## 1 Introduction
The alluvial and water-saturated nature of the region played a significant role in this amplification. [PERSON] [8] investigated the geology of Sakarya province, identifying the geomorphological characteristics of its alluvial soils and analyzing their geotechnical index properties. The study also examined the formation of Adapazan soils and predicted the distribution of potential earthquake damage. [PERSON] [9] conducted field experiments in 12 locations in the Adapazan district, focusing on soil profiles and evaluating the liquefaction potential based on the region's seismicity. Various laboratory tests are employed to determine the dynamic parameters of undisturbed soils. These include dynamic triaxial (TRX) tests, resonant column (RC) tests, and bender element tests [8; 10; 11]. To estimate the stress-strain behavior of in situ soils under cyclic loads, dynamic properties must first be assessed before conducting site-specific analyses to predict the behavior of both the ground and superstructures. Parameters such as the initial dynamic shear modulus (G\({}_{\text{max}}\)), normalized dynamic shear modulus (G/G\({}_{\text{max}}\)), and damping ratio (D) are essential for defining dynamic soil properties [10; 11]. TRX and RC tests are widely used, as recommended by ASTM D4015-15 and D4767-11 [12; 13]. The choice of test depends on the shear strain level: RC tests are suitable for shear strains below 0.01%, while TRX tests are used for higher strain levels. [PERSON] and [PERSON] [14] used Monterey sand in RC tests to derive shear modulus and damping ratio curves, proposing formulations that link [PERSON]'s modulus, Poisson's ratio, shear modulus, and damping values. [PERSON] et al. [15] explored the dynamic propertiesof clay samples using RC tests, examining the effects of saturation on shear modulus and Poisson's ratio. [PERSON] and [PERSON] [16] compared RC test results with a reference model and developed a new model incorporating additional parameters. [PERSON] et al. [17] performed RC tests on samples under varying conditions of density, saturation, and ambient confining pressure, obtaining shear modulus and damping ratio values. [PERSON] and [PERSON] [18] calculated the dynamic parameters of sands using the RC test system. [PERSON] [19] conducted TRX tests using Toyoura sand, investigating the effects of void ratios and comparing results with other studies. [PERSON] et al. [20] evaluated the dynamic properties of sand samples using TRX tests under different densities and confining pressures, comparing the results with reference models. In studies combining RC and TRX test systems, [PERSON] et al. [21] assessed the effects of bentonite additives on sand samples, while [PERSON] et al. [22] investigated similar conditions both with and without drainage. [PERSON] and [PERSON] [11] used a combination of RC, bender element, and TRX tests on samples with varying sand and gravel ratios, densities, and void ratios to analyze their effects on dynamic parameters. [PERSON] and [PERSON] [23] studied Chennai marine clay using RC and TRX tests, correlating strain rate with dynamic properties. [PERSON] and [PERSON] [24] determined the dynamic properties of sand and clay samples using RC and TRX tests, later analyzing the results using finite element methods. [PERSON] [25], in his doctoral research, conducted dynamic tests on undisturbed soil samples collected from 20 locations at various depths. These samples underwent RC and torsional shear tests, and the results were used to examine the effects of confining pressure, over-consolidation ratio, and frequency. Based on statistical analyses, a reference model was proposed for determining dynamic soil properties. [PERSON] [26] conducted centrifuge tests on clay samples over a wide stress range, scaling different earthquake records for one-dimensional analyses. The study concluded that nonlinear behavior dominated for periods shorter than T = 1.0 s, while linear behavior was more pronounced in longer periods.