Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
2 results
Search Results
Master Thesis Effect of Fines and Ground Acceleration on Liquefaction Resistance of Silty Sand: Numerical Study(Izmir Institute of Technology, 2022) Tozburun, Batuhan; Ecemiş Zeren, NurhanLiquefaction is a phenomenon that damages structures that have not been adequately studied during the design process. While improving the performance of the buildings under dynamic loading conditions, it is essential to evaluate the liquefaction behavior of soils under the dynamic load. In this thesis, the constitutive soil model (UBCSand Model), which can simulate liquefaction, is used within the finite difference methods (FDM). First, results are compared with the laboratory test results to verify numerical liquefaction simulations. The physical and mechanical tests performed at Izmir Institute of Technology (IZTECH) are used as an input for the soil model. Then, a series of constant volume cyclic direct simple shear results (CDSS) tests performed for the same silty sands were used to verify the numerical study (Tutuncu, 2021 and Monkul, 2021). CDSS tests were performed on mixtures of clean sands and three non-plastic silts at different contents of 0%, 5%, 15%, and 35% allowing for observing the liquefaction response of silty sands of different grades (Monkul, 2021). The laboratory tests performed at Yeditepe University and Izmir Institute of Technology were combined to study the effect of fines content and relative density on cyclic liquefaction resistance of silty sands. The aim of this thesis is to perform a numerical model to evaluate the effect of fines content (FC), ground acceleration (amax) and relative density (Dr) on liquefaction resistance. The FDM model gives similar results to laboratory test results. Hence, the model can be used to assess the liquefaction with different soil models and conditions.Master Thesis Effect of Fines Content on Cpt Resistance in Silty Sands(01. Izmir Institute of Technology, 2021) Arık, Mustafa Sezer; Ecemiş Zeren, NurhanThe effect of fines content on cone penetration resistance and excess pore water pressure is not entirely known yet. In this study, CPTu, SCPT, and DPPT tests in a fixed wall laminar box were carried out to understand the effect of fines content with different relative densities on cone penetration resistance and excess pore water pressure in clean sand and sand with 5, 15, and 35 percent silty. This study was investigated by using the normalized penetration rate. The effect of normalized penetration rate accounted with penetration rate and coefficient of consolidation on drainage conditions and the value of transition from partially drained to drained conditions were investigated. According to the experimental data results, the effect of fines content on the coefficient of volume compressibility is minimal. However, as the fines content increase, the permeability and the coefficient of consolidation decrease considerably. The normalized cone penetration resistance decreases when the fines content increases in clean sand and silty sands at the same relative densities. When the relationship between normalized penetration rate and normalized cone penetration resistance is examined instead of only the fines at the same relative densities, the normalized cone penetration resistance decreased with the increasing normalized penetration rate. Due to a decrease in the coefficient of consolidation or an increase in the penetration rate, silty sands have a longer dissipation time of excess pore water pressure than clean sand. Hence, the clean sand remains drained, and the silty sands remain partially drained.