The invention discloses a direct shear test system for anisotropy of geosynthetics and an implementation method of the direct shear test system The direct shear test system comprises a test bed rack, a slewing bearing, a dial, a lower shearing box, an upper shearing box, a vertical loading device, a horizontal loading device, a guide rail, a displacement sensor, a slewing bearing control device and a bearing plate, wherein the guide rail and the displacement sensor are arranged on the test bed rack; the dial and the slewing bearing control device are respectively arranged on the slewing bearing; the vertical loading device is arranged on the slewing bearing sequentially through the bearing plate, the upper shearing box and the lower shearing box; the lower shearing box is driven to rotate by the slewing bearing; the cross section of a geosynthetic which needs to be subjected to a shear test is round, and the diameter of the geosynthetic is same as the outer diameter of the lower shearing box; the horizontal loading device is connected with the slewing bearing and can slide on the guide rail According to the direct shear test system for the anisotropy of the geosynthetics, the technical problem that the engineering practice cannot be truly reflected by the interface mechanical characteristics of the geosynthetics and fillings which are obtained in the test in the prior art is solved

Direct shear test system for anisotropy of geosynthetics and implementation method of direct shear test system

The invention relates to a direct shear and draw test instrument for anisotropy of geotechnical materials and implementation method thereof. The test instrument comprises a test rack, a horizontal loading system, a rotary drive system, a test box, a vertical loading system, a measuring system, a clamp and a lifting system. Compared to the existing technology, in the invention, the two lower test boxes are of different dimensions; the direct shear test for the equal shear surface of geotechnical synthetic material can be implemented, the direct shear test of the variable shear surface of the geotechnical material can also be implemented. The lift system can adjust the position of the horizontal loading device, so that the direct shear test and draw test of the geotechnical materials can be implemented under the same test conditions. The rotary drive system can perform the direct shear and draw test for the geotechnical synthetic material and geotechnical sample at any angles, and tests the anisotropy of geotechnical synthetic material. The upper test sample box is fixed on a fixed board of the upper test sample box; the height between the upper test sample box and the lower test sample box can be adjusted, and friction resistance between the upper and the lower shear surface is reduced.

Direct shear and draw test instrument for anisotropy of geotechnical materials and implementation method thereof

The invention discloses a multifunctional cylindrical test piece shearing test clamp. The clamp is characterized in that the clamp comprises a fixing device (1), a pretension bolt (2), a loading device (3), a scale shearing inner ring (4), a movable shearing inner ring (5) and a middle shearing inner ring (6); and cantilevers at two sides of the fixing device (1) are respectively provided with a scale shearing inner ring fixing hole (8) and a movable shearing inner ring fixing hole (9). The clamp is suitable for cylindrical test pieces, and can directly carry out shearing test on existing bolts, pins and other cylindrical parts, and a processing technology of non-existing test pieces during the test of the non-existing test pieces; the telescoping of the movable shearing inner ring can be adjusted through the pretension bolt to realize the test of different shearing belt widths of the cylindrical test pieces; and an included angle between the material direction and the loading direction of the cylindrical test pieces is adjusted to realize the measurement of the shearing mechanical performances of an anisotropic material in different directions.

Multifunctional cylindrical test piece shearing test clamp

The invention discloses a direct shear apparatus fixing device for studying the anisotropy of a structural surface sample. The upper portion of a magnetic steering unit is fixedly connected with a flat plate, a force transfer mechanism is placed on the flat plate, the flat plate and the force transfer mechanism are fixed together through strong magnetic force generated by the magnetic steering unit, a first scale line is arranged on the flat plate, and a second scale line is arranged at the position, matched with the first scale line, of the force transfer mechanism. A wrapping mechanism is placed in the force transfer mechanism and fixedly connected with the force transfer mechanism together, the structural surface sample is wrapped in the wrapping mechanism, after direct shear apparatus carries out direct shear of one direction on the structural surface sample, fixed magnetic force is lost between the flat plate and the force transfer mechanism by switching off the magnetic steering unit, the force transfer mechanism is rotated to a next scale line of the first scale line, the magnetic steering unit is switched on again, direct shear of a next direction on the structural surface sample can be achieved, and direct shear of all the directions on the structural surface sample is achieved. The anisotropy of the structural surface sample can be conveniently studied.

Direct shear apparatus fixing device and method for studying anisotropy of structural surface sample

The invention discloses a device and method for measuring the mechanical property of a roadbed filler and a geotechnical reinforcement interface. The device comprises a horizontally arranged bottom plate; a shear rotary disc is arranged on the bottom plate; the shear rotary disc comprises an inner cylindrical filling cavity; an outer circular filling cavity is arranged outside the inner filling cavity; the bottom centre of the inner filling cavity is connected with the output end of a rotation driving device through a rotating shaft; a circular geotechnical reinforcement is arranged on the relative rotary surface of the inner filling cavity and the outer filling cavity; the inner filling cavity and the bottom plate are in free rolling connection; a cylindrical aeration pressure device is arranged in the centre of the inner filling cavity; a compression device is arranged both over cover plates of the inner filling cavity and the outer filling cavity; and the cover plates of the inner filling cavity and the outer filling cavity are respectively in free rolling connection with the corresponding compression devices. According to the device and the method in the invention, the contactarea of the roadbed filler and the geotechnical reinforcement interface is always not changed in a shearing process; furthermore, the interface normal stress is steady; and an interface mechanical property index measurement result is accurate and reliable.

Device and method for measuring mechanical property of roadbed filler and geotechnical reinforcement interface

The utility model discloses a geosynthetic material anisotropic direct shear test system, this system include test bench, slewing bearing, calibrated scale, lower shear box, go up shear box, vertical loading device, horizontal loading device, guide rail, displacement sensor, slewing bearing controlling means and loading board, last guide rail and the displacement sensor of being provided with of test bench, last calibrated scale and the slewing bearing controlling means of being provided with respectively of slewing bearing, vertical loading device loops through loading board, last shear box and lower shear box and sets up on slewing bearing, slewing bearing drives shear box rotation down, geosynthetic material transversal of waiting to carry on shear test is personally submitted circularly, and its diameter is the same with shear box's down external diameter, horizontal loading device and slewing bearing link to each other and can be in the enterprising line slips of guide rail. The utility model provides an among the prior art the experimental geosynthetic material who obtains can't truly reflect the technical problem that the engineering is actual with the interface mechanical properties who bankets.

Xue Chunming

Papers

Direct shear test system for anisotropy of geosynthetics and implementation method of direct shear test system

Geosynthetic material anisotropic direct shear test system