Shelby Tubes And Thin Walled Sampler

They are generally used to take undisturbed samples for routine site investigation works.

Shelby tubes and thin walled sampler.

However the tube should not be driven beyond 90 per cent of its total length. This sampler should be forced into the soil by pressing under steady pressure in order to take sample. Typical sizes of thin walled tubes are shown on table 1 the most commonly used tube is the 3 in. The system is used to sample soils that are particularly sensitive to sampling disturbance as it has a very low wall thickness to sample area ratio.

2 shows the use of the sampler in a drill hole. The bottom of the tube is sharpened and beveled which acts as a cutting edge. Shelby tube samplers are thin walled hollow steel tubes which are driven into the ground to extract a relatively undisturbed soil sample for use in laboratory tests used to determine density permeability compressibility and strength. Thin walled open tube samplers are designed for taking samples in soft and firm cohesive soils.

The tube is pushed driven into the soil. The shelby sampler is a thin walled soil sampling system. The clear sketch of shelby tube is shown in fig 2 6 a. 5 1 thin walled tube samples are used for obtaining intact specimens of fine grained soils for laboratory tests to determine engineering properties of soils strength compressibility permeability and density.

The upper portion of the sampler has threads on the inside surface to enable the sampler to be attached to the bottom of the drill rod. They are thin wall tube samplers made of seamless steel and are also known as thin wall shelby tube samplers. Two factors which are essential for evaluating engineering properties. These samplers have a much lower area ratio approximately 10 than u100 samplers and therefore give less disturbed samples.

The thin walled seamless steel tubes are called shelby tubes. Shelby tube sampling methods are used to collect undisturbed samples of soft fine grained cohesive soils in an effort to recover intact samples which are representative of the in situ soil density and water content. The thin steel tube may be removed from the sampler to be used as a container to transport the sample minimising disturbance preserving moisture and reducing delays in the sampling procedure. However some disturbance is caused due to friction of the sample on the inside of the sample tube.

Shelby tube sampler is utilized in the standard practice for thin walled tube sampling of soils for geotechnical purposes used for sampling undisturbed samples of cohesive silts and soft clays. They are suitable for fine soils up to a firm consistency and free from large particles. The sampler consists of a thin walled steel tube whose lower end is shaped to form a cutting edge. Shelby tube sampler thin wall open tube samplers shelby tube samplers are used for soils that are particularly sensitive to sampling disturbance.

Thin walled shelby tube sample.