Seismic liquefaction behavior of different non-plastic silts

Soil liquefaction is a soil behavior observed in geotechnical engineering as a result of static or dynamic loads, with increased research on this subject in recent years. It was found that many parameters affect soil liquefaction such as fine-grain ratio (Fc), relative density (Dr), void ratio (e) can affect soil liquefaction. In this thesis, interesting findings were found by consolidating the liquefaction resistances of three different 100% non-plastic silts (TT-IZ-SI), which are rare compared to other studies in the literature, at constant volume and under 100 kPa vertical stress (σv). Another important point of this study is that the DSS tests are done with dry samples. In the experiments, dynamic load was applied at four different cyclic shear stress rates (CSR = 0.12, 0.14, 0.16, 0.18). In order to obtain void ratio values showed in all graphs mentioned in this thesis, the method of pulling with hand was applied. In this method, the effect of the velocity of the sample while it is being transferred to the container on the void ratio was investigated. The relationship between the liquefaction resistance, number of cycle and void ratio between the same silts and different silts were compared with the data obtained from the experimental results. All samples were compared in the number of cycle-constant selected void ratio graphs(e)( e= 0.97, 1.01, 1.05), and as a result, most plots consistently ranked from highest to lowest in liquefaction resistance; it is listed as TT-IZ-SI. Cyclic stress ratio-number of cycle graphs show that IZ and SI silts are very similarly parallel, but SI silt is more affected by void ratio change (Δe) than IZ silt. Cyclic resistance ratio (CRR) values at NL = 15 were found with the CSR values found. According to the CRR-e graph, it was found that the order of liquefaction resistance did not change as in the other graphs, but the effect between TT and IZ silts disappeared at 1.05 void ratio. In general, by examining all the graphs, data and results, it is argued that the liquefaction resistance cannot be evaluated according to a specific feature, and the most important factor affecting the liquefaction resistance of the samples is the shape effect.