Question

Difference between disturbed and undisturbed soil sample

Answer 1

Undisturbed Soil Samples

Undisturbed soil samples retain the structural integrity of the in-situ soil and have a high recovery rate within the sampler. Collecting a perfectly undisturbed sample is difficult and the samplers may contain a small portion of undisturbed soil at the top and bottom of the sample length. Undisturbed samples allow an engineer to determine the geotechnical properties of strength, permeability, compressibility and fracture patterns among others. Results of these analyses are instrumental in the design of a new building.Undisturbed Soil Collect Disturbed Soil Samples

There are a variety of methods for collecting disturbed soil samples. Basic methods include using a backhoe to create a test pit where you collect soil from the bucket or using hand augers to collect a sample from a vertical boring. You can use drill rigs to collect disturbed samples from great depths. Collection tools such as split-spoon samplers, Shelby tubes and macrocore push samplers are used in conjunction with the drill rig or a direct-push rig to collect the sample after the rig reaches the desired depth.

Answer 2

Disturbed Soil Samples

Disturbed soil samples do not retain the in-situ properties of the soil during the collection process. Engineers do not consider these samples to be representative of underground soils except for geotechnical testing that do not rely on the structure of the soil itself. Scientists commonly test disturbed soil samples for soil type and texture, moisture content, and nutrient and contaminant analysis, among other evaluations. The majority of soil samples engineers and geologists collect are disturbed samples because they are easier to collect and the precision needed to collect an undisturbed sample is not required for most geotechnical testing.

Undisturbed Soil Samples

Undisturbed soil samples retain the structural integrity of the soil and have a high recovery rate within the sampler. Collecting a perfectly undisturbed sample is difficult and the samplers may contain a small portion of undisturbed soil at the top and bottom of the sample length. Undisturbed samples allow an engineer to determine the geotechnical properties of strength, permeability, compressibility and fracture patterns among others. Results of these analyses are instrumental in the design of a new building.