In the microscopic view

rock is composed of crystal grains and the contacts between them. During the chemical weathering process

the bonding materials are corroded and the connections between the particles are weakened which would lead to evident aging effect on the mechanical properties of rock. Based on the existing contact model

the chemical weathering process of rock was idealized as the solution of the bonding materials which resulted in the decay of the strength and stiffness of the bonds between the particles. In this way

the factor of chemical weathering is induced into the existing contact model. According to establishing contact model considering chemical weathering

DEM is used to simulate and analyze the corroded experiments and the discrete element simulation results. The results show that: the new model can reflect the aging effect on the strength of rock; the strength will decrease with the erosion; the new model can reflect the aging effect after the fracture pressure stage in the compression test. The elastic modulus and failure strain will decrease with the erosion; the failure of bonds between the particle

namely the growth of the microfracture

is the reason that leads to the aging effect. At the same time

the simulation results of the tests combined chemical weathering and loading show that a suitable construction speed should be chosen to ensure a safe and efficiency construction.