JPH09166534A - Simplified original position rock shearing testing machine and testing method usin the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily execute an original position shearing test for rock-bed by installing a testing machine base at a rock-bed to be tested with anchor bolts prior to the preparation of a specimen. SOLUTION: A specimen preparing device is installed in a prescribed position of a testing machine base 1 previously fitted to a rock-bed with anchor belts. A loading device installation hole 4 for installing a loading device 2 is drilled changing the fitting position of the specimen preparing device to the testing machine base 1. The loading device 2 is integrated in such a way that two small hydraulic cylinders 10, 11 can be loaded in the vertical and horizontal directions by +15 deg.. After completing the preparation of a specimen 3 and the loading device installation hole 4, the specimen preparing device is removed from the testing machine base 1, the loading device 2 is installed at the testing machine base 1 with bolts, and a displacement gage 13 is installed at the specimen 3 to execute a shearing test. In this way, a faultless shearing testing small specimen 3 can be easily prepared, and the loading device 2 can be easily installed in a prescribed position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tester which can easily carry out preparation of a specimen for shear test in situ rock and measurement of its shear strength, and a test method therefor.

[0002]

2. Description of the Related Art A conventional in-situ shear strength test of a rock mass has a large test surface for the purpose of considering cracks contained in the rock mass (there are many squares with a side of 60 cm). there were. -It is impossible to test the local rock strength, which has a narrow distribution range required for mechanical analysis of underground caverns.・ Because it takes time and cost (about 10 million yen per month for 4 specimens (the number of specimens is limited, and it is often difficult to judge the shear force and internal friction angle due to variations among specimens).・ Because it is necessary to place concrete, it is difficult to carry out tests on the wall and top.

[0003]

In order to eliminate these drawbacks, it is required to make the specimen itself small. However, in the conventional specimen preparation method using a guaiamond cutter or the like, a small specimen can be created at the time of preparation. Deterioration in strength, even if a small specimen could be intact, there was no dedicated equipment for loading the small specimen, and the test time and cost were not much different from the large shear test.

[0004]

[Means for Solving the Problems] To solve these problems, the following means were used. -The testing machine shall consist of the specimen preparation device, loading device, and testing machine base. The tester base is for easy installation of the loading device at the position of the specimen to be created, and is installed with anchor bolts on the rock to be tested before making the specimen. After that, the sample preparation and test device installation holes are drilled by mounting the sample preparation device at a predetermined position on this base, and after this work, the loading device is mounted on the same tester base to perform the shear test.・ In order to make a small test piece intact, the test piece is shaped like a cylinder with roots, and a test tube creation device (core cutter) is used to drill holes concentrically with core tubes of different diameters, and then remove with a chisel. To do. At this time, the specimen preparation device is installed with bolts at a predetermined position on the tester base previously attached to the bedrock. -Adjacent to this rooted cylindrical test piece, a hole for installing a loading device (loading device installation hole) is drilled by changing the mounting position of the test piece creation device on the tester base. -The loading device has two small hydraulic cylinders integrated so that they can be loaded vertically and horizontally +15 degrees.・ After completing the creation of the specimen and loading device installation holes, remove the specimen preparation device from the tester base, install the loading device on the tester base with bolts, and install the displacement meter on the tester. Perform a shear test.

[0005]

By doing so, it is possible to easily create a small test piece for a shear test that is not damaged and to easily install the loading device at a predetermined position. Therefore, it is possible to perform a shear test in a short time and at a low cost. And it is possible to test in narrow range or side wall / top test which was not possible until now.

[0006]

[Example] Testing machine base

FIG.

FIG. 2

[Fig. 3] After fixing to the rock with anchor bolts

[Fig. 2] Attached concentric boring, leaving a cylindrical shape inside, and cutting with a chisel, a cylindrical specimen with roots

FIG.

FIG. 2

FIG. 3 is created. In addition, the loading position of the loading device is drilled by changing the fixed position of the sample preparation device.

FIG.

FIG. Loading cup for specimen

[Fig. 3] is installed by filling quick-setting cement in between, and a rod bearing, a pressure receiving plate, and a pressure ball seat are installed on the upper part thereof. Install a reaction plate on the side opposite to the specimen of the loading device installation hole (above)

FIG. 3). The loading device that actually performs the test is a device in which the vertical loading hydraulic cylinder and the shear force loading hydraulic cylinder are attached to the loading device plate at predetermined positions and angles.

FIG.

[Fig. 3] After the above work, bolts are attached to the tester base. After this, install a displacement gauge to measure the horizontal and vertical displacement of the specimen.

[Fig. 3]: Stress is applied to the test piece in the order of vertical and horizontal, and the changes in stress and displacement at this time are measured and recorded in a microcomputer system.

FIG.

[0007]

The following effects are brought about by this test machine and test method.・ It became possible to test thin layers of mudstone between sandstones, such as narrow layers.・ Since the test can be performed quickly and economically (4 test piece test execution period: 2 days, about 1 million yen), the number of test pieces can be easily increased, and more clear test results can be obtained.・ Tests that were previously possible only on horizontal floors can now be easily performed on slopes and walls.

[Brief description of the drawings]

FIG. 1 is a schematic view (perspective view) of the present invention.

[Explanation of symbols]

1 is a tester base, 2 is a loading device, 3 is a rooted cylindrical specimen, 4 is a loading device installation hole

FIG. 2 is a device for producing a specimen (perspective view) of the present invention.

[Explanation of symbols]

1 is a tester base, 3 is a rooted cylindrical specimen, 5 is a specimen preparation device

FIG. 3 is a detailed view (cross-sectional view) of the loading section of the present invention.

[Explanation of symbols]

1 is a testing machine base, 2 is a loading device, 3 is a rooted cylindrical specimen, 4 is a loading device installation hole, 6 is a rod bearing, 7 is a pressure receiving plate, 8 is a pressure ball seat, 9 is a reaction force plate, Reference numeral 10 is a vertical loading hydraulic cylinder, 11 is a shearing force loading hydraulic cylinder, 12 is a loading device plate, and 13 is a displacement gauge.

FIG. 4 is a measurement system diagram of the present invention.

Claims (2)

[Claims] 1. A simplified in-situ rock shear tester capable of easily producing a small in-situ rock shear test specimen and performing an in-situ shear test therefor. 2. An in-situ shear test method for performing in-situ rock mass specimen preparation and a shear test using the tester according to claim 1.