In Table 1, PI is the plasticity index and w n the natural water content.
Furthermore, what is meant by Special Soils are soils having high liquefaction
potentials, very sensitive clays, soft clays with a total thickness of 3 m or more,
loosely cemented sands, peat, soils containing organic materials with a thickness of
more than 3 m, and very soft clays with a plasticity index of more than 75 and a
thickness of more than 30 m. For these Special Soils the peak ground acceleration
must be obtained from the result of a seismic wave propagation analysis.
For the soil categories defined in Table 1, the peak ground acceleration A o for
each seismic zone is shown in Table 2.