Finite element analysis of soil-structure interaction in soil anchor pull-out tests

This study presents new data from soil anchor field pull-out tests that were carried out on insitu ground anchor systems, using strain gauges to evaluate the changes in the variations of axial load and skin friction along the nail during the tests. The results of these field tests provide details about the development of skin friction with induced displacements, thus offering the opportunity to perform load-transfer analyses of the soil anchor. A finite element (FE) model based on the load-transfer approach is set up to analyse this problem. The nonlinear load-transfer (t-z) relation requires 3 distinct parameters to be defined, which are related to the initial soil stiffness, stiffness degradation and ultimate strength. These parameters are defined from the field test data. Subsequent FE analyses using these parameters are run to validate the new loadtransfer models which are compared with the field test results and exhibit an excellent agreement.