the underlying ground as the wheel loads were transferred through the pavement.
By assessing the complete route, Northpoint could distinguish between the general response of the carriageway and the more sensitive local conditions associated with buried infrastructure.
Particular attention was given to the brick culvert crossings, where the way the load transferred through the carriageway required a different engineering approach from the surrounding sections of road.
Results and Deliverables
Northpoint's detailed geotechnical assessment and calculations concluded that the existing carriageway construction and underlying ground conditions were generally adequate for the proposed loading.
The assessment also identified an important local exception. Where the route crossed brick culvert structures, Northpoint recommended overbridging the load so that it would not impose a significant effect on the sub-structure features.
The deliverable therefore did more than provide a route-wide pass-or-fail conclusion. It separated the sections supported by the existing road and ground conditions from the specific locations requiring local protection, giving the highway authority a clear technical basis for abnormal-load route and protection planning.
Supporting Abnormal and Heavy-Load Movements
Northpoint supports highway authorities, transport planners, asset owners and contractors with geotechnical assessment for abnormal-load movements, heavy plant and other concentrated temporary loads. Our engineers interpret ground investigation and pavement data, assess settlement and load transfer, and define proportionate measures for sensitive structures and variable ground.
Planning an abnormal or heavy-load movement?
Northpoint can assess carriageway capacity, ground settlement and risks to buried structures, providing the technical evidence needed to plan your route with confidence.