Objective
Project Centre provides multidisciplinary consultancy services to Kent County Council (KCC), including specialist structural consultancy support for KCC’s highway bridges and structures.
KCC commissioned us to undertake structural reviews for numerous bridges in accordance with the Design Manual for Roads and Bridges document CS 451 structural review and assessment of highway structures. The primary objective is to support KCC with managing risk and maintaining an operational highway network, including determining if any bridges require a quantitative load assessment.
Background
Kent is the one of the largest and most populous counties in the country. KCC is responsible for maintaining most of the non-trunk roads in the county, and approximately 2,800 highway bridges and structures. Their highway network is trafficked and critical to transport around and through the county.
Ensuring routes can accommodate both standard and abnormal traffic is crucial, with its structures playing a key role. Maintaining the condition and load carrying capacity of such a large number of bridges and structures presents difficult challenges. Structural reviews form a key part of highway structure asset management. These help to verify that the operational capacity aligns with the needs of the network.
Solution
Project Centre examined all relevant information, including construction drawings, previous assessments, and inspection reports. For structures with existing assessment data, the aim was to confirm whether the existing results and stated load carrying capacities were still valid. Where previous inspection data was not available, the aim was to assess the risk of failure occurring based on performance and condition history.
To ensure the structural forms were completed to a high standard, Project Centre addressed the following key questions as part of the thorough review of all available information:
- What capacity was the bridge assessed to in terms of normal (HA) and abnormal (HB) loading?
- Are the previous analysis methods used to assess the bridge capacity still valid?
- Has the condition changed significantly over time or since the last assessment?
- Has there been any change in operational requirements or load arrangements?
Following this review, Project Centre had to evaluate the outcome of these questions and the impact this had on each structure’s capacity. This included assessing the impact of condition or loading changes to specific bridge elements on previously assessed capacity utilisation ratios.
As part of this Structural Review process, we produced risk appraisal data summaries for each bridge based on its operational demands, condition, and quality of available information. This informs decision on recommending the bridge for assessment and allows KCC to prioritise further works across their asset stock.
Where applicable, Project Centre also determined modern SV capacities to help manage STGO vehicle movements. Following the review, we stated the validity of any previous assessment and the current load rating. If a new assessment was necessary, Project Centre recommended assessment parameters and bridge management actions, including if KCC should manage the structure as substandard in line with CS 470.
Value
Project Centre’s detailed and analytical review of their existing bridges and structural expertise has quantified the risk posed to network operations and user safety by their bridge stock. Our skilled and highly competent engineers have provided practical recommendations to support KCC manage their highway bridges.
This supports the ongoing operational performance of KCC’s highway structures and network. Also contributing to a reliable and safe service level for road users.
Speak to our team: Enquiries – Marston Holdings
