JP4703773B1 - Ground displacement measuring device - Google Patents

Abstract

An object of the present invention is to provide a ground displacement measuring device capable of easily and inexpensively measuring a borehole inclination and a groundwater level and obtaining highly reliable data on the relationship between the rise of the groundwater level and ground deformation. .
An inclination sensor arrangement portion 2 in which an inclination sensor capable of measuring an inclination angle of the casing pipe 1 is arranged in a casing pipe 1 inserted into a boring hole 4 excavated in the ground, and enters the casing pipe 1 A water level meter 13 for measuring the groundwater level and / or a groundwater circulation part 3 for inserting a groundwater logging sonde are individually formed in the axial direction of the casing pipe 1. A total of 13 and / or groundwater logging sondes are inserted and arranged in a replaceable manner, and a plurality of flow holes 33 are provided in the wall surface of the casing pipe 1 to allow the groundwater to flow in and out between the ground and the groundwater flow part 3. And arranged in the axial direction of the casing pipe 1.
[Selection] Figure 1

Description

The present invention relates to an apparatus for measuring the displacement of the ground due to a landslide or the like.

JP 2002-318114 A

Conventionally, when measuring ground displacement such as landslides, observations using borehole inclinometers and changes in groundwater levels have been performed for the purpose of grasping the slip surface position and measuring the amount of displacement of the slip surface. ing. As the in-hole inclinometer, a movable inclinometer or an embedded inclinometer has been generally used. In other words, the mobile inclinometer has a probe with a built-in tilt sensor inserted into the bottom of the borehole in a casing pipe inserted and placed in the borehole, and the tilt angle of the probe is set at a fixed distance while pulling up the probe. Is detected by an inclination sensor, and the overall deflection of the guide pipe can be measured. In addition, the embedded type inclinometer has a case with a built-in tilt sensor fixedly placed in the borehole at a fixed distance, and when the ground changes, the tilt sensor can detect the tilt of each point in the borehole. It is what.

An inclinometer as shown in Patent Document 1 is known as an embedded inclinometer as described above. In the inclinometer of Patent Document 1, a plurality of cases with built-in inclination sensors are fixedly arranged at fixed distances inside the casing pipe, and the inclination of the casing pipe after the ground fluctuation is generated is described above. It is intended to be detected by an inclination sensor. In addition, the method of measuring changes in groundwater level is greatly affected by the position and amount of groundwater flowing into the ground. In addition to this, it is necessary to measure the groundwater level, and conventionally, both methods have been used to measure ground displacement.

However, in the case of the prior art as described above, in order to measure the groundwater level, the borehole for measuring the groundwater level and the borehole for placing the inclinometer are formed at completely different positions. It had been. For this reason, it is necessary to separately form a borehole for measuring the groundwater level in addition to the borehole for placing the inclinometer, and a large number of boreholes must be formed. It requires a lot of labor and expense. In addition, as described above, conventionally, the measurement of the inclination of the borehole and the measurement of the groundwater level are performed at different positions, so it has been difficult to obtain highly reliable data on ground deformation.

Therefore, the present invention is intended to solve the above-described problems, and can measure the inclination of the borehole and the groundwater level easily and inexpensively, and has the same relationship between the rise of the groundwater level and ground deformation. It is intended to obtain a ground displacement measuring device capable of obtaining highly reliable data by measuring with a borehole.

  In order to solve the above-mentioned problems, the present invention inserts a casing pipe into a bored hole excavated in the ground, and arranges an inclination sensor capable of measuring the inclination angle of the casing pipe in the casing pipe. An inclination sensor is formed by separately forming an arrangement portion and a water level meter for measuring the level of groundwater infiltrated into the casing pipe and / or a groundwater circulation portion for inserting a groundwater logging sonde in the axial direction of the casing pipe. In the arrangement part, the inclination sensor is arranged in the casing pipe, and in the groundwater circulation part, the water level gauge and / or groundwater logging sonde is inserted and arranged, and the ground pipe and the groundwater circulation part are inserted in the casing pipe. A plurality of through holes that allow groundwater to flow in and out between them.

By configuring the present invention as described above, it is possible to measure the in-hole inclination and the groundwater level in the same hole. Therefore, when ground change occurs, the groundwater level and the slope in the borehole are measured at the same position, and the reason for the ground change can be clarified comprehensively and accurately together with the groundwater level and the slope of the ground. It is possible to obtain highly reliable data.

Moreover, it becomes possible to perform a groundwater logging by inserting and arranging a groundwater logging sonde in the groundwater circulation part of the casing pipe. Therefore, it is not necessary to separately provide a borehole for groundwater logging, so that groundwater logging can be performed easily and at low cost. In addition, since groundwater logging and borehole inclination can be measured at the same position when ground deformation occurs, the relationship between the groundwater flow position and ground fluctuation position can be accurately grasped.

Further, in the present invention, either a water level meter or a groundwater logging sonde can be inserted into the groundwater circulation section to individually perform water level observation and groundwater logging, and a state in which a water level gauge is installed in the groundwater circulation section in advance. Thus, it is also possible to insert a groundwater logging sonde into the groundwater circulation section and place it in the groundwater circulation section to measure the water level gauge and perform the groundwater logging in parallel. However, when water level measurement and groundwater logging are performed in parallel as described above, the groundwater level in the groundwater distribution section is artificially set for groundwater logging so as not to hinder groundwater measurement. It is necessary to carry out groundwater logging using only the groundwater previously retained in the groundwater circulation section without increasing it.

Moreover, the inside of the inclination sensor arrangement | positioning part which has arrange | positioned the inclination sensor may be previously filled with a potting material. Thereby, since the inclination sensor in the inclination sensor arrangement part is in a potted state, it becomes difficult for moisture to come into contact with the inclination sensor, and the inclination sensor can be kept in a good state in the inclination sensor arrangement part.

The casing pipe may be formed by integrally forming a cylindrical outer wall and a cylindrical inner wall disposed inside the outer wall via a partition wall. As described above, the casing pipe is divided into a plurality of parts in the axial direction by integrally forming the outer wall, the inner wall, and the partition wall of the casing pipe. It becomes possible to easily form a groundwater circulation part.

As described above, since the present invention is such that the inclination sensor arrangement part and the groundwater circulation part are formed in one casing pipe, the inclination sensor is arranged in the inclination sensor arrangement part and the water level meter is arranged in the groundwater circulation part. By doing so, the in-hole inclination and the groundwater level can be measured at the same position. Therefore, when ground change occurs, the groundwater level and the slope in the borehole are measured at the same position, and the reason for the ground change can be clarified comprehensively and accurately together with the groundwater level and the slope of the ground. It is possible to obtain highly reliable data.

Also, in addition to observing the groundwater level by inserting a water level meter into the groundwater circulation part as described above, by inserting and arranging a groundwater logging sonde instead of the water level gauge in the groundwater circulation part,
It becomes possible to perform groundwater logging. Therefore, it is not necessary to provide an additional borehole for groundwater logging, and groundwater logging can be performed easily and at low cost. It becomes easy to detect the position and the like. In addition, when ground deformation occurs, the groundwater fluidized bed and borehole slope can be measured at the same position, so it is possible to accurately grasp the relationship between the groundwater flow position and the ground fluctuation position. it can.

Sectional drawing which shows Example 1 of this invention. The partial expanded sectional view of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. BB sectional drawing of FIG. 1 is a conceptual diagram illustrating a communication system of a tilt sensor in Embodiment 1. FIG. FIG. 6 is a partial cross-sectional view showing a second embodiment. The CC sectional view taken on the line of FIG. The DD sectional view taken on the line of FIG. The EE line of FIG. 7 and the FF line expanded view of FIG. Sectional drawing which shows Example 3. FIG. The elements on larger scale of FIG. The GG sectional view taken on the line of FIG. Sectional drawing of Example 4. FIG. Sectional drawing of Example 5. FIG.

A first embodiment of the present invention will be described with reference to FIGS. 1 to 5. As shown in FIG. 1, (1) is a casing pipe formed of a resin material. (2) and the groundwater circulation part (3) are separately arranged in parallel in the axial direction, and the casing pipe (1) is inserted and arranged in a boring hole (4) excavated in the ground. Hereinafter, the first embodiment will be described in detail. First, when the inclination sensor arrangement portion (2) is formed in the casing pipe (1), a rectangular opening elongated in the axial direction of the casing pipe (1). An L-shaped bracket (10) having a tilt sensor (8) fixedly disposed on the inner surface of a closing plate (6) capable of closing the opening (5) as shown in FIG. ) And the communication infrastructure (7) are fixedly arranged.

The tilt sensor (8) of the present embodiment is a biaxial acceleration sensor, which is formed in a 5 mm square plate shape. This tilt sensor (8) has a structure in which the polysilicon structure is floated from the wafer surface by a polysilicon spring, and the deflection of the polysilicon structure is attached to an independently fixed electrode and a movable part. Measurement is made with a differential capacitor composed of a center electrode, and acceleration can be detected.

Furthermore, the cover member (11) covering the communication board (7) and the inclination sensor (8) fixedly arranged on the inner surface of the closing plate (6) as described above is fixedly arranged on the closing plate (6). The communication board (7), the inclination sensor (8) and the cover member (11) are fixedly disposed on the closing plate (6), as shown in FIGS. 1) It is fixedly arranged in the opening (5) of the casing pipe (1) so as to be located inward, and the opening (5) is closed.

By fixing the closing plate (6) to the opening (5) as described above, the closing plate (6) forms a part of the casing pipe (1). As shown in FIGS. 7) The tilt sensor (8) and the cover member (11) are located on the inner peripheral surface of the casing pipe (1), and when the casing pipe (1) is inserted into the bore hole (4). The tilt sensor (8) is positioned in the horizontal direction. And the part enclosed by the said cover member (11) and the internal peripheral surface of a casing pipe (1) is made into the inclination sensor arrangement | positioning part (2) in a present Example.

The tilt sensor placement portion (2) is filled with silicone rubber as a potting material, and the tilt sensor (8) in the tilt sensor placement portion (2) is potted in advance. By potting the tilt sensor (8) in this way, it becomes difficult for moisture to contact the tilt sensor (8). Therefore, it becomes possible to keep the inclination sensor (8) in a good state in the inclination sensor arrangement part (2).

As shown in FIGS. 1 and 5, one end of a communication cable (16) is connected to the upper side and the lower side of the communication board (7) arranged in the inclination sensor arrangement part (2). As shown in FIGS. 1 and 2, the other end of each communication cable (16) is inserted into the space between the casing pipe (1) and the boring hole (4) through the closing plate (6). Each is connected to a communication board (7) disposed on the next casing pipe (1) via a closing plate (6) of the casing pipe (1). Then, as shown in FIG. 5, the other end of the communication cable (16) above the communication base (7) arranged in the uppermost casing pipe (1) is connected to the data logger (17) arranged on the ground. ing.

Moreover, the part other than the said inclination sensor arrangement | positioning part (2) in a casing pipe (1) is made into the groundwater distribution part (3) in a present Example. And as shown in FIGS. 1-4, several through-holes (33) are penetrated and formed in the wall surface of the casing pipe (1) which comprises this groundwater distribution part (3). Therefore, groundwater can flow out and in between the ground and the groundwater circulation section (3) through the circulation hole (33).

As described above, since the inclination sensor arrangement part (2) and the groundwater circulation part (3) are arranged in one casing pipe (1), the inclination sensor (8) is arranged in the inclination sensor arrangement part (2). And a water level meter (13) in the groundwater circulation section (3) can measure the in-hole inclination and the groundwater level in the same borehole (4). Therefore, if ground change occurs, the groundwater level and borehole slope at the same position can be measured, so the reason for the ground change is clarified comprehensively and accurately together with the groundwater level and ground slope. Therefore, highly reliable data can be obtained.

A filter (19) is wound around the outer periphery of the casing pipe (1) formed as described above as shown in FIG. By attaching the filter (19) to the casing pipe (1) in this way, the circulation hole (33) is covered with the filter (19), so that solid matter such as soil and stone in the ground is groundwater. At the same time, it can be prevented from flowing into the casing pipe (1) through the flow hole (33). Therefore, since only the groundwater can flow into the groundwater circulation part (3) through the circulation hole (33), the water level in the groundwater circulation part (3) can be observed smoothly.

Further, as shown in FIG. 2, a fitting projection (38) and a fitting recess (40) are formed at the upper and lower ends of the casing pipe (1) to which the filter (19) is mounted as described above. The fitting projection (38) and the fitting recess (40) are respectively fitted into the fitting recess (40) and the fitting projection (38) of the adjacent casing pipe (1), and are shown in FIG. In this way, a plurality of casing pipes (1) are connected and fixed in the axial direction.

  And the float (14) of the float type water level gauge (13) is inserted and arranged in the groundwater circulation part (3). This float type water level gauge (13) is connected to a float (14) floating in ground water at one end of a wire (15) and a weight (not shown) via a pulley (not shown) at the other end. It is a thing. The vertical movement of the float (14) accompanying the vertical movement of the groundwater level can be recorded as a graph on a recording sheet of a drum (not shown) connected to the pulley. The groundwater level in () can be observed.

In the structure configured as described above, for example, when a landslide occurs on the ground where the ground displacement measuring device is disposed, the casing pipe (1) in the borehole (4) is inclined by the landslide. And the inclination sensor (8) which arrange | positioned the inclination of this casing pipe (1) in the casing pipe (1) measures data regularly, and X / Y-axis acceleration is measured, Furthermore, this X / Y-axis acceleration is measured. Is converted into a tilt angle. As shown in FIG. 5, the inclination angle detected by each inclination sensor (8) as described above is transmitted to the data logger (17) via the communication infrastructure (7) and the communication cable (16).

The tilt angle data detected by the data logger (17) is accumulated in a memory built in the data logger (17), and the accumulated data is finally transmitted to the data collection personal computer (18) for storage. Is done. For example, when groundwater flows into the groundwater circulation part (3) from the circulation hole (33) of the casing pipe (1) when this landslide occurs, the groundwater level in the groundwater circulation part (3) rises. As the groundwater level rises, the float (14) rises, and the rise of the float (14) is recorded on the recording paper of the drum, so that the rise in the groundwater level can be observed.

In the above description, the water level gauge (13) is inserted and arranged in the groundwater circulation section (3) to explain the observation of the groundwater level in the groundwater circulation section (3), but the groundwater circulation section replaces the water level gauge (13). It is also possible to perform groundwater logging as required by inserting and arranging a groundwater logging sonde (34) in (3). This groundwater logging will be described below. First, an electrolyte solution having a constant concentration is stored in advance in the groundwater circulation section (3). Then, when groundwater flows into the groundwater circulation part (3) from the ground through the circulation hole (33), the groundwater electrolyte concentration in the groundwater circulation part (3) is caused by the inflow of the groundwater. Will be diluted at a certain position of the groundwater circulation part (3).

Therefore, among the plurality of flow holes (33) formed in the axial direction of the casing pipe (1), groundwater flows from the flow holes (33) at any depth. Immediately after inserting the groundwater logging sonde (34) into the groundwater distribution section (3) and moving it up and down in the groundwater distribution section (3), the groundwater distribution section (3) at multiple depths of groundwater Measure the electrical resistance of groundwater.

The data measured by the groundwater logging sonde (34) as described above is transmitted to the groundwater logging measuring instrument (36) connected to the groundwater logging sonde (34) via the cable (35). In the groundwater logging measuring instrument (36), the electrical resistance data of the groundwater at each depth is accumulated. And the dilution state of the electrolyte concentration in each depth is calculated from this data, and the position where the degree of dilution is large is determined as the groundwater flow position.

As described above, by inserting the groundwater logging sonde (34) into the groundwater circulation section (3), the groundwater logging sonde (34) and the tilt sensor (8) disposed in the tilt sensor placement section (2) By this, in-hole inclination and groundwater logging can be measured in the same borehole (4). Therefore, the relationship between the groundwater flow position and the ground fluctuation position can be accurately grasped, and the data related to ground fluctuation can be made more accurate.

After the groundwater logging, the electrolyte solution in the groundwater circulation part (3) is naturally discharged from the bottom of the circulation hole (33) and the casing pipe (1). Therefore, after discharging the electrolyte solution, the water level gauge (13) is inserted and placed in the groundwater circulation section (3) again in place of the groundwater logging sonde (34), thereby observing the water level in the groundwater circulation section (3). You can resume.

In the first embodiment, the inclination sensor (8) fixedly arranged on the inner peripheral surface of the casing pipe (1) is covered with the cover member (11), and the inner peripheral surface of the cover member (11) and the casing pipe (1). The part surrounded by is an inclination sensor arrangement part (2), but in this embodiment 2, the casing pipe
An inner wall (20) and a plurality of partition walls (21) are integrally formed inside the outer wall (29) of (1).
(20) The portion surrounded by the partition wall (21) and the inner peripheral surface of the outer wall (29) is the tilt sensor placement portion.
In addition to (2), the inside wall (20) is the groundwater distribution section (3). Thus, in this embodiment, the outer wall (29), the inner wall (20), and the partition wall (21) of the casing pipe (1) are integrally formed, so that the inclination sensor arrangement part (2) and the groundwater circulation part (3 ) Can be easily formed.

The second embodiment will be described below with reference to FIGS. 6 to 9. In the casing pipe (1), as shown in FIG. 7, the inner wall of the outer wall (29) of the casing pipe (1) is spaced from the inner peripheral surface by a predetermined distance. A cylindrical inner wall (20) is provided on the side. And by arranging six partition walls (21) in the radial direction between the inner wall (20) and the outer wall (29), the outer peripheral surface of the inner wall (20) and the inner peripheral surface of the outer wall (29) The space to be formed is divided into six in the circumferential direction, and six dividing chambers (22) are provided.

  In the present embodiment, the tilt sensor arrangement portion (2) is provided in one of the six divided chambers (22). The tilt sensor arrangement portion (2) in the present embodiment will be described. First, the opening (5) is formed in the casing pipe (1) as in the first embodiment. Then, a bracket (10) and a communication base (7) in which an inclination sensor (8) is fixedly disposed on the outer peripheral surface of the inner wall (20) exposed at the opening (5) as shown in FIG. ) Is fixedly arranged in the axial direction. Then, above and below the communication base (7) and the inclination sensor (8) fixedly arranged on the inner wall (20) as described above, the outer peripheral surface of the inner wall (20) and the outer wall (29) are arranged as shown in FIG. Between the inner peripheral surface, a pair of partition plates (23) are fixedly arranged in a direction perpendicular to the axial direction of the casing pipe (1).

The portion surrounded by the pair of partition plates (23) and the outer peripheral surface of the inner wall (20) is filled with potting material, and the opening (5) of the casing pipe (1) is further closed. It is closed with a plate (6). The closing plate (6) constitutes a part of the outer wall (29) of the casing pipe (1). As a result, as shown in FIGS. 6 and 7, the portion surrounded by the outer peripheral surface of the inner wall (20), the pair of partition walls (21), the inner peripheral surface of the outer wall (29), and the pair of partition plates (23), The inclination sensor arrangement part (2) of the present embodiment is formed, and the inclination sensor arrangement part (2) is filled with a potting material.

Moreover, in the said Example 1, although parts other than the inclination sensor arrangement | positioning part (2) in a casing pipe (1) are made into the groundwater distribution part (3), in this Example, the inner peripheral side of the said inner wall (20) Is the groundwater distribution department (3).

  In the first embodiment, as shown in FIG. 1, the communication cable (16) connected to the inclination sensor (8) is inserted into the gap between the boring hole (4) and the casing pipe (1). In the embodiment, as shown in FIG. 7, the divided chamber (22) adjacent to the inclination sensor arrangement part (2) is a communication cable arrangement part (24), and the communication cable arrangement part (24) is connected to the inclination sensor (8). The connected communication cable (16) is inserted and arranged.

  That is, as shown in FIG. 9, one end side of the communication cable (16) is connected to the inclination sensor (8) and the other end side of the communication cable (16) is connected to the inclination sensor arrangement portion (2) and the communication cable arrangement portion. It is inserted and arranged in the communication cable arrangement part (24) through the insertion hole (25) formed in the partition wall (21) between (24). Then, the next inclination sensor arrangement part (24) is inserted into the next inclination sensor arrangement part (24) through an insertion hole (25) formed in the partition wall (21) between the communication cable arrangement part (24) and the next inclination sensor arrangement part (2). 2) It is connected to the tilt sensor (8). In addition, in order to maintain the airtightness in the inclination sensor arrangement part (2) and prevent the communication cable (16) from being damaged by contact with the edge of the layer through hole, the insertion hole (25) and the communication cable (16) is filled with a soft elastic sealing material (26) to seal the layer through-holes.

As described above, the communication cable (16) is inserted into the insertion hole (25) through the sealing material (26) and connected to the communication cable placement portion (24), whereby the communication cable (16) is tensioned upward. Even in the case where the force is applied, the force due to the tension is first transmitted to the insertion hole (25). Therefore, the tension is relaxed at the connection portion between the communication cable (16) and the inclination sensor (8), and the connection portion between the inclination sensor (8) and the communication cable (16) becomes difficult to be damaged. Can be used stably.

Further, as shown in FIGS. 6 to 8, the inner wall (20) and the outer wall (29) of the divided chamber (22) other than the inclination sensor arrangement portion (2) are provided with a flow hole (33) as a shaft of the casing pipe (1). A plurality of through holes are formed in the direction. By forming the flow hole (33) so as to penetrate in this way, groundwater can flow out and in between the ground and the groundwater flow part (3) through the flow hole (33). As in the first embodiment, the outer periphery of the casing pipe (1) formed as described above is covered with the filter (19), and the fitting protrusions formed at the upper and lower ends of each casing pipe (1) ( 38) and fitting recesses (40) are fitted into fitting recesses (40) and fitting projections (38) formed in the other casing pipe (1), respectively, thereby providing a plurality of casing pipes (1). Connected.

Moreover, in the said Example 1, although the float (14) of the float type water level meter (13) is inserted and arranged in the groundwater circulation part (3), in this Example 2, it is a hydraulic type in the groundwater circulation part (3). The probe (28) of the water level gauge (27) is inserted and arranged. That is, as shown in FIG. 6, the probe (28) of the water level gauge (27) is inserted and arranged near the bottom of the casing pipe (1), and the cable (30) connected to the upper end of the probe (28) is connected to the groundwater. It is inserted to the outside through the circulation section (3) and connected to a data logger (31) for a water level meter (27) installed on the ground.

Further, a water guide hole (32) through which ground water can be introduced is provided at the lower end side of the probe (28), and a pressure receiving portion is provided in the probe (28) above the water guide hole (32). (Not shown). The groundwater level in the groundwater circulation section (3) can be measured by sensing the water pressure of the groundwater flowing into the probe (28) from the water conveyance hole (32) with the pressure receiving section.

Thus, since the inclination sensor arrangement part (2) and the groundwater circulation part (3) are arranged in one casing pipe (1), the inclination sensor (2) arranged in the inclination sensor arrangement part (2) ( 8) and the water level gauge (27) arranged in the groundwater circulation part (3) can measure the in-hole inclination and the groundwater level in the same borehole (4). Therefore, if ground change occurs, the groundwater level and borehole slope at the same position can be measured, so the reason for the ground change is clarified comprehensively and accurately together with the groundwater level and ground slope. Therefore, highly reliable data can be obtained.

  Similarly to the first embodiment, in this embodiment, a groundwater logging sonde (34) is inserted and placed in the groundwater circulation section (3) in place of the water level gauge (27). That is what the layer can do. Therefore, it is possible to measure the in-hole inclination and groundwater logging in the same borehole (4) by the groundwater logging sonde (34) and the inclination sensor (8) arranged in the inclination sensor arrangement part (2). Therefore, it is possible to accurately grasp the relationship between the groundwater flow position and the ground fluctuation position.

  Moreover, although the above demonstrated the case where either the water level meter (27) or the groundwater logging sonde (34) was inserted and arranged in the groundwater circulation part (3), the water level gauge ( It is also possible to perform water level observation and groundwater logging in parallel by inserting and placing a groundwater logging sonde (34) in the groundwater circulation section (3) with the 27) inserted. The case where the groundwater observation and the groundwater logging are performed in parallel will be described. First, the water pressure type water level gauge (27) is inserted and disposed in the groundwater circulation part (3) in advance as described above.

Immediately after the electrolyte is poured into the groundwater already retained in the groundwater circulation section (3) to obtain a predetermined electrolyte concentration, a groundwater logging sonde (34) is inserted into the groundwater circulation section (3). Place and perform groundwater logging. At the time of this groundwater logging, since only the already accumulated groundwater is used, there is no possibility that the groundwater level will fluctuate greatly. Therefore, even when groundwater logging is performed simultaneously with water level observation, there is almost no risk of hindering continuous water level observation, and groundwater logging and water level observation can be performed smoothly in parallel.

Further, in the second embodiment, as shown in FIG. 7, a space is provided over the entire circumference between the outer wall (29) and the inner wall (20) of the casing pipe (1). As shown in FIG. 1, a cylindrical inner wall (20) is integrally formed on the inner peripheral side of the outer wall (29) of the casing pipe (1). Thus, by integrally forming the outer wall (29) and the inner wall (20) of the casing pipe (1), the flow hole (33) is formed in the portion where the outer wall (29) and the inner wall (20) are integrated. When forming the flow hole, it is not necessary to form the flow hole (33) in each of the outer wall (29) and the inner wall (20), so that the trouble of forming the flow hole (33) can be reduced.

The third embodiment will be described with reference to FIGS. 10 to 12. By arranging four partition walls (21) in the radial direction between the outer peripheral surface of the inner wall (20) and the inner peripheral surface of the outer wall (29). As shown in FIG. 12, the space formed by the outer peripheral surface of the inner wall (20) and the inner peripheral surface of the outer wall (29) is divided into five in the circumferential direction, and five divided chambers (22) are provided. And the inclination sensor arrangement | positioning part (2) is provided in one division chamber (22) of the division chambers (22) divided into five as mentioned above. The tilt sensor arrangement portion (2) will be described below. First, a rectangular opening (5) elongated in the axial direction is formed in the casing pipe (1).

  A bracket (10) having a communication base (7) and a tilt sensor (8) fixedly arranged on the outer peripheral surface of the inner wall (20) exposed from the opening (5) is a casing pipe as shown in FIGS. It is fixedly arranged in the axial direction of (1). The communication base (7) and the inclination sensor (8) fixedly disposed on the inner wall (20) as described above are located above and below the space between the outer peripheral surface of the inner wall (20) and the inner peripheral surface of the outer wall (29). In addition, a pair of partition plates (23) are fixedly arranged in a direction perpendicular to the axial direction of the casing pipe (1).

The portion surrounded by the pair of partition plates (23) and the outer peripheral surface of the inner wall (20) is filled with a potting material. In this state, the opening (5) of the casing pipe (1) is closed. It is closed with a plate (6). The closing plate (6) constitutes a part of the casing pipe (1). Accordingly, as shown in FIGS. 11 and 12, the portion surrounded by the outer peripheral surface of the inner wall (20), the pair of partition walls (21), the inner peripheral surface of the outer wall (29), and the pair of partition plates (23) is formed. In addition to the inclination sensor arrangement portion (2) in the present embodiment, the inclination sensor (8) is positioned in the horizontal direction by inserting and arranging the casing pipe (1) in the boring hole (4).

Further, since the potting material is filled in the inclination sensor arrangement portion (2), the inclination sensor (8) in the inclination sensor arrangement portion (2) is thereby potted. Therefore, it becomes difficult for moisture to come into contact with the inclination sensor (8), and the inclination sensor (8) can be kept in a good state in the inclination sensor arrangement portion (2). Moreover, the inner peripheral side of the inner wall (20) is used as the groundwater circulation part (3) in the present embodiment. Further, as shown in FIG. 12, the division chamber (22) adjacent to the inclination sensor arrangement portion (2) is a communication cable arrangement portion (24), and the communication cable arrangement portion (24) is the same as in the second embodiment. In addition, as shown in FIG.
The communication cable (16) connected to (8) is inserted and arranged.

  Further, the casing pipe (1) includes a portion where the outer wall (29) and the inner wall (20) are integrated as shown in FIG. 12, and a dividing chamber (22) other than the inclination sensor arrangement portion (2). A flow hole (33) is formed through the outer wall (29) and the inner wall (20) from the outer peripheral surface of the casing pipe (1) to the inner peripheral surface of the inner wall (20). As shown in FIGS. 10 and 11, a plurality of locations are formed in the axial direction of the casing pipe (1).

By forming the circulation hole (33) as described above, the groundwater can flow out and in between the ground and the groundwater circulation part (3) through the circulation hole (33). As in the first embodiment, the outer periphery of the casing pipe (1) formed as described above is covered with the filter (19), and the fitting protrusions formed at the upper and lower ends of each casing pipe (1) ( 38) and fitting recesses (40) are fitted into fitting recesses (40) and fitting projections (38) formed in the other casing pipe (1), respectively, thereby providing a plurality of casing pipes (1). Connected.

  And like the said Example 1, 2, the water level in a groundwater distribution part (3) can be observed by inserting and arrange | positioning a water level meter (13) in the groundwater distribution part (3) formed as mentioned above. In addition, as shown in FIG. 10, groundwater logging can be performed as necessary by inserting and arranging a groundwater logging sonde (34) in place of the water level gauge (13). Therefore, since groundwater level and inclination in the borehole can be measured at the same position when ground deformation occurs, the reason for the ground deformation is clarified comprehensively and accurately together with the groundwater level and ground slope. In addition, it is possible to measure the slope of the borehole and groundwater logging in the same borehole (4), so it is possible to accurately grasp the relationship between the groundwater flow position and the ground fluctuation position. It becomes possible to obtain highly reliable data.

  In the first to third embodiments, the casing pipe (1) having a circular cross section is used. However, in the fourth embodiment, the casing pipe (1) having a square cross section is used as shown in FIG. By using the casing pipe (1) having a square section in this way, the closing plate (6) can be formed into a flat plate shape as shown in FIG. Therefore, in Examples 1 to 3, the closing plate (6) is connected and fixed to the casing pipe (1) with an adhesive, but in this embodiment, the closing plate (6) is bolted to the casing pipe (1). Since it can be fastened, it is possible to secure the fixing of the closing plate (6) to the casing pipe (1).

An inner wall (20) having a square cross section is provided in the outer wall (29) of the casing pipe (1) at a constant interval from the inner peripheral surface of the outer wall (29). And by arranging a partition wall (21) in a space formed between the inner wall (20) and the casing pipe (1), this space is divided into four to provide four divided chambers (22). Yes. One of the divided chambers (22) is used as the inclination sensor arrangement part (2) in the present embodiment, and the inside wall (20) is used as the groundwater circulation part (3).

The tilt sensor placement portion (2) is filled with a potting material, and the tilt sensor (8) is potted. Further, as shown in FIG. 13, the divided chambers (22) located on both sides of the inclination sensor arrangement part (2) are communication cable arrangement parts (24), and the communication cables (16) are inserted and arranged respectively. Further, the arrangement method of the inclination sensor (8) in the inclination sensor arrangement portion (2) is the same as in the second embodiment. The outer wall (29) and the inner wall (20) constituting the divided chamber (22) other than the inclination sensor arrangement part (2) are each formed with a through hole (33).

As in the first embodiment, the outer periphery of the casing pipe (1) formed as described above is covered with the filter (19), and the fitting protrusions formed at the upper and lower ends of each casing pipe (1) ( 38) and fitting recesses (40) are fitted into fitting recesses (40) and fitting projections (38) formed in the other casing pipe (1), respectively, thereby providing a plurality of casing pipes (1). Connected. A float type water level gauge (13) float (14) is inserted in the groundwater circulation section (3). When performing groundwater logging, the float (14) is taken out and groundwater is removed. A logging probe (34) can be inserted and placed.

  Further, in the first to third embodiments, the casing pipe (1) having a circular cross section and in the fourth embodiment using a square cross section is used. A circular casing pipe (1) is used. Thus, by using the casing pipe (1) having a semicircular cross section, when the boring hole (4) having a circular cross section is formed, one side of the borehole (4) in the axial direction is provided with the A casing pipe (1) having a semicircular cross section can be inserted and arranged, and another measuring instrument or the like can be inserted and arranged in a semicircular space formed on the other side. Therefore, the space in the boring hole (4) can be used efficiently.

Then, a groundwater circulation part (3) having a circular cross section is formed on one side of the casing pipe (1), and a fan-shaped inclination sensor arrangement part (2) and a communication cable arrangement part having a substantially rectangular cross section are formed on the other side. (24) is formed. The tilt sensor placement portion (2) is filled with a potting material, and the tilt sensor (8) is potted. As in the second embodiment, the inclination sensor (8) is arranged in the inclination sensor arrangement part (2), and the communication cable (16) is inserted and arranged in the communication cable arrangement part (24).

Further, as shown in FIG. 14, a through hole (33) is formed through the wall surface of the casing pipe (1) on the side of the groundwater circulation section (3) formed as described above. As in the first embodiment, the outer periphery of the casing pipe (1) formed as described above is covered with the filter (19), and the fitting protrusions formed at the upper and lower ends of each casing pipe (1) ( 38) and fitting recesses (40) are fitted into fitting recesses (40) and fitting projections (38) formed in the other casing pipe (1), respectively, thereby providing a plurality of casing pipes (1). Connected. A float type water level gauge (13) float (14) is inserted in the groundwater circulation section (3). When performing groundwater logging, the float (14) is taken out and groundwater is removed. A logging probe (34) can be inserted and placed.

DESCRIPTION OF SYMBOLS 1 Casing pipe 2 Inclination sensor arrangement part 3 Groundwater distribution part 4 Boring hole 8 Inclination sensor 13, 27 Water level gauge 20 Inner wall 21 Bulkhead 29 Outer wall 33 Distribution hole 34 Groundwater logging sonde

Claims (3)

In the casing pipe inserted and arranged in the borehole drilled in the ground, the inclination sensor arrangement part in which the inclination sensor that can measure the inclination angle of this casing pipe is arranged, and the water level that measures the level of groundwater that has entered the casing pipe A groundwater circulation section for inserting a gauge and / or a groundwater logging sonde is individually formed in the axial direction of the casing pipe, and the water level gauge and / or the groundwater logging sonde is inserted in the groundwater circulation section. In addition, the ground displacement is characterized in that a plurality of flow holes for allowing the groundwater to flow in and out between the ground and the groundwater circulation part are arranged in the axial direction of the casing pipe on the wall surface of the casing pipe. measuring device.   2. The ground displacement measuring device according to claim 1, wherein the tilt sensor placement section pots the tilt sensor by filling a potting material with the tilt sensor disposed therein.   The casing pipe is formed by integrally forming a cylindrical outer wall and a cylindrical inner wall disposed inside the outer wall via a partition wall provided at a distance between the inner wall and the outer wall. 1 Ground displacement measuring device.

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