Southern Saline Soil Subgrade Salt-liquid-experimental Study Of The Deformation Temperatuer Under Field Conditions

For the southern border of saline soil, the typical problems in solution of road frostheave and frost boil, in southern Xin jiang Alar city as the basis, from the change of saline soilsubgrade structure control method of saline soil subgrade salt expansion, collapsibility andother diseases into consideration, proposed a new form of saline soil subgrade structure underthe lateral septal sparse, saline soil on the study area sampling and determination of basicparameters of water content, density, particle size and thermal conductivity, permeabilitycoefficient, frost heave test experiment by preparing soil samples; through the indoor modelexperiment of subgrade structure of small, hydrophobic layer on the two different forms ofslope and makes a comparative analysis on the "side by Shu" type of subgrade structure,hydrophobic layer and the separation layer how to set up the salt heaving disease of saline soilsubgrade can be reduced; and the "side by sparse type structure of subgrade application isanalyzed, with the city in Alar City Road Reconstruction Project for the field test and bymonitoring the deformation of the physical and mechanical properties of subgrade theconclusion is as follows:(1) the formation of frozen soil in the subgrade has a great influence on the migration ofwater and salt in the soil, and then affects the distribution of salt in saline soil subgrade..(2) sample permeability coefficient with dry density decreases gradually tends to be aconstant, along with the increase of the density, the gaps between soil particles decreases,hindering the penetration, the different gradation of soil and the relationship betweenpermeability coefficient is relatively complex. When the dry density is bigger, thepermeability coefficient decreases with the increase of the degree of compaction; in smallerdry density under, permeability coefficient increases with the increase of the degree ofcompaction increases, non-uniform coefficient is10, the permeability coefficient is up to itsmaximum value and increases with the increase of the density increases.(3) the thermal conductivity of sample has an effect of moisture content, salt content anddry density, the coefficient of thermal conductivity of the influence of the maximum saltcontent, followed by water content, dry density on the thermal conductivity of relativelyminimal impact. The heat conduction coefficient decreases with the increase of dry densityand moisture content, and increases with the increase of salt content..(4) For soil samples no salt, as the temperature decreases only occurs frost heave, theoverall amount of deformation occurs alone frost heaving deformation of relatively flat after ablation almost recovered to its original state; and when the saline soils occur salt when thefrost heave, as time increases, the amount of deformation showing a regular increase in thestate, there will be a time after the ablation of residual deformation.(5) small model tests are set in different slope of the partition layer partition layerinclination can effectively speed up the removal of salt, also can increase the salt excretion,improve the effect of salt drainage; V type partition layer, point of view is not the effect ofbetter, but a critical value for10to15degrees; DV type partition layer, the effect is is moreand more obvious with increasing of angle, and finally determine the partition layer angle10degrees for the best angle.(6) side separate hydrophobic type roadbed structure due to the partition layer, partitionforest water into the roadbed frozen soil, reduce the effect of temperature on water and saltmigration in the external temperature changes; side separate hydrophobic type roadbedstructure due to divert layer can divert a part of subgrade internal moisture to prevent capillarywater rise to permafrost, pan salt inhibition of subgrade surface, reducing the subgrade surfaceof frost heave and salt expansion deformation.(7) field test is a self balancing period, roadbed protection superiority of salt expansionalso need long-term testing, analysis, roadbed temperature has better gradient and deformationon both sides of the road to severe distortion than that of in the middle of the road.