Quaternary period sediment in north side of the Yangtze River estuary (Nantong-Qidong reach) is evaluated by physical property indexes; it has poor properties and belongs to soft soil according to the soil classification system. But evaluated by mechanical properties indexes (a1-2

Es1-2

CPT

SPT etc)

the soil has good properties. So it is not all consistent between physical properties indexes and mechanical properties indexes. The phenomenon is analyzed that physical property is poor but mechanical property is good. Now some

new indexes evaluating engineering characteristics of the soil are proposed to solve the inconsistency between physical properties and engineering properties.