Extended Finite Layer Method for Semi-space Ground Analysis

The layered nature of natural soil must be considered in ground engineering. To this end, a ground finite layer method (FLM) based on extended patterns is proposed on the basis of the principles of traditional FLM. First, the displacement mode of the layer element uses the multiplication form of a quintic fully polynomial and double series. By superposing the calculated solutions of four symmetric loading patterns, the extended FLM can be used to analyze the mechanical state of ground under various types of loads. Second, the selection principles and methods for some important parameters of the extended FLM are established by analyzing and discussing the stress and displacement characteristics of ground loaded with vertical unit force. Finally, after a comparison with the solutions of classical analytical methods, such as the Boussinesq, Mindlin, and Cerruti formulae, the extended FLM is verified to be rational and accurate outside of the loading influence range. Thus, the proposed method will be easier to use in practice due to its adaptability to layered ground; however, its scope of influence and its mechanism near the loading position require further research.