Case Study: Design and Performance of a 46 m High MSE WallLocation and Purpose of Retaining Wall MeasurementSeattle–Tacoma International Airport ( STIA) is located in SeaTac, Washington. This airport required expansion due to limitations in distances between existing runways due to poor weather conditions. A third runway was therefore built to the west of the two existing runways. The construction of the third runway embankment included the three MSE walls. Here are the three MSE walls: • 58-foot-high single-level south MSE wall • 85-foot-high two-level vertical north wall • 150-foot-high four-level vertical MSE wall in the west In this study , the third runway was constructed on a significant volume of compacted earth fill which was necessary to raise the level to a maximum of approximately 165 feet to reach the level of the existing runway. The west wall of the MSE was constructed to prevent creek displacement and wetland improvements were required elsewhere to compensate for the impacted wetland. The MSE west wall which is part of the western boundary of the third runway embankment. This wall construction required a four-level MSE wall approximately 1,430 feet (436 m) long and up to 150 feet (45.7 m) high. The total area of ​​the wall facade was approximately 130,200 ft2 (12,100 m2). The exposed height of the MSE wall is 137.5 feet (41.9 m). Before the construction of the MSE wall, the soil consisted of soft peat interspersed with loose to medium-dense silty sand and sandy peat. Figure 1: Aerial perspective photo of the new third STIA runway seen from the northwest and showing the north and west MSE wallsInstrumentation and measurementsThe objective of the monitoring program was to evaluate the performance of the walls for a... . middle of paper. ..... the reinforcement strips in the upper three levels showed a decrease in stress at a distance of approximately 42.7 to 68.9 feet behind the toe of the wall. And further reduction in tensile stress was also observed at a distance ranging from 95.1 to 104.9 feet behind the toe of the wall. Findings: 1. Geotechnical instrumentation, including wall surveys, inclinometer installations with Sondex settlement rings, piezometers and strain gauges on the reinforcement strips, provided the design and construction information necessary to verify wall performance against design as construction progresses.2. Natural, compacted, dense to very dense foundation soils were deposited a maximum of 4 inches or four-tenths of a percent of the height of the wall. By comparing the works cited http://www.hartcrowser.com/assets/instrumentation_and_performance_north_mse_wall.pdf