Macro-micro Quantitative Relations of Rock Mechanical Properties Considering Chemical Weathering

Abstract:

In order to analyze the effect mechanics of chemical weathering on the mechanical properties of rock， in this paper， the densely packed particle assembly is used to simulate rock materials， and the mass loss rate related to chemical weathering time is introduced into the particle stiffness and contact model. Through the homogenization method and lattice model， the stress-strain relation in elastic stage， strength criterion and macro and micro quantitative relations of elastic and strength parameters with microscopic parameters （e.g.， inter-particle contact properties， weathering damage parameters） of rock are obtained， and the effects of chemical weathering and aging are investigated. The results show that with the increase of mass loss rate and erosion time， the stiffness and strength negative exponentially decrease. For the lower environmental pH value， both of the peak cohesion and peak internal friction angle decrease significantly with reaction time； while for the higher environmental pH value， the peak cohesion reduces significantly and the peak internal friction angle almost keeps constant in a short time， and more environmental time is needed for the decrease of peak internal friction angle.