Dynamic pore water pressure of submerged backfill on caisson quay walls: 1 g shake table tests

摘要

This paper aims to investigate dynamic pore water pressure of submerged backfill on caisson quay walls implementing 1 g shake table physical model tests. The tests were performed on physical models instrumented with various types of transducers to record different aspects of the behavior of the quay walls and the backfill soil during shaking. The results showed that dynamic pore water pressures exerted on the quay walls were influenced by several parameters including relative density and permeability of the backfill, amplitude of base shaking, generation of excess pore water pressure in the backfill and lateral displacement of the quay wall. A comparison between the experimental results and the available analytical solutions demonstrated that the analytical solutions cannot accurately predict dynamic pore water pressures in backfills of intermediate permeability where soil-water interaction is substantial. Also, it was found that in the worst-case scenario, two out of three different dynamic thrusts exerted on the quay wall including active dynamic pressure of the backfill, dynamic pore water pressure and hydrodynamic pressure were in phase. Moreover, the variation of each of these pressures with depth was not necessarily in phase.