ABSTRACT: As a result of the characteristics of Ankara Clay, such as its overconsolidated, active, highly plastic, and stiff consistency, obtaining undisturbed samples is challenging and adversely affects the reliability of laboratory test results. Due to this problem, studies in the literature have been mainly limited to shallow depths and no depth-related evaluation has been performed. Within the scope of this research, soil characterization studies related to depth have been carried out using approximately 5500 samples obtained from in-situ field and laboratory tests from clay units located in the west of Ankara at different depths. The frequency distributions of geotechnical parameters have been statistically examined, empirical equations have been developed between parameters, and the effect of sample disturbance has been evaluated. To quantify the effect of disturbance and to verify the accuracy of the identified relationships between soil parameters, laboratory test results have been compared with the existing literature, and sensitivity changes between undisturbed-disturbed and remolded samples, in terms of undrained shear strength (Cu) and liquidity index (LI) values, have been identified. Considering these studies, an approach for identifying disturbed samples has been proposed. The method was tested with validation studies using laboratory results from clayey soils with similar soil properties. As a result of excluding the samples detected as disturbed within the proposed method from the dataset, high percentages of increases have been observed in the success of predicting undrained shear strength in the empirical equations developed both in the literature and within the scope of the study. In conclusion, the present study has not only provided a detailed depth-dependent characterization of the Ankara Clay, but also a new perspective for evaluating the effects of disturbance on sensitive clay samples. These findings have practical implications, especially in civil and geotechnical engineering where soil behavior at different depths is essential for the stability and design safety of underground structures.