JP3713603B2 - Method and apparatus for monitoring injection status of injection solution - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for monitoring an injection state of an injection solution such as cement milk or a chemical solution in a foundation method using a steel pipe pile or the like.
[0002]
[Prior art]
Generally, the foundation method using a steel pipe pile is a method of drilling the ground in advance with an earth auger, etc., and placing the steel pipe pile in it, or setting the earth auger in the steel pipe pile and drilling the hollow part In this method, the piles are sunk. In order to compensate for the decrease in pile bearing capacity caused by the gap between the steel pipe pile and the ground, the gap is filled with an injection solution such as cement milk.
[0003]
By the way, since the gap between the steel pipe pile and the ground is usually filled with muddy water, it is difficult to monitor the liquid level, that is, the injection state when injecting cement milk having a higher specific gravity. It was.
[0004]
In order to solve this, conventionally, as shown in FIG. 5, an electric conductivity meter or a metal electrode P is inserted into the injection hole H of the cement milk M, and according to the cement milk M, the muddy water D, or a mixed liquid MD thereof. There was a method and apparatus for measuring the measured electrical conductivity with the ground data logger R via the cable K.
[0005]
[Problems to be solved by the invention]
However, the above-described conventional measurement method and apparatus use alternating current, so that the measurement equipment becomes expensive, and it takes time to develop an appropriate measurement frequency, etc. There were also problems such as that it took time to produce.
[0006]
The present invention has been made to solve the above-described conventional problems. The object of the present invention is to be able to use an inexpensive electrode and to perform reliable and highly accurate measurement to improve work efficiency. An object of the present invention is to provide a method and an apparatus for monitoring an injection state of an injection solution.
[0007]
[Means for Solving the Problems]
In the method for monitoring the injection state of the injection liquid of the present invention , a plurality of electrodes are arranged at appropriate intervals in the vertical direction in a space drilled in the ground, and a strong alkaline injection liquid such as cement milk is placed in the space. The injection state is monitored by measuring the change in potential difference between the electrodes as the liquid level rises . The electrode is a metal electrode such as a zinc electrode or a magnesium electrode, or a carbon electrode, and the change in the potential difference is monitored by a monitor.
[0008]
The injection state monitoring device of the injection solution of the present invention is a device for monitoring the injection state of a strong alkaline injection solution such as cement milk injected into the space drilled in the ground , a non-conductive rod, A sensor comprising a plurality of electrodes that are arranged at appropriate intervals in the vertical direction along the bar, and that measure a change in potential difference as the injection liquid level rises, and lead wires connected to the electrodes. And a data logger connected to the other end of each lead wire. The electrode is a metal electrode such as a zinc electrode or a magnesium electrode, or a carbon electrode, and a monitor is connected to the data logger.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a steel pipe pile, which is driven into a hole 2 a excavated in the ground 2. The injection pipe 3 is inserted into the gap G between the steel pipe pile 1 and the wall surface of the hole 2a, and cement milk M is injected.
[0010]
Reference numeral 4 denotes a sensor, which includes a plurality of electrodes 4a (three in this embodiment) made of zinc or the like that exhibit a sufficient contact potential with respect to a strong alkali such as cement milk M, and the plurality of electrodes 4a at appropriate positions. It is composed of a non-conductive rod 4b that is disposed and supported by support, and a cable 4c connected to the plurality of electrodes 4a.
[0011]
The electrode 4a is not limited to a zinc electrode, but is preferably a metal material that exhibits a sufficient contact potential depending on the type of injection solution. The cable 4 c is connected to the data logger 5. 6 is a monitor.
[0012]
For example, as shown in FIG. 2, the sensor 4 is attached to be wound around a bar 4b made of a vinyl chloride hollow pipe, and the cable 4c is wired in the hollow of the bar 4b. It is connected to the.
[0013]
Therefore, when cement milk M is injected into the gap G from the injection pipe 3, the liquid level of the cement milk M rises and reaches the sensor 4 portion.
[0014]
As shown in FIG. 3, when the lowermost electrode 4a is first immersed in the cement milk M as the cement milk M is injected, the intermediate electrode 4a ′ is moved between the cement milk M and the muddy water D. The upper electrode 4a ″ located in the mixed layer MD is further immersed in the muddy water D. Under such circumstances, as shown in FIG. 1, the electrodes 4a and 4a ′ When the potential difference V1 and the potential difference V2 between the electrodes 4a ′ and 4a ″ are measured by the data logger 5, the potential differences V1 and V2 change as shown in FIG.
[0015]
【The invention's effect】
1) Since the electrode serving as the sensor is inexpensive, it can be disposable. Therefore, it is not necessary to consider the durability of the sensor, and the entire system can be provided at a lower cost.
2) In the field work, the labor of collecting the sensor can be saved and the work efficiency can be improved.
3) High-density measurement is possible, and more reliable measurement can be expected.
4) Since a DC voltage is used, the length of the cable can be freely adjusted.
5) There is no fear that the sensor will be lifted by buoyancy, and stable measurement is possible.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an embodiment of the present invention.
FIG. 2 is a structural explanatory view showing an embodiment of a sensor.
FIG. 3 is an explanatory diagram showing a measurement state.
FIG. 4 is a graph showing the relationship between injection elapsed time and potential difference.
FIG. 5 is an explanatory diagram of a conventional measuring method and apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Ground 3 Drilling hole 4 Sensor 4a, 4a ', 4a "electrode 4b Bar material 4c Cable 5 Data logger 6 Monitor D Mud water G Crevice M Cement milk

Claims (6)

A plurality of electrodes are arranged in the space drilled in the ground at appropriate intervals in the vertical direction, and a strong alkaline injection solution such as cement milk is injected into the space, and as the liquid level rises An injection state monitoring method for an injection solution, wherein the injection state is monitored by measuring a change in potential difference between the electrodes. 2. The injection state monitoring method for an injection liquid according to claim 1, wherein the electrode is a metal electrode such as a zinc electrode or a magnesium electrode or a carbon electrode. 3. The method for monitoring an injection state of an injection liquid according to claim 1, wherein the change in the potential difference is monitored by a monitor. In a device for monitoring the injection status of a strong alkaline injection solution such as cement milk injected into the space drilled in the ground , a non-conductive rod and an appropriate interval in the vertical direction along the rod A plurality of electrodes for measuring the change in potential difference as the injection liquid level rises, a sensor comprising a lead wire connected to each electrode, and the other end of each lead wire An infusion state monitoring device for infusate characterized by comprising a data logger. The infusion state monitoring apparatus for infusate according to claim 4, wherein the electrode is a metal electrode such as a zinc electrode or a magnesium electrode or a carbon electrode. 6. The infusion solution injection status monitoring apparatus according to claim 4, wherein a monitor is connected to the data logger.

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