###### Abstract  
The Marchetti Dilatometer test is a non-destructive in situ test that can be used to determine the geotechnical properties of soils. This paper presents the results of a study that investigated the correlations between the parameters obtained from the Marchetti Dilatometer test and geomechanical parameters for soft soils, mainly organic soils, obtained in the laboratory. The study was conducted in the El Garrochal sector in Southern Quito, Ecuador. The results of the study showed that there are significant correlations between the Marchetti Dilatometer test and the undrained shear strength, modulus of elasticity, and density of soil. The equations that were developed in this study can be used to estimate these geomechanical parameters from the results of the Marchetti Dilatometer test for the South Quito sector, which are valuable for geotechnical engineers to design structures in these types of soils. The equations that were developed in this study can be used to improve the accuracy of the design of these structures. Marchetti Dilatometer test; soft soils; organic soils; geomechanical parameters; undrained shear strength; modulus of elasticity; density of soil; correlations 2023 138570 2  
It should be noted that the final product of this work seeks to complement and accompany the correlations that are already in use today and were derived by [PERSON]. Since organic soils require an independent study, the results obtained may vary from those obtained by [PERSON]'s equations. [PERSON] published a series of correlations, which refer to the derivation of soil parameters, based on tests carried out in Italian locations [2]. Although these equations allow us to find reliable geomechanical parameters using the Dilatometer results, and these have been validated in the country, it would be convenient to obtain our equations to increase the level of precision of the parameters to be obtained, especially in organic soils which, due to their composition, require special care at the time of design [4; 5]. Relying solely on existing correlations derived from limited geographical locations may not capture the full range of soil behavior and properties. Developing new research on DMT and its correlations enables us to tailor and refine these relationships specifically for different soil types found. This ensures that geotechnical engineers have access to reliable and region-specific correlations, leading to more accurate assessments, optimized designs, and cost-effective solutions for various geotechnical challenges. The field of site investigation has witnessed a growing trend in the use of in situ tests, driven by recent research papers (e.g., [PERSON] 2015 [6], [PERSON] et al., 2016 [7]). These tests, including the electrical cone penetration test (CPT), piezocone penetration test (CPTu), and the standardized Marchetti flat dilatometer test (DMT), offer rapid, cost-effective, reproducible, and information-rich data [8]. The Marchetti flat dilatometer is particularly valuable as a standardized test that approximates foundation settlement and determines the coefficient \(K_{O}\) of the soil. Ongoing developments have expanded its applications, encompassing controlling compaction systems, identifying sliding surfaces on slopes, evaluating soil liquefaction, assessing deformations in laterally loaded piles, and addressing various geotechnical challenges through correlation-based approaches [9]. Aligned with the concept of spade-shaped in situ testing probes, instrumented DMTs have been developed and examined for diverse objectives [10]. These advancements further enhance the versatility and utility of the flat dilatometer test. The influence of partial drainage is notable, with parameters derived from lift-off pressure significantly affected, while parameters relying on both pressure difference and lift-off pressure show less influence [11].