Adnan Özdemir

Selcuk University, Conia, Konya, Turkey

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Publications (2)2.77 Total impact

  • Adnan Özdemir, Mehmet Delikanli
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    ABSTRACT: In this study the factors affecting the retrogressive Yaka Landslide, its mechanism and the hazard of debris flow on the town of Yaka are investigated. In the landslide area, the first landslide was small and occurred in March 2006 on the lower part of the Alaardıç Slope near the Gelendost District town of Yaka (Isparta, SW Turkey). The second, the Yaka Landslide, was large and occurred on 19 February 2007 in the soil-like marl on the central part of Alaardıç Slope. The geometry of the failure surface was circular and the depth of the failure surface was about 3m. Following the landslide, a 85,800m3 of displaced material transformed to a debris flow. Then, the debris flow moved down the Eglence Valley, traveling a total distance of about 750m. The town of Yaka is located 1,600m downstream of Eglence Creek and hence poses a considerable risk of debris flow, should the creek be temporarily dammed as a result of further mass movement. Material from the debris accumulation has been deposited on the base of Eglence Valley and has formed a debris-dam lake behind a debris dam. Trees, agricultural areas, and weirs in the Eglence Creek have seen serious damage resulting from the debris flow. The slope angle, slope aspect and elevation of the area in this study were generated using a GIS-based digital elevation model (DEM). The stability of the Alaardıç Slope was assessed using limit equilibrium analysis with undrained peak and residual shear strength parameters. In the stability analyses, laboratory test results performed on the soil-like marls were used. It was determined that the Alaardıç Slope is found to be stable under dry conditions and unstable under completely saturated conditions. The Alaardıç Slope and its vicinity is a paleolandslide area, and there the factor of safety for sliding was found to be about 1.0 under saturated conditions. The Alaardıç Slope and the deposited earthen materials in Eglence Creek could easily be triggered into movement by any factors or combination of factors, such as prolonged or heavy rainfall, snowmelt or an earthquake. It was established that the depth of the debris flow initiated on the Yaka Landslide reached up to 8m in Eglence Creek at the point it is 20m wide. If this deposited material in Eglence Creek is set into motion, the canal that passes through Yaka, with its respective width and depth of 7 and 1.45m, could not possibly discharge the flow. The destruction or spillover of this canal in Yaka could bring catastrophic loss to residents which are located within 3–5m of the bank of the canal. Furthermore, if material present in the landslide source area slides and this displaced material puts pressure on the unstable deposited material in Eglence Creek, even more catastrophic loss would occur to the town of Yaka. In this study, it was determined that debris flows are still a major hazard to Yaka and its population of 3,000. The results provided in this study could help citizens, planners, and engineers to reduce losses caused by existing and future landslides and debris flow in rainfall and snowmelt conditions by means of prevention and mitigation.
    Natural Hazards 01/2009; 49(1):113-136. · 1.64 Impact Factor
  • Adnan Özdemir
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    ABSTRACT: This study examines the local geological conditions and soil structure as possible causes of the collapse of the Zümrüt Building 2 February 2004. This catastrophe resulted in 92 fatalities and 35 injuries. This study also examines other views which claim weak soil structure, elastic and consolidation settlement of soil and excessive groundwater extraction as well as subsidence resulting from the underground silt erosion as possible factors. Zümrüt Building was constructed on normally consolidated, low plasticity clay. The underground water table was 30m in depth. The internal friction angle of soil was 8°–30°, its cohesion was between 34 and 127kN/m2 and standard penetration test numbers varied between 11 and 50. The underground water level beneath Zümrüt Building had risen 4.5m since its construction. Therefore the claim that subsidence resulting from the decrease of underground water level contributed to the collapse is incorrect. Secondly the settlement, resulting from the filling up of the pores created by the silt receding with the underground water, was 4.4mm in total, and attributing this as the primary cause of the collapse is also incorrect. Soil properties, in situ and laboratory test results showed that the existing and/or expected settlement and the differential ground settlement in the Zümrüt building vicinity had the potential to cause structural damage. The tensile stresses caused by differential settlements recorded here are thought to be an indicator, but not the main cause contributing to the collapse of the building. The Zümrüt Building collapse was due to several compounding mistakes during the construction phase. These were geotechnical and other project faults and the use of low quality construction materials. The resulting catastrophe caused 92 fatalities, 35 injuries and a material loss of approximately US$7million.
    Environmental Geology 01/2008; 53(8):1695-1710. · 1.13 Impact Factor

Publication Stats

6 Citations
2.77 Total Impact Points

Top Journals

Institutions

  • 2008–2009
    • Selcuk University
      • Department of Geological Engineering
      Conia, Konya, Turkey