On March 12, 2015, a 240-ft tall slope failure destroyed the Engineered Material Arresting System (EMAS) Runway 5 at Yeager Airport in Charleston, West Virginia.

In response to safety concerns, Schnabel Engineering deployed the Infrastructure Management System (IMS) to provide realtime access to sensor data during the deconstruction of the failed hillside, construction of a hybrid retaining wall system, and post-construction.

Composed of both sensemetrics and EO59 monitoring platforms, IMS is delivering automated data from Measurand ShapeArrays, Geokon MPBX, Load Cells, and Strain Gauges, and RST Load Cells in addition to satellite based InSAR deformation montoring solutions to detect changes in conditions during construction activities and post construction performance monitoring. 

Using these tools, IMS was able to monitor:

• Deflection of the soldier pile during backfilling and anchor tensioning using SAA sensors

• Settlement of the backfill zone using MPBX sensors

• Load carried by tiebacks restraining the lower wall using Load Cell Sensors

• Strain on the tie rods restraining the upper wall posts using Strain Gauges

• Ground deformation of the project site using InSAR

•  Long term performance of the hybrid retaining wall system after the completion of the Runway Safety Area (RSA) reconstruction

Schnabel's IMS platform was able to deliver many benefits that contributed to the successful construction of the project:

• Reduce Risk

• Analysis model verification

• Data Management efficiency

• Remote Access to Data

• Real-time information during and after construction

• Automated Alerting

However, the new backfill and wall at the end of Runway 5 only comprise a small piece of the airport’s property. Construction of the airport required significant earthwork to level the mountainous areas.  The naturally weathering rock formations combined with over nine million cubic yards of moved earth and rock lead to a property with steep slopes and some settlement concerns.

While specialized instruments such as those installed during the reconstruction of the RW5 RSA can provide valuable information about ground movements around the new wall, it is not economically feasible to monitor the entire property in this manner. 

Reviewing InSAR data from both naturally reflective locations as well as reflectors installed in areas of particular interest that lack sufficient natural reflectivity can provide insight into areas of concern.  Conversely, it can provide insight into areas that should be of concern that may not be otherwise noticed until significant distress occurs. Monitoring in this manner allows the Airport administration to be proactive rather than reactive to potential ground movement issues.

Based on the observed trends, airport maintenance can keep a watchful eye on areas identified as problematic. While no amount of monitoring will predict sudden changes, this data allows identification of developing trends in hopes of mitigating gradually developing issues before they become disruptive to airport operations and the surrounding community.

Our guest author
Johanna Mikitka Simon

Johanna is a Schnabel Project Engineer with a history of working in the geotechnical/geo-structural engineering industry. Skilled in Geotechnics, Instrumentation, Support of Excavation Design, Foundation Design, and AutoCAD. She is a strong engineering professional with a Master of Science (MS) focused in Geotechnical Engineering from Drexel University.