Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2018Bearing capacity and slope stability assessment of rock masses at the Subasi viaduct site, NE, Turkey
Kaya, Ayberk; Bulut, Fikri; Dağ, Serhat
This study investigates the bearing capacity of rock masses and stability of slopes at the Subasi viaduct site which is a part of the improvement project of the Artvin–Hopa government highway between KM 6 + 500 and 13 + 787 in NE Turkey. The geotechnical studies were performed in three stages. Firstly, the bearing capacity of moderately weathered andesitic tuff was evaluated using the empirical equations. Secondly, the major principal stress and vertical displacement due to the viaduct and traffic loadings at the level of foundations were determined by the finite element method (FEM). The vertical displacement value and comparison of bearing capacity and major principal stress show that any problem is not expected at the viaduct site in terms of the bearing capacity. Finally, the stability of slopes at the viaduct site was investigated using kinematic, limit equilibrium, and finite element method-based shear strength reduction analyses methods. It was concluded that no discontinuity controlled failures at the slopes are expected. However, a circular failure is possible to occur at the face slope excavated in highly weathered andesitic tuff. After support application, the long-term stabilization of face slope has been achieved. Consequently, it is suggested that the empirical, analytical, and numerical methods should be combined for a more reliable construction design.
AtıfScopus6WoS5OpenAlex10İncele - MakaleAçık Erişim2015Scopus SJRQ2Utilization of the limit equilibrium and finite element methods for the stability analysis of the slope debris: An example of the Kalebasi District (NE Turkey)
Alemdag, Selcuk; Kaya, Ayberk; Karadag, Mustafa; Gurocak, Zulfu; Bulut, Fikri
The stability of the slope debris in residential area of the Kalebasi District (Ozkurtun-Gumushane) was investigated using the Limit Equilibrium (LE) and Finite Element Shear-Strength Reduction (FE-SSR) methods. Along the survey lines, four trial pits were dug and fourteen boreholes having a total length of 345m were drilled. Also, seismic refraction studies were conducted along the five lines. According to the field studies, thickness of the slope debris covering the 98ha of the study area varies between 1 and 36m. To determine the physical and shear strength properties of the slope debris, undisturbed samples were taken from the trial pits. As a result of the laboratory tests, soil categories of the debris were found to be as Clayey Sand (SC), Silty Sand (SM) and Low Plasticity Clay (CL). The deformation-controlled shear box tests were carried out to determine the shear strength parameters of the slope debris. According to these tests it was found that the peak cohesion and peak friction angle varies between 2.63-16.35kN/m2 and 20-27°, respectively. Stability analyses were performed using the obtained data from field and laboratory investigations in the Slide v5.0 and Phase2 v6.0 software programs and results were compared. In LE stability analyses, the factor of safety (FOS) of survey lines were found to be as 1.44, 1.80, 1.96, and 1.72; however for the FE-SSR method they were determined as 1.39, 1.72, 1.59, and 1.58, respectively.
AtıfScopus42WoS36İncele - MakaleYalnız künye2012Scopus SJRQ4Coğrafi bilgi sistemleri tabanlı heyelan duyarlılık haritalarının hazırlanmasına bir örnek: Çayeli (Rize, KD Türkiye)
Dağ, Serhat; Bulut, Fikri
Ülkemizin en fazla yağış alan ve engebeli bölgelerinden biri olan Karadeniz Bölgesi’nde ve özellikle de Doğu Karadeniz Bölümü’nde meydana gelen doğal afetlerin başında heyelanlar gelmektedir. Bölge açısından heyelanların oluşturduğu hasar, uzun vadede dikkate alındığında, depremden daha fazladır. Bu çalışmada, Çayeli yöresinde 2002 yılı temmuz ayındaki sağanak yağış sonucunda meydana gelen heyelanlar araştırılmış ve inceleme alanının heyelan duyarlılık haritası hazırlanmıştır. İlk olarak heyelan envanter haritası oluşturulmuş ve toplam 149 adet heyelan haritalanmıştır. Arazi incelemeleri sonucunda litoloji-ayrışma, yamaç eğimi, yamaç eğim yönü, arazi örtüsü, yükseklik, akarsuya yakınlık faktörleri, heyelana neden olan parametreler olarak değerlendirilmiştir. İnceleme alanına ait topoğrafik ve tematik haritalar kullanılarak Coğrafi Bilgi Sistemleri (CBS) tabanında parametre haritaları üretilmiştir. Haritalar mevcut heyelanlarla ilişkilendirilerek frekans oranı değerleri belirlenmiştir. Bu değerlendirmelere göre, tamamen ayrışmış dasit ve piroklastitleri ile tamamen ayrışmış andezit-bazalt ve piroklastitlerinin heyelan oluşumunda etkili olduğu düşünülmektedir. Yine eğim sınıflarından 0º - 20º arası, yamaç eğim yönü sınıflarından kuzey-kuzeydoğuya bakan yamaçlar, topoğrafik yükseklik sınıflarından 0 - 200 m arasındaki yükseklik sınıfları elde edilen değerlere göre önemli görülmüştür. Benzer şekilde tarımsal alan ve yerleşim alanlarından oluşan arazi sınıfları ile 0 - 100 m arasındaki akarsuya yakınlık sınıfları da ikili karşılaştırmalarda önemli olarak değerlendirilen parametre sınıflarıdır. Daha sonra ağırlık değerleri hesaplanmış ve bu değerler dikkate alınarak heyelan duyarlılık haritası üretilmiştir. Son olarak üretilen haritanın performansını analiz etmek için mevcut heyelanlarla duyarlılık haritası karşılaştırılmış ve mevcut heyelanların % 81’inin duyarlı, yüksek ve çok yüksek duyarlı alanlarda bulunduğu belirlenmiştir.
AtıfTR Dizin20İncele - MakaleYalnız künye2011Applicability of excavatability classification systems in underground excavations: A case study
Kaya, Ayberk; Bulut, Fikri; Alemdaǧ, Selçuk
In this study, applicability of the excavatability classification systems in underground excavations is investigated. For this purpose, the entrance portal of the Konakönü (Arakli{dotless}-Trabzon) tunnel, excavated in volcanic rocks within the scope of Black Sea coastal highway project, is chosen as pilot study area. The entrance portal of tunnel is excavated through the rocks of Eocene-aged Kabaköy formation of basaltic-andesitic tuffs, aglomerate and basalt. In excavation, basaltic and andesitic tuffs were ripped by using hydraulic breaker; aglomerate and basalt were excavated by using explosives. Based on the results obtained from field and laboratory studies, rock masses are classified in terms of excavatability. According to Pettifer and Fookes (1994), basaltic and andesitic tuffs are included in "hard ripping", aglomerate and basalt in "blasting required" categories. With reference to Tsiambaos and Saroglou (2009), basaltic and andesitic tuffs fall in "ripping", agglomerate and basalt in "hammer and blasting" categories. It was found out that the classifications made according to these two methods are completely compatible with in-situ excavation works. Also, it is determined that the parameters give the best results for determining excavation class in underground excavations are GSI (Geological Strength Index), I s (50) (Point load strength index) and I f (Discontinuity spacing index).
AtıfScopus14İncele - MakaleYayıncıda açık erişim2011Analysis of support requirements for a tunnel portal in weak rock: A case study from Turkey
Kaya, Ayberk; Bulut, Fikri; Alemdaǧ, Selçuk; Sayin, Aytuna
In this paper, engineering geological properties of the entrance portal section of Konakönü Tunnel, located on Black Sea Coastal Highway, Turkey, is studied. Moderately weathered basaltic and andesitic tuffs orderly to be driven by the entrance portal section. Tunnel portal design in weak rock presents some special challenges to the designers, since misjudgements in the design of tunnel can lead to very costly failures. The entrance portal was analyzed by empirical and numerical methods. Both field and laboratory studies were carried out during this study. Field studies involved geological mapping, detailed discontinuity surveying and sampling. Laboratory tests were carried out to determine the physico-mechanical and elastical properties of rock units. For this purpose, tunnel stability analyses were performed at the entrance portal section. The RMR (rock mass rating), Q (rock mass quality), RMi (rock mass index), NATM (new Austrian tunnelling method) and GSI (geological strength index) systems were employed for empirical rock mass quality determination and preliminary tunnel portal support design. The parameters calculated by the empirical methods were used as input parameters for the FEM (finite element method) analysis. The results from the two methods were compared and preliminary support designs were carried out. This comparison suggests that for more reliable support design, empirical and finite element methods should be combined.
AtıfScopus32OpenAlex33İncele - MakaleYalnız künye2008Landslide susceptibility mapping for a landslide-prone area (Findikli, NE of Turkey) by likelihood-frequency ratio and weighted linear combination models
Akgun, Aykut; Dag, Serhat; Bulut, Fikri
Landslides are very common natural problems in the Black Sea Region of Turkey due to the steep topography, improper use of land cover and adverse climatic conditions for landslides. In the western part of region, many studies have been carried out especially in the last decade for landslide susceptibility mapping using different evaluation methods such as deterministic approach, landslide distribution, qualitative, statistical and distribution-free analyses. The purpose of this study is to produce landslide susceptibility maps of a landslide-prone area (Findikli district, Rize) located at the eastern part of the Black Sea Region of Turkey by likelihood frequency ratio (LRM) model and weighted linear combination (WLC) model and to compare the results obtained. For this purpose, landslide inventory map of the area were prepared for the years of 1983 and 1995 by detailed field surveys and aerial-photography studies. Slope angle, slope aspect, lithology, distance from drainage lines, distance from roads and the land-cover of the study area are considered as the landslide-conditioning parameters. The differences between the susceptibility maps derived by the LRM and the WLC models are relatively minor when broad-based classifications are taken into account. However, the WLC map showed more details but the other map produced by LRM model produced weak results. The reason for this result is considered to be the fact that the majority of pixels in the LRM map have high values than the WLC-derived susceptibility map. In order to validate the two susceptibility maps, both of them were compared with the landslide inventory map. Although the landslides do not exist in the very high susceptibility class of the both maps, 79% of the landslides fall into the high and very high susceptibility zones of the WLC map while this is 49% for the LRM map. This shows that the WLC model exhibited higher performance than the LRM model.
AtıfScopus361WoS312OpenAlex382İncele