Abstract: It is of great significance to study the shear behavior of the structure-soil interface for foundation engineering design and construction. With the improved direct shear apparatus, considering the interface type and the soil water content, the direct shear tests of interface between steel and low liquid limit clay were performed, and the rate of shear, stress strain relationship and the volume change were analyzed. The results show that the shear stress presents three stages; namely, fast increase, slow increase and maintain stability, with the shear displacement. The relationship between the shear stress and the shear displacement can be expressed by the Gompertz model. When the soil mass is at the optimum water content, the interface shear strength and the index are the largest. The shear strength and the index of the rough interface are larger than those of the smooth interface. The shear shrinkage of the soil under the rough interface is more obvious than that under the smooth interface. The shear shrinkage characteristics of the soil become more significant with the water content.

Key words: Steel, Low Liquid Limit Clay, Water Content, Roughness, Rate of Shear, Stress Strain Relationship, Volume Change