JP3764668B2 - Water path estimation method and water path estimation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water channel estimation method and a water channel estimation device.
[0002]
[Prior art]
Conventionally, in-situ tests such as permeability tests and tomography measurements have been carried out in order to investigate the surrounding rock mass and ground using boreholes that are carried out to grasp geological surveys and hydraulic characteristics. . Using these results, information necessary for construction of civil engineering structures is obtained.
[0003]
FIG. 8 is a schematic view of a conventional interpore permeability test apparatus. In the ground 101, two boring holes 103 and a boring hole 105 are excavated in advance. In the boring hole 103 used as a water feeding device, a transmission section 109 is provided between the packers 107. In the boring hole 105 used as a receiving device, a plurality of receiving sections 113 are provided between the packers 111. Water is injected from the transmission section 109 of the boring hole 103, the pressure response is observed in the receiving section 113 of the boring hole 105, and the water channel between the holes is estimated.
[0004]
[Problems to be solved by the invention]
However, the conventional method is not efficient in terms of time and cost because the transmitter and receiver test devices are installed in the drilled holes that have been excavated in advance.
[0005]
The present invention has been made in view of such a problem, and the object of the present invention is to provide a water path estimation method and a water path capable of obtaining results equivalent to a simple water permeability test in a short time and economically. It is to provide an estimation device.
[0006]
[Means for Solving the Problems]
According to a first invention for achieving the above-mentioned object, a pressure gauge is provided by cutting a first boring hole in the ground, closing a predetermined portion in the first boring hole with a packer. A water channel estimation method characterized in that a receiving section is formed, a second boring hole is drilled by a boring machine and a drilling situation is recorded, and a water pressure in the receiving section is acquired using the pressure gauge. It is.
[0007]
The first bore hole drilled in the ground is used as a receiving device. One or more receiving sections are formed in the first boring hole, and a pressure gauge is provided in each receiving section. The second boring hole in the middle of drilling is used as a water supply device. The second boring hole is drilled at at least one place and can be arranged at an arbitrary place. Of the drilling status of the second boring hole, for example, the drilling water pressure of the boring machine is compared with the water pressure acquired in the receiving section, and the water path between the first boring hole and the second boring hole is compared. Estimate the position.
[0008]
In the first invention, a predetermined section in the first boring hole drilled in the ground is closed with a packer to form a receiving section. A pressure gauge is provided in the reception section. Next, the second boring hole is drilled with a boring machine to record the state of digging, and the water pressure in the receiving section is acquired using a pressure gauge provided in the receiving section.
[0009]
According to a second aspect of the present invention, a pressure gauge provided in a receiving section formed by closing a first boring hole drilled in the ground with a packer, and a second boring hole drilled in the ground A boring machine, and a data acquisition means for acquiring the water pressure measured using the pressure gauge and the drilling status of the boring machine, and comparing the water pressure with the drilling status to determine the first boring hole And a second water-hole estimating device for estimating a water-hole position between the second boring hole.
[0010]
In the second aspect of the invention, the water pressure is measured with a pressure gauge provided in a receiving section formed by closing the first bored hole in the ground with a packer. Also, the second boring hole is drilled using a boring machine. At the time of excavation of the second boring hole, the water pressure measured by the pressure gauge and the excavation status of the boring machine are acquired by the data acquisition means. By comparing the water pressure and the excavation status, the position of the water channel between the first bore hole and the second bore hole is estimated. Data acquisition means may be provided for each of the water pressure and the excavation status.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a water channel estimation apparatus A. As shown in FIG. 1, the water channel estimation apparatus A is a No. 1 excavated in the ground 1. 2 Pressure gauges 33a, 33b, 33c, 33d, 33e provided in the borehole 7, computer 39, No. 2 1 boring hole 4 and no. 3 is constituted by a pump 15 of a boring machine 19 that is drilling the boring hole 5, a pressure supply device 17, and the like. No. The 2 boring hole 7 is used as a receiving device of the water channel estimating device A. 1 boring hole 4, no. The 3 boring hole 5 is used as a water supply device.
[0012]
The two boring machines 19 are no. 1 boring hole 4, no. The rod 11 is inserted into the three boring holes 5, the bit 9 is attached to the tip of the rod 11, the pressure supply device 17 is installed on the ground 1, the pump 15 and the like. The boring machine 19 applies appropriate pressure to the bit 9 with the pressure supply device 17 while feeding water from the pump 15 through the hose 13. 1 boring hole 4, no. 3 Drill the bore 5.
[0013]
No. 1 boring hole 4, no. During the drilling of the three boring holes 5, the excavation status is managed and recorded. The excavation status is information such as the drilling depth and time, the drilling water pressure of the boring machine 19, the number of revolutions, the water supply amount, the drainage amount, the supply pressure, the excavation speed, and the like.
[0014]
FIG. It is sectional drawing which shows the installation process of the packer in the 2 boring hole 7, and a pressure gauge. No. The 2 boring hole 7 is excavated in the ground 1 in advance using a machine similar to the boring machine 19. The packers 21a, 21b, 21c,..., 21f are made of a material that can be contracted and expanded, such as rubber. The cables 35 are passed through the packers 21a, 21b, 21c..., And pressure gauges 33a, 33b, 33c. As shown in FIG. 2, the packers 21a, 21b, 21c,. 2 are inserted into the boring holes 7 and arranged at predetermined positions.
[0015]
As shown in FIG. 1, the packers 21a, 21b, 21c, 21d, 21e, and 21f arranged at predetermined positions are inflated. 2 The boring hole 7 is closed. The receiving section 2-a is between the packer 21a and the packer 21b, the receiving section 2-b is between the packer 21b and the packer 21c, and the receiving section 2-c is between the packer 21c and the packer 21d. The receiving section 2-d is formed between the packer 21e and the receiving section 2-e, and the receiving section 2-e is formed between the packer 21e and the packer 21f.
[0016]
Pressure gauges 33a, 33b, 33c, 33d, and 33e are installed in the reception section 2-a, the reception section 2-b, the reception section 2-c, the reception section 2-d, and the reception section 2-e, respectively. The pressure gauges 33a, 33b, 33c, 33d, and 33e are connected to the amplifier 37 and the computer 39 on the ground 1 via the cable 35. The computer 39 measures the water pressure in the receiving section 2-a, the receiving section 2-b, the receiving section 2-c, the receiving section 2-d, and the receiving section 2-e measured by the pressure gauges 33a, 33b, 33c, 33d, and 33e. Is obtained via the amplifier 37.
[0017]
Next, operation | movement of a water path estimation apparatus is demonstrated.
Water is fed from the pump 15 through the hose 13 of the boring machine 19 and an appropriate pressure is applied to the bit 9 by the pressure supply device 17. 1 boring hole 4, no. 3 Drill a bore 5. During excavation, the excavation status is managed and recorded. The excavation status is information such as the drilling depth and time, the drilling water pressure of the boring machine 19, the number of revolutions, the water supply amount, the drainage amount, the supply pressure, the excavation speed, and the like.
[0018]
At the same time, no. 2 On the borehole 7 side, the water pressure in the receiving section 2-a, the receiving section 2-b, the receiving section 2-c, the receiving section 2-d, and the receiving section 2-e is changed to the pressure gauges 33a, 33b, 33c, 33d, Measure at 33e. The computer 39 acquires water pressure change data via the amplifier 37.
[0019]
FIG. 3 is a diagram showing the result of pressure monitoring when the elapsed time is represented on the horizontal axis and the water pressure is represented on the vertical axis. Curves shown in 2-b section 41, 2-c section 43, 2-d section 45, and 2-e section 47 are reception section 2-b, reception section 2-c, reception section 2-d, and reception section 2 respectively. -E shows the time course of the water pressure observed at -e. No. For No. 1 boring drilling 49 (oval mark), no. The time for drilling 1 boring hole 4 is At the time of 3 boring drilling 51 (rectangular mark), no. 3 shows the time for drilling the bore 5.
[0020]
No. 1 boring hole 4 and no. 3 boring holes 5, No. 2 when the water permeability of the ground 101 between the two boring holes 7 is large. 1 boring hole 4, no. No. 3 drilling water fed from the pump 15 to the bit 9 during the drilling of the 3 boring hole 5 flows into the ground 101 and No. 3 A response is seen in the water pressure observed in the receiving section 2-b, the receiving section 2-c, the receiving section 2-d, and the receiving section 2-e.
[0021]
For example, no. At the time of 3 boring drilling 51a, responses are seen in the curves shown in the 2-b section 41, the 2-c section 43, and the 2-d section 45. Therefore, no. In the depth corresponding to 51a at the time of 3 boring drilling, No. It can be estimated that the 3 boring holes 5, the receiving section 2-b, the receiving section 2-c, and the receiving section 2-d have high continuity.
[0022]
Further, the curve shown in the 2-e section 47 has a very small response compared to the curves shown in the other 2-b section 41, 2-c section 43, and 2-d section 45. Therefore, in the receiving section 2-e at the deepest position, No. 1 boring hole 4 and no. It can be determined that the continuity with the 3 boring holes 5 is small.
[0023]
FIG. 3 shows the results of pressure response monitoring when the borehole depth is expressed on the horizontal axis and the water pressure and the water injection pressure are expressed on the vertical axis. Curves shown in 2-b section 53, 2-c section 55, 2-d section 57, and 2-e section 59 are reception section 2-b, reception section 2-c, reception section 2-d, and reception section 2, respectively. The change in the response value of the water pressure observed at −e is shown. The drilling water injection pressure 61 (triangular mark) indicates the drilling water injection pressure of the boring machine 19 at each drilling depth.
[0024]
In FIG. There is a difference in the response value of the water pressure depending on the depth of the 3 boring holes and 5 holes. The greater the pressure response, the No. at that drilling depth. It can be estimated that the water permeability between the 3 boring holes 5 and the receiving section 2-b, the receiving section 2-c, the receiving section 2-d, and the receiving section 2-e is large.
[0025]
In order to verify that the location of the water channel can be estimated by comparing the excavation status of the borehole on the water supply device side and the pressure response at the borehole on the receiver side, a Lugion test was conducted. That is, no. 3 Water is poured from the bore 5 and The pressure response at the two bore holes 7 was observed.
[0026]
FIG. It is a figure which shows the test area which poured water by 3 boring hole. No. 3 The boring hole 5 is closed by a packer or the like (not shown) to form a test section 3-a, a test section 3-b, a test section 3-c, a test section 3-d, and a test section 3-e. . In FIG. 4, these test sections are located at the depths indicated by test section 3-b63, test section 3-c65, test section 3-d67, and test section 3-e69.
[0027]
FIG. No. 2 in the receiving section 2-c and the receiving section 2-d of the boring hole 7. It is a figure which shows the pressure response result observed at the time of 3 boring hole 5 drilling, and a lugion test. The horizontal axis is the pressure side position, and the vertical axis is No. 2 is the response pressure at the borehole 7. The position on the pressure side shown on the horizontal axis is No. 3 is a test section 3-b, a test section 3-c, a test section 3-d, and a test section 3-e on the boring hole 5 side.
[0028]
No. No. 3 when the Lugion test was conducted in each test section of the 3 boring hole 5. Response pressures in the receiving section 2-c and the receiving section 2-d of the two boring holes 7 are shown as response pressures 87c and 87d (broken lines), respectively. No. The response pressures in the receiving section 2-c and the receiving section 2-d when the depth of each test section of the 3 boring hole 5 is cut are shown as response pressures 89c and 89d (broken lines), respectively. In addition, the response pressure of FIG. 6 has shown the value at the time of converting all the pressurization sides into 100 kPa.
[0029]
As shown in FIG. 6, the response pressures 87c and 87d at the time of the lugion test and the response pressures 89c and 89d at the time of drilling show the maximum response values with respect to the pressurization in the test section 3-b. Therefore, in any of the Lujion test and the water channel estimation method of the present embodiment, there is a water channel between the test section 3-b and the reception section 2-c, and between the test section 3-b and the reception section 2-d. It can be estimated that there is.
[0030]
In addition, although the response pressures 87c and 87d at the time of the lugion test decrease with respect to the pressurization in the test section 3-d and the test section 3-e, the response pressures 89c and 89d at the time of drilling increase. And the results do not match. The reason for this is that the injection water during the Lujion test is injected only from the test section blocked by the packer, whereas the drilling water during boring has a flow that returns to the ground, so the section is shallower than the drilling depth. It is considered that drilling water flows into the bedrock. In this case, as shown in FIG. 4, there is a section with a large pressure response near the depth of 24 m above the test section 3-d67, that is, a section where water permeability can be estimated to be large. It can be estimated that it was affected by the inflow.
[0031]
As described above, in the water channel estimation device A, No. 1 is drilling with the boring machine 19 as a water feeding device. 1 boring hole 4, no. Since the 3-boring hole 5 is used and the pressure response to the drilling water is observed, a result equivalent to the conventional water permeability test can be obtained in a short time. Moreover, since the water supply device can be simplified, it is economical.
[0032]
In this embodiment, as the water channel estimation device A, three boring holes are arranged on a straight line, and the two boring holes that are water feeding devices are drilled almost simultaneously, but the number and positions of the boring holes This does not apply to the drilling time of water supply equipment. There shall be at least one water supply device for one receiving device. In the case of using a plurality of water feeding devices, it is possible to estimate the water channel efficiently and accurately by appropriately planning the hole arrangement and the drilling order. Moreover, the receiving section formed in the boring hole used as a receiving device can be set to an arbitrary quantity or position.
[0033]
Furthermore, in addition to the method of estimating the position of the water path by comparing the drilling water pressure of the boring machine 19 and the response pressure in the receiving section, the water supply amount, drainage amount, supply pressure, rotation speed, excavation speed, etc. of the boring machine 19 The method of using the data of can be considered.
[0034]
In the tests whose results are shown in FIGS. 3 to 6, as shown in FIG. 1 borehole 4 is in the mudstone dominant layer 81, Two boreholes 7 are formed in the mudstone dominating layer 81 and conglomerate 83, The three boreholes 5 are located in the conglomerate 83 layer and the sandstone dominant layer 85. When it was difficult to maintain the hole wall in the bare hole, a PVC casing was installed in the borehole.
[0035]
FIG. 7 is an enlarged cross-sectional view in the vicinity of the receiving section or test section in the borehole where the PVC pipe 97 is installed. A PVC pipe 97 is inserted into the borehole, and a strainer 93 is disposed at a position corresponding to the reception section or the test section. Between the PVC pipe 97 and the surrounding rock mass 99 is bentonite pellet 91, and between the strainer 93 and the upper and lower portions of the PVC pipe 97 and the surrounding rock mass 99 is filled with silica sand 95.
[0036]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a water channel estimation method and a water channel estimation device capable of obtaining results equivalent to a simple permeability test economically in a short time.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a water channel estimation device A. FIG. 2 is a cross-sectional view showing a process of installing a packer and a pressure gauge in a borehole 3. FIG. 3 is a diagram showing the results of pressure monitoring. FIG. 5 shows the results. 3 is a diagram showing a test section in which water is injected through the bore 5; No. 2 in the receiving section 2-c and the receiving section 2-d of the boring hole 7. Fig. 7 shows the pressure response results observed during drilling of 5 bore holes and during the Lugion test. Fig. 7 is an enlarged cross-sectional view of the receiving section or the vicinity of the test section in the bore hole where the PVC pipe 97 is installed. Schematic diagram of inter-permeability test equipment 【Explanation of symbols】
1 ……… Ground 4 ……… No. 1 boring hole 5 3 boring hole 7 2 boring hole 9 ... bit 15 ... pump 19 ... boring machine 21a, 21b, 21c, 21d, 21e, 21f ... packer 33a, 33b, 33c, 33d, 33e ... pressure gauge 87c, 87d, 89c, 89d ... …… Response pressure

Claims (9)

Drill the first boring hole in the ground,
A predetermined portion in the first boring hole is closed with a packer to form a receiving section provided with a pressure gauge,
A water channel estimation method, wherein a water pressure in the receiving section is acquired using the pressure gauge while recording a state of excavation by drilling a second boring hole with a boring machine. The drilling condition includes at least one of a drilling depth and time, a drilling water pressure, a rotation speed, a water supply amount, a drainage amount, a supply pressure, and a drilling speed of the boring machine. Water path estimation method. The water channel estimation method according to claim 2, wherein the position of the water channel is estimated by comparing the drilling water pressure and the water pressure in the excavation state. The method according to claim 1, wherein the receiving section is formed at a plurality of locations in the first boring hole. 2. The water channel estimation method according to claim 1, wherein at least one second boring hole is drilled. A pressure gauge provided in the receiving section formed by closing the first boring hole drilled in the ground with a packer;
A boring machine for drilling a second boring hole in the ground;
Data acquisition means for acquiring the water pressure measured using the pressure gauge and the drilling status of the boring machine;
Comprising
A water channel estimation apparatus that compares the water pressure with the excavation status and estimates a position of a water channel between the first bore hole and the second bore hole. The drilling status includes at least one of a drilling depth and time, a drilling water pressure, a rotation speed, a water supply amount, a drainage amount, a supply pressure, and a drilling speed of the boring machine. Water path estimation device. The water channel estimation device according to claim 6, wherein the reception section is formed at a plurality of locations in the first boring hole. The water channel estimation apparatus according to claim 6, wherein at least one of the second bore holes is drilled.

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