After 7 years of construction, the dam was recently completed to provide irrigation water to the surrounding districts. Holding 922 million cubic meters of water, the dam was meant to improve the agricultural output of the area and provide a source of electricity; with electricity from a hydroelectric plant to be added in the future. This breach of the 30 meter high dam led to the evacuation of nearly 100,000 people. While the exact failure mode of the early morning breach of May 1 is still unclear, the current statements seem to point to overtopping of a lower section of the dam by wind driven waves.
Forensic information from the InSAR Archive
A key strength of the Sentinel 1 and Copernicus platform is the ability to ‘go back in time’ and view the deformation of a structure with consistent over flights. Pulling a bit more than the past year of data on Sardoba showed some fascinating results. Sentinel provides some insight into the settlement of this structure over time. Recognizing that all new dam structures settle it is interesting to see rates of 100 mm per year continuing in some sections. The area of the failure did not have the greatest crest subsidence rate during this period. This failed section abuts a turn in the dam where there was significantly less subsidence in the past year. Looking closer at the settlement patterns, it seems there is noticeable differential movement along this stretch of the crest not as prevalent in others. Perhaps this played a role in the failure mode as the differential settlement could lead to weak zones or cracking. An alternative progressive slope failure mode would potentially demonstrate uplift at the toe of the embankment which was not noted in this data. However, erratic uplift and subsidence can be seen in the nearby field beneath the structure and could be a factor for consideration. We hope that this data, developed in conjunction with Ovela will be useful to Uzbek authorities in the disaster assessment and recovery process.
When a 72-inch Storm Sewer is sandwiched between a sewer and high-pressure gas lines, what could go wrong? Throw in soft ground, irregular rock surface, past litigation, interstate highway nearby, residents losing access to a major thoroughfare and you have a recipe for disaster. The designers of this pipeline project realized this and required extensive monitoring during construction. As a contractor, these are costs that don’t help you get the job done. For IMS, it was an opportunity to save the day.
Monitoring included groundwater levels, surface and subsurface settlement points, inclinometers for lateral movement detection, crack monitoring, and tilt meters on the excavation bracing system. According to the specification, all of this was to be in place before the contractor did any work in the area and was to be monitored nearly continuously while working with submission of daily data reports and alert level incident reports. Recognizing the extensive labor demands of manually monitoring such a system and the obvious staging of a linear project such as this, the automated capabilities of IMS were implemented to move a package of remotely monitored tools along with the contractor’s progress.
This remote package complimented other manual devices and allowed for installation of Measurand SAA devices in manual inclinometer tubes to measure ground deflection, electronic tiltmeters to measure tilt of the flexible SOE system, and piezometers to measure water levels as work progressed, thus obtaining the real time data continuously without the labor costs. The remote system was integrated with the sensemetric THREAD IIOT edge devices in a “portable package.” Data, alerts, and reports were shared with the owner’s representatives through Schnabel’s IMS system.
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 our Infrastructure Monitoring Service (IMS) to provide real-time access to sensor data during the deconstruction of the failed hillside, construction of a hybrid retaining wall system, and post construction performance monitoring. Leveraging both sensemetrics and Ovela monitoring platforms, IMS is delivering automated data from Measurand ShapeArrays, Geokon MPBX, Load Cells, Strain Gauges, and RST Load Cells in addition to satellite based InSAR deformation monitoring solutions to detect changes detect changes in the wall and surrounding areas of the airport.
Our IMS platform monitored:
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 construction was complete
IMS contributed to the successful construction of the project through
Analysis model verification
Data Management efficiency
Remote Access to Data
Real-time information during and after construction
Multiple sensor types feed data into the IMS platform