EngAnalysis is monitoring the stresses on 3 critical steel gantry structures over a rail line in Victoria.
Our client wants to manage their risk on this structure by quantifying and monitoring the bending stresses that could cause fatigue damage of the weld between the column and base plate.
The installation includes 3x full bridge strain gauges, 600mm above the critical weld, providing temperature compensated bending and torsional stress. Data is logged and transmitted through an LTE modem to the EngAnalysis data center in Newcastle where it is processed and transmitted to a real-time portal.
The hardware setup was customized by the EngAnalysis team to suit the monitoring requirements for the structure. The system logs high frequency data and our analysis package processes the data and transforms the peak readings into 20 minute segments where it is available on our near real time visualization portal.
The portal allows our client to log in and access a near real and time history analysis of the structural stresses and also provides automatic alerting if stresses exceed a defined threshold. EngAnalysis also provide a monthly report, which includes further data analysis and predictive forecasting, taking into account the number of cycles within various stress ranges.
Our analysis also incorporates local weather by correlating peak stresses with measured wind speed. This methodology has given verification to the stresses we see and allowed us to identify and omit erroneous data, such as a period when some maintenance upgrades were being performed on the structure.
Through ongoing and real time monitoring, the project has enabled our client to mitigate their “risk of the unknown” by providing key risk indicators (stress amplitude) for the monitored structures, as well as providing a contextual data set that may be used for understanding their broader risk of similar structures across the network.
Following floods in 2021 in NSW, a program of underwater bridge inspections took place. This bridge was identified as having defects and was immediately closed to traffic, isolating a community.
EngAnalysis were engaged at short notice to provide an end to end turn key monitoring solution. The bridge engineer specified a requirement for a series of tilt meters on multiple piers. The tilt meters would initially be used to refine an FEA model of the bridge by helping define longitudinal and transverse stiffness which would become an input into assumptions for material properties and boundary conditions.
The bridge then underwent a series of progressive load tests and data was used to monitor and verify the results of load tests, and to confirm that no adverse effects were experienced at critical locations. This was a fantastic collaboration between client, engineering consultant and EngAnalysis where assumptions were validated and performance verified through data driven engineering.
The load tests were successful and the bridge was opened up to traffic. To enable opening and to provide ongoing risk indicators, EngAnalysis has continued to provide monitoring as a service. Our real time data which is accessible through our portal provides up to date tilt readings on the critical elements. If the tilt readings were to exceed predefined thresholds, an alert would be generated, triggering an immediate investigation.
This methodology allows the asset operator to open the bridge to traffic whilst repair works are planned and undertaken, all the while managing the risk to the community. This monitoring program is an excellent example of the value ad for structural health monitoring and risk indicator monitoring. What is the value of being able to maintain the bridge open to traffic? What is the value in engineers and the community being able to continue with their daily tasks, knowing the risk is being managed? These are hard to define, although we suspect the value is many times the cost of the monitoring program.
EngAnalysis was recently approached, asking if it would be possible to automate the monitoring of a 110yo bridge abutment that was experiencing major ground consolidation during the build of a replacement duplication bridge. The project requirements were to supply the half hourly displacements of the abutment over a 24hr period on a daily basis.
The current monitoring methods proved expensive, inconsistent and lacked easily digested reporting and trending. We took an agnostic approach to the technology used, by augmenting traditional monitoring methods. Enganalysis proposed permanently installing an S9 Trimble Total Station, recording target locations on a half hour basis with automated reporting and alarming using a combination custom data portal backed by MATLAB scripts and twice daily automated emailing of 24 hour displacements and project lifetime trending.
The onsite system was installed within days from purchase order/ first contact, with semi-automated reporting arriving in our client’s inbox within 7 days. Full automation was progressively implemented with displacement reports, long term trend plots and alarm reporting emailed twice daily, as an end result.
We are proud of this project because a number of long-term benefits expanded client’s radar of technology options. Previous manual 24-hour reporting did not allow for metered reactions, and made decisions and workflow volatile. Customer feedback was extremely positive, with statements such as “The data was very easy to follow and gave me confidence to not complete repairs that previous conservative models would have demanded”, and “This project has opened my eyes to many other possibilities and ways to improve our structural asset management using models based on real data”.
The Pressure Tunnel is one of two primary water supplies for the Sydney Metro area, its construction was completed in 1935 and is considered of high historical and technical significance. The construction of two Metro tunnels and the WestConnex all pass within close proximity to the Pressure tunnel. EngAnalysis developed, deployed and maintain a Structural Health Monitoring System for the Pressure Tunnel pipeline a critical asset in the supply of water to Sydney.
This system comprises of over 220 HBM fiber Bragg optical strain gauges as well as pressure and temperature sensors, all reporting into multiple bespoke real-time data analytics portals for Sydney Water and their stakeholders.
EngAnalysis pre-assembled much of the system allowing for a fully installed in the Pressure Tunnel during 4 days of access.
