| Nowadays,the problem of serious shortage of water resources is becoming more and more serious.By studying the combination of heterogeneous filter material with sand free concrete slab in different ratio to carry out seepage water intake and drainage,the change of seepage flow can be effectively controlled,so as to improve the utilization rate of water resources and reduce the impact of water resource waste from various aspects.In porous medium is used in practical engineering by permeable layer composed of complex medium permeability function,this paper takes"sponge city"construction and"Xin An Quan water project"in Shanxi Province as a selected topic background,the physical model test and theoretical analysis,the method of combining with head pressure,particle size of the filter material and different aspects such as filter material mix proportion as control variable,the heterogeneous filter material without sand concrete slab under the influence of permeability is studied.The conclusions are as follows:(1)The relation equation of seepage rate and pressure water head under the condition of no sand concrete slab without filling is constructed.Without any filter material filling,simply use a sand concrete board as a permeable medium,the seepage flow and pressure head as power function relationship,and the greater the pressure head,the greater the seepage flow without sand concrete slab,at the same time,according to the hydraulic gradient,and the fitting between the seepage flow equation,the sand concrete plate inside the flow regime transition from laminar to turbulent flow.(2)The influence mechanism of heterogeneous filter material on the seepage characteristics of sand free concrete slab is expounded.Without sand concrete slab laid on two different kinds of particle filter material mixing ratio of porous medium and three kinds of particle filter,a mix of different ratio of porous media,and analyses the influence of pressure head heterogeneity of sand filter material and concrete slab seepage influence of seepage flow of the system,and the results show that the seepage flow and the pressure head is still a positive relationship,according to the different mixing ratio of heterogeneous seepage box filter material in the average particle size,the greater the its seepage flow.For the experimental conditions studied in this paper,the flow pattern is a transition zone from laminar flow to turbulent flow.At the same time,the empirical formula of daily seepage flow yield and working head per square meter under each working condition is obtained through calculation.(3)Through dimensional analysis and combined with MATLAB software nlinfit function obtained the heterogeneity in the filter material without sand concrete slab under the influence of seepage flow of the empirical formula of(?),and is verified by test,find the maximum relative error is 12.4%,that the empirical formula of the seepage flow is correct,is feasible in practical application,can be applied to heterogeneous liao no sand concrete slab under the influence of seepage flow calculation.(4)Using SPSS software and standard coefficient of regression analysis,respectively for heterogeneous filter material without sand concrete slab seepage characteristics under the influence of affecting factors are analyzed,based on the analysis of heterogeneous filter material without sand concrete slab under the influence of seepage flow and the pressure head and heterogeneity the correlation of the average particle size of filter material,finally determine the pressure head and heterogeneity of filter material the influence degree of the average particle size of seepage flow is:the pressure head to the influence of seepage flow is greater than the average particle size of filter material effect on the seepage flow.The research results of this paper can provide a theoretical basis for the study on the influence of heterogeneous filter material on the seepage characteristics of sandless concrete slab,and also provide a certain reference value for the actual seepage water intake project of water conservancy. |
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