I saw this vibracoring on uTube- might work for you. https://m.youtube.com/watch?v=xezcS2moPgQ

About 10foot A frame, concrete vibrator attachment, people power, come along to-remove. Sample in what appeared to be geologist or well drillers coring pipe. Generally, sampling soils to that depth would probably be best if wet. Rocks can be a problem.

Dear Guillem

Greetings

The ergonomic hand auger set for heterogeneous soils is used to carry out manual drilling and sampling in a great variety of different soils. It is particularly suitable for general soil investigation as well as taking samples for such activities as environmental research. It can carry out drillings to a depth of 5 meters, depending on the build-up of the soil and the nature of the material to be drilled into.

You can buy this sampler from the following website:

https://en.eijkelkamp.com/login/?blink=/products/augering-soil-sampling-equipment/Ergonomical-auger-set.html

I also have attached a pdf file about this sampler. please find it.

Finger crossed

Bijan

Samples were taken from the site by means of a number of site probes to determine the nature of the soil and the properties of its layers.

* Drilling: - The probes are the drilling of a floor in the site to be explored in different depths through which soil samples can be obtained to identify the quality and arrangement of the substrates. Drilling can be carried out either manually or by other mechanical equipment. Guillem Llorens-Blanch

The file sent could be used for taking disturbed soil samples.