JPH025846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cast pipe equipped with a slurry launch height and density measuring device using an ultrasonic densitometer.

In general, various civil engineering works such as pour-in-place method, filling of voids, and placing concrete underwater, etc.
BACKGROUND ART In construction work, materials such as concrete, grout, and soil (hereinafter referred to as pouring materials) are poured at predetermined positions below the water surface using tremie pipes, grout hoses, and the like. When pouring such a pouring material, water or muddy water in the pouring area and the pouring material are replaced by the difference in their densities; If these are mixed, the strength of the pouring material will decrease and its quality will deteriorate. If there is a dense substance (e.g. slime) at the bottom of the water or muddy water and the difference in density between these substances and the pouring material is small, the tip of the pouring pipe will be able to fully penetrate into the pouring material. Occurs when it is not connected. For this reason, it is especially necessary for quality control to check whether the above conditions are met.

Therefore, conventionally, in order to check the presence or absence of slime, etc. described above, a plumber is used, the weight is lowered into the water, the contact between the weight and the slime, etc. is sensed, and this is determined based on the depth reached by the weight. Alternatively, they can attach a conductivity meter to a cord and suspend it in the water, and check for changes in resistance using this conductivity meter to check for slime, etc. In addition, in order to confirm the matters described above, use a plumber to lower the weight into the pouring pipe, sense the contact between the weight and the top of the pouring material, and check the depth reached by the weight. You can either check the position of the pouring material, or attach a thermistor to a cord and lower it into the pouring pipe, and use the temperature difference between water, muddy water, and the pouring material to measure the temperature of the pouring material with the thermistor. Checking location.

However, it is not easy to check the presence of slime in the water and the location of the pouring material, and conventional methods have poor measurement accuracy, and the density can be measured to determine the presence of slime and the location of the pouring material. Even when trying to confirm the position by density difference, there were drawbacks such as the inability to measure the density of slime, etc. in the water.

By attaching two ultrasonic density meters to the outer periphery of the cast pipe, spaced apart in the axial direction of the cast pipe,
These ultrasonic density meters can measure both the absolute value of the density at the point where it is installed and the density distribution along the axial direction of the poured pipe. It is possible to accurately and easily measure both the amount of slurry and the launch height of the pouring material in water, and the launch height and launch height of the slurry that can prevent a decrease in strength and quality deterioration of the cast material. The object of the present invention is to provide a cast pipe with a density measuring device.

Hereinafter, one embodiment of the present invention will be described based on the drawings. Reference numeral 1 in FIG. 1 is a pouring pipe for concrete, grout, etc., and brackets 2 and 3 are provided on the outer periphery of the lower end of this pouring tube 1, spaced apart in the circumferential direction. An ultrasonic density meter 4 is attached to the. This ultrasonic density meter 4
The ultrasonic oscillator (sensor part) 5 attached to one bracket 2 and the other bracket 3
It consists of an ultrasonic receiver (sensor section) 6 that is attached to the ultrasonic transducer and receives ultrasonic waves emitted from the ultrasonic oscillator. The ultrasonic oscillator 5 and the ultrasonic receiver 6 are opposed to each other, and the distance between them is 50 mm to 100 mm.
It is said that Furthermore, polytetrafluoroethylene coatings 7, 7 are applied to opposing surfaces (inner surfaces) of the ultrasonic oscillator 5 and the ultrasonic receiver 6, respectively.

The brackets 2 and 3 each consist of protective plates 8 and 9 formed by inclined plates provided to surround the ultrasonic oscillator 5 and the ultrasonic receiver 6 from the outside except for their opposing surfaces. .

Furthermore, brackets 10 and 11 are provided on the outer periphery of the casting pipe 1 at appropriate distances from the ultrasonic density meter 4 in the axial direction of the casting pipe 1. An ultrasonic density meter 12 is attached to these brackets 10 and 11. This ultrasonic density meter 12 has the same configuration as the ultrasonic density meter 4, and includes an ultrasonic oscillator 13 located directly above the ultrasonic oscillator 5 and attached to a bracket 10, and an ultrasonic receiver. 6 and an ultrasonic transducer 14 attached to a bracket 11 located directly above the ultrasonic transducer 6. Also, the facing surface (inner surface) between the ultrasonic oscillator 13 and the ultrasonic receiver 14
are coated with polytetrafluoroethylene coatings 7, 7 similarly to the ultrasonic transducer 5 and the ultrasonic receiver 6. Note that the bracket 2 and the bracket 3 are formed symmetrically, and the bracket 2 and the bracket 10 have the same configuration.
Bracket 3 and bracket 11 have the same structure.

The ultrasonic transducer 5, 13, the ultrasonic receiver 6,
14 has codes 15, 17, 16, 18 respectively
are attached, which extend upwardly along the outer peripheral surface of the casting pipe 1 through the protection plates 8 and 9, and are electrically connected to the channel control 19. The channel control 19 is electrically connected to an amplifier 20, and the amplifier 20 is electrically connected to a recorder 21.

Next, the case of pouring concrete, grout, etc. will be explained. In addition, FIG. 5 is an ultrasonic attenuation state diagram of the ultrasonic densitometer, and FIG. 6 is a usage state diagram of the ultrasonic densitometer. The broken line graph in FIG. 5 shows the attenuation state of ultrasonic waves from the ultrasonic density meter 4 located at the lower end of the pouring pipe 1, and the solid line graph in FIG. Each shows the attenuation state of the sound wave. Further, in FIGS. 5 and 6, 1 shows a state in which slime is detected and removed, 1 shows a state in which pouring is started, 1 shows a state in which pouring is progressing, and 1 shows a state in which the pouring pipe 1 is pulled up.

(1) First, check whether there is slime in the water. To do this, as shown in FIG. 6, the casting pipe 1 is set in a predetermined position underwater, and the ultrasonic density meters 4 and 12 are activated. The ultrasonic density meters 4 and 12 are configured to measure the ultrasonic densities of the ultrasonic oscillators 5 and 13 when the ultrasonic waves emitted from the ultrasonic oscillators 5 and 13 are transmitted to the ultrasonic transducers 6 and 14.
Utilizing the fact that the amount of attenuation of ultrasonic waves changes depending on the density of the material existing between the ultrasonic transducers 6 and 14, the density of the material can be directly measured from the amount of attenuation of the ultrasonic waves. The attenuation value of such ultrasonic waves is code 15, 16, 17,
18, channel control 19, amplifier 2
0 is recorded on the recorder 21. Therefore,
When slime S exists between sensor parts 5 and 6 in water W, slime S has a higher density than water W as described above, so ultrasonic density meter The attenuation value of the ultrasonic waves of No. 4 becomes high. On the other hand, sensor section 1
Since only water exists between 3 and 14, the attenuation value of the ultrasonic waves from the ultrasonic density meter 12 does not change and remains at a low value as shown in the solid line graph in FIG. Therefore, in this case, the slime in the water is removed until the value of the ultrasonic density meter 4 becomes approximately equal to the value of the ultrasonic density meter 12.

(2) Next, start pouring in this state. Then,
When the pouring material slurry G comes into contact with the ultrasonic density meter 4, the attenuation value of the ultrasonic waves of the ultrasonic density meter 4 suddenly increases, as shown in the dashed line graph in FIG. That is, as described above, the amount of attenuation of the ultrasonic wave is between the sensor parts 5 and 6 and between the sensor part 1.
Since it is proportional to the density between 3 and 14, the density of the slime can be known in (1) above, and the density of the pouring material slurry G after pouring can be known in (2) above. If the density of the pouring material slurry G is less than a predetermined value, it is considered that the pouring material slurry G and water are mixed, and it is understood that corrective action must be taken as soon as possible.

(3) In (2), if the density of the ultrasonic density meter 4 shows a predetermined value, the pouring is continued. When the pouring material slurry G reaches between the sensor parts 13 and 14, the attenuation value of the ultrasonic waves from the ultrasonic density meter 12 increases and becomes approximately the same as the attenuation value of the ultrasonic waves from the ultrasonic density meter 4. When the attenuation values of the ultrasonic waves of the ultrasonic density meters 4 and 12 become approximately the same, pouring of the pouring material slurry G is stopped.

(4) Now, as shown in FIG. 6, pull up the casting pipe 1 until the tip of the casting pipe 1 is located at a predetermined position. Then, the pouring material slurry G disappears between the sensor parts 13 and 14 of the ultrasonic densitometer 12, so the attenuation value of the ultrasonic waves of the ultrasonic densitometer 12 decreases. Therefore, we restarted pouring. After this, the above
By repeating the operations (2), (3), and (4) as necessary, the required height of pouring is completed without reducing the strength of the pouring material slurry G.

As explained above, according to the present invention, by attaching two ultrasonic densitometers to the outer periphery of the cast pipe at a distance in the axial direction of the cast pipe, the density at the point where these ultrasonic densitometers are attached is It is possible to measure both the absolute value of and the density distribution along the axial direction of the cast pipe. As a result, before slurry pouring, it becomes possible to measure the presence or absence of slime in the water and the amount of slime remaining therein, thereby ensuring that the slime can be treated reliably. on the other hand,
When pouring slurry, one of the ultrasonic density meters mentioned above is attached to the tip of the pouring pipe, so the height of slurry pouring and the positional relationship with the pouring pipe can be constantly monitored. While measuring, it becomes possible to pour slurry with the tip of the pouring pipe buried in the slurry. Moreover, since the height of the slurry is measured based on the density difference, the measurement accuracy is high even when there is no temperature difference between the slurry and the water, and the height of the slurry can be detected. It is suitable for Furthermore, since the absolute value of the density of the slurry itself can be measured during slurry pouring, the density of the slurry,
That is, the pouring work can be performed while checking and controlling the mixing of water into the slurry. In addition, the sensor part of the ultrasonic density meter is coated with polytetrafluoroethylene, which prevents the pouring material (slurry) and slime from adhering to the sensor part, resulting in more accurate slurry casting. It becomes possible to measure the height and its density. This is useful in cases where it is necessary to always perform accurate density measurements even if the measurement environment suddenly changes, such as when measuring the slurry launch height and its density while pulling up the pouring pipe, as described above. This is an extremely important effect. Furthermore, since the outside of the ultrasonic density meter is protected by a protective plate, obstacles such as reinforcing bars submerged in the water will not get caught in the ultrasonic density meter, and slurry such as vertical movement of the pouring pipe will not be caught. Pouring work can be performed smoothly.

[Brief explanation of drawings]

FIG. 1 is a partially omitted front view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1,
3 is an enlarged sectional view of the circular part in FIG. 2, FIG. 4 is a sectional view taken along the - line in FIG. 1, and FIG. FIG. 6 is a diagram showing how the ultrasonic density meter of the present invention is used. 1... Casting pipe, 4, 12... Ultrasonic density meter,
5, 13... Ultrasonic oscillator (sensor part), 6,
14... Ultrasonic transducer (sensor part), 7... Polytetrafluoroethylene coating, 8, 9
...Protection board.

Claims (1)

[Claims] 1. Two ultrasonic density meters are attached to the outer periphery of the cast pipe at a distance in the axial direction of the cast pipe, and
One of the ultrasonic density meters is attached to the tip of the casting pipe, and the sensor portion of the ultrasonic density meter is coated with polytetrafluoroethylene. A casting pipe with a device for measuring the height and density of slurry, characterized in that the casting pipe is protected by a protective plate surrounding the outside and is attached to the casting pipe.