Abstract:
Claystone degradation under the effect of freezing and thaw cycles represents a key aspect in the production of erodible material in mountain ranges. Erosion processes have numerous potential consequences such as dam filling, increment in slope instability, increase of badlands, among others. Due to the possible effects related to erosion, numerous research processes have been carried out following primarily experimental approaches based on both soil physical characteristics and mechanical properties. However, these have been based on a macroscopic scale.
This document presents the development of a research process based on the implementation of numerical models aimed at representing the processes involved in freezing and thawing phenomena on porous media and their effect on potential changes in soil microfabric. A calibration and validation process of the proposed numerical models was carried out based on experimental measurements of the thermal behavior of soil samples subjected to freezing and thawing cycles. Using the numerical relationships found, a methodology for determining the soil water retention curve (SWRC) was established (as a first approximation) based on a quick and relatively simple freezing and thawing test under undrained conditions.
Simultaneously, and following the main objective of the research, the microfabric state during cyclic freezing and thawing was established following the relationship between SWRC and pore size distribution (PSD), as well as the possible hysteresis between freezing and thawing processes. The significant effect of these thermodynamic processes on the state of the terrain, was identified particularly in regard to increased erodibility. One possible cause for particle detachment necessary for erosion processes to occur lies in the development of macroporosity along with the existence of gaps between pore families in the PSD. This behavior was observed through the developed numerical processes. The combined effect of freezing and thawing cycles leads to an increase in soil erodibility.
Finally, though a constitutive model-based approach, the cryogenic suction paths associated with freezing and thawing processes under the modification of the soil’s microstructure were established. A final perspective to soil's mechanical degradation is presented in terms of the hydraulic work associated with the cryogenic suction paths developed within the soil mass. Both the progressive evolution of the microstructure (through PSD) and the values of hydraulic work associated with each cycle show an attenuation in the incremental change as the cycles continue. Due to the numerical nature of the approximations and the trends found, further cyclical laboratory tests should be carried out. However, these represent a novel approach to the degradation phenomenon as well as the effects associated with the soil water retention curve.
Citación recomendada (normas APA)
Andrés Miguel Macías Gutiérrez, "Claystone degradation due to freezing and thawing cycles = Degradación de arcillita ante ciclos de congelamiento y deshielo", Colombia:-, 2023. Consultado en línea en la Biblioteca Digital de Bogotá (https://www.bibliotecadigitaldebogota.gov.co/resources/3711906/), el día 2025-07-03.
