Research on Similar Materials for Rheological Test of Hard Rock Mass

Abstract

The analog material, used in the Geo-mechanical model test that is designed to study the unloading rheological behavior and failure characteristics of rock mass, must reflect the physico-mechanical behaviors of the actual rock mass. The surrounding rock of Meng-di-gou hydropower station is in complex geological conditions. With the excavation of the rock mass, the surrounding rock gradually unloading, and the property of the near rock mass. It is necessary to carry out Geo-mechanical model test to study the rheological properties of deep rock mass under complicated geological conditions. So the similar material, comprised of iron powder, barite powder, and quartz sands bound with a solution of alcohol and colophonium, is suggested to be improvable. Firstly, through more than 300 groups of mix proportion tests, the influence of different mix proportions of the ingredients are analyzed to obtain the optimal analog materials; Secondly, more than 1200 specimens are made into size Φ50mm×100mm; Lastly, physico-mechanical tests were conducted by using the specimens to test the mechanical property of the similar material, and the basic physico-mechanical parameters are obtained from the analog material. The results indicates that the property of the similar material matches well with that of the rock mass in site, so the similar material is suitable for the Geo-mechanical model test, and it can be used to test the unloading rheological behavior of rock mass of Meng-di-gou hydropower station.