Browsing by Author "Akin, Muge"

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Landslide Investigation of a Residential Area in Goynuklu Village, Bursa (Turkey)
(Springer International Publishing AG, 2017) Topal, Tamer; Akin, Muge; Doyuran, Vedat
Landslide is a natural process of the earth's surface, inevitably resulting from gravity with many triggering factors such as rainfalls, earthquakes, slope steepening, removal of vegetation, etc. The most frequent landslide-triggering mechanism is water from intense rainfall or human-based sources. The wide ranges of landslides and the complexity and variability of their interactions with the environment are the key points of a landslide investigation. The rate of the movement is the main factor of high property damages. On 16th of March in 2006, a rapid landslide occurred in Goynuklu village in Bursa, Turkey. The properties were inevitably damaged after the failure. The triggering factors of the failure mechanism and the properties of the landslide were investigated to specify proper remedial measures at the site. The geotechnical investigations including surface and subsurface studies were performed to determine the extent of the landslide and its sliding surface accurately. Within the framework of the geotechnical investigations, the inclinometer measurements were also recorded after drilling boreholes. Besides, a number of trial pits were excavated for evaluating the shallow sliding surfaces. Samples taken from the boreholes and trial pits were tested in the laboratory to obtain the soil class and the distribution of the grain size of the soil layers as well. The field tests including the hydraulic effect on the soil layers were also resolved by means of in situ permeability tests. Based on the data obtained, the characteristics and mechanism of the landslide were analyzed. The landslide occurred on a translational sliding surface in Neogene sediments including non-stratified sandstone-siltstone-claystone layers and a landfill site in a residential area. The shear strength characteristics of the sliding surface were calculated by back-analyses.
Citation - WoS: 3
Citation - Scopus: 3
Experimental Investigation of Soil Disturbance Effect on Bearing Capacity of Organic Soil
(Springer int Publ Ag, 2024) Cadir, Cenk Cuma; Kaya, Zulkuf; Yalcin, Hakan; Erol, Aykut; Uncuoglu, Erdal; Akin, Muge
The model test investigations on the soft soils are usually carried out on samples prepared in the laboratory and assuming site conditions. However, such soils that are prepared in the laboratory only partially reflect the site conditions. Considering this gap in the literature, this study mainly focuses on the bearing capacity and settlement behavior of the undisturbed organic soil obtained by a novel block sampling technique. The disturbed organic soil prepared in the laboratory was investigated with large-scale model experiments for two different footing types (square and rectangular). Vane Shear testing (VST), Dynamic Cone Penetration (DCP) tests, and finite-element analysis (FEA) were performed. The average bearing capacity values of disturbed and undisturbed soil were 60.98 kPa-68.71 kPa and 108.18 kPa-110.89 kPa for square and strip footings, respectively. Bearing capacity reductions of up to 40% were determined on laboratory-prepared soils. The cone reached the required depth (450 mm) with three blows for disturbed soil, while it was reached with four blows for undisturbed soil. Likewise, the undrained shear strength obtained by the VST was determined as 22.16 kPa and 16.60 kPa for undisturbed and disturbed soils, respectively. Shear strength losses of up to 25% for disturbed soils were observed. The bearing capacity values obtained from FEA were comparable to those obtained with the model tests. It was concluded that the degree of degradation of organic soils in the laboratory significantly affects the bearing capacity of the soil.
Citation - WoS: 6
Citation - Scopus: 7
Improvement of an Undisturbed Peat Soil With Jet Grout Columns: Physical and Numerical Modeling
(Springer Heidelberg, 2023) Yalcin, Hakan; Kaya, Zulkuf; Cadir, Cenk Cuma; Uncuoglu, Erdal; Erol, Aykut; Akin, Muge
The bearing capacity of the composite-formed soil, such as grouted peat soil, is a crucial design parameter that can be improved by employing jet grout columns (JGCs). The coupling effect of the requirement of new industrial sites and reduction in the suitable regions for construction requires research on improving the bearing capacity of abundantly available peat soils. Despite routinely reported studies on peat soil, improvement studies basically took upon the disturbed soil samples. Research on the sample collecting techniques or experiments on undisturbed peat soil has not been conducted intensively. This study uses a domestic jet grout device to compare features of the undisturbed peat soils at the laboratory using axial loading tests. While samples were collected undisturbedly using specially designed steel boxes, the peat soil within the steel boxes was improved by jet grout columns. Additionally, PLAXIS 3D simulations were used to estimate the behavior of the improved soil. Results showed that the bearing capacity of the soil increased 4 times for square foundations (2 x 2 JGC) and 4.5 times for strip foundations (3 x 1 JGC) compared to the unimproved organic soil.