TOPCON: THE JEWEL IN THE CROWN OF THE KING’S CROSS REDEVELOPMENT

Managing the redevelopment of a 67-acre site is no mean feat, especially when the infrastructure on the site provides national rail services for over 100 million people a year.

The regeneration of the King’s Cross area will eventually see £500m pumped into new homes, offices, roads and improvements around the King’s Cross rail station. For over a decade, Plowman Craven, one of the largest surveying companies in the UK, has surveyed, measured and collated accurate survey information for the King’s Cross project, covering buildings, railway lines, tunnels and utilities. When it came to carefully monitoring structures near the rail station that surround a new patch of development land, the technical team turned to a tried and tested solution from Topcon Positioning.

On major developments in areas with existing infrastructure, monitoring is key to ensuring the integrity of surrounding structures and the safety of those on and around the site.

In particular, when working on piling and excavation for a new ‘landscraper’ within the King’s Cross project boundaries, Plowman Craven’s PC Monitoring division was appointed to ensure that the appropriate data was captured to provide an indication of any movement caused by the groundworks. Critical rail infrastructure exists just a few metres from the site boundary along with a particularly significant historic building. Delivering the right, near real-time data provides the assurance that the project team needs to keep these vital assets operational.

Brendon Oram, technical manager at PC Monitoring, said: “It was clear that these assets needed a comprehensive, three-dimensional monitoring approach but the complex, dynamic environment initially posed some challenges. Highly accurate data needed to be captured regularly and presented in a way that was easily understandable in order to enable timely, informed decisions regarding future works. The flexibility in Topcon’s solutions made them the perfect fit for these requirements.”

Originally, the designer’s plan for this project was to conduct manual monitoring, but PC Monitoring suggested Topcon’s Delta solutions. Brendon said: “We know we can get more consistent, and more accurate data on site thanks to Delta, without the need for regular track access. This means it is far more cost effective to capture and process the data we needed, helping to save time and money for our client.”

The PC Monitoring team had used Topcon’s Delta Monitoring hardware and software on a number of previous sites before the project at King’s Cross. While Delta Link provides hardware support for autonomous operation of total station and environmental sensor data in the field, Delta Log provides an intuitive interface to manage observations, target types and measurement scheduling. Topcon’s Delta Watch software also allows data from robotic total stations, GNSS receivers, levelling devices and a variety of geotechnical and structural sensors to be processed and analysed individually or as a network-adjusted solution, enabling easier use and analysis of various monitoring solutions.

Levi Brown, vertical construction manager at Topcon Positioning GB, said: “This is a complex project with multiple stakeholders, including Network Rail, and a number of valuable assets, including Grade II listed buildings, surrounding the works. It’s critical in situations like these to monitor assets and works closely for any unwanted movement.

“With Delta it’s possible to set up alerts that notify stakeholders of movement as necessary and enable the full team to make better informed decisions about next steps. It’s improving efficiency and quality as well as keeping the team safe on such a complex site.”

The project started in 2017 and the current phase of the project where Delta is being used will take around 36 months to complete.

Brendon said: “Technologies like this often require significant upfront investment, but it is absolutely worth it in the long term from our perspective, in terms of reducing risk. Delta is a fantastic product in the right environment; accessing live railways is dangerous and costly so we’re delighted we’ve been able to address both issues with this technology, as well as keep a very close eye on any movement that could cause issues.

“Our customers trust us because of our reliability, and we need to collect accurate and regular data to maintain that. Having used this technology previously we knew it would give us the right level of scalability, reliability and ease of use for the King’s Cross project.”