Grouting Mechanism In Fractured Rock Mass Based On Transfer Matrix Method

Grouting is an effective means to control the instability of fractured rock mass or the water inrush from the fracture,and it is widely used in surrounding rock engineering and underground mining conditions.However,due to the complex development of rock mass structural planes and the diversity of influencing factors of grouting reinforcement,grouting engineering practice was ahead of grouting theoretical research.The grouting parameters are mostly determined by experience.The current theory of grout spreading on rock mass structural planes The analysis model is generally limited to the assumption that there is no change in the opening degree of the fracture and the grout diffusion is only considered in a single fracture.It ignores the significant influence of the change in the width of the fracture caused by the grouting pressure and the displacement disturbance of the upper and lower fractures on the grouting diffusion process.Obviously this greatly affects the accuracy and rationality of the current grouting theory.Therefore,from the theoretical analysis of a single group of fractures to the study of the diffusion mechanism of the grout in the macroscopic overall grouting,the scientific design of the grouting scheme for the reinforcement of fractured rock masses and the smooth implementation of the project are guaranteed.Based on the Navier-Stokes theory based on the hypothesis of fluid clusters,this paper first derived the grout diffusion formula in a single fracture that considers the coupling effect of magmatic rock,and at the same time overcomes the previous assumption that the fracture has no opening change and only considers the grout diffusion in a single fracture.In this case,the transfer matrix algorithm is introduced,and the transfer matrix method is used to solve the fracture displacement at any position.At the same time,the fracture opening variable equation based on the transfer matrix algorithm is derived,and the simplified fracture group considering the grout splitting and grouting between the rock masses is further established.Rock mass model,through the addition of resistance to simulate the energy loss of grout splitting and spreading in the rock mass,which can completely describe the continuous diffusion process of grout in the fractures and between the rock masses,and establish a theoretical model of grout diffusion based on the transfer matrix method.In order to check the accuracy of the theoretical models of the above models,the transfer matrix algorithm and fluid calculation equations were embedded in the finite element software Comsol,and experimental studies on single fractures and simplified fractured rock mass groups were carried out,which finally verified the correctness of the theory;Secondly,the above simplified fracture group rock mass theory was applied to fractured rock mass slope grouting engineering.On the basis of studying the diffusion mechanism of a single group of fractured grout,the above theoretical formula was embedded in the discrete element analysis software UDEC to establish two groups The single-hole grouting model for rock fissures of the main fissures was established,the orthogonal test group was established to analyze the influence of magma parameters on the slurry diffusion,and the slurry diffusion radius formula in the two main fissures working conditions was fitted;Finally,in order to get closer to the actual grouting conditions,a porous grouting model is established,and the optimal hole spacing and optimal grouting sequence for grouting under the conditions of multiple rows of holes are found through a combination of theoretical analysis and numerical simulation.Grouting has guiding significance.