JP3134021B2 - Pressurizing device for horizontal loading tester in bore - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for supplying pressurized water to a measuring sonde in a horizontal loading tester in a borehole, and more particularly to measuring water for measurement from a water storage tank by a low pulsation pump. The present invention relates to a pressurizing device having a structure for pumping water to a sonde and obtaining a water supply amount from a change in water level in a water storage tank.

[0002]

2. Description of the Related Art In the basic design of a structure, horizontal mechanical characteristics of the ground at an original position, ground coefficient (K value),
It is extremely important to know the yield strength and ultimate bearing capacity. As a test method therefor, there is a horizontal loading test using a borehole. Various types of horizontal loading test machines have been developed, and a typical example is an evenly distributed load type. In this method, a horizontal loading force is applied to the hole wall by injecting water into a rubber tube of a measuring sonde inserted into a borehole and expanding the rubber tube. Exams are usually
This is performed by obtaining the load applied to the hole wall and the change in the hole diameter from the pressure of the injected water and the amount of water supplied.

[0003] A cylinder gas is generally used as a pressure source of this tester. In this method, high-pressure nitrogen gas filled in a cylinder is supplied through a needle valve into a steel volume meter tank on the ground, and the pressure in the water in the volume meter tank is adjusted by the gas pressure. in this case,
By reading the water level on the liquid level display section of the capacity meter tank, the amount of water supply is determined.

[0004]

A pressurizing apparatus using a cylinder gas has the advantage that the apparatus configuration is simple and can be easily implemented. On the other hand, since a high-pressure gas is used, various pressurizing apparatuses described below are used. There was a problem. Steel tanks and nitrogen gas cylinders are required, making the test machine heavy and difficult to transport on slopes and seas. It is necessary to be regulated by the "High Pressure Gas Control Law", and it is necessary to submit a notification as a high pressure gas manufacturer and conduct a pressure test once a year. In addition, a safety device is required that is independent of the performance of the test machine, which makes the test machine even heavier. In general, no matter how carefully a device using high-pressure gas is designed and manufactured, there is no danger that cracks or breakage may occur due to unexpected handling or the like not following an operation manual or the like. This type of testing machine is no exception, and requires a thorough inspection before each use. However, this inspection work is complicated and time-consuming.

In the gas pressurization method, since the gas is compressible, the response of pressurization is low, and it is difficult to control step pressurization. This is because skill is required to adjust to a predetermined test pressure. Also, it is not suitable for testing with strain control.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to simplify the prior inspection by directly supplying water under pressure without using high-pressure gas, thereby improving workability. An object of the present invention is to provide a pressurizing apparatus for a horizontal loading test machine in a hole, which is excellent, can reduce the weight of the test machine, and is suitable for computer control.

[0007]

According to the present invention, water is press-fitted into a rubber tube of a measuring sonde inserted into a boring hole and expanded to apply a horizontal loading force to the hole wall. This is a pressurizing device for a horizontal loading tester in a hole that determines the load applied to the wall and the change in hole diameter. In order to achieve the above object, according to the present invention, there is provided a water storage tank having means for storing water for measurement therein and measuring a fluctuation in the water level, and pumping the water in the water storage tank into a rubber tube of a measurement sound. And a pressure measuring means for measuring the internal pressure of the measuring sonde.

Furthermore the water supply piping is provided with a water supply port and the control valve, it allows water water for measuring the water tank from the water inlet share the low pulsation pump. Here, a gear pump is preferable as the low pulsation pump, but a vane pump, a screw pump, or the like can also be used. In addition, the computer controls the rotation of the low-pulsation pump based on a water level sensor output signal indicating the water level of the water storage tank and a pressure sensor output signal indicating the pressure of the measuring probe, and performs a loading test according to a predetermined pressurized water supply program. It can also be configured as follows. In that case, fuzzy control is preferred.

[0009]

[Function] The measuring water stored in the water storage tank is
It is pumped to the measuring sonde by a low pulsation pump. The internal pressure of the measuring sonde can be measured by the pressure measuring means, and the amount of water supply at that time can be calculated by obtaining the water level fluctuation amount of the water storage tank. Since the pump used has a small pulsation, it is easy to keep the pressure constant, and even if the pump is stopped, the constant pressure can be maintained. In addition, forward and reverse rotation is possible, and by providing a water supply system pipe having a water supply port and a control valve separately, water can be supplied to the water storage tank using the pump. Since the low pulsation pump can electrically control the amount of water supplied, computer control can be easily performed by providing necessary sensors in each section.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an in-hole horizontal load tester using a pressurizing device according to the present invention. The horizontal loading tester in the hole
Insert the measuring sonde 12 into the borehole 10,
Water is pressed into the rubber tube 14 to expand it, and the hole wall 1 is expanded.
6 is a one-distribution load type one-chamber system in which a horizontal loading force is applied to the chamber 6 to determine a load applied to the hole wall and a change in the hole diameter from the water supply pressure and the water supply amount. The pressurizing device installed on the ground includes a water storage tank 20 for storing water for measurement, and a gear pump 26 including a gear pump main body 22 and a driving motor 24.
The water storage tank 20 has a guide rod 28 provided in the interior thereof in a vertical direction, a float 30 movable vertically along the guide rod 28, and a water level sensor 32 for detecting the position of the float 30. A pressurizing system pipe 34 connects between the lower part of the water storage tank 20 and the gear pump main body 22 and between the gear pump main body 22 and the measurement sonde 12. A three-way control valve 36 is inserted between the gear pump main body 22 and the measuring sonde 12, and a water supply system pipe 4 having a water supply port 38 provided therein.
0 is connected. Also, a first pressure gauge 42 is provided on the measurement sound side of the pressurized system pipe 34, and the measurement sound 1
2 is pulled out to the ground using a pressure hose 44, and a second pressure gauge 46 is installed.

The measurement using this pressurizing device is performed in the following procedure. First, the water supply port 38 is put into an appropriate water source, and the three-way control valve 36 is operated to form a flow path from the water supply system pipe 40 to the gear pump main body 22. Then, by rotating the gear pump 26 in the reverse direction, the water of the water source is pumped up from the water supply port 38 through the water supply system pipe 40 and sent into the water storage tank 20 to secure a necessary amount of water. Then, the position of the float 30 at the start of the test is read by the water level sensor 32 in advance.

Next, the three-way control valve 36 is switched to operate so as to cut off communication with the water supply system pipe 40 and communicate with the measuring sonde 12. The gear pump 26 is driven to rotate forward to pump the water in the water storage tank 20 into the rubber tube 14 of the measuring sound 12. As a result, pressure is applied to the measurement water, and the rubber tube 14 of the measurement sonde 12 expands with the pressurized water to apply a horizontal loading force to the hole wall 16. The adjustment of the pressing force can be performed by electrically controlling the operation of the gear pump 26. At this time, the pressure in the measuring sonde 12 can be measured by the second pressure gauge 46, and
The position of the float 30 within 0 is read and can be calculated from the difference from the start of the test. Therefore, the load applied to the hole wall and the change in the hole diameter are obtained from the water supply pressure and the water supply amount. The first pressure gauge 42 is used to monitor the discharge pressure of the gear pump 26.

Here, it is conceivable to measure the amount of water supplied to the measuring sonde using a flow meter. However, in this method, when measuring a very small flow rate, the accuracy is low and the apparatus becomes complicated. Absent. On the other hand, the configuration for obtaining the water supply amount from the change in the water level of the water storage tank 20 as in the present invention is preferable because the device is simplified and the accuracy is increased.

FIG. 2 shows another embodiment of the present invention. This is configured so that the entire loading test process can be automatically performed by computer control. The pressurizing device includes a water storage tank 50 for storing water for measurement, and a gear pump 56 including a gear pump main body 52 and a driving motor 54. In the water storage tank 50, a guide rod 58 provided in the interior thereof in a vertical direction, a float 60 movable vertically along the guide rod 58, and the position of the float 60 (ie, water level)
Is provided. The piping is connected between the lower part of the water storage tank 50 and the gear pump main body 52, and between the gear pump main body 52 and the measuring sonde. A first three-way control valve 66 is inserted between the water storage tank 50 and the gear pump main body 52, and a water supply port 68 and a pipe 70 having a filter 69 are connected thereto. Connect to the measuring sonde 2
A first pressure sensor 72 is provided on one of the pipes 74a, and a second pressure sensor 76 is provided on the other pipe 74b. A second three-way control valve 78 is provided in a pipe between the pipe 74a and the gear pump main body 52. Further, a connection is made between the pipe 74b and the water storage tank 50 by a pipe, an on-off valve 79 is provided in the middle thereof, and the pipe is connected to the second three-way control valve 78 at a position near the water storage tank by a pipe.

These are controlled by a CPU (personal computer) 80. Analog output signals from the magnetostrictive sensor 62 and the first and second pressure sensors 72 and 76 are converted into digital signals by the A / D converter 82 and input to the CPU 80. The output of the CPU 80 controls the opening and closing of each of the valves 66, 78, 79 via a digital I / O 82, and is converted into an analog signal by a D / A converter 84, and the second pressure indicating the pressure of the measuring sonde. The output of the sensor 76 is compared with a comparator 86, and the operation of the gear pump 56 is controlled based on the comparison result. In addition,
The control of these pumps and the like may be general digital control, but fuzzy control incorporating a fuzzy chip is closer to the operation of a skilled worker, and control is smoother.

This device can be automatically measured by a predetermined load test program stored in the CPU 80 in advance.
First, the water supply port 68 is put into an appropriate water source, and the measurement sonde is started from a state where it is installed at a predetermined position in the borehole. The first and second three-way control valves 6 are controlled by the CPU 80.
6, 78, the on-off valve 79 is closed, and the water supply port 68
To the first three-way control valve 66 → the gear pump main body 52 → the second
A piping route from the three-way control valve to the water storage tank 50 is formed. And, by driving the gear pump 56 forward,
The water of the water source is pumped into the water storage tank 50 to secure necessary measurement water. The water level data is detected by the magnetostrictive sensor 62 and the CPU 80 determines whether or not the required water amount has been secured.

Next, the first and second three-way control valves 66, 7
8 from the water storage tank 50 to the gear pump main body 5.
2 to the pipe 74a to the measuring sonde. Then, based on a preset load test program, the CPU 80 compares the output of the second pressure sensor 76 with the gear pump 56 to pump the water in the water storage tank 50 into the measuring sonde. Therefore, in this case, the gear pump 56 may rotate in only one direction. The pressure is applied to the measuring water by the above operation, and the rubber tube of the measuring sonde is expanded by the pressurized water to apply a horizontal loading force to the hole wall. The amount of water supply at that time can be obtained by reading the position of the float 60 in the water storage tank 50 with the magnetostrictive sensor 62 and calculating the difference from the start time by the CPU 80. The data indicating the pressing force and the amount of water supply is stored in the CPU 8 every moment.
0 can be recorded. The load applied to the hole wall and the change in the hole diameter are determined from the water supply pressure and the water supply amount. The first pressure sensor 72
Are used to monitor the discharge pressure of the gear pump 56. The on-off valve 79 can also be used to adjust the pressure of the measuring sonde, and can be used to store the measuring water storage tank 50 after measurement.
It can also be used for recovery to

[0018]

As described above, the present invention directly pressurizes water for measurement and does not use high-pressure gas.
It is not subject to the regulations of the High Pressure Gas Control Law, and inspection work before use can be simplified and workability is improved. Further, since the liquid level fluctuation is used for measuring the amount of water supply, accurate and easy measurement can be performed even with a small flow rate. Further, the pressurizing device of the present invention can use a conventional measuring sonde as it is.

In the present invention, since water is pressurized by using a low pulsation type pump, pulsation is small, the pressure is easily maintained at a constant level, and the pressure can be maintained even when the pump is stopped. improves. Also, pumping of water for measurement becomes possible, and the weight of the entire system can be reduced. Suitable for computer control, measurement can be performed efficiently without requiring the skill of an operator.

In the present invention, since incompressible water is pressurized unlike gas, the response of pressurization is fast, and therefore control of step pressurization is easy. In the case of performing a test by distortion control, an accurate test cannot be performed unless the response is fast, but in that respect, the apparatus of the present invention is suitable for a test of distortion control.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an in-hole horizontal load tester using a pressurizing device according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of the pressurizing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Boring hole 12 Measurement sonde 14 Rubber tube 16 Hole wall 20 Water storage tank 26 Gear pump 30 Float 32 Water level sensor 34 Pressurized system piping 36 Three-way control valve 38 Water supply port 40 Water supply system piping 42 First pressure gauge 46 Second pressure Total

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 1/00-1/08 E21B 49/00-49/10

Claims (2)

(57) [Claims] 1. A method for injecting water into a rubber tube of a measuring sonde to be inserted into a borehole and expanding the same so as to apply a horizontal loading force to the hole wall. In the test machine to be sought, a water storage tank equipped with a means for storing the water for measurement and measuring the fluctuation of the water level, a pressurized system pipe for pressure-feeding the water in the water storage tank into the rubber tube of the measurement sonde, and in the middle And a pressure measuring means for measuring the internal pressure of the measuring sonde , and further comprising a water supply port and a control valve.
Water supply piping, water supply port shared with the low pulsation pump
A pressurizing device for a horizontal load testing machine in a hole, characterized in that water for measurement can be supplied to a water storage tank from above . 2. A computer controls the rotation of the low pulsation pump according to a water level sensor output signal indicating the water level of the water storage tank and a pressure sensor output signal indicating the pressure of the measuring probe, and according to a predetermined pressurized water supply program. The pressurizing device according to claim 1, wherein a load test is performed.