JP3359975B2 - Equal volume shear test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equal volume shear test apparatus for measuring and testing the shear strength of soil such as natural ground and compacted embankment while maintaining the same volume at the site and indoors. is there.

[0002]

2. Description of the Related Art Generally, in the case of embankment, it is necessary to carry out a shear strength test in accordance with the depth of the soil at the site and the state of compaction in order to ensure safety against landslides.

Conventionally, a constant-pressure one-sided shear test apparatus has been known as an apparatus capable of performing a soil shear test on site at the site.

[0004] As a shear test apparatus for testing indoors, there is also known an apparatus in which a small pressurizing apparatus is used to perform an equal volume one-sided shear test on a small sample of at most about 10 cm3.

[0005]

In the conventional in-situ shear test apparatus, constant-pressure shearing is performed in a state where the applied load is constant with respect to the soil sample, and the on-site shear test cannot be performed under the same volume condition. Therefore, there is a problem that an accurate test result cannot be obtained due to expansion or contraction of the soil sample at the time of the test.

[0006] Further, the conventional apparatus for testing indoors cannot be used for in-situ measurement, and cannot be tested on soil containing gravel because the sample is small, and the pressure device is small and the soil sample is small. In addition, there is a problem that the reliability of test results is poor because a state change is caused during the order from the site.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a base 1 having an opening 2 through which a soil sample S passes, and a soil sample S projecting upward from the opening 2.
Is formed in a frame shape for storing and holding, and is slidably mounted along a slide guide 4 provided on the base 1, and fixed on the base 1 behind in the sliding direction of the storage and holding frame 3. And a lateral pressing device 6 having the pressing operation rod 7 protruding toward the rear end face of the storage holding frame 3 and a pressing force measurement attached to the distal end of the pressing operating rod 7 and having the pressing rod attached to the distal end in the measurement direction. Vessel 8 and horizontal displacement meter 11 installed on base 1 in front of storage and holding frame 3 in the sliding direction.
And a loading plate 12 placed on the soil sample S stored in the storage holding frame 3, and a vertical pressing force which is installed on the loading plate 12 via a thrust bearing 13, and which vertically pushes the pressing operation rod 15 upward. The device 14, a vertical pressing device 17 attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16 for applying a pressing force vertically downward, and the vertical displacement of the vertical pressing device 14 or the loading plate 12 in the vertical direction. An equal-volume shear test device including a vertical displacement meter 19 for measurement, a stopper 20 provided at a position where the pressing device 14 on the front side in the sliding direction of the holding frame 3 can be locked, and the soil sample S A base 1 provided with an opening 2 through which it passes, and a frame formed to receive and hold a soil sample S projecting upward from the opening 2, and are slidably mounted along a slide guide 4 provided on the base 1. Is A storage and holding frame 3, a lateral pressing device 6 fixed on the base 1 behind the storage and holding frame 3 in a sliding direction, and a pressing operation rod 7 protruding toward a rear end surface of the storage and holding frame 3, 7, a pressing force measuring instrument having a pressing rod mounted at the end in the measuring direction.
A horizontal displacement gauge 11 installed on the base 1 in the sliding direction of the holding frame 3, a loading plate 12 placed on the soil sample S stored in the holding frame 3, and A vertical pressing force device 14 installed through a thrust bearing 13 for vertically pressing the pressing operation rod 15, and a vertically downward pressing force attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16. A vertical pressurizing device 17,
A vertical displacement meter 19 for measuring the vertical displacement of the vertical pressing device 14 or the loading plate 12, a reaction force support member installed at the upper end of the pressurizing device 17, and installed immediately below the storage holding frame 3; The present invention proposes an equal volume shearing test apparatus including a storage holding frame 3 through an opening 2 and a soil sample receiving box 24 constituting a series of soil sample storage spaces.

[0008]

[Function] By adding the functions of vertical displacement measurement and vertical load fine adjustment to the on-site large-scale shear test device, it is possible to directly obtain the in-situ ground equal volume shear strength, and a large soil sample can be used. Therefore, it is possible to perform tests on materials containing gravel, and the reliability of test results is improved.

By mounting a vertical load reaction force support, an earth sample receiving box, and the like on the in-situ device, the in-situ device can be easily converted to a room test.

[0010]

1 to 3 show an embodiment of an equal-volume shearing device for a current position according to the present invention. A base 1 has a rectangular parallelepiped soil projecting upward from an opening 2 provided therein. A storage holding frame 3 formed in a rectangular frame shape for storing the sample S and surrounding the sample S is slidably installed along a slide guide 4 provided on the base 1, and a rear portion of the base 1 in the sliding direction. On the fixed wall 5 fixed above, a lateral pressing device 6 with a constant pushing speed of a screw jack or the like is attached with its pressing operation rod 7 directed toward the rear end surface of the storage holding frame 3 in the sliding direction.

A pressing force measuring device 8 such as a dynamometer for measuring the pressing force is attached to the distal end of the pressing operation rod 7 of the lateral pressing device 6, and further provided on the base 1 at the distal end in the measuring direction. A pressing rod 10 slidably inserted through the supporting guide 9 is attached, and the distal end of the pressing rod 10 abuts on the rear end surface of the storage holding frame 3 in the sliding direction via a cushioning material. Is pushed in the forward direction of the base 1 together with the soil sample S, and the soil sample S is sheared from the original ground.

The base 1 in the front of the storage holding frame 3 in the sliding direction.
A horizontal displacement meter 11 such as a dial gauge for measuring a horizontal displacement due to the pushing movement of the storage holding frame 3 is installed on the upper side.

On the soil sample S stored in the storage holding frame 3, a loading plate 12 formed according to the shape and size of the upper surface thereof is placed at the time of measurement.

A vertical pressing device 1 such as a screw jack is placed on the loading plate 12 via a thrust bearing 13.
4 is placed with the pressing operation rod 15 directed vertically upward, and the tip of the pressing operation rod 15 capable of finely adjusting the reciprocating operation is applied with a pressing force vertically downward through a pressing force measuring device 16 such as a dynamometer. A vertical pressurizing device 17 such as a hydraulic jack is provided.

A support member 18 fixed to the base 1 or the like is provided around the vertical pressing device 14 or the loading plate 12, and the vertical displacement of the vertical pressing device 14 or the loading plate 12 is measured on the supporting member 18. A vertical displacement gauge 19 such as a dial gauge is provided for the purpose.

A stopper 20 is provided on the base 1 for locking the pressing device 14 on the front side of the holding frame 3 in the sliding direction. 14 is supported so as not to move.

At the upper end of the pressurizing device 17, for example, as shown in FIGS. 4 to 6, a reaction force support 21 such as a crawler body of an on-site civil engineering machine is abutted or attached.

Next, FIGS. 7 and 8 show an embodiment of an indoor shear test apparatus. The base 1 having the same structure as the above-mentioned in-situ shear test apparatus is mounted on a base 22. It is horizontally installed in support of the installed legs 23 and the earth sample receiving box 24.

The soil sample receiving box 24 is installed immediately below the storage and holding frame 3 at a stationary position before the movement, and forms a series of storage spaces with the storage and holding frame 3 through the opening 2. The collected soil sample S is stored.

On the base 22, a reaction force support 27 made of a horizontal steel material supported by a support 26 established on a horizontal member 25.
Is attached to the reaction force support 27 and the vertical pressing device 17
Is mounted at the upper end.

The reaction force support 27 supported by the support 26 similar to that described above may be installed on the base 1 of the in-situ shear test apparatus shown in FIGS.

In the above-described configuration, first, in the in-situ shear test, a protective frame for preparing the soil sample S is driven into the ground at the site, and the surrounding ground is excavated to a predetermined area to remove the protective frame, and the ground is integrated with the original ground. Soil sample S rising upward
Create

In this case, the soil sample S is large enough to allow a shear test of general soil containing gravel, for example,
It is preferable that the size is about 30 cm × 30 cm × 15 cm or more in width, and that the size of the storage and holding frame 3 can be adjusted according to the size of the soil sample S. Also set.

Then, the soil sample S is passed through the opening 2 and the storage holding frame 3, and the base 1 is placed on the surrounding ground, a loading plate 12 is placed on the soil sample S, and a thrust bearing 13 is further placed thereon. Vertical pressing device 14, pressing force measuring device 1
6 and a vertical pressurizing device 17 are installed.
7 is engaged with a reaction force support 21 such as a crawler body shown in FIGS.

In this state, the pressurizing device 17 is operated to consolidate the soil sample S at a predetermined pressure, and when the consolidation state is substantially settled (for example, after 30 minutes), the pressurizing state is maintained and the horizontal pressing device is maintained. 6 is extended, and the holding rod 3 is pressed by the pressing rod 10.

At this time, the soil sample S expands and floats or shrinks and sinks under the pressing force. When the soil sample S is left undisturbed, an equal volume cannot be maintained. Alternatively, the vertical displacement of the vertical pressing device 14 is constantly monitored by a plurality of vertical displacement gauges 19 (the average value of the detected values is input to a personal computer for monitoring and recording). 14 is adjusted forward or backward by mechanical adjustment means manually or electrically controlled, and the pressing force of the vertical pressurizing device 17 is increased or reduced to suppress ups and downs and maintain an equal volume.

The pressing force at this time is detected by the pressing force measuring device 16 with time and is inputted and recorded in a personal computer.

The pressing force by the lateral pressing device 6 is always detected by the pressing force measuring device 8 and inputted and recorded on a personal computer.
The movement of the storage and holding frame 3 is monitored and recorded by the horizontal displacement meter 11 (detected values are input to a personal computer and monitored and recorded), and when the movement of the storage and holding frame 3 within a predetermined range is detected, the lateral pressing device 6 is used.
The operation is stopped after detecting the pressing force of.

The required number of soil samples S is prepared in accordance with the purpose of the test, and the test is repeated by the same operation as described above in a state where the load density of the vertical pressing device 17 is changed and the pressure density is different.

Next, in the laboratory test, the apparatus shown in FIGS. 7 and 8 was used.
A sample having a height slightly higher than the original position of about 30 cm × 30 cm × 30 cm in width and height is used, and is loaded into a series of storage spaces of the earth sample receiving box 24 and the storage holding frame 3, and Perform the same operation as in the case of the position shear test to
The soil sample S is sheared between the storage sample and the holding frame 3, and the measurement result at that time is detected and recorded in the same manner as described above.

The conventional constant-pressure shear test can also be performed by the apparatus of the present invention.

As shown in FIG. 9, the correlation between the vertical stress σ of the vertical pressing device 17 via the vertical pressing device 14 and the shear stress τ by the horizontal pressing device 6 as shown in FIG. The relationship between the shear displacement and the shear stress τ of the soil sample S in various states shown in FIG. 12 is known, and based on this, the shear strength of the soil in each part such as embankment and its characteristics can be known.

[0033]

As described above, according to the present invention, the soil sample
Vertical displacement of the loading plate or vertical pressing device due to ups and downs
Always monitor with a vertical displacement meter and check for any tilt
When the direction is detected, the vertical pressing device can be manually or electrically controlled.
Forward and backward adjustment by mechanical adjustment means
Ups and downs of soil samples by increasing or reducing the pressure
It is possible to maintain the equal volume state by suppressing the stress, and it is possible to directly test the shear strength of the soil sample on site while maintaining the equal volume, accurate test results extremely close to the actual natural ground and embankment conditions Can be obtained.

Also, since the storage frame for holding the soil sample can be made large, it can be applied to a wide range of soil from fine-grained soil to gravel soil, and accurate measurement results can be obtained with a large soil sample. .

By attaching a small number of additional members to the in-situ device, an equal volume shear test in a room becomes possible.
Most of the members for both the in-situ and indoor use can be shared, which is economical and rational.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a use state of an in-situ shear test apparatus according to the present invention.

FIG. 2 is a plan view of an in-situ shear test apparatus according to the present invention.

FIG. 3 is a front view of the in-situ shear test apparatus according to the present invention.

FIG. 4 is a longitudinal side view showing a test state of the in-situ shear test apparatus according to the present invention.

FIG. 5 is a longitudinal sectional front view showing a test state of the in-situ shear test device according to the present invention.

FIG. 6 is a plan view showing a test state of the in-situ shear test apparatus according to the present invention.

FIG. 7 is a side view of the indoor shear test device according to the present invention.

FIG. 8 is a front view of the indoor shear test device according to the present invention.

FIG. 9 is a diagram showing one test result according to the present invention.

FIG. 10 is a diagram showing another test result according to the present invention.

FIG. 11 is a diagram showing another test result according to the present invention.

FIG. 12 is a diagram showing another test result according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Opening part 3 Storage holding frame 4 Slide guide 5 Fixed wall 6 Lateral pressing device 7 Pressing operation rod 8 Pressing force measuring device 9 Supporting guide 10 Pressing rod 11 Horizontal displacement meter 12 Loading plate 13 Thrust bearing 14 Vertical pressing device 15 Pressing Actuating rod 16 Pressing force measuring device 17 Vertical pressurizing device 18 Supporting material 19 Vertical displacement meter 20 Stopper 21 Reaction force support 22 Base 23 Support leg 24 Soil sample receiving box 25 Horizontal member 26 Support column 27 Reaction force support S Soil sample

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-150613 (JP, A) JP-A-4-38441 (JP, A) Jpn. Field (Int.Cl. ⁷ , DB name) G01N 3/24 E02D 1/02 G01N 3/00 JICST file (JOIS)

Claims (4)

(57) [Claims] 1. A base 1 provided with an opening 2 through which a soil sample S passes.
And a storage holding frame 3 formed in a frame shape for storing and holding the soil sample S projecting upward from the opening 2 and slidably installed along a slide guide 4 provided on the base 1.
A lateral pressing device 6 fixed on the base 1 behind the storage and holding frame 3 in the sliding direction and projecting the pressing operation rod 7 toward the rear end surface of the storage and holding frame 3; It is attached, a pressing force measuring device 8 having a pressing rod attached to the tip in the measurement direction, a horizontal displacement meter 11 installed on the base 1 in front of the storage holding frame 3 in the sliding direction, and stored in the storage holding frame 3. Loading plate 12 placed on the soil sample S
And a vertical pressing force device 14 that is installed on the loading plate 12 via a thrust bearing 13 and directs the pressing operation rod 15 vertically upward, and is attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16. A vertical pressurizing device 17 that applies a pressing force vertically downward, and a machine that is manually or electrically controlled
An equal volume shearing test apparatus comprising: a vertical pressing device 14 capable of adjusting the forward / backward movement by means of a dynamic adjusting means or a vertical displacement meter 19 for measuring a vertical displacement of the loading plate 12. 2. A base 1 provided with an opening 2 through which a soil sample S passes.
And a storage holding frame 3 formed in a frame shape for storing and holding the soil sample S projecting upward from the opening 2 and slidably installed along a slide guide 4 provided on the base 1.
A lateral pressing device 6 fixed on the base 1 behind the storage and holding frame 3 in the sliding direction and projecting the pressing operation rod 7 toward the rear end surface of the storage and holding frame 3; It is attached, a pressing force measuring device 8 having a pressing rod attached to the tip in the measurement direction, a horizontal displacement meter 11 installed on the base 1 in front of the storage holding frame 3 in the sliding direction, and stored in the storage holding frame 3. Loading plate 12 placed on the soil sample S
And a vertical pressing force device 14 that is installed on the loading plate 12 via a thrust bearing 13 and directs the pressing operation rod 15 vertically upward, and is attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16. A vertical pressurizing device 17 that applies a pressing force vertically downward, and a machine that is manually or electrically controlled
The vertical pressing device 14 or the vertical displacement meter 19 for measuring the vertical displacement of the loading plate 12 which can be advanced and retracted by the dynamic adjustment means, and the portion of the pressing device 14 on the front side in the sliding direction of the holding frame 3 are locked. An equal volume shear test apparatus comprising a stopper 20 provided at a possible position. 3. A base 1 provided with an opening 2 through which a soil sample S passes.
And a storage holding frame 3 formed in a frame shape for storing and holding the soil sample S projecting upward from the opening 2 and slidably installed along a slide guide 4 provided on the base 1.
A lateral pressing device 6 fixed on the base 1 behind the storage and holding frame 3 in the sliding direction and projecting the pressing operation rod 7 toward the rear end surface of the storage and holding frame 3; It is attached, a pressing force measuring device 8 having a pressing rod attached to the tip in the measurement direction, a horizontal displacement meter 11 installed on the base 1 in front of the storage holding frame 3 in the sliding direction, and stored in the storage holding frame 3. Loading plate 12 placed on the soil sample S
And a vertical pressing force device 14 that is installed on the loading plate 12 via a thrust bearing 13 and directs the pressing operation rod 15 vertically upward, and is attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16. A vertical pressurizing device 17 that applies a pressing force vertically downward, and a machine that is manually or electrically controlled
A vertical displacement device 19 for measuring the vertical displacement of the vertical pressing device 14 or the loading plate 12 which can be advanced and retracted by the dynamic adjustment means, and a reaction force support installed at the upper end of the pressing device 17. An equal volume shear test apparatus characterized by the following. 4. A base 1 provided with an opening 2 through which a soil sample S passes.
And a storage holding frame 3 formed in a frame shape for storing and holding the soil sample S projecting upward from the opening 2 and slidably installed along a slide guide 4 provided on the base 1.
A lateral pressing device 6 fixed on the base 1 behind the storage and holding frame 3 in the sliding direction and projecting the pressing operation rod 7 toward the rear end surface of the storage and holding frame 3; It is attached, a pressing force measuring device 8 having a pressing rod attached to the tip in the measurement direction, a horizontal displacement meter 11 installed on the base 1 in front of the storage holding frame 3 in the sliding direction, and stored in the storage holding frame 3. Loading plate 12 placed on the soil sample S
And a vertical pressing force device 14 that is installed on the loading plate 12 via a thrust bearing 13 and directs the pressing operation rod 15 vertically upward, and is attached to the tip of the pressing operation rod 15 via a pressing force measuring device 16. A vertical pressurizing device 17 that applies a pressing force vertically downward, and a machine that is manually or electrically controlled
Vertical displacement device 19 for measuring the vertical displacement of the vertical pressing device 14 or the loading plate 12 which can be advanced and retracted by the dynamic adjusting means, a reaction force support member installed at the upper end of the pressing device 17, and storage and holding An equal-volume shear test apparatus, which is provided immediately below the frame 3 and comprises a storage holding frame 3 through the opening 2 and a soil sample receiving box 24 forming a series of soil sample storage spaces.