Geotechnical characterization of soils prone to rainfall-induced landslides in Rize (Northern Turkey)

Download

index.pdf

Date

2019

Author

Üyetürk, Celal Emre

Metadata

Show full item record

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

Item Usage Stats

280
views

154
downloads

Landslides are common type of natural hazards around the world. Every year, hundreds of landslides are induced by rainfall in Rize. These landslides are shallow failures, generally having a maximum depth of 5 m. Although many of these landslides are observed every year, there is limited data on characteristics of these soils in the literature. Characterizing these soils is of paramount importance for numerical modeling of the landslide mechanisms, for landslide susceptibility mapping and for establishing rainfall intensity-duration thresholds. This study aims to investigate the characteristics of soils in rainfall-induced landslides in Rize. Disturbed and undisturbed samples are taken from a total of 12 landslide sites to evaluate the physical and mechanical properties and the mineralogy. Experiments including grain size distribution, Atterberg limits, organic content by mass and pH determination, mineralogy studies via X-Ray diffraction and Scanning Electron Microscopy, direct shear tests, unconfined compression tests, soil-water retention studies, hydraulic conductivity tests are conducted. Also, in-situ unit weights are determined on undisturbed samples, and portable hand vane tests are conducted to evaluate the in-situ undrained shear strength. Results indicate that these materials are relatively loose, medium-stiff, mostly fine-grained soils (low and high plasticity silts and high plasticity organic soils), and have relatively low pH. Direct shear tests on intact samples indicated that the average internal friction angle is in the range of 31.1-38.0 degrees in saturated condition; on reconstituted samples revealed the degree of saturation effects the shear strength and the volumetric response significantly.

Subject Keywords

Earthflows., Rainfall-induced Landslide, Residual Soil, Volcanic Soil, Direct Shear Test, Drying.

URI

http://etd.lib.metu.edu.tr/upload/12623335/index.pdf
https://hdl.handle.net/11511/43554

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Rainfall threshold to trigger landslides in unsaturated soils: A laboratory model study Ahmadi-adli, Mohammad; Huvaj Sarıhan, Nejan; Toker, Nabi Kartal (2017-09-22) Rainfall triggered landslides are common natural hazards with significant consequences all over the world. In this study, laboratory model tests are conducted which aims to obtain the rainfall intensity-duration threshold to trigger landslides in a slope composed of unsaturated soil in a flume setup. Sixteen laboratory model tests are conducted to obtain the rainfall intensityduration threshold. Some of the conclusions in this study are: (1) rainfall intensity-duration (I-D) thresholds that would trigger a ...
Risk assessment and pricing of natural hazards earthquake case Kestel, Sevtap Ayşe (null; 2015-10-16) The potential impacts of natural hazards are enormous. In such catastrophes the economies and human lives are exposed to unpredictable losses. Probabilistic modeling of such hazards require long term historical information which enables researchers to determine the potential risk for certain periods. However, even though its increasing trend in the frequency of such events, the factors influencing the magnitude of the losses are diverse and many. Earthquakes are the most severe one as its occurrence and sev...
Probabilistic Seismic Hazard Assessment of Seismically Induced Landslide for Bakacak-Duzce Region Balal, Onur; Gülerce, Zeynep (2014-09-19) Earthquake induced slope instability is considered as one of the major sources of the earthquake hazards, especially in the near fault regions. Simplified tools as Newmark's Sliding Block (NSB) analogy are commonly used to represent the slope stability during ground shaking since the outcome of this analogy is quantitative, larger NSB displacement values indicate higher seismic slope instability risk. Recently, empirical NSB displacement prediction models based on single or multiple ground motion intensity ...
Probabilistic seismic hazard assessment for sliding displacement of slopes: an application in Turkey Gülerce, Zeynep (2017-07-01) Earthquake-induced slope instability is one of the major sources of earthquake hazards in near fault regions. Simplified tools such as Newmark's sliding block (NSB) analysis are widely used to estimate the sliding displacement of slopes during earthquake shaking. Additionally, empirical models for predicting NSB displacement using single or multiple ground motion intensity measures based on global (e.g. NGA-W1 database, Chiou et al. 2008) or regional datasets are available. The objective of this study is to...
Effect of Unsaturated Soil Properties on the Intensity-Duration Threshold for Rainfall Triggered Landslides Kenanoğlu, Melih Birhan; Ahmadi-Adli, Mohammad; Toker, Nabi Kartal; Huvaj Sarıhan, Nejan (Teknik Dergi, 2019-03-01) Rainfall triggered landslides are one of the most common natural hazards in many countries throughout the world, as well as in Turkey. This study investigates the effect of unsaturated soil properties on landslide-triggering rainfall intensity-duration threshold. In addition to the time to failure, the suction (negative pore water pressure) distribution in the slope, the shape and depth of the failure surface are also evaluated. Properties of soil-water characteristic curve which affect the distribution of ...

Citation Formats

C. E. Üyetürk, “Geotechnical characterization of soils prone to rainfall-induced landslides in Rize (Northern Turkey),” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Civil Engineering., Middle East Technical University, 2019.