Discrete element analysis of chemical weathering on rock

Abstract

A time-dependent problem, the chemical weathering on rock material, is studied in this work. The process of this issue is regarded as weight loss with the increase of weathering time for simplicity. This weight loss is represented by the ratio of weight loss α and then is introduced as a factor of chemical weathering into the micro-contact model considering size change of bond (e.g. width and thickness change) in discrete element method (DEM). Then, DEM results are validated by experimental data and show that the strength and elastic modulus of the rock sample decrease with the increasing weathering time. There are two major failure mechanisms of bond breaking, e.g. tensile with shear and rolling break and compressive with shear and rolling break. The number of compressive with shear and rolling bond breaking is firstly smaller while is getting greater than that of tensile with shear and rolling bond breaking. What’s more, the final breakage form for rock samples changes from overall failure to local failure with the extending time.

Keywords:

• DEM
• chemical weathering
• time-dependency
• contact model

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is funded by the Major Project of Chinese National Programs for Fundamental Research and Development (973 Program) [grant number 2011CB013504], [grant number 2014CB046901]; China National Funds for Distinguished Young Scientists [grant number 51025932]; State Key Lab. of Disaster Reduction in Civil Engineering [grant number SLDRCE14-A-04]. These supports are greatly appreciated.