The conventional sampling techniques used in China are presented together with the effects caused by soil disturbance on the engineering design. The design and operation of a high quality continuous sampler
which can obtain undisturbed fine silty sand samples
are introduced. The operation of the continuous sampler was simulated in the laboratory. The effects of sampling on the deformation of soil
the magnitude of push-in force and the change of pore-water pressure have been studied. The results show that high quality soil samples can be obtained from the continuous sampler with high efficiency. It seems that the sampler is an important tool in surveying of strata.