# Predictive Models for Correlation of Compaction Characteristics of Weakly Cohesive Soils
## 1 Introduction
The soil's ability to retain water at different mattic suction levels can be understood based on analysis of the influence of soil dry density on the soil-water characteristic curve (SWCC) [12]. Classical rheological models, such as Maxwell or Voigt-Kelvin, are often used to describe the viscoelastic behavior of soil compaction with vibratory rollers [13; 14; 15]. With the help of these models, it is possible to explore how soil's rheological properties affect the forces transmitted during compaction or how the mass and stiffness of the roller-soil model influence the process and provide guidelines for improving compaction efficiency. In the specialized literature, the influence of vibration frequency on the soil compaction process is a widely debated and extensively studied topic [16; 17; 18; 19]. This include aspects that explore how varying the frequency of vibratory rollers impacts the effectiveness of soil settlement. Research often investigates the correlation between frequency and the mechanical properties of the soil, including its stiffness, damping behavior, and viscoelastic response [20; 21; 22]. Thus, it becomes evident that frequency variation can optimize the compaction process, particularly when soil properties like moisture content, grain size, and composition are considered. Therefore, this research combines experimental data and numerical modeling to optimize the compaction process, emphasizing the importance of viscoelastic soil properties and their impact on achieving optimal compaction levels. Various studies [23; 24; 25] have shown that soil's longitudinal modulus increases as compaction progresses due to the reduction in void ratios and the corresponding increase in soil density. The modulus is often correlated with other mechanical properties like shear modulus and bulk modulus to assess soil deformation behavior under loads. In conclusion, the modeling of weakly cohesive soils raises a series of challenges due to their particular properties, which make their mechanical behavior difficult to analyze and predict. Some of the main difficulties include lack of cohesion (soils with a significant content of sands or silts with low cohesion have reduced mechanical strength under unconsolidated conditions), dependence on density and compaction (as a result of natural variability, as these soils are often heterogeneous, with variable particle distributions and porosity, making it difficult to achieve uniform results during modeling), sensitivity to water (these soils become unstable in the presence of water), nonlinear behavior under load (since there is no proportionality in the stress-strain relationship, complex constitutive models such as Mohr-Coulomb, Drucker-Prager, Cam Clay, etc., are required), and difficulties in sampling and testing (some laboratory tests may not reflect in situ behavior). Considering all these aspects, in this paper the authors develop a model for weakly cohesive soils, defined by inter-parametric laws that consider their initial state and predict the evolution of state parameters resulting from static and vibratory compaction processes, depending on the number of equipment passes.