Analytical solution for rock mass bearing plate rheological tests based on a novel viscoelastic combination model

Abstract

The field bearing plate method test is the most commonly used method to determine rock mass deformation parameters. Currently, due to the effect of the applied test stress, the difference between the rheological model curve and test curve can be significant, namely the model cannot reflect the effect of the applied stress. In this study, a seven-component viscoelastic combination model that considers the effects of stress is proposed. Based on the proposed viscoelastic combination model and viscoelastic theory, the viscoelastic analytical solutions for the bearing plate tests are derived. Then, the viscoelastic characteristics of rock mass aging deformation as well as the effect of viscoelastic parameters on rock mass aging deformation are discussed. After that, a flexible bearing plate test and a rigid bearing plate test are carried out respectively, based on which the optimal rheological models and corresponding parameters of the rock mass aging deformation are identified according to the optimisation inversion method. Results indicate that the proposed combination rheological model with two Kelvin bodies is more preferable then that with only one Kelvin body. The bearing plate tests and the model parameters identification manifest that the proposed viscoelastic combination model is effective and reasonable.

Keywords:

• Field bearing plate rheological test
• viscoelastic combination model
• rock mass aging deformation
• analytical solution
• verification

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from the National Key Research and Development Program of China (No. 2017YFC1501305), the National Natural Science Foundation of China (Nos. 51779018, 51539002, 41807249), and the Basic Research Fund for Central Research Institutes of Public Causes (No. CKSF2019434/YT) are greatly acknowledged.