Abstract: In order to make clear the relationship among the piles, slab and soil, the pile-slab structure vertical stepped loading and horizontal loading tests under different conditions are carried out, based on the similarity theory, such as different spans, with or without soil supporting under the slab and so on. Systematical study is made on the pile-slab-soil interaction mechanical characteristics of pile-slab structure. Some conclusions are preliminarily drawn as follows. (1) Slab-soil interaction has obvious effects on the force of the pile-slab structure. When ignoring the soil supporting under the slab, the deflection of the slab, the stress, the force of the pile and the slab-soil contact pressure will have a significant increase; and the greater the span is, the more obvious the influence will be. From this we can know that, it is conservative for engineering design that without considering the soil supporting under the slab. Therefore, it is recommended that the design of pile-slab structure should consider the supporting of the subgrade soil. (2) The pile-soil interaction is obvious under horizontal loads, and the influence areas mainly within the range of 1/2 of the pile upper part. The test also shows that the slab span has a little influence on the pile-soil interaction, but has greater impact on the lateral deflection of the slab; and the greater the span of pile-slab structure is, the larger the bending tensile stress of slab under lateral force will be. It is recommended to check the tensile stress indicators of the slab under horizontal loading during span design of pile-slab structure.

Key words: pile-slab structure, pile-slab-soil interaction, model test, vertical stepped loading, horizontal loading