Study On The Influence Of One-dimensional Vertical Infiltration Of Muddy Water On The Formation Characteristics And Infiltration Law Of Tight Layer

In this paper,based on the existing research on muddy water infiltration,through the indoor one-dimensional vertical muddy water infiltration test,the muddy water silt rate,soil bulk density,and sediment particle gradation are the influencing factors to study the sedimentation.Effects of layer thickness,composition and content of dense layer particles,cumulative infiltration,wetting front and soil moisture distribution.The main conclusions are as follows:(1)Muddy water sediment rate,soil bulk density and sediment viscosity index all have a significant effect on the thickness of the sludge layer;during the formation of the sludge layer,it has a power function relationship with the infiltration time;at the same infiltration time,with the the increase of sand content,the decrease of soil bulk density and viscosity index,the fitting coefficient a and the fitting parameter b are gradually increased.The mathematical model of the thickness of the silt layer and the infiltration time varying with various factors is established.(2)The muddy water sediment rate,soil bulk density and sediment viscosity index all have a significant effect on the change of particle content in the retentive layer;the particle content of less than 20 ?m and the physical clay content in the silt layer all follow the sediment rate.The increase of the soil density and the decrease of the soil bulk density.At 1 cm infiltration depth,the particle content and physical clay content of less than 20 ?m increase with the increase of the sand content and the soil bulk density,2 cm at the infiltration depth,the soil particle composition does not change significantly with various factors,the particle content of the falling silt layer with a different viscosity index of less than 20 ?m and the physical clay content generally change less than the infiltration sediment,and the amount of change varies with the viscosity index the decrease gradually increases.Under different viscosity indexes,the content of particles less than 20 ?m at 1 cm infiltration depth and the content of physical clay particles increase compared with the infiltration sediment,and the amount of change gradually decreases with the decrease of the viscosity index Increase;from topsoil to infiltration depth of about 1 cm can be used as a retention layer.(3)The cumulative infiltration volume per unit area is obviously affected by the muddy water sediment rate,soil bulk density and sediment viscosity index;under various factors,the cumulative infiltration volume per unit area changes with time in line with Kostiakov infiltration model and Philip infiltration Model relationship;with the increase of muddy water sediment rate and soil bulk density and decrease of viscosity index,the infiltration fitting coefficient e,infiltration fitting parameter f and soil infiltration rate S all decrease;(4)Muddy water sediment rate,soil bulk density and sediment viscosity index all have a great influence on the wet front;for different influencing factors,the wet front changes with infiltration time is a power function relationship;the wet front fitting coefficient p It increases with the increase of muddy water sediment rate,soil bulk density and decrease of viscosity index;the wetting front fitting parameter q decreases with the increase of muddy water sediment rate and decrease of viscosity index,and with the soil bulk density Increase.(5)All factors have a significant effect on the distribution of soil moisture content after the infiltration;at the infiltration depth of 5 cm,the soil moisture content at different levels of each factor is close to the saturation moisture content,the same factor treatment differences at different levels Smaller;at the same infiltration depth,with the increase of muddy water sand content and soil bulk density and decrease of viscosity index,soil moisture content gradually increased.(6)Under different sediment rates,the infiltration rate changes with the generalized wetting front average suction reciprocal value curve is basically compared to a point,and the value is very close to the soil saturated hydraulic conductivity value;the soil infiltration rate and generalized wetting The slope of the relationship curve of the average suction reciprocal at the front gradually decreases with the increase of the sand content,indicating that the average average suction value decreases with the increase of the sand content;And analysis shows that the muddy water infiltration model is correct and can be used to study muddy water infiltration problems with different sand content.A Green-Ampt infiltration model including muddy water sand content and viscosity index is obtained.