Document Type

Article

Publication Date

8-27-2018

Department

Department of Geological and Mining Engineering and Sciences

Abstract

The Enguri dam and water reservoir, nested in southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that involve a subaerial area of 1.2 km2. The head scarp interests the main Jvari-Khaishi-Mestia road with offset of man-made features that indicate slip rates of 2-9 cm/y. Static, pseudostatic and Newmark numerical analyses, based on field and seismological data, suggest different unstable rock volumes basing on the environment conditions. An important effect of variation of water table is showed, as well as the possible destabilization of the landslide following seismic shaking compatible with the expected local Peak Ground Acceleration. This worst scenario corresponds to an unstable volume in the order of up to 48 ± 12*106 m3. The opposite, eastern slope of the same mountain ridge is also affected by wide deformation involving an area of 0.37 km2. Here, field data indicate 2-5 cm/y of short-term and long-term slip rates. Ground Penetrating Radar surveys of the head scarps confirm that these slip planes are steep and extend downward. All these evidences are interpreted as resulting from two similar landslides, whose possible causes are discussed, comprising seismic triggering, mountain rapid uplift, river erosion and lake variations.

Publisher's Statement

© Author(s) 2018.CC BY 4.0 License. Publisher’s version of record: https://doi.org/10.5194/nhess-2018-186

Publication Title

Natural Hazards and Earth System Sciences

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Version

Publisher's PDF

Download

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.