First thing, we needed to know was the measurement associated with the shear box including the height and mass, as well as cross-sectional dimensions to determine the normal force. Next thing to do was preparing a 200-gr sample of dense soil so we could compact it later into the box. The extracted sample was reckoned among the well-graded sands. The soil sample was then compacted into three equal layers such that the middle layer could be placed almost at the half height of the box where shear plane has been designed to be. A general planar view of this configuration is shown in figure 1.
We used a flattening tool so we could have an even surface at top of the sample. Then, required measurements including the total weight of the box with the sand inside and the volume of the sand were recorded. By utilizing these measurements, the dry unit weight of the Ottawa Sand Specimen could be obtained. After that, the shear box assembly was ready to be tested. A metal plate was appropriately embedded on top with ridges aligned perpendicularly to the loading direction. To make sure that loading is applied vertically (as a normal force), a metal cap with a metal ball on top is used above the plate. Then, The Shear Track II Load Frame System was utilized to shear the prepared box, which was placed inside earlier, at a controlled rate. The general test setup is shown in figure 2.During the test, upper half of the box was laterally displaced while the other half was fixed in place. During shearing, the required data and graphs including parameters like shear stress and displacement were recorded and stored by the system so could be later used for assessment and analysis.
The procedure is then repeated for a loose sand sample, which was classified as a poorly-graded Ottawa sand based on grain distribution results, with one difference in compaction as the soil was poured into the box through a funnel. As the ultimate purpose of this experiment, the results obtained through these two test runs for shear strength parameters in dense and loose sand (and poorly and well graded soil) was compared.
Unconfined Compression TestProcedure
First, It was necessary to prepare the test sample. A 200-gram sample of Boston Blue Clay was extracted and then, a moisture content of 15% was achieved by adding 30 mL of water. More water was mixed in order to distribute water evenly through the sample and preventing clumping of the soil. Next, The required measurements including the diameter and height of the mold were recorded. The procedure continues by using a compacting tool in order to compacting the soil into the mold in five equal layers. The placement and compactness was such that the top of last layer almost met the top of the mold. Any excess soil on the top of the mold was cut off. A device was later used in order to extract the sample from the mold. After that, the sample was ready for the test. The unconfined compression test machine was used to extract and record the necessary data associated with compressive strength properties. The test setup for this experiment is shown figure 3.
