Abstract:  In this paper, in order to improve the accuracy of similar simulation experiment, we tested the stress-strain behaviors of similar material specimens with different compositions (sand-plaster, sand- cement-plaster) and proportions by uniaxial compression testing, analyzed the mechanical properties and post-peak failure characteristics, and investigated the error sources during the production of similar material models and testing of specimens. The results show that: 1) The two similar materials both show good elastic-plastic properties in the loading process, thus, they can be used to simulate different rock mass; 2) The post-peak strain-softening processes of the two materials are smooth, and the residual strengths are stable; 3) Due to the insufficient cementation and primary damage of the similar materials, abnormal pressure-relief and stress fluctuations are prone to appear in the loading process, and the main failure modes are the tensile failures and conjugate shear fracturings; 4) Human factors affect a lot during the production procedures of similar material models, thus, in order to increase the accuracy of similar material experiment, we put forward the error sources in the preparation and test processes and try to avoid them.

Key words: similar material, uniaxial compression, mechanical property, error source