A kind of sample preparation method of cylindrical soil sample for cohesive soil tensile strength experiment

Abstract

The invention discloses a sample preparation method of a cylindrical soil sample for a cohesive soil tensile strength experiment. Three layers of cohesive soil are filled in a mold in the axial direction of the cylindrical soil sample, and each layer is compacted after filling; at the same time, the end strength of each layer is strengthened by a method for inserting reinforcing ribs at the end ofeach layer of the soil sample, so that the layered contact surface of the soil sample is parallel to a direction in which a tensile force is applied. According to the method provided by the invention, by strengthening the end strength of the sample and eliminating the strength defect of the sample in a tensile direction, the goal that the sample is destroyed in a tensile stress distribution areato obtain a real value of the tensile strength of the soil sample is achieved.

Description

technical field [0001] The invention discloses a method for preparing a cylindrical soil sample for the tensile strength test of cohesive soil. Background technique [0002] The method for making clay samples in conventional triaxial tensile tests is to fill in parallel layers (5 layers), that is, the direction of the applied tension is perpendicular to the contact surface of the soil layers (such as figure 1 ). There are three shortcomings. First, the bonding force of the contact surface between the layers is weak and easy to pull apart; second, when filling, the layer is compacted, and the lower layer has a large compaction work and a high degree of compaction, resulting in uneven distribution of soil strength; Third, the shrinkage trend of the sample under the action of tension is limited near both ends of the sample. In addition to the action of tension, it is also affected by shear force, which is a complex stress area, not a strict tension state. Therefore, when the ...

AI Technical Summary

Problems solved by technology

There are three shortcomings. First, the bonding force of the contact surface between the layers is weak and easy to pull apart; second, when filling, the layer is compacted, and the lower layer has a large compaction work and a high degree of compaction, resulting in uneven distribution of soil strength; Third, the shrinkage trend of the sample under the action of tension is limited near both ends of the sample. In addition to the action of tension, it is also subjected to shear force, which is a complex stress area, not a strict tension state.

Therefore, the data measured under this method cannot represent the true tensile strength of the sample

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