Study On Permeability And Mechanism Of Shaft Lining Concrete Based On Particle Flow Hydraulic Coupling Model

The construction of the shaft is the top priority of the mine construction process,the shaft is working in the environment complex underground,through the aquifer and the pressure of high ground stress and high water water pressure.If we can accurately master the change law of seepage characteristics of concrete material of shaft lining,the change law of bearing capacity of shaft lining structure and the formation mechanism of water inrush channel of shaft lining under different water pressure and confining pressure,we can provide theoretical basis for the guarantee of engineering quality during actual construction and the design of waterproofing scheme in later period.In this paper,the shaft lining model and its main material concrete as the research object,mainly through particle flow numerical calculation,explore the influence of confining pressure and pore pressure on the permeability of concrete and shaft lining bearing capacity of the two factors,and analyze the formation mechanism of the shaft lining water inrush channel.Specific results are as follows:(1)Triaxial compression and permeability tests of concrete specimens under different combinations of confining pressures of 5MPa,6MPa,7MPa and 8MPa and pore pressures of 1.0MPa,1.5MPa,2.0MPa and 2.5MPa were carried out.The results showed that:The permeability of concrete decreases first and then increases in the process of the slow increase of axial pressure,and the permeability in the low load area is the most sensitive to the change of axial pressure,and the maximum decrease reaches 95.5%.The initial permeability of concrete decreases with the increase of confining pressure,and the sensitivity of confining pressure to its permeability is at the highest level of the three loads.With the increase of pore water pressure,the effective confining pressure decreases and the initial permeability increases.(2)Particle flow simulation software was used to simulate and verify the test data,and triaxial compression stress-strain curve was calculated on this basis.The results showed that:Concrete can be in the process of triaxial compression stress-strain curve can be divided into pore pressure stage,stage of elastic deformation and crack development stage and failure stage four stages,respectively,and the permeability of concrete by the sharp drop in to leveled off to a slow recovery in the last accelerate recovery corresponding to the four development trend,and use the relevant data measuring circle around them.(3)The use of granular flow numerical simulation software of shaft under different pore water pressure loading test,the results show that the lining structure of whole stress state is influenced by the pore water pressure is small,but still can cause lining bearing capacity and the negative impact of brittle failure features obvious reason is that parts appear stress concentration phenomenon caused by crack expanding quickly.The stress concentration occurs in the crack concentration area within the scope of pore water pressure,and with the expansion of the crack,the high stress area shifts from the outside to the inside until the water inrush channel is formed.Figure 41 Table 17 Reference 78...