Location
Chicago, Illinois
Date
02 May 2013, 4:00 pm - 6:00 pm
Abstract
In the winter of 2010, a landslide occurred on Egnatia motorway affecting an embankment approximately 300m long and 8–20 m high. The crest of the slide was at a distance of 60m uphill from the highway and the maximum depth of movement was 28 m. The bedrock in the area consists of alternating layers of siltstone and sandstone with local conglomerate intercalations covered by a soil layer of variable thickness (up to 30m) and consistency. The sliding occurred within a zone of plastic red clay just above bedrock exhibiting strength parameters between peak and residual values. A horizontal movement of 30cm was recorded with an initial rate of up to 15mm/day measured in the numerous inclinometers that were installed. Immediate measures were adopted consisting of dewatering through pumping wells constructed in the central reserve between the two carriageways and unloading through earth removal from the crest of the sliding mass. These measures resulted in a significant mitigation of the movement allowing for the design and construction of permanent stabilizing measures (mainly shear keys) whilst the motorway remained under continuous operation. A staged approach was applied in the design and construction of the remedial works based on the constant monitoring of the slide behavior through inclinometers. The paper describes the sliding event and the actions taken to deal with the emergency. It presents the geotechnical model and the geometry of the sliding based on the results of the geotechnical investigation and the extensive network of instruments that were installed. It discusses the alternatives examined and the stabilization measures that were designed and eventually implemented. Finally, it outlines the construction sequence and assesses the effectiveness of the stabilization measures to date based on the geotechnical instrument monitoring.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
7th Conference of the International Conference on Case Histories in Geotechnical Engineering
Publisher
Missouri University of Science and Technology
Document Version
Final Version
Rights
© 2013 Missouri University of Science and Technology, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Sakoumpenta, Eleni; Houssiadas, Vassilis; and Haralambakis, Manolis, "Stabilizing a Landslide on a Highway Under Traffic: A Case History on Egnatia Motorway in Greece" (2013). International Conference on Case Histories in Geotechnical Engineering. 77.
https://scholarsmine.mst.edu/icchge/7icchge/session03/77
Stabilizing a Landslide on a Highway Under Traffic: A Case History on Egnatia Motorway in Greece
Chicago, Illinois
In the winter of 2010, a landslide occurred on Egnatia motorway affecting an embankment approximately 300m long and 8–20 m high. The crest of the slide was at a distance of 60m uphill from the highway and the maximum depth of movement was 28 m. The bedrock in the area consists of alternating layers of siltstone and sandstone with local conglomerate intercalations covered by a soil layer of variable thickness (up to 30m) and consistency. The sliding occurred within a zone of plastic red clay just above bedrock exhibiting strength parameters between peak and residual values. A horizontal movement of 30cm was recorded with an initial rate of up to 15mm/day measured in the numerous inclinometers that were installed. Immediate measures were adopted consisting of dewatering through pumping wells constructed in the central reserve between the two carriageways and unloading through earth removal from the crest of the sliding mass. These measures resulted in a significant mitigation of the movement allowing for the design and construction of permanent stabilizing measures (mainly shear keys) whilst the motorway remained under continuous operation. A staged approach was applied in the design and construction of the remedial works based on the constant monitoring of the slide behavior through inclinometers. The paper describes the sliding event and the actions taken to deal with the emergency. It presents the geotechnical model and the geometry of the sliding based on the results of the geotechnical investigation and the extensive network of instruments that were installed. It discusses the alternatives examined and the stabilization measures that were designed and eventually implemented. Finally, it outlines the construction sequence and assesses the effectiveness of the stabilization measures to date based on the geotechnical instrument monitoring.
