Additional stress distribution behavior of T-shaped deep mixed column composite foundation under embankment load

Three-dimensional finite difference method was used to establish the numerical model of T-shaped deep mixed column composite foundation. Then, the influence of the design parameters of T-shaped deep mixed column composite foundation on additional stress distribution was analyzed. Based on the additional stress distribution behavior of the foundation, considering stress concentration phenomenon, a calculated model was proposed to calculate additional stress in substratum of composite foundation under embankment load. The results indicate that the column effect slows down the distribution of the additional stress in composite foundation. The additional stress in the middle of road in improved area of composite foundation is lower than that of natural foundation at the same depth, while the additional stress in substratum of composite foundation is larger than that of natural foundation. The enlarged column cap height, enlarged column cap diameter, column length, column spacing and column modulus are the main parameters which effect the additional stress distribution behavior of T-shaped deep mixed column composite foundation under embankment load. The proposed calculated model of additional stress in substratum of composite foundation is more efficiently than conventional model.