Negative shear property of soil-concrete interface is one critical issue in civil engineering. According to negative simple shear tests of soil-concrete interfaces with various water content

quantitative analysis on changes of shear strength

friction angle and cohesion force of negative sheared interface against positive shear experience were conducted. Several empirical formulae were proposed for above changes

and critical positive shear ratio was put forward. Based on improved stress-strain equation

mathematical model for tangent modulus of negative sheared soil-concrete interface was established. This new model consists ten parameters which can be determined by simple shear test. Process for determining these ten parameters was presented

and empirical values of them were obtained. Simulations for stress-strain curves of soil-concrete interface were carried out

and good ability of the model was found.