| Reinforced concrete pile caps are typically calculated and designed based on the theories of beam and slab. Recent research literatures show a promising trend of using strut-and-tie modeling for the analysis of RC pile caps. The main works are summarized as follows:(1) This thesis firstly describes the design methods of the pile cap in different design codes. The research achievement and trend in this field are also reviewed. Some problems are discussed when the strut-and-tie theory is used in the pile cap design. After describing the strut, tie, node and the angle limit between strut and tie, member strength regulations in differnent codes are classified, and the regulations for the strut and tie strength coefficient are also summarized in the form of a table.How to build a correct strut-tie model (STM) and the steps about STM design are also described followed by comments on the weakness about STM.(2) Strut and tie modeling is used for analysing the force resisting mechanisms in the RC caps of the quasi-static experimental models with concrete-filled steel tube (CFT) column, RC cap and 16 H-shaped steel piles. The STM can be used to calculate the reinforcement considering the strength of the node and strut and concrete shear strength in the stirrup effective area. The results from the STM design can be compared to the ones from the beam design. It is discoverd that the reinforcement from the STM are less than the reinforcement from the beam method.(3) A general two dimensional STM for the RC cap under horizontal load is provided. The cap is in the model which uses embeded CFT column, many piles and RC cap. The two dimensional STM diagrams are provided for 2×2 piles cap, 3×3 piles cap and 5×5 piles cap. In order to prove the rationality of provided 2D STM, the finite element model is built and the stress trajectories are obtained from the elastic analysis. The results from the finite element analysis proves the correctness of the STM.
|
PDF Full Text Request