JP2562173B2 - Simple ground displacement meter with variable voltage divider - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a simple horizontal displacement meter using a variable voltage divider, and more particularly to a simple horizontal displacement meter using a variable voltage divider for automatic civil engineering measurement.

2. Description of the Related Art When constructing a structure on the ground, there is a demand for computerized construction that measures the subsidence of the ground and the horizontal displacement of the ground surface to predict the behavior of the ground and proceed with the construction.

Conventional methods for measuring the horizontal displacement of the ground surface include a manual measurement method that uses a displacement pile, a manual measurement method that inserts an insertion-type inclinometer into a guide pipe to obtain lateral deformation, and two methods on the ground surface. There is a ground surface extensometer method in which an amber wire is placed between the piles and the recording drum rotates when relative displacement occurs and the pen is automatically filled in.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the horizontal displacement measurement of the ground surface, the manual measurement method such as the displacement pile method and the insertion type inclinometer method has a problem that not only requires a skilled worker but also a construction obstacle in some cases. The automatic pen writing at the measuring position in the surface extensometer method has a problem that an error is likely to occur at a construction site. Therefore, an object of the present invention is to provide a simple horizontal surface displacement meter which can prevent construction failures and eliminate the need for a skilled operator, and has a minimum number of parts.

Means for Solving the Problems Referring to FIG. 1, a simple horizontal displacement meter 40 using a variable voltage divider of the present invention is a frame with a cover 13 that can be placed on the ground surface 5.
7a (see FIGS. 3 and 5), a wire protection device 12 integrated with the cover 13, a shaft 8 pivotally supported by the frame 7a, the cover
A wire 3, which is engaged with and fixed to the peripheral surface of the shaft 8 from the outside of the shaft 13 through the wire protection device 12 from one rotation direction,
A constant force spring 9 having one end held by the frame 7a and the other end engaged with and fixed to the peripheral surface of the shaft 8 in the opposite rotation direction, and the frame having a rotating portion coupled to the shaft 8.
7a is provided with a fixed variable voltage divider 10, and the variable voltage divider 10 generates an output corresponding to a horizontal displacement of the ground surface between the point where the other end of the wire 3 is fixed and the shaft 8. Is used.

Effect In the simple horizontal displacement meter 40 of the present invention, without using a member such as a communication pipe or a rod that easily disturbs the construction, it is possible to install a wire or a constant force spring so as not to hinder the construction,
Furthermore, since the output of the variable voltage divider is an electric signal, continuous automatic recording can be easily performed. Therefore, the object of the present invention is to prevent the construction failure and to eliminate the need for a skilled operator, and to provide a simple ground surface horizontal displacement meter having a minimum number of parts.

Embodiment In FIGS. 1 and 3 to 5, the constant load spring 9 is a shaft 8.
The wire 3 is kept under tension by a constant load via. That is, when the space L between the two points A and B of the ground expands or contracts, the constant load spring 9 draws or retracts the wire 3 by the rotation of the shaft 8 to bring the wire 3 into a tension state under a constant load. Hold. Since the wire 3 that is kept under constant load does not expand or contract,
The amount of wire 3 drawn out or drawn in indicates the amount of expansion or contraction of the space L between the two points A and B of the ground, that is, the amount of horizontal displacement of the ground. The variable voltage divider 10 connected to the constant load spring 9 can generate an output according to the displacement of the constant load spring 9 such as rotation, and thus, with this output, the ground level between the two points A and B is leveled. The displacement can be represented.

FIGS. 2 to 5 show an example of the simple land subsidence meter 6 designed to be suitable for soft ground by applying the principle of the simple horizontal displacement meter 40 according to the present invention.

As a conventional automatic measurement method for measuring ground subsidence, the water level is kept constant at the position of the fixed point, a vinyl chloride communication pipe is installed up to the position of the measurement point, and the amount of ground subsidence is detected by a differential transformer. There is a way. As a method that does not use a communication pipe, there is also a method in which the fixed point of the underground ground layer is taken, the rod is raised from this point, and the subsidence amount is obtained by a potentiometer-type displacement meter attached to the rod on the ground surface. Furthermore, as a method that does not use a fixed point, there is also a method in which the strain at several points in the depth direction is measured by a strain gauge and the subsidence amount is detected from the measured value by trapezoidal integration.

As a conventional measurement method for measuring ground subsidence by layer,
There are a method using a sinking plate and a method inserting a detector into a tube having a fixed point in the support layer. As the detector type, the position of different layers is indicated by the change in the thickness of the tube, and the position of the change in thickness is detected by the claws provided on the detector, and the steel disk is installed at the position of different layers. There is one that detects the position of the steel disk by the change in magnetic flux in the detector.

However, these conventional ground subsidence measuring methods have drawbacks in that construction failures are likely to occur and that skilled labor is required. That is, in ground subsidence measurement using a communication pipe or rod, the communication pipe or rod becomes an obstacle to construction work.
For ground subsidence measurement with a strain gauge, there are many strain gauges for concrete structures and few for soil measurements, and the initial strain amount when backfilling the boring hole for strain gauge installation is large, strain due to ground deformation There is a drawback that the direction of the meter may be misaligned, a special design is required in consideration of waterproofness and durability against underground use, and many strain gauges are required for the purpose of ground subsidence measurement. A specially designed underground strain gauge considering the above points is very expensive and not suitable for use at construction sites. In stratified ground subsidence measurement, the subsidence plate is likely to hinder the construction in the case of the subsidence method, and the pipe is likely to obstruct the construction in the case of using a pipe and a detector. It requires a skilled operator.

In the example of FIG. 2, the bottom surface of the boring hole 4 dug up to the support layer 1 for the purpose of ground investigation or the like, that is, the support layer 1
The wire 3 is raised from the weight 2 on the ground and pulled into the ground subsidence meter 6 on the ground surface 5 via the guide pulley 3a. The boring hole 4 may be filled with muddy water in order to make the wire 3 self-supporting. In this case, a self-supporting tube member or the like can be omitted.
The diameter D of the boring hole 4 is sufficient if it is equal to or larger than the diameter of the weight 2 which is relatively small. In this ground subsidence meter 6, since the point A is selected on the ground support layer 1 which is a fixed point and the point B is selected on the ground surface 5, the output corresponding to the subsidence of the ground surface 5 is output by the voltage divider 10 Can be generated from.

The ground subsidence meter 6 in the illustrated example is connected to the shaft 8 by a pulley 7 on a shaft 8 pivotally supported by a frame 7a, a constant force spring 9 mounted on the shaft 8 and the frame 7a, and an angle frame 10a. And a terminal block 11 connected to the output of the variable voltage divider 10. A preferred example of the variable voltage divider 10 is a rotary potentiometer-type variable resistor. The wire 3 from the guide pulley 3 a is locked to the pulley 7 via the wire protection device 12. The cover 13 covers the entire ground subsidence meter 6.

When the ground surface 5 rises and the distance L from the support layer 1 to the ground surface 5 increases, the tension of the wire 3 increases, so that the constant force spring 9 rotates the shaft 8 to pay out the wire 3 to keep the tension constant. keep. The variable voltage divider 10 detects a displacement of the constant force spring 9, that is, an angular displacement of the shaft 9, and gives an output to the terminal block 11 according to the displacement amount. The output of the variable voltage divider 10 in this case represents the uplift or negative subsidence of the ground surface 5.

Surface subsidence meter 6 of the present invention when the ground surface 5 subsides
However, it is obvious that the operation is the reverse of the case of the uplift, and the output of the variable voltage divider 10 represents the amount of subsidence of the ground surface 5.

Compared with a conventional device such as a strain gauge, the ground subsidence meter 6 to which the principle of the present invention is applied by using the variable voltage divider 10 and the constant load spring 9 has a strong structure and stable mechanical operation. Moreover, there is an advantage that a large output voltage is generated with respect to the input voltage and no amplifier is required.

The inventors of the present invention set the illustrated land subsidence meter 6 on the bottom to a height of 150 m.
It was confirmed that a prototype of m × 188 mm and a height of 143 mm was built, and that embankment would not interfere with the construction. In addition, with this prototype, it is possible to measure 2% accuracy, that is, subsidence of 3 m with an error range of 6 mm or less, and weight.
It was as light as 0.14tf / m, and it was confirmed that the weight of the measuring instrument does not affect the settlement. As for waterproofness, the cover
It has been found that it is sufficient to apply a grease material to the contact portion between the main body 13 and the main body and the gap portion of the terminal block 11, and further to provide an O-ring packing as the wire protection device 12.

6 and 7 show an example of a layer-based settlement total 15 in which a plurality of wires 31, 32, ... Are suspended in one boring hole 4 and the lower ends of the wires are fixed to different layers. In this example, the subsidence of each layer is detected by the surface subsidence gauge 6 similar to that shown in FIG. 2 connected to the upper end of each wire 31, 32 ....

A frame shaft 21 is integrally attached to the weight 20 at the lower end of each wire, a fixed anchor frame 22 is fixed to the frame shaft 21, and a movable anchor frame 23 is vertically movably held by the frame shaft 21. An anchor member is provided on the fixed anchor frame 22 and the movable anchor frame 23.
24 are movably attached to each other, and both anchor members 24 are rotatably connected at a connection point 25. A setting arm 26 operated from the upper end of the boring hole 4 engages with the movable anchor frame 23. Fig. 9 shows this setting arm 26
FIG.

In FIG. 7, when the weight 20 is held at a fixed position by the wire 31, the setting arm 26 is pushed down to move the movable anchor frame 23 to the position indicated by the alternate long and short dash line in FIG. Since they are connected with each other, they project in the lateral direction, project into the side wall of the boring hole 4, and hold the weight 20 at that position. After the weight 20 is thus fixed at the predetermined position of the boring hole 4, that is, at the predetermined layer, the amount of change in the distance between the ground surface 5 and each layer, that is, each weight 20, is adjusted in the same manner as in FIG. It can be detected as an output of the variable voltage divider 10 of the ground subsidence meter 6. Therefore, it is possible to measure the subsidence amount for each layer.

Even when multiple horizontal displacement gauges 40 shown in FIG. 1 are installed at substantially the same level to measure horizontal displacement, the sensor unit is basically the same as the stratification squatometer 15 in FIG. Collect the wires in one place, and pull out the ends of each wire 3 that is pulled out from them to a fixed pile 41
Then, the relative displacement between the horizontal displacement meter 40 and the fixed pile 41 can be measured. By collecting the sensor parts in one place, it is possible to avoid the obstacles to the construction as much as possible. If the horizontal displacement gauge 40 similar to the surface settlement gauge 6 in the layer-based settlement gauge 15 is used, the accuracy is unified and the cost is reduced by mass production. Can be achieved.

EFFECTS OF THE INVENTION As described in detail above, in the simple horizontal displacement meter using the variable voltage divider of the present invention, a wire is stretched between two points on the ground by a constant force spring, and the variable voltage divider is connected to the constant force spring. Two
Since the output corresponding to the displacement of the ground between the points is generated, the following effects are achieved.

(B) The displacement of the ground can be detected without affecting the construction.

(B) Since automatic measurement is possible, no skilled worker is required.

(C) The same detector structure can be applied not only to horizontal displacement gauges but also to ground subsidence gauges and layer subsidence gauges, etc., and it is possible to unify precision and reduce costs by mass production. .

[Brief description of drawings]

FIG. 1 is an explanatory view of a horizontal displacement gauge according to the present invention, FIG. 2 is an explanatory view showing the structure and operation of a ground subsidence gauge to which the present invention is applied, and FIG. 3 is a plan view of the ground subsidence gauge. 4 is the third
A front view taken along line IV-IV in the drawing, and FIG. 5 is taken along line V- in FIG.
FIG. 6 is a side view of V, FIG. 6 is a schematic plan view showing the structure of a layer-based squat meter to which the present invention is applied, FIG. 7 is a side view of a main portion of an anchor frame in the layer-based squat meter, and FIG. FIG. 9 is an explanatory diagram of the function of the frame, and FIG. 9 is an explanatory diagram of the setting arm. 1 ... Support layer, 2, 20 ... Weight, 3, 31, 32 ... Wire,
4 ... Boring hole, 5 ... Ground surface, 6 ... Ground surface subsidence meter, 7 ... Pulley, 8 ...
… Axis, 9 …… Constant force spring, 10 …… Variable voltage divider, 11 …… Terminal block, 12 …… Wire protection device, 13 …… Cover, 15 …… Layer squat gauge, 21 …… Frame shaft, 22 ...... Fixed anchor frame, 23 ...... Movable anchor frame, 24 ...... Anchor member, 25
…… Coupling point, 26 …… Setting arm, 40 …… Horizontal displacement gauge, 41 …… Fixed pile.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruichi Suzuki 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Seiji Morikawa 1-2-7 Moto-Akasaka, Minato-ku, Tokyo No. Kashima Construction Co., Ltd. (72) Inventor Toshihiko Takahashi 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Makoto Sato 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) Bibliography Sho 59-45528 (JP, U) Sho 56-29407 (JP, U)

Claims (1)

(57) [Claims] 1. A frame with a cover that can be fixedly placed on the ground surface, a wire protection device integrated with the cover, a shaft pivotally supported by the frame, and a peripheral surface of the shaft from outside the cover via the wire protection device. Wire fixed by engaging from one rotation direction,
A constant force spring having one end held in the frame and the other end fixed to engage the peripheral surface of the shaft from the opposite rotation direction, and a variable voltage divider fixed to the frame having a rotating portion coupled to the shaft. A simple horizontal displacement meter using a variable voltage divider, wherein the variable voltage divider generates an output corresponding to horizontal displacement of the ground surface between the point where the other end of the wire is fixed and the axis.