Experimental study on resistance of pull-out cone penetration tests

To investigate change of resistance of pull-out cone penetration tests, pull-out tests are performed on clayey soil and sand in a new large-scale model chamber under controlled conditions. The effects of edge angle, edge length, pull-out rate, compactness and relative densities on the evolution of pull-out resistance are highlighted. The results show that the change of pull-out resistance can be divided into three stages: sharp-increases stage, slow-increase stage and stabilization. The pull-out resistance increases along with the increase of edge angle. The increasing rate of pull-out resistance at early stage of tests and the ultimate value of pull-out resistance become larger and larger as the increase of edge length. The pull-out resistance and its maximum value also increases as the increase of pull-out rate, compactness and relative densities. However, there is no obviously linear relationship between the maximum pull-out resistance and the compactness. The increase of pull-out resistance is slow at low compactness and relative densities while it is fast when the compactness and relative densities become large.