Review of interaction mechanism between surrounding rock and support and analysis of conceptual model of rheological deformation mechanism

The essence of underground rock engineering supporting theory is interaction mechanism between surrounding rock and support. A detailed analysis of defects and errors in Kastner equation and current interaction mechanism is given as follows:(1) mechanical treatment of support reaction in the Kastner model may be flawed in its supporting time and loading path, which can not be used in engineering practice;(2) the ground characteristic curve deduced from Kastner equation doesn't exist practically and can not intersect with support reaction line;and (3) the equilibrium point solved by the intersection of ground reaction curve and supporting characteristic curve is wrong conceptionally and logically. Then, the conceptual model of rheological deformation mechanism is established. The calculations of project examples are offered, in which the course of the interaction between surrounding rocks and support is derived. It is proven that the concrete structure can be applied to the supporting structure of the tunnel in soft rock theoretically. The conceptional model of the rheological mechanism referred gives the qualitative explanation for the interaction between surrounding rock and support, and can be applied to the design and calculation in underground rock projects. The theoretical basis of the mechanism model is reliable, and has a bright future in engineering practice.