JP6386844B2 - Tremy tube device and underwater casting method for solidified soil - Google Patents

Description

  The present invention relates to a tremy tube device and a submerged placement method for solidified soil, and more specifically, a tremy tube device that can be placed in water with high quality by preventing underwater separation of the solidified soil, and a submerged placement of solidified soil. It is about the method.

  In recent years, it is a solidified soil produced by adding and mixing solidification materials using construction-generated soil and dredged sand at ports and airports, etc., and solidified treatment soil produced by adding and mixing lightening materials. Some lightweight mixed soil (SuperGeoMaterial) has been used. This lightweight mixed treated soil is manufactured by mixing dredged soil, seawater, cement and air bubbles, for example, and thus is lighter than a general ground material. Further, there is an advantage that the density and strength can be controlled by changing the mixing ratio of the materials. Furthermore, it is possible to reuse soft construction soil and dredged soil with a high water content, and because it has high fluidity, it is not necessary to compact just by pumping when placing. is there.

  A tremy tube may be used when such solidified soil is placed in water such as the sea. When placing the solidified soil, the faster the flow rate when it is thrown in, the easier it is to entrain seawater and the easier it is to separate in water. When this underwater separation occurs, there is a problem that the quality of the solidified soil placed in the water is lowered, for example, the density is changed or the strength is lowered.

  Various devices and methods for preventing underwater separation of materials to be placed in water have been proposed (see, for example, Patent Document 1). In Patent Document 1, it is proposed to provide an on-off valve portion at the most advanced discharge port of a pressure feed pipe connected to a pump car. In this proposal, the on-off valve portion is opened only when placing the underwater concrete so that unnecessary water and air do not enter the pressure feed pipe, thereby preventing the underwater concrete from being separated from the water. In Patent Document 2, it is proposed to provide a guide plate around the discharge port of the tremy tube so as to surround the discharge port. In this proposal, the slurry is driven to the bottom of the water along the guide plate while suppressing the bounce of the slurry to be driven from the bottom of the water by the guide plate. However, since these conventional apparatuses and methods are not intended for placing solidified soil, it is not possible to reduce the placement speed sufficiently to prevent such separation of the treated soil in water. Therefore, it was difficult to place the solidified soil in water with high quality.

Japanese Utility Model Publication No. 7-12532 JP-A-63-304876

  An object of the present invention is to provide a tremy tube device that can be placed in water with high quality by preventing the separation of the solidified soil in water, and an underwater placing method thereof.

In order to achieve the above object, a tremey tube device of the present invention comprises a tremy tube, an opening / closing member that opens and closes a lower end opening of the tremy tube, and a receiving part disposed at the lower end of the tremey tube, A receiving plate whose portion faces the lower end of the tremy tube, and a cylindrical plate that is erected on the receiving plate and arranged on the outer peripheral side of the peripheral wall of the lower end portion of the tremy tube with a space from the peripheral wall The lower end opening is closed by the opening and closing member before the solidified soil is supplied to the internal space of the tremy tube, and the internal space is filled with a predetermined amount of the solidified soil. It is set so that the opening by the opening / closing member is later released and opened .

Water hitting設方method of solidification soil of the present invention, the solidification soil predetermined amount in the internal space in the state where the lower end opening was closed by the closing member of the tremie tube constituting the above tremie pipe system after filling, by releasing the closing of the lower end opening by the closing member of the tremie tube device arranged lower ends into the water, outflow of the solidification soil inside the receiving portion through the lower end opening The solidified soil discharged to the inside of the receiving part is continuously overflowed from the upper end part of the receiving part and placed in water while the tremy tube device is moved upward.

  According to the present invention, a predetermined amount of solidified soil filled by being pumped into the inner space of the tremy tube is released from the opening of the lower end portion of the tremy tube by the opening and closing member. By letting it flow into the receiving part, the solidified soil that falls in the inner space of the tremy tube by the feed pressure and its own weight is temporarily received by the receiving part. And, while moving the tremely pipe device upward, the solidified soil temporarily received by the receiving part is continuously overflowed from the upper end of the receiving part and placed in the water, so that the placing speed is greatly reduced. Can do. Thereby, even if it is the solidified soil which is easy to entrain water or to separate in water, it becomes possible to place it in water without causing underwater separation. Accordingly, in the solidified soil placed in water, problems such as a large change in density and a decrease in strength can be avoided, and high quality can be ensured.

It is a longitudinal cross-sectional view which illustrates embodiment of the tremy tube apparatus of this invention. It is explanatory drawing which illustrates the inside of the receiving part of FIG. It is AA sectional drawing of FIG. It is a longitudinal cross-sectional view which illustrates the state which filled the interior space of the tremy pipe | tube of FIG. 1 with the lightweight mixing process soil. It is explanatory drawing which illustrates the inside of the receiving part of FIG. It is explanatory drawing which illustrates the state which shrunk the opening-and-closing member of FIG. It is explanatory drawing which illustrates the state which has overflowed the lightweight mixing process soil from the receiving part of FIG. It is explanatory drawing which illustrates the process in which the lightweight mixing process soil is laid in water, moving a tremy pipe device upward. It is a graph which shows the relationship between the density change of a lightweight mixing process soil, and a flow value. It is a graph which shows the relationship between the strength ratio of lightweight mixing process soil, and a flow value. It is a graph which shows the relationship between the water content ratio variation | change_quantity of a lightweight mixing process soil, and a flow value. It is a graph which shows the relationship between SS (turbidity) and flow value of lightweight mixed processing soil. It is a graph which shows the relationship between pH of a lightweight mixing process soil, and a flow value.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the Tremy tube device and the solidified soil underwater pouring method of the present invention will be described based on the embodiment shown in the drawings, taking as an example the case of placing a light mixed treated soil.

  As illustrated in FIGS. 1 to 3, the embodiment of the tremy tube device 1 of the present invention includes a tremy tube 2, an opening / closing member 5 that opens and closes a lower end opening 2 a of the tremy tube 2, and a lower end portion of the tremy tube 2. And a receiving portion 4 to be arranged. The tremy tube 2 is configured by connecting a plurality of divided tubes 3. An appropriate number of dividing pipes 3 are connected so as to have an appropriate length according to the depth of water in which the lightweight mixed soil S is placed.

  In this embodiment, a straight cylindrical steel pipe is used for the tremy pipe 2. The size of the tremy tube 2 is, for example, an inner diameter of about 0.1 m to 0.4 m, a peripheral wall thickness of 2 mm to 10 mm, and a total length of about 2.5 m to 25 m. A suspension wire 9 is attached to the upper end portion of the tremy tube 2, and the tremy tube device 1 can be moved up and down by being suspended by a crane or the like via the suspension wire 9.

  A U-shaped bent tube 7 bent downward is continuously provided at the upper end portion of the tremy tube 2. The curved pipe 7 is provided with an on-off valve 7b for communicating and blocking the curved pipe 7. A supply pipe 8 that supplies the light-mixed mixed soil S pumped from a supply source is connected to a position in the longitudinal direction of the tremy pipe 2.

  The opening / closing member 5 of this embodiment is a rubber hollow body, and is connected to a pipe connected to a fluid supply source such as air. By opening / closing the fluid supplied from the fluid supply source to / from the opening / closing member 5, the opening / closing member 5 expands and contracts. When the opening / closing member 5 expands and closes the lower end opening 2a of the tremmy tube 2, the lower end opening 2a is closed, and when the opening and closing is released, the lower end opening 2a is opened. Yes. As long as the opening / closing member 5 can open and close the lower end opening 2a, other configurations can be adopted.

  The receiving part 4 is comprised by the receiving plate 4a facing the lower end (lower end part opening 2a) of the tremy tube 2, and the cylindrical board 4b standingly arranged on the receiving plate 4a. The cylindrical plate 4b is disposed on the outer peripheral side of the peripheral wall at the lower end portion of the tremy tube 2 with a space from the peripheral wall. That is, the receiving part 4 of the bottomed cylindrical body is installed so as to cover the lower end part of the tremy tube 2.

  In this embodiment, the bottomed cylindrical receiving portion 4 is installed so as to cover the lower end portion of the tremmy tube 2, and the casing 6 installed on the receiving plate 4 a is connected to the lower end portion opening 2 a of the tremy tube 2. It is installed. The casing 6 has, for example, a cylindrical shape, and the opening / closing member 5 is covered with the casing 6 and disposed inside the casing 6.

  A through hole having the same diameter as the lower end opening 2 a is formed on the upper surface of the casing 6, and the internal space of the tremy tube 2 and the inside of the casing 6 communicate with each other through the through hole. A plurality of discharge ports 6 a are formed in the circumferential wall of the casing 6 at intervals in the circumferential direction. When the opening / closing member 5 opens the lower end opening 2a of the tremy tube 2, the internal space of the tremy tube 2 and the space between the peripheral wall of the casing 6 and the cylindrical plate 4b are discharged through the inside of the casing 6. It is the structure which communicates through the exit 6a. The total opening area of the discharge port 6a is set to about 20% to 50% of the area of the outer peripheral wall of the casing 6, for example.

  Next, a method for placing the lightweight mixed soil S in water using the tremy tube device 1 will be described.

  The lightly mixed treated soil S to be placed in water is manufactured, for example, at a plant constructed near the placement site, and is pumped to the tremy pipe device 1 through the supply pipe 8 by a pump or the like. If an example of the manufacturing process of the lightweight mixed processing soil S is demonstrated, first, the raw material soil unearthed from the soil carrier will be screened with a vibration sieve, and will be sent to a mud tank. In the mud tank, water is adjusted so that the raw material soil has a predetermined density. Next, the lightly mixed treated soil S is produced by mixing and stirring the adjusted soil, cement, and air bubbles in a mixing tank at a predetermined ratio. The bubbles are produced, for example, by diluting a foaming agent with seawater and foaming. In addition, the manufacturing method of the solidification processing soil which does not mix a bubble is the same as the manufacturing process of the lightweight mixing processing soil S except that there is no manufacturing process and mixing process of a bubble.

In the tremy tube device 1, the opening / closing member 5 is expanded to close the lower end opening of the tremy tube 2, and the opening / closing valve 7 b is opened to communicate the internal space and the external space of the tremy tube 2 through the opening 7 a of the curved tube 7. To a state to do. Next, the lightly mixed treated soil S is supplied to the inner space of the tremy pipe 2 through the supply pipe 8 and filled. After confirming that the supplied lightweight mixed soil S has flowed out of the opening 7a of the curved pipe 7, the on-off valve 7b is closed. At this stage, as illustrated in FIG. 4, the lightweight mixed soil S is filled in the entire internal space of the tremy tube 2.

The tremy tube device 1 positions the lower end of the tremy tube 2 in water and positions the receiving plate 4a at a height of about 10 cm above the water bottom. Since the opening / closing member 5 expands to close the lower end opening 2a as illustrated in FIG. 5, the lower end opening 2a is opened by contracting the opening / closing member 5 as illustrated in FIG. As a result, a predetermined amount of the light-mixed soil S filled in the internal space of the tremy tube 2 flows out of the casing 6 from the lower end opening 2a.

  As illustrated in FIG. 7, the lightly mixed treated soil S that has flowed into the casing 6 flows into the space between the peripheral wall of the casing 6 and the peripheral wall of the tremmy pipe 2 and the cylindrical plate 4 b through the discharge port 6 a. . Next, the lightweight mixed soil S that has flowed into this space continuously overflows from the upper end of the receiving portion 4. Since the lightweight mixed treated soil S overflowed from the upper end of the receiving portion 4 is placed in the water and accumulated on the bottom of the water as illustrated in FIG. 8, the lightweight mixed treated soil S is driven while the tremy pipe device 1 is moved upward. Set up. For example, the receiving plate 4a is always maintained at a position 0.5 m to 1 m lower than the top end of the light-mixed soil S deposited on the bottom of the water, and the upper end of the receiving portion 4 is placed in the light-mixed soil S. To do.

  According to the present invention, the lightweight mixed treated soil S is caused to flow into the receiving portion 4 through the lower end opening 2a, and the lightweight mixed treated soil S pumped through the inner space of the tremy tube 2 is temporarily received by the receiving portion 4. Take it. And while moving the tremy pipe device 1 upward, the lightweight mixed treated soil S temporarily received by the receiving portion 4 is continuously overflowed from the upper end portion of the receiving portion 4 and placed in the water. The speed of placing S into water can be greatly reduced. By adopting such an overflowing structure, it becomes possible to secure a wide discharge area of the lightweight mixed treated soil S, and the lightweight mixed treated soil S can be placed in water with a sufficiently low flow rate. it can.

  Thereby, even if it is the lightweight mixed processing soil S which is easy to carry out seawater and is separable in water compared with a general ground material, the entrainment of seawater is suppressed and it is placed in water without causing underwater separation. Can do. Along with this, in the light-mixed mixed soil S placed in water, problems such as a density change that is excessive or a decrease in strength are avoided, and high quality can be ensured. . For example, it can be avoided that the density of the light-mixed mixed soil S that has been laid becomes higher than expected and the light-weight merit of the light-mixed mixed soil S is impaired.

  In this embodiment, the lightweight mixed soil S filled in the internal space of the tremmy pipe 2 is temporarily stored in the casing 6 and then discharged to the internal space of the receiving portion 4 through the discharge port 6a. . For this reason, the resistance acting on the flowing lightweight mixed treated soil S is further increased, and it is more advantageous to reduce the placement speed of the lightweight mixed treated soil S to prevent underwater separation.

  The inner diameter of the cylindrical plate 4b is, for example, 1.5 to 10 times the inner diameter of the tremy tube 2, and the height of the cylindrical plate 4b is, for example, 200 mm to 800 mm. Accordingly, an appropriate amount of the light-mixed treated soil S can be temporarily received by the receiving portion 4, so that it is preferable for setting the speed so that the light-mixed treated soil S is not separated in water. Further, the inner diameter of the casing 6 is, for example, 1.5 to 5 times the inner diameter of the tremy tube 2, and the height of the casing 6 is, for example, 200 mm to 400 mm. Thereby, the magnitude | size of the resistance added to the light weight mixing process soil S which flows becomes more appropriate, and it becomes possible to perform smooth placement, preventing the light mixing process soil S from being separated in water.

  Note that the present invention is not limited to the lightweight mixed soil S, but can be applied to other solidified soil and various materials that are easily separated in water.

  Light-weight mixed treated soil S was produced by mixing and stirring clay, seawater, cement, and air bubbles at a predetermined ratio. At that time, five types of lightweight mixed-treated soils S with different flow values were produced by changing only the blending ratio of seawater. (Revised version) "(July 2008, edited by Coastal Technology Research Center) Annex-2, the water separation resistance test method specified in Appendix-2, density change, strength ratio, moisture content change amount, Turbidity (SS) and pH were measured. The results are shown in FIGS. In each measurement, the driving speed was set to three types: a low flow rate (10 cm / sec), a medium flow rate (40 cm / sec), and a high flow rate (70 cm / sec).

  From the result of FIG. 9, when the flow value exceeds 25 cm at a medium flow rate and exceeds 20 cm at a high flow rate, the value obtained by subtracting the air density from the water density greatly increases, and the bubbles in the lightly mixed soil S are separated. It turns out that it decreases significantly by doing. It can be seen that the density change is very small at low flow rates. From the results shown in FIG. 10, when the flow value exceeds 25 cm at a medium flow rate, and the flow value exceeds 20 cm at a high flow rate, the strength ratio is significantly reduced, and a large amount of water is caught in the mixed lightweight treated soil S at the time of placing. I understand. It can be seen that the intensity ratio changes very little at low flow rates. From the result of FIG. 11, when the flow value exceeds 25 cm at a medium flow rate and the flow value exceeds 20 cm at a high flow rate, the amount of water content change greatly increases, and a large amount of water is caught in the mixed lightweight treated soil S at the time of placing. I understand that. It can be seen that the moisture content change is very small at low flow rates. From the results of FIG. 12, it can be seen that when the flow value exceeds 25 cm at a medium flow rate, and the flow value exceeds 20 cm at a high flow rate, SS (turbidity) increases significantly, and turbidity becomes excessive at the time of placement. It can be seen that SS is extremely small at a low flow rate. From the results of FIG. 13, it can be seen that when the flow value exceeds 25 cm at the medium flow rate and the flow value exceeds 20 cm at the high flow rate, the pH greatly increases, and the cement diffuses and is easily separated in water at the time of placing. It can be seen that the change in pH is very small at low flow rates. From the above results, it can be seen that the mixed lightweight treated soil S can be placed in water with high quality without causing separation in water even when the flow value is large by sufficiently slowing the placing speed.

Next, the above light-mixed treated soil S (flow value of about 27 cm) was placed in water using an apparatus similar to the Tremy tube apparatus illustrated in FIGS. The specifications of the Tremy tube device are as follows.
The inner diameter of the treme tube was 250 mm, the inner diameter of the receiving plate of the receiving portion was 1276 mm, the height of the cylindrical plate was 500 mm, the inner diameter of the casing was 800 mm, the height was 250 mm, and the total area of the discharge port was 1.2 m ² . As a result, although the flow velocity of the light mixed treated soil S in the inner space of the tremy pipe was about 180 cm / sec, the discharge speed from the discharge port was reduced to 10 cm / sec or less, and the light mixed treated soil S was almost completely submerged in water. It was confirmed that it could be placed on the bottom of the water without separation.

DESCRIPTION OF SYMBOLS 1 Tremy tube apparatus 2 Tremy tube 2a Lower end opening 3 Divided tube 4 Receiving portion 4a Receiving plate 4b Cylindrical plate 5 Opening and closing member 6 Casing 6a Discharge port 7 Curved tube 7a Opening 7b Opening and closing valve 8 Supply tube 9 Hanging wire S soil

Claims (5)

A tremmy tube, an opening / closing member that opens and closes a lower end opening of the tremmy tube, and a receiving portion that is disposed at the lower end of the tremy tube, the receiving portion facing the lower end of the tremy tube, on the outer peripheral side of the peripheral wall of the lower end of the tremie tube is erected on the receiving plate, formed of a cylindrical plate and which are spaced peripheral wall and spacing, the lower end opening, the tremie A setting that is closed by the opening and closing member before the solidified soil is supplied to the internal space of the pipe, and that the opening by the opening and closing member is released after the internal space is filled with a predetermined amount of the solidified soil. tremie tube apparatus characterized by being turned.   A casing is continuously provided at a lower end opening of the tremy tube, the opening / closing member is covered with the casing and disposed inside the casing, a discharge port is formed on a peripheral wall of the casing, and the opening / closing member is 2. The internal space of the tremmy tube and the space between the peripheral wall of the casing and the cylindrical plate communicate with each other through the discharge port by opening the lower end opening of the tremy tube. The tremy tube device described.   2. The opening and closing member expands and contracts by putting a fluid into and out of the inside, closes a lower end opening of the tremy tube when expanded, and opens a lower end opening of the tremy tube when contracted. Or the tremy tube device according to 2.   The tremme according to any one of claims 1 to 3, wherein a curved pipe bent downward is continuously provided at an upper end portion of the tremy pipe, and an on-off valve for connecting and blocking the curved pipe is provided. Tube equipment. After filling a predetermined amount of the solidifying treated soil in the internal space in a state where the lower end opening of the tremie tube was closed by the closing member constituting the tremie tube apparatus according to claim 1 , by releasing the closing of the lower end opening by the closing member of the tremie tube device arranged lower end portion in water, the solidification soil drained inside the receiving portion through the lower end opening, the tremie Submerging the solidified soil, wherein the solidified soil discharged to the inside of the receiving portion is continuously overflowed from the upper end of the receiving portion and placed in water while moving the pipe device upward. Installation method.

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