The invention provides a sampling device for
geotechnical engineering investigation, which comprises a box body, a sampling
drill bit, a driving mechanism, a depth measuring mechanism and a water suction pump, the box body is divided into a working cavity and a sampling cavity, and the depth measuring mechanism comprises an annular plate, a transmitting
pipe and a receiving
pipe; before sampling,the depth of to-be-sampled soil is judged according to a to-be-constructed
geotechnical engineering structure, after the device body is moved to a to-be-sampled area, water in the sampling cavity is pumped away through the water pump, then the driving mechanism drives the sampling
drill bit to be inserted into the soil, and the annular plate arranged on the outer wall of the sampling
drill bit canbe blocked on the surface of the soil; the distance between a transmitting tube and the receiving tube is increased, the height between the annular plate and the
soil surface can be obtained according to the
infrared light transmitting time of the transmitting tube and the
infrared light receiving time of the receiving tube, and therefore the depth of the sampling
drill bit inserted into soil canbe obtained, and sampling can be conducted after the sampling
drill bit reaches the preset depth. And the sampled soil sample can correctly reflect the properties of the base layer.