Study On Slope Protection Soil Improvement And Permeability Plain Reservoir

In recent years,the country has been accelerating the construction of water conservancy infrastructure.The plain reservoirs in the north have become one of the effective ways to regulate and control water resources,and construction efforts have increased year by year.The geological conditions of the plain reservoir belong to the quaternary alluvial strata.The dam earth material is mostly sand clay.Under long-term water erosion,it may cause serious consequences of seepage and damming,and soil salinization.Permeability plays a crucial role in the risk assessment of plain reservoirs.It is imperative to improve the impermeability of plain reservoirs.In this paper,the imperfections of plain reservoirs with high soil permeability are studied.The plain reservoir silty clay is taken as the research object,and four kinds of curing agent,cement,age,and dry density are studied by means of indoor penetration test,mercury injection test,and scanning electron microscope test.Under the influence of factors,the laws of soil permeability change in plain reservoirs and the combination of macroscopic physical properties and microscopic pore distribution provide a theoretical basis for further study of the seepage safety system of plain reservoirs.First of all,we should understand theoretically the regulatory requirements for safe operation of the project;we should be familiar with the experimental principles and specific operational procedures of indoor penetration test,mercury injection test,and scanning electron microscope test to ensure the scientificity and accuracy of the test results;and the clear modifiers?curing agent?cement?microscopic composition,the use of data analysis software,and the interaction mechanism between modifiers and soil particles are analyzed;then,based on the results of the previous research group,the scope of the four factors is determined.Orthogonal experiment L₁₆?4⁴?was designed to analyze the influence degree of each factor on the soil permeability of plain reservoir and determine the optimal ratio.In order to study the influence of various factors on the microscopic mechanism of soil infiltration,based on the orthogonal test results,a single factor test was designed.The pore characteristics of the improved soil were analyzed by mercury intrusion test,and the microscopic pore morphology of the soil was quantified to clarify the improvement of various factors.The effect of soil pore distribution;microscopic scanning of the improved soil by electron microscopy,visually revealing the internal phase composition and reaction products of the modified soil,and ascertaining the influence of various factors on the improvement of soil microscopic appearance.The test results show that the factors such as cement,solidifying agent and age make the permeability coefficient of plain reservoir soil reduced by one order of magnitude at natural density,increase the number of minimal porosity and micropores,decrease the number of large and medium pores,and under microscopic view,soil The tightness and tightness between the particle groups meets the requirements of anti-seepage technology.The Al³⁺curing agent and the ordinary portland cement have an inhibitory effect.The free aluminum ions in the curing agent accumulate around the calcium aluminate hydrant to form a dense protective film and prevent further hydration reaction.When the blending amount is 13%and the curing agent content is 2%,the mutual inhibition effect is large.At this time,the amount of large,medium and large pores in the improved soil was relatively small?4.63%?,the inter-particle mosaic effect was obvious,the structure was denser,and the electron microscope image was a stable clot-like structure.Cement content has a great influence on soil permeability and small pore content.The more the amount of cement,the smaller the soil permeability coefficient;when the curing age is from 7d to 28d,the clay piece transitions from a clot-like to a leaf-like shape.Mainly surface contact,hydration reaction tends to be stable.Through the multiple nonlinear regression analysis between the permeability coefficient and the porosity of macropores and mesopores,the regression equation was obtained.The improvement of the soil permeability coefficient can be used to calculate the internal pore morphology,which has practical significance in the evaluation of the seepage safety of plain reservoirs.