JP2018178471A - Caisson and method for settling caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caisson capable of settling a caisson with a simple structure even in a ground with a large N value, and a method for settling a caisson.SOLUTION: An injection hole 15a capable of injecting the high pressure fluid toward a ground G is provided on an inner peripheral surface 13b of a caisson cutting edge 13 disposed at a lower end of a caisson 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a caisson and a method of sinking a caisson.

  Conventionally, in order to sink the caisson body in the open caisson method, the ground below the cutting edge at the lower end of the caisson body is sunk by excavating the ground. Further, in the case of a ground having a large N value (for example, an N value of 10 or more in the case of cohesive soil), the caisson body is sunk by excavating the ground using a stab.

  In Patent Document 1, as a method of sinking the caisson body (sinking body) by the caisson method, the sinking body is sunk by excavating and press-fitting the cutting edge fixed to the sunking body via the jack with a vibrator. The method is described.

Japanese Patent Application Publication No. 05-118043

  However, in the conventional caisson method, it may be difficult to sink the caisson body on a ground having a particularly large N value. In addition, according to the method disclosed in Patent Document 1 in which drilling and pressing are performed while vibrating the cutting edge, sufficient rigidity and durability can be obtained because a plurality of divided cutting edges are provided to vibrate or pressurize each block. Had to be provided with a complex structure.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a caisson and a method of sinking a caisson that can be efficiently sunk with a simple structure even on a ground having a large N value.

  In order to achieve the above object, a caisson according to the present invention is a caisson having a caisson blade port disposed at a lower end, and a jet capable of injecting high pressure fluid toward the ground on the inner peripheral surface of the caisson blade port. It is characterized in that a hole is provided.

  In the caisson according to the present invention, since the injection hole capable of injecting high pressure fluid toward the ground is provided on the inner circumferential surface of the caisson blade port, even if there is a ground with a large N value below the caisson blade port, It can be easily crushed by injecting high pressure fluid to the ground. As a result, excavation of the ground can be carried out efficiently and reliably, and settlement of the caisson can be suitably promoted.

  At that time, since the injection holes can inject the high pressure fluid inward, the flow generated by the high pressure fluid, the soil on the ground ground, etc. are guided to the inside of the caisson. Thereby, the influence on the ground around the caisson can be suppressed, and the settlement of the caisson can be efficiently promoted.

Furthermore, it can implement | achieve with the simple structure which provides a predetermined | prescribed injection hole in a caisson blade port, and only supplies a high pressure fluid.
Therefore, it is possible to provide a caisson that can be efficiently sunk with a simple structure even on a ground having a large N value.

The caisson according to the present invention is characterized by comprising an ultrasonic measurement device capable of measuring the shape of the ground.
In the present invention, by providing the ultrasonic measuring device capable of measuring the shape of the ground, the shape of the ground can be easily measured during or after the excavation. Moreover, as a result of measuring the shape of the ground, it is possible to determine the presence or absence of the left digging portion of the ground. When there is a digging remaining portion in the ground, it is possible to crush and dig only the ground at the relevant location by injecting a high pressure fluid to the digging remaining portion. As a result, the caisson can be sunk efficiently and reliably.

The caisson according to the present invention is characterized in that a plurality of the injection holes are provided along the cutting edge of the caisson blade port, and an injection adjustment unit is provided for adjusting the injection state of the high pressure fluid for each of the partial injection holes. And
In the present invention, the injection adjustment unit can adjust the injection state of the high-pressure fluid for each of the injection holes of the plurality of injection holes. For this reason, if a portion or the like with an uneven shape is generated on the ground below the caisson blade mouth, the injection state is locally increased by, for example, increasing or decreasing the flow rate or flow velocity of high pressure fluid injected from the injection holes corresponding to each portion. By adjusting, the caisson can be sunk more reliably and evenly.

  In order to achieve the above object, the method of sinking a caisson according to the present invention comprises setting a caisson blade port of the caisson on a ground and excavating a ground inside and below the caisson blade port to sink the caisson. In the method, the ground is broken and excavated by injecting high-pressure fluid from the injection holes provided on the inner peripheral surface of the caisson blade port toward the ground inside and below the caisson blade port. Is characterized in that it comprises the step of sinking the

  According to the method of settling a caisson of the present invention, the ground can be broken and the excavation can be advanced by injecting high-pressure fluid from the inner circumferential surface of the caisson tip toward the ground. As a result, the settlement of the caisson can be promoted efficiently. Further, by injecting the high-pressure fluid, even the ground having a large N value can be ground by crushing the ground below the caisson blade opening, and the caisson settlement can be suitably promoted.

At that time, in order to spray the high pressure fluid inward to break the ground, the flow generated by the high pressure fluid, the soil of the broken ground, etc. are guided to the inside of the caisson. As a result, the influence on the ground around the caisson can be minimized, and the settlement of the caisson can be efficiently promoted.
Therefore, it is possible to provide a method of sinking a caisson that can sink efficiently with a simple structure even in a ground having a large N value.

In the method of sinking a caisson according to the present invention, the step of measuring the shape of the ground to determine the presence or absence of the digging left portion of the ground and the digging left portion of the ground when there is the digged left portion of the ground The method is characterized in that the high-pressure fluid is jetted to crush and excavate the undigged portion of the ground.
In the present invention, since the shape of the ground is measured to determine the existence of the digging remaining portion of the ground and the high pressure fluid is jetted to the digging remaining portion to crush the ground and excavate, it is possible to sink the caisson evenly. .

  According to the caisson and the caisson settlement method of the present invention, it is possible to provide a caisson and the caisson settlement method that can be efficiently settled with a simple structure even in the ground having a large N value.

It is a longitudinal section of a caisson provided with a caisson blade port concerning an embodiment of the present invention. It is a figure explaining the sinking method of the caisson which concerns on embodiment of this invention, and is a longitudinal cross-sectional view of a caisson. It is a figure explaining the sinking method of the caisson which concerns on embodiment of this invention, and is a schematic diagram corresponded to the AA cross section of FIG.

  Hereinafter, a caisson and caisson settlement method (open caisson method) according to an embodiment of the present invention will be described based on the drawings.

As shown in FIG. 1, in the present embodiment, the caisson 10 is constructed using the open caisson method. The caisson 10 is constructed in the ground by sequentially sinking the annular body (caisson rod body) 11 while excavating the ground G and connecting in a tubular shape. The plurality of annular bodies 11 are configured as side walls 12 of the caisson 10, and water is stored inside thereof.
The caisson 10 includes a side wall portion 12 to which a plurality of annular bodies 11 are connected, and a caisson blade port 13 provided at a lower end and opposed to the ground G.
The caisson blade port 13 has a tapered shape in which the inner circumferential surface 13 b is expanded toward the blade edge 13 a at the lower end.

A plurality of lubricant channels 14 and high-pressure fluid channels 15 extending in the vertical direction are provided on the side wall portion 12 so as to be dispersed around the entire circumference.
The lubricant passage 14 is a pipe for supplying a lubricant between the outer circumferential surface 10 a of the caisson 10 and the ground G around the caisson 10. A plurality of lubricant channels 14 are formed in plan view. A plurality of discharge ports 14 a are formed on the outer peripheral surface 10 a of the caisson 10, and the discharge ports 14 a communicate with the lubricant flow path 14. By supplying the lubricant from the upper end opening 14 b of the lubricant flow channel 14, the lubricant can be supplied between the ground G and the side wall 12.
The lubricant may be any material that can reduce the frictional resistance between the outer circumferential surface 10 a and the surrounding ground G when the caisson 10 sinks.

The high pressure fluid channel 15 is a pipe for injecting the high pressure fluid from the inner circumferential surface 13 b of the caisson blade port 13. A plurality of high-pressure fluid channels 15 are planarly formed. A plurality of injection holes 15 a are formed in the inner circumferential surface 13 b of the caisson blade port 13, and the injection holes 15 a communicate with the high pressure fluid flow path 15. By supplying the high pressure fluid from the upper end opening 15 b of the high pressure fluid channel 15, the high pressure fluid can be jetted to the opposed ground G.
In the present embodiment, a plurality of injection holes 15a are formed at intervals in the vertical direction of the caisson blade port 13, and a plurality of injection holes 15a are provided at intervals in the circumferential direction along the cutting edge 13a. There is.

Each injection hole 15 a is disposed so as to be capable of injecting high pressure fluid inward from the inner circumferential surface 13 b of the caisson blade port 13 toward the ground G. Moreover, the injection adjustment part 16 is provided for every one or several injection hole 15a. The injection adjustment unit 16 is configured to be able to adjust an injection state such as an injection direction, an injection amount, and an injection speed of each injection hole 15a. For example, the injection adjustment unit 16 may be provided with an electric valve or the like.
The high pressure fluid is a fluid having a pressure enough to break the ground G by being jetted toward the ground G, and may be, for example, pressurized air or high pressure water.

  In the caisson 10, a plurality of ultrasonic measuring devices 17 are provided on the inner circumferential surface 10b at intervals in the circumferential direction. The ultrasonic measurement device 17 can three-dimensionally measure the shape of the ground G inside the caisson blade port 13.

In the present embodiment, a control unit (not shown) for controlling each injection adjustment unit 16 is provided so as to adjust the injection state of some of the injection holes 15a based on the measurement results of each ultrasonic measurement device 17. ing. As shown in FIG. 2 and FIG. 3, when it is determined that there is a digging portion 18 where the ground G is raised locally below the caisson blade port 13, high pressure fluid is injected from the injection hole 15a near the digging portion 18 It can control so that it may inject toward the digging remaining part 18, and may not inject from the other injection hole 15a.
As another control method, when there is a digging portion 18, the flow rate and the flow velocity of the high pressure fluid injected to the digging portion 18 are increased, and the high pressure fluid sprayed to a place other than the digging portion 18 at the same time Flow rate or flow rate may be reduced.

Next, a method of constructing the caisson 10 (sinking method of the caisson 10) will be described.
In order to sink and build a caisson 10 having a caisson tip 13, the ground G is excavated to sequentially sink the annular body 11 prepared on the ground, and a plurality of annular bodies 11 are connected in a tubular shape to form a side wall portion Build 12
At the time of excavation, as shown in FIG. 2, the caisson blade port 13 was installed on the ground G, and the ground G inside and below the caisson blade port 13 was supported by the crane 19 in a state where water was stored inside the caisson 10 It excavates with a clamshell etc. and sinks the caisson 10 (the caisson tip 13 and the annular body 11) one by one.

  For example, when there is a ground G having a large N value, the ground G remains locally below the caisson edge 13 inside the caisson 10 as shown in FIGS. May occur. At this time, when the shape of the ground G is measured by the ultrasonic measurement device 17, based on the measurement results of the respective ultrasonic measurement devices 17, the digging left portion 18 where the ground G is raised locally below the caisson blade 13. Is determined to be present.

The control unit controls the injection adjustment units 16 to adjust the injection state of the injection holes 15a. For example, the injection adjustment unit 16 adjusts the injection state of the injection direction, injection amount, injection speed, and the like of the injection holes 15a in the vicinity of the digging remaining portion 18. The ground G of the undigging portion 18 is crushed and excavated by injecting the high-pressure fluid inward toward the undigging portion 18 inside and below the caisson blade port 13. Thereby, the caisson 10 (the caisson tip 13 and the annular body 11) can be sunk.
By connecting the annular body 11 while repeating such excavation and settlement of the caisson 10, a underground structure using the open caisson method can be constructed.

  According to the caisson 10 and the caisson settlement method as described above, since the caisson blade port 13 is provided with the injection holes 15a capable of injecting high pressure fluid toward the ground G, the ground G below the caisson blade port 13 is Drilling can be facilitated by injecting and breaking high pressure fluid. As a result, the sinking of the caisson 10 can be promoted. Moreover, even if it is the ground G with a large N value, high pressure fluid can be injected and crushed in the ground G under the caisson tip 13 to advance drilling, and the settlement of the caisson 10 can be suitably promoted.

  At this time, since the injection holes 15a can inject the high pressure fluid inward, the flow generated by the high pressure fluid, the soil of the ground G broken, etc. are kept inside the caisson 10. Thus, the influence of the caisson 10 on the ground G outside the caisson 10 can be suppressed, and for example, the simultaneous lowering of the caisson 10 during the settlement can be suppressed, and the settlement of the caisson 10 can be efficiently promoted.

Moreover, only a predetermined injection hole 15a is provided on the inner peripheral surface 13b of the caisson blade port 13 to supply high-pressure fluid, and a complicated structure for dividing and operating the caisson blade port 13 is not necessary, and it is simple. It can be realized by the structure.
Therefore, even in the ground G having a large N value, the caisson 10 can be easily sunk with a simple structure.

  The caisson 10 according to the present embodiment includes the ultrasonic measurement device 17 capable of measuring the shape of the ground G. Therefore, the shape of the ground G can be measured during or after excavation. As a result, the presence or absence of the digging left portion 18 of the ground G can be easily determined. Therefore, the caisson 10 can be efficiently sunk by injecting and crushing the high pressure fluid to the undigging portion 18.

  In the caisson 10 of the present embodiment, the injection adjustment unit 16 can adjust the injection state of the high-pressure fluid for each of the injection holes 15 a of the plurality of injection holes 15 a. Therefore, if the ground G below the caisson tip 13 has an uneven digging portion 18 or the like, the injection state is locally localized, for example, by increasing the flow rate or flow velocity of the high-pressure fluid injected from the injection hole 15a of the corresponding part. By adjusting in this way, the caisson 10 can be sunk evenly.

  In the present embodiment, the shape of the ground G is measured to determine the existence of the digging left portion 18 of the ground G, and the high pressure fluid is jetted and broken to the left digging portion 18 so that the caisson 10 can be sunk evenly. .

As mentioned above, although one Embodiment was described about the settlement method of caisson by this invention, this invention is not limited to said embodiment, It can change suitably in the range which does not deviate from the meaning.
For example, although the jet adjustment unit 16 and the ultrasonic measurement device 17 are installed in the above embodiment, the jet adjustment unit and the ultrasonic measurement device may be omitted.
Further, in the above embodiment, a plurality of flow paths are provided in the vertical direction (vertical direction) for the lubricant flow path 14 and the high pressure fluid flow path 15, but in the immediate vicinity of the discharge port 14a and the injection hole 15a, the circumferential direction is provided. A flow path communicating with the flow path may be formed, and the flow path extending in the vertical direction may be formed at only one place.
Moreover, although the said embodiment demonstrated the example which controls each injection adjustment part 16 by a control part based on the shape of the ground G measured by the ultrasonic measurement device 17, it measured by the ultrasonic measurement device 17 The injection state of each injection hole 15a may be manually adjusted based on the shape of the ground G.

DESCRIPTION OF SYMBOLS 10 caisson 11 annular body 12 side wall part 13 caisson blade mouth 13a blade tip 13b inner peripheral surface 14 lubricant flow path 14a discharge port 15 high pressure fluid flow path 15a injection hole 16 injection adjustment part 17 ultrasonic measuring device 18 digging portion G ground

Claims (5)

A caisson having a caisson blade port at its lower end,
A caisson characterized in that an injection hole capable of injecting high pressure fluid toward the ground is provided on the inner peripheral surface of the caisson blade port.   The caisson according to claim 1, further comprising an ultrasonic measuring device capable of measuring the shape of the ground.   A plurality of the injection holes are provided along the cutting edge of the caisson blade port, and an injection adjustment unit that adjusts the injection state of the high-pressure fluid for each of the partial injection holes is provided. The caisson described in. A caisson settlement method comprising: installing a caisson blade port of the caisson on a ground, excavating a ground inside and below the caisson blade port to sink the caisson,
A step of crushing and excavating the ground by injecting high pressure fluid from the injection holes provided on the inner circumferential surface of the caisson blade port toward the ground inside and below the caisson blade port, and sinking the caisson A method of sinking a caisson characterized by having. Measuring the shape of the ground to determine the presence or absence of the undigged portion of the ground;
When there is a digging portion of the ground, the high pressure fluid is injected to the digging portion of the ground to crush and dig the digging portion of the ground. A method of sinking a caisson according to claim 4.

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