JPH0428853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tremie pipe tip position measuring device for underwater concrete pouring.

The most commonly used method for placing underwater concrete is the so-called tremie method, in which a hollow cylindrical tremie pipe is installed in advance, and concrete is poured from the upper end of the pipe through a hopper.

In this construction method, the positional relationship between the concrete placed underwater and the tip of the tremie pipe is an important point.

That is, if the tip of the tremie tube penetrates deeply into the poured concrete and the concrete surface inside the tube is too high, the poured concrete will not flow down the inside of the tube.

On the other hand, if the tip of the tremie tube does not penetrate too deeply into the poured concrete, but only slightly intrudes from the surface of the poured concrete, the poured concrete will rapidly flow down the tube and erupt from the tip, causing the concrete to It not only separates and deteriorates quality after curing, but also pollutes rivers and oceans.

In particular, if concrete is placed with the tip of the tremie tube separated from the concrete surface, the concrete will fall freely in the water and separate more violently.

Therefore, in the tremie pipe method, the reliability of the method may be affected if the concrete surface and the tip of the tremie pipe are not constructed while maintaining the specified positional relationship.
Prevention of environmental pollution could not be ensured.

For this reason, in the past, the height of poured concrete was estimated from the relationship between the amount of concrete poured and the area to be poured, and the positional relationship between the tip of the tremie pipe and the surface of the poured concrete was determined by comparing it with the installed tremie pipe length. Was.

In this case, it was also necessary to suspend heavy weights from the water surface and measure the height of the concrete surface.

However, the concrete surface placed underwater,
Because the site is not flat, it is uneven, and there are reinforcing bars installed, so the measurement results or estimates using the methods described above were insufficient to ensure the reliability of the construction method.

Furthermore, recently, a new type of underwater concrete has been developed and put into practical use, in which a special admixture is added to poured concrete to suppress separation in water, but this underwater concrete has a high viscosity and is less fluid than poured concrete. is small.

Therefore, in order to make pouring smooth, it is necessary to adjust the positional relationship between the tip of the tremie tube and the surface of the concrete to be poured so that the tip of the tremie tube slightly penetrates, thereby promoting the flow of concrete within the tube.

In addition, when placing concrete while moving the tremie pipe horizontally, it is necessary to separate it slightly, so the positional relationship between the tip position of the tremie pipe and the concrete surface to be poured must be grasped more accurately and quickly. However, the conventionally employed devices were insufficient for this purpose.

This invention was made in view of the above problems, and its purpose is to quickly and reliably grasp the positional relationship between the tip of the tremie pipe and the surface of poured concrete. An object of the present invention is to provide a device for measuring the tip position of a tremie pipe for underwater concrete placement, which can ensure reliability of construction by using the device.

In order to achieve this objective, the present invention aims to reduce the temperature of concrete with respect to the water temperature at the pouring point by
Normally, the height is higher due to the frictional heat inside the concrete during transportation and the hydration heat of the cement, and this phenomenon is used to measure the difference in these temperatures to determine the concrete placement height. a measuring rod that is provided along the side surface of the tip of a hollow cylindrical tremie tube for underwater concrete pouring, and a portion of which protrudes downward from the tip of the tremie tube; A measuring rod is provided with a plurality of temperature sensors arranged stepwise in an extending direction at required intervals from a position above the tip to a position below the tip; and a measurement rod electrically connected to the temperature sensor and measuring the temperature. The present invention is characterized by comprising an arithmetic processing unit that calculates the positional relationship between the tip of the tremie pipe and the underwater concrete placed through it based on the temperature detected by the sensor.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows the overall configuration of a device for measuring the tip position of a tremie tube for underwater concrete placement according to the present invention, and this device includes a measuring rod 12 attached to a tremie tube 10 for underwater concrete pouring, and a measuring rod 12 attached to a tremie tube 10 for placing underwater concrete. It is generally composed of twelve temperature sensors 14 and an arithmetic unit 16 that is electrically connected and placed on the ground.

The tremie pipe 10 has a hollow cylindrical shape, and a hopper 18 for charging underwater concrete that expands upward is attached to the upper end, and the tip has a tapered shape with a reduced diameter.

The measuring rod 12 is made of corrosion-resistant acrylic,
It is molded from stainless steel or the like, and a part thereof protrudes downward from the tip 10a of the tremie tube 10, and is fixed along the side surface with a mounting band 20. A plurality of temperature sensors 14a, 14b, . Each temperature sensor 14 is connected to the arithmetic processing unit 1 via a captire cable 22 disposed along the side surface of the tremie tube 10.
6.

The temperature sensor 14 is specifically composed of a thermocouple, and one junction point where dissimilar metals are joined is
Temperature compensation is performed by applying a predetermined reference voltage, etc., and thermocouples are suitable because of their quick response.

The arithmetic processing unit 16 includes an automatic multi-point switch 24 that sequentially and individually extracts the measured values detected by each temperature sensor 14a, 14b, etc., and converts the temperature measurement values extracted by the switch 24 into digital signals. An A/D converter 26 for conversion, a CPU unit 28 for processing the converted signal based on a preset program, and a plotter 30 and printer 32 for displaying and recording the results processed by the CPU unit 28. It is configured.

Next, a description will be given of how to use the apparatus for measuring the tip position of a tremie pipe for underwater concrete placement according to the present invention having the above-described configuration.

Fig. 2 shows how to use the device, and Fig. 2a shows a state in which the tip 10a of the tremie pipe 10 has penetrated to a predetermined depth (h ₁ ) into concrete 34 placed in water via the tremie pipe 10. Concrete in condition 34
Figure b shows a case in which the tip 10a of the tremie pipe 10 is separated from the surface of the concrete 34 by a predetermined distance (h ₂ ). This shows the case where concrete is difficult to separate in water).

In either case, poured concrete 3
The positional relationship between the tip 10a of the tremie pipe 10 and the surface of the poured concrete 34 is determined by detecting the difference in temperature between the temperature sensor 14 in the tremie pipe 10 and the temperature sensor 14 in the water.

To explain specifically, first, the measured values of each temperature sensor 14 disposed on the measuring rod 12 are
The values are sequentially fetched into the CPU unit 28 via the automatic multi-point switch 24 and the A/D converter 26, and stored. Next, from the concrete temperature Tc immediately before pouring and the temperature deviation △Tc in the concrete, a preset temperature range, that is, Tc−△Tc<Ti
＜Tc＋△Tc (here Ti is the temperature at any measurement point)
Measurement points that satisfy the following criteria are selected using a pre-installed program. A measurement point that satisfies this condition is considered to be in the poured concrete 34. Thereby, the position of the surface of the poured concrete 34 can be determined to be between the measurement point with the highest value that satisfies the above temperature range and the measurement point above it.

Then, the length of the measuring rod 12 (l ₁ ), the protruding length from the tremie tube 10 (l ₂ ), and each temperature sensor 1
The interval (l ₃ ) between 4a, 14b... is different,
If these values are stored in the CPU unit 28, the positional relationship between the tip 10a of the tremie tube 10 and the surface of the poured concrete 34 can be calculated, and the results can be sent to the plotter 30 or printer 3.
It can be displayed on 2.

Furthermore, when this device is applied to the construction method shown in _FIG . If we display the upper part as positive and the lower part as negative, we get
If the construction is normal when the tremie pipe 10 is pulled upward, the surface of the poured concrete 34 measured as described above will always show a positive value, but if the amount of lifting becomes large, It becomes a negative value, and construction errors can be immediately detected.

As described above in detail in the embodiments, the apparatus for measuring the tip position of a tremie pipe for underwater concrete placement according to the present invention includes a sensor 14a for temperature measurement,
The measuring rods 12, which are vertically arranged in steps, are provided so that a part of them protrudes downward from the tip of the tremie tube 10. It can be applied not only when construction is performed by penetrating concrete, but also when construction is performed with the tip separated from the concrete surface without any modification to the equipment.

The results measured by each temperature sensor 14a, 14b... are then processed by the arithmetic processing unit 16, so that the positional relationship between the poured concrete surface and the tip of the tremie pipe 10 is quickly and accurately measured and understood quantitatively. It becomes possible to do so.

For these reasons, underwater concrete is placed according to the settings without separating the concrete, the concrete strength of the formed underwater structure is ensured, and the reliability of construction can be maintained.

Furthermore, since the temperature measurement value is converted into a digital quantity for calculation processing, the output signal from the CPU unit 28 can be easily used, for example, when automatically controlling the elevation or horizontal movement of the tremie tube 10. , can be automated immediately.

[Brief explanation of drawings]

FIG. 1 is an overall view of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of how to use the measuring device of the present invention. 10...Tremy tube, 10a...Tip, 12...
...Measuring rod, 14...Temperature sensor, 16...
Arithmetic processing unit, 18... hopper, 20... mounting band, 22... captire cable, 2
4... Automatic multi-point switch, 26... A/D converter,
28...CPU unit, 30...Protector, 3
2...Printer, 34...Concrete.

Claims (1)

[Claims] 1. A measuring rod provided along the side surface of the tip of a hollow cylindrical tremie tube for underwater concrete pouring, with a portion of the rod protruding downward from the tip of the tremie tube, and a measuring rod fixed to the measuring rod that extends from the tip of the tremie tube. A plurality of temperature sensors arranged vertically at required intervals from a position above the tip to a position below the tip; A tremie pipe tip position measuring device for placing underwater concrete, comprising an arithmetic processing unit that calculates the positional relationship between the tip of the tremie pipe and underwater concrete placed through the tremie pipe tip.