Indoor And Outdoor Experimental Investigation Of Wetting Characters On Unsaturated Soil And Its Application

Both loading and varying percent moisture can cause deformation of soil.Wetting deformation is defined as the deformation that occur when arise the percent moisture to make the unsaturated natural soil to be saturated,while the stress state is constant.In this thesis,the soil used in tests is taken from Beijing Olympic forest park fabricating yard.We make the natural soil to dry powder,and then do a series of wetting tests.From the tests,we get some rules of wetting.The grain size can make the compression curve of dry powder to be overhead in the e-ln p chart,the less the grain size of dry powder,the more linear the compression curve will be.In e-ln p chart,the compression curve of wetting saturated soil is linear,and its slope coefficient is larger than saturated mud fluid.As the grain size of dry powder is becoming smaller before wetting,the slope coefficient of wetting saturated soil is approaching slope coefficient of saturated mud fluid.After wetting the normal consolidated dry powder at different loading,in e-ln p chart,the void ratio comes to the compression curve of wetting saturated soil whose grain size is the same as dry powder.After wetting the light over consolidated dry powder at different loading,in e-ln p chart,the void ratio comes to the compression curve of wetting saturated soil whose grain size is the same as dry powder.But when wetting the heavy over consolidated dry powder at different loading,the void ratio becomes large.And for making the conclusion more clear,in this thesis,we also do some wetting tests of sand with the same grain size of dry powder.Concluded from test results,we work out a wetting constitutive model which can calculate wetting deformation of normal consolidated and over consolidated natural soil in any stress state that the stress ratio q/p is little than critical state stress ratio M.Using this model,we predict Sun's test datas and agree them well,then we calculate an example of wetting over consolidated natural soil.