Cherry Park DLR Monitoring, UK

Client
> Westfield Europe

Sector
>Infrastructure

Sub Sector
>Light Rail

Services
>Monitoring - Structural Health
> Rail Surveys

Solution
>Track Survey
> Asset Monitoring
> Gauging

Location
> Stratford, East London, UK

Project summary

The Cherry Park development consists of seven new residential buildings, a Retail Box, and a basement. With buildings extending up to 38 storeys with a basement that extends across the entire site footprint. The Cherry Park development will border the southern portion of the ‘Phase 1’ section of the DLR box. The foundation piles and the Retail Box will intersect the Woolwich Line Enclosure influence zone, which is defined as the area that falls within a 45-degree line drawn from the upper corners of the Woolwich Line Enclosure.

The brief

To install, commission and maintain an autonomous structural monitoring system adjacent to the Cherry Park Development in Stratford, East London to ensure safety and certainty to the client and asset owner, Transport for London, during the construction programme. The potentially affected assets consisted of two running lines on the DLR train network, the Woolwich Tunnel Enclosure and surrounding platform structures over a length of 300 metres.

The challenges

To comply with TFL standards, no construction activity on site could commence without a 90-day continuous set of data, where unmanageable background movement could be analysed and assessed, otherwise known as the baseline period. To ensure the overall construction programme was not affected, Murphy Geospatial mobilised to site and installed the system within 10 working shifts, where access can only be achieved within small windows during track isolation periods. After the 10 shifts, not only was the system fully installed, but the database was also set up and the monitoring baseline had begun.

Our work

Murphy Geospatial commissioned the following automated system to ensure the tunnel, platform
structures and rail infrastructure were monitored accordingly where mitigation actions could be taken if
required, measuring highly accurate, absolute, and relative movement.

• 3 no. Total Stations and associated communication equipment.
• +250 no. Geodetic track mounted survey prisms.
• +120 no. Geodetic low profile platform survey prisms.
• +20 no. Geodetic tunnel survey prisms.
• +12 no. Geodetic common reference survey prisms installed outside the zone of influence.

All data was collated and viewed through an online web portal via graphical and tabulated displays where trends could be analysed. From the measured movement, additional real-time calculations were set up to measure track geometry and platform clearance.

In addition, Murphy Geospatial completed a comprehensive control network, rail and platform geometry surveys and a photographic condition assessment. The solution provided geospatial certainty to our client and the asset owner during the lifecycle of the construction project.

Our team

One of our experienced project managers, oversaw the project from start to finish, including on site supervision, delivery of all data and direct liaison with all parties involved. The engineering team installed and commissioned the automated system, along with our surveyors implementing the control, network coordination and all required pre-install geometry surveys. This gave us the detailed information required, ensuring that we gave vital support to all involved during the project.

Results

The measured data was viewed via an online portal and summarised within a fortnightly report where additional data calculations were setup within the database to comply with rail monitoring standards. The following outputs could be viewed within the portal, in real-time, and via the summary reports:

• Absolute and relative coordinate changes determining corresponding movement from the initial
baseline coordinate.
• Track cross-fall calculations to determine track CANT displacements.
• Track twist calculations, determined by the CANT or cross-fall.
• Track gauge calculations between the running rails.
• Platform clearance calculations between the nearest running rail and platform edge.

If a trigger was breached or a critical event occurred, all parties would be notified immediately via SMS and
email, where an engineering review meeting could be setup immediately

Testimonial

The success of this project underlines our reputation in delivering services to equip our clients with the data and information they need to make decisions at every stage. We draw on the experience and skills of our people to deliver certainty our clients can trust.

Contact

For more information on this project, please email our UK Monitoring team info@murphygs.com or call us on +44 (0)192 362 4800