JP2018197676A - Borehole inclinometer device - Google Patents

Abstract

To provide a borehole inclinometer device that can properly measure an underground inclination change over a long period, as suppressing damage of an inclinometer main body embedded underground.SOLUTION: A borehole inclinometer device 1 for measuring an underground G inclination change, comprises: a plurality of unit pipes 11 that are formed into cylinders each made of a prescribed kind of a metal material, and are embedded underground G in a state with the unit pipe coupled to each other in a length direction; a plurality of inclination sensors that are built in each of the plurality of unit pipes 11, and detect respectively an inclination angle of the corresponding unit pipe 11; a plurality of azimuth sensors that are built in each of the plurality of unit pipes 11, and detect respectively an azimuth of the corresponding unit pipe 11; and a plurality of connection pipes 16 that are formed into cylinders each composed of a material softer than the unit pipe 11 and having a prescribed length, and are fixed to mutually facing end parts of the unit pipes 11 to be coupled in a state where each of the plurality of connection pipes is inserted to the end part thereof.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an in-hole inclinometer for measuring an inclination change in the ground due to a landslide or the like, in which a measuring instrument is fixed in a state of being buried in the ground such as an inclined land.

  Conventionally, as an in-hole inclinometer device for measuring an inclination change in the ground, for example, one disclosed in Patent Document 1 already filed by the present applicant is known. This in-hole inclinometer device is of an installation type in which the measuring instrument is fixed in a state of being buried in the ground. Specifically, in the in-hole inclinometer device, a measuring unit is configured by incorporating a tilt sensor and a direction sensor as a measuring instrument in a cylindrical unit tube having a predetermined length. A plurality of such measurement units are connected in the length direction of the unit tube, thereby forming a long inclinometer body embedded in the ground.

  In each measurement unit, the tilt angle is measured by the tilt sensor, the azimuth is measured by the azimuth sensor, and the measurement data is transmitted to the outside via the transmission cable and the wireless device. The unit tube of each measurement unit is made of stainless steel, and the unit tube has a male screw formed on the outer peripheral surface of one end and a female screw formed on the inner peripheral surface of the other end. . Thereby, in the two measuring units connected to each other, the male screw of one unit tube is screwed into the female screw of the other unit tube, so that these measuring units are connected to each other. Furthermore, a metal cone with a sharp tip is provided at the lowermost part of the inclinometer main body, so that the inclinometer main body can be directly driven into the ground during the embedding work.

  The inclinometer body of the in-hole inclinometer device configured as described above is buried relatively deeply along the vertical direction in the ground such as an inclined land. When the tilt change due to landslide occurs slowly in the ground where the inclinometer body is buried, external force due to the ground acts on the inclinometer body from the side, thereby causing the inclinometer body to gradually deform. Each measuring unit is gradually tilted and displaced from the initial position at the beginning of the burial. Measurement data in each measurement unit is periodically transmitted from such an inclinometer body, and the displacement amount and displacement direction of each measurement unit relative to the initial position are calculated by an arithmetic processing unit such as a personal computer based on the measurement data. Is done. Thereby, it becomes possible to know the displacement amount and displacement direction at each position in the depth direction in the ground, and the transition thereof.

JP 2011-169705 A

  As described above, in the inclinometer body of the conventional in-hole inclinometer device, the unit tube of each measurement unit is made of stainless steel having a relatively high rigidity, and they are directly connected to each other by screwing, A long inclinometer body is constructed. Thereby, the entire outer wall of the inclinometer main body constituted by a plurality of unit tubes has substantially uniform rigidity.

  However, if the inclinometer body embedded in the ground extends over a moving layer that is relatively susceptible to fluctuations on the ground surface side and a stationary layer that is less susceptible to fluctuations deeper than the ground, A relatively large shear force may act on the sliding surface that is the boundary. In this case, the inclinometer body may be damaged near the slip surface. In addition, since the entire outer wall of the inclinometer body has substantially uniform rigidity, in any of the measurement units, damage may occur in the middle in the length direction of the unit tube. Thus, when the unit pipe is broken, underground soil and water easily enter the inside of the unit pipe, and it becomes impossible to appropriately measure the underground inclination fluctuation. Therefore, there is room for improvement in the conventional in-hole inclinometer described above.

  The present invention has been made to solve the above-described problems, and it is possible to appropriately measure the inclination variation in the ground over a long period while suppressing the breakage of the inclinometer body embedded in the ground. An object of the present invention is to provide an in-hole inclinometer device.

  In order to achieve the above object, an invention according to claim 1 is an in-hole inclinometer device for measuring an inclination change in the ground, each of which is made of a predetermined type of metal material and has a predetermined length. A plurality of unit tubes embedded in the ground substantially along the vertical direction in a state of being connected to each other in a longitudinal direction, and being embedded in each of the plurality of unit tubes, A plurality of inclination sensors that detect the inclination angle of the corresponding unit pipe with respect to the reference vertical plane, and built-in each of the plurality of unit pipes, respectively detect the orientation of the corresponding unit pipe with respect to a predetermined reference vertical line A plurality of azimuth sensors, detection data transmitting means for transmitting detection data of the detected inclination angle and azimuth for each unit tube to the outside, and each comprising a softer material than the metal constituting the unit tube Is formed in a cylindrical shape having a monitor predetermined length, characterized in that it comprises a plurality of connecting tubes which are fixed respectively inserted state opposite ends of unit pipes to be connected.

  According to this configuration, a plurality of unit tubes each formed of a predetermined type of metal material and having a predetermined length are connected to each other in the longitudinal direction, and in a substantially vertical direction. Along the ground, it is buried in the ground where the inclination variation should be measured. Each unit tube incorporates an inclination sensor that detects an inclination angle of the unit tube with respect to a predetermined reference vertical plane, and an orientation sensor that detects the direction of the unit tube with respect to a predetermined reference vertical line. Further, the plurality of unit tubes are connected via cylindrical connecting tubes respectively inserted into opposite ends of the unit tubes to be connected, and each connecting tube is more than the metal constituting the unit tube. Consists of soft material. In this way, a plurality of unit tubes incorporating the tilt sensor and the orientation sensor are connected via the connecting tube, so that a long inclinometer body is configured and buried in the ground substantially along the vertical direction. Is done.

  In the ground in which the inclinometer body is buried, when tilt fluctuations due to landslide occur slowly, external force due to the ground acts on the inclinometer body from the side, thereby gradually deforming the inclinometer body. As a result, each unit pipe gradually inclines and displaces from the initial position at the time of embedding. In this case, the connecting pipes that connect the unit pipes are made of a softer material than the unit pipes, so that the connecting pipes are easily bent, and as a result, the unit pipes themselves are not damaged due to the deformation of the inclinometer body. Can be suppressed over. The detection data transmission means transmits the detection data detected by the inclination sensor and the azimuth sensor in each unit tube to the outside. Based on these detection data, the displacement amount and displacement direction of each unit tube with respect to the initial position can be calculated by an arithmetic processing unit such as a personal computer. As described above, according to the present invention, it is possible to appropriately measure the inclination variation in the ground over a long period while suppressing the breakage of the inclinometer main body embedded in the ground.

  According to a second aspect of the present invention, in the in-hole inclinometer device according to the first aspect, screw holes are respectively formed at opposite ends of the unit pipes to be connected. A plurality of long holes are formed, which respectively match the holes and extend in a predetermined length in the length direction, and slidably engage with the screws attached to the screw holes.

  According to this configuration, the screw holes are respectively formed at the end portions of the unit pipes to be connected, while the connecting pipes inserted into the end portions of the both unit pipes match the screw holes and each screw hole. A plurality of long holes that are slidably engaged with the screws attached to each other are formed. As a result, the two unit tubes connected via the connecting tube are connected in a state where they can approach or separate from each other in the length direction. As a result, when the inclinometer main body is deformed as described above due to underground inclination fluctuation, that is, when the connecting pipe is bent or the unit pipe is inclined / displaced, the degree of freedom increases, and the underground inclination fluctuation is flexible. By responding to the above, breakage of the inclinometer body can be more effectively suppressed.

  The invention according to claim 3 is the in-hole inclinometer device according to claim 1 or 2, wherein the unit tube is made of nonmagnetic stainless steel, and the connecting tube is a metal material mainly composed of aluminum. It is characterized by comprising.

  According to this configuration, since the unit tube is made of non-magnetic stainless steel, even when, for example, an azimuth sensor that uses geomagnetism is used, the azimuth is appropriately adjusted without being affected by the unit tube. Can be detected. Further, since the connecting pipe is made of a metal material mainly composed of aluminum, the connecting pipe is softer and less rigid than the unit pipe made of stainless steel. It can be easily realized.

It is a figure which shows the state which installed the in-hole inclinometer apparatus of this invention in the inclined ground. (A) is a figure which shows partially the inside of an inclinometer main body, (b) is a figure which decomposes | disassembles and shows the connection part of measurement units. It is a figure which shows the in-hole clinometer apparatus inclined / displaced with the inclination fluctuation | variation in the ground. It is a figure which shows an example of transition of the measurement result about the underground inclination fluctuation | variation.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a state where an in-hole inclinometer device according to an embodiment of the present invention is installed on an inclined ground. The inclinometer 1 in the hole is of an installation type in which an inclinometer body 2 as a measuring instrument is fixed in a state where it is buried in the ground in order to measure an underground inclination variation due to a landslide or the like.

  As shown in FIG. 1, the in-hole inclinometer device 1 is embedded in the underground G in a state of extending substantially along the vertical direction, and the inclinometer body 2 for measuring the inclination variation, and the inclinometer body A data storage / transmitter 3 that stores data measured by 2 and wirelessly transmits to the outside, a solar panel 4 that supplies power to the inclinometer main body 2 and the data storage / transmitter 3, and the like. The data storage / transmitter 3 and the solar panel 4 are attached to the upper part of the support column 5 fixed in a state where the lower half is buried in the ground G.

  Further, as shown in FIG. 1, the inclined ground where the in-hole inclinometer device 1 is installed is inclined in a predetermined direction (the right direction in FIG. 1). The moving layer GU is more likely to fluctuate, and the lower layer is a non-moving layer GD that hardly fluctuates. Therefore, the slip surface S is formed between the upper moving layer GU and the lower non-moving layer GD.

  The inclinometer main body 2 extends in the vertical direction by connecting a plurality of (seven in FIG. 1) measuring units 6 to each other, and is configured to be long. FIG. 2A partially shows the inside of the inclinometer body 2. As shown in the figure, each measurement unit 6 includes a metal unit tube 11, a measurement unit 12 that is built in the unit tube 11 and measures an inclination angle and a direction, which will be described later, and an electrical connection to the measurement unit 12. And a transmission cable 13 (13a, 13b) for transmitting an electrical signal.

  The unit tube 11 is made of nonmagnetic stainless steel (for example, SUS304), and is formed in an elongated cylindrical shape having a predetermined diameter (for example, outer diameter: 2.5 cm) and a length (for example, 100 cm). Further, as shown in FIG. 2B, two screw holes 11a and 11a that are opposed to each other in the horizontal direction are formed at predetermined positions of the upper end portion and the lower end portion of the unit tube 11, respectively.

  As shown in FIG. 2A, the measurement unit 12 includes a circuit board 12a, an inclination sensor 12b, an orientation sensor 12c, a temperature sensor 12d, and the like incorporated on the circuit board 12a. The circuit board 12 a is formed in an elongated plate shape, and the upper and lower ends thereof are screwed to the unit tube 11 in a state where the circuit substrate 12 a is disposed at the center in the length direction of the unit tube 11. In addition, the inclination sensor 12b detects the inclination angle of the corresponding unit tube 11 with respect to a predetermined reference vertical plane (for example, a vertical plane orthogonal to the inclination direction of the inclined ground at the beginning of embedding), while the direction sensor 12c An orientation in which the corresponding unit tube 11 is displaced with respect to a reference vertical line (for example, a vertical line passing through the lowest measurement unit 6 at the beginning of embedding) is detected. Furthermore, the temperature sensor 12d detects the temperature in the unit tube 11.

  Male and female connectors 14a and 14b are provided at the distal ends of the upper and lower transmission cables 13a and 13b extending from the circuit board 12a, respectively. These connectors 14a and 14b are connected to the connectors 14b and 14a of the other upper and lower measuring units 6 in a waterproof state.

  In the unit pipe 11, caps 15 and 15 are provided on both sides of the circuit board 12a in the length direction so as to be fitted with caps 15 and 15 for preventing water and the like from entering the measuring unit 12 side. . Each cap 15 is made of a predetermined type of waterproof material, and is formed in a two-stage columnar shape having a small diameter on the measurement unit 12 side. The transmission cable 13 penetrates each cap 15 in a watertight state through the center.

  As shown in FIG. 2, the plurality of measuring units 6 configured as described above have unit tubes 11 connected to each other via a connecting tube 16. The connecting pipe 16 is made of a metal material (for example, aluminum alloy) mainly composed of aluminum, and has a cylindrical shape having an outer diameter (for example, 2 cm) slightly smaller than the inner diameter of the unit pipe 11 and a predetermined length (for example, 20 cm). Is formed. Further, as shown in FIG. 2B, both end portions (upper end portion and lower end portion) of the connecting pipe 16 are opposed to each other in the horizontal direction, and are elongated holes extending a predetermined length in the length direction of the connecting pipe 16. 16a and 16a are formed.

  In the measurement units 6 and 6 that are connected to each other, the connecting pipe 16 is inserted into the ends of the unit pipes 11 and 11, and the long holes 16 a are screwed into the screw holes 11 a of the unit pipe 11. 17 is slidably engaged with the shaft portion. Thereby, each measurement unit 6 is connected with the measurement unit 6 connected via the connection pipe 16 in the state which can approach or leave | separate.

  As shown in FIG. 1, a cone 18 having a sharp lower end is provided at the lower end of the lowest measurement unit 6. The cone 18 is made of metal, the lower half is formed in a conical shape, the upper half is formed in a cylindrical shape, and the upper half is inserted into the lower end of the measuring unit 6 and screwed. Has been.

  The inclinometer main body 2 configured as described above can be embedded, for example, by directly driving into the underground G without performing boring. Specifically, first, the cone 18 is attached to the end of the measurement unit 6, and then the measurement unit 6 is driven from above with a hammer or the like with the cone 17 applied to the ground surface of the ground G. Specifically, the measurement unit 6 is driven in until a predetermined length (for example, 20 cm) is projected from the ground surface. Thereafter, the lower half portion of the connecting pipe 16 is inserted into the unit pipe 11 of the measurement unit 6 that has been driven in from above, and the respective long holes 16a of the connecting pipe 16 are matched with the corresponding screw holes 11a of the unit pipe 11. Then, the screw 17 is screwed into each screw hole 11a.

  Next, the connector 14a of the transmission cable 13a of the measurement unit 6 (hereinafter referred to as “lower measurement unit” as appropriate) 6 driven into the ground G and another measurement unit (hereinafter referred to as “upper measurement unit” as appropriate) to be connected. The connector 14b of the transmission cable 13b of 6 is connected. Thereafter, the upper half of the connecting pipe 16 attached to the lower measuring unit 6 is inserted into the lower end of the upper measuring unit 6, and each screw hole 11 a of the upper measuring unit 6 is inserted into the corresponding long hole of the connecting pipe 16. The screw 17 is screwed into each screw hole 11a in a state where it is matched with 16a.

  In this case, both measurement units 6 and 6 are connected in a state where the lower end of the unit tube 11 of the upper measurement unit 6 is in contact with the upper end of the unit tube 11 of the lower measurement unit 6. Thereafter, the connected upper measurement unit 6 is driven from above until the upper part protrudes from the ground surface by a predetermined length (for example, 20 cm).

  As described above, by repeating the driving from the upper side of the measurement unit 6 and the connection of the measurement unit 6 via the connection pipe 16, the plurality of measurement units 6, that is, the inclinometer main body 2 is substantially in the vertical direction. Along the underground G.

  In the in-hole inclinometer device 1 configured as described above and having the inclinometer main body 2 embedded in the ground G, the measurement unit 6 (unit tube 11) of the measurement unit 6 is measured by the inclination sensor 12b and the orientation sensor 12c. The inclination angle and direction are periodically detected, and the temperature in the measurement unit 6 at that time is detected by the temperature sensor 12d. Note that the inclination sensor 12b and the azimuth sensor 12c are easily affected by the temperature at the time of detection, and therefore the inclination angle and azimuth detected by the inclination sensor 12b and the azimuth sensor 12c depend on the temperature detected by the temperature sensor 12d. Therefore, it is corrected to an appropriate value.

  Then, the corrected inclination angle and direction of each measurement unit 6 are transmitted to the data storage / transmitter 3 on the ground via the transmission cable 13 and stored therein, and also externally (for example, a remote receiving device) Etc.).

  FIG. 3 shows an in-hole inclinometer device 1 (solid line) that is inclined and displaced in accordance with the inclination variation of the underground G, and the two-point difference line shows the initial state of embedding. As shown in the figure, in the underground G, when the moving layer GU moves greatly with respect to the non-moving layer GD, the inclination variation due to landslide occurs. When such a tilt variation occurs slowly, in the inclinometer body 2, external force by the moving layer GU is laterally applied to a plurality of (four in FIG. 3) measuring units 6 embedded in the moving layer GU. By acting from (left side of FIG. 3), the inclinometer body 2 is gradually deformed, whereby each measuring unit 6 is gradually inclined and displaced from the initial position at the time of embedding.

  As described above, in the inclinometer main body 2, the connecting pipe 16 that connects the unit pipes 11 of the measuring unit 6 is made of an aluminum alloy that is softer than the unit pipe 11 made of stainless steel. For this reason, in the inclinometer main body 2 to which an external force acts from the side as described above, the connecting pipe 16 is bent, and in particular, the connecting pipe 16 in the vicinity of the slip surface S of the underground G is bent by a relatively large amount. 6 unit pipes 11 themselves can be prevented from being damaged.

  FIG. 4 shows an example of the transition of the measurement result of the inclination variation in the underground G. In addition, the inclinometer main body 2 of this example is obtained by connecting five measuring units 6 via four connecting pipes 16. FIG. 4 shows the results from August 1, 2015 to November 1, 2016. This shows the transition of the measurement results. FIG. 4 shows the accumulated displacement amount in the slope direction of the five measurement units 6 when it is assumed that the lower end portion of the inclinometer body 2 is stationary. From the measurement result shown in the figure, in the underground G in which the inclinometer body 2 is embedded, the displacement amount in the inclination direction at a predetermined depth from the ground surface can be easily known.

  As described above, according to the present embodiment, the plurality of measurement units 6 constituting the inclinometer body 2 are connected via the connection pipe 16 made of a softer aluminum alloy than the unit pipes 11. Therefore, when an external force acts on the inclinometer body 2 from the side due to the inclination variation of the underground G, the connecting pipe 16 is easily bent, and as a result, the unit tube 11 itself is damaged along with the deformation of the inclinometer body 2. Can be suppressed over a long period of time. In addition, detection data of the tilt angle and direction detected by each measurement unit 6 is received by the reception device, and each measurement unit 6 (unit tube 11) relative to the initial position is received by an arithmetic processing device such as a personal computer based on the detection data. ) And the displacement direction are calculated. As described above, according to the present embodiment, it is possible to appropriately measure the inclination variation of the underground G over a long period while suppressing the breakage of the inclinometer main body 2 embedded in the underground G.

  In addition, each connecting pipe 16 is formed with a long hole 16a slidably engaged with a shaft portion of a screw 17 screwed to the unit pipe 11 of the measuring unit 6. The two measurement units 6 that are connected are connected in a state in which they can approach or move away from each other in the length direction. As a result, when the inclinometer body 2 is deformed due to the inclination variation of the underground G, that is, when the connecting pipe 16 is bent or the measuring unit 6 is inclined / displaced, the degree of freedom increases, and the inclination of the underground G By responding flexibly to fluctuations, it is possible to more effectively suppress breakage of the inclinometer body 2.

  In addition, this invention can be implemented in various aspects, without being limited to the said embodiment described. For example, in the embodiment, the unit pipe 11 of the measuring unit 6 is made of stainless steel, while the connecting pipe 16 is made of an aluminum alloy. However, the present invention is not limited to this, and the connecting pipe 16 is made of stainless steel. As long as the material is softer than steel, it can be made of other metals or other materials (for example, synthetic resins) other than metals. Further, in the embodiment, the inclinometer body 2 is configured by the seven measurement units 6, but the present invention is not limited to this, and the inclinometer body is connected by connecting 6 or less or 8 or more measurement units 6. Of course, it is also possible to configure 2.

  The detailed configuration of the in-hole inclinometer device 1, the inclinometer body 2, the measurement unit 6, and the connecting pipe 16 shown in the embodiment are merely examples, and may be appropriately changed within the scope of the present invention. be able to.

1 Inclinometer device for in-hole 2 Inclinometer body 3 Data storage / transmitter (detection data transmission means)
6 Measuring unit 11 Unit pipe 12 Measuring section 12b Inclination sensor 12c Direction sensor 13 Transmission cable 16 Connecting pipe 16a Long hole 17 of connecting pipe Screw G Underground GU Moving layer GD Non-moving layer S Sliding surface

Claims (3)

An in-hole inclinometer device for measuring inclination fluctuation in the ground,
A plurality of unit tubes each of which is made of a predetermined type of metal material and is formed in a cylindrical shape having a predetermined length and is embedded in the ground substantially along the vertical direction in a state of being connected to each other in the length direction. When,
A plurality of inclination sensors built in each of the plurality of unit tubes and detecting the inclination angles of the corresponding unit tubes with respect to a predetermined reference vertical plane;
A plurality of azimuth sensors built in each of the plurality of unit tubes, each for detecting a direction of a corresponding unit tube with respect to a predetermined reference vertical line;
Detection data transmission means for transmitting detection data of the detected inclination angle and direction for each unit tube to the outside;
Each is made of a material softer than the metal constituting the unit tube and is formed into a cylindrical shape having a predetermined length, and is fixed in a state where it is inserted into opposite ends of the unit tubes to be connected. A plurality of connected pipes,
In-hole inclinometer device characterized by comprising. Screw holes are formed in the opposing ends of the unit tubes to be connected,
The connecting pipe is formed with a plurality of elongated holes that respectively match the threaded holes and extend a predetermined length in the longitudinal direction, and slidably engage with the screws attached to the threaded holes. The in-hole inclinometer device according to claim 1. The unit tube is made of nonmagnetic stainless steel,
The in-hole inclinometer device according to claim 1 or 2, wherein the connecting pipe is made of a metal material mainly composed of aluminum.

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