JPS6342349Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a resonance method dynamic triaxial testing device.

The resonance method dynamic triaxial testing device applies torsional vibration and vertical axial load to a soil specimen placed in a triaxial compression chamber, and measures characteristics such as soil shear and deformation in the vibration deformation range. It is something to do.
This resonance method dynamic triaxial testing device is equipped with a torsional vibration exciter that applies torsional vibration to the specimen and a vertical loading cylinder that applies vertical load. Transfer load is applied to the specimen.

As shown in FIG. 1, the conventional resonance method dynamic triaxial testing device is designed to have a hoist arm 13 extending horizontally from the upper end of a column 12 that is vertically erected on a base 11. installed. First, the vertical load cylinder 14 is placed vertically on a bracket 15 provided in the middle of the column 12, and is connected to the triaxial compression chamber 17 via a coupling 16.
A loading piston 18 is inserted therein. The triaxial compression chamber 17 is surrounded by triaxial chamber cells 19, and a torsional vibration exciter 20 is disposed in the space above the triaxial compression chamber 17. Torsional vibrations are transmitted to the loading piston 18. Loading piston 1
8 is supported halfway by a bearing 22,
This bearing 22 is held in a bearing housing 23 that is attached and fixed to the triaxial chamber cell 19. code 2
4 is a soil specimen, which is usually cylindrical in shape.
The triaxial compression chamber 17 is mounted on the base 11 via wheels 25 for moving the triaxial compression chamber.

In such a triaxial test device having a conventional structure, vertical axial movement of the loading piston 18 caused by compression of the specimen 24 as well as torsional vibration (repetitive rotation) with respect to the bearing 22 of the loading piston 18, that is, axial direction Slip acts. This axial sliding of the loaded piston 18 acting on the bearing 22 significantly increases the friction coefficient of the bearing 22 compared to when only rotation acts. This increase in the coefficient of friction is particularly noticeable when high-frequency torsional vibration is transmitted to the specimen, such as in a resonance dynamic triaxial testing device, which causes problems such as friction loss of the bearing 22 and shortened bearing life due to wear. will occur. Furthermore, since the torsional vibration exciter 20, the loaded piston 18, the loaded piston bearing 22, its bearing housing 23, etc. are arranged in the triaxial chamber cell 19, the specimen 24 can be moved in and out of the triaxial compression chamber 17. When doing so, as shown in FIG. Pull up (1st
(See the two-dot chain line in Figure 2) will be required. Therefore, the work of placing the specimen 24 becomes troublesome, and the overall size of the apparatus increases. In addition, since the vibrator 20 and the like are provided, the triaxial chamber cell 19 becomes larger.
There is a drawback that the cell tensile internal stress due to lateral pressure increases during the triaxial compression test.

The present invention was developed in view of these points, and aims to reduce the coefficient of friction of the bearing without causing axial slip on the bearing of the loaded piston, thereby increasing the life of the bearing, and adding a triaxial compression chamber. To provide a resonance method dynamic triaxial testing device that can facilitate the work of placing a specimen and downsize the entire device by separating and connecting it to a space in which a vibrator or the like is installed. The purpose is to

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a sectional view showing the structure of the resonance method dynamic triaxial testing apparatus according to the present invention. Reference numeral 11 denotes a base, and a plurality of columns 31 are vertically erected around the base 11, and a box-shaped vibration chamber casing 32 is placed on the upper end of the columns 31.
The lower surface 32a of this vibration chamber casing 32
A cylindrical triaxial chamber cell 33 forming a triaxial compression chamber 51 is detachably attached to the housing by, for example, a bolt 34 . This triaxial chamber cell 33 is
The inner periphery of its lower end fits into the outer periphery of a flange-shaped cell lower plate 36 at the upper end of a spacer pole 35 placed perpendicularly on the center of the base 11, and this fitting portion is sealed by an O-ring 37. Further, below the spacer pole 35, a support plate 38 for the flange-shaped triaxial chamber cell 33 is attached. A vertical load cylinder 1 is installed at the upper end of the vibration chamber casing 32.
4 is placed with its piston 14a facing vertically downward, and the piston 14a is inserted into a vibration chamber 39 formed by a vibration chamber casing 32. The lower end of this piston 14a is connected to the vibration chamber 3
It is connected to the upper end of a loading piston 40 disposed inside the piston 9 via a thrust bearing 41 . A horizontal bar 42 is provided at the upper end of the loading piston 40.
is fixed to the horizontal bar 42, and a torsional vibration exciter 20 is connected to this horizontal bar 42. In addition, a radial ball bearing 43 is located in the middle of the loading piston 40.
The ball bearing 43 is rotatably supported by a bearing housing 44 disposed within the vibration chamber 39 . This bearing housing 44 has a cylindrical portion 4 that partially extends in the lateral direction.
5, a through hole is bored in this cylindrical portion 45 parallel to the axis of the loading piston 40,
A slide ball bearing 46 is installed in this through hole. This slide ball bearing 4
6 is fixed perpendicularly to the vibration chamber casing 32 and is fitted to a guide bar 47 disposed within the vibration chamber 39 so as to be slidable in the axial direction. A sample cap 48 is attached to the lower end of the loading piston 40, and the soil sample 24 is disposed between the sample cap 48 and a pedestal 49 placed at the center of the upper end of the spacer pole 35. Reference numeral 50 denotes a three-shaft compression chamber moving wheel, which is fixed to the lower surface of the three-shaft chamber cell support plate 38.

The operation of the resonance method dynamic triaxial testing apparatus according to the present invention having such a configuration will be explained. First, when placing the soil specimen 24 in the triaxial compression chamber 51, by removing the bolts 34, the triaxial chamber cell 33 is separated from the vibration chamber casing 32, and the triaxial chamber cell support plate is removed. 38 and place it thereon (see the two-dot chain line in Fig. 2). After this work,
By moving the spacer pole 35 in the horizontal direction using the wheels 50, the specimen 24 can be easily taken out and a new specimen can be placed thereon. Next, after placing the specimen 24 in the triaxial compression chamber 51, the vertical load cylinder 14 and the vibrator 20 are operated to apply a vertical axial load and torsional vibration to the specimen 24. In this case, the loading piston 40 rotates repeatedly and the specimen 2
4 compression causes it to move vertically downward. This vertical downward movement of the loading piston 40 is transmitted to the bearing housing 44 via the radial ball bearing 43, and as the cylindrical portion 45 of the bearing housing 44 moves vertically downward along the guide bar 47, the bearing housing 44 itself moves vertically downward. Therefore, only the repeated rotation of the loaded piston 40 acts on the radial ball bearing 43, and no axial sliding acts on it at all.

In this way, the resonance method dynamic triaxial testing apparatus according to the present invention has a triaxial compression chamber in which the specimen is placed, an exciter,
Since the vibration chambers in which the loaded piston bearing housing and the like are arranged are formed independently and separably connected, the work of mounting the specimen is much easier than in conventional devices. In addition, the shape and dimensions of the triaxial chamber cell can be made to match the size of the specimen, regardless of the size of the vibrator, etc., so the diameter and height of the triaxial chamber cell can be reduced. This makes it possible to reduce the size and weight of the cell, and to reduce the cell tensile internal stress caused by lateral pressure.
Thereby, the cell for the triaxial chamber can be made of transparent acrylic resin, and the state of the soil specimen during the test can be clearly observed from all sides. In addition, only repeated rotation acts on the bearing of the loaded piston, and axial sliding due to vertical downward movement of the loaded piston does not act, so the friction coefficient of the bearing is small, resulting in problems such as increased friction loss and shortened bearing life. do not have. Further, since the vertical movement of the loading piston is guided by the cylindrical portion of the bearing housing, the bearing spacing of the loading piston can be reduced, and the length of the loading piston can be shortened. This makes it possible to reduce the torsion angle that occurs at the lower end of the loading piston, making it possible to accurately and stably transmit torsional vibration at high frequency to the specimen.

In the embodiment of the present invention, a radial ball bearing is used as the loaded piston bearing, but a metal type sliding bearing may also be used. Further, as a method for arranging the bearing housing, for example, a hydraulic cylinder mechanism can be used in addition to the method shown in the embodiments.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a conventional resonance method dynamic triaxial testing apparatus, and FIG. 2 is a sectional view showing the structure of a resonance method dynamic triaxial testing apparatus according to the present invention. 14... Vertical load cylinder, 20... Torsional vibration exciter, 24... Soil specimen, 39... Vibration chamber, 40... Loading piston, 43... Bearing, 4
4...Bearing housing, 45...Cylindrical portion, 47...
...Guide bar, 51...Triaxial compression chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Equipped with an exciter for applying torsional vibration and a cylinder for applying vertical load, torsional vibration and vertical axial load are applied to a soil specimen placed in a triaxial compression chamber. In the resonance method dynamic triaxial testing apparatus for testing soil quality, the vibrator and the cylinder are installed in a vibration chamber formed above the triaxial compression chamber, and the triaxial compression chamber 1. A resonance method dynamic triaxial testing device, characterized in that it is separably installed below a vibration chamber and has a diameter smaller than that of the vibration chamber. 2 The triaxial compression chamber is formed by a cylindrical triaxial chamber cell, and the upper end of the triaxial chamber cell is separably attached to the vibration chamber, and the inner periphery of the lower end is attached to the triaxial test equipment base. Resonance method dynamic triaxial test according to claim 1 of the utility model registration, characterized in that the upper end of the spacer pole is fitted to the outer periphery of the flange-shaped cell lower plate vertically placed in the center of the spacer pole. Device. 3. A utility model registration request characterized in that a flange-shaped support plate for a three-axis chamber cell is attached to the lower part of the spacer pole, and a three-axis compression chamber moving wheel is fixed to the lower surface of this support plate. Resonance method dynamic triaxial testing device according to scope 2.