JPH1172323A - Device for measuring ground displacement of earth surface installation type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure displacement even when a pipe body is contracted due to large contraction deformation by providing the pipe body that is laid on the surface of ground where the displacement is to be measured or under the ground near that ground and can be expanded and contracted and a measurement line that is inserted into the pipe body and where one end is fixed to the reference point of the ground and the other is connected to a displacement meter. SOLUTION: A pipe body 2 that can be expanded and contracted is laid on the ground surface of ground 10 where the displacement within the ground surface is to be measured or near that ground at the depth of 0-50 cm, and a measurement line and a projection member 1 including a sheath pipe being provided so that it covers the perimeter of the measurement line are inserted into the pipe body 2, one end is fixed to a stake 6 provided at the reference point of the ground 10, and the other is connected to an instrument 3. Specific tension is applied to the measurement line, the other end is connected to the instrument 3, and a specific tension that is larger than the measurement line is applied to the sheath pipe. A temperature sensor 7 for compensation is provided at an appropriate position in the pipe body 2. The length change of the measurement line of the projection member 1 due to deformation is measured by the displacement meter of the instrument 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a telescopic pipe laid on the ground surface of the ground or in the vicinity of the ground,
A ground-mounted ground displacement measuring device that measures the displacement of the ground by measuring the change in the length of a measurement line with one end fixed to a reference point on the ground and the other end connected to a displacement meter using a displacement meter. It is about.

[0002]

2. Description of the Related Art Conventionally, for example, as a method of measuring in-plane displacement of the ground surface of a ground caused by excavation of a landslide zone or a tunnel, a measurement line such as an invar line is placed at a height of 30 to 50 cm from the ground surface of the ground. It is stretched, one end of the measurement line is fixed to the pile installed at the reference point of the ground, the other end is connected to the displacement meter by applying a predetermined tension, and the change in the length of the measurement line is measured by the displacement meter Thus, a method of measuring the displacement (expansion / contraction) of the ground is known.

[0003]

The method for measuring the displacement of the ground is described as follows.
By stretching the measurement line at a height of 0 cm, the length of the measurement line stretched between a reference point on the ground and a displacement meter installed at a position 20 to 50 m away from the reference point, for example. It measures the change of the ground and measures the displacement of the ground.In this case, since the measurement line is exposed, it is easily affected by wind, snow, other obstacles, etc., and the displacement of the ground is stabilized. There was a problem that it could not be measured.

[0004] The present invention solves the problems of the above-described conventional ground displacement measuring method by laying a pipe into which a measurement line is inserted on the ground surface of the ground or in the ground near the ground. It is an object of the present invention to provide a ground-mounted ground displacement measuring device that can accurately measure the ground displacement even when the pipe body shrinks due to a large shrinkage deformation of the pipe, and has durability.

[0005]

In order to achieve the above object, a ground-mounted ground displacement measuring apparatus according to the present invention comprises an expandable / contractible ground laid on the ground surface of the ground whose displacement is to be measured or near the ground. It is characterized by comprising a pipe and a measurement line inserted into the pipe, one end of which is fixed to a reference point on the ground, and the other end of which is connected to a displacement meter.

[0006] This ground-mounted ground displacement measuring apparatus measures the change in the length of a measurement line that follows the ground displacement with a displacement meter, and thus can immediately and continuously measure the ground displacement. . Then, by laying a telescopic tube on the ground surface of the ground where displacement is to be measured or in the vicinity of the ground, and inserting a measurement line into the tube, wind, snow, and other obstacles Without being affected by the above-mentioned factors, the displacement of the ground can be measured stably.

In this case, a tube made of a synthetic resin having elasticity, such as a bellows tube or a spiral tube, can be used as the tube.

Thus, the installation of the pipe can be remarkably simplified, and the installation cost of the ground displacement measuring device can be reduced.

When a measuring line is directly inserted into a tube, a large tension cannot be applied to a measuring line such as an invar line formed of a very fine line having a diameter of about 0.5 mm (normally, 1 to 4 kgf). For example, as in the case of embankment work or a snowy area, a large vertical load acts on the laid pipe, causing the pipe to bend (bend). This may cause problems such as difficulty in accurately measuring the displacement of the ground and breakage of the measurement line.

In order to address this problem, the circumference of the measurement line can be covered with a spirally wound sheath tube.

As a result, the measurement line does not come into direct contact with the tube, and the spirally wound sheath tube has appropriate rigidity (shape retention force) and elasticity, and the inner surface is smooth, so that the Even if the laid pipe body expands and contracts due to large expansion and contraction deformation, particularly, shrinkage, it is possible to prevent accidents such as loosening of the measurement line and breakage of the measurement line.

[0012] The sheath tube may be constituted by a spirally wound metal sheath tube.

[0013] This makes it possible to easily and inexpensively obtain a sheath tube having appropriate rigidity (shape retaining force) and elasticity and having a smooth inner surface.

Further, it is possible to apply a tension larger than the measurement line to the sheath tube.

[0015] This makes it possible to reliably prevent the sheath tube from being loosened when the tube laid by the large expansion and contraction deformation of the ground expands and contracts, particularly when contraction occurs.

Further, a coating layer made of a synthetic resin can be formed on the outer surface of the sheath tube.

Thus, the measurement line is prevented from being corroded by the groundwater that has entered the pipe body, and the lubricant filled in the sheath pipe is prevented from leaking by the coating layer.
Friction between the sheath tube and the measurement line can be reduced over a long period of time.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ground-mounted ground displacement measuring apparatus according to the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the ground-mounted ground displacement measuring apparatus according to the present invention. This ground-installed ground displacement measuring apparatus is, for example, a ground 1 generated by excavation of a landslide zone or a tunnel.
0 to measure the in-plane displacement of the ground surface.
A telescopic tube 2 laid at a depth of 0 to 50 cm in the ground surface at or near the ground surface 0, and inserted into the tube 2;
One end is fixed to the pile 6 installed at the reference point of the ground 10, and the other end is applied to the displacement gauge 35 installed on the measuring instrument 3 with a predetermined tension and connected to the measurement line 11 and the circumference of the measurement line 11. And the tension member 1 composed of the sheath tube 12 disposed in the above.

In this case, a temperature sensor 7 composed of a thermocouple or the like is provided at an appropriate position in the tubular body 2, and the length of the measurement line 11 measured by the displacement gauge 35 using the value measured by the temperature sensor 7 is used. By correcting the measurement value of the change in temperature, a temperature error included in the measurement value can be eliminated.

As the measurement line 11, an invar line composed of an ultrafine line having a small linear expansion coefficient and a diameter of about 0.5 mm is usually used.

As shown in FIGS. 2 and 3, the sheath tube 12 has an appropriate rigidity (shape holding force) and elasticity as used in a capsule tube of a brake wire of a bicycle, and also has an expandable and contractible shape. The diameter is 2 to 5 mm formed by tightly winding a steel wire or stainless steel wire with a smooth inner surface in a helical shape.
A tubular body in which a coating layer 12b made of a synthetic resin is formed on the outer surface of a tubular body 12a made of metal is used. In this case, it is desirable to fill the sheath tube 12 with a liquid or a paste-like lubricant in order to reduce the friction between the sheath tube 12 and the measurement line 11.

The tube 2 into which the tension member 1 composed of the measurement line 11 and the sheath tube 12 is inserted is expanded and contracted and bent so as to follow the displacement of the ground 10 whose displacement is to be measured.
As shown in, for example, a pipe member 21 made of a synthetic resin such as vinyl chloride or a steel pipe having a length of about 50 cm to 200 cm and a diameter of about 10 to 30 mm, and at least a joint pipe 22 having a diameter larger than that, , One end of which is movably connected. Although not limited, in this embodiment, one end of the pipe member 21 and the joint pipe 22 is
And the other end side is connected by an adhesive 24.

The measuring instrument 3 for connecting the measuring line 11 and the end of the sheath tube 12 is for measuring a change in the length of the measuring line, and a predetermined tension (usually 1 to 4 kgf) is applied to the measuring line 11.
Tension line 31a connected to the measurement line 11 through the untwisting 11a to apply the tension line, the parent and child pulley 32a for winding and unwinding the tension line 31a, and the parent and child pulley 32a via the wire 33a. A weight 34a that urges to rotate in the winding direction of the 31a and a predetermined tension (usually 10 to 20 kgf) greater than the measurement line 11
Tension line 3 connected to the sheath tube 12 to apply
1b, a parent-child pulley 32b for winding and unwinding the tension line 31b, a weight 34b for urging the parent-child pulley 32b to rotate in the winding direction of the tension line 31b via a wire 33b, and a measurement line 11 And a wrap-around displacement meter 35 connected to the measuring wire 11 via a wire 11c and a wire 31c in order to measure a change in the length of the displacement gauge 35, and disposed in a box of the displacement gauge 35 to prevent freezing of the displacement gauge 35 and the like. The film heater 36 is provided.

Next, an example of a method of using the ground-mounted ground displacement measuring apparatus will be described with reference to FIG. This example shows a case in which the time-dependent in-plane displacement of the ground surface of the ground 10 caused by excavation of a landslide zone or a tunnel is measured using the above-described ground displacement measuring device. First, the ground surface of the ground 10 where the in-plane displacement of the ground surface is to be measured or the ground surface near the ground 10
A stretchable tube 2 is laid to a depth of 50 cm, and a tension member 1 including a measurement line 11 and a sheath tube 12 disposed so as to cover around the measurement line 11 is inserted into the tube 2. One end of the extension member 1 is fixed to the pile 6 installed at the reference point of the ground 10, and the other end is connected to the measuring instrument 3. In this case, a predetermined tension (usually 1
４4 kgf), and the other end of the measurement line 11 is connected to the displacement gauge 35 of the measuring device 3.
(About 0 to 20 kgf). In addition, a temperature sensor 7 composed of a thermocouple or the like is provided at an appropriate position in the tube 2.

As a result, the tension member 1 and the pipe 2 of the ground displacement measuring apparatus are deformed following the displacement of the ground 10, and the length of the measurement line 11 of the tension member 1 due to this deformation is changed. Is measured by the displacement meter 35 of the measuring device 3, the displacement of the ground can be measured immediately and continuously. This measured value is displayed on the measuring device 4 and, if necessary, can be transmitted from the measuring device 4 to a monitoring device 5 installed in another place via a wireless or telephone line or the like. Measurements can be monitored simultaneously at a remote location or at multiple locations.
The ground displacement measuring device lays the pipe 2 into which the measuring wire 11 is inserted by laying it on the ground surface of the ground 10 or in the ground near the ground 10 so that the pipe 2 laid by the weight of the snow 20 like a snowy area. Even if a large external force is applied to the body 2 in the vertical direction, the pipe 2 does not bend (bend) that may hinder measurement, so that the influence of snow can be avoided. In addition, by covering the circumference of the measurement line 11 with a tubular body 12a of a sheath tube 12 made of a metal wire having a spiral shape,
The measurement line 11 does not directly contact the tube 2, and
The spirally wound metal sheath tube 12 has appropriate rigidity (shape retention force) and elasticity, and has a smooth inner surface. Even if it occurs, it is possible to prevent an accident such as loosening of the measurement line 11 or breakage of the measurement line. In this case, the measurement line 1
By applying a tension greater than 1, it is possible to reliably prevent the sheath tube 12 from becoming loose when the laid tube 2 expands and contracts, particularly when it contracts due to a large expansion and contraction deformation of the ground 10. . Further, by forming a coating layer 12b made of synthetic resin on the outer surface of the sheath tube 12,
In addition to preventing the measurement line 11 from being corroded by the groundwater that has entered the pipe 2, the leakage of the lubricant filled in the sheath tube 12 is prevented by the coating layer 12b, and the friction between the sheath tube 12 and the measurement line 11 is reduced. It can be reduced over a long period of time. In addition, by correcting the measurement value of the change in the length of the measurement line 11 measured by the displacement meter 35 using the measurement value by the temperature sensor 7, a temperature error included in the measurement value can be eliminated.

In the present embodiment, the measurement line 1
A pipe member 21 having rigidity is inserted into a pipe body 2 into which
The pipe member 21 is connected at least at one end movably by a joint pipe 22 having a larger diameter.
Any pipe having the required elasticity can be used.

FIG. 5 and FIG. 6 show an example in which a tube 2 made of elastic resin such as a bellows tube or a spiral tube is used as a tube 2 into which the measuring line 11 and the like are inserted. Thereby, the laying of the tube 2 can be significantly simplified.

In this case, the synthetic resin tube body 2 such as a bellows tube or a spiral tube has appropriate rigidity (shape retention force) and elasticity, and has a smooth inner surface. Even if the laid pipe 2 expands and contracts, in particular, shrinks, it is possible to prevent the measurement line 1 from being loosened or the measurement line 1 from breaking, so that an accident such as shown in FIG. 6 can be prevented. Thus, the measurement line 1 can be directly inserted into the tube 2.

As described above, the example of measuring the in-plane displacement of the ground surface of the ground caused by excavation of a landslide zone or a tunnel using the ground-mounted ground displacement measuring apparatus of the present invention has been described. The application of the displacement measuring device is not limited to this, for example, the horizontal displacement over time due to the lateral flow of the bottom of the embankment portion of the ground, the ground surface of the embankment portion of the ground or in the ground near this, By laying the ground displacement measuring device, a change in the length of the measurement line 11 of the ground displacement measuring device can be measured immediately and continuously.

[0030]

According to the ground-installed ground displacement measuring apparatus of the present invention, the displacement of the ground is measured by the displacement meter following the displacement of the ground by the displacement meter, so that the displacement of the ground can be immediately continued. Can be measured. In particular, according to this ground-mounted ground displacement measuring device, the measurement of the ground displacement can be performed unattended over a long period of time, and can be monitored simultaneously in a remote place or in a plurality of places. Therefore, it is possible to extremely safely measure the displacement of the ground with the danger of causing a landslide or a landslide. Then, by laying a telescopic tube on the ground surface of the ground where displacement is to be measured or in the vicinity of the ground, and inserting a measurement line into the tube, wind, snow, and other obstacles Without being affected by the above-mentioned factors, the displacement of the ground can be measured stably.

Further, by using an elastic synthetic resin tube such as a bellows tube or a spiral tube for the tube, the laying of the tube can be remarkably simplified, and the installation of the ground displacement measuring device can be achieved. Cost can be reduced.

In addition, by covering the circumference of the measurement line with a spirally wound sheath tube, the measurement line does not come into direct contact with the tube, and the spirally wound sheath tube has an appropriate rigidity (shape). In addition to having holding force) and elasticity, the inner surface is smooth, so the expanded or contracted pipe body due to large expansion and contraction deformation of the ground, especially if the shrinkage occurs, the measurement line will loosen or the measurement line will break etc. Can be prevented beforehand, and the measurement accuracy of the ground displacement and the durability of the ground displacement measuring device can be improved.

Further, by forming the sheath tube with a spirally wound metal sheath tube, a spirally wound sheath tube having appropriate rigidity (shape retaining force) and elasticity and having a smooth inner surface can be easily obtained. And it can be obtained at low cost.

Further, by applying a tension greater than the measurement line to the sheath tube, the sheath tube is slackened when the laid tube body expands and contracts due to a large expansion and contraction deformation of the ground, particularly when the tube shrinks. This can be reliably prevented, and the measurement accuracy of the ground displacement and the durability of the ground displacement measuring device can be further improved.

Further, by forming a coating layer made of a synthetic resin on the outer surface of the sheath tube, it is possible to prevent the measurement line from being corroded by the groundwater that has entered the inside of the tube and to leak the lubricant filled in the sheath tube. Can be prevented by the coating layer, the friction between the sheath tube and the measurement line can be reduced over a long period of time, and the measurement accuracy of the ground displacement and the durability of the ground displacement measuring device can be further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the ground when measuring the in-plane displacement of the ground surface of the ground using the ground-mounted ground displacement measuring apparatus of the present invention.

FIG. 2 is a sectional view of a main part showing an embodiment of a ground-mounted ground displacement measuring apparatus according to the present invention.

FIG. 3 is a cross-sectional view of an extension member (a measurement line and a sheath pipe) of the ground-mounted ground displacement measurement device of the present invention.

FIG. 4 is an explanatory view of a measuring instrument of the ground-based ground displacement measuring device of the present invention.

FIG. 5 is a cross-sectional view of a main part showing another embodiment of the ground-based ground displacement measurement apparatus of the present invention.

FIG. 6 is a cross-sectional view of a main part showing another embodiment of the ground-based ground displacement measuring apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stretching member 11 Measurement line 12 Sheath tube 12a Tubular body 12b Coating layer 2 Tubular body 3 Measuring instrument 35 Displacement gauge 4 Measuring device 5 Monitoring device 6 Pile 7 Temperature sensor 10 Ground

Continuation of the front page (72) Inventor Shin Kisaichi 4-55, Denboku, Konohana-ku, Osaka-shi, Osaka Konoike-gumi Co., Ltd.

Claims (6)

[Claims] 1. A telescopic tube laid under the ground surface or in the vicinity of the ground whose displacement is to be measured, inserted into the tube, one end is fixed to a reference point on the ground, and the other end is A ground-mounted ground displacement measuring device, comprising: a measuring line connected to a displacement meter. 2. The ground-mounted ground displacement measuring apparatus according to claim 1, wherein said tube is made of a synthetic resin tube having elasticity such as a bellows tube or a spiral tube. 3. The ground-mounted ground displacement measuring device according to claim 1, wherein the circumference of the measurement line is covered with a sheath-shaped sheath tube. 4. The ground displacement type ground displacement measuring apparatus according to claim 3, wherein the sheath tube is formed of a metal-made sheath tube having a winding shape. 5. The ground displacement type ground displacement measuring apparatus according to claim 3, wherein a tension greater than a measurement line is applied to the sheath tube. 6. The ground displacement type ground displacement measuring apparatus according to claim 3, wherein a coating layer made of a synthetic resin is formed on an outer surface of the sheath tube.