Design Method of Bridge Approach Improved by Deep Mixing Methods in Highway Engineering

Abstract

The deep mixing method was usually adopted to improve the thick deposited soft clay foundation in highway engineering, especially in the bridge approach section. In these projects, the uneven foundation was artificially formed which may cause the different settlement after the embankment operation. To solve this problem, there are two methods usually employed, i.e. (1) changing the column spacing and (2) changing column length, but there is not symmetric solution. In this paper, the control standard of the different slope ratio is first discussed, and then the FEM simulations of the above two methods were performed considering a lot of combination geological and highway cases. The results show that the probabilistic model based on the relationship between the maximum slope different slope ratio and the stiffness ratio and the column length ratio could overcome this problem. Finally, the empirical design methods controlling the relative stiffness ratio and the relative length ratio were proposed.