JP6855104B2 - How to set the air pressure condition of the pneumatic caisson and its work room and man's air pressure room - Google Patents

Description

The present invention relates to a pneumatic caisson used for construction of an underground structure and a method for setting atmospheric pressure conditions in a working room and a man's air chamber.

When excavating under the ground while suppressing the ingress of groundwater, the excavation work room should be under high pressure. Working under high pressure is both mentally and physically burdensome for the worker.

For this reason, unmanned technology for high-pressure work has been developed and put into practical use by remote control on the ground, but in the end, workers must go in and out of the work room under high pressure for inspection and other reasons.

There are legal restrictions on high-pressure work in the work room from the viewpoint of safety.

As this regulation, conventionally, the atmospheric pressure up to 0.4 MPa has been presented in "Appendix 1" of Articles 15 and 18 of the High Pressure Occupational Safety and Health Regulations. However, due to the revision of the law that came into effect on April 1, 2015, the restriction of "Appendix 1" was abolished, and it became obligatory for the business operator to calculate the "timetable" to ensure the safety of high-pressure work. As a result, high-pressure work of 0.4 MPa or more is possible on the premise that prevention of high-pressure obstacles is taken into consideration, and it has become possible to legally respond to construction projects such as deep underground structures.

Japanese Patent Application Laid-Open No. 2003-336265

In the pneumatic caisson of Patent Document 1, the slab is a man lock (man air chamber) having a double slab structure having two slabs, a ceiling slab and an upper slab.

Recently, the construction of deep underground structures with an increasing excavation depth is increasing, and as shown in FIG. 6, the air pressure in the working room 5'in the pneumatic caisson method is as high as 0.7 MPa, for example. This pressure also acts on the upper slab 10'. Therefore, the upper slab 10'must be strengthened as the atmospheric pressure rises, and the thickness of the reinforced concrete member constituting the upper slab 10'has become very thick.

Further, in the past, the pressurizing / depressurizing part for workers was one of the space parts formed between the ceiling slab 4'and the upper slab 10', but due to the recent increase in atmospheric pressure, it is necessary for health management to prevent high pressure damage. Consideration has become more important.

As described above, if the upper slab is made thicker by increasing the atmospheric pressure, the construction cost will increase accordingly. Also, when the work is completed, the upper slab of the caisson body is not required as the final structure, so the upper slab must be disassembled. In this case, dismantling the thick upper slab has the problem that the removal cost is required, the construction period is lengthened, and the cost as a whole increases.

The present invention has been proposed in view of the above, and an object thereof is to prevent health problems of workers entering and exiting the work room, suppress an increase in the thickness of the upper slab, and reduce the thickness of the structural member. The purpose of the present invention is to provide a method for setting atmospheric pressure conditions in a pneumatic caisson and its working room and man-slab room with reduced pressure.

The present invention according to claim 1 is a pneumatic caisson having a double slab structure in which a high-pressure working environment that changes from the atmospheric pressure on the ground to the pressure in the work room is generated and the ceiling slab and the upper slab are provided. A first man air chamber that allows access to the work room is provided on the upper surface of the ceiling slab, and the space between the ceiling slab and the upper slab is used as a second man air chamber that includes the first man air chamber. The first man air chamber has a first air pressure / depressurization unit, the second man air chamber has a second air pressure / depressurization unit, and both can be accessed via a hatch. The pressure in the first and second man air chambers can be set lower in sequence, and the first man air chamber on which the pressure in the work chamber acts is a pressure-resistant member, and the pressure is lower than that of the first man air chamber. It is characterized in that the member thickness of the upper slab of the second man air chamber is reduced.
The present invention according to claim 2 is characterized in that, in the pneumatic caisson according to claim 1, a lower portion of a man shaft is provided in the second man-shelter chamber so as to penetrate the upper slab.
According to the third aspect of the present invention, in the pneumatic caisson according to the first aspect, the upper slab is smaller than the floor area of the ceiling slab, and a side wall is provided between the end of the upper slab and the ceiling slab. A space is provided between the side wall and the side wall of the caisson body.
The present invention according to claim 4 is characterized in that, in the pneumatic caisson according to claim 3, a lower portion of a man shaft is provided in the space portion, and the man shaft is connected to an openable and closable hatch provided on the side wall. And.
The present invention according to claim 5 is characterized in that, in the pneumatic caisson according to claim 1, a man shaft penetrating the upper slab is connected to the first man air chamber.
According to the sixth aspect of the present invention, in the pneumatic caisson according to the first aspect, at least one or more man-air chambers are connected in a laminated manner to the upper part of the first man-air chamber, and between the man-air chambers. Is characterized by having different air pressures, being able to enter and exit through a hatch, and having a man shaft connected to the uppermost man's caisson.
The present invention according to claim 7 is a pneumatic caisson having a double slab structure in which a high-pressure working environment that changes from the atmospheric pressure on the ground to the pressure in the work room is generated and the ceiling slab and the upper slab are provided. A first man air chamber that allows access to the work room is provided on the upper surface of the ceiling slab, and the space between the ceiling slab and the upper slab is used as a second man air chamber that includes the first man air chamber. The first man air chamber has a first air pressure / depressurization unit, the second man air chamber has a second air pressure / decompression unit, and both can be accessed via a hatch, and the pressure in the work chamber is used as described above. The pressure in the first and second man air chambers can be set low in sequence, and in the method of setting the pressure conditions of the work room and the man air chamber of this pneumatic caisson, the entrance and exit are between the ceiling slab and the upper slab, respectively. It is characterized by further adding a man-slab chamber having a hatch that can be opened and closed and having a pressurizing / depressurizing portion, and each man-slab chamber is set to have different pressures in sequence.

In the present invention, since a plurality of man's air chambers are provided on the ceiling slab and the air pressure in each man's air chamber is gradually lowered, there is an advantage that health hazards of workers can be prevented and safety is improved. ..
In addition, the first man air chamber on which the air pressure in the work room acts is made of a member with excellent pressure resistance, and the air pressure acting on the upper slab of the second man air chamber including the first man air chamber is reduced. This has the economic effect of preventing the thickness of the upper slab from increasing and reducing the thickness of the members of the upper slab, as well as shortening the dismantling work time and shortening the construction period. It has an economic effect.

Explanatory drawing of 1st Example of this invention. The explanatory view of the 2nd Example of this invention. The explanatory view of the 3rd Example of this invention. The explanatory view of the 4th Example of this invention. The explanatory view of the 5th Example of this invention. A conventional example is shown.

When considering the prevention of anticyclone damage in the man's air chamber, it is important to secure a large space where the limbs can be stretched as a way of spending a long decompression time. In terms of securing a large space, a man-air chamber made of reinforced concrete or the like that can freely form a shape is advantageous. As a characteristic of the decompression time, the decompression time from the maximum pressure to, for example, the first stop pressure is relatively short, about several minutes, and in particular, the decompression step from the first stop pressure to the atmospheric pressure requires several hours. This tendency varies depending on the maximum pressure and the working time in the environment, but the tendency is almost the same.

Focusing on this point, in the present invention, in an environment where the space is relatively narrow but the decompression time is short, a small and sturdy man-ventilation chamber is used, and the decompression time is long. For the environment after 1 stop pressure, by using another man's air chamber that includes the above man's air chamber, which is made of reinforced concrete and has a large space, measures to prevent high pressure obstacles for workers can be achieved. The thickness of the reinforced concrete member of the upper slab has been reduced.

FIG. 1 shows a first embodiment of the present invention.

In the figure, reference numeral 1 denotes a pneumatic caisson, the caisson body is provided with a tubular side wall 2, a lower portion of the side wall 2 is a blade edge 3, and a ceiling slab 4 is provided below the side wall 2. ing. G is the ground to be excavated. Then, the working room 5 is composed of the ground G, the ceiling slab 4, and the cutting edge 3.

An opening 6 is formed in a part of the ceiling slab 4 so as to penetrate the work room 5 and the upper space of the ceiling slab 4 so that an operator can enter and exit the work room 5, and the ceiling is above the opening 6. The first man's air chamber 7 is provided above the slab 4. The chamber of the first man air chamber 7 functions as a first pressurizing / depressurizing unit.

A first hatch 8 that can be opened and closed is provided at the lower part of the first man air chamber 7. The first hatch 8 is provided above the opening 6. Further, a second hatch 9 that can be opened and closed is also provided on the side of the first man air chamber 7.

The first hatch 8 is for opening and closing to allow an operator to enter and exit the work room 5. The second hatch 9 is for an operator to enter and exit the space portion in the first man air chamber 7 and on the ceiling slab 4.

Reference numeral 10 denotes an upper slab provided above the ceiling slab 4 via an interval, and the space portion between the upper slab 10 and the ceiling slab 4 becomes the second man air chamber 11, and the second man air chamber 11 is the second man air chamber 11. 2 Functions as a pressurizing / depressurizing unit. The second man's air chamber 11 is made of reinforced concrete, for example, and is partitioned by the ceiling slab 4, the upper slab 10, and the side wall of the caisson body 2, and the ankles, knees, hips, and back are extended to avoid a cramped posture. It is a space where

As described above, in the present invention, the first and second man-shelter chambers 7 and 11 are provided to prevent health problems of workers and prevent the thickness of the upper slab 10 from increasing. This will be described later.

Reference numeral 12 denotes a man shaft for workers to enter and exit the work room 5 from the ground, penetrating the upper slab 10, and the lower portion is provided above the ceiling slab 4. As is well known, a spiral staircase or an elevator (not shown) is provided in the man shaft 12, and a third hatch 13 that can be opened and closed is provided in a portion of the second man air chamber 11, and work from the ground is provided. A person can enter the first man's spiral chamber 7 via the second man's spiral chamber 11 via the second hatch 9. On the contrary, the worker in the work room 5 enters the first man air pressure chamber 7 via the first hatch 8, and after a predetermined time elapses, enters the second man air pressure room 11 via the second hatch 9. After spending a predetermined time, the third hatch 13 can be opened and closed to go out to the ground via the man shaft 12 in an atmospheric pressure environment.

Next, the method of setting the atmospheric pressure condition of each part of the pneumatic caisson according to the present invention will be described in detail.

The present invention constitutes a double man's air chamber consisting of a first man's air chamber 7 and a second man's air chamber 11, and a pressure division is provided by these two pressurizing / depressurizing portions to prevent high pressure damage. I am trying to do it.

When the atmospheric pressure in the working room 5 is set to, for example, 0.7 MPa as the condition setting of the atmospheric pressure, the maximum pressure of the pressurizing / depressurizing portion of the second man's air pressure chamber 11 is set to, for example, 0.21 MPa, and in addition to this, the atmospheric pressure on the ground is 3 The atmospheric pressure status of the division is set.

It should be noted that the material equipment, etc. related to excavation in the excavator constituting the pneumatic caisson method and the loading and unloading of excavated soil are not directly related to the gist of the present invention, and since they are well known, the notation and explanation of the figures are omitted. To do.

As described above, the present invention includes man air chambers 7 and 11 having a first and second double structure, and the first man air chamber 7 is a second man air chamber 11 made of reinforced concrete or the like. The inside of the first man air chamber 7 is the first pressurizing / depressurizing unit, and the inside of the second man air chamber 11 is the second air pressure / depressurizing unit. In this case, the internal pressure of the first man's air chamber 7 is made durable because the air pressure in the work chamber acts on it, and the second man's air chamber 11 in a wide space is set to a low pressure.

That is, in the first pressurizing / depressurizing section of the first man air chamber 7, the pressure is adjusted by a pressurizing / depressurizing device (not shown: pressurizing valve, depressurizing valve, pressure monitoring panel, etc.), and the air pressure in the working chamber is 0.7 MPa. The pressure state is set to 1 stop pressure, and the pressurization / depressurization section of the 2nd man air chamber 11 is similarly adjusted by the pressurization / depressurization device to obtain a pressure state from the 1st stop pressure to atmospheric pressure, for example, 0.21 MPa to 0. It is configured as follows.

As described above, in the conventional case, there was only one pressurizing / depressurizing section, but in the first embodiment of the present invention, when the air pressure in the working room 5 is 0.7 MPa, for example, the first pressurizing / depressurizing section 0 The range of 0.7 to 0.21 MPa, the pressurizing / depressurizing section of the second man air chamber 11 is lower than that, and the range of 0.21 MPa to 0 is set, and the feature is that there are a plurality of pressurizing / depressuring sections.

This allows workers to perform decompression work step by step and efficiently, reducing the burden on workers who have to stay in one decompression chamber for a long time at high pressure as in the past, and a good environment. To relieve the mental distress of workers and eliminate health problems.

In addition, the pressure resistance of the upper slab 10 is increased by lowering the air pressure of the second man air chamber 11 between the ceiling slab 4 and the upper slab 10 by the first air chamber 7 so that the air pressure acts on the upper slab 10. It is not necessary to increase the property as in the past, and the member thickness of the upper slab 10 can be reduced.

FIG. 2 shows a second embodiment of the present invention.

In this embodiment, the upper slab is formed by the upper slab 10A having a smaller area than the ceiling slab 4 and located above the ceiling slab 4, and the upper slab side walls 17A and 17B formed on the outer periphery of the upper slab 10A. It is characterized in that a closed second man air chamber 11 is formed in the upper part of No. 4.

It is the same as the first embodiment in that the lower part of the man shaft 12 having the first man air chamber 7 and the hatch 13 is provided in the second man air chamber 11.

FIG. 3 shows a third embodiment of the present invention.

In this embodiment, the upper slab 10B is provided with a side wall 17A having a sixth hatch 16, and the man shaft 12 is connected to the hatch 16 of the side wall 17A. In this embodiment, the upper slab 10B is made smaller than the floor area of the ceiling slab 4, and a side wall 17A having a hatch 16 that can be opened and closed is provided between the outer circumference of the upper slab 10B and the ceiling slab 4, and the side wall 17A is provided with a man. The shaft 12 is connected. The lower portion of the man shaft 12 is provided in the space between the side wall 17A and the side wall of the caisson body 2.

FIG. 4 shows a fourth embodiment of the present invention.

This embodiment is applied to a relatively small-scale pneumatic caisson construction method, and is a modification of the third embodiment shown in FIG. 3, in which the lower part of the man shaft 12 is connected to the upper part of the first man air chamber 7. , Space saving. A hatch 14 is provided at the lower part of the man shaft 12 so that the man shaft 12 can freely enter and exit the first man air chamber 7. Upon depressurization, the operator initially depressurizes in the first man's air chamber 7 provided on the ceiling slab 4, decompresses to the first stop pressure, and then moves to the second man's air chamber 11 to reduce the pressure. When the next worker enters during decompression, he / she enters the work room 5 through the first man air chamber 7. At that time, the hatch 9 is closed. Other configurations are the same as those of the first embodiment shown in FIG. 1, and the same members are indicated by the same reference numerals, and the description thereof will be omitted.

FIG. 5 shows a fifth embodiment of the present invention.

This embodiment is a modification of the fourth embodiment shown in FIG. 4, and the third man air chamber 7A is laminated and connected to the upper part of the first man air chamber 7 included in the second man air chamber 11. Further, the fourth man's air chamber 7B is laminated and connected to the upper part of the third man's air chamber 7A. The man shaft 12 penetrating the upper slab 10B is connected to the uppermost fourth man air chamber 7B. A hatch for entering and exiting the fourth man's air chamber is provided at the lower part of the man shaft 12. In addition, a hatch will be provided in each man's room. The stacking mode may be two or three or more.

Upon depressurization, the operator initially depressurizes in the first man's air chamber 7 provided on the ceiling slab 4, decompresses to the first stop pressure, and then moves to the second man's air chamber 11 to reduce the pressure. When the next worker enters during decompression, he / she enters the work room 5 through the 4th man air chamber 7B, the 3rd man air chamber 7A, and the like. If the previous worker enters during decompression and the later worker leaves, the hatch 8 is closed to close the second man's air pressure chamber 11, the first man's air pressure chamber 7, and the capsule-shaped third man's air pressure chamber. If the air pressure is the same between 7A, the previous decompression worker moves to the capsule-shaped third man air chamber 7A and continues decompression. Later workers move to the second man's air chamber 11 to reduce the pressure after the initial decompression is performed in the first man's air chamber 7 and the pressure is reduced to the first stop pressure. At this time, if the worker who is decompressing earlier enters the work room during decompression in the third man air pressure chamber 7A, the later worker pressurizes in the fourth air pressure chamber 7B. When the pressure becomes the same as that of the third air chamber 7A during decompression, the former worker and the latter worker are replaced, and the destination worker continues to decompress in the fourth air chamber 7B until the atmospheric pressure becomes atmospheric pressure. Leave the room on the ground. The latter worker moves to the work room after continuing to pressurize in the third air chamber 7A.

In addition, the 1st, 3rd, and 4th man air chambers and the 2nd man air chamber in the above-described embodiment may be man air chambers made of precast members depending on the scale and shape of the structure.

Further, the precast member may be composed of a single member such as a steel plate, a steel frame, or a reinforced concrete or a composite member thereof, which facilitates assembly and disassembly.

1 Pneumatic caisson 2 Caisson body 3 Blade edge 4 Ceiling slab 5 Work room 6 Opening 7 1st man air chamber 7A 3rd man air chamber 7B 4th man air chamber 8 1st hatch 9 2nd hatch 10, 10A, 10B, 10'Upper slab 11 2nd man caisson 12 Man shaft 13 3rd hatch 14 4th hatch 16 5th hatch 17 Side wall

Claims (7)

A pneumatic caisson with a double slab structure that generates a high-pressure working environment that changes from the atmospheric pressure on the ground to the pressure in the work room and has a ceiling slab and an upper slab. A first-man air chamber that allows entry and exit is provided, and the space between the ceiling slab and the upper slab is used as a second man air chamber that includes the first man air chamber, and the first man air chamber is the first. has one pressure regulating unit, the second man air閘室has a second pressurizing and depressurizing portion, both between will allow out through the hatch, the first from the working chamber of the pressure, the second man air閘室is The first man air chamber on which the pressure in the work chamber acts can be sequentially set to be low, and the first man air chamber is a pressure-resistant member, and the upper slab of the second man air chamber whose pressure is lower than that of the first man air chamber. Pneumatic caisson characterized by thinning the member thickness of. The pneumatic caisson according to claim 1, wherein a lower portion of a man shaft is provided in the second man-shelter chamber so as to penetrate the upper slab. In the pneumatic caisson according to claim 1, the upper slab is smaller than the floor area of the ceiling slab, a side wall is provided between the end of the upper slab and the ceiling slab, and the side wall and the side wall of the caisson body are connected to each other. A pneumatic caisson characterized by a space between them. The pneumatic caisson according to claim 3, wherein a lower portion of the man shaft is provided in the space portion, and the man shaft is connected to an openable and closable hatch provided on the side wall. The pneumatic caisson according to claim 1, wherein a man shaft penetrating the upper slab is connected to the first man air chamber. In the pneumatic caisson according to claim 1, at least one or more man air chambers are connected in a laminated manner to the upper part of the first man air chamber, and each man air chamber has a different air pressure and is via a hatch. A pneumatic caisson that is accessible and features a man shaft connected to the man's air pressure chamber at the top. A pneumatic caisson with a double slab structure that generates a high-pressure working environment that changes from the atmospheric pressure on the ground to the pressure in the work room and has a ceiling slab and an upper slab. A first man's caisson room that allows entry and exit is provided, and the space between the ceiling slab and the upper slab is used as a second man's caisson room that includes the first man's caisson room, and the first man's caisson room is the first. It has a 1 pressurizing / depressurizing unit, and the 2nd man's air chamber has a 2nd air pressure / depressurizing unit, and both can be accessed via a hatch, and the 1st and 2nd man's air chambers can be accessed from the pressure in the working chamber. In the method of setting the pressure conditions of the work room and the man's air chamber of this pneumatic caisson, an openable and closable hatch that allows entry and exit between the ceiling slab and the upper slab is provided. The pressure conditions of the pneumatic caisson work room and the man air chamber are characterized in that the man air chambers that have and have a pressurizing / depressurizing part are further expanded, and the air pressures of each man air chamber are set to be different in sequence. Setting method.

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