Proposal of a chemical weathering model for mechanical analysis of cemented sandstone using DDA

A chemical weathering model based on Discontinuous Deformation Analysis(DDA) was proposed in this study to shed light on the microscopic origin of the mechanical behaviors of cemented sandstone with different chemical weathering degrees. The main deterioration of the microstructure induced by chemical weathering was represented by the loss of cement between polygonous grains skeleton. By conducting uniaxial compression tests, the result revealed that the proposed model that considered the geometric and contact heterogeneity was feasible to characterize the degradation of strength and deformation properties with the enhancement of the weathering degree. In addition, the discrepant failure patterns along the degree of chemical weathering were elaborated from the initiation of fracture at the grain scale, showing a correlation to the cement and porosity.