JP6000750B2 - Dynamic test equipment - Google Patents

Description

  The present invention relates to a dynamic testing device for rock discontinuities.

  When constructing a structure such as a building, it is necessary to evaluate the stability in consideration of the ground of the construction site, and a structure requiring particularly high stability may be built on the rock. .

  By the way, even if it is a rock mass, for example, when evaluating the stability in a non-uniform location such as a rock mass with an underground cavity or a rock slope, the rock mass is destroyed from a discontinuous surface such as a crack existing in the rock mass The intensity of is measured.

  Therefore, as a shear test device that measures the shear strength of the discontinuous surface of the rock mass, the relative position between the upper shear box and the lower shear box is prevented from shifting, and the load and stress concentration on the shear specimen are reduced. There is known a shear test device for a rock discontinuity surface that can be prevented (see, for example, Patent Document 1).

JP 2008-241247 A

  However, the technique described in Patent Document 1 applies a load in one direction (downward direction) in the vertical direction through the upper shear box to the shear specimen, and in one direction in the horizontal direction through the lower shear box. A static test to apply a shear force is performed.

  In order to evaluate the stability with higher accuracy, the inventor of the present application, in addition to the static test as described above, assumes an actual seismic motion and applies a compressive force applied in the vertical direction or a horizontal direction. It was considered that a more appropriate stability evaluation can be performed by performing a dynamic test in which a shearing force applied to is repeatedly applied.

  Therefore, the present invention is a dynamic test capable of repeatedly applying a compressive force applied in the vertical direction and a shear force applied in the horizontal direction to evaluate the stability of the rock discontinuity. The purpose is to provide a test device.

In order to solve the above problems, the invention described in claim 1 is a dynamic test apparatus for repeatedly applying a compressive force or a shearing force to a specimen having a discontinuous surface, and is above the discontinuous surface. An upper shear box in which a specimen is arranged, vertical load loading means capable of repeatedly loading and unloading a vertical compressive force on the upper shear box, and a vertical controllable vertical load loading means. A load control means, a lower shear box in which a specimen below the discontinuous surface is disposed, a shear force adding means capable of repeatedly applying a shear force to the lower shear box, and the shear force A shear force control means capable of controlling the additional means; a vertical displacement measuring device for detecting a vertical displacement of the upper shear box relative to the lower shear box; and a shear displacement of the lower shear box relative to the upper shear box. Detecting shear displacement meter Comprises a total, and a dynamic repeated vertical stiffness test for adding repeatedly the compressive force to the specimen by the vertical load control means, dynamic for adding repeatedly the shear force to the specimen by the shearing force control means It is possible to select a repetitive single-surface shear test and a dynamic repetitive single-surface shear / vertical rigidity test in which the compressive force and the shear force are repeatedly applied to the specimen by the vertical load control means and the shear force control means. Is a dynamic test apparatus characterized by

  According to this invention, when performing a dynamic test of the specimen, compressive force or shear force is repeatedly applied to the specimen by at least one of the vertical load control means and the shear force control means.

According to a second aspect of the present invention, in the dynamic test apparatus according to the first aspect, the vertical load control means applies a compression force having an arbitrary waveform set by assuming a ground motion by servo control. It is characterized by.

According to a third aspect of the present invention, in the dynamic test apparatus according to the first aspect, the shearing force control means adds a shearing force having an arbitrary waveform set by assuming a ground motion by servo control. It is characterized by.

  According to the first aspect of the present invention, a compressive force or a shear force can be repeatedly applied to the specimen by at least one of the vertical load control means and the shear force control means. It can be performed. That is, since the dynamic test is performed under the conditions assuming actual seismic motion, more appropriate stability evaluation can be performed. In this way, the compressive force applied in the vertical direction and the shear force applied in the horizontal direction in the dynamic test are close to the shaking caused by the actual earthquake, so stability in a state close to the actual phenomenon is achieved. Can be evaluated.

  According to the second aspect of the present invention, the vertical load control means can apply a compression force having an arbitrary waveform by servo control, and can reproduce, for example, a shake during an earthquake. That is, the stability in a state close to an actual phenomenon can be evaluated. That is, it is possible to easily carry out a dynamic test assuming actual seismic motion.

  According to the third aspect of the present invention, the shear force control means can apply a shear force having an arbitrary waveform by servo control, so that, for example, a shake during an earthquake can be reproduced. That is, the stability in a state close to an actual phenomenon can be evaluated. That is, it is possible to easily carry out a dynamic test assuming actual seismic motion.

It is a front view which shows the dynamic test apparatus which concerns on embodiment of this invention. It is a side view which shows the dynamic test apparatus of FIG. It is a top view which shows the dynamic test apparatus of FIG. It is sectional drawing in the AA surface of the dynamic test apparatus of FIG. It is sectional drawing in the BB surface of the dynamic test apparatus of FIG. It is the schematic which shows the apparatus part of the dynamic test apparatus of FIG. It is sectional drawing in CC plane of the dynamic test apparatus of FIG. It is a schematic sectional drawing which shows the apparatus part of the dynamic test apparatus of FIG. It is a schematic block diagram which shows the control part of the dynamic test apparatus of FIG. It is a figure which shows the waveform of the compressive force made to act on a test body by the dynamic test apparatus of FIG. It is a figure which shows the waveform of the shear force made to act on a test body by the dynamic test apparatus of FIG. It is the schematic which shows the measurement of the displacement in a test body by the dynamic test apparatus of FIG.

  The present invention will be described below based on the illustrated embodiments.

  1 to 12 show an embodiment of the present invention. The dynamic test apparatus 1 is used for a dynamic test of a rock discontinuity surface. Here, the dynamic test is to measure a change in strain in a state where a vertical load (compressive force) and a shear force are repeatedly applied to the specimen 2. The magnitude of the compressive force or shear force in the dynamic test is set so that the specimen 2 is not broken, that is, the compressive force or shear force can be repeatedly applied.

  In this embodiment, the load is a compressive force acting substantially perpendicular to the discontinuous surface 21 of the specimen 2 described later, or a shearing force acting substantially horizontally to the discontinuous surface 21. .

  As shown in FIG. 12, the specimen 2 used in this dynamic test is composed of a specimen (upper specimen) 22 above the discontinuous surface 21 and a discontinuous surface 21 with the discontinuous surface 21 as a boundary. A lower specimen (lower specimen) 23 is provided. Here, the discontinuous surface 21 of the specimen 2 is disposed so as to be substantially parallel to the horizontal plane. Specifically, the upper specimen 22 is fixed to the upper shear box 22B by a fixing material 22A such as cement, for example, and is not displaced due to the loading of the compressive force. The displacement (vertical displacement) of the upper specimen 22 is calculated by detecting the vertical displacement of the upper shear box 22B relative to the lower shear box 23B.

  Further, the lower specimen 23 is configured in the same manner as the upper specimen 22, and specifically, is fixed to the lower shear box 23B by a fixing material 23A such as cement, for example. It does not shift. The displacement (shear displacement) of the lower specimen 23 is calculated by detecting the horizontal displacement of the lower shear box 23B relative to the upper shear box 22B.

  As shown in FIG. 2, the upper shear box 22B and the lower shear box 23B are slid in a state in which the specimen 2 is set and can be inserted and removed from the side, and are accommodated in the vertical press frame 6. It can be taken out and taken out.

  As shown in FIG. 1, the dynamic test apparatus 1 mainly includes a vertical hydraulic cylinder 3 as vertical load loading means constituting a vertical load actuator (not shown) and vertical load control means (not shown) for controlling the cylinder. A vertical roller 4, a vertical linear guide 4 G, a vertical load cell 5, a vertical press frame 6, a horizontal hydraulic cylinder 7 as a shearing force adding means constituting a shearing force actuator (not shown), and control thereof. Shearing force control means (not shown), a horizontal roller 8, a horizontal linear guide 8G, a push-pull load cell (shear load cell) 9, and a base 10.

  The vertical hydraulic cylinder 3 can be repeatedly loaded and unloaded with a compressive force in the vertical direction (F1 direction) with respect to the upper shear box 22B. Specifically, as shown in FIG. 6, the vertical hydraulic cylinder 3 applies a compressive force to the upper shear box 22B via a vertical press frame 6 described later. The compression force applied by the vertical hydraulic cylinder 3 is controlled by a control unit 100 as vertical load control means described later, and can be controlled to have a waveform as shown in FIG. 10, for example.

  As shown in FIGS. 1 and 3, the vertical roller 4 is disposed at a position facing both side surfaces of a vertical press frame 6 to be described later, and a plurality of vertical rollers 4 for allowing the vertical press frame 6 to move in the vertical direction. It is composed of bearing rollers. The vertical roller 4 is guided by a vertical linear guide 4G so as to move in the vertical direction. Moreover, the vertical linear guide 4G is comprised with the plate-shaped member in which the rail part extended in an up-down direction was formed, as shown in FIG. 1, FIG. In this way, the vertical press frame 6 can move in the vertical direction by the vertical roller 4 moving up and down along the vertical linear guide 4G in accordance with the change in the compressive force in the vertical direction by the vertical hydraulic cylinder 3. ing.

  The vertical load load cell 5 is for load measurement, and is disposed between the vertical hydraulic cylinder 3 and the vertical press frame 6 as shown in FIGS. 1 and 2, and measures the compressive force in the vertical direction. It is supposed to be. The compressive force measured in the vertical load load cell 5 is transmitted to the load detector 114 of the vertical load control unit 100A of the control unit 100 described later.

  As shown in FIG. 12, the vertical displacement measuring meter (not shown) detects a minute displacement (vertical displacement) of the upper shear box 22B relative to the lower shear box 23B by a sensor (not shown). For example, it is composed of a high-precision contact type digital sensor.

  As shown in FIGS. 1 and 2, the vertical press frame 6 is disposed between the vertical load load cell 5 and the upper shear box 22 </ b> B, and a compression force is loaded on the vertical hydraulic cylinder 3. , It has a function of pressing the specimen 2 downward by its compressive force.

  As shown in FIG. 1, the horizontal hydraulic cylinder 7 can repeatedly push and pull in the shear direction (F2 direction) with respect to the lower shear box 23B. Specifically, as shown in FIGS. 5 to 7, the horizontal hydraulic cylinder 7 can apply a shearing force to the lower shear box 23 </ b> B by pushing and pulling. The shearing force applied by the horizontal hydraulic cylinder 7 is controlled by a control unit 100 serving as a shearing force control means described later, and can be controlled to have a waveform as shown in FIG. 11, for example.

  As shown in FIGS. 1, 2, and 4, the horizontal roller 8 is disposed at a position facing the bottom surface of the lower shear box 23B so that the lower shear box 23B can move in the horizontal direction. It is composed of a plurality of bearing rollers. The horizontal roller 8 is guided to move in the horizontal direction by a horizontal linear guide 8G. Moreover, the horizontal linear guide 8G is comprised by the plate-shaped member in which the rail part extended in a horizontal direction was formed, as shown in FIG.1, FIG.2, FIG.4 and FIG. In this way, as the shearing force is changed by the horizontal hydraulic cylinder 7, the horizontal roller 8 moves left and right along the horizontal linear guide 8G, so that the lower shear box 23B is movable in the left and right directions. Yes.

  The shear load load cell 9 is used for load measurement, and is disposed between the horizontal hydraulic cylinder 7 and the lower shear box 23B as shown in FIGS. It comes to measure. The shear force measured in the shear load load cell 9 is transmitted to the load detector 134 of the shear force control unit 100B of the control unit 100 described later.

  As shown in FIG. 12, the shear displacement meter (not shown) detects a minute displacement (shear displacement) of the lower shear box 23B relative to the upper shear box 22B by a sensor (not shown). For example, it is composed of a high-precision contact type digital sensor.

  As shown in FIG. 1, the dynamic test apparatus 1 having such a configuration is fixed to a base 10, and the base 10 is further fixed to a reaction force frame, a floor surface, or the like by jack bolts 11.

  The dynamic test apparatus 1 has a control unit 100 as a vertical load control unit and a shear force control unit. As shown in FIG. 9, the control unit 100 mainly includes a vertical load control unit 100 </ b> A, a shear force control unit 100 </ b> B, and an arbitrary function generator 101. Thus, it has a function of controlling the position, azimuth, posture, and the like so as to follow the target value.

  The arbitrary function generator 101 is a device that generates a waveform (function) that is a source of compressive force and shear force generated in the vertical hydraulic cylinder 3 and the horizontal hydraulic cylinder 7. Thereby, the compressive force and the shearing force are added in a waveform indicated by a function such as a sine wave or a triangular wave. The waveform is set assuming actual seismic motion. Specifically, for example, waveforms as shown in FIGS. 10 and 11 are set.

  Here, the vertical load control unit 100A is configured as follows.

  The servo valve 111 controls the amount of oil in the vertical hydraulic cylinder 3 based on a control signal from the vertical servo valve setting unit 120, and thereby the position, direction, posture, etc. of the vertical hydraulic cylinder 3 can be controlled. ing.

  The displacement detector 112 detects the displacement of the vertical hydraulic cylinder 3, amplifies the detected displacement by the displacement amplifier 113, and transmits the amplified displacement to the feedback selector 122 of the vertical servo valve setting unit 120.

  The load detector 114 detects a load in the vertical hydraulic cylinder 3, amplifies the detected load by the load amplifier 115, and transmits the amplified load to the feedback selector 122.

  The vibration amplitude setting unit 121 sets an amplitude to be applied to the vertical hydraulic cylinder 3 in order to add a waveform load indicated by a predetermined function in the dynamic test.

  The feedback selector 122 determines whether or not control is required for setting the displacement or load to a set value based on the displacement or load of the vertical hydraulic cylinder 3 detected by the displacement detector 112 or the load detector 114 (deviation from the set value). Presence or absence).

  The excitation center setting unit 123 sets the excitation center.

  The loop gain setting unit 124 sets the gain based on the input values from the excitation amplitude setting unit 121 and the excitation center setting unit 123 and the determination result by the feedback selector 122.

  The servo amplifier 125 amplifies a control signal to the servo so that the vertical hydraulic cylinder 3 has a predetermined displacement and load, and transmits it to the servo valve 111.

  Further, since the shear force control unit 100B is configured in substantially the same manner as the vertical load control unit 100A, description thereof is omitted.

In this way, the control unit 100 controls the vertical hydraulic cylinder 3 and the horizontal hydraulic cylinder 7 so that a predetermined waveform of compressive force or shearing force is applied to the vertical hydraulic cylinder 3 and the horizontal hydraulic cylinder 7. Servo-control the compression force to be applied and the shear force to be applied in the horizontal direction. Here, the combination of the compressive force applied in the vertical direction applied to the specimen 2 and the shear force applied in the horizontal direction by the control unit 100 is set according to the contents of the dynamic test, For example, there are the following combinations.
(A) Dynamic repetitive single-surface shear test This test is for obtaining strength and deformation characteristics in the shear direction of a rock discontinuous surface, and repeats pushing and pulling in the shear direction with a constant compressive force. That is, for example, the pushing and pulling is repeated in the shear direction so as to obtain a waveform as shown in FIG.
(B) Dynamic repetitive vertical stiffness test This test is for obtaining the vertical deformation characteristics of the rock discontinuity (no strength), and repeats loading and unloading of compressive force. That is, for example, the loading and unloading of the compression force are repeated so as to obtain a waveform as shown in FIG.
(C) Dynamic repetitive single-surface shear / vertical stiffness test This test is for obtaining the strength / deformation characteristics in the shear direction and the deformation characteristics in the vertical direction of the rock discontinuity. And unloading are repeated, and pushing and pulling is repeated in the shearing direction with a waveform as shown in FIG.

  Next, the dynamic test method and operation of the specimen 2 by the dynamic test apparatus 1 having such a configuration will be described. Here, in this embodiment, a combination (B) of compression force and shear force will be described.

  First, a compression force waveform for a dynamic test is formulated. For example, a waveform that reproduces the shaking at the time of an actual earthquake is formulated, and a waveform as shown in FIG. 10 is formulated.

  When the formulated waveform is input and set in the control unit 100, the compression force is servo-controlled by the vertical hydraulic cylinder 3 so as to obtain a waveform as shown in FIG. That is, the vertical hydraulic cylinder 3 is controlled to repeat the loading and unloading of the compressive force, and the shear force is not acting. That is, the horizontal hydraulic cylinder 7 is controlled not to operate by the shear force control unit 100B. ing.

  Then, loading and unloading of the compressive force are repeated on the specimen 2. As the vertical hydraulic cylinder 3 changes the vertical compression force, the vertical roller 4 moves up and down along the vertical linear guide 4G, so that the vertical press frame 6 moves up and down. At this time, the displacement and load of the vertical hydraulic cylinder 3 and the displacement of the specimen 2 are measured.

  Then, based on the measured displacement and load of the vertical hydraulic cylinder 3, servo control is performed so that the compression force has a waveform as shown in FIG.

  And a dynamic test is performed until predetermined time passes or the specimen 2 is destroyed.

  After the end of the dynamic test, for example, the stress / strain curve is calculated from the measured displacement and the change is analyzed, whereby the characteristics of the specimen 2 in the dynamic test are analyzed.

  Subsequently, when the dynamic test is performed with the compression force of another waveform, the specimen 2 is replaced, the other waveform is input and set in the control unit 100, and the dynamic test is started.

  In this way, the characteristics of the specimen 2 are analyzed by analyzing the stress / strain curve obtained by the dynamic test with the compressive forces having different waveforms.

  As described above, according to the dynamic test apparatus 1, a compressive force or a shear force is repeatedly applied to the specimen 2 by at least one of the vertical load controller 100A and the shear force controller 100B. Two dynamic tests can be performed. That is, more appropriate stability evaluation can be performed. In addition, since the compression force applied in the vertical direction and the shearing force applied in the horizontal direction in the dynamic test can be made to follow a waveform close to a shake caused by an earthquake by the control unit 100, The stability in a state close to an actual phenomenon can be evaluated.

  Further, since the vertical load control unit 100A applies a compression force having an arbitrary waveform by servo control, for example, it is possible to reproduce a shake during an earthquake. That is, the stability in a state close to an actual phenomenon can be evaluated.

  Furthermore, since the shear force control unit 100B applies a shear force having an arbitrary waveform by servo control, for example, it is possible to easily reproduce a shake during an earthquake. That is, the stability in a state close to an actual phenomenon can be evaluated.

  Although the embodiments of the present invention have been described above, the specific configuration is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. For example, in the above embodiment, the change in strain of the specimen 2 was measured when the compressive force applied in the vertical direction applied to the specimen 2 or the shearing force applied in the horizontal direction was changed. In a fixed state, the dynamic test may be performed by changing the compressive force applied in the vertical direction or the shear force applied in the horizontal direction.

  In addition, the specimen 2 is not limited to the bedrock, but may be other materials such as concrete.

DESCRIPTION OF SYMBOLS 1 Dynamic test apparatus 2 Specimen 21 Discontinuous surface 22 Upper specimen 22B Upper shear box 23 Lower specimen 23B Lower shear box 3 Vertical hydraulic cylinder (vertical load loading means)
4 Vertical roller 4G Vertical linear guide 5 Vertical load cell 6 Vertical press frame 7 Horizontal hydraulic cylinder (shearing force adding means)
8 Horizontal roller 8G Horizontal linear guide 9 Shear load load cell 10 Base 11 Jack bolt 100 Control unit (vertical load control means, shear force control means)

Claims (3)

A dynamic test apparatus that repeatedly applies compressive force and shear force to a specimen having a discontinuous surface,
An upper shear box in which a specimen above the discontinuous surface is disposed;
A vertical load loading means capable of repeatedly loading and unloading a vertical compressive force on the upper shear box;
Vertical load control means capable of controlling the vertical load loading means;
A lower shear box in which a specimen below the discontinuous surface is disposed;
A shearing force adding means capable of repeatedly applying a shearing force to the lower shear box;
Shearing force control means capable of controlling the shearing force adding means;
A vertical displacement meter for detecting a vertical displacement of the upper shear box relative to the lower shear box;
A shear displacement meter for detecting the shear displacement of the lower shear box relative to the upper shear box;
With
A dynamic repeated vertical stiffness test in which the compressive force is repeatedly applied to the specimen by the vertical load control means; a dynamic repeated single-surface shear test in which the shear force is repeatedly applied to the specimen by the shear force control means; A dynamic repeated one-side shear / vertical stiffness test in which the compressive force and the shear force are repeatedly applied to the specimen by the vertical load control means and the shear force control means can be selected .
A dynamic test apparatus characterized by that. 2. The dynamic test apparatus according to claim 1, wherein the vertical load control unit applies a compression force having an arbitrary waveform set by assuming a seismic motion by servo control. The dynamic test apparatus according to claim 1, wherein the shearing force control unit adds a shearing force having an arbitrary waveform set by assuming a ground motion by servo control.

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