Development and application of high-geostress true 3D loading geomechanics model test system

Abstract: In order to simulate the non-linear deformation properties of deep In order to simulate the non-linear deformation failure properties of deep rockmass under high geostress, a true 3D loading geomechanics model test system is developed. This system is composed of a high-pressure loading system, an intelligent hydraulic controlling system and a counter-force apparatus system. The high-pressure loading system consisting of loading plates and the large-tonnage jacks is used to apply 3D high geostress for the test model. To solve the phenomenon that the adjoining loading plates disturb each other when the model is pressured, a hollow cube guiding frame is developed and set outside the test model. Through the guide installation fixed on the loading plate, the model opening can be excavated easily under axial loading, which solves the problem which the model opening cannot be excavated under axial loading. The intelligent hydraulic controlling system consisting of test control board and intelligent control sensors is used to exert load automatically and keep model pressure stable. The counter-force apparatus system which provides the counter force for the model is consists of model counter-force rack, flange plates and counter-force transferring plates. The non-linear deformation failure phenomenon of zonal disintegration in deep tunnels is effectively simulated through engineering application of the model system.