Characterization of Soil Displacements During Press-in Pile Model Tests

Abstract

When a pile is pushed into the ground, it will incur displacement field in the ambient soils which will pose danger to existing structures, e.g. pipelines, foundations, and tunnels. To characterize the soil displacements caused by press-in piles, model tests combined with digital image correlation (DIC) techniques were performed. A digital camera was installed outside the model box to measure the full-field displacements. In addition to soil displacements, eight earth pressure sensors were installed to investigate soil stress in the horizontal direction during the whole process of pile installation. Based on model test results, it was found that both soil stresses and displacements in the horizontal initiated and peaked before pile tip approached. When pile tip passed the designated depths, the soil stresses went back to initial at-rest state and soil horizontal displacements stabilized. In general, soil displacements and stresses were conjugated behaviors during pile penetration. However, the conjugated relation at 3D (D is the width of model pile) distance from pile surface was less pronounced than 1D.