## 5 Conclusions  
This study provides a valuable dataset on typical silty soil from the Ecuadorian Inter-Andean Valley and demonstrates the applicability of empirical models for investigating unsaturated soils. It also emphasizes the importance of considering the hydroclimatic context, seasonal moisture cycles, and geological history when interpreting the mechanical tests, particularly when using natural samples. The mechanical behavior of unsaturated silty soil was analyzed through the experimental evaluation of both reconstituted and undisturbed samples under varying matric suction conditions. Based on the results obtained and a comparison with previous research, the following conclusions are drawn:  
1. Influence of Suction and Hysteresis Effects on Sample Type  
A unimodal model for the Soil Water Characteristic Curve (SWCC) satisfactorily represents the behavior of reconstituted samples. In contrast, the undisturbed samples did not conform well to either the Fredholm and Xing SWCC or unimodal models. This discrepancy indicates that suction values in undisturbed samples are strongly influenced by (i) soil type and the number of strata in the stratigraphic profile, because heterogeneous profiles exhibit distinct pore size distributions across layers, making a bimodal model more representative and resulting in varying suction values for similar degrees of saturation; and (ii) temporal precipitation variations, which induce cyclic wetting and drying processes that modify in situ suction depending on the sampling season. Samples collected after the peak precipitation month were in the drying phase, whereas reconstituted samples, which had been dried and rewetted to the target moisture content, were in the wetting phase. 2. Effect of Suction and Sample Type on Shear Strength and Elastic Modulus  
Two distinct behavioral regimes were observed in the reconstituted samples: within the low-suction range (\(\leq\)500 kPa), both shear strength and elastic modulus increased nonlinearly with suction; at high suction (>500 kPa), shear strength exhibited a decreasing trend after peaking, whereas the elastic modulus continued to increase but tended to stabilize. These trends align with previous studies, which reported significant nonlinear increases in shear strength and elastic modulus at low suction range for silty soils, followed by decreasing or plateauing behavior in the high-suction range within the capillary regime, for shear strength and elastic modulus, respectively. Reconstituted samples, consisting of homogeneous soil, displayed well-defined trends with good fits to the shear strength and elastic modulus models in the low-suction range, although the fitting quality declined in the high-suction range, likely owing to the reduced accuracy of the filter paper method. Undisturbed samples were analyzed only within the low-suction range and showed no clear trend for shear strength or elastic modulus as a function of suction. These samples possessed inherent macrostructures unique to each stratum, shaped by the geological history and stratigraphy of the site. Overall, the undisturbed samples exhibited higher strength at lower suction than the reconstituted samples, which was attributed to the in-situ conditions and the drying versus wetting phases at sampling, although the exact contributions of these factors were not quantified. For improved understanding, further studies are recommended employing active suction control and advanced characterization techniques, such as scanning electron microscopy (SEM) or computed tomography (CT), to elucidate the effects of macrostructure, adsorption regimes, and hysteresis. 3. Validity and Limitations of the Estimation Procedure and Practical Implications This work aligns with the estimation procedures and represents a feasible methodological approach for scenarios constrained by technical, logistical, or budgetary limitations that preclude advanced testing methods.