Caisson shovel, excavation equipment and pneumatic caisson method

Abstract

To provide a caisson shovel capable of improving excavation efficiency in a hard ground without detaching an attachment such as a breaker under a pneumatic pressure by a pneumatic caisson method, to provide excavation equipment, and to provide the pneumatic caisson method.SOLUTION: A caisson shovel 101 used in a high pressure work chamber of a pneumatic caisson method includes: a bucket 152 (bucket part 154) on which sediment is loaded; and a plurality of claw parts 155 for loosening the ground by protruding from the bucket 152 and penetrating the ground. A tip 152a of the bucket 152 and a base end of the plurality of claw parts 155 are aligned in a straight line-like manner, and the same load soil amount as that of a normal bucket is secured. Out of the plurality of claw parts 155, at least one claw part is longer than other claw parts, it becomes a sharp long claw 156 in which the width is narrower toward the tip and which is pointed in a wedge shape, and the long claw 156 is rigidly connected to the bucket 152.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a caisson shovel, an excavation facility, and a pneumatic caisson construction method. [Background technology]

[0002] Conventionally, the pneumatic caisson method, which can secure a vast space underground, has been used to construct bridge foundations, underground tunnels, underground structures, etc., found in the construction of transportation infrastructure. The pneumatic caisson method is a construction method in which a square cylindrical reinforced concrete box with a bottom called a caisson is constructed, compressed air pressure is pumped into a high-pressure work chamber to balance the groundwater pressure, preventing groundwater infiltration, and an excavator with a caisson shovel (hereinafter simply referred to as a caisson excavator) is used to excavate the ground surface below the base plate, and the caisson itself is lowered to secure space for constructing a structure underground.

[0003] This type of pneumatic caisson method involves excavation in a dry environment, preventing groundwater from seeping in. However, when excavation work is performed using a manned excavator, there is a risk of the worker developing decompression sickness when the pressure is reduced from the high-pressure work chamber below the caisson base to atmospheric pressure, making it dangerous.

[0004] Therefore, in recent years, the mainstream method of pneumatic caisson construction has been to operate a caisson excavator remotely from the ground to perform excavation work. There are also attempts to go further and automate the method, with the caisson excavator operating automatically.

[0005] However, the ground to be excavated by the caisson shovel of the caisson excavator varies, and there is a problem that excavation is difficult when the ground is hard. In particular, when excavating hard ground such as soft rock or clay using a caisson shovel equipped with a standard bucket, the bucket claws do not penetrate the ground deeply enough to loosen the ground, so the amount of soil loaded into the bucket is small, making it inefficient. To address this problem, the conventional procedure was to attach an attachment such as a breaker to the caisson shovel, break (loosen) the ground in advance, and then replace the bucket and load and discharge the soil. This meant that it took time to attach and remove the attachment in the high-pressure work chamber, making it difficult to excavate efficiently.

[0006] On the other hand, Patent Document 1 discloses a bucket that is attached to and used with construction machinery such as a power shovel or a wheel loader, in which one or more of a plurality of excavation claws at the tip of the bucket protrude further forward than the other excavation claws in order to adjust the amount of excavation depending on the hardness of the ground to be excavated, and the excavation claws are freely detachable from the bucket (see claims 1 and 4 in the claims of Patent Document 1, paragraphs

[0020] to

[0032] in the specification, Figures 1 and 2 in the drawings, etc.).

[0007] The bucket described in Patent Document 1 is said to be able to easily crush even solid objects such as concrete or asphalt because a large force acts on the protruding excavation claws, thereby significantly increasing the excavation force. However, the bucket described in Patent Document 1 is attached to a stand-alone construction machine such as a power shovel, and is also designed on the premise that the excavation claws will be replaced depending on the object to be excavated.

[0008] For this reason, if applied directly to a caisson excavator, as with the above-mentioned attachment, it is necessary for a worker to descend into the high-pressure work room in which the caisson excavator is remotely operated to replace the excavation claws, and there is a problem that it takes a long time to adapt to atmospheric pressure when depressurizing, resulting in extremely poor work efficiency. It is possible to use the excavation claws without replacing them, but since the excavation claws are removable by fitting, there is a risk that the excavation claws may come off depending on how they are used, and if they do come off, a worker must enter the high-pressure work room, which not only takes a long time but also has a negative impact on safety.

[0009] In addition, the bucket described in Patent Document 1 has a part of the tip of the bucket protruding, creating a gap between the bucket and the ground, so that the amount of soil that can be loaded into the bucket in one sweep is small. Therefore, when this is applied to a pneumatic caisson construction method in which multiple caisson excavators work together to move excavated soil down a material shaft and transport it away, there is a problem that excavation efficiency is reduced.

[0010] Furthermore, Patent Document 2 discloses an asphalt cutting uneven layer peeling blade device having a scraper attached to comb-shaped teeth (claws) on the bucket of a power shovel (see claim 1 in the claims of Patent Document 2, paragraphs

[0014] to

[0027] of the specification, and Figures 1 and 2 of the drawings, etc.).

[0011] The asphalt cutting uneven layer peeling blade device described in Patent Document 2 is said to have good bite into the asphalt and can peel it off easily. However, the asphalt cutting uneven layer peeling blade device described in Patent Document 2 was not applicable to a caisson excavator. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2018-115533 A [Patent Document 2] Utility Model Registration No. 3228483 Summary of the Invention [Problem to be solved by the invention]

[0013] Therefore, the present invention has been devised in consideration of the above-mentioned problems, and its object is to provide a caisson shovel, excavation equipment, and pneumatic caisson construction method that can improve excavation efficiency in hard ground without detaching attachments such as breakers under pressurized air using the pneumatic caisson construction method. [Means for solving the problem]

[0014] The caisson shovel of claim 1 is a caisson shovel used in a high-pressure workroom of a pneumatic caisson construction method, and is equipped with a bucket for loading soil and a number of claws that protrude from the bucket and penetrate into the ground to loosen it, the tip of the bucket and the base ends of the number of claws are aligned in a straight line to ensure the same soil loading capacity as a normal bucket, and at least one of the number of claws near the center is longer than the other claws and is a sharp, wedge-shaped claw that narrows in width toward the tip, and the long claw is rigidly connected to the bucket.

[0015] The excavation equipment of claim 2 is an excavation equipment used in a pneumatic caisson construction method for excavating ground, and is characterized in that it comprises a plurality of caisson shovels, some of which are the caisson shovel described in claim 1.

[0016] The pneumatic caisson construction method of claim 3 is a pneumatic caisson construction method for building underground structures by lowering a caisson, which is a bottomed box made of reinforced concrete, into the ground, and is characterized in that it is equipped with the excavation equipment described in claim 2, and uses the caisson shovel described in claim 1 to penetrate the long claws deep into the hard ground to loosen the hard ground, then forms a pile of soil from the ground loosened by the caisson shovel, and uses another caisson shovel of the excavation equipment to scoop up and move the soil from the pile of soil and remove it.

[0017] The pneumatic caisson construction method of claim 4 is characterized in that, in the third invention, the caisson shovel described in claim 1 is used to scoop up and move soil from a pile of soil formed by another caisson shovel of the excavation equipment, and then remove the soil. Effect of the Invention

[0018] According to the first to fourth inventions, at least one of the multiple claws of the caisson shovel is a long, sharp claw that narrows toward the tip, and the long claw is rigidly connected to the bucket, so there is no need to attach or detach an attachment such as a breaker under the compressed air of the pneumatic caisson construction method. Also, according to the inventions of claims 1 to 4, the tip of the bucket and the base ends of the multiple claws are aligned in a straight line, ensuring the same soil loading capacity as a normal bucket, so that after the long claw of the caisson shovel loosens hard ground, the loosened soil can be moved using the caisson shovel as it is, improving excavation efficiency in hard ground.

[0019] In particular, according to the fourth invention, the caisson shovel described in claim 1 is used to scoop up, move, and remove soil from a pile of soil formed by another caisson shovel of the excavation equipment, so that the caisson shovel described in claim 1 with long claws can be effectively utilized even when the ground to be excavated is not hard, and excavation efficiency can be improved when hard ground is encountered. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing an example of main equipment for a pneumatic caisson construction method in which a caisson shovel according to an embodiment of the present invention is used. [Diagram 2] FIG. 2 is a perspective view showing a caisson shovel according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a photograph showing a caisson shovel according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a photograph showing a caisson shovel according to the second embodiment of the present invention. [Diagram 5] FIG. 5 is a photograph showing a caisson shovel according to the third embodiment of the present invention. [Figure 6] FIG. 6 is a photograph showing a caisson shovel according to the fourth embodiment of the present invention. [Figure 7] Figure 7 is a photograph showing the length of the long jaws of the above-mentioned caisson shovel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of a caisson shovel and a pneumatic caisson construction method according to the present invention will be described in detail with reference to the drawings.

[0022] [Major caisson equipment] First, the main equipment used in the pneumatic caisson construction method according to the embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the main equipment of the pneumatic caisson construction method in which a caisson shovel according to the embodiment of the present invention is used.

[0023] As shown in Figure 1, the pneumatic caisson method is a method for constructing underground structures by lowering a caisson 1, a bottomed rectangular cylindrical box made of reinforced concrete, into the ground using excavation equipment E1, rigging equipment E2, soil removal equipment E3, air supply equipment E4, and standby / safety equipment E5.

[0024] The excavation equipment E1 includes, for example, a plurality of caisson excavators (hereinafter referred to as caisson shovels 100), an automatic soil loading device 11, and a ground remote control room 13. The caisson shovels 100 (101-104) are installed in a high-pressure work chamber 2 located below the bottom plate of the caisson 1. In addition, the excavation equipment E1 is a caisson shovel 101 according to the first embodiment, in which a portion (at least one) of the plurality of caisson shovels 100 has a long claw 156 described below.

[0025] Moreover, the automatic earth loading device 11 loads earth excavated by the caisson shovel 100 (caisson shovel 101) into a cylindrical earth bucket 31. The ground remote operation room 13 is equipped with a remote operation device 12 that remotely controls the operation of the caisson shovel 100 (caisson shovel 101) from the ground.

[0026] The outfitting facility E2 comprises, for example, a manshaft 21, a manlock 22 (airlock), a material shaft 23, and a material lock 24 (airlock). The manshaft 21 is a cylindrical passageway connecting the ground to the high-pressure work chamber 2 so that workers can enter and exit the high-pressure work chamber 2, and is provided with, for example, a spiral staircase 25. The manlock 22 is an airtight door with a double door structure that is provided in the manshaft 21 and adjusts the pressure difference between the atmospheric pressure on the ground and the pressure inside the high-pressure work chamber 2.

[0027] The material shaft 23 is a cylindrical passageway connecting the ground and the high-pressure work chamber 2 mainly for transporting the earth bucket 31 loaded with soil by the automatic soil loading device 11 to the ground, and serves as a material transport path for transporting materials in and out. The material lock 24 is an airtight door with a double door structure provided in the material shaft 23 to adjust the pressure difference between the atmospheric pressure on the ground and the pressure inside the high-pressure work chamber 2. The man lock 22 and the material lock 24 are configured to suppress changes in the air pressure inside the high-pressure work chamber 2, allowing workers and the earth bucket 31 to enter and exit the high-pressure work chamber 2.

[0028] The soil removal equipment E3 includes, for example, an earth bucket 31, a carrier device 32, and a soil hopper 33. The earth bucket 31 is a cylindrical container with a bottom into which soil excavated by the caisson shovel 100 (caisson shovel 101) is loaded. The carrier device 32 is a device that pulls up the earth bucket 31 to the ground via the material shaft 23 and carries it away. The soil hopper 33 is a facility that temporarily stores the soil carried to the ground by the earth bucket 31 and the carrier device 32.

[0029] The air supply equipment E4 includes, for example, an air compressor 42, an air purifier 43, an air supply pressure regulator 44, and an automatic pressure reducing device 45. The air compressor 42 is a device that sends compressed air into the high-pressure work chamber 2 through the air supply pipe 41 and the air supply path 3 formed in the caisson 1. The air purifier 43 is a device that purifies the compressed air sent by the air compressor 42. The air supply pressure regulator 44 is a device that adjusts the amount (pressure) of compressed air sent from the air compressor 42 into the high-pressure work chamber 2 so that the air pressure in the high-pressure work chamber 2 is approximately equal to the groundwater pressure. The automatic pressure reducing device 45 is a device that reduces the air pressure in the manlock 22.

[0030] The standby / safety equipment E5 includes, for example, an emergency air compressor 51 and a hospital lock 53. The emergency air compressor 51 is a device that can send compressed air into the high-pressure work chamber 2 in place of the air compressor 42 when the air compressor 42 breaks down or is under inspection. The hospital lock 53 is a decompression chamber into which a worker who has worked in the high-pressure work chamber 2 enters to gradually acclimate his or her body to atmospheric pressure.

[0031] [Caisson excavator] Next, a caisson shovel 100, which is a conventional caisson excavator, will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the conventional caisson shovel 100.

[0032] As shown in Fig. 2, the caisson excavator 100 includes a traveling body 110, a boom 130, and a bucket attachment 150. The traveling body 110 is attached to a pair of left and right traveling rails 4 provided on the ceiling of the high-pressure work chamber 2, and travels along the traveling rails 4 while suspended from the left and right traveling rails 4. The boom 130 is pivotally connected to a rotating frame 121 of the traveling body 110 so as to be swingable up and down. The bucket attachment 150 is attached to the tip of the boom 130.

[0033] The traveling body 110 includes a traveling frame 111, a swivel frame 121, and traveling rollers 113. The swivel frame 121 is provided on the underside of the traveling frame 111 so as to be able to rotate freely. The traveling rollers 113 are four rollers provided on the front, rear, left and right sides of the upper surface of the traveling frame 111. The traveling body 110 is configured to travel along the left and right traveling rails 4 by rotating the front, rear, left and right traveling rollers 113.

[0034] The boom 130 comprises a base end boom 131, a tip boom 132, a telescopic cylinder 133, and a hoisting cylinder 134. The base end boom 131 is attached to the swivel frame 121 so as to be freely raised and hoisted (freely swingable up and down). The tip boom 132 is combined with the base end boom 131 in a nested manner and is configured to be freely projected and retracted. The telescopic cylinder 133 is provided inside the base end boom 131. Two hoisting cylinders 134 are provided on the left and right of the base end boom 131. The boom 130 is configured so that when the telescopic cylinder 133 is extended or retracted, the tip boom 132 moves in the longitudinal direction relative to the base end boom 131, thereby extending or retracting the boom 130. The base ends of the pair of hoisting cylinders 134 are rotatably attached to the left and right sides of the base end boom 131, respectively.

[0035] The bucket attachment 150 includes a base member 151, a bucket 152, and a bucket cylinder 153. The base member 151 is attached to the tip boom 132. The bucket 152 is attached to the tip of the base member 151 so as to be able to swing up and down. The bucket cylinder 153 is configured so that the bucket 152 can swing up and down with respect to the base member 151.

[0036] <bucket> Next, the bucket 152, which is a characteristic part of the caisson shovel 101 according to the first embodiment of the present invention, will be described in more detail with reference to Figures 3 to 7. Figure 3 is a photograph showing the caisson shovel 101 according to the first embodiment of the present invention. The caisson shovel 101 according to the first embodiment differs from the conventional caisson shovel 100 in the claw portion of the bucket 152, so this point will be described and other explanations will be omitted.

[0037] As shown in FIG. 3, this bucket 152 comprises a bucket portion 154 for loading soil and a number of claw portions 155 that protrude from the bucket and penetrate into the ground to loosen it, and the tip 154a of this bucket portion 154 and the base ends of the number of claw portions 155 are aligned in a straight line, ensuring the same soil loading capacity as a normal bucket.

[0038] Here, the term "the same load amount as a normal bucket" refers to the bucket capacity of the standard bucket 152 of the conventional caisson shovel 100 defined by the JIS standard according to the capacity of the caisson shovel 101, and generally refers to the "piled capacity" which is the capacity of a heap when excavated material is piled up in the bucket at a 1:1 gradient from the upper edge of the bucket. In other words, "ensuring the same load amount as a normal bucket" refers to the bucket part 154 excluding the claw part 155 having the same shape as the normal standard bucket 152, and the "piled capacity" being approximately the same volume.

[0039] As shown in Fig. 3, the caisson excavator 101 according to the first embodiment has a central claw 156 among the multiple claws 155, which is longer than the other claws 155 and has a sharp, wedge-shaped pointed claw 156 that narrows toward the tip. Therefore, when the base end boom 131 and the tip boom 132 are extended and the claw 156 is pushed into the ground, the claw 156 can easily penetrate up to the base end of the claw 156 even if the ground is hard, such as soft rock or clay. Therefore, the length of the claw 156 can be used to generate a moment using the principle of leverage to break up (loosen) the ground.

[0040] Also, unlike the case where an attachment such as a breaker is attached to a conventional caisson shovel, there is no need to attach or detach an attachment such as a breaker inside the high-pressure work chamber 2. Therefore, the caisson shovel 101 according to the first embodiment can solve the problem that it takes time to attach and detach an attachment, making it difficult to perform excavation efficiently. Moreover, since the worker does not enter the high-pressure work chamber 2, the risk of caisson sickness can be reduced.

[0041] Furthermore, the long claws 156 are attached so that the width direction X is perpendicular to the side of the tip 152a of the bucket 152. They are joined so that the width direction X of the long claws 156 is in the direction in which high stress acts when the long claws 156 that have been thrust into hard ground are pried to generate a moment. For this reason, the long claws 156 of the caisson excavator 101 according to the first embodiment are able to withstand high stress while keeping the plate thickness of the long claws 156 thin.

[0042] The long jaw 156 is made of a steel plate having the same strength as the bucket 152, and is rigidly connected to the tip 152a of the bucket 152 by full penetration welding. Of course, the connection between the long jaw 156 and the bucket 152 is not limited to welding, and may be mechanically connected with bolts or the like. However, the connection between the long jaw 156 and the bucket 152 must be rigidly connected by, for example, joining with a one-way bolt or a locking nut, or by welding after bolting, rather than by fitting, so that work such as retightening does not need to be performed in the high-pressure working chamber 2. Here, rigid connection refers to a connection that allows the bending moment to be transmitted from the long jaw 156 to the bucket 152 to be approximately 100%.

[0043] Also, instead of making the central claw portion 155 a long claw 156 as shown in Fig. 3, the central three claw portions 155 may be long claws 156 as shown in Fig. 4, or all five claw portions 155 may be long claws 156 as shown in Fig. 5. Of course, the number of claw portions 155 is not limited to five, and more claw portions may be provided. Fig. 4 is a photograph showing a caisson shovel 102 according to a second embodiment of the present invention, and Fig. 5 is a photograph showing a caisson shovel 103 according to a third embodiment of the present invention.

[0044] Next, a long claw 156' according to a modified example of the long claw 156 described above will be described with reference to Figs. 6 and 7. Fig. 6 is a photograph showing a caisson shovel 104 according to a fourth embodiment of the present invention, and Fig. 7 is a photograph showing the length of the long claw 156' of the caisson shovel 104. Note that the caisson shovel 104 according to the fourth embodiment differs from the caisson shovel 103 according to the third embodiment described above in that the long claw 156 having a width direction X in the up-down direction is replaced with a long claw 156' having a width direction Y in the lateral direction, and therefore this point will be described and other explanations will be omitted.

[0045] As shown in Figures 6 and 7, the width direction Y of the long claw 156' of the caisson shovel 104 according to the fourth embodiment is the horizontal direction along the tip 152a side of the bucket 152. Since the direction in which high stress acts is not the wide direction of the base end of the long claw 156', the cross section of the base end of the long claw 156' is a rectangular cross section close to a square, and a large amount of steel is used per long claw 156'. However, even in this case, it is clear that the long claw 156' exhibits the same function as the long claw 156.

[0046] As shown in Fig. 7, the length of the long claw 156' is preferably 30 cm or more. This is because it is advantageous to use the length of the long claw 156' to generate a moment using the principle of leverage to loosen hard ground. However, from the standpoint of strength, it is preferable that the length of the long claw 156' be shorter than the overall length of the bucket 152. Of course, the same applies to the long claw 156 described above.

[0047] [Pneumatic caisson construction method] Next, a pneumatic caisson construction method according to an embodiment of the present invention will be described. As described above, the pneumatic caisson construction method according to this embodiment is a construction method for constructing an underground structure by sinking a caisson 1, which is a bottomed rectangular cylindrical box made of reinforced concrete, into the ground using an excavation equipment E1, an outfitting equipment E2, an earth removal equipment E3, an air supply equipment E4, and a standby / safety equipment E5. However, the pneumatic caisson construction method according to the embodiment differs from a conventional pneumatic caisson construction method in that a part (at least one) of the multiple caisson shovels 100 of the excavation equipment E1 is a caisson shovel 101 having a long claw 156, and in the method of using the caisson shovel. Therefore, only this point will be described and other explanations will be omitted.

[0048] In the pneumatic caisson method according to this embodiment, some of the multiple caisson shovels 100 of the excavation equipment E1 are caisson shovels 101 with long jaws 156, so when hard ground such as soft rock or clay appears in the ground to be excavated, the caisson shovel 101 travels on the traveling rails 4 and moves to the vicinity of the hard ground. Then, the long jaws 156 of the caisson shovel 101 are penetrated deep into the hard ground, and the hard ground is excavated and loosened using the principle of leverage, and then a pile of soil is formed from the loosened ground by the same caisson shovel 101. After that, the other multiple caisson shovels 100 of the excavation equipment E1 work together to scoop up soil from the pile of soil, move to the vicinity of the earth bucket 31 directly below the material shaft 23, and use the soil removal equipment E3 to remove the soil.

[0049] At this time, since the long jaws 156 are rigidly connected in advance to the bucket 152 of the caisson shovel 101, not only is it not necessary to attach and detach attachments such as breakers inside the high-pressure work chamber 2 as in the conventional pneumatic caisson construction method, but there is also very little risk of the long jaws 156 coming off. Also, since the bucket portion 154 of the caisson shovel 101 has the same soil carrying capacity as the normal bucket of the conventional caisson shovel 100, it is possible to improve excavation efficiency in hard ground.

[0050] Furthermore, in the pneumatic caisson method according to this embodiment, even if the ground to be excavated does not contain hard ground, the caisson shovel 101 cannot remove the long claws 156, but since the same loadable soil volume as that of a normal bucket is ensured, the caisson shovel 101 and the caisson shovel 100 cooperate to scoop up soil from the pile of soil formed by the caisson shovel 100 of the excavation equipment E1, move to the vicinity of the earth bucket 31 immediately below the material shaft 23, and discharge the soil using the soil discharge equipment E3. Therefore, excavation and soil discharge work can be performed efficiently regardless of the type of ground to be excavated.

[0051] According to the caisson shovels 101-104, excavation equipment E1 and pneumatic caisson construction method of the embodiments of the present invention described above, there is no need to attach and detach attachments such as breakers inside the high-pressure work chamber 2, and excavation efficiency in hard ground can be improved.

[0052] The caisson shovels 101-104, the excavation equipment E1, and the pneumatic caisson construction method according to the embodiments of the present invention have been described in detail above. However, the above-mentioned or illustrated embodiments are merely examples of embodiments embodied in carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these. [Explanation of symbols]

[0053] 1: Caisson 2:Workroom 3: Air supply path 4: Running rail E1: Drilling equipment 11: Automatic soil loading device 12: Remote control device 13: Ground remote control room E2: Outfitting equipment 21: Manschaft 22: Manrock 23: Material shaft 24: Material Rock 25: Spiral staircase E3:Earth removal equipment 31: Earth Bucket 32: Carrier device 33: Sand hopper E4: Air supply equipment 41: Air pipe 42: Air compressor 43: Air purifier 44: Air supply pressure adjustment device 45: Automatic pressure reducing device E5:Safety equipment 51: Emergency air compressor 53: Hospital Rock 100~104: Caisson shovel (caisson excavator) 110: Running vehicle 111: Running frame 113: Travel roller 121: Swivel frame 130: Boom 131: Base boom 132: Tip boom 133: Telescopic cylinder 134: Undulating cylinder 150: Bucket attachment 151: Base material 152: Bucket 152a: Tip 153: Bucket cylinder 154: Bucket section 155: Claw part 156,156': long nails

Claims

1. A caisson shovel used in a high-pressure work chamber for the pneumatic caisson construction method, The present invention is provided with a bucket for loading soil and a plurality of claws for loosening the ground by protruding from the bucket and penetrating the ground, The tip of the bucket and the base ends of the multiple claws are aligned in a straight line to ensure the same load capacity as a normal bucket, At least one of the plurality of claw portions is longer than the other claw portions and is a sharp, wedge-shaped long claw whose width narrows toward its tip, The long claw is rigidly connected to the bucket. This caisson excavator is characterized by:

2. An excavation facility used in the pneumatic caisson method for excavating ground, A plurality of caisson shovels are provided, and a part of the plurality of caisson shovels is the caisson shovel according to claim 1. The drilling equipment comprises:

3. This is a pneumatic caisson construction method in which a caisson, a bottomed box made of reinforced concrete, is lowered into the ground to build an underground structure. The drilling equipment according to claim 2, The caisson shovel according to claim 1 is used to penetrate the long claws deep into the hard ground to loosen the hard ground, and then a pile of soil is formed from the loosened ground by the caisson shovel, and another caisson shovel of the excavation equipment is used to scoop up and move the soil from the pile of soil and remove it. This is a pneumatic caisson construction method characterized by the following.

4. The caisson shovel according to claim 1 is used to scoop up and move soil from a pile of soil formed by another caisson shovel of the excavation equipment, and to remove the soil. The pneumatic caisson construction method according to claim 3, characterized in that

Images