JPH0812255B2 - Groundwater flow point, flow direction, flow velocity measurement method and its measuring instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a method for measuring the position of the flow of groundwater existing in the ground and one or both of its flow direction and flow velocity, and the method. The present invention relates to a measuring instrument used for implementation of

<Prior art> As is well known, groundwater is important in water resources, and in construction work, the problems of measuring the flow direction and velocity of groundwater have been emphasized in terms of stopping water and drainage. .

By the way, it has been practiced to measure groundwater flow locations, flow directions, and flow velocities in boreholes drilled in the ground, and the measurement methods include so-called groundwater logging, temperature logging, and borehole. The use of television is known.

However, in the above method, the electrolytic substance and warm water have to be put into the boring hole, but at this time, it becomes very difficult to uniformly mix the electrolytic substance, and the measurement cannot be performed simultaneously in a wide area. At the same time, it was difficult to obtain detailed results for the above-mentioned measured object.

<< Problems to be Solved by the Invention >> The present invention has been studied in view of the problems of the above-mentioned conventional means. In claim (1), a plurality of heaters are provided without injecting any substance into groundwater. , A special measuring instrument equipped with a plurality of required temperature measuring elements in the vicinity not only in the horizontal direction but also in the vertical direction is embedded in a boring hole in the ground, and each of these heaters is electrically heated. The temperature distribution of the temperature measuring elements in the vertical and horizontal directions at the time of measurement was measured with the passage of time, and based on each temperature distribution temporal change graph obtained by this, where is the location of groundwater flow? , And the flow direction, flow velocity, or both can be measured, which enables simple and quick measurement without causing pollution, and also enables highly accurate and wide-range simultaneous measurement. The purpose is to try.

According to claim (2), for the measuring instrument used for carrying out the method according to claim (1), a plurality of heaters that can be separately energized, and a plurality of temperature measuring elements provided near them Not only is this provided on the base body, but the temperature measuring element is provided next to it in the horizontal direction, and in the longitudinal direction of the long base body,
By arranging a required number of adjacent water sources, it is possible to detect not only the direction and flow velocity of groundwater, but also the depth position of groundwater flowing in the boring hole. However, it is intended to make it possible to obtain the measurement method simply and quickly, and to reduce the labor of the measurement method, shorten the accuracy time, and improve the accuracy.

According to claim (3), in addition to the configuration of the measuring device according to claim (2), a packer that is inflatable by sending and releasing air, liquid, etc. is attached to the upper and lower parts thereof, thereby providing the measuring device. When it is installed in the boring hole, it is stopped by the expanded packer, the groundwater at the measurement point does not flow in the vertical direction, and it is tried to improve the reliability of the measurement result. That is the purpose.

<< Means for Solving the Problem >> In order to achieve the above-mentioned object, the present application provides a boring hole in the ground having groundwater, according to claim (1),
In the boring hole, a plurality of required heaters which are arranged in a horizontal direction and are vertically separated from each other, and a plurality of required temperature measurement elements which are provided in the vicinity of the heaters and which are arranged in a vertical direction and are separated from each other are formed on the substrate. The measuring instrument provided is embedded, and each of the plurality of heaters is energized separately, so that when heating, the temperature measurement results with respect to the passage of time by the temperature measuring elements arranged in the longitudinal direction are Directional temperature distribution over time graph, the circumferential temperature distribution over time graph is obtained from the temperature measurement results for the passage of time by the temperature measuring elements arranged in the circumferential direction, and from the longitudinal temperature distribution over time graph, Provides a groundwater flow point, flow direction, and flow velocity measurement method, which is characterized by detecting one or both of the flow direction and flow velocity from the circumferential temperature distribution temporal change graph. According to claim (2), a plurality of required heaters are arranged in a longitudinal direction on a long base body while being laterally separated from each other. The temperature measuring element is provided, and the heater, the respective heater lead wires connected to the temperature measuring element, and the temperature measuring element lead wire are derived from the base body. The flower, the flow direction, and the flow velocity measuring device according to claim 3, and further, in claim (3), the packer in which a gas or a liquid can be sent and released above and below the base body with respect to the configuration of claim (2). Is attached to the contents.

<< Operation >> According to the measurement method of claim (1), when each heater is energized and heated, the temperature of groundwater around the heater changes with time. If you measure the temperature of each temperature measuring element over time, you can obtain a graph of longitudinal temperature distribution over time, and if you know where in this graph there is a low temperature, The flow depth of groundwater can be determined from the known position where it is provided.

Further, if the temperature change of each temperature measuring element arranged in the lateral direction when each heater is electrically heated is measured, a circumferential temperature distribution temporal graph is obtained,
From the form of this graph, the groundwater flow direction and flow velocity can be obtained.

Next, according to the measuring device of claim (2), a plurality of temperature measuring elements arranged in the circumferential direction and a plurality of temperature measuring elements arranged in the vertical direction are installed in the vicinity of the heater provided on the substrate. Therefore, when the method according to the above-mentioned claim (1) is carried out, the circumferential temperature distribution time-dependent change graph and the vertical direction temperature distribution time-dependent change graph can be measured with high accuracy, and moreover, human power is required for the measurement. The purpose can be achieved without using it.

Further, according to claim (2), after the measuring device is inserted into the boring hole, air or the like is sent to the upper and lower packers to inflate it and press it against the inner wall of the boring hole. Since the upper and lower parts of the measuring instrument can be stopped with water, groundwater does not flow from top to bottom at the measurement point, and as a result, the measured value of groundwater flow can be more accurate. Can be

<< Example >> Prior to explaining the measuring method of claim (1), the measuring device according to claim (2) and claim (3) will be explained with reference to FIGS. 1 to 3.

The measuring instrument according to claim (2) uses an elongated base 1 made of an electrically insulating material or the like having a low thermoconductivity. For this, it is preferable to adopt a substrate having a diameter of 20 to 60 mm and a length of 50 cm or more, A plurality of required heaters 2, 2, ... Are provided on the base body 1 so as to be separated in the horizontal direction during use, and are arranged in parallel in the vertical direction (longitudinal direction). The temperature measuring elements 3, 3 are located near the heaters 2, 2
Also, in the exposed state, and by separating them in the longitudinal direction of the substrate, only a required plurality of them are arranged, and in fact, the relevant element 3,
3 It is better to use a high resolution 1/100 to 1/1000 ° C.

Here, the substrate 1 in the illustrated example has a cylindrical shape, but other shapes can be used, and the heaters 2, 2, ... Are all linear.

In addition, the heaters 2, 2 are individually connected to both terminals 2a,
Heater lead wires 4a, 4b extend from 2b into the base body 1. Further, these heater lead wires 4a, 4b are focused on a cord 5 drawn from one end surface side of the base body 1 and externally. Therefore, the heaters 2, 2 ... Can be electrically conducted for each heater and can be separately heated.

Further, the temperature measuring element lead wires 6 connected to the temperature measuring elements 3, 3 are also focused and led out to the cord 5 through the inside of the base body 1, and the cord 5 is, as explained later with reference to FIG. It will be connected to the controller 8 connected to the temperature measuring device 7.

Next, in the measuring device according to claim (2), as also shown in FIGS. 1 to 3, gas and liquid are fed to and discharged from the upper and lower parts of the base body 1, respectively. Packers 9a and 9b are provided so that they can be inflated freely.

In the illustrated example, the upper packer 9a is attached to the outer periphery of the cord 5 extending from the base 1, and the lower packer 9b is connected to the lower end of the base 1.

Further, in the cord 5, there is a supply pipe 10a for air or the like.
Is provided and is communicated with the packer 9a, and the lower end of the packer 9a and the lower packer 9b are connected by the supply pipe 10b that is inserted through the base body 1 as shown in FIG. Therefore, the upper and lower packers 9a and 9b are inflated by supplying air or the like from the supply pipe 10a.

Therefore, in order to carry out the measuring method according to claim (1) using the above-mentioned measuring device, first, preparation as shown in FIG. 4 is made.

That is, the boring hole B is bored in the ground A, and the measuring instrument according to claim (1) or (2) is lowered into the boring hole B. (H in the figure indicates the water level of the groundwater W.) And, in the measuring instrument of claim (2), by operating the compressor C connected to the supply pipe 10a, the packer 9a, Sending air to 9b to make it full,
This fixes the measuring instrument in that position,
Groundwater in the measurement range in the hole, which is between the upper and lower packers 9a, 9b, is to prevent the groundwater from leaking down from the range, and of course, when using the measuring device of claim (1), The suspended state will be maintained at the desired position.

When such preparation is completed, the heater 2 of the desired substrate 1 is energized to heat it and heat the entire temperature measuring elements 2, 3
The temperature at each point is measured with time by using, and after this measurement is performed for a certain period of time, the power to the heater 2 is turned off, and the temperature measurement by the temperature measuring elements 3, 3 is continued. Then, the measurement ends when the measured temperature at each point reaches a constant value.

By the side temperature as described above, the relationship of temperature with respect to time in the circumferential direction and the longitudinal direction will be obtained, but with the circumferential direction, the temperature measuring element 3 over the entire circumference for each progress,
3 is a graph showing a temporal change in temperature distribution in the circumferential direction, which shows the side temperature results according to 3 ..., Examples of which are shown in FIGS. 5 (a) to 5 (e).

In FIG. 5, black dots indicate heating points by the heater 2. The heater 2 is heated to raise the water temperature in the boring hole B, and the water temperature measurement result at that time is
The temperature distribution obtained by measuring the water temperature change with time after the heating of the heater is stopped is shown. From the circumferential temperature distribution time change graph, for example, as shown in FIG. In addition, it is possible to know that the flow rate is upward, and if the flow of groundwater is fast, the temperature drop of the heating point with time is large, so that the flow velocity can also be measured.

Further, as a longitudinal temperature distribution temporal change graph obtained by the temperature measuring elements arranged in the depth direction, a result as shown in FIG. 6 can be obtained.

This shows that there is a difference in the degree of temperature rise and fall with time depending on the depth, and in the figure, the case where the heater 2 is electrically heated to raise the temperature of groundwater is shown. At the location where the groundwater W is flowing, the temperature rise is small, and thus the depth at which the groundwater W is flowing can be known.

<< Effects of the Invention >> According to the measurement method of claim (1) of the present application, the heater is also vertically long, and a plurality of temperature measurement elements are provided separately in the vertical direction,
Moreover, a plurality of heaters and temperature measuring elements are arranged in the horizontal direction as well, so that the vertical temperature distribution temporal change graph and the circumferential temperature distribution temporal change graph can be detected respectively, so that no electrolytic substance or hot water is You can easily and quickly know the location of groundwater, and its flow direction, flow velocity, or both, without the need to put it in and stir it, without pollution, and simultaneously perform measurements at a wide range of locations. It is also possible to do.

Since the measuring device of claim (2) is also configured as described above and the heater and the temperature measuring element are appropriately arranged, it is convenient to carry out the method of claim (1).

Further, by using the measuring device according to claim (3), the installation of the packer completely cuts off the groundwater at the set location from the influence of other causes. Therefore, the groundwater flow location, the flow direction, and the flow velocity can be measured. The result can be highly reliable.

[Brief description of drawings]

FIG. 1 is a schematic front view in which a part of a measuring instrument according to claim (2) used for carrying out the measuring method of the present application is cut away,
The figure shows an enlarged horizontal front view showing the main part of the measuring instrument, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 shows an embodiment of the measuring method using the measuring instrument. Fig. 5 (a), (b), (c), (d), and (e) of the vertical section of the on-site panel are graphs of changes in the circumferential temperature distribution over time showing examples of actual measurements of the same method. It is an example of a vertical direction temperature distribution temporal change graph. 1 ... Substrate 2 ... Heater 3 ... Temperature measuring element 4a, 4b ... Head lead wire 6 ... Temperature measuring element lead wire 9a, 9b ... Packer A ... Ground B ... Boring hole W ... Groundwater

Claims (3)

[Claims] Claims: 1. A boring hole is bored in the ground having groundwater, and a plurality of required heaters vertically spaced apart from each other in the lateral direction are provided in the boring hole, and in the vicinity of the heaters. A plurality of required temperature measuring elements which are vertically separated from each other are embedded in a measuring device provided on the base body, and the plurality of heaters are separately energized, and the heaters are separately arranged in the vertical direction during heating. From the temperature measurement results with respect to the passage of time by each of the temperature measuring elements, a longitudinal temperature distribution temporal change graph is shown, and from the temperature measurement results with respect to the passage of time by the temperature measuring elements arranged in the circumferential direction, the circumferential temperature is shown. Obtaining a distribution temporal change graph, and measuring the flow location of the groundwater from the longitudinal temperature distribution temporal change graph, and measuring one or both of its flow direction and flow velocity from the circumferential temperature distribution temporal change graph. Flow point of ground water, characterized, flow direction, flow velocity measurement method. 2. A plurality of required temperature measuring elements are provided on a long base in a vertically long manner while being separated from each other in the horizontal direction, and in the vicinity of each of the heaters, a plurality of required temperature measuring elements are provided apart from each other in the vertical direction. Arranged, these heaters, each different heater lead wire connected to the temperature measuring element, the temperature measuring element lead wire, the flow point of the groundwater, characterized in that it is derived from the base body, Flow direction, flow measuring instrument. 3. A plurality of required heaters are arranged in a longitudinal direction on a long base body while being laterally spaced apart from each other. These heaters, the respective heater lead wires connected to the temperature measurement element, and the respective temperature measurement element lead wires are led out from the above-mentioned base body, and gas or liquid is sent above and below the base body. A groundwater flow point, flow direction, and flow velocity measuring device, which is equipped with a removable packer.