JP3697429B2 - Sheet pile embedding auxiliary device and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention facilitates the propulsion of a sheet pile into the ground when the sheet pile is press-fitted into the ground and embeds the sheet pile in a short time even on a hard ground. The present invention relates to a sheet pile embedding auxiliary apparatus and a sheet pile embedding method using the same.
[0002]
[Prior art]
As a method of embedding a sheet pile (steel sheet pile) in the ground, a method of driving by static load using a press-fitting / pulling machine or a method of driving by vibration using a vibro hammer is known. In addition, depending on conditions such as the depth of the sheet pile press-in and the ground, water jet method is used to assist the press-fitting of the seat pile by injecting water at a high pressure from the lower end of the sheet pile, and water is injected at a higher pressure. An air combined water jet method for injecting air is used.
[0003]
In the water jet method, a pipe is attached along the longitudinal direction of the sheet pile, a nozzle is provided at the lower end of the pipe, a pump is connected to the upper end of the pipe, and high-pressure water pumped from the pump is supplied from the nozzle. It is to be jetted. This jet water digs up earth and sand and gravel beyond the lower end of the sheet pile, mixes with water and discharges the earth and sand and gravel to the ground, and assists the press-in of the sheet pile. In addition, in the air combined water jet method in which air is injected at a high pressure in addition to water, the tip ground is excavated with high-pressure water, and the excavated soil particles are put on the ground surface with an upward flow of air stronger than the upward flow of water. The lower end of the sheet pile is propelled into the excavated space while discharging.
[0004]
In these water jet methods and water jet methods combined with air, high pressure water is injected to increase the pore water pressure at the tip ground, thereby moving the soil particles, and the soil particles are moved to the ground surface along with the rising flow of water and air. Discharge. In particular, in the gravel layer and the like, an excluded volume is formed by discharging the soil particles, and the movement of stones and rocks is facilitated, and the press-fitting of the sheet can be facilitated.
[0005]
[Problems to be solved by the invention]
However, in a hard and consolidated gravel layer or a gravel layer with a large particle size, the press-fitting efficiency of the sheet pile is lowered even if the above-described air-jet water jet method is used. For this reason, conventionally, attempts have been made to prevent a decrease in press-fitting efficiency by increasing the pressure of high-pressure water and the injection amount. The purpose of increasing the pressure of high-pressure water is to increase the excluded volume of soil particles by increasing the excavation depth and facilitate the movement of stones and rocks. However, if it hits stones or rocks that are larger than the area that can be excavated by high-pressure water, the jet will be turbulent, soil particles cannot be excluded, and the press-in efficiency of the sheet pile will be significantly reduced.
[0006]
The purpose of increasing the injection amount of high-pressure water is to increase the amount of high-pressure water jets that are excavated by the high-pressure water and to increase the amount of soil particles excavated by the high-pressure water to the ground surface. It is. However, even if the injection amount of the high-pressure water is increased, there is a problem that the excluded volume is not formed so large and the press-fitting efficiency is not improved. Conversely, there is also a problem that the amount of muddy water containing a large amount of soil particles increases as the injection amount increases.
[0007]
In view of the problems in the conventional air combined water jet method, the present invention enhances the excavation efficiency of earth and sand by increasing the mutual complementing action of the high pressure water to be injected and the high pressure air, and allows the sheet pile to be underground with higher efficiency. An object of the present invention is to provide a sheet pile embedding auxiliary device that can be press-fitted into a sheet and to embed the sheet pile, and to embed a sheet pile using the same.
[0008]
[Means for Solving the Problems]
In the present invention, in order to achieve the above-mentioned object, water is not ejected straight from the nozzle 6 provided at the lower end of the sheet pile 1, but the water is obliquely eccentrically inclined with respect to the rotation center axis of the nozzle 6. , And the sheet pile 1 is press-fitted while the nozzle 6 is rotated about its rotation center axis. Furthermore, high pressure air is injected through an air injection groove 21 provided on the outer periphery of the rotating nozzle 6 so that the high pressure air is injected as a rotating flow around the high pressure water.
[0009]
That is, the sheet pile embedding assisting device according to the present invention includes an outer tube 3 fixed along the longitudinal direction of the sheet pile 1, an inner tube 4 accommodated in the outer tube 3, and a lower end of the sheet pile 1. The nozzle 6 is provided in the lower end portion of the outer tube 3 fixed to the section, and injects high-pressure water sent through the inner tube 4 downward from the lower end of the sheet pile 1, and the nozzle 6 is connected to the outer tube 3. The nozzle 6 injects high-pressure water obliquely downward and eccentrically with respect to the center of rotation.
Further, a nozzle 5 is provided at the lower end of the outer tube 3, and an air injection groove 21 for injecting high-pressure air in the outer peripheral vertical direction of the nozzle 6 of the inner tube 4 inside the nozzle 5 is provided.
[0010]
Further, in the sheet pile embedding method according to the present invention using the sheet pile embedding assisting device, high pressure water is ejected from the nozzle 6 at the tip of the inner tube 4 and air jet provided in the outer peripheral vertical direction of the nozzle 6. By injecting high-pressure air from the groove 21, high-pressure air is injected around the high-pressure water injected from the nozzle 6 of the inner tube 4, and the sheet pile 1 is pressed into the ground while the nozzle 6 is rotated by the motor 7. To do.
[0011]
In the sheet pile embedding method as described above, the rotating nozzle 6 injects high-pressure water obliquely downward and inclined with respect to the rotation center, so that the ground excavation range by the water jet flow is expanded. Furthermore, when there are large stones, rocks, etc. in the gravel layer etc. by jetting high pressure air from around the nozzle 6 around the high pressure water, the surrounding soil particles are moved by the upward flow of water and air. By discharging the soil particles, movement of stones and rocks becomes easy. Therefore, when the sheet pile 1 is press-fitted, those stones and rocks can easily escape, so that the press-fitting resistance of the sheet pile can be reduced.
[0012]
In particular, the nozzle 5 at the lower end of the outer tube 3 is provided outside the nozzle 6 of the inner tube 4, and together with the high-pressure air injected through the air injection groove 21 provided in the outer peripheral vertical direction of the inner nozzle 6, By injecting the high-pressure water injected from the nozzle 6 of the tube 4, the following action is obtained. One is that it is possible to prevent soil and sand from entering between the outer tube 3 and the inner tube 4 by maintaining a high pressure between the outer tube 3 and the rotating inner tube 4 with high-pressure air. Second, the high-pressure air ejected from the periphery of the nozzle 6 is ejected along the periphery of the water jet ejected from the nozzle 6 at the lower end of the inner tube 4 to reduce the flow velocity of the water jet in water. It has the effect of extending the excavation distance of the ground by keeping water to a minimum. Third, the excavated soil particles can be discharged to the surface by a strong upward flow of air.
[0013]
Further, the nozzle 6 is rotated to inject high pressure by injecting air from the nozzle 5 at the lower end of the outer tube 3 through the air injection groove 21 provided in the outer peripheral vertical direction of the nozzle 6 of the inner tube 4 rotating inside. High-pressure air injected from the nozzle 5 at the lower end of the outer tube 3 together with water is also injected as a rotating flow around the high-pressure water. The rotation direction of the high-pressure air is the same as the rotation direction of the high-pressure water ejected by the nozzle 6 of the inner tube 4. Thereby, the effect | action by the above jet of water can be made more effective.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described specifically and in detail with reference to the drawings.
FIG. 1 is a view showing a lower end side of a sheet pile 1 that is press-fitted into the ground. As shown in FIG. 1, a sheet pile embedding according to an embodiment of the present invention having a double structure of an outer tube 3 and an inner tube 4 along the longitudinal direction of the inner center of the sheet pile 1, that is, the longitudinal direction. The tube that forms the auxiliary device is fixed. On the lower end side of the sheet pile 1, the nozzle 5 connected to the lower end of the outer tube 3 is fixed to the central portion of the lower end portion of the sheet pile 1 by a metal plate-like fixing member 2 bent into a U shape. As will be described in detail later, the inner tube 4 is rotatably supported in the outer tube 3.
[0015]
FIG. 2 is a side view in which only the sheet pile 1 is vertically cross-sectionally shown, and shows both upper and lower ends where the middle of the sheet pile 1 and the double pipe is omitted. As shown in FIG. 2, the upper end side of the outer pipe 3 of the double pipe is attached to the upper end side of the seat pile 1 by a fixture 15 and a hook 14. Further, a motor 7 for rotating the inner tube 4 is attached to the upper end of the inner tube 4 via a rotation transmission unit 8.
[0016]
4 shows an upper end of the outer tube 3 and the inner tube 4 showing a motor 7 for rotationally driving the inner tube 4 in the outer tube 3 and a rotation transmitting portion 8 for transmitting the rotational force to the inner tube 3. It is sectional drawing of a part. The motor 7 is not shown in cross section.
An upper end of the outer tube 3 is connected to a cylindrical frame 20, and a motor 7 as a drive source such as a pneumatic motor, a hydraulic motor, and an electric motor is attached on the frame 20. As will be described later, a port 9 for connection with a pump for supplying water and a hose is provided at an intermediate portion of the frame 20.
[0017]
A transmission shaft 28 is rotatably supported in the frame 20 by a bearing mechanism such as a radial bearing or a thrust bearing. The lower end side of the transmission shaft 28 is connected to the upper end of the inner tube 4 inside the upper end portion of the outer tube 3. Accordingly, the upper end of the inner tube 4 is rotatably supported by the frame 20 via the transmission shaft 28. Further, a water passage 29 is formed on the central axis of the lower half of the transmission shaft 28, and this water passage 29 communicates with the port 9 on the upper end side thereof, and in the inner pipe 4 on the lower end side thereof. It leads to the water passage 16.
[0018]
The upper end side of the transmission shaft 28 is connected to the output shaft of the motor 7, and the inner tube 4 is rotated in the outer tube 3 by driving the motor 7.
In the vicinity of the upper end of the outer tube 3, a port 10 is provided for connection via a hose and a pump for supplying air, as will be described later. The port 10 communicates with an air passage 17 formed in a gap between the outer tube 3 and the inner tube 4.
[0019]
FIG. 5 is a cross-sectional view of the lower ends of the outer tube 3 and the inner tube 4 and the nozzles 5 and 6 connected thereto.
A cylindrical nozzle 5 is fitted and connected to the lower end of the outer tube 3, and this nozzle 5 is fixed to the lower end portion of the sheet pile 1 by the metal plate-like fixing member 2 described above.
[0020]
A nozzle 6 of the inner tube 4 is rotatably fitted inside the nozzle 5 of the outer tube 3. The nozzle 6 is connected to the lower end of the inner tube 4, and the rotation of the inner tube 4 can be transmitted to the nozzle 6 in this state. The nozzle 6 has a water spout 19 connected to the water passage 16 of the inner tube 4, and this spout 19 is eccentrically inclined with respect to the central axis that is the center of rotation of the inner tube 4.
[0021]
The outer peripheral surface of the nozzle 6 of the inner tube 4 is basically supported in the nozzle 5 so as to be rotatable by sliding in contact with the inner peripheral surface of the nozzle 5 of the outer tube 3. However, a plurality of spline-like grooves 21 are formed in the longitudinal direction on the outer peripheral surface of the nozzle 6 of the inner tube 4. The air passage 17 formed in the gap between the outer tube 3 and the inner tube 4 is an outlet 18 of the nozzle 5 of the outer tube 3 through a plurality of air injection grooves 21 formed on the outer periphery of the nozzle 6. Leads to. The outlet 18 of the nozzle 5 of the outer tube 3 is below the outlet 19 of the nozzle 6 of the inner tube 4.
[0022]
Next, a procedure for embedding the sheet pile 1 having such an embedding assisting device into the ground will be described.
As already described with reference to FIGS. 1 and 2, the nozzle 5 connected to the lower end of the outer tube 3 is fixed to the lower end portion of the sheet pile 1 by a metal plate-like fixing member 2 bent into a U shape. Further, the upper end of the outer tube 3 is attached to the upper end side of the seat pile 1 by a fixture 15 and a hook 14.
[0023]
In this state, as shown in FIG. 2 and FIG. 3, a water pump 26 is connected to the port 9 communicating with the water passage 16 in the inner pipe 4 via the pressure hose 11. Although not shown in FIG. 3, the water pump 26 can draw water from a water source such as a water tank. A compressor 25 is connected via a pressure hose 12 to a port 10 that leads to an air passage 17 that is a gap between the outer tube 3 and the inner tube 4. Further, a compressor 27 is connected to the motor 7 via the pressure hose 13 when the motor 7 is an air motor, for example, as a power source.
[0024]
In this state, the upper end of the sheet pile 1 is connected to a crane (not shown), and the sheet pile 1 is set up and set in the pile press-in machine 22. The embodiment shown in FIG. 3 shows an example in which a pile press-fitting and pulling machine of a type in which a pile is press-fitted into the ground by a static load is used as the pile press-in machine 22. The pile presser 22 is press-fitted into the ground, and the existing sheet pile 1 'embedded therein is used as a reaction force frame, and the pile presser 22 is fixed and held by a fixture 24, and then press-fitted. The sheet pile 1 is held by a holder 23 and pressed downward into the ground by applying a force.
[0025]
Thus, when the sheet pile 1 is press-fitted into the ground, the water pump 26 is driven, high-pressure water is sent to the water passage 16 in the inner pipe 4 via the pressure hose 11, and this water is jetted from the nozzle 6. . At the same time, the motor 7 is driven, and the nozzle 6 at the lower end thereof is rotated in the nozzle 5 of the outer tube 3 through the inner tube 4. At the same time, the compressor 25 is driven, high pressure air is sent to the air passage 17 between the outer tube 3 and the inner tube 4 via the pressure hose 12, and this high pressure air is ejected from the air injection groove 21 around the nozzle 6. To do.
[0026]
Since the jet outlet 19 of the nozzle 6 is inclined and decentered with respect to the rotation center, high-pressure water is jetted while rotating as shown in FIGS. Thereby, a wide range of the ground can be excavated. Furthermore, high-pressure air is injected from an air injection groove 21 provided in the outer peripheral vertical direction of the nozzle 6 of the inner pipe 4, and this is injected from behind the high-pressure water injected from the nozzle 6 to its surroundings. Here, since the nozzle 6 is rotating, the high-pressure air injected from the air injection groove 21 on the outer periphery is also injected as a rotating flow. The rotation direction of the high-pressure air is the same as the rotation direction of the high-pressure water ejected from the nozzle 6 of the inner tube 4. Further, as shown in FIG. 5, the air injection groove 21 of the nozzle 6 of the inner tube 4 is in front of the outlet 19 of the nozzle 6, and the air injection groove 21 of the nozzle 6 of the inner tube 4 and the nozzle 6 Both of the jet outlets 19 are in front of the jet outlets 18 of the nozzles 5 of the outer tube 3. For this reason, the high-pressure air or high-pressure water is jetted from the outlet 19 to the tip of the lower end of the sheet pile 1 while being guided by the nozzle 5 of the outer tube 3. Thereby, it is possible to suppress the disturbance of the high-pressure water to be injected and to increase the reach distance.
[0027]
When the sheet pile 1 is press-fitted to a predetermined depth and embedded, the press-fitting ends. Thereafter, the outer pipe 3 and the inner pipe 4 are lifted by a crane, and the lifting force is broken to pull up and collect only the outer pipe 3 and the inner pipe 4 to complete the embedding of the sheet pile 1. In the same manner, a necessary number of sheet piles 1 are sequentially press-fitted and embedded in necessary places.
[0028]
FIG. 7 is a graph showing the relationship between the embedding depth at the lower end of the sheet pile and the time to reach it when a sheet pile having a length of 12.0 m is used and is pressed into the ground at a maximum pressure of 10 t. It is. In FIG. 7, the “Example” is the one in which the nozzle 6 of the inner tube 4 is inclined as described above, and water is injected at a pressure of 100 kg / cm ² while rotating the nozzle 6, This is a case where the sheet pile is press-fitted while injecting air at a pressure of 7 kg / cm ² from between the outer tube 3 and the inner tube 4. In the “comparative example”, the nozzle of the inner tube has a straight nozzle outlet, and the sheet pile is press-fitted while jetting water and air at the same pressure without rotating the nozzle.
[0029]
As is apparent from the results shown in FIG. 7, in the example of the present invention, a time difference of 8 minutes occurred when the sheet pile was press-fitted to a depth of 12 m as compared with the comparative example. As described above, the nozzle 6 of the inner tube 4 has an inclined nozzle outlet, and water is injected while the nozzle 6 is rotated, and air is blown between the outer tube 3 and the inner tube 4. This is due to the result of press-fitting while jetting.
[0030]
【The invention's effect】
As described above, in the sheet pile embedding auxiliary device according to the present invention and the sheet pile embedding method using the same, the complementary operation of the high pressure water ejected from the rotating nozzle 6 and the high pressure air ejected from the surroundings becomes good. Thus, the excavation efficiency of the earth and sand of the sheet pile 1 to be press-fitted is high, and the sheet pile 1 can be press-fitted into the ground and embedded with higher efficiency. Thereby, it is possible to reliably embed the sheet pile 1 and shorten the construction time.
[Brief description of the drawings]
FIG. 1 is a view showing a lower end side of a sheet pile provided with an embodiment of an embedding assisting device according to the present invention.
FIG. 2 is a side view of the embedding assisting device according to an embodiment of the present invention and a sheet pile provided with the same, with only the sheet pile vertically sectioned.
FIG. 3 is a schematic view showing a state in which a sheet pile provided with an embodiment of the embedding assisting device according to the present invention is press-fitted into the ground using a pile press-fitting and drawing machine and is buried.
FIG. 4 is a partial cross-sectional view showing a motor for rotationally driving the inner tube in the outer tube and a rotation transmitting unit for transmitting the rotational force to the inner tube in the embodiment of the implantation assisting device according to the present invention. FIG.
FIG. 5 is a cross-sectional view of an outer tube, a lower end portion of the inner tube, and a portion of the nozzle connected to the outer tube in the embodiment of the implantation assisting device according to the present invention.
FIG. 6 schematically shows a state of a front end portion of a sheet pile when the sheet pile having one embodiment of the embedding assisting device according to the present invention is press-fitted into the ground using a pile press-fitting and drawing machine and embedded. It is a longitudinal cross-sectional view.
FIG. 7 shows the depth of embedding at the lower end of the sheet pile when the sheet pile having one embodiment of the embedding assisting device according to the present invention is press-fitted into the ground using a pile press-fitting and drawing machine, and the depth reached. It is a graph which shows the relationship with time to do.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sheet pile 3 Outer tube 4 Inner tube 5 Outer tube nozzle 6 Outer tube nozzle 7 Motor 21 Nozzle air injection groove

Claims (3)

An auxiliary device for embedding the sheet pile (1) in the ground, the outer tube (3) fixed along the longitudinal direction of the sheet pile (1), and housed in the outer tube (3) The inner pipe (4) and the outer pipe (3) fixed to the lower end of the sheet pile (1) are provided in the lower end of the outer pipe (3), and the high pressure water sent through the inner pipe (4) is supplied to the sheet pile. A nozzle (6) that injects downward from the lower end of (1), and a motor (7) that rotates the nozzle (6) in the lower end of the outer tube (3), the nozzle (6) A sheet pile embedding assisting apparatus that jets high-pressure water obliquely downward and eccentrically with respect to the rotation center. An air injection groove (21) having a nozzle (5) at the lower end of the outer pipe (3) and jetting high-pressure air in the outer peripheral vertical direction of the nozzle (6) of the inner pipe (4) inside the nozzle (5). The sheet pile embedding assisting device according to claim 1, wherein: A method of embedding a sheet pile (1) in the ground, wherein the sheet pile embedding auxiliary device according to claim 2 is used to inject high-pressure water from a nozzle (6) at the tip of the inner tube (4). At the same time, high pressure air is injected from the air injection groove (21) provided in the outer peripheral vertical direction of the nozzle (6), so that high pressure water is injected around the nozzle (6) of the inner pipe (4). A method of embedding a sheet pile, wherein the sheet pile (1) is press-fitted into the ground while injecting air and rotating a nozzle (6) with a motor (7).

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