JP3368535B2 - Simple compaction tester and compaction test method by compaction using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compaction tester which enables a compaction test by compaction with a small amount of sample and which is smaller in size than conventional machines. is there. Further, the present invention relates to a compaction compaction test method by means of compaction in which substantially the same data as the results of the compaction compaction test by conventional compaction can be obtained using this testing machine.

[0002]

2. Description of the Related Art At present, as a compaction test method by tamping in Japan, Procto
JIS A 1210 and JSF T 711-1990, which are based on the compaction method by impact load proposed by r, are mainly applied. The test method stipulated in JIS A 1210 and JSF T 711-1990 makes it possible to know the relationship between the dry density and the water content ratio when the soil is compacted, which makes it optimal for compacting the soil in the most stable state. The water content can be predicted.

In a conventional tester used for the compaction test by the tamping, a rammer supporting rubber B is attached to the inner peripheral surface of the rammer shaft A as shown in FIG. It is sandwiched by a pulley D having a notch C formed as a rammer open surface, the pulley D is rotated in a certain direction to move the rammer E up and down, and a sample in a mold G having a spacer disk F fixed to the lower part is projected. It has a structure that hardens.

[0004]

By the way, in order to obtain the optimum water content, the construction machine used at the site (difference in compaction work) and the depth at which earth and sand are used are shown in FIG. It is necessary to carry out the test by changing the compacting work as shown. Above JIS A 1210 and JSF T 711-1990
According to the standard specified in, the diameter is 10 cm and the height is 12.73 c.
m and a diameter of 15 cm and a height of 12.5 cm are said to be used, and the volume of each mold is 100
It is 0 cm3 and 2209 cm3.

Therefore, the required amount of the sample is about 2.7 kg and 6.0 kg per mold. Therefore, it is necessary to use a huge amount of sample in order to confirm the influence of the optimum water content ratio and the dry density. is there. Actually, the amount of sample required for carrying out the test shown in FIG. 2 is about 300 kg, and therefore there are many difficulties in considering the sample collection and sample adjustment. The conventional test method is 1000 cm3 and 2209c.
Since it is to observe how many samples can be compacted by compaction in the m3 mold volume, there are many necessary processes such as the need for end face molding. Considering the adjustment of, it is a difficult task.

On the other hand, the conventional tester requires a pulley having the same circumference as the drop height as shown in FIG. 1 and has a problem that the machine becomes large because the rammer shaft must be lengthened. It was Further, since the lift amount of the rammer shaft is determined by the size of the pulley, the drop height cannot be easily changed. Also,
When compacting, the pressure in the side wall direction increases by performing the compaction from above, and the compaction work to the lower layer of the specimen is insufficient, so the rammer weight should be sufficiently heavy to compact to a uniform density. However, it is necessary to increase the number of times of compaction and the number of layers.

That is, if the mold can be miniaturized to reduce the required amount of the sample at one time, it becomes easy to collect the sample and adjust the sample. If the tester can be made smaller and lighter by making the mold smaller, shortening the rammer axis, and reducing the weight of the rammer, the tester can be easily transported to the test site and installed, and the optimum water content ratio can be easily confirmed. You can do a test for. Further, if it is possible to compact to a uniform density with a small number of compaction times, the labor required for the test can be greatly saved, and highly accurate test results can be performed by a simple test.

On the other hand, if the data obtained simply by such a tester has a correlation with the data obtained by the conventional test method such as JIS, the reliability of the obtained data can be confirmed and the data can be confirmed. Therefore, the present tester can be used in place of the conventional tester and can be widely put into practical use.

Further, it would be convenient if a test piece manufactured by using a testing machine could be applied to a strength test such as a uniaxial compression test. For that purpose, it is appropriate that the height is about 1.8 to 2.5 times the diameter, but for that purpose, it is necessary to manufacture a test piece having a density as uniform as possible.

[0010]

Therefore, in the simple compaction tester according to the present invention, a bottom plate provided with a cylindrical fixed piston is provided in a lower portion of a frame of the tester, and a fixed piston acts in a vertical direction. The cylindrical mold which is slidable with respect to the fixed piston is inserted into the cylindrical mold by covering the fixed piston from the lower side of the cylindrical mold. Is arranged so that it can move vertically in a vertical direction while sliding with respect to the fixed piston, and a movable piston that is slidable with respect to the cylindrical mold and has a piston rod of a desired length on the back is Insert the piston so that the moving piston is on the bottom and the piston rod is on the top, and the moving piston and the piston rod move vertically while sliding on the cylindrical mold. Downward movement is disposed so as to be, also the weight of the piston rod insertion hole in the axial substantially cylindrical shaped is formed,
The piston rod is inserted into the piston rod insertion port of the weight so that the weight slides on the piston rod and collides with the back surface of the moving piston.

Further, it is provided with an automatic weight lifting and dropping mechanism for automatically lifting the weight that is falling in contact with the back surface of the moving piston and automatically dropping it from a desired height. is there.

The compaction test method by tamping according to the present invention uses the simple compaction tester of the present invention, the sample is 350 g, the inner diameter of the cylindrical mold is 5 cm,
The weight of the weight is 3.5 kg, and the drop height of the weight is 40 cm.
The weight is dropped 13 to 15 times.

[0013]

[Function] When the cylindrical mold is sandwiched between the fixed piston and the moving piston from above and below, and the weight is dropped on the back surface of the moving piston to cause a collision, the sample in the mold is compacted from above by the moving piston and fixed. The piston also crushes it from below. Since the specimen in the mold is above, it is compacted at the same time to produce a specimen with a uniform density in the vertical direction.

Further, the rammer and the rammer shaft which are integrally formed as the projecting rod are separated into a moving piston and a weight,
By making it possible to easily change the drop height of the weight and the weight of the weight, it is possible to perform an appropriate test according to the sample and reduce the size of the machine.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the simple compaction tester of the present invention will be described with reference to FIG. Reference numeral 1 denotes a bottom plate provided in a lower portion of a frame 2 of the tester. A fixed piston 3 having a cylindrical shape (height 3 cm, diameter 5 cm in the illustrated example) is perpendicular to the bottom plate 1. It is provided so as to be oriented.

Reference numeral 4 denotes a cylindrical mold which is slidable with respect to the fixed piston 3 (in the illustrated example, the length is 20 cm, the inner diameter is 5 c).
m), and the fixed piston 3 is inserted into the cylindrical mold 4 so as to cover the fixed piston 3 from the lower side of the cylindrical mold 4. The cylindrical mold 4 is arranged so as to be vertically movable while sliding on the fixed piston 3. In addition, 5 is a guide rod arranged vertically to the left and right of the bottom plate, 6 is a guide member provided in the cylindrical mold 4 so that the through hole slides with respect to the guide rod 5,
It assists the vertical movement of the cylindrical mold 4 in the vertical direction.

Reference numeral 7 denotes a moving piston (diameter 5 cm in the illustrated example) slidable with respect to the cylindrical mold 4 and having a piston rod 8 of a desired length on the back surface. The piston rod 8 is at the bottom and the piston rod 8 at the top. Reference numeral 9 is a guide guide provided on the upper part of the frame 1 of the tester, in which a piston rod 8 is slidably inserted into a through hole formed in the center, and the moving piston 7 slides on the cylindrical mold 4. On the other hand, the moving piston 7 and the piston rod 8 can move vertically in the vertical direction.

Reference numeral 10 is a weight having a substantially cylindrical shape and a piston rod insertion port 11 formed in the axis thereof. The weight 10 slides on the piston rod 8 and collides against the back surface of the moving piston 7.
The piston rod 8 is inserted into the piston rod insertion port 11 of the weight 10. Reference numeral 12 is a brim-shaped locking portion provided on the weight 10. Then, the weight 10 is automatically pulled up from the state of being in contact with the back surface of the moving piston 7, and the piston rod 8 is slid by an automatic weight lifting and dropping mechanism which is automatically dropped from a desired height. It is designed to move up and down. The weight 10 can be pulled out or removed from the piston rod 8 so that the weight weight can be changed.

The automatic weight lifting and dropping mechanism has, for example, the following configuration, but the automatic weight lifting and dropping mechanism may be of any type as long as it operates as described above. An example is shown in.

Rotating shafts 14 having chain driving sprockets 13 provided on the left and right sides of the piston rod 8 at the upper and lower positions of the testing machine frame 2 are respectively provided on the rear side (rear side) of the piston rod 8. Arrange. The chain 15 is placed between the upper and lower sprockets 13 on the left and right sides, respectively.
The rotating shaft 14 is driven by a motor (not shown) so that the chain 15 on the front side rotates from bottom to top.

A supporting portion 16 for supporting a weight is provided at an arbitrary position facing each other on the left and right chains 15, and the engaging portion 12 formed on the weight 10 is detachably engaged with the supporting portion 16. A stop pin 17 is provided, the locking pin 17 is movable in the horizontal direction, and the locking pin 17 normally protrudes from the support portion 16 toward the weight 10 to lock the locking portion 12 of the weight 10. It is urged by a spring 18 so that

On the other hand, support bars 19 for mounting the open claws, which can be fixed to the piston rod 8 at arbitrary positions, are provided, and the left and right ends of the support bar 19 are formed with tapered surfaces facing downward from the outside. An opening claw 20 that is tapered downward is attached.

Then, the chain 15 rotates and the supporting portion 1
6 rises from below, and the locking pin 17 locks the locking portion 1 of the weight 10.
When engaged with 2, the weight 10 is also pulled up by the locking pin 15 as shown in FIG. Further, when the locking pin 17 rising from the bottom comes into contact with the opening claw 20 of the support bar 19 fixed at the desired position of the piston rod 8, the locking pin 17 is supported along the tapered surface of the opening claw 20 by the supporting portion 16. Pushed to the side, locking pin 1
When 7 is pushed in by the release claw 20 until it is disengaged from the engaging portion 12 of the weight 10, the weight 10 automatically falls, and as shown in FIG. collide.

[0024]

EXAMPLES Next, a compaction test method by tamping using the simple compaction tester of the present invention will be described. Conventional JI
SA 1210 and JSF T 711-1990, 2209 cm3 for 15 cm mold, 100 for 10 cm mold
The wet density and dry density of the specimen are calculated by compacting the soil in a limited volume of 0 cm3 and measuring the weight. In this method, a sample whose weight (dry weight) was measured beforehand was used as a mold. The volume is measured after pouring and compacting for any number of times, and the wet density and dry density of the sample are calculated.

The test procedure is as follows. 1) Adjust the water content of the sample to an arbitrarily set value. Soil that takes a long time to become compatible with water, such as soil that contains a large amount of clay, is placed in an airtight container so that the water content ratio does not change, and allowed to stand for 12 hours or more before use in the test. 2) Put the sample in a mold, and compact it with the weight drop height (rammer height) and the weight drop times (ramming times) set arbitrarily. 3) After compaction, measure the sample height with a digital displacement meter to calculate the sample volume and wet / dry density. 4) Repeating the above operation with 6 to 8 kinds of water content centering on the expected optimum water content.

In order to evaluate the test results, JIS A 1210 can be used for comparison with conventional test data.
And based on JSF T 711-1990. Since the compaction work can be calculated by the following formula in the conventional test method, the following formula was also applied in this test to determine the test conditions.

Ec = WR.H.NB.NL / V (cm
* Kgf / cm3) where: WR: weight weight (kgf), H: weight drop height (cm), NB: number of compactions per layer, NL: number of layers, V: mold volume . In the following description and drawings, the weight weight may be referred to as the rammer weight, the weight drop height may be referred to as the rammer drop height, and the weight drop frequency may be referred to as the compaction frequency.

The amount of the sample charged was 200 g in advance and 3
Although it was carried out at 00 g, it was decided to carry out at 350 g because the wet density and the dry density are extremely increased and the changes in the wet density and the dry density with respect to the water content are sensitive. Also,
Since this test method is premised on being a simple test method, the number of compaction layers was set to one, the weight weight was changed, and the number of compaction times and the weight drop height were changed.
The mold used in this test had a diameter of 5 cm and a height of 2
A 0 cm one was used.

[Test 1] First, in order to confirm the effect of consolidating the specimen in the mold, which is the feature of the testing machine of the present invention, by the upper moving piston and also by the lower fixed piston, the fixed piston is confirmed. A comparative test was carried out with and without. When operating the fixed piston, the height between the mold and the bottom plate is 2 cm.
The spacer disk 21 is sandwiched so that it becomes (see FIG. 4), and the first compaction is performed to prevent the mold from dropping spontaneously. After this spacer disk is removed, the fixed piston also compacts in the subsequent compaction. I tried to do it. On the other hand, when the fixed piston was not operated, the spacer disk was not used, and the mold was directly contacted with the bottom plate, that is, the fixed piston was not operated and the compaction was performed.

As a sample, 350 g of masa soil adjusted to have a uniform water content was separated and added with 10% of cement. 1 layer x 30 times, 1 layer x 60 times, 1 layer x 9 with and without a disc
A specimen is prepared by performing tamping at 0 times, 3 layers × 20 times, and the specimen is aged in water until it can be cut with a diamond cutter. Then, after cutting, the sample was dried in a drying oven until it became an absolutely dry state, and the sample volume and dry density of the upper layer, the intermediate layer and the lower layer were calculated. The results are shown in Table 1. The table shows the test conditions and the dry density of the test piece.

[0031]

[Table 1]

From the above results, it can be confirmed that the dry densities of the intermediate layer and the lower layer are reduced as compared with the upper layer when there is no disc. However, when there is a disc, compared with the dry density of the upper layer, that of the intermediate layer can be confirmed to be slightly reduced, but in the lower layer it exceeds that of the intermediate layer and results similar to the value of the lower layer. There is. Therefore, it was confirmed that it is effective to use a disk and squeeze the mold from above and below.

[Test 2] Next, the following tests were conducted in order to confirm the practicality of the tester of the present invention and to confirm the optimum weight weight and weight drop height. Weights of 1.3 kg and 3.5 kg are used, and the weight drop height is 60 cm and 4
The number of times of compaction was changed at 0 cm, and the engineering properties of the soil were observed by the change of compaction work.

First, the weight was 1.3 kg and the weight drop height was 60 cm. The reason why the weight drop height is 60 cm is 15 cm according to the calculation formula of the compaction work described above.
Based on the compacting work amount of 3 layers × 92 times compacting in the mold, the same compacting work amount is set. The test results are as shown in FIG.

From FIG. 5, changes in the optimum water content ratio and changes in the maximum dry density due to changes in the compaction work could be confirmed. However, even in each compacting work, since the compacting curve becomes sharp, the conventional test results are not reflected and it is difficult to adjust the water content ratio of the sample. Further, for the optimum water content, in order to obtain a value close to the value obtained by the compaction test using the 15 cm mold (3 layers × 92 times) which is a conventional test method, the compaction is performed 60 to 80 times. Is required,
This resulted in a problem in workability and an increase in the time required for the test.

Therefore, next, in order to reduce the number of times the weight is dropped and to satisfy the compaction work amount, the weight weight is increased to 3.5 kg, and the number of times of compaction is set using the above-mentioned formula. A similar test was conducted. The test results showing the relationship between the number of times of compaction, the optimum water content ratio and the dry density are as shown in FIG.

From FIG. 6, it can be seen that when the water content of the target soil is low, the dry density tends to be higher than before.
This is because the weight of the weight is increased and the amount of compaction work (including kinetic energy) is increased. As a result, the density tends to increase regardless of changes in the water content ratio. Since the amount is large, it is feared that it leads to the destruction of the skeleton of soil particles.

Based on the above results, the weight weight is 3.5.
The same test was conducted by reducing the weight drop height to 40 cm in kg. The test results showing the relationship between the number of times of compaction and the optimum water content ratio and dry density are shown in FIG. 7.

From FIG. 7, the tendency that the dry density became high when the water content ratio was low was eliminated, and the compaction curve and the optimum water content ratio were easily confirmed. It was also confirmed that the increase in dry density with the increase in the number of times of compaction shows a good value. Therefore, in this test, it is appropriate to perform the weight weight of 3.5 kg and the weight drop height of 40 cm.

[Test 3] Next, using the tester of the present invention, in order to confirm the number of times of compaction required to obtain the dry density equivalent to that of the conventional test method, the compaction work amount and the maximum dry density were confirmed. Regarding this relationship, a comparative test between the present invention and the conventional method was conducted.

By the way, JIS A 1210 and JSF T711-1990 are mainly applied to the compaction test method for soil by tamping. The number of times of compaction, the weight of rammer, and the number of compaction layers are also determined by this test method, and as a result, the compaction work amount is also determined. JIS A 1210 and JSF
Table 2 shows an excerpt of the compaction method specified in T 711-1990.

[0042]

[Table 2]

The compaction work by the above-mentioned compaction method can be calculated by the above-mentioned formula, but since the factors of the fall velocity and kinetic energy related to the fall of the rammer are not included, for example, the rammer drop height is 60 cm, Number of consolidations 2
5 times (Ec = 26.03) and Rammer drop height 40c
m and the number of times of compaction 37 times (Ec = 25.9) have almost the same compaction work amount, but the obtained optimum water content ratio and dry density have different values.

Further, when the tester of the present invention is compared with the conventional 15 cm and 10 cm mold testers, it is considered that an important factor is whether or not the side wall is restrained.

Therefore, the present test conditions are that the present invention has a weight weight of 3.5 kg and a weight drop height of 40 cm confirmed in the above test, and the number of weight drops is changed by using a mold having a diameter of 5 cm. 1 layer tamping test, conventional method is JSF
According to T 711-1990, 15 cm and 10 cm molds were used and the rammer weight was 4.5 kg. The test results are shown in FIG.

According to FIG. 8, whichever test method is used, the maximum dry density is increased due to the increase in the compaction work. However, when comparing the maximum dry densities with the same compaction work, the simple compaction tester of the present invention showed 0.05.
.About.0.1 g / cm @ 3, which is a high value. For example, as shown in the conventional test method, 3 layers × 92 times (EC = 25.3)
The maximum dry density is about 1.95 g / cm 3 when compacted with a mold having a diameter of 15 cm and a diameter of 01.
When compacted by the test method of the present invention using a mold having a diameter of 5 cm, a maximum dry density of about 2.02 g / cm 3 is shown.

This is because the compaction effect from the upper and lower surfaces of the specimen was obtained by compacting the mold from above and below, and at the same time, the mold diameter and the rammer diameter (moving piston and fixed piston diameter) were obtained. ) Is the same, it is considered that there are no lateral flows of the sample due to compaction and that the resistance due to friction can be reduced. As a result, the density in the specimen increases uniformly and the overall dry density also increases. Therefore, when the test is performed with the same compaction work as in the conventional test method, the dry density shows a high value due to the side restraint and the like.

Therefore, in order to obtain the maximum dry density equivalent to that of the conventional test method using this tester using a mold having a diameter of 5 cm, as shown in FIG. 8, the compacting work amount is about Ec = 13. Must be done at .0. It has a diameter of 5
When one layer is compacted using a cm mold, the number of compactions is about 13 to 15 times.

Next, the test method of the present invention and the JSF T of the conventional method are used.
FIG. 9 shows the results showing the relationship between the compaction work and the optimum water content by the test method of 711-1990. From this, in each case, it can be confirmed that the optimum water content ratio is changing low due to the increase of the compaction work amount, and at the same time, the simple compaction tester of the present invention has a certain compaction work amount as a whole. It can be seen that the optimum moisture content in the amount is lower than that in the conventional test conducted based on JIS A 1210 or JSF T 711-1990. It is considered that this is due to the structures of the mold and the bottom plate described above.

The optimum water content is the water content when the particles are packed in the mold at maximum density and when the voids are closest to zero. Therefore, it is necessary to sufficiently compact the sample in the mold, and as in the conventional test method, the density of the lower portion of the test piece cannot be increased by the compaction only from the upper surface.
Considering the relationship between the mold diameter and the diameter of the tampering rammer, in the case of the conventional test method, the rammer diameter is smaller than the mold diameter, so that the sample flows laterally during the tamping. Therefore, when trying to obtain the maximum density, it is conceivable that the optimum water content ratio becomes a high value due to the fact that a large amount of adhesive force is required due to the addition of water.

In the case of the simple compaction tester of the present invention, since the mold diameter and the rammer diameter (moving piston and fixed piston diameter) are the same, there is no fear of the sample laterally flowing during compaction. Further, since the compaction effect can be obtained from the upper surface and the lower surface of the specimen, the variation in the density within the specimen is reduced. It is believed that these factors are the reason for the decrease in the optimum water content compared to conventional test methods.

From the above, in the test method using the simple compaction tester of the present invention, the weight weight is 3.5 kg,
When the weight drop height is set to 40 cm, a good compaction curve and optimum water content ratio can be obtained. In addition, the number of compaction is 13
When it is set to -15 times, the maximum dry density equivalent to that of the conventional test method can be obtained.

[Test 4] Next, a test using cohesive soil using the tester of the present invention will be described. Table 3 shows the properties of cohesive soil. In addition, the test conditions are: weight weight 3.5 kg, weight drop height 40 cm, input sample 3
It is 50 g. The test results are as shown in FIG.

[0054]

[Table 3]

It can be seen from FIG. 10 that a good compaction curve can be confirmed and that there is a tendency corresponding to changes in the water content ratio and changes in the number of drops. However, when compared with the results obtained by the JIS test method, there is not much correspondence. These differences are large compared to the case of Masa soil.

When the masa soil and the cohesive soil are compared with each other, it is conceivable that the cohesive soil is more strongly laterally flowing than the masa soil, if the test is conducted by the JIS test method. However, the diameter is 5 cm
When the test is carried out by the simple compaction tester of the present invention using the mold of No. 1, there is almost no lateral flow.
Therefore, the compaction test performed by the JIS test method,
When comparing tests by the simple compaction tester of the present invention,
It can be seen that when a sample having a large lateral flow is used, the correlation with JIS becomes small, and conversely, when a sample having a small flow is used, the correlation with the JIS test result also becomes large.

The specimen produced by the simple compaction tester of the present invention has a height of 1.8 to 5 cm (diameter (5 cm)).
It is about 2.5 times, so this sample can also be applied to other mechanical tests and the like.

[0058]

As described above, in the simple compaction tester according to the present invention, the bottom plate provided with the cylindrical fixed piston is provided in the lower portion of the tester frame, and the fixed piston operates in the vertical direction. The cylindrical mold which is slidable with respect to the fixed piston is inserted into the cylindrical mold by covering the fixed piston from the lower side of the cylindrical mold. Is arranged so that it can move vertically in a vertical direction while sliding with respect to the fixed piston, and a movable piston that is slidable with respect to the cylindrical mold and has a piston rod of a desired length on the back is Insert from the upper side with the moving piston facing down and the piston rod facing up, and while the moving piston slides against the cylindrical mold, the moving piston and piston rod move vertically up and down. A weight that is arranged as much as possible and that has a substantially cylindrical shape and has a piston rod insertion hole formed in the axis is used so that the weight slides on the piston rod and collides with the back of the moving piston. Since it has been inserted into the piston rod insertion port of the weight, it can be compacted to a uniform density with a small number of compaction times, and the labor required for the test can be greatly saved, and the mold can be downsized to reduce the amount of sample required per sample. it can.

Further, since an automatic weight lifting and dropping mechanism is provided which automatically lifts the weight that is falling in contact with the back surface of the moving piston and automatically drops it from a desired height, The required sample can be obtained in a short time without any trouble.

Further, the compaction test method by tamping according to the present invention uses the simple compaction tester of the present invention, the sample is 350 g, the inner diameter of the cylindrical mold is 5 cm, and the weight of the weight is 3.5 kg. And the drop height of the weight is 40
Since it is performed in cm, a good compaction curve can be obtained, and the optimum water content ratio can be easily confirmed.

Further, when the weight is dropped 13 to 15 times, almost the same result as the conventional test method can be obtained, and the conventional data can be applied as it is.

[Brief description of drawings]

FIG. 1 shows an example of a conventional tester, (A)
Is a front view and (B) is a partially enlarged view.

FIG. 2 is a graph showing the results of a compaction test on soil by compaction at various compacting workloads.

FIG. 3 is a front view showing an embodiment of the simple compaction tester of the present invention.

FIG. 4 is an explanatory view showing a usage state of the simple compaction tester of FIG. 3, (A) showing before compaction and (B) showing after compaction.

FIG. 5 is a graph showing compaction test results when a 1.3 kg rammer is used. (Drop height 60 cm)

FIG. 6 is a graph showing compaction test results when a 3.5 kg rammer is used. (Drop height 60 cm)

FIG. 7 is a graph showing compaction test results when a 3.5 kg rammer is used. (Drop height 40 cm)

FIG. 8 is a graph showing the relationship between compaction work and maximum dry density.

FIG. 9 is a graph showing the relationship between the compaction work amount and the maximum water content ratio.

FIG. 10 is a graph showing the results of a simple compaction test using cohesive soil.

[Explanation of symbols]

1 bottom plate 2 frame 3 fixed piston 4 Cylindrical mold 5 guide rod 6 guide members 7 Moving piston 8 piston rod 9 guide 10 weights 11 Piston rod insertion port 12 Locking part 13 sprockets 14 rotation axis 15 chains 16 Support 17 Support pin 18 spring 19 Support bar 20 open claws 21 Spacer disc A Rammer axis B Rammer support rubber C notch D pulley E Rammer F spacer disk G mold

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyotaka Kuno 2-6-18 Takasago, Chuo-ku, Fukuoka-shi, Fukuoka Within Nishi Japan Research Institute (72) Genichi Sugihara 2-chome, Takasago, Chuo-ku, Fukuoka-shi, Fukuoka No. 6-18 West Japan Research Institute (72) Inventor Noritaka I, 2-6-18 Takasago, Chuo-ku, Fukuoka-shi, Fukuoka (72) Inventor Naoko Maeda Chuo-ku, Fukuoka-shi, Fukuoka Takasago 2-6-18 West Japan Research Institute Co., Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 3/00 E02D 1/02 JISST file (JOIS)

Claims (5)

(57) [Claims] 1. A bottom plate provided with a cylindrical fixed piston is provided in a lower portion of a frame of a testing machine so that the acting direction of the fixed piston is vertical and slidable with respect to the fixed piston. Insert the fixed mold into the cylindrical mold by covering the fixed mold from the bottom side of the cylindrical mold, and slide the cylindrical mold vertically with respect to the fixed piston. The movable piston, which is slidable with respect to the cylindrical mold and has a piston rod of a desired length on the back surface, is inserted from the upper side of the cylindrical mold so that the movable piston is on the lower side and the piston rod is on the upper side. At the same time, the moving piston and piston rod are arranged so that they can move up and down in the vertical direction while the moving piston slides on the cylindrical mold. So that the weight slides on the piston rod and collides against the back of the moving piston.
A simple compaction tester characterized by inserting the piston rod into the piston rod insertion port of the weight. 2. An automatic weight lifting and dropping mechanism for automatically lifting a weight that is falling in contact with the back surface of the moving piston and automatically dropping the weight from a desired height. The simple compaction tester described in 1. 3. The automatic weight lifting and dropping mechanism has a rotary shaft having chain driving sprockets on the left and right sides of a piston rod at the upper and lower positions of the testing machine frame, with the rotary shaft on the rear side of the piston rod. Arrange them respectively, hang the chain between the upper and lower sprockets on the left and right sides, and drive the rotating shaft with a motor so that the front chain rotates from bottom to top. Arrange the supporting parts for supporting the weight respectively at any position to
This support part is provided with a locking pin that is detachable from the locking part formed on the weight, the locking pin is movable in the horizontal direction, and the locking pin is usually located closer to the weight than the supporting part. A support bar for mounting an open claw that can be fixed at an arbitrary position with respect to the piston rod is provided by urging it with a spring so as to pop out and lock the locking portion of the weight, and both left and right ends of the support bar are provided. Attach an open pawl that forms a taper surface that faces inward from the outside downward and is tapered downward, and the chain rotates and the support part rises from the bottom so that the locking pin engages with the locking part of the weight. Then, as the support rises, the weight is also pulled up by the locking pin, and when the locking pin rising from below comes into contact with the open claw of the support bar fixed at the desired position of the piston rod, the locking pin Is pushed toward the support part along the tapered surface of the release claw and the locking pin 3. The simple compaction according to claim 2, wherein when the weight is pushed in until the engagement with the engaging portion of the weight is released by the opening claw, the weight automatically falls and collides with the back surface of the moving piston. testing machine. 4. Using the simple compaction tester according to claim 1, claim 2 or claim 3, using a sample of 350 g, an inner diameter of the cylindrical mold of 5 cm, and a weight of 3.5 kg.
A compaction test method by tamping, characterized in that the drop height of the weight is 40 cm. 5. The compaction test method by tamping according to claim 4, wherein the weight is dropped 13 to 15 times.