JPH04363408A - Water bottom original position soil nature test device - Google Patents

Abstract

PURPOSE:To provide a test device at an original position on soft water bottom nature soil without destroying its bottom mud and perform soil nature testing at the original position. CONSTITUTION:At appropriate positions at a ballast tank 3 provided coveringly over a soil nature tester, valve devices that conduct freely underwater weight adjustment as to the ballast tank 3, such as plural fixed valves 4A, 4B, 4C to regulate a ballast tank 3 inside air quantity at a predetermined maximum value and valves 7A, 7B to conduct the injection and discharge of compressed air into and out of the ballast tank 3 by remote control, are equipped.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an in-situ underwater soil testing device that can measure in-situ the strength of soft bottom soil deposited mainly in inner bays, rivers, lakes, etc. .

0002

[Prior art] In recent years, harmful bottom soil at the bottom of the water is covered with sand.
The elution of harmful substances is prevented by containing them, but in order to determine the thickness of sand covering, it is necessary to know the strength of the bottom soil. Therefore, conventionally, the strength measurement of bottom soil at the bottom of water has been carried out by laboratory tests using samples sampled with a sampler, etc., but the disturbance of the sample due to sampling affects the measured value, making it difficult to know the exact strength. The problem was that I couldn't do it.

[0003] In addition, in the current soil testing method, the rotational torque of the vane emperor at the tip of the penetrating rod is detected,
JIS and other regulations specify the use of vane testing machines that measure strength based on the resistance of the soil, and cone penetration testing machines that measure the penetration resistance of cones into soil. Even if an attempt was made to conduct a soil test, there was a problem in that when the testing machine was installed on the bottom soil, the bottom soil would be destroyed by the weight of the testing machine, making it impossible to perform the test.

0004

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an in-situ product on the bottom soil of a soft water bottom without destroying the bottom soil. The object of the present invention is to provide an in-situ soil testing device at the bottom of the water that can be installed in water and perform in-situ soil testing.

[0005]

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the in-situ underwater soil testing device of the present invention is installed over a soil testing machine such as a vane testing machine or a cone penetration testing machine. It is constructed by equipping a ballast tank with a valve device that can freely adjust the weight in the water. In addition to providing a plurality of fixed valves for regulation, it is preferable to equip a valve device consisting of an electromagnetic valve or the like that can remotely control the injection and discharge of compressed air into the ballast tank.

[0006] In the above device, the underwater weight of the entire device is appropriately reduced depending on the amount of air in the ballast tank covering the soil tester, and since the underwater weight can be adjusted by remote control, the soil tester can be easily adjusted. can be carried out in situ on the sediment without destroying the sediment.

[0007]

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a side sectional view of the whole of an in-situ soil testing device on the water bottom in one embodiment. A plurality of fixed air vent valves are installed at appropriate positions on the side of a ballast tank 3 that covers a soil testing machine such as a penetration testing machine 2 to regulate the amount of air in the ballast tank 3 to a predetermined maximum value. 4A, 4B, and 4C are provided.

That is, these air vent valves 4A, 4
The mounting positions of B and 4C are based on the minimum underwater weight of the device itself including these ballast tanks 3, such as 60 kgf (valve 4A), 120 kgf (valve 4B), 180 kgf (
Valve 4C) is set up, and its operation is to manually open and close the device before landing on the water, and the underwater weight is reduced according to the amount of air in the ballast tank 3. In the figure, 5 indicates an open hole. The open hole 5 is provided at a position where the underwater weight becomes 0 kgf when the valves 4A, 4B, and 4C are closed and filled with air.

Next, this ballast tank 3 includes an electromagnetic valve 7A as a valve for injecting compressed air from the compressor 6 into the ballast tank 3.
There is an electromagnetic valve 7B as a valve for discharging the compressed air inside, and it can be remotely operated via a remote monitoring and control device 8 and a control device 9. That is, the ballast tank 3
In order to freely control the adjustment of the underwater weight of the main body of the device including 4A
, 4B, 4C open and close to discharge air, and an adjustment means that remotely controls solenoid valves 7A, 7B to open and close solenoid valves 7A, 7B to inject and discharge compressed air. This embodiment does this.

Next, when the apparatus shown in FIG. 1 is submerged in water, FIG. 2 shows how the weight of the apparatus itself changes in water depending on the opening and closing positions of the air vent valves 4A, 4B, and 4C. ■ in Figure 2 opens only the air vent valve 4C, ■ opens only the air vent valve 4B, and ■ indicates air vent valve 4A.
Open only the air vent valves 4A, 4B, 4.
The ground pressure of the bottom plate 10 of this device shown in FIG. 1 is shown on the right side of the figure.

That is, when the main body of the device is submerged in water, the air in the ballast tank 3 is compressed by the water pressure.
The underwater weight increases, but as shown in FIG. 2, the increase in the underwater weight draws a gentle curve as the water depth becomes deeper. When the electromagnetic valves 7A, 7B are not remotely operated, the underwater weight is calculated from the opening/closing position of each air vent valve 4A, 4B, 4C and the water depth.

Next, if you want to keep the underwater weight constant regardless of the water depth, the compressed air is adjusted.
Select the air vent valve 4A, 4B, or 4C whose weight you want to keep constant, and open the air vent valve (4A, 4B, or 4C) at that position in advance. When compressed air is injected into the ballast tank 3 after settling to a predetermined water depth, the compressed air enters up to the opened air vent valve (4A, 4B, or 4C), and any further air is discharged from the air vent valve.

FIG. 3 shows all the air vent valves 4A, 4B,
It shows the change in weight underwater when 4C is closed and submerged to a depth of 20 meters and compressed air is forcibly injected.
The operation is performed in the following steps. First, all the air vent valves 4A, 4B, and 4C are closed, and the water is filled with air up to the position of the open hole 5, and the water is landed on the water.At this time, the underwater weight is 0 kgf, and then the water depth is set to
It is allowed to sink to 0 m, but its weight in the water increases as it sinks. When compressed air is injected into the ballast tank 3 at a depth of 20 m, the compressed air fills up to the open hole and the underwater weight decreases to 0 kgf.

Next, FIG. 4 shows the change in the underwater weight due to the adjustment of the air amount by submerging to a depth of 20 m and injecting compressed air when the air vent valve 4A is opened. Furthermore, Figure 5 shows the water depth of 20 when the air vent valve 4B is opened.
Figure 6 shows the change in underwater weight due to the injection of compressed air after sinking to a depth of 4C.
The figure shows the change in weight underwater when the vessel is opened to a depth of 20 meters and compressed air is injected into the vessel.

Next, in FIG. 7, the test device is not grounded directly above the bottom soil measurement position, but the bottom plate 10 is extended on both sides so that the reaction force is obtained at a slightly distant position, and the bottom plate 10 is grounded at both ends. It is a lower part side view of the underwater in-situ soil test device of another Example with plate 10A attached. In the drawing, the stress bulb produced by this test device is indicated by a broken line S, and since the lower end of each soil test device does not come into direct contact with the sediment during settling, there is no stress increase at the measurement position or the influence of disturbance. This has the advantage of improving stability against water flow, waves, etc.

[0016]

Effects of the Invention According to the underwater in-situ soil testing device of the present invention as described above, the underwater weight of the device body can be adjusted by an appropriately equipped valve device. It has the advantage of being able to install a soil tester using an in-situ testing device without destroying the soil, and it is possible to conduct tests without disturbing the sediment in situ, so accurate soil strength can be obtained. effective.

[0017]

[Brief explanation of drawings]

FIG. 1 is an overall side cross-sectional view of an in-situ soil testing device at the bottom of water in an embodiment of the present invention.

FIG. 2 is a diagram showing changes in underwater weight depending on the opening/closing position of the air vent valve of the device in FIG. 1;

FIG. 3 is a diagram showing changes in underwater weight due to compressed air adjustment when all air vent valves of the device in FIG. 1 are closed;

4 is a diagram showing changes in underwater weight due to compressed air adjustment when the air vent valve 4A of the device shown in FIG. 1 is open; FIG.

5 is a diagram showing changes in underwater weight due to compressed air adjustment when the air vent valve 4B of the device in FIG. 1 is open; FIG.

6 is a diagram showing changes in underwater weight due to compressed air adjustment when the air vent valve 4C of the device in FIG. 1 is open; FIG.

FIG. 7 is a lower side view of an in-situ soil testing device on the bottom of water according to another embodiment of the present invention.

[Explanation of symbols]

1... Vane testing machine, 2... Cone penetration testing machine, 3...
Ballast tank, 4A, 4B, 4C...Air vent valve, 7A, 7B...Solenoid valve, 8...Remote monitoring and control device, 9...Control device

Claims (1)

[Claims] [Claim 1] An in-situ soil testing device at the bottom of the water, which is equipped with a valve device that allows the underwater weight to be freely adjusted in a ballast tank installed over the soil testing device.