The variation of porewater pressure and its relationship with liquefaction and densification in saturated sand under impact loading

In this paper, experimental set up and pressure measurement system for studying the response of saturated sand to impact are introduced. After the dropping saturated sand column strikes the ground, the variation of porewater pressure with time is measured. It consists of two stages, i.e., quick variation in early stage and slow variation in late stage. For the early stage, the propagation of impact presssure wave profiles and its relationship with drop height and measuring position are given. For the late stage, the variation of excess porewater pressure with drop height, sand sample, measuring position and its relationship with liquefaction and densification of saturated sand are discussed.