MITIGATING RISKS TO ESTABLISH SAFER GROUND
Case studies
Cardiff Arena Redevelopment
Client: Multiple Contractors (Tier 1 Supply Chain)
Location: Cardiff, South Wales
Development: Arena redevelopment and deep foundation works
Intrusive Works: UXO watching briefs (remediation phase), pre-drilling, CPT intrusive surveys, piling, ground investigation
RECCE-SI was engaged across multiple phases of the Cardiff Arena redevelopment, providing UXO risk mitigation support to various contractors operating on the scheme. The site, located within Cardiff’s historic docklands, was subject to significant WWII bombing, with made ground depths of approximately 4m to 9m increasing the potential for deeper bomb penetration. During the remediation phase, RECCE-SI delivered a series of UXO watching briefs to support bulk earthworks and material processing. This was followed by a programme of pre-drilling and CPT intrusive magnetometer surveys to mitigate UXO risk for piling operations, achieving targeted clearance to the required depths in line with CIRIA C681 and Maximum Bomb Penetration Depth (MBPD) principles.
Outcome:
- Pile locations cleared to ALARP in accordance with CIRIA C681
- No UXO anomalies identified
- Piling works completed without delay
- Seamless transition from remediation phase to intrusive foundation works
- Supported multiple contractors across a major development
Surrey Quays Redevelopment
Client: Erith (Principal Contractor)
Location: Surrey Quays Road, London
Development: Post-demolition remediation and groundworks
Intrusive Works: Bulk excavation, remediation, pile removal, pre-drilling, CPT intrusive surveys (crane base clearance)
RECCE-SI provided a UXO watching brief during post-demolition excavation works at a high-risk London site with known WWII bombing history. Support was delivered across multiple phases between 2024 and 2025, with repeated mobilisation as the project progressed. Continuous monitoring ensured safe excavation across multiple structures and work areas.
In addition to the watching brief, RECCE-SI undertook pre-drilling and CPT intrusive magnetometer surveys to facilitate UXO risk mitigation for crane base locations. These works enabled targeted, depth-specific clearance in line with anticipated loading requirements, ensuring safe crane installation within the development footprint.
Outcome:
- All excavation areas cleared to 3.0m BGL
- Crane base locations risk mitigated through intrusive CPT surveys and pre-drilling support
- No UXO identified across all phases
- Works completed safely over an extended programme
- RECCE-SI retained for multiple project phases
Brighton & Hove Bus Depot
Client: Site Analytical Services Limited
Location: Conway Street, Hove
Development: Bus depot redevelopment and foundation works
Intrusive Works: Piling, CPT intrusive surveys, pre-drilling, trial pit excavations, window sample boreholes
RECCE-SI undertook an intrusive UXO magnetometer survey to support piling works within an area of potential UXO risk.
In addition to the piling support, a programme of trial pit excavations and window sample boreholes was carried out to characterise ground conditions and inform construction design. These works were integrated with UXO risk mitigation measures to ensure safe intrusive investigation across the site.
Using CPT magnetometer technology supported by pre-drilling, RECCE-SI delivered efficient area-based clearance while facilitating the wider ground investigation scope.
Outcome:
- 98 pile locations assessed and risk mitigated
- Trial pits and window sample boreholes successfully completed to inform ground model and design parameters
- No UXO anomalies identified
- Piling and site investigation works progressed without delay
- Efficient coverage achieved through optimised survey design
Rail Infrastructure Project
Client: Confidential (Rail Sector Contractor)
Location: London
Development: Rail infrastructure and ground investigation works
Intrusive Works: Borehole drilling, excavation, site investigation
RECCE-SI provides ongoing UXO support for a rail infrastructure project, delivering both watching brief and borehole support services across multiple phases.
Works are carried out within a live rail environment, requiring a flexible and responsive approach to meet programme demands.
Outcome:
- Multiple phases delivered safely within a live rail environment
- No UXO-related delays or incidents
- Ongoing support reflecting strong client confidence
- Seamless integration with drilling and site teams