Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

Two separate deep-seated, creeping landslides exist in close proximity in a mountainous area with highly heterogeneous geological and geotechnical conditions. The ground movements are measured at a depth greater than 50m and affect 65m-high G4 embankment and 240m-long S3 tunnel that are under traffic since 2004. The first landslide affecting the embankment initiated shortly after completion of construction in an area where the highway was realigned after an old, pre-existing unstable area was identified during the design. Tunnel S3, about 300m to the east of embankment G4, suffered from slope instability during construction. This was successfully dealt with and the tunnel was completed without any further problems. Yet, a number of deep inclinometers that were installed to monitor post-construction performance revealed the presence of deep seated, creeping movements affecting the entire tunnel. Due to the curvature of the alignment, both slip surfaces daylight in the same area at the bottom of the valley downhill. The stabilization measures involve the construction of a single toe berm, approximately 700,000m3 in volume, which extends across the bottom of the valley and provides stabilization to both areas.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 4th, 12:00 AM

Highway Section Affected by Two Neighboring Landslides – Performance, Monitoring and Design of Stabilization Measures

Chicago, Illinois

Two separate deep-seated, creeping landslides exist in close proximity in a mountainous area with highly heterogeneous geological and geotechnical conditions. The ground movements are measured at a depth greater than 50m and affect 65m-high G4 embankment and 240m-long S3 tunnel that are under traffic since 2004. The first landslide affecting the embankment initiated shortly after completion of construction in an area where the highway was realigned after an old, pre-existing unstable area was identified during the design. Tunnel S3, about 300m to the east of embankment G4, suffered from slope instability during construction. This was successfully dealt with and the tunnel was completed without any further problems. Yet, a number of deep inclinometers that were installed to monitor post-construction performance revealed the presence of deep seated, creeping movements affecting the entire tunnel. Due to the curvature of the alignment, both slip surfaces daylight in the same area at the bottom of the valley downhill. The stabilization measures involve the construction of a single toe berm, approximately 700,000m3 in volume, which extends across the bottom of the valley and provides stabilization to both areas.