Study On Mechanical Properties Of Interface Between Soil And Structure

Studying the mechanical properties of soil-structure interface is an important topic for the civil engineering and geotechnical engineering, which determines the interaction between soil and structures. The researches are more difficult because it is related to many problems of soli mechanics and foundation engineering. The deformations of these two materials are not consistent due to the physical and mechanical properties of these two materials are different, so the shear stress on the interface between the two materials are large. Usually, the contact and resulting relative sliding or cracking are simulated by setting interface elements between these two materials for the finite element calculation. Selecting appropriate interface elements and studying the mechanical properties of interface are important to the analysis of interaction between the soil and structure. The concrete works are:(1) the testing instruments of interfaces as well as the studying results at home and abroad are introduced.(2) The reasonable value range of modal parameters are studied by mathematical model test. The normal stiffness of interface element are 50 to 100 elastic modulus. The approximate relations of normal stiffness and initial shear stiffness are Kn=2.5Ks(3) The sensitivity of major parameters of the static-dynamic constitutive modal of interface elements are analysed for the face rockfill dams whose height are 100m,200m and 300m. the conclusions are that, for the static, the stress along slope will increase with the increasing static parameters of k andφ, and the effects of (p are more obvious. The effects to the dams of 100m are larger than the others. The effects in the time of completion are more obvious than the storage periods. For the dynamic, the synamic-static superposed compressive stresses along slope will increase at first then decrease with the increasing height of dams and the maximum value are produced at 0.6 heights of dam. The maximum tensile stress are at the bottom of dam and the value are not big. The static-dynamic superposed stress increases with the increasing dynamic parameters of C andφ, and it decreases with the increasing parameter of M. The effects of C are the most obvious. The effects to the low dam are more obvious than the high dam.(4) For the dam of 300m, the static-dynamic analysises are compared by setting no contact element and Goodman element with no thickness as well as specific thin layer element. The results are that, when there are no interface element between the panel and the rockfill, the minimum stress and the maximum stress are 40% and 22% larger than that which are setting Goodman element respectively. The stress of panel will decreases by setting thin layer element and Goodman element, and the distribution lawsare the same. The results of stress along slope of panel using thin layer element are bigger than the results using Goodman element. The stress of panel along slope will be decreased by decreasing the parameters of shear stiffness such as k and n.