Research On The Elastic-Plastic Constitutive Relation Of Loess Considering Structure

Structure is one of the intrinsic characteristics of soil, moreover, it is a basic factor that determines the mechanics behavior of soil. However, the reason that the soil forms is complicate, so it causes extremely strong distinction and an obvious regionality, and the structure of soil is various. Adopting the method of the macroscopical mechanics behavior that is described to have series of laboratory tests to the loess of Lanzhou area , and the structure of loess is analyzed and researched in order that one constitutive model of loess that can reflect the structure of loess is set up.At first, based on Xie Dingyi's ,Shao Shengjun's etc research approaches to soil's structure, the variation regularity of the structural parameter is analyzed and summarized through the compression test, consolidation test, triaxial shear test on undisturbed loess, remolded loess, saturation loess of Lanzhou area. Furthermore, based on above work, a new index m that can demonstrate the structural release in soil and the variation regularity of the index and its influence factor(axial strain,humidity, confining pressure) is drown up, at the same time the relation of the structural release in soil and its influence factor is obtained.Secondly, based on the thinking of Shen Zhujiang's theory who regards the distorting soil as two mixture of material soil: undisturbed soil andremolded soil and uses a duplex-spring model to describe the stress of the two share, the index m of the structural release of soil is imported and a new kind of constitutive model is proposed to estimate the stress-strain relationship considering structure.Finally, the relevant research aiming at the structural model of soil had been looked forwardThe work of the article is a new way on the structural model of loess and its practical application.