Project

GEO-Instruments survey teams are providing a composite monitoring scheme for Network Rail mainline tracks influenced by an active landslip.

As ground reinforcement works are underway by colleagues in Keller, 500 metres of dual track requires thorough monitoring for potential movement.

GEO-Instruments Track Monitoring Trolley Survey
A GEO-Instruments team conducting a track geometry survey during engineering hours as tamping works take place on the opposite track.

As ground reinforcement works are underway by colleagues in Keller, 500 metres of dual track affected by the landslip requires thorough monitoring for potential movement.
GEO-Instruments engineers have installed over 700 specialised 3D prisms onto the tracks which are read by six networked Automated Total Stations (ATS). 
This solution allows for high accuracy, regular readings 24 hours a day. 

Monitoring prisms are also installed on OLE stanchions and a nearby road bridge that passes over the monitored area of track.

Train services remain uninterrupted throughout the works, so most surveys, installations, and maintenance need to take place during track possessions in engineering hours.
In some cases, maintenance can be carried out away from the track during running hours.

Regular tamping is taking place on this section of the line which noticeably changes the position of the rails and the measured location of the prisms. Tamping also occasionally moves or damages individual prisms, requiring nightshift maintenance visits to adjust or replace prisms.

GEO-Instruments Track Monitoring Train

The ATS network provides 24-hour 3D track monitoring while train services can continue uninterrupted.

In order to establish a baseline to compare with measured differential movements, detailed track geometry surveys were carried out before the installation of the ATS and prism network.
These surveys are performed using a Track Trolley and Total Station to accurately measure the profile of the rails. 
Cant, twist and lateral movement of the tracks is calculated automatically in QuickView, GEO-Instruments’ browser-based monitoring software. 

QuickView is also being used to produce and distribute regular, automated monitoring reports to clients and contractors, helping to keep relevant parties informed.

GEO-Instruments Track Monitoring ATS

The ATSs are protected from the weather by customised cages that allow unobstructed line of sight to target prisms.

GEO-Instruments Track Monitoring Prisms

Specialised track prisms (seen here in orange) are installed at regular intervals on each rail without affecting the passage of trains.

Keller are undertaking part of the necessary reinforcement works to stabilise the ground around the line by installing piles. Other reinforcement works include widening the embankment, and improving groundwater drainage.

GEO-Instruments are bringing years of extensive expertise and experience to this complex project. Learn more about our other railway monitoring schemes.