JP2023057265A - Earth Pressure Shield Excavator with Sampling Device and Earth Pressure Shield Construction Method - Google Patents

Abstract

To provide an earth pressure shield excavator with a sampling device capable of collecting excavated soil in a chamber even during excavation, and an earth pressure shield construction method.SOLUTION: An earth pressure shield excavator 1 with a sampling device includes a through hole 21 passing through a partition wall 5, a water stop valve 22 connected to the through hole 21, a sampling tube 23 detachably connected to the water stop valve 22, pressure adjusting means for applying negative pressure to the inside of the sampling tube 23, and a depressurization valve 25 connected to a body of the sampling tube 23. The excavated soil 10 in a chamber 6 can be pulled into the sampling tube 23.SELECTED DRAWING: Figure 2

Description

The present invention relates to an earth pressure shield excavator with a sampling device and an earth pressure shield construction method used when constructing a shield tunnel.

In the construction of shield tunnels, the mud pressure shield method, which is classified as one of the earth pressure shield methods, is widely used because it can be applied to a wide range of geological features and can be used even under large cross-sections and high soil water pressure.

In the earth pressure type shield construction method (mud pressure shield construction method), the excavated soil excavated by the cutter head is taken into the chamber formed between the cutter head and the partition wall, and the excavated soil taken into the chamber is agitated by a stirrer. At the same time, the excavated soil is given plastic fluidity by injecting additives, etc., and the excavated soil with plastic fluidity is pressed against the face by the propulsive force of the shield, etc., and excavated while applying earth pressure to the face. In addition to suppressing the collapse of the face ground due to stress release, the surplus excavated soil can be smoothly discharged from the chamber using a screw type earth removing device.

In this earth pressure shield construction method, it is important that the excavated soil filled in the chamber has appropriate plastic fluidity, uniformity, and water impermeability (hereinafter referred to as plastic fluidity, etc.) in order to stabilize the face. Such plastic fluidity of the excavated soil is greatly affected by the geology and particle size distribution of the ground to be excavated, and the additives used and their amounts.

Therefore, conventionally, during construction, a sample is collected from the excavated soil discharged from the chamber by a screw type earth discharging device, and based on the collected sample, the geology of the excavated ground, the particle size distribution, and the appropriate amount of additive material to be used are determined. I was trying to grasp whether it was.

However, since the sample of the excavated soil is taken from the chamber after passing through the screw-type discharge device, there is a risk that the quality of the excavated soil may change over time during the discharge process. There was a problem that it was difficult to grasp the

In addition, when a defect was found in the plastic fluidity of the sample of the excavated soil collected from the chamber by the screw discharge device, it was unclear at which position of the face the excavated soil with the defect was excavated. .

Therefore, a method has been developed in which a screw (hereinafter referred to as a sample-collecting screw) is provided through the partition wall of the shield machine, and a sample is collected by directly taking out the excavated soil in the chamber by rotating the sample-collecting screw ( For example, see Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-6825

However, in the conventional technology as described above, when a sample-collecting screw is installed, a wide space behind the bulkhead of the shield excavator is required for pulling out the sample-collecting screw. There was a problem that the size of the

In addition, the tip of the screw for sampling needs to protrude from the end face of the partition wall on the chamber side in order to take in the excavated soil. There was a problem that it could not be used during excavation because there was

Furthermore, even when the sample-collecting screw and the stirrer, etc., are arranged in a position where they do not contact each other, there is a possibility that the device will be damaged if gravel or the like gets caught between the sample-collecting screw and the stirrer, etc.

SUMMARY OF THE INVENTION Therefore, in view of such conventional problems, the present invention has been made for the purpose of providing an earth pressure shield excavator equipped with a sample sampling device and an earth pressure shield construction method capable of sampling excavated soil in a chamber even during excavation. It is.

The feature of the invention described in claim 1 for solving the conventional problems as described above is to impart plastic fluidity to the excavated soil taken into the chamber formed between the cutter head and the partition wall, thereby An earth pressure type shield excavator equipped with a sampling device for excavating while applying earth pressure to a through hole penetrating the partition wall, a water shutoff valve connected to the through hole, and attached to and detached from the water shutoff valve. a sampling tube operably connected thereto; pressure regulating means for applying a negative pressure in said sampling tube; It is to be able to be drawn into the sample collection tube.

The feature of the invention according to claim 2 resides in that, in addition to the configuration of claim 1, the pressure adjusting means can pressurize the inside of the sample collection tube.

The feature of the invention according to claim 3 is that, in addition to the configuration of claim 1 or 2, the pressure adjusting means comprises a piston slidably inserted into the sample-collecting tube and an operating means for sliding the piston. It consists of

The feature of the invention according to claim 4 is that, in addition to the configuration of claim 1 or 2, the pressure adjusting means is connected to a supply/discharge pipe connected to the sample collection pipe via the supply/discharge pipe. It consists of a pump.

A feature of the invention according to claim 5 resides in that, in addition to the structure of claim 4, there is provided a fluid pressure-feeding means for pressure-feeding a fluid into the sample-collecting pipe through the supply/discharge pipe.

The feature of the invention according to claim 6 is that, in addition to the configuration according to any one of claims 1 to 5, the sample collection tube has a window for checking the inside in the body portion.

The feature of the invention according to claim 7 is that, in addition to the configuration according to any one of claims 1 to 6, a plurality of through holes are provided, and excavated soil in the chamber is placed in the sampling pipe at each position of each through hole. I made it so that I could be drawn into it.

The feature of the invention according to claim 8 is that, in addition to the configuration of claim 7, the sample collection tube is detachably provided, and the additive material injection means can be connected to the water stop valve instead of the sample collection tube. It is in.

The feature of the invention according to claim 9 is that the excavated soil taken into the chamber formed between the cutter head and the partition wall is made to have plastic fluidity, and the excavated soil is excavated while applying soil pressure to the face. In the shield construction method, a water stop valve connected to a through hole that penetrates the partition wall is used, and a negative pressure is applied to a sampling pipe connected to the water stop valve during excavation, so that the sample pipe is connected to the chamber. To take in the excavated soil inside and evaluate the properties of the collected excavated soil.

The feature of the invention according to claim 10 is that, in addition to the configuration of claim 9, the condition of the excavated soil in the chamber during excavation is measured at any time by a measuring means, and when an abnormal value is measured by the measuring means The object is to collect the excavated soil.

In addition to the configuration of claim 9, the feature of the invention according to claim 11 is that the geology of the ground to be excavated is surveyed in advance, and the excavated soil is collected in a range where the geology is expected to change due to the survey. It is in.

The feature of the invention according to claim 12 is that, in addition to the configuration of any one of claims 9 to 11, a plurality of through-holes are provided, and the excavated soil taken into the sampling pipe at each position of each through-hole has plasticity. Fluidity is evaluated, and an additive injection means is connected to the water stop valve in place of the sampling pipe that takes in the excavated soil at the position where the plastic fluidity is judged to be insufficient, and the plastic fluidity is determined to be insufficient. To inject an additive into excavated soil at a position determined to be insufficient.

The soil pressure type shield excavator with a sampling device according to the present invention is equipped with the configuration described in claim 1, so that excavated soil in the chamber can be directly sampled even during excavation.

Further, in the present invention, by providing the configuration described in claim 2, the excavated soil remaining in the sampling pipe can be discharged from the chamber side or other openings by pressurization.

Further, in the present invention, by providing the configuration described in claim 3, it is possible to apply negative pressure and pressurize the inside of the sample collection tube with a simple structure.

Further, in the present invention, by providing the configuration according to claim 4, it is possible to efficiently apply a negative pressure to the inside of the sample collection tube.

Further, in the present invention, the inside of the sample collection tube can be cleaned with the fluid by providing the configuration according to claim 5 .

Moreover, in the present invention, by providing the configuration described in claim 6, it is possible to confirm that the excavated soil has been taken into the sampling tube.

Further, in the present invention, by providing the configuration of claim 7, it is possible to check the state of the excavated soil at a plurality of locations in the chamber.

Moreover, in the present invention, by providing the configuration according to claim 8, it is possible to efficiently inject the additive material into the position where adjustment is required.

Further, in the present invention, by providing the configuration of claim 9, even during excavation, the excavated soil in the chamber can be directly sampled, and the state of plastic fluidity, etc. of the excavated soil filled in the chamber can be checked. can be quickly grasped.

In addition, in the present invention, by providing the configuration described in claims 10 and 11, it is possible to grasp the state of the excavated soil filled in the chamber at a suitable timing, such as the plastic fluidity.

In addition, in the present invention, by providing the configuration according to claim 12, it is possible to accurately grasp the position where adjustment is required and to efficiently inject the additive into that position.

1 is a schematic cross-sectional view showing an example of an earth pressure type shield excavator with a sampling device according to the present invention; FIG. FIG. 2 is an enlarged side view showing the sample collecting device in FIG. 1; FIG. 4 is an enlarged partial cutaway vertical cross-sectional view of the same sample-collecting tube portion, showing a state before sample collection. (a) is a conceptual diagram showing an example of arrangement of through-holes, and (b) is a conceptual diagram showing an example of arrangement of through-holes. Fig. 3 is an enlarged side view showing another example of the same sampling device; FIG. 2 is an enlarged partial cutaway vertical cross-sectional view showing a state of sampling work of excavated soil in the earth pressure type shield construction method according to the present invention. Fig. 3 is an enlarged partial cutaway vertical cross-sectional view showing a state in which the same sample-collecting tube is removed; FIG. 4 is an enlarged partially broken longitudinal sectional view showing another example of the excavated soil sampling work in the earth pressure shield construction method according to the present invention, and is an enlarged partially broken longitudinal sectional view showing the state before sampling. Fig. 4 is an enlarged partial cutaway vertical cross-sectional view showing the state of sample collection work; Fig. 3 is an enlarged partial cutaway vertical cross-sectional view showing a state in which the same sample-collecting tube is removed; Fig. 4 is an enlarged partial cutaway vertical cross-sectional view showing a state in which the same sample-collecting tube is reattached; Fig. 4 is an enlarged partial cutaway vertical cross-sectional view showing a state when excavated soil remaining in the sample-collecting pipe is discharged;

Next, an embodiment of an earth pressure shield excavator with a sampling device according to the present invention will be described based on the embodiments shown in FIGS. 1 to 5. FIG. In the figure, reference numeral 1 denotes an earth pressure type shield excavator equipped with a sampling device, and reference numeral 2 denotes a face.

The earth pressure shield excavator and the earth pressure shield construction method include the earth pressure shield excavator and the earth pressure shield construction method, and this embodiment mainly explains the earth pressure shield excavator and the earth pressure shield construction method. do.

As shown in FIG. 1, an earth pressure shield excavator equipped with a sampling device (hereinafter referred to as an earth pressure shield excavator) 1 includes a tubular shield body 3 and a cutter head 4 disposed on the front surface of the shield body 3. , a partition 5 arranged behind the cutter head 4 , a chamber (pressure chamber) 6 formed between the cutter head 4 and the partition 5 , a drive means 7 for rotating the cutter head 4 , and a shield jack 8 . While excavating the face 2 by the cutter head 4, the shield jack 8 pushes the end faces of the segments 9, 9 . . .

This earth pressure type shield excavator 1 takes excavated soil 10 excavated by a cutter head 4 into a chamber 6, imparts plastic fluidity to the excavated soil 10 taken into the chamber 6, and excavates soil having plastic fluidity. 10 is pressed against the face 2 to excavate while applying earth pressure to the face 2, and the excavated soil 10 taken into the chamber 6 is discharged from the chamber 6 by a screw type earth removal device 11.

This earth pressure type shield excavator 1 is equipped with a measuring means (not shown) such as an earth pressure gauge for measuring the earth pressure inside the chamber 6, and the earth pressure inside the chamber 6 can be measured at any time by this measuring means. there is Note that the measuring means is not limited to the earth pressure gauge, and any means capable of detecting changes in the condition of the excavated soil 10 in the chamber 6 may be used.

Reference numeral 12 in the drawing denotes an agitating member supported behind the cutter head 4, which agitates the excavated soil 10 taken into the chamber 6 by the rotation of the cutter head 4. As shown in FIG.

Although not shown, a pipe for supplying the additive material is piped inside the rotating shaft portion of the cutter head 4, and the additive material supplied through this pipe is injected from an injection hole provided near the cutter bit. It is designed to be thrown into the chamber 6 .

The earth pressure type shield excavator 1 is also equipped with a sampling device 20 for sampling the excavated soil 10 taken into the chamber 6, and the excavated soil 10 filled in the chamber 6 is properly plasticized based on the sampled sample. It is possible to grasp whether the material has fluidity, uniformity, and water impermeability (hereinafter referred to as plastic fluidity, etc.).

As shown in FIGS. 2 and 3, the sampling device 20 includes a water stop valve 22 connected to a through hole 21 passing through the partition wall 5, and a sample collection tube 23 detachably connected to the water stop valve 22. , a pressure regulating means 24 for regulating the pressure in the sampling tube 23, and a depressurization valve 25 connected to the body of the sampling tube 23, and a negative pressure is applied to the inside of the sampling tube 23 to open the chamber. The excavated soil 10 in 6 can be pulled into the sampling tube 23 .

Although the through-holes 21 are shown in one position in the drawing for convenience, they are provided at a plurality of positions in the partition wall 5 so that the excavated soil 10 in the chamber 6 can be sampled at each position of each through-hole 21 . is preferred.

The installation positions of the through-holes 21 are set in consideration of the inner diameter of the earth pressure shield excavator 1 and the position of the stirring member 12, and are spaced apart from each other so that the condition of the excavated soil 10 distributed in the chamber 6 can be evenly investigated. For example, as shown in FIG. 4( a ), at approximately the center position of the partition wall 5 , two locations facing each other at intervals in one diametrical direction passing through the center position, It is provided at two locations opposite to each other with an interval in the diametrical direction forming a right angle with each other, and is provided at about five locations in a cross shape.

When the earth pressure type shield excavator 1 is large, as shown in FIG. It may be provided at a total of 9 locations, ie, 4 locations facing each other at intervals in the diametrical direction forming a right angle to the one diametrical direction.

The arrangement of the through-holes 21 is not limited to the embodiment shown in FIGS. 4(a) and 4(b), and the number and arrangement of the through-holes 21 can be freely set.

The water shut-off valve 22 has a structure in which two valve bodies 26, 26 made of openable and closable ball valves or the like are connected in the axial direction. A brim-shaped flange portion 27 to which the sampling tube 23 is connected is formed on the edge.

The sampling pipe 23 is formed in a cylindrical shape made of a steel pipe, a resin pipe such as vinyl chloride, or the like. Flanges 28 and 29 are integrally supported at the opening edges at both ends, and the flange 28 serves as a water stop valve. It is detachably connected to the water shutoff valve 22 by bolting it in a state of overlapping with the flange portion 27 of 22 .

The sampling pipe 23 is provided with a depressurization valve 25 on the water stop valve 22 side of the body, and the pressure in the sampling pipe 23 can be released by opening and closing the depressurization valve 25. there is

The body of the sampling tube 23 is provided with a window 30 for checking the inside, and the window 30 for checking the inside is closed by a transparent glass plate, so that the inside of the sampling tube 23 can be visually recognized through the glass plate. ing.

The interior confirmation window 30 can be provided at the end of the body on the rear side (opposite side of the water stop valve 22) so that it can be confirmed that a sufficient amount of excavated soil 10 has been taken in. desirable.

As shown in FIG. 3, the pressure adjusting means 24 is composed of a piston 31 slidably inserted into the sample-collecting tube 23 and an operating means 32 for sliding the piston 31. By sliding the piston 31, the pressure inside the sampling tube 23 can be adjusted.

That is, with the depressurization valve 25 closed, the piston 31 is slid in the withdrawal direction, that is, from the water stop valve 22 side to the other end side, thereby generating a negative pressure in the sample collection tube 23 and pushing it out. That is, the inside of the sampling pipe 23 is pressurized by sliding the piston 31 from the other end side toward the water stop valve 22 side.

The operating means 32 is composed of a hydraulic cylinder in which a rod 32a is moved in and out by hydraulic pressure, and the piston 31 fixed to the tip of the rod 32a is moved by moving the rod 32a in and out.

The operating means 32 is not limited to a hydraulic cylinder, and may be, for example, a pneumatic cylinder or an electric device for moving the rod 32a in and out, or the rod 32a may be manually moved in and out.

The operating means 32 includes a fixture 33 having a mounting flange portion 33a. there is

Incidentally, the pressure adjusting means is not limited to the above embodiment, and as shown in FIG. It may be configured by

The supply/discharge pipe 40 is configured by a hose or the like, and has a joint portion 42 having a flange portion 42a at the tip portion on the sampling pipe 23 side. and can be detachably connected by bolting or the like.

A squeeze pump is used as the pump 41, and the squeeze pump 41 is reversely operated when the insides of the sample collection tube 23 and the supply/discharge tube 40 are empty (state of only air) and the depressurization valve 25 is closed. A negative pressure is applied to the inside of the sampling tube 23 . In this embodiment, a squeeze pump is used as the pump 41, but the pump 41 is not limited to a squeeze pump as long as it has pumping and suction functions like a squeeze pump.

The squeeze pump 41 also functions as fluid pressure-feeding means for pressure-feeding a fluid 43 such as water into the sample collection tube 23. A storage tank 44 for storing the fluid 43 such as water is stored in the squeeze pump 41 and a connecting hose. A fluid 43 such as water can be pressure-fed into the sampling pipe 23 through the supply/discharge pipe 40 by connecting via 45 and rotating in the normal direction.

In the above-described embodiment, a case where a squeeze pump is used as the pump 41 has been described. Well, in that case, the fluid pumping means may be provided separately and installed so as to be switchable with the suction pump.

In addition, the earth pressure type shield excavator 1 is detachably provided with a sample collection pipe 23, and instead of the sample collection pipe 23, an additive material injection means for supplying an additive material such as mud addition material to the water stop valve 22 is provided. It is ready to connect.

Next, an earth pressure shield construction method using the earth pressure shield excavator 1 will be described. In addition, the same reference numerals are given to the same configurations as those of the above-described embodiment.

In this earth pressure shield construction method, a face 2 is excavated by a cutter head 4, an earth pressure shield excavator 1 is propelled, and excavated soil 10 excavated by the cutter head 4 is taken into a chamber 6 and taken into the chamber 6. The excavated soil 10 is agitated or added with additives to give it plastic fluidity, and the face 2 is excavated while applying earth pressure.

At that time, it is important that the excavated soil 10 filled in the chamber 6 has appropriate plastic fluidity, uniformity, and water impermeability (hereinafter referred to as plastic fluidity, etc.) in order to stabilize the face 2. The plastic fluidity of the excavated soil 10 is greatly affected by the geology and particle size distribution of the ground to be excavated, the additive used and the amount of the additive. A negative pressure is applied in 23, the excavated soil 10 in the chamber 6 is taken into the sampling tube 23, and the properties of the sampled excavated soil 10 are evaluated.

In this embodiment, the case where the pressure adjusting means 24 is composed of a piston 31 slidably inserted into the sampling tube 23 and an operating means 32 for sliding the piston 31 will be described.

Specifically, first of all, as a preliminary preparation, before starting excavation, necessary investigations such as boring tests and geological surveys are conducted, and the type and composition of additives are set based on the results of polling tests and soil vertical cross-sections. do.

In addition, the water stop valve 22 is closed, the sample collection pipe 23 is connected to the water stop valve 22, the operating means 32 such as a hydraulic cylinder is attached to the other end of the sample collection pipe 23, and the piston 31 is moved to the sample collection pipe 23. insert inside.

In the initial state, as shown in FIG. 3, the operating means 32 is actuated to slide the piston 31 in the pushing direction, and the depressurization valve 25 is closed at that position.

Next, when excavation is actually started, a predetermined earth pressure is applied to the face 2 by the excavated soil 10 filled in the chamber 6, and the collapse of the face 2 due to the stress release of the natural ground is pushed. Excavation work and promotion work are repeated in order to excavate (excavation work).

The excavated soil 10 is taken into the chamber 6, and after the chamber 6 is filled with the excavated soil 10, substantially the same amount of the newly taken-in excavated soil 10 is discharged into the screw-type earth removing device 11. The excavated soil 10 in the chamber 6 is replaced while maintaining the soil pressure in the chamber 6 (excavation work).

On the other hand, the excavated soil 10 taken into the chamber 6 is added with an additive (additional material, etc.), and is stirred by the stirring members 12, 12 as the cutter head 4 rotates. (Plastic fluidity adjustment work).

During excavation, the soil pressure of the excavated soil 10 in the chamber 6 is measured by measuring means such as a soil pressure gauge at any time, and when the soil pressure deviates from the reference range, it is detected. .

Then, while simultaneously performing the excavation work, the soil removal work, and the plastic fluidity adjustment work, the excavated soil 10 in the chamber 6 is taken into the sample collection pipe 23 at a predetermined timing, and a sample of the excavated soil 10 is collected, It is confirmed whether the excavated soil 10 has appropriate plastic fluidity and the like.

The timing of sampling is not particularly limited, but for example, when excavation is continued for a certain period of time, the excavated soil 10 in the chamber 6 is replaced and the plastic fluidity is adjusted, and when an abnormal value is measured by the measuring means. It is preferable to carry out when reaching a range where the geological features of the ground to be excavated, which has been investigated in advance, is expected to change.

For sample collection, first, the water stop valve 22 is opened while the depressurization valve 25 is closed, and the inside of the chamber 6 and the inside of the sample collection pipe 23 are communicated.

Next, as shown in FIG. 6, when the piston 31 is slid from the water stop valve 22 side to the other end side, a negative pressure is generated in the sampling tube 23, and the chamber is closed as the piston 31 slides. Excavated soil 10 in 6 is taken into sampling tube 23 .

At that time, if gravel gets caught in the sample-collecting tube 23 and it becomes difficult to collect the excavated soil 10, the piston 31 is slid in the push-out direction, and the gravel in the sample-collecting tube 23 is removed by the piston 31. 6, and after that, the piston 31 is again slid in the withdrawal direction to collect a sample.

Then, the piston 31 is slid to a predetermined position, the excavated soil 10 is taken up to a predetermined position in the sampling tube 23, and the sample of the excavated soil 10 is filled in the sampling tube 23 through the window 30 for checking the interior. to confirm.

Next, the stop valve 22 is closed, and the depressurization valve 25 connected to the body of the sampling tube 23 is opened to release the pressure inside the sampling tube 23 .

When the pressure inside the sampling tube 23 is completely released, the pressure relief valve 25 is closed, and as shown in FIG. Then, the piston 31 is pulled out from inside the sampling tube 23 .

Then, the sample collection pipe 23 attached to the water stop valve 22 via the flange portion 28 is removed, the sample is collected, a slump test or the like is performed, and the excavated soil 10 in the chamber 6 has appropriate plastic fluidity, uniformity, Evaluate whether it has water impermeability, etc. Reference numeral 34 in the drawing denotes a cover member that closes the openings at both ends of the sample collection tube 23 .

Then, the sampling and evaluation described above are performed for each position of the plurality of through-holes 21, and the plastic fluidity and the like are evaluated at each position. If the earth pressure type shield excavator 1 has a large diameter, it is desirable to provide a foothold (not shown) for safety when sampling from the through hole 21 located above.

As a result of the evaluation, if there is no problem, excavation is continued, and samples are taken at each predetermined timing.

On the other hand, as a result of the evaluation, if it is determined that any of the samples corresponding to the position of each through-hole 21 does not meet the criteria such as plastic fluidity, add to the water stop valve 22 of the corresponding through-hole 21 A material injection means is attached, and an additive material such as a mud additive is introduced into the chamber 6 through the through hole 21 to adjust the plastic fluidity and the like. The injection amount and composition of the additive are determined based on the results of a slump test or the like.

In this way, it is determined whether or not the criteria such as plastic fluidity are satisfied for each position of the through-hole 21, and the additive material is introduced through the through-hole 21 at the position determined not to satisfy the criteria. It is possible to accurately grasp the position where the additive is required and to efficiently inject the additive into that position.

Then, after a series of sampling, evaluation, and adjustment of plastic fluidity, etc., the sampling pipe 23 is again connected to the water stop valve 22 provided in each through hole 21, and the above-described operation is performed at predetermined timings. A series of sample collection and adjustments such as plastic fluidity are carried out.

In the above embodiment, the pressure adjusting means 24 is composed of the piston 31 slidably inserted into the sampling tube 23 and the operating means 32 for sliding the piston 31. A sample collection operation in the case where the pressure adjusting means 24 is composed of a supply/discharge pipe 40 connected to the sample collection pipe 23 and a pump 41 connected via the supply/discharge pipe 40 will be described below. In addition, the same reference numerals are given to the same configurations as those of the above-described embodiment.

First, as a preparation, the water stop valve 22 is closed, the sample collection pipe 23 is connected to the water stop valve 22, one end of the supply/discharge pipe 40 is connected to the other end of the sample collection pipe 23, and the other end is connected to the other end of the sample collection pipe 23. It is connected to a pump 41 consisting of a squeeze pump.

In the initial state, as shown in FIG. 8, the sample collection pipe 23 and the supply/discharge pipe 40 are not filled with fluid, and the depressurization valve 25 is closed.

Sampling is performed at the same timing as in the above-described embodiment. First, the shutoff valve 22 is opened while the depressurization valve 25 is closed, and the inside of the chamber 6 and the inside of the sampling pipe 23 are communicated.

Next, as shown in FIG. 9, the squeeze pump 41 is reversely operated to suck the air in the sample collection pipe 23 and the supply/discharge pipe 40, apply a negative pressure to the sample collection pipe 23, and The excavated soil 10 is drawn inside.

Then, the excavated soil 10 is sucked up to a predetermined position in the sampling tube 23 by suction by the squeeze pump 41 , and it is confirmed through the window 30 for checking the interior that the sample of the excavated soil 10 is filled in the sampling tube 23 .

Next, the stop valve 22 is closed, and the depressurization valve 25 connected to the body of the sampling tube 23 is opened to release the pressure inside the sampling tube 23 .

After the pressure in the sampling tube 23 is completely released, the pressure relief valve 25 is closed, and as shown in FIG.

Then, the sampling pipe 23 attached to the water stop valve 22 via the flange portion 28 is removed to collect the sample, and a slump test or the like is performed. , uniformity, impermeability, etc.

Then, the sampling and evaluation described above are performed for each position of the plurality of through-holes 21 to evaluate the plastic fluidity and the like at each position.

As a result of the evaluation, if there is no problem, excavation is continued, and samples are taken at each of the predetermined timings.

On the other hand, as a result of the evaluation, if it is determined that any of the samples corresponding to the position of each through-hole 21 does not meet the criteria such as plastic fluidity, add to the water stop valve 22 of the corresponding through-hole 21 A material injection means is attached, and an additive material such as a mud additive is injected through the through hole 21 to adjust the plastic fluidity and the like.

Then, after a series of sampling, evaluation, and adjustment of plastic fluidity, etc., as shown in FIG. A supply/discharge pipe 40 is attached to the sample collection pipe 23 . Reference numeral 10a in the figure denotes excavated soil remaining in the sampling tube 23 due to cleaning leakage or the like after the evaluation.

Also, the squeeze pump 41 is connected to a storage tank 44 in which a fluid 43 such as water is stored.

Next, with the water stop valve 22 closed, the depressurization valve 25 is opened, and the squeeze pump 41 is operated in the normal direction to supply the fluid 43 such as water sucked from the storage tank 44 to the sample collection pipe 23 . Pump through drain 40 .

When the fluid 43 such as water comes out from the depressurization valve 25, the squeeze pump 41 is temporarily stopped and then the depressurization valve 25 is closed.

Next, as shown in FIG. 12, the water shut-off valve 22 is opened, the squeeze pump 41 is restarted, water such as fluid is pumped again, and the excavated soil 10a remaining in the sampling pipe 23 is removed by the water pressure. It is discharged to the chamber 6 side.

If the discharge pressure at this time is weaker than the soil water pressure in the chamber 6, the excavated soil 10 in the chamber 6 will conversely flow into the sampling pipe 23, so that the excavated soil 10 is pumped with a force stronger than that pressure.

After the excavated soil 10 remaining in the sampling pipe 23 is discharged, the water shut-off valve 22 is closed again, and thereafter, the above-described series of sampling to adjustment of plastic fluidity and the like are performed at predetermined timings. conduct.

In the earth pressure shield construction method configured in this manner, the excavated soil 10 is directly sampled from a predetermined position in the chamber 6, so the condition of the excavated soil 10 in the chamber 6 can be evaluated and grasped in real time.

At this time, in this earth pressure shield construction method, since the earth and sand are drawn into the sampling pipe 23 by applying negative pressure to the sampling pipe 23, unlike the conventional case of using a screw for sampling, a stirrer or the like is used. Samples can be taken during drilling without the need to worry about interference with the

1 Earth Pressure Shield Excavator with Sampling Device 2 Face 3 Shield Main Body 4 Cutter Head 5 Partition Wall 6 Chamber 7 Driving Means 8 Shield Jack 9 Segment 10 Excavated Soil 11 Screw Type Unloading Device 12 Stirring Member 20 Sampling Device 21 Through Hole 22 Water stop valve 23 Sampling pipe 24 Pressure adjusting means 25 Depressurization valve 26 Valve body 27 Flange 28 Flange 29 Flange 30 Internal confirmation window 31 Piston 32 Operating means 33 Fixing tool 40 Supply/discharge pipe 41 Pump (squeeze pump)
42 joint part 43 fluid 44 storage tank 45 connection hose

Claims (12)

An earth pressure type shield excavator equipped with a sampling device in which excavated soil taken into a chamber formed between a cutter head and a bulkhead is made to have plastic fluidity, and excavation is performed while applying earth pressure to the face. ,
a through-hole penetrating through the partition wall, a water stop valve connected to the through-hole, a sample collection tube detachably connected to the water stop valve, and pressure control means for applying negative pressure to the inside of the sample collection tube. and a depressurization valve connected to the body of the sampling pipe so that excavated soil in the chamber can be drawn into the sampling pipe. machine. 2. The earth pressure shield excavator with a sampling device according to claim 1, wherein said pressure adjusting means can pressurize the inside of said sampling pipe. 3. An earth pressure shield with a sample-collecting device according to claim 1, wherein said pressure adjusting means comprises a piston slidably inserted into said sample-collecting pipe and an operating means for sliding said piston. Excavator. 3. The soil pressure type with a sample collecting device according to claim 1, wherein said pressure adjusting means comprises a supply/discharge pipe connected to said sample collection pipe, and a pump connected via said supply/discharge pipe. shield excavator. 5. An earth pressure shield excavator with a sample collecting device according to claim 4, further comprising a fluid pumping means for pumping a fluid into said sample collecting pipe through said supply and discharge pipe. The earth pressure shield excavator with a sample collecting device according to any one of claims 1 to 5, wherein the sample collecting pipe has a window for checking the inside in the body portion. An earth pressure shield with a sample collecting device according to any one of claims 1 to 6, wherein a plurality of said through holes are provided so that excavated soil in said chamber can be pulled into said sample collecting pipe at each position of each through hole. Excavator. 8. An earth pressure shield excavator with a sample collecting device according to claim 7, wherein said sample collecting pipe is detachably provided, and additive material injection means can be connected to said water stop valve in place of said sample collecting pipe. In the earth pressure shield construction method, excavated soil taken into a chamber formed between a cutter head and a partition wall is made to have plastic fluidity and excavation is performed while applying earth pressure to the face,
Using a water stop valve connected to a through hole penetrating the partition,
During excavation, a negative pressure is applied to a sampling pipe connected to the water stop valve, the excavated soil in the chamber is taken into the sampling pipe, and the properties of the collected excavated soil are evaluated. Earth pressure type shield construction method. 10. The earth pressure shield construction method according to claim 9, wherein the condition of the excavated soil in the chamber during excavation is measured by a measuring means at any time, and the excavated soil is sampled when an abnormal value is measured by the measuring means. 10. The earth pressure shield construction method according to claim 9, wherein the geology of the ground to be excavated is surveyed in advance, and the excavated soil is collected in a range where the geology is expected to change as a result of the survey. providing a plurality of through-holes, and evaluating the plastic flowability of the excavated soil taken into the sample-collecting pipe at each position of each through-hole;
In place of the sampling pipe that took in the excavated soil at the position where the plastic fluidity was determined to be insufficient, an additive injection means was connected to the water stop valve, and the plastic fluidity was determined to be insufficient. The earth pressure shield construction method according to any one of claims 9 to 11, wherein the additive material is injected into the excavated soil at the position where the earth pressure shield is formed.

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