Device and method for rapidly measuring suction and shear strength of unsaturated soil matrix

Abstract

The invention discloses a device and a method for rapidly measuring suction and shear strength of an unsaturated soil matrix. The device comprises a centrifugal machine cabin, a thread cutting workbench, a pressurizing system, a pressure sensor, a breathable pressure applying cover, a shearing box, a drainage collecting box, a ball, a sliding way, a shearing force applying system, a shearing forcesensor and a displacement sensor, wherein the shearing box is connected with the drainage collecting box and makes contact with a sliding way of the thread cutting workbench through the ball, the pressurizing system is installed at the axis of the cabin, and pressure acts on the sample through a breathable pressure cover, the shearing force applying system is mounted at the bottom of the centrifugal machine cabin, shearing force vertically acts on the lower shearing box upwards, and force and displacement values are collected through the pressure sensor, the shearing force sensor and the displacement sensor. The method comprises the following steps of preparing a sample, installing a sample, matrix suction measurement, unsaturated strength measurement and moisture content measurement. Thedevice is advantaged in that rapid measurement of unsaturated sample matrix suction and unsaturated strength can be realized, and the device is of great significance to research of unsaturated soil.

Description

technical field [0001] The invention belongs to the technical field of unsaturated soil mechanics experiments, in particular to a device and method for quickly measuring the suction force and shear strength of unsaturated soil matrix. Background technique [0002] Most of the soils touched by human engineering activities are unsaturated soils. How to quickly obtain the matric suction and unsaturated strength of soils is an urgent problem to be solved. At present, there are filter paper method, axial translation method and tensiometer method for measuring matrix suction. Although these methods can measure the size of soil matrix suction, the measurement period ranges from 7 to 30 days, or even longer. Generally, 6-8 data points are needed to draw a soil and water characteristic curve, and the time required is doubled. At present, the instruments commonly used to measure the unsaturated strength of soil are unsaturated direct shear instrument, unsaturated triaxial instrument ...

AI Technical Summary

Problems solved by technology

The use of the above instruments will greatly reduce the test efficiency, prolong the scientific research and engineering cycle, and cause waste of resources and economy

[0003] At present, unsaturated soil capillary suction direct shear instrument and its use method (CN108956331A), automatic direct shear instrument (CN109211687A) for the study of unsaturated shear properties of high compacted bentonite, unsaturated soil evaporative dehumidification direct shear instrument and its use Method (CN108693049A), the measuring method of unsaturated soil shear strength parameter and special direct shear instrument (CN107389473A) etc., although these methods can be to the measurement of unsaturated soil matrix suction and unsaturated strength, test efficiency is low, needs It takes a lot of time, and its application in scientific research and engineering is greatly limited

For a patented method for measuring the suction of unsaturated soil matrix in a centrifugal model test (CN110568151A), the unsaturated data measured in this patent is single and the steps are numerous, which causes waste of resources to a certain extent

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