Abstract:

Similar materials used in geo-mechanical model test is commonly granular mixtures, and the influence on iron-barite-sand mixed similar material properties induced by molding pressure is remarkable, which was ignored by most researchers. The study of iron-barite-sand mixed similar materials properties was carried out. Under a certain pressure, the physical and mechanical parameters of the similar materials were measured quantitatively. The research results showed that the molding pressure could heavily affect the properties of similar materials. As the molding pressure increasing, the density, the compressive strength, the elastic modulus, the tensile strength and the cohesion force of similar material improved significantly, while the internal friction angle had no obvious change. The suitable similar materials was the key problem of geo-mechanical model test. Under high in-situ stress condition, the molding pressure of specimens should be equal to the compacting pressure of geo-mechanical model. Otherwise, the model test would be distorted or even be lost. Using the iron-barite-sand mixed similar materials, the zonal disintegration of deep tunnel reappeared repeatedly by strictly controlling the pressure.

Key words: geo-mechanical model test, similar materials, molding pressure, deep roadway, zonal disintegration