JPH09177462A - Method to drill sediment layer and bedrock and device to drill sediment layer and bedrock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and speedily carry out construction work from a sediment layer to a bedrock. SOLUTION: A segment layer to a bedrock continuing from the segment layer below it are dug out by a device furnished with a function to inject fluid with high pressure from a head end downward and provided with a rotating drill bit for rock drilling 2 a diameter of which is larger than a down hammer 1 and to drill by rotation on an upper part of the down hammer 1 to drill a bedrock by vertical movement. At the time of digging the segment layer, the segment layer is dug out by drilling and digging below the down hammer 1 while injecting fluid with high pressure from the head end of the down hammer land by rotating the rotating drill bit for rock drilling 2 above the down hammer 1. When reaching the bedrock, the bedrock is drilled and cut in small diameter by vertically moving the down hammer 1 while injecting fluid with high pressure from the head end of the down hammer 1. A part drill in small diameter by the down hammer 1 is drill in large diameter by the rotating drill bit for rock drilling 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for continuously drilling a soil layer and a rock mass.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Publication No. 7-91930 and Japanese Patent Publication No. 7-91931 are known as devices for drilling rock mass. This device is provided with a down hammer at the lower end of the rotary shaft that rocks up and down, and ejects fluid from the lower end of the down hammer.

In the above-mentioned device, the down hammer is operated while rotating the rotary shaft to excavate the earth and sand layer, and when it reaches the bedrock, the downhammer is used to rock the bedrock while ejecting fluid. ing. In the above conventional example, the diameter of the hole to be excavated is the same as that of the down hammer.

[0004]

However, in the above-mentioned conventional example, since the rotary shaft is rotated in the earth and sand layer and the down hammer is operated, the earth and sand layer is excavated. There is a problem that it takes time to excavate. In other words, the down hammer is suitable for vertically rocking the rock mass, but when excavating while driving the down hammer up and down in the sediment layer, the up and down movement of the down hammer tightens the soil, rather Will hinder the excavation. Moreover, in the conventional example, since the diameter of the down hammer is the same as the diameter of the hole to be excavated, it takes time to further excavate the sediment layer, and the diameter of the down hammer becomes larger. According to this, since the above-mentioned excavation of the sediment layer becomes slow, it is difficult to apply a down hammer having a large diameter to actual construction, and as a result, it is difficult to form a large diameter hole.

The present invention has been made in view of the above-mentioned problems of the conventional example, and can be quickly and continuously constructed from the earth and sand layer to the bedrock, and the earth and sand layer can be drilled with a large diameter. A main object is to provide a method for drilling a rock and a device therefor, and also a pillar body and a ground in which a soil and a soil penetrating to a part of the rock and a hardening liquid are mixed and hardened. Columns that can form walls and earth retaining walls and improve the ground, and can absorb the horizontal force such as an earthquake when it penetrates through the earth and sand layer and reaches a part of the bedrock, Another object of the present invention is to provide a method and a device for boring a soil layer and a rock bed, which can form an underground wall and a retaining wall and improve the ground.

[0006]

A method for drilling a layer of earth and sand according to the present invention has a function of injecting a high pressure fluid downward from a tip and a down hammer for drilling a rock 4 by vertical movement. When excavating the earth and sand layer 3 and the bedrock 4 following the earth and sand layer 3 with a device having a rock excavation rotary excavation bit 2 which is larger in diameter than the down hammer 1 and which is drilled by rotation, When excavating the layer 3, the lower part of the down hammer 1 is pierced and excavated while ejecting a high pressure fluid from the tip of the down hammer 1, and the earth and sand layer 3 is excavated by rotating the rock excavation rotary excavation bit 2 above the down hammer 1. When reaching the bedrock 4, the downhammer 1 is moved up and down while ejecting a high pressure fluid from the tip of the downhammer 1 to cut the bedrock 4 into a small diameter,
The rock drilling rotary drilling bit 2 for rotating a portion drilled to a small diameter by the down hammer 1 is drilled to a large diameter. By doing this,
When excavating the earth and sand layer 3, by loosening the earth and sand layer 3 below the dow hammer 1 with a fluid that is injected at high pressure,
Since the down hammer 1 can be inserted without resistance, and the diameter of the down hammer 1 is smaller than the hole diameter to be formed, the down hammer 1 can be further inserted into the earth and sand layer 3 without resistance, and the rotary drilling bit 2 for rock drilling is large. Although the diameter is small, the earth and sand layer 3 loosened by the fluid injected at high pressure is rotated while rotating. Then, when reaching the bedrock 4, the down hammer 1 is vertically driven while jetting a fluid to drill the bedrock 4, and after this downhammer 1 is drilled to a small diameter, the periphery is rotated for rock drilling of a large diameter. The drill bit 2 is rotated to drill a large-diameter hole.

Further, when boring the earth and sand layer 3, a liquid is ejected as a fluid to stir and mix the liquid and the excavated earth and sand when boring the earth and sand layer 3, and a down hammer as a fluid when boring the bedrock 4. It is also preferable to inject the high-pressure gas used to drive 1 up and down. By doing so, it is possible to form a column body in which excavated soil and liquid are mixed by stirring. When drilling the rock bed 4, the high-pressure gas used to drive the down hammer 1 up and down is used to blow the debris that has been rock drilled before drilling the rock bed 4 to remove the down hammer 1. The digging of can be facilitated. Further, in this case, if the liquid is simultaneously jetted together with the gas, the liquid can cool the down hammer 1 and the rock drilling rotary excavation bit 2 to prevent wear due to frictional heat.

Further, it is preferable that the liquid is a congealing liquid such as cement milk. In this structure, the soil pillars 5 extending from the sediment layer 3 to the bedrock 4 can be formed. Further, it is also preferable to mix a solution that exhibits elasticity after curing into the consolidation liquid. In this structure, the soil pillar 5 extending from the earth and sand layer 3 to the bedrock 4 has elasticity and can absorb horizontal external force such as an earthquake.

Further, a plurality of soil pillars 5 that mix the earth and sand and the congealing liquid and reach the bottom end of the bedrock 4 at the same time, or mix the earth and sand and the congealing liquid and form the bottom end The soil pillars 5 that extend into the bedrock 4 are formed so as to be continuous in the lateral direction with some overlap, or the soil layer 3
It is also preferable to improve the ground over the ground and the rock 4. By doing so, it is possible to form pillars, soil walls, earth retaining walls and ground improvement in which the soil and the soil from the soil layer 3 to the rock are mixed and hardened.

The device for boring the earth and sand layer 3 and the bedrock 4 according to the present invention has a function of injecting a fluid at a high pressure downward from the tip and has a down hammer 1 for boring the bedrock 4 by moving up and down. A rock excavating rotary drilling bit 2 having a diameter larger than the down hammer 1 and drilled by rotation
Is provided. With such a configuration, it is possible to provide a device that can easily perform the drilling from the sediment layer 3 to the bedrock 4.

Further, when the down hammer 1 is provided at the lower end of the rotary shaft 6, a rock excavating rotary excavating bit 2 having a diameter larger than that of the down hammer 1 is provided above the down hammer 1.
It is also preferable to provide a stirring means 7 having a diameter equal to or smaller than that of the rock drilling rotary drilling bit 2 on the rotary shaft above the rock drilling rotary drilling bit 2. With such a configuration, it is possible to provide a device for forming the soil column 5 in which the liquid and the consolidating liquid are agitated and mixed in the hole drilled from the earth and sand layer 3 to the bedrock 4 described above.

Further, when the fluid is jetted at a high pressure downward from the tip, it is also preferable to provide a plurality of jet holes 8 having different jet angles. With such a configuration, when excavating the earth and sand layer 3, when loosening the earth and sand layer 3 in advance with a fluid, the earth and sand in the lower region of the rock drilling rotary drilling bit 2 as well as the down hammer 1 are loosened. The layer 3 can be loosened, and the down hammer 1 and the rock drilling rotary excavating bit 2 can smoothly excavate the sediment layer 3. Further, in the rock bed 4 portion, when drilling with the down hammer 1 and the rock drilling rotary excavation bit 2, the drilled cuttings can be blown away to facilitate the down hammer 1 to advance.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the accompanying drawings. Rail 1 of crawler crane 10
1, an elevating body 12 is suspended vertically so that a rotating shaft 6 is rotatably attached to a lower portion of the elevating body 12, and the rotating shaft 6 is rotated by a motor provided in the elevating body 12. It is like this.

A down hammer 1 is attached to the lower end of the rotary shaft 6, and a rock drilling bit for rock drilling, which has a diameter larger than that of the down hammer 1 and is drilled by rotation, is attached to the upper portion of the down hammer 1. 2 is provided. Further, stirring means 7 such as a stirring blade 7a and a screw portion 7b is provided above the rotary shaft 6 above the rock drilling rotary excavating bit 2. As the stirring means 7, a screw portion 7b may be provided partially or substantially over the entire length in the vertical direction of the rotary shaft 6 as shown in FIGS. 2, 3 and 15, or a screw portion 7b and the screw portion 7b may be stirred as shown in FIG. The blade portion 7a is provided, or although not shown, only the stirring blade 7a is provided, and either one may be adopted.

The rotating shaft 6 is composed of a pipe having a hollow inside, and a fluid supply pipe is internally provided in a hollow portion inside, and the fluid supply pipe includes a gas supply pipe 13 and a liquid supply pipe 1.
It is composed of 4 and. An excavation unit 15 is attached to the lower end of the rotary shaft 6, and in the embodiment of FIG. 1, the excavation unit 15 is provided with a down hammer 1 and a rock excavation rotary excavation bit 2.

That is, in the embodiment shown in FIG. 1, the down hammer 1 is installed in the lower portion of the tubular body 16 which forms the outer shell of the drilling unit 15, and the rock drilling for rock drilling is provided in the central portion or the upper outer peripheral portion of the tubular body 16. Bit 2 is provided. The tubular body 16 is a cylinder of the down hammer 1, and the upper portion of the down hammer 1 is internally movably installed in the lower portion of the tubular body 16. The lower part of the down hammer 1, which can move up and down, is the cylinder 1.
6 is projected downward, and the diameter thereof is 16
The size of the chisel rock bit 17 is about the same as the diameter. Reference numeral 18 in the drawing denotes a spring for urging the down hammer 1 upward. A piston 19 for hitting the down hammer 1 is vertically movably installed inside a cylinder body 16 which is a cylinder. A gas switching valve 20 is housed in the upper part of the cylindrical body 16 so as to be freely movable in a seesaw motion. An annular gas passage 21 communicates with the gas supply pipe 13 and communicates with the gas switching valve 20. A first gas pressure inlet 22 communicating with the inside of the upper portion of the tubular body 16 is bored at a position corresponding to one end of the gas switching valve 20.
A second gas pressure inlet 23 is bored at a position corresponding to the other end side of the cylinder 16, and a gas flow path 25 communicating with the lower chamber of the sliding portion 24 of the piston 19 is bored in the wall of the cylindrical body 16. Therefore, the gas flow path 25 and the second gas pressure inlet 23 communicate with each other. Here, 26 in the figure is the leg portion 2 of the piston 19.
An air exhaust portion that communicates the chamber below 7 with the outside, and an exhaust port 28 for exhausting gas above and below the piston 19. A gas exhaust path 29 having an exhaust port 28 at its upper end is bored in the wall of the cylindrical body 16, and the gas exhaust path 2 is provided.
The lower end of 9 is a hole 30 that opens to the inner peripheral surface of the lower end of the tubular body 16. On the other hand, the down hammer 1 is provided with a gas discharge passage 31, and an upper portion of the gas discharge passage 31 is a hole portion 32 opened to the side surface of the down hammer 1, and the above hole portion 30 and the hole portion 32 are It is in communication. Here, at least one of the hole 30 and the hole 32 is a long hole that is long in the vertical direction, and the communication relationship between the hole 30 and the hole 32 is maintained even if the down hammer 1 moves up and down. Is set to. The lower portion of the gas discharge passage 31 provided in the down hammer 1 is branched into a plurality of gas injection holes 8a.

A liquid supply passage 33, which is connected to the liquid supply pipe 14 in a state where the excavation unit 15 is connected to the lower end of the rotary shaft 6, is provided in the wall of the cylindrical body 16. The lower end is a hole 34 that opens to the inner peripheral surface of the lower end of the tubular body 16. On the other hand, the down hammer 1 is provided with a liquid passage 36, and an upper portion of the liquid passage 36 is a hole portion 35 opened on a side surface of the down hammer 1. The above-mentioned hole portions 34 and 35 are shown in FIG. As shown in. Here, at least one of the hole portion 34 and the hole portion 35 is a long hole that is long in the up-down direction, and the communication relationship between the hole portion 34 and the hole portion 35 is maintained even if the down hammer 1 moves up and down. Is set to. The lower part of the liquid passage 36 provided in the down hammer 1 is branched into a plurality of parts to form a liquid injection hole 8b.

Here, the liquid is jetted downward from the plurality of liquid jet holes 8b. When jetting downward, the angle formed by the jet direction with respect to the vertical line, that is, the jet angle. Are different from each other. here,
One is a downward injection that is nearly vertical, the other is a downward injection that is directed obliquely downward, or both are downward injection that is directed obliquely downward, but the angle that they make with respect to the vertical line is changed. Is. In any case, by injecting the liquid downward with a high pressure, the lower ground is set below the down hammer 1 so that the lower ground can be loosened by the liquid with the high pressure injection. As described above, due to the different angles formed by the vertical lines of the plurality of injection directions, the ground below the down hammer 1 and, of course, the rock drilling bit 2 for rock drilling having a larger diameter than the down hammer 1 It is designed to be ejected ahead of the ground.

Further, the jetting directions of the gas jetted from the plurality of gas jet holes 8a are also set to different angles with respect to the vertical line, that is, the jetting angles. here,
The operation of raising and lowering the down hammer 1 will be described below with reference to FIGS. 5 to 8. First, a gas such as pressurized air is supplied from the gas supply pipe 13 to the annular gas passage 21. At this time, the gas switching valve 20 is inclined so that the right side of the gas switching valve 20 faces downward, the first gas pressure inlet 22 is closed, and the gas flows from the second gas pressure inlet 23 through the gas flow path 25. The gas pushes the piston 19 upward. Further, when the piston 19 reaches the position just before the top dead center, the pressure above the piston 19 becomes equal to or higher than the supply pressure, and the gas switching valve 20 reverses so that the left side of the gas switching valve 20 becomes downward. Therefore, from the first gas pressure inlet 22 to FIG.
5, gas is pressed into the upper portion of the piston 19, and as shown by the arrow b in FIG. 5, the piston 19 descends while the gas below the piston 19 is discharged from the air exhaust portion 26, and further shown in FIG. As described above, the piston 19 descends and the leg portion 27 of the piston 19 strikes the down hammer 1 to cut the rock to be cut.

With the piston 19 lowered, the gas above the piston 19 is discharged from the exhaust port 28 as shown by the arrow c in FIG. 6, while the gas below the sliding portion 24 of the piston 19 is shown in FIG. As shown by the arrow d, the gas is supplied to the second gas pressure inlet 23 via the gas flow path 25 and the gas switching valve 20 is supplied.
And the second gas pressure inlet 23 is opened. As a result, as shown by the arrow e in FIG. 7, gas is pressed from the second gas pressure inlet 23 through the gas flow path 25 to the lower portion of the sliding portion 24 of the piston 19, and the reaction force hitting the down hammer 1 and the above The gas pushes up the piston 19, and when the piston 19 comes to the upper portion as shown in FIG. 8F, the pressure above the piston 19 rises and the gas switching valve 20 reverses as described above.

In this way, the piston 19 strikes the down hammer 1 while repeatedly moving up and down in the order of FIG. 5, FIG. 6, FIG. 7 and FIG. 8, so that it is covered by the chisel rock bit portion 17 below the down hammer 1. It is possible to cut rocks. The rock drilling rotary drilling bit 2 is provided above the down hammer 1 as described above. The rock drilling rotary drilling bit 2 has a diameter larger than the diameter of the chisel rock bit portion 17 below the down hammer 1. Has become. In the lower part of the rock excavation rotary drilling bit 2, not only the earth and sand layer 3 can be excavated by rotation, but also a blade portion 35 formed of a strong blade material capable of cutting rock by rotation is provided. The blade portion 35 is arranged so that it is located higher toward the outer side. That is, since the inner blade portion 35a is located at the bottom and the outer blade portion 35b is located at the top, the inner blade portion 35a is first excavated with a small diameter before excavation, and then the outer blade portion 35a. Excavation with a large diameter can be performed at the portion 35b.

In order to mount the upper end of the tubular body 16 of the excavating unit 15 on the lower end of the rotary shaft 6, a fitting projection 36 having a polygonal cross section is provided on the lower end of the rotary shaft 6, and the upper part of the tubular body 16 is mounted. A fitting recess 37 having a polygonal cross section is provided on the fitting projection 3
6 is fitted in the fitting recess 37, the pin 60 is inserted from the pin hole 38, and the pin 60 is locked in the locking recess 39 for attachment.

The diameter of the stirring means 7 provided on the rotary shaft 6 is equal to or smaller than the diameter of the rock drilling bit 2 for rock drilling, that is, the diameter of the stirring means 7 is the same as or smaller than the diameter of the rotary drilling bit 2 for rock drilling. Has become. Next, a method for continuously drilling from the earth and sand layer 3 to the bedrock 4 using the apparatus having the above-described configuration will be described.

First, when excavating the earth and sand layer 3, the rotary shaft 6
Is rotated and the apparatus is moved downward while injecting a consolidating liquid such as cement milk downward from a plurality of liquid ejecting holes 8b provided in the chisel rock bit portion 17 of the down hammer 1 while high pressure is ejected downward. Here, when excavating the earth and sand layer 3, the down hammer 1 does not operate. This is a down hammer 1
Is operated and moved up and down, the earth and sand layer 3 below the down hammer 1 is in a state of being compacted, which hinders excavation, and therefore the down hammer 1 does not operate. Then, by rotating the rotary shaft 6 and injecting a consolidating liquid such as cement milk downward from a plurality of liquid injection holes 8b provided in the chisel rock bit portion 17 of the lower hammer 1, Since the earth and sand layer 3 below the down hammer 1 is excavated while being loosened prior to the down hammer 1, the down hammer 1 portion can move down smoothly. Here, since the down hammer 1 is smaller than the hole diameter to be formed (that is, the hole diameter to be formed is the diameter of the rock drilling rotary excavation bit 2), the earth and sand loosened by the high-pressure injection of the consolidation liquid are excavated. It will be possible to move down into layer 3 more smoothly. At the upper position of the down hammer 1, the rock excavating rotary excavating bit 2 having a larger diameter than the down hammer 1 rotates, so that the earth and sand layer 3 loosened and excavated by the high-pressure injection of the consolidation liquid. As a result, even if the down hammer 1 is provided, the earth and sand layer 3 can be excavated to a large diameter at a high excavation speed. During this time,
The stirrer 7 stirs and mixes the consolidation liquid and the excavated earth and sand.

When the down hammer 1 at the tip reaches the bedrock 4 by excavating the earth and sand layer 3 in this way, high-pressure gas is supplied to the gas supply pipe 13 while continuing rotation of the rotary shaft 6, Operate the hammer 1. By supplying high-pressure gas and operating the down hammer 1 to move up and down as described above, a small-diameter hole is drilled while hitting the bedrock 4 by the chisel rock bit portion 17 under the down hammer 1. . In this way, the rock mass 4 is drilled to a small diameter by the down hammer 1 and the rock mass around the small diameter drill hole is cracked, and subsequently, the rock drilling located on the upper part of the down hammer 1 is performed. The rock excavation bit 2 for use drills the rock bed 4 to a large diameter. Here, as described above, the small-diameter down hammer 1 precedes the formation of a small-diameter drilling hole in the bedrock 4, and cracks occur around the small-diameter drilling hole. Even the drill bit 2 can be easily drilled to form a desired large-diameter hole. In addition, in this case, since the blade portion 35 of the rock drilling rotary drilling bit 2 is arranged so as to be positioned higher toward the outer side, the periphery of the small diameter drilled hole previously drilled by the down hammer 1 is surrounded. First, the inner blade portion 35a located below is rock drilled by rotation, and then the outer peripheral portion thereof is rock drilled by the outer blade portion 35b. It can be formed on the bedrock 4. During the rock cutting as described above, the high-pressure gas used to operate the down hammer 1 is injected from the plurality of gas injection holes 8a, blows off the shavings cut by the down hammer 1, and the down hammer 1 and the rock. This facilitates drilling with the rotary drilling bit 2 for shaving.

A congealing solution may be sprayed during the rock cutting of the bedrock 4. In this case, the solidifying solution is simultaneously injected with high pressure into the rock cutting of the bedrock 4 together with the gas. When the consolidating liquid is sprayed, the chisel rock part 17 and the rock drilling excavation bit 2 under the down hammer 1 are cooled while the rock mass 4 is being rocked, and the down hammer 1 and the rock drilling excavation bit 2 are cooled. Cooling can prevent wear due to frictional heat.

After drilling the rock bed 4 to a predetermined depth as described above, the rotary shaft 1 is pulled up. When the rotary shaft 6 is pulled up, it is preferable to pull the rotary shaft 6 forward or backward while stirring and mixing the consolidating liquid and the excavated soil, but it is also possible to stop the rotation and pull up. At the time of pulling up, the consolidating liquid may or may not be sprayed. Also,
At the time of pulling up, gas may or may not be injected, but when gas is injected, the stirring effect is improved.

In this way, the hardened soil (that is, the soil pillar 5) obtained by stirring and mixing the solidifying liquid and the excavated earth and sand is formed so as to extend from the earth and sand layer 3 to a predetermined depth of the bedrock 4. By continuing the soil pillars 5 formed as described above, it is possible to form an earth retaining wall or an underground wall whose lower portion reaches the bedrock 4. In addition, the soil pillars 5 are formed continuously or at a distance so that the lower part of the bedrock 4 is formed.
The ground can be improved to reach the inside.

By the way, the rotary shaft 6 may be a single shaft, but may be a multi-shaft as shown in FIG. Here, in the case of multi-axis,
As shown in FIG. 3, the adjacent excavation units 15 are arranged vertically offset from each other. In FIG. 3, the rotation trajectories of the rock excavation rotary excavation bits 2 of the adjacent excavation units 15 partially overlap each other in plan view. Therefore, when the present device is used, a plurality of rotation trajectories are generated as shown in FIG. The soil column row 40 in which the soil columns 5 partially overlap can be formed by one excavation.
The soil column row 40 thus formed can further form a continuous wall by further overlapping the ends. Further, the rotation loci of the rock excavation rotary excavation bits 2 of the adjacent excavation units 15 may be in contact with each other in a plan view. By using this apparatus, the soil column row 40 in contact with the soil column 5 can be formed by one excavation as shown in FIG. The continuous wall can be formed by continuously forming the soil column array 40 thus formed. The wall may not only be formed as an underground wall or an earth retaining wall, but the ground may be improved as described above.

In the above-described embodiment, an example in which a consolidating liquid such as cement milk is used as the liquid to be sprayed has been described. However, a solution exhibiting elasticity after curing is mixed in this consolidating liquid. May be. As the solution exhibiting elasticity after curing, a synthetic resin liquid such as polyurethane resin exhibiting elasticity after curing is used. Of course, the present invention is not limited to this exemplified product, and any other solution may be used as long as it has elasticity after curing. When a solution exhibiting elasticity after curing is mixed in the consolidation liquid in this manner, the soil pillars 5 (or the ones in which these are continuous) to be formed have elasticity by themselves, and earthquakes, etc. It is possible to prevent the occurrence of cracks, to prevent the deterioration of strength, and to prevent the deterioration of water blocking property.

By the way, in the embodiment shown in FIG. 1, a fitting projection 36 at the lower end of the rotary shaft 6 is provided, and a fitting recess 37 at the upper part of the cylinder 16 is fitted and engaged by a pin. Therefore, remove the drilling unit 15 by removing the pin,
FIG. 1 shows a bit 50 exclusively used for a general publicly known earth and sand layer 3.
It can be attached as shown in FIG. 6 and used as a general drilling device.

17 to 19 show another embodiment of the present invention. In the present embodiment, the upper end portion of the second excavation unit 15b having the large-diameter rotary rock excavation bit 2 of the present invention is detachably attached to the lower end portion of the rotary shaft 6, and the second excavation unit is further installed. The upper end of the first excavation unit 15a equipped with the down hammer 1 may be detachably attached to the lower end of 15b.
Here, each component can be attached by the same structure as the above-described attachment structure of the rotary shaft 6 and the excavation unit 15. In addition, also in this embodiment, the mechanism of the down hammer 1 can employ the same mechanism as the above-mentioned embodiment.

[0033]

As described above, according to the first aspect of the present invention, as described above, the down hammer having the function of injecting the fluid at a high pressure downward from the tip end and drilling the rock mass by the vertical movement is used. When excavating the earth and sand layer and the bedrock below the earth and sand layer with a device that has a rotary excavation bit for rock drilling that has a diameter larger than the down hammer and is drilled by rotation, the down hammer is used to excavate the earth and sand layer. High-pressure fluid is ejected from the tip of the down hammer while drilling the bottom of the down hammer while ejecting fluid from the tip of the down hammer, and excavating the earth and sand layer by rotating the rock drilling rotary drilling bit above the down hammer. While ejecting, the down hammer is moved up and down to excavate the bedrock into a small diameter, and this down hammer rotates the portion excavated into a small diameter. Since a large diameter hole is drilled by a rock drilling bit for rock drilling, despite the down hammer being provided at the lower end, when excavating the sediment layer, the sediment layer below the small diameter down hammer is preceded by high pressure fluid. By loosening and excavating, the down hammer can move down smoothly, especially because the down hammer has a small diameter, it can move down more smoothly, and moreover, it rotates in the upper position of the down hammer. The rock excavation rotary drilling bit enables simple and reliable drilling of a large layer of sand and sand. As a result, even if a down hammer is provided, excavation of the layer of sand can be completed in a short time. It can be performed smoothly and accurately with a small diameter while drilling the bedrock with a down hammer while drilling the bedrock. The periphery of a hole is cracked, and subsequently, the periphery of a small diameter drilled hole that has been cracked can be drilled to the target diameter with a large diameter rotary drilling bit for rock drilling, and large diameter drilling is also possible. In addition, by injecting a high-pressure fluid into the rock drilling hole, it blows away the debris generated by the rock drilling, facilitating the drilling of the rock mass with a down hammer or a rotary drilling bit for rock drilling. It is a thing.

In addition to the effect of the invention according to claim 1, in addition to the effect of the invention according to claim 1, a liquid is ejected as a fluid when the earth and sand layer is drilled, and the liquid is ejected when the earth and sand layer is drilled. And the excavated earth and sand are agitated and mixed, and when the rock is drilled, the high pressure gas used to drive the down hammer up and down is injected as a fluid, so a soil column in which the liquid and the earth and sand layer are agitated and mixed can be formed. At the same time, when drilling the rock mass, the high-pressure gas used to drive the down hammer can be effectively used as it is for injection.

Further, in the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, since the liquid is a congealing liquid such as cement milk, as a soil cured body It is possible to form a hardened soil cement. In addition, in the invention described in claim 4, in addition to the effect of the invention described in claim 3, a soil formed by mixing a solution exhibiting elasticity after curing into the consolidation liquid. Since the cured body has elasticity, the soil cured body itself can absorb an external force such as an earthquake.

Further, in the invention of claim 5, in addition to the effect of the invention of any one of claims 1 to 4, the bottom end portion is obtained by mixing earth and sand with a congealing liquid. Since a plurality of soil pillars that reach inside the bedrock are simultaneously formed, it is possible to simultaneously form a row of soil pillars that reach the inside of the bedrock. In addition, in the invention of claim 6, in addition to the effect of the invention of any one of claims 1 to 4, a mixture of earth and sand and a congealing liquid and a lower end portion in the bedrock It is possible to easily form a row of soil columns where the bottom of the soil pillars partially overlap with each other in the lateral direction by forming the soil pillars that continue to partially overlap in the lateral direction. is there.

Further, in the invention of claim 7, in addition to the effect of the invention of any one of claims 1 to 6, since the ground is improved over the earth and sand layer and the rock, the lower part is The ground can be easily improved to reach the inside of the bedrock. Further, in the invention according to claim 8, it has a function of injecting a high pressure fluid downward from the tip and has a diameter larger than that of the down hammer for drilling rock mass by vertical movement and above the down hammer. Since the rotary drilling bit for rock drilling which is drilled by rotation is provided, it is possible to provide a device capable of drilling from the sediment layer to the inside of the bedrock with a simple configuration.

According to the invention of claim 9, in addition to the effect of the invention of claim 8, a down hammer is provided above the down hammer together with the down hammer provided at the lower end of the rotary shaft. A rock drilling bit for rock drilling with a diameter larger than that of the rock drilling bit is installed above the rock drilling bit for rock drilling on the rotating shaft. When drilling, the excavated soil and the liquid can be stirred and mixed at the same time when excavating.

In the invention according to claim 10,
In addition to the effect of the invention according to claim 8 or 9, in injecting a fluid at a high pressure downward from the tip, a plurality of injection holes having different injection angles are provided, so that when the earth and sand layer is dug, the fluid is used as a precursor. When loosening the sediment layer, the sediment layer not only under the down hammer but also under the rock excavation rotary drill bit can be loosened, and the down hammer and the rotary excavation bit for rock drilling smoothly excavate the sediment layer. In addition, in the bedrock part, when drilling with a down hammer and a rock drilling rotary drilling bit, it is possible to facilitate the advancement of the down hammer by blowing away the debris that has been rock drilled in advance. Is.

[Brief description of the drawings]

FIG. 1 is an exploded sectional view of an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a partially cutaway front view of the above.

FIG. 4 is a schematic bottom view showing a positional relationship between an inner blade portion and an outer blade portion of the rock drilling rotary drilling bit.

FIG. 5 is an explanatory diagram showing an operation sequence of the down hammer of the above.

FIG. 6 is an explanatory diagram showing an operation sequence of the down hammer of the above.

FIG. 7 is an explanatory diagram showing an operation sequence of the down hammer of the above.

FIG. 8 is an explanatory diagram showing an operation sequence of the down hammer of the above.

FIG. 9 is an explanatory diagram showing a communicating portion between the hole portion at the end of the liquid supply passage and the hole portion at the end of the liquid passage in the above.

FIG. 10 is an explanatory diagram showing a state in which the same sand layer is being excavated.

FIG. 11 is an explanatory diagram showing a state in which the above rock mass is being excavated.

FIG. 12 is a horizontal cross-sectional view of an example of a hardened soil body formed by the method of the present invention.

FIG. 13 is a horizontal cross-sectional view of another example of the above-mentioned soil cured body.

FIG. 14 is a front view of another embodiment of the device of the present invention.

FIG. 15 is a front view of yet another embodiment of the apparatus of the present invention.

FIG. 16 is a front view showing an example in which the excavation unit of the present invention is removed from the rotary shaft and a conventionally known bit for exclusive use of a general earth and sand layer is attached.

FIG. 17 is a front view of yet another embodiment of the apparatus of the present invention.

FIG. 18 is a front view of yet another embodiment of the device of the present invention.

FIG. 19 is a front view of yet another embodiment of the apparatus of the present invention.

[Explanation of symbols]

 1 Down hammer 2 Rotation drilling bit for rock drilling 3 Sediment layer 4 Rock bed 5 Soil column 6 Rotating shaft 7 Stirrer 8 Injection hole

Claims (10)

[Claims] 1. A rock drilling machine having a function of injecting a high pressure fluid downward from a tip and having a diameter larger than the down hammer and being drilled by rotation at the upper part of a down hammer for drilling rock mass by vertical movement. When excavating the sediment layer and the bedrock under the sediment layer with a device equipped with a rotary excavation bit, when excavating the sediment layer, high pressure fluid is ejected from the tip of the down hammer and the lower part of the down hammer is perforated and down excavated. The earth and sand layer is excavated by the rotation of the rock excavation rotary drilling bit above the hammer, and when the rock is reached, the down hammer is vertically moved while jetting fluid from the tip of the down hammer, and the rock is cut into a small diameter. Features a large diameter drilling hole using a rotary drilling bit for rock drilling, which rotates a portion that has been drilled into a small diameter by a down hammer A method of drilling the earth and sand layers and rock. 2. When drilling a sediment layer, a liquid is ejected as a fluid to stir and mix the liquid and the excavated sediment when drilling the sediment layer, and when drilling a rock, a down hammer is vertically driven as a fluid. The method for boring a soil layer and a bedrock according to claim 1, characterized in that a high-pressure gas used to do so is injected. 3. The method for boring a soil layer and rock mass according to claim 1 or 2, wherein the liquid is a hardening liquid such as cement milk. 4. The method for boring a soil layer and rock mass according to claim 3, wherein a solution exhibiting elasticity after being hardened is mixed in the consolidation liquid. 5. The method according to claim 1, wherein a plurality of soil columns are mixed at the same time by mixing the excavated soil and the congealing liquid and the lower ends of the soil columns reach the bedrock. A method for drilling a layer of earth and sand. 6. The method according to claim 1, wherein the excavation and the congealing liquid are mixed, and the soil columns whose lower ends reach the inside of the bedrock are formed so as to be continuous in a state of partially overlapping in the lateral direction. A method for boring the earth and sand layer and the rock mass according to claim 4. 7. The method for boring a soil layer and a rock layer according to claim 1, wherein the soil layer is improved over the soil layer and the rock layer. 8. A rock drilling machine having a function of injecting a high pressure fluid downward from a tip and having a diameter larger than the down hammer and being drilled by rotation at the upper part of a down hammer for boring rock by vertical movement. A device for boring a soil layer and rock mass, which is provided with a rotary drilling bit. 9. A rock drilling bit for rock drilling having a diameter larger than that of the down hammer is provided above the down hammer when the down hammer is provided at the lower end of the rotary shaft, and a rotary drilling bit for rock drilling of the rotary shaft is provided. 9. An apparatus for boring a soil layer and a rock bed according to claim 8, further comprising a stirring means having a diameter equal to or smaller than that of a rotary excavating bit for rock drilling provided at an upper position. 10. The earth and sand layers according to claim 8 or 9, wherein a plurality of injection holes having different injection angles are provided when high-pressure jetting a fluid downward from the tip. A device to pierce.