This device can be used to determine soil shear strength and residual shear parameters, providing a theoretical basis for the design and construction of slope engineering, dam construction, and foundation treatment projects.

Unsaturated Soil Dynamic Ring Shear Apparatus

Model:TGSYM-1

I.Product Introduction

This equipment utilizes a pneumatic loading mechanism to apply a vertical load to a soil sample.Under this load,the shear box of the ring shear apparatus rotates via a motor,simulating changes in the strength and properties of the soil when it slides and shifts under natural disasters such as landslides.It can be used to determine the shear strength and residual shear parameters of soil, providing a theoretical basis for the design and construction of slope engineering, embankment projects, and foundation treatment.

II.Reference Standards

ISO 17892-10:2018——Geotechnical investigation and testing—Laboratory testing of soil——Part 10:Direct shear tests

ASTM D6467—Standard Test Method for Torsional Ring Shear Test to Determine Drained Residual Shear Strength of Cohesive Soils

III.Working Mechanism

1.The servo microcomputer controller in the ring shear apparatus controls the vertical loading device,applying vertical normal stress to the top of the specimen.The vertical normal stress simulates the consolidation of the soil in the sliding zone under the action of the overlying load,thus completing the compression and consolidation process of the soil.

2.The servo microcomputer controller of the ring shear apparatus controls the torsion device to drive the lower shear box to rotate and apply torsion to the sample,generating shear stress at the shear surface.The shear stress simulates the sliding shear failure of the soil at the sliding surface during slope sliding,and keeps the shear area ofthe sample constant during the test,so that the test process closely matches the actual engineering.

IV.Product Features

1.The unsaturated soil ring shear apparatus performs high-precision ring shear tests,maintaining continuous shear displacement,and can determine shear strength and residual shear parameters,etc.

2.Based on the method of testing residual strength using a ring shear apparatus,this ring shear apparatus can automatically perform the following ring shear test methods:single-stage shear test,pre-shear test,and multi-stage shear test.

3.The ring shear apparatus uses a stepper motor drive to achieve automatic torque control of soil samples;at the same time,the use of an advanced torque sensor avoids the measurement error caused by the force ring and displacement sensor in measuring the sample torque,reduces the installation requirements of the force ring and displacement sensor before the test,and improves the test efficiency.

4.The sample box of the shearing apparatus adopts a detachable structure,which facilitates sample installation and cleaning of the shearing box.The overall hardware structure is robust and durable,the instrument has a long service life,and the test cost is reduced.

5.The axial stress control of the ring shearing machine adopts a air cylinder loading method.The air cylinder loading is combined with the load sensor to realize the servo cyclic loading control of vertical normal stress through servo loading,thereby improving the accuracy of vertical control.

6.Fully automated electronic data acquisition,capable of acquiring and processing test variables such as normal stress,vertical displacement,torque,shear displacement,and shear rate;

7.Integrated amplifier and A/D converter with an integrated microprocessor,capable of processing internally acquired data and controlling the equipment;

8.Fully automated testing control and data acquisition via computer;

9.Instrument control via integrated membrane keys,with real-time display of test data on a high-definition LCD screen;

10.Software automatically stores test data;

IV.Technical Parameters

Sample size:150(O.D.)*100(I.D.)*20mm(H.);average diameter 111.8mm;

Vertical loading 0-5kN,microcomputer-controlled automatic loading;

Dynamic torque:300N.m;

Lower shear box speed 0.001-25°/min(stepless speed regulation),capable of dynamic cyclic shearing,using a dynamic servo motor for loading;

Clay plate air intake value:15 Bar;

Equipped with data acquisition,control,and processing software,it not only collects various parameters during the experiment but also controls the rotation speed of the lower shear box and performs post-processing analysis;

Pore air pressure:0-1.5 MPa,1 kPa;

Pore water pressure:0-100 kPa,accuracy 0.1 kPa,resolution 0.1 kPa;

Features dynamic diffusion bubble scouring and measurement functions(national invention).