Automated Monitoring Network for LUAS tramway at Naas Road and Kylemore Road Junction – Dublin, Ireland

Client
> New Century Engineering, working on behalf of Transport Infrastructure Ireland (TII)

Sector/Market
> Infrastructure

Services
> Monitoring – Ground Movement, Monitoring – Asset Performance

Location
> Dublin, Ireland

Project summary

Due to the installation of a 110kV electricity power cable from Inchicore to the Airton Substation, a Horizontal Directional Drilling (HDD) dig was required to allow for two ducts perpendicular to the LUAS red line. The proposed HDD dig took place at the junction of the Naas Road and Kylemore Road, west of Dublin city. The works had the potential to cause both vibration and ground movements along Luas infrastructure at this junction. Murphy Surveys were engaged by New Century Engineering to provide a continuous real time monitoring solution for movement and vibration to mm accuracy 24/7 during the works.

The challenges

The LUAS railway line was embedded and therefore no instrumentation (Prisms) could be installed directly to the rail. Another challenge was that this junction is an extremely busy junction. Mitigating against false readings caused by traffic was a large factor.

Our work

The works included the establishing of accessible locations for monitoring, the installation of monitoring equipment and the carrying out of monitoring works as well as processing and alarming. All operations will be conducted in a safe and efficient manner following HSA regulations and Murphy Surveys Health & Safety policies and procedures.

After a consultation with the system manufactures and experts from Leica, Murphy Surveys specify that 1 AMS system was required to cover the approx. 60m of Luas track that requiring monitoring. A single AMS system is based on erecting the AMS system on a 3-metre monitoring pillar. Murphy Surveys will also implement Precise Levelling to add an extra layer of redundancy to the monitoring system. We also used vibration sensors at key locations to ensure vibrations do not exceed the agreed trigger levels during the HDD dig.

Results

All monitoring data from all instrumentation was sent via cellular network to a central database based in our offices and uploaded to GeoMoS NOW! for viewing by all parties. Website credentials and training was provided on the use of the website in order to view results from the data, which was presented in graphical format. Leica GeoMoS software provides a highly flexible automatic deformation monitoring system that can combine geodetic, geotechnical and meteorological sensors to match the needs of any monitoring project. With the addition of the GeoMoS Web service, visualisation and analysis of monitoring data can be performed anywhere and anytime using a web browser, mobile phone or tablet allowing for informed decisions.

All data was analysed for any breached trigger levels by means of trend analysis. Our teams set trigger levels to allow for notification of any potential trigger breaches. The potential for there to be false readings due to site conditions, weather, disturbed equipment etc was considered. The clients alarming procedures were followed regarding the alerts.

Our teams implemented construction and non-construction hours for alarming. We saw it to be more practical to have only the teams ‘on-call’ during the weekends and nights on the alarming system and then in the event of a trigger occurring they may respond and address the alert immediately and have a report ready for the client the following morning. In the possible event of a red trigger value occurring in non-construction hours and having being confirmed on site then contact would be made with the client immediately.

Contact

For more information on this project, please email info@murphygs.ie or call us on +353 (0)1 690 9799