Parameter Study of a New Strut-and-Tie Model for a Thick Cap with Six Piles

Abstract

A comprehensive strut-and-tie model is a function of the nodes, struts, ties, model types, and pile reaction force. Because each element has more than one solution, the function is a problem of permutations and combinations. This paper presents a new strut-and-tie model that yields a satisfactory simulation result. In the model, a model type of truss action, direct arch action, or a combination of both actions was selected independently for the side and angle piles. The node and tie parameters were also modified. The pile reaction force distribution and the failure mechanism for inclined struts were also considered. However, because the authors’ previous study did not include a detailed analysis or an in-depth exploration, the effect of these critical factors is discussed in this paper at length. The model, which was programmed using the MATLAB language, was used to sequentially analyze the possible solutions for each member (nodes, ties, and struts). Different solutions for the ratio of truss action and direct arch action were also compared. The inclined struts with variable cross sections were tested under various failure mechanisms. Furthermore, the effect of the pile reaction force, which was distributed using model test measurements and theoretical (elastic or rigid) analyses, was analyzed. Comparison of the solutions indicated that the function f, which included the essential elements described above, was both rational and accurate.