By March 10 th, engineers were on site to investigate. Initial investigation was later expanded due to the slopes progression and by 2015 borings were done to obtain soil and rock samples and to install piezometers and inclinometers.īy Feb 2015, the crest of the RSS had settled 23cm and appeared to be increasing in movement. A tension crack was also observed at the back of the RSS zone, suggesting a slip surface was developing. The sloughing was determined to be located in the external rock-clay mixture which didn’t significantly change the slope’s geometry. Mostly cobble and boulder-sized sandstone shotrock.įrom its completion in 2006, there were no observable changes until 2013 when minor surface sloughing occurred near the base of the RSS. Retained Fill – Outside the perimeter of RSS.Clay was incorporated near face to provide a soil medium for vegetation to grow on the slope face. General Fill – Mainly clean sandstone shotrock.Select Fill – Sandstone (max particle size of 0.15m).Three categories of fill material were used: Reinforced panel lengths ranged between 8m and 53m with a length to slope height ratio of 0.70 or greater and two woven polyester geogrids, Mirafi 10XT and 20XT were selected. Prior to construction, LE analysis was conducted to analyze the design of the RSS.ĭuring construction, the lower third of the RSS had vertical spacing of 46 cm and above that, vertical spacing increased to 91cm. The area to the north east was where the fill material would be gathered from. Construction started in August of 2005 and was finished by December of 2006.Ģ9 soil boreholes were taken from the area of construction and 8 borings to the north east. Due to the terrain and high elevation of the airport, a RSS was needed to be able to extend the runway. To comply with updated Federal Aviation Administration design requirements, Runway 5 of the Yeager Airport needed to be extended in length by approximately 160 meters. The purpose was to not only to identify the cause of the failure but also to determine if the failure could be accurately predicted with Limit Equilibrium (LE) analysis using the original design plans, pre-failure analysis and the samples collected from the post-failure site. On March 12 th, 2015 a catastrophic failure of a 73-meter tall, reinforced soil structure (RSS) occurred at the end of Runway 5 of the Yeager Airport in Charleston, West Virginia, only 8 years after it was constructed.Įngineers were brought in for a post-failure investigation to determine the cause of this failure.

Rocscience slide crack