A direct tensile tensile strength testing device and method for soft rock and soil

Abstract

The invention discloses a direct tensile tensile strength testing device and method for soft rock and soil, and the test objects are hollow columnar soil and soft rock. The device includes a mechanical part and a control part; the computer is connected with the mechanical part through a circuit board, and the control of the mechanical part and the collection and processing of test data are completed; the test method: connect the computer and each component; pass the central hole of the sample through the tie rod The center pull column of the device is placed on the pull seat; the center pull column can be symmetrically separated into the left half pull column and the right half pull column along the axis; buckle the left and right flat rods of the pull down rod device, and adjust the position of the right pull seat to make the left and right half pull columns. The outer arc surface is attached to the inner wall of the center hole of the sample; the tensile load is provided by the stepping motor; the pressure and displacement data are collected during the test, and the tensile strength value of the sample is calculated by the computer program after the test. The invention has compact layout, light weight and easy operation; adopts a central pulling column to standardize the position and posture of the sample to ensure no bias stress during stretching; and the test result is accurate.

Description

technical field [0001] The invention relates to a direct tensile tensile strength testing device and method for soft rock and soil, and belongs to the technical field of tensile strength testing. Background technique [0002] Tensile strength refers to the ultimate resistance of materials to tensile stress generated by external loads. At present, the test methods for soil and soft rock are mainly uniaxial tension method, Brazilian split method, axial fracturing method, and soil beam bending method. Among them, the uniaxial tension method belongs to the direct test method, and the Brazilian split method, the axial fracturing method, and the soil beam bending method belong to the indirect test method. [0003] The uniaxial tension method is to apply tension directly at both ends of the sample until the sample is broken. The tensile strength is calculated from the stress and area of ​​the section at fracture. The uniaxial tensile method can observe the complete process of th...

AI Technical Summary

Problems solved by technology

However, due to the small size of the pads, it is difficult to meet the specification requirements for artificial placement, resulting in eccentric pressure when pressed

In addition, the split spacer is prone to slippage during the pressing process, which leads to the failure of the test

The fracturing effect of the sample in the axial fracturing test is not easy to control, and it is also difficult to place the upper and lower small-sized cylindrical pads in the center

The size of the sample required by the soil beam bending method is large and difficult to obtain, and it is difficult to control the fracture position of the sample in the middle position

[0005] In addition to the above-mentioned problems, the load of the current tensile strength test method is generally provided by the universal testing machine, and related parts such as fixtures, pads, liners need additional processing and customization, and the entire test system is expensive and bulky bulky, inconvenient to move

The test process requires the cooperation of multiple people, the operation is complicated and cumbersome, and the efficiency is low

There are many manual steps in the test, and the installation or placement of parts is difficult to achieve precise control, which affects the final effect of the test

Images