The Research On The Influence Of Subgrade Character Due To Moisture Migration

With the continuous development of road construction, road diseases reduces the ridingsafety, affect the road comfort and reduce road service life.Especially in the rainy season,rainwater affect the physical traits of roadbed due to infiltration, and caused the water damageof road under the influence of road traffic load. It has become a prominent topic that how tosolve the problem of road water damage fundamentally.As to the paper, firstly, I study the recearch from the aspect of the mechanical propertiesdue to the road for water transfer, then based on it I undertook the survey of the present ourcountry road destruction forms, and analysis preliminarily the forms and reasons of roaddamages.At last, I make the research direction. In order to analyze the mechanics properties ofunsaturated soil due to particle size distribution, in this paper, join the20%and40%sand tothe low liquid limit clay base, and arrange three different soil samples, and compared thedifference of various mechanical properties. I get the soil-water characteristic curve bytests.And in the curve, with increasing with the sand content rate, the soil-water characteristiccurve becomes smooth.Through the indoor model test analysis of moisture migrationregularity, and analyze the mechanical properties of unsaturated soil after the change of thesubgrade moisture. Initial moisture content influences moisture migration to large degree,after the change of the moisture content, the shearing strength of soil is reduced, cohesion isreduced, internal friction angle becomes smaller, compression coefficient increased. Withincreasing of the sand ratio, shear strength increases, friction angle increase, cohesiondecreases and compression coefficient decreases. The research results can provide theoreticalsupport to the construction of road subgrade.