Design of thick pile cap with steel fiber reinforced concrete by space tie-arch analogy and truss analogy

Based on the experimental achievement and nonlinear finite element analysis result of 9 three-pile and 15 four-pile ordinary reinforced concrete and steel fiber reinforced concrete (SFRC) caps, the space tie-arch analogy and applied truss analogy of pile cap are advanced here. With the proposed formulas in Code for Design of Building Foundation and Ground (GB 50007-2002) and Specification for Design of Reinforced Concrete Pile Caps (CECS 88: 97) for reference, the formulas of the bearing capacity of bending, shearing and punching of corner piles of thick pile cap are promoted in terms of above two suggested load-transferred models. This improved method for design of SFRC pile cap considers not only the active effect of the addition of steel fibers but also the span-to-depth ratio of caps, which breaks through the traditional bending theory for design of pile cap and possesses an important applied value for design of thick pile cap in engineering.