JP6764691B2 - Caisson skeleton subsidence device - Google Patents

Description

The present invention relates to a caisson skeleton subsidence device , and particularly to a device for stably laying a caisson skeleton at a large depth.

In the pneumatic caisson method, when the caisson skeleton is sunk at a large depth of GL-80 m class, the lubricant method (for example, the method of injecting bentonite muddy water into the outer periphery of the caisson skeleton) has been conventionally carried out. At a depth, the effect of reducing the friction of the lubricant is reduced, and there is a concern that the frictional force between the outer peripheral surface of the caisson skeleton and the ground makes it difficult to lay the caisson skeleton and correct or suppress the inclination.

For this reason, the press-fitting anchor improves the sinking thrust of the caisson skeleton, or the frictional force between the outer peripheral surface of the caisson skeleton and the ground is injected by inserting an injection pipe from the ground around the caisson skeleton to inject bentonite muddy water. Or, measures are taken to build a loose area around the caisson skeleton by the boring hole method or the high-pressure stirring injection method, which is the area where the frictional force between the outer peripheral surface of the caisson skeleton and the ground is reduced. Has been done. Further, various techniques for reducing the frictional force between the outer peripheral surface of the caisson skeleton and the ground when laying the caisson skeleton have been proposed (for example, Patent Document 1, Patent Document 2, and Patent Document 3). reference).

The technique described in Patent Document 1 relates to a jet nozzle that injects a friction reducing agent toward the outside arranged on a caisson skeleton. This jet nozzle has a hole on the peripheral surface and the tip is closed, and the jet nozzle is arranged on the peripheral surface of the nozzle and deforms the shape by the supply pressure of the friction reducing agent supplied to the nozzle to close or close the hole. It is provided with a chain opening tool for opening and a protective tube for accommodating the chain opening tool and a nozzle to restrain the amount of deformation of the chain opening tool while having a certain distance on the side portion of the chain opening tool.

The technique described in Patent Document 2 relates to a multi-liquid consolidation type lubricant injection device for preventing air leakage in the pneumatic caisson method and preventing land collapse due to excavation subsidence. This multi-liquid solidified lubricant injection device is arranged with a check valve provided in each of a plurality of injection pipes for pumping the raw material of the multi-liquid solidified lubricant and facing the discharge direction of the raw material in the plurality of injection pipes. It has a multi-component mixing plate to be used. Then, a lubricant is provided near the tip of the cutting edge of the caisson skeleton, and a plurality of raw materials are jetted from a plurality of injection tubes via a check valve onto a multi-component mixing plate at substantially right angles and stirred to mix and lubricant. A lubricant discharge port that discharges the lubricant produced by mixing a plurality of raw materials from the vicinity of the tip of the blade edge of the caisson skeleton toward the ground, and a caisson sandwiching the lubricant discharge port. It is provided with first and second dispersion guide walls that are arranged in a band shape on the entire circumference of the blade edge of the skeleton and that guide and disperse the lubricant discharged from the lubricant discharge port on the entire circumference of the blade edge.

The technique described in Patent Document 3 relates to a method for reducing peripheral friction (friction force between the outer peripheral surface of the caisson skeleton and the ground) when the caisson skeleton penetrates. The method of reducing the peripheral friction at the time of penetrating the caisson skeleton is to inject a high-pressure gas toward the bottom ground in contact with the peripheral surface of the skirt through an air supply passage provided in the caisson skeleton. The water sucked from the water supply passage by the injection of the high-pressure gas and the earth and sand separated by the injection are mixed and floated along the skirt portion.

Japanese Unexamined Patent Publication No. 2005-90022 Japanese Unexamined Patent Publication No. 2012-136882 JP-A-9-31209A

However, in the work of submerging the caisson skeleton at a large depth, it is difficult to correct the caisson skeleton once it is tilted, and there is a problem that the correction work requires a great deal of time and cost.

For example, in the method of improving the thrust by the press-fitting anchor, the thrust must be sunk at a large depth, which requires a large amount of thrust, a large-scale thrust device must be used, and the thrust cannot be easily controlled. It was.

In addition, in the method of injecting bentonite muddy water around the caisson skeleton, bentonite muddy water with low injection pressure flows into the part where the ground is weak , and the efficiency is high in the place where the frictional force between the outer peripheral surface of the caisson skeleton and the ground is high. There were times when it didn't flow in.

Further, in the method of constructing a loose area around the caisson skeleton by the boring hole method or the high pressure stirring injection method, when the caisson skeleton is sunk, the periphery of the caisson skeleton is in a pressure state by a high pressure compressor, so that the outer circumference of the caisson skeleton In the immediate vicinity of the caisson skeleton, which is most effective in reducing the frictional force between the surface and the ground, there was a risk that air holes would communicate to the ground and groundwater would be mounded.

Furthermore, the techniques described in each of the cited references described above can reduce the frictional force between the outer peripheral surface of the caisson skeleton and the ground when laying the caisson skeleton, but the laying is reliable and efficient. There was room for further ingenuity in order to do this.

The present invention has been proposed in view of the above circumstances, and appropriately controls the frictional force between the outer peripheral surface of the caisson skeleton and the ground to correct the inclination and lay the caisson skeleton reliably and efficiently. It is an object of the present invention to provide a caisson skeleton subsidence device capable of capable.

The caisson skeleton subsidence device according to the present invention has the following features in order to achieve the above-mentioned object. That is, the sinking apparatus of the caisson precursor according to the present invention, at different respective circumferential and installation location in the vertical direction of the caisson skeleton provided at a plurality of positions, high pressure liquid toward the outer circumferential surface of the caissons skeleton upward an injection nozzle which can be injection, provided in the vicinity of the injection nozzle, on the basis of the tribometer and the friction force measured for each tribometer to measure the frictional force between the outer peripheral surface and the natural ground caissons skeleton, each The range of the loose region, which is the region where the frictional force between the outer peripheral surface of the Kason skeleton and the ground is reduced by the liquid injection control means for controlling the injection of the liquid from the injection nozzle and the liquid injected from the injection nozzle , is measured. It is equipped with a loosening area measuring means .

Then, the liquid injection control means promotes the subsidence of the caisson skeleton by increasing at least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle when the range of the loosening region falls below the reference range. Correct the tilt with.

Further, it is preferable to provide a check valve in the pipe for delivering the liquid to the injection nozzle to allow the liquid to be injected from the injection nozzle when the liquid having a predetermined pressure or higher is delivered.

Further, it is preferable that the injection nozzle is provided with an injection port capable of injecting a liquid with a predetermined width.

Further, it is preferable that the injection nozzle can inject at least one of liquid, lubricant, air and a solidifying material.

In the caisson skeleton subsidence device according to the present invention, the range of the loosening region, which is the region where the frictional force between the outer peripheral surface of the caisson skeleton and the ground is reduced, is measured, and when the range of the loosening region falls below the reference range, At least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle is increased.

In the caisson skeleton, the friction cut at the tip of the caisson skeleton secures a certain loose area (the area where the frictional force between the outer peripheral surface of the caisson skeleton and the ground is reduced). According to the caisson skeleton subsidence device according to the present invention, when the caisson skeleton is submerged, a loosened area can be secured in a certain range, so that the caisson skeleton can be laid down and the inclination can be corrected.

Therefore, the frictional force between the outer peripheral surface of the caisson skeleton and the ground can be appropriately controlled without using a large-scale device and by simple injection control, and the inclination of the caisson skeleton can be corrected and sunk reliably and efficiently. It becomes possible to do it.

The schematic vertical sectional view of the caisson skeleton subsidence apparatus which concerns on embodiment of this invention. Schematic cross-sectional view of the caisson skeleton subsidence device according to the embodiment of the present invention. Explanatory drawing of the injection nozzle. The explanatory view of the promotion of the subsidence by the subsidence method using the caisson skeleton subsidence device which concerns on embodiment of this invention. The explanatory view of the inclination correction by the subsidence method using the caisson skeleton subsidence device which concerns on embodiment of this invention.

Hereinafter, the caisson skeleton subsidence device according to the embodiment of the present invention will be described with reference to the drawings. Figures 1-5 serve to illustrate the sinking apparatus of the engagement Ru caisson precursor to embodiments of the present invention, FIG. 1 is a schematic longitudinal sectional view of the sinking apparatus of the caisson skeleton, FIG. 2 is a schematic cross the sinking device caissons skeleton FIG. 3 is an explanatory view of the injection nozzle, FIG. 4 is an explanatory view of promoting the sinking of the caisson skeleton, and FIG. 5 is an explanatory view of tilt correction of the caisson skeleton.

<Overview of caisson skeleton subsidence device >
As shown in FIGS. 1 and 2, the cason skeleton subsidence device according to the embodiment of the present invention includes the injection nozzles 20 provided at a plurality of locations with different installation locations in the circumferential direction and the vertical direction of the cason skeleton 10. , A friction meter 30 provided in the vicinity of each injection nozzle 20 to measure the frictional force between the outer peripheral surface of the Kason skeleton 10 and the ground, and the liquid injected from the injection nozzle 20 to bring the outer peripheral surface of the Kason skeleton 10 together. It is provided with a loosening area measuring means 60 for measuring a range of a loosening area which is a region where the frictional force with the ground is reduced . Then, when the range of the loose area measured by the loose area measuring means 60 falls below the reference range, the caisson skeleton 10 is increased by increasing at least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle 10. It is designed to promote subsidence and correct the slope.

In addition, since the peripheral friction meter (friction meter 30) currently in widespread use is large in size, there may be restrictions on the mounting location. Therefore , a loose region (ground due to the liquid injected upward from the injection nozzle 20), which is a region where the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground is reduced only by the peripheral friction meter (friction meter 30). And the caisson skeleton 10) may not be accurately measured. Therefore, the loosening area measuring means 60 for measuring the range of the loosening area, which is the area where the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground is reduced by injecting the liquid from the injection nozzle 20 , is provided. Then, when the range of the loosening region falls below the reference range, by increasing at least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle 20, it is easy to correct the inclination of the caisson skeleton 10 and promote the subsidence. Can be controlled.

<Injection nozzle>
The injection nozzle 20, as shown in FIGS. 1 to 3, in the circumferential direction and the vertical direction of the caisson building frame 10 at different installation locations respectively provided at a plurality of positions, the direction from the outer circumferential surface of the caisson skeleton 10 upward It is possible to inject liquid at high pressure. The base end portion of the injection nozzle 20 is communicated with a delivery pipe 40 provided in the caisson skeleton 10. Further, it is preferable that each injection nozzle 20 is provided with a check valve (not shown), and when a liquid having a predetermined pressure or higher is delivered, the injection of the liquid from the injection nozzle 20 is permitted.

Although the delivery pipe 40 is connected to each injection nozzle 20 in communication, a separate delivery pipe 40 may be connected to each injection nozzle 20 in communication, or a delivery pipe 40 common to a plurality of injection nozzles 20 may be connected in communication. However, an on-off valve (not shown) may be provided in each injection nozzle 20. Further, although not shown, the delivery pipe 40 is provided with a tank, a pressure feed pump, and the like for storing the liquid ejected from the injection nozzle 20.

The on-off valve is composed of, for example, a solenoid valve and is a valve for opening and closing the delivery path to each injection nozzle 20, and by opening and closing this on-off valve, the injection and stop of the liquid from each injection nozzle 20 are controlled. can do. The opening and closing of the on-off valve is controlled by the liquid injection control means 50.

The injection port of the injection nozzle 20 is set to an appropriate size according to the injection amount and injection pressure of the liquid to be injected. Generally, it has a circular injection port, but it is preferable to use an injection port capable of injecting a liquid with a predetermined width.

In the present embodiment, when the caisson skeleton is sunk, the liquid jetted from the injection nozzle 20 in order to reduce the frictional force between the outer peripheral surface of the caisson skeleton and the ground is water, bentonite muddy water, lubricant, cement milk. , Air, etc., but other objects such as lubricant, air, and solidifying material may be injected from the injection nozzle 20. In this case, one of these objects may be jetted, or a plurality of types of objects may be mixed and jetted. When the lubricant or the solidifying material is injected from the injection nozzle 20, the injection pipe and the injection port of the lubricant or the solidifying material can be omitted.

Further, although not shown, a lubricant injection pipe and a lubricant injection port communicating with the lubricant injection pipe are separately provided to inject liquid at high pressure from the injection nozzle 20 to loosen the ground around the Kason skeleton and in the vicinity of the injection nozzle 20 . By injecting the lubricant from a certain lubricant injection port, the ground can be made independent in the gap formed around the Kason skeleton, and the ground collapse can be prevented.

Further, the injection nozzle 20 is provided so as to project outward from the peripheral surface of the caisson skeleton 10. Therefore, when the caisson skeleton 10 is laid down, the injection nozzle 20 may be caught in the surrounding ground. Therefore, although not shown, it is preferable to attach a cover member for protecting the injection nozzle 20.

<Tribometer>
The friction meter 30 is a device for measuring the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground, and is installed in the vicinity of each injection nozzle 20. In addition, instead of always providing a friction meter 30 in the vicinity of each injection nozzle 20, one friction meter 30 may be provided for a plurality of injection nozzles 20. That is, the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground does not increase only at the installation position of each injection nozzle 20, but increases in the installation range of the plurality of injection nozzles 20. Therefore, the injection nozzle 20 and the friction meter 30 do not necessarily have to be installed in a one-to-one relationship.

The measurement signal of the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground measured by the tribometer 30 is transmitted to the liquid injection control means 50 and used for liquid injection control from the injection nozzle 20. The signal transmission / reception between the friction meter 30 and the liquid injection control means 50 may be performed via an electric cable that electrically connects the two, or may be performed by wireless communication using a wireless communication means. Good.

<Loose area measuring means>
The loose region measuring means 60 is a device for measuring the range of the loose region, which is a region where the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground is reduced by injecting a liquid from the injection nozzle 20. , The caisson skeleton 10 is provided at a plurality of locations at different locations in the circumferential direction and the vertical direction. As described above, the loosening region, which is the region where the frictional force between the outer peripheral surface of the Kason skeleton 10 and the ground is reduced, is basically the frictional force between the outer peripheral surface of the Kason skeleton 10 and the ground. Although it can be measured by the friction meter 30 for measuring the looseness region, the loosening region may not be measured only by the friction meter 30. Therefore, as the loosening region measuring means 60, a thermometer (thermocouple, optical fiber thermometer, etc.) and a soil pressure gauge, which are devices for indirectly measuring the frictional force between the outer peripheral surface of the Kason skeleton 10 and the ground. , An elastic wave measuring device, an ultrasonic measuring device, or the like can be used as the loosening region measuring means 60. When a thermometer is used, the range of the loosened region is measured by measuring the difference between the jet liquid injected at high pressure on the outer peripheral surface of the caisson skeleton and the groundwater temperature. When a soil pressure gauge is used, the pressure of the ground acting on the outer peripheral surface of the caisson skeleton is measured to measure the range of the loosened area. When an elastic wave measuring device or an ultrasonic measuring device is used, the propagation velocity of the elastic wave or the ultrasonic wave is measured to measure the range of the loosening region.

<Liquid injection control means>
The liquid injection control means 50 is a means for controlling the injection of liquid from each injection nozzle 20 based on the frictional force measured by each friction meter 30, and specifically, the cason skeleton measured by each friction meter 30. When the frictional force between the outer peripheral surface of 10 and the ground shows an increasing tendency, it is provided in the vicinity of the tribometer 30 which measures the increasing tendency of the frictional force between the outer peripheral surface of the cason skeleton 10 and the ground. Control is performed so that the liquid is injected at high pressure from the injection nozzle 20 toward the upper peripheral surface of the cason skeleton 10. By performing such control, it is possible to promote the laying of the caisson skeleton 10 and correct the inclination. The threshold value of the frictional force between the outer peripheral surface of the caisson skeleton 10 that injects liquid from the injection nozzle 20 at high pressure and the ground depends on various factors such as the size, shape, subsidence depth, and soil quality of the surrounding ground of the caisson skeleton 10. Based on this, it can be set as appropriate.

In the liquid injection control means 50, for example, the operator observes the measured value of each friction meter 30 and inputs an operation based on the observation result to operate the on-off valve of the injection nozzle 20 to perform the liquid injection. The device comprises a device for transmitting a control signal for injecting a liquid at high pressure from the injection nozzle 20.

Further, the liquid injection control means 50 is configured by the computer, the control program installed on the computer, and the peripheral devices of the computer, and the measurement signal from each friction meter 30 is received to set the measured value ( friction force ) to a predetermined value. When the amount exceeds the limit, the on-off valve of the injection nozzle 20 to which the liquid should be injected may be automatically controlled to inject the liquid from the injection nozzle 20 at high pressure. The measured value ( friction force ) may increase transiently due to various factors such as the size, shape, subsidence depth, and soil quality of the surrounding ground of the caisson skeleton 10, and in this case, the measurement is performed in a short time. The value ( friction force ) will return to the predetermined value or less. Therefore, it is preferable to control the liquid to be injected at high pressure from the injection nozzle 20 when the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground continues to exceed a predetermined value for a predetermined time.

Further, the liquid injection control means 50 is controlled so as to increase at least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle 20 when the range of the loose area measured by the loose area measuring means 60 falls below the reference range. I do. As a result, even when the loosened area is narrower than the assumed range, the loosened area can be corrected, and the inclination of the caisson skeleton 10 can be corrected or sunk reliably. In particular, the larger the cross section of the caisson skeleton 10, the higher the possibility that the soil quality will differ depending on the construction site, and even in such a case, appropriate measures can be taken.

<Caisson skeleton subsidence control>
A method of submerging the caisson skeleton 10 using the caisson skeleton 10 subsidence device according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic diagram when the inclination of the caisson skeleton 10 is corrected, and FIG. 5 is a schematic diagram when the subsidence of the caisson skeleton 10 is promoted. It should be noted that not only the inclination correction and the subsidence promotion of the caisson skeleton 10 are performed separately, but also both are performed at the same time, and the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground (FIGS. 4A and 5). By appropriately controlling (referred to as the peripheral frictional force in (a)), the inclination of the caisson skeleton 10 can be corrected and sunk reliably and efficiently.

<Promotion of subsidence>
As shown in FIG. 4, when there is a place where the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground rises above a predetermined value (a), the outer peripheral surface of the caisson skeleton 10 and the ground High-pressure injection of liquid from the injection nozzle 20 installed near the friction meter 30 that measured the frictional force between the caisson skeletons 10 (b) increased the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground . Friction cut at the location (reducing the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground ), and further injection of lubricant at the location to prevent the ground collapse (c). The laying of the caisson skeleton 10 can be promoted.

<Inclination correction>
As shown in FIG. 5, when the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground is higher than a predetermined value on the peripheral surface of the caisson skeleton 10, and the caisson skeleton 10 is tilted (a). ), High-pressure injection of liquid from the injection nozzle 20 installed near the friction meter 30 that measures the frictional force between the outer peripheral surface of the caisson skeleton 10 and the ground (b), and the caisson skeleton 10 Friction cut is performed at the part where the frictional force between the outer peripheral surface and the ground is increased ( the frictional force between the outer peripheral surface and the ground of the caisson skeleton 10 is reduced), and further, the part where the sedimentation is delayed. The inclination of the caisson skeleton 10 can be corrected by excavating the face portion and causing it to sink in advance (c).

10 Caisson skeleton 20 Injection nozzle 30 Friction meter 40 Delivery pipe 50 Liquid injection control means 60 Loose area measuring means

Claims (4)

In the circumferential direction and the vertical direction of the caisson precursor at different installation locations respectively provided at a plurality of positions, an injection nozzle capable of high-pressure injection liquid toward the outer circumferential surface of the caissons skeleton upward,
A tribometer provided in the vicinity of each of the injection nozzles and measuring the frictional force between the outer peripheral surface of the caisson skeleton and the ground, and
A liquid injection control means that controls the injection of liquid from each of the injection nozzles based on the frictional force measured by each of the friction meters.
Loose area measuring means for measuring the range of the loose area, which is the area where the frictional force between the outer peripheral surface of the caisson skeleton and the ground is reduced by the liquid injected from the injection nozzle.
With
The liquid injection control means promotes the subsidence of the caisson skeleton by increasing at least one of the injection pressure and the injection amount of the liquid injected from the injection nozzle when the range of the loosening region falls below the reference range. And correct the tilt,
A caisson skeleton subsidence device characterized by this. The first aspect of claim 1, wherein a check valve is provided in a pipe for delivering a liquid to the injection nozzle to allow the liquid to be injected from the injection nozzle when the liquid having a predetermined pressure or higher is delivered. Caisson skeleton subsidence device. The caisson skeleton subsidence device according to claim 1 or 2, wherein the injection nozzle includes an injection port capable of injecting a liquid with a predetermined width . The caisson skeleton subsidence device according to any one of claims 1 to 3, wherein the injection nozzle can inject at least one of a liquid, a lubricant, air, and a solidifying material .

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