JP5622759B2 - Ground improvement device - Google Patents

Description

  The present invention relates to a ground improvement device for forming a hole in soft ground and embedding crushed stones and piles therein.

  Patent Document 1 described later is an invention related to a ground improvement method. A hole is formed in the soft ground, and aggregates (crushed stones) dropped into the ground are solidified to construct a reinforcing layer (stone pillar) in the ground. Is disclosed. When forming the hole, a screw drill in which a spirally extending blade is joined to the side peripheral surface is used. The screw drill is cylindrical and pushes soft ground horizontally to form a hole. Therefore, only a small amount of earth and sand can be scooped up on the ground surface, and no soil removal treatment is required. Moreover, when the ground is pushed out in the horizontal direction, the water is squeezed out and the fluidity is lowered. Therefore, even after the screw drill is pulled out, the hole does not collapse immediately, and the crushed stone can be dropped without difficulty. The dropped crushed stone is solidified by a rolling pressure pipe and becomes a stone pillar.

  At present, when constructing large-scale buildings, foundation piles are often driven using a construction machine having a column called a leader mast. Depending on the geology, it is necessary to excavate the ground before driving the foundation pile, and in addition to a device for driving the foundation pile, a device for excavating the ground may be incorporated into a single leader mast. For this reason, a reader mast called a rotary reader or a double-sided reader has been developed. Specific examples include Patent Document 2 and Patent Document 3 described later.

  Patent Document 2 discloses a “leader rotating device in a rotary two-sided leader pile driver”. The pile driver in this document has a structure in which one leader mast is suspended by a boom extending from a truck. One side of the leader mast is equipped with an auger screw, and the other side is equipped with monken. doing. Furthermore, the leader mast has a structure that can rotate with respect to the base body positioned thereon. Therefore, after excavating a hole with an auger screw and rotating the leader mast without moving the truck, pile driving with monken can be started.

  Patent Document 3 discloses a “double-sided reader device”. In the apparatus of this document, two work machines (a first work machine and a second work machine) are arranged to face a single reader mast. The two working machines have a structure that can be lifted and lowered by only one lift cylinder, and the apparatus is simplified, so that the cost can be reduced. However, in the present invention, the lift cylinder and the two work machines are connected by a chain, and it is not possible to raise and lower only the individual work machines.

Japanese Patent No. 4566634 Japanese Utility Model Publication No. 55-136840 JP-A-11-336458

  The invention of Patent Document 1 described above is an excellent technique that reinforces the ground by compacting crushed stones and has very little environmental impact. However, in order to obtain a sufficient supporting force, it is necessary to repeat a series of steps at intervals of about 2 meters, which may hinder the spread of this technology in terms of time and cost. Hole formation and crushed stone can also be done with general-purpose construction machines, but in that case, the operation method such as screw drill is complicated, and a compaction pipe that rams crushed stone is placed right above the hole. It is necessary, and experience and skill are required for the work, and there is a risk that the spread will be hindered in this respect as well.

  The techniques disclosed in Patent Document 2 and Patent Document 3 realize two functions with a single reader mast. Among them, Patent Document 2 has a disadvantage in terms of maintenance and weight balance because a complicated structure is incorporated in a limited space above the leader mast in order to rotate the leader mast. Patent Document 3 can simplify the structure of the leader mast and is advantageous in terms of apparatus price and maintenance. However, when switching the work, it is necessary to move the entire leader mast, which is disadvantageous in position adjustment.

  The present invention was developed on the basis of such circumstances, and provides a ground improvement device that can smoothly perform a series of operations on a ground improvement method in which holes are formed in soft ground and crushed stones and piles are embedded therein. It is an object.

The invention of claim 1, wherein for solving the above problems is to form a hole in the ground with a screw drill, embedding crushed stone or pile bore, a soil modifying apparatus for pressing them rolling in applying member , A traveling means capable of freely moving on rough terrain, a body mounted on the traveling means, a leader mast capable of falling down , two sliders movable along the leader mast, and individually driving the sliders An elevating device, an auger that integrally rotates with one slider and rotates the screw drill, a clamper that integrates with the other slider and holds the rolling tool, a swivel wheel that can rotate the entire body, comprising a hopper for accommodating the crushed stone embedded in the hole, and a chute for feeding the crushed stone in the rolling applying member near the screw drill, collected a cylindrical body, the side peripheral surface of the barrel body spirally And the blade winding, a central shaft which is inserted into the auger projects from the rear end of the body, and an exhaust port for supplying air to the located in the vicinity of the tip within the bore, made from the rolling applying member, the crushed stone or the A pressing body that collides with the pile, and a support shaft that protrudes from the rear end of the pressing body and is held by the clamper, and the central axis and the support shaft are arranged at an equal distance from the rotation center of the swirling wheel The hopper has the same size as the width of the body, thereby eliminating the cockpit. As an alternative, the movable unit can be remotely operated with a portable controller. Or it is the ground improvement apparatus characterized by being able to implement the process to embedding a pile continuously and repeatedly .

  The present invention is an apparatus for realizing the ground improvement method disclosed in Patent Document 1 described above, and includes a screw drill that forms a hole in soft ground, and a rolling tool that squeezes crushed stone dropped into the hole. use. By piercing the ground while rotating the screw drill and extruding the earth and sand in the horizontal direction, moisture is squeezed out and the collapse of the formed hole can be suppressed. In addition, stone pillars that are tightly entangled with the ground are formed by crushing the crushed stone dropped into the hole with a rolling tool. Depending on the geology, instead of crushed stone, a pile made of thinned wood may be inserted and driven with a rolling tool.

  A screw drill is composed of a cylindrical fuselage, a blade that spirals around its side surface, and a central axis that protrudes from the center of the rear end face of the fuselage. give. The rolling tool is composed of a pressing body that crushes and crushes the crushed stone, and a support shaft that protrudes from the rear end surface of the pressing body. The pressing body preferably has a slightly smaller cross-sectional shape than the body of the screw drill, can smoothly enter the hole, and can contact the entire upper surface of the crushed stone.

  The ground improvement device according to the present invention is based on a construction machine such as a hydraulic excavator, and includes a plurality of elements such as traveling means and a leader mast. The traveling means is for causing the entire apparatus to self-travel along the ground surface, and includes an endless track, a power transmission mechanism, and the like. Since the present invention is used on rough ground with soft ground, it is necessary to reduce the contact pressure. Therefore, when using a tire as a traveling means, the number is increased as much as possible. Next, the body is a vehicle body mounted on the traveling means, and has a function as a base for installing various equipment in addition to accommodating an engine as a power source.

  The leader mast is a columnar shape that stands upright from the ground, is located in front of the device, is supported by an arm extending from the body, and suspends both the screw drill and the rolling tool. The arm may protrude directly from the body, but an angle adjustment mechanism or the like may be sandwiched between the body and the arm. The slider can be freely moved along the longitudinal direction of the leader mast, and is incorporated into the leader mast via a guide rail or the like. Next, the lifting device is for moving the slider, and can be freely selected from a method using a hydraulic cylinder, a method in which a chain or rack is attached to the side surface of the leader mast, and a sprocket or pinion is engaged therewith.

  Two sliders are required for one leader mast for the screw drill and the rolling tool, and the two sliders are arranged separately to prevent interference with the other. Also, two lifting devices are required so that each slider can move independently. An auger for rotating the screw drill is incorporated in the slider for the screw drill. By inserting the center axis of the screw drill into this auger, the screw drill can be moved up and down, and it can be rotated around the axis, and the blades of the screw drill bite into the ground, generating vertical thrust To do.

  The other slider incorporates a clamper for attaching the rolling tool. The clamper only needs to hold a support shaft protruding from the rear end of the rolling tool and move up and down. The screw drill and rolling tool can be detached from the auger and clamper, and removed from the device except during work.

The hopper is for accommodating the crushed stone dropped in the hole formed in the ground, and is provided on the upper part of the body. Note hopper, to enhance the efficiency of work, rather is preferably as much as possible in size, and the width equivalent to the size of the body. In addition, a conveyor and chute are provided to guide the crushed stone that has fallen from the hopper to the hole .

  The leader mast hangs a screw drill and so on, so it is at least 4 meters above the ground. When transported to the site, the leader mast may break through the height restrictions on public roads. Therefore, the leader mast has a structure that can rotate around the pin at the tip of the arm, and is lowered substantially horizontally during transportation to suppress the height.

  When using this device, after transporting to the site, the lying leader mast is upright and both sliders are moved to the top. Next, the central axis of the screw drill is inserted into the auger, similarly, the support shaft of the rolling tool is inserted into the clamper, and crushed stone is further packed into the hopper. Thereafter, the traveling means moves to a predetermined position, operates the auger and the lifting device, and gradually lowers the screw drill. When the blades of the screw drill enter the ground and a downward driving force is generated, the screw drill sinks into the ground independently.

  Then, when the screw drill reaches a specified depth, the lifting device is operated to pull out the screw drill from the ground. Next, the position of the device is corrected, and crushed stone is dropped from the hopper toward the hole. After that, when the rolling tool is lowered to crush the crushed stone, a stone pillar body in which the crushed stones are densely built is constructed. By continuously constructing this stone pillar body at a predetermined interval, the ground within a certain range is improved and various buildings can be supported.

  Soft ground has high fluidity, and earth and sand will adhere to the embedded screw drill. Therefore, when pulling out the screw drill from the ground, negative pressure is generated near the lower end of the screw drill, and the hole may collapse. In order to prevent this, an exhaust port for supplying air to the outside is provided at the tip of the screw drill. Furthermore, at locations where there is springing out of groundwater, when forming holes with a screw drill, forced air is forced into the ground from the exhaust port to push the groundwater away and suppress collapse of the holes. For the rolling tool, compressed air may be injected while an exhaust port is provided for the same reason and inserted into the hole.

In addition, the apparatus which concerns on this invention cannot arrange | position a screw drill and a rolling tool coaxially on the structure . Therefore, after forming a hole with a screw drill, it is necessary to move the leader mast by some means when solidifying the crushed stone. In order to reduce the labor required for position adjustment at that time , a turning wheel is provided.

  The swivel wheel is a turntable-like device provided between the traveling means and the body, and the entire body can be freely rotated on a horizontal plane, and is widely introduced in hydraulic excavators and the like. Furthermore, the screw drill and the rolling tool are arranged equidistant from the center of the swivel wheel. Thus, when the formation of the hole is completed and the crushed stone is compacted, the rolling tool can be moved directly above the hole by merely operating the swivel wheel. The swivel wheel is easy to fine tune and can be positioned quickly and accurately. In an actual apparatus, holes (holes for inserting a central shaft and a support shaft) provided in each of the auger and the clamper are arranged at an equal distance from the center of the swirling wheel.

In addition, the device according to the present invention is characterized by including a portable controller for remotely operating each movable part such as an auger. Like a normal construction machine , when a driver's seat is provided on the body, the position of the screw drill or the rolling tool cannot be grasped, and the work efficiency may be reduced. Therefore, by enabling remote operation using a controller , ground improvement can be promoted by only one worker while monitoring a screw drill or the like from the vicinity of the leader mast. In addition, when the ground improvement was advanced by the conventional method, it was necessary to arrange a plurality of workers for operation and monitoring.

  The controller is preferably of a size that can be easily carried by a human hand, and is preferably capable of operating all the series of steps from the formation of a hole by a screw drill to the crushing of crushed stone. The controller transmits information to a control device mounted on the body by wire or wirelessly.

Invention of Claim 2 respond | corresponds to the case where not a crushed stone but the pile is embedded in the hole formed with the screw drill, The upper part of a leader mast is equipped with the lifting tool which lifts a pile, It is characterized by the above-mentioned. To do. When embedding a pile, it is necessary to lift the pile and carry it directly above the hole, and some kind of hanging tool is indispensable. Although a small mobile crane can be used separately as a lifting tool, an increase in labor is inevitable. On the other hand, if a lifting tool is provided on the upper part of the leader mast as in the present invention, it is very easy to lift the pile, and the work can be carried out smoothly. A specific example of the hanger is a simple hook. A short boom is provided at the top of the leader mast, and the hook is hung from the tip.

  As in the first aspect of the invention, the ground improvement device is constituted by a traveling means, a leader mast, a hopper, etc., two sliders are incorporated in one leader mast, a screw drill is attached to one slider, and the other By attaching a rolling tool to the slider, it is possible to continuously carry out from the formation of a hole by a screw drill to the dropping of crushed stone and the rolling pressure. Therefore, a series of operations can be completed in a short time with a smaller number of people than before, and the cost required for ground improvement can be suppressed.

  In addition, since this device supports the screw drill and the rolling tool with a single leader mast, the operation principle is simple and the operability is excellent, and it does not depend on the experience or skill of the worker. In addition, the operation can be automated in combination with an electronic device. In addition, by allowing the leader mast to fall down, it can be transported by a trailer or the like without disassembling the device, and the time and labor required before and after ground improvement can be reduced.

In addition, a turning wheel is provided between the traveling means and the body, and the screw drill and the rolling tool are arranged at an equal distance from the center of rotation of the turning wheel to form a hole, and then smash the crushed stone. By simply rotating the swivel wheel, the rolling tool can be moved directly above the hole. Therefore, the positioning of the rolling tool can be completed in a short time, which contributes to shortening the working time. Since the present invention diverts a technique widely used in various construction machines, the manufacturing cost of the apparatus can be suppressed, and a complicated structure like a conventional rotary reader is unnecessary.

In addition, by having a portable controller and realizing remote operation of the ground improvement device, it is possible to carry out a series of processes from the formation of holes by screw drill to the compaction of crushed stone with only one worker. In addition to controlling the cost of ground improvement, the driver's seat on the body is no longer required. Therefore, the hopper that accommodates the crushed stone can be enlarged, and a series of processes can be repeated without break. The worker stands near the leader mast and operates the ground improvement device while monitoring the position of the screw drill and the like.

According to the second aspect of the present invention, by providing a lifting tool at the upper part of the leader mast, when the pile is embedded in the ground, it is possible to lift the pile without difficulty and carry it directly above the hole. The lifting tool can also be used when attaching or detaching a screw drill or a rolling tool.

It is the front view and side view which show the example of a shape of the ground improvement apparatus by this invention. It is the top view of the ground improvement apparatus of FIG. 1, and has shown the step which forms a hole, and the step which solidifies crushed stone. It is a side view which shows the state which laid down the leader mast of the ground improvement apparatus of FIG. It is a front view which shows the state which inclined the leader mast of the ground improvement apparatus of FIG. 1 to the left side. It is a side view which shows the state which has formed the hole in the ground with the ground improvement apparatus of FIG. It is a side view which shows the state in which the hole was formed in the ground by the operation | work of FIG. It is a side view which shows the state in which the crushed stone is being dropped in the hole formed in the ground. It is a side view which shows the state in which the crushed stone is solidified and the stone pillar body is being constructed. It is a side view which shows the case where a pile is embedded in the hole formed in the ground. It is a side view which shows the state which formed the stone pillar body in the ground and built the building on it. It is the side view and sectional drawing which show the example of a shape of the screw drill used by this invention.

  FIG. 1 shows an example of the shape of a ground improvement device 10 according to the present invention, with the upper view seen from the front and the lower view seen from the side. A screw drill 41 that forms a hole H in the ground G includes a cylindrical body 43 that is tapered, a blade 44 that protrudes spirally from the side peripheral surface, and a central shaft 42 that protrudes from the rear end surface of the body 43. Consists of. The rolling tool 51 includes a cylindrical pressing body 53 in which the body 43 of the screw drill 41 is slightly narrowed, and a support shaft 52 protruding from the rear end surface. Both the screw drill 41 and the rolling tool 51 need to have their tips directed to the ground, and are suspended from the leader mast 29.

  The leader mast 29 is a column that rises vertically, and two sliders 31 and 36 are arranged on the left and right as viewed from the front. The sliders 31 and 36 can freely move up and down using the leader mast 29 as a guide, and do not leave the leader mast 29. In addition, two rows of vertically extending chains 34 are arranged on the side surface of the leader mast 29. Both ends of the chain 34 are fixed to the leader mast 29. The individual sliders 31 and 36 incorporate lifting devices 33 and 38 each composed of a motor and a sprocket, and the sprocket meshes with the chain 34 to realize vertical movement.

  The individual sliders 31 and 36 can be independently moved by dedicated lifting devices 33 and 38, and an auger 32 is incorporated in the left slider 31 as viewed from the front. The auger 32 has a function of holding and rotating the inserted shaft, and the central shaft 42 of the screw drill 41 is inserted in the present invention. On the other hand, a clamper 37 is incorporated in the slider 36 on the right side. The clamper 37 has only a function of holding the support shaft 52 of the rolling tool 51, and does not have a rotating function like the auger 32.

  The hopper 16 accommodates the crushed stone B dropped into the hole H formed by the screw drill 41, and includes a gate 17 at the bottom of the hopper 16. Further, in order to move the crushed stone B dropped from the hopper 16 directly below the rolling tool 51, a conveyor 18 is provided at the lower portion of the hopper 16, and further, the crushed stone B dropped from the conveyor 18 is guided to the hole H in an oblique direction. A chute 19 extending downward is provided. The tip of the chute 19 is adjacent to the rolling tool 51, and the dropping and tamping of the crushed stone B can be carried out without interruption, which contributes to shortening the working time.

  The ground improvement device 10 can freely move on rough terrain by the traveling means 12 using an endless track. A body 13 is placed on the traveling means 12 via the turning wheel 11. The swivel wheel 11 is for rotating the entire body 13 on a horizontal plane, and is used for adjusting the position of the leader mast 29. The body 13 is a base on which the leader mast 29, the hopper 16, and the like are placed. The body 13 houses an engine, a generator, a hydraulic pump, a compressor, and the like, and further includes an operation panel, a control device 14, and the like. Note that general-purpose products are used for the traveling means 12 using the endless track, the turning wheel 11, the body 13, and the like.

  The leader mast 29 is supported by a pin 27 driven in the vicinity of the tip of the arm 25 and has a structure that can swing around the pin 27. Further, an overturning cylinder 26 that is hydraulically operated is disposed on the arm 25, and the angle of the leader mast 29 can be freely adjusted by extending and contracting the cylinder. In addition, a lifting tool 39 is provided on the upper end of the leader mast 29 via a horizontally extending boom 35, and various materials can be lifted. The boom 35 can freely rotate on a horizontal plane.

  The arm 25 that supports the leader mast 29 does not protrude directly from the upper surface of the body 13 but protrudes from the upper surface of the table 21. The table 21 is a simple flat plate and is mounted on the body 13 via a hinge 22 and an adjustment cylinder 23, and the leader mast 29 can be tilted via the table 21 and the arm 25 by expanding and contracting the adjustment cylinder 23. it can. This mechanism is used to form the hole H vertically even when the body 13 is inclined in the lateral direction due to the inclination of the ground G or the uneven settlement of the traveling means 12, and the adjusting cylinder according to the inclination of the body 13. 23 is activated.

  The soft ground G has high fluidity and is easily in close contact with the embedded screw drill 41 and the rolling tool 51. Therefore, when pulling out the screw drill 41 and the rolling tool 51 from the ground G, negative pressure is generated in the vicinity of their lower ends, and the hole H may collapse. In order to prevent this situation, air is fed from the air hose 50 and sprayed to the outside from the tip of the screw drill 41 or the rolling tool 51. The air hose 50 is attached to the upper part of the screw drill 41 or the rolling tool 51 and can follow the movement of the sliders 31 and 36 and the leader mast 29. The upstream side of the air hose 50 is connected to a compressor housed in the body 13 although drawing is omitted.

  The timing of injecting air from the screw drill 41 or the rolling tool 51 differs depending on the ground G. For example, in a state where groundwater springs out, while the screw drill 41 or the rolling tool 51 enters the ground G, it always injects compressed air to push the groundwater away as far as possible, and the flow of sediment around the hole H Reduces sex and prolongs time to collapse. On the other hand, when the ground G is relatively stable, the upstream side of the air hose 50 is opened to the air without being connected to the compressor, and air is naturally released from the tip of the screw drill 41 or the rolling tool 51. Release.

  FIG. 2 is a top view of the ground improvement device 10 of FIG. The body 13 can be freely rotated by the turning wheel 11, and the centers of the screw drill 41 and the rolling tool 51 are arranged at an equal distance from the center of the turning wheel 11. Therefore, after the hole H is formed, the rolling tool 51 can be moved directly above the hole H by rotating the swivel wheel 11 by a predetermined angle.

  The upper part of FIG. 2 is a stage in which the hole H is formed by the screw drill 41. When the formation is completed, the swivel wheel 11 is rotated by a predetermined angle, and the compaction tool 51 is moved directly above the hole H as shown in the lower part of FIG. In addition, when shifting from formation of the hole H to tamping, the rotation angle of the turning wheel 11 is constant. Therefore, this angle can be stored in the control device 14 in advance and the body 13 can be automatically rotated.

  FIG. 3 shows a state in which the leader mast 29 of the ground improvement device 10 of FIG. When transporting the ground improvement device 10, after removing the screw drill 41 and the rolling tool 51, the fall cylinder 26 is contracted and the leader mast 29 is laid sideways to suppress the height. Considering that the leader mast 29 is laid down, the actual hopper 16 has a structure that can be partially disassembled.

  FIG. 4 shows the ground improvement device 10 of FIG. 1 as viewed from the front, and shows a state in which the leader mast 29 is tilted to the left. This device is supposed to be used on rough terrain, and the leader mast 29 is not always upright. Therefore, even when the body 13 is tilted due to unequal subsidence or the like, the table 21 or the like can be incorporated to cancel the tilt of the leader mast 29 so that normal work can be performed. An arm 25 that supports the leader mast 29 protrudes from the upper surface of the table 21. The table 21 is mounted on the body 13 via a hinge 22 and an adjustment cylinder 23. By changing the stroke of the adjustment cylinder 23, the table 21 can be tilted within a certain range. In the lower part of FIG. 4, the leader mast 29 is tilted to the left by extending the adjustment cylinder 23.

  FIG. 5 shows a state in which a hole H is formed in the ground G with the ground improvement device 10 of FIG. When the slider 31 to which the screw drill 41 is attached is positioned above, the screw drill 41 is rotated by the auger 32, and then the lifting device 33 is operated to gradually lower the slider 31. When the tip of the screw drill 41 comes into contact with the ground G, the lifting device 33 is set in an idling state so that the screw drill 41 can freely move up and down. Then, the tip of the blade 44 bites into the ground G, and the screw drill 41 descends autonomously by the propulsive force. Along with this, the surrounding earth and sand are pushed out by the body 43 in the horizontal direction, and moisture is squeezed out.

  When the screw drill 41 reaches a predetermined depth, the lifting device 33 is operated to pull out the screw drill 41. When the screw drill 41 is pulled out, compressed air is supplied from the air hose 50 and sprayed to the outside from the tip of the screw drill 41 to prevent the hole H from collapsing due to negative pressure. Depending on the geology, when the screw drill 41 is lowered, the ground water may be pushed away by injecting compressed air from the tip of the screw drill 41. In addition, the gate 17 under the hopper 16 is always open during work so that the crushed stone B can fall freely. The fallen crushed stone B is stacked on the upper surface of the conveyor 18 and eventually becomes immobile.

  FIG. 6 shows a state in which holes H are formed in the ground G in the operation of FIG. On the side peripheral surface of the hole H, a modified region C in which moisture is squeezed out and the density is increased is formed, and the hole H does not collapse rapidly. The ground improvement device 10 can be remotely operated using a controller 15 that transmits information wirelessly. The controller 15 is large enough to be carried by an operator, can operate all the series of operations such as the traveling means 12 and the swivel wheel 11, and does not need to have driving personnel on the body 13. In addition, the body 13 incorporates a control device 14 that receives radio waves from the controller 15 and sends commands to the respective units. Therefore, the worker can adjust the position while holding the controller 15 in the vicinity of the leader mast 29 while observing the positions of the rolling tool 51, the chute 19 and the like. .

  FIG. 7 shows a state where the crushed stone B is being dropped into the hole H formed in the ground G. After forming the hole H as shown in FIG. 6, the crushed stone B is dropped therein. At that time, as shown in FIG. 2, the turning wheel 11 is operated to move the rolling tool 51 directly above the hole H. When the conveyor 18 is operated, the crushed stone B moves forward, slides down the chute 19 and enters the hole H. Note that the tip of the chute 19 is adjacent to the rolling tool 51. Further, by operating the conveyor 18, a gap is created immediately below the gate 17, and the crushed stone B falls from the hopper 16.

  FIG. 8 shows a state in which the crushed stone B is solidified and the stone pillar P is being constructed. As shown in FIG. 7, after the crushed stone B is dropped, the rolling tool 51 is moved downward as shown in this figure, and the pressing body 53 is caused to collide with the upper surface of the crushed stone B to perform tamping. The crushed stone B after the tamping is finished, the gap is reduced, and the stone pillar body P that receives the vertical load is formed by biting into the lower part of the hole H and the side peripheral surface. If a large amount of crushed stone B is dropped at a time, uniform tamping becomes difficult. Therefore, after a certain amount of crushed stone B is dropped and tamped, the compaction tool 51 is once pulled up and crushed stone B is dropped again to form the stone pillar body P in stages. In addition, when the crushed stone B is hardened, compressed air may be supplied from the air hose 50 and sprayed to the outside from the tip of the pressing body 53 in order to prevent negative pressure and push away groundwater.

  FIG. 9 shows a case where the pile S is embedded in the hole H formed in the ground G. When the ground G has a certain support force, the pile S can be embedded instead of the crushed stone B. Since the pile S is embedded at a high density similarly to the stone pillar body P of FIG. 8, the acting compressive load is limited. For this reason, it is possible to use simple products made from thinned wood and contribute to the effective use of forest resources. Note that the pile S can be smoothly embedded in the hole H by using the lifting tool 39. The position of the hanger 39 can be freely adjusted by rotating the boom 35, and it is easy to secure a working space when slung. In addition, the rolling tool 55 that pushes the pile S into the ground has a different shape from those shown in the drawings so far, and the pressing body 56 has a crown shape suitable for the pile S, so that the upper part of the pile S can be easily pushed. Can be restrained.

  FIG. 10 shows a state in which a stone pillar P is formed on the ground G and a building is constructed thereon. Stone pillars P made of crushed stone B are formed on the entire site at regular intervals, and a concrete foundation is placed thereon. Since the stone pillar P penetrates the humus soil having poor proof strength and reaches the viscous soil having sufficient strength, the building is stably supported without being affected by the humus soil. In addition, the stone pillar P is naturally derived, and can be left as it is even when the building is removed later.

  FIG. 11 shows a shape example of the screw drill 41 used in the present invention. The screw drill 41 is composed of a cylindrical body 43 and blades 44 joined to the side peripheral surface thereof, and the body 43 has a function of pushing the earth and sand in the ground G in the horizontal direction, and the tip portion is It is formed in a tapered shape, and the ground G can be pushed out without difficulty. The blades 44 are joined so as to spirally surround the entire side peripheral surface of the body 43, and generate vertical driving force by biting into the ground G. In addition, the blade | wing 44 does not assume scooping up earth and sand on the ground. Therefore, the protruding length of the blade 44 is set to about 1/20 to 1/10 of the maximum diameter of the body 43. Further, a cylindrical central shaft 42 projects on the body 43 in order to receive a rotational force. The total length of the screw drill 41 varies depending on various conditions, but is about 1 meter to 6 meters.

  When the screw drill 41 is buried in the ground G and then pulled out to the ground, the pressure in the vicinity of the tip of the body 43 is lowered, and the hole H may collapse. In order to prevent this, a bit 47 is incorporated in the vicinity of the front end of the body 43. The bit 47 has a conical shape in which a mushroom is turned upside down, and the portion of the stone bump is inserted into the front end surface of the body 43 so that the entire bit 47 can move in the axial direction within a certain range. Yes. An exhaust port 46 is formed on the side peripheral surface of the stone bump. The exhaust port 46 penetrates to the opposite side, and the center portion communicates with the inside of the body 43, so that air can be taken in. In addition, when the bit 47 moves downward, an annular groove 48 is formed at the boundary between the body 43 and the bit 47, and the exhaust port 46 appears on the inner surface.

  When the screw drill 41 is submerged in the ground G, the bit 47 moves backward due to earth pressure, and the annular groove 48 disappears. However, when the screw drill 41 is pulled out from the ground G, the bit 47 moves downward, the exhaust port 46 appears in the inner surface of the annular groove 48, and air is supplied into the ground G to reduce the pressure. To prevent. By providing the annular groove 48, air can be evenly supplied to the entire side peripheral surface. In addition, a joint 45 is screwed onto the upper surface of the central shaft 42 in order to send air into the body 43, and an air hose 50 is attached to the upper portion thereof. The upper half of the joint 45 does not move even when the screw drill 41 is rotating, and the air hose 50 is not twisted.

  When the screw drill 41 is submerged in the ground G having a high groundwater level, the groundwater is pushed away, and thus compressed air that overcomes the groundwater pressure may be injected. In that case, the internal pressure of the body 43 is increased to forcibly push out the bit 47 to expose the exhaust port 46. The function of supplying air to the ground G may also be provided in the rolling tool 51 in addition to the screw drill 41. Further, depending on the conditions, the air hose 50 may not be used to forcibly supply air, but natural ventilation with the screw drill 41 and the rolling tool 51 open may be used.

10 Ground improvement device 11 Turning wheel 12 Traveling means (infinite track)
13 Body 14 Control device 15 Controller 16 Hopper 17 Gate 18 Conveyor 19 Chute 21 Table 22 Hinge 23 Adjustment cylinder 25 Arm 26 Lodging cylinder 27 Pin 29 Leader mast 31 Slider (screw drill side)
32 auger 33 lifting device (screw drill side)
34 Chain 35 Boom 36 Slider (Roller side)
37 Clamper 38 Lifting device (rolling tool side)
39 Lifting tool 41 Screw drill 42 Central shaft 43 Body 44 Blade 45 Joint 46 Exhaust port 47 Bit 48 Annular groove 50 Air hose 51 Compressor 52 Support shaft 53 Press body 55 Compressor (press body is crown-shaped)
56 Press body (crown shape)
B Crushed stone C Modified zone G Ground H Hole P Stone pillar S Pile

Claims (2)

A hole (H) is formed in the ground (G) with a screw drill (41), and a crushed stone (B) or a pile (S) is embedded in the hole (H), and these are pressed with a rolling tool (51, 55). a soil improvement apparatus that,
Traveling means (12) capable of moving freely on rough terrain, body (13) mounted on traveling means (12), leader mast (29) capable of falling down , and movable along leader mast (29) Two sliders (31, 36), an elevating device (33, 38) for individually driving the sliders (31, 36), and the screw drill (41) integrated with one slider (31). An auger (32) to be rotated, a clamper (37) which is integrated with the other slider (36) and holds the rolling tool (51, 55), and a swivel wheel (which can rotate the entire body (13)) 11), a hopper (16) for accommodating the crushed stone (B) embedded in the hole (H), and a chute (19) for feeding the crushed stone (B) in the vicinity of the rolling tool (51, 55). Prepared,
The screw drill (41) includes a cylindrical body (43), a blade (44) that spirally surrounds a side peripheral surface of the body (43), and a rear end of the body (43) protruding from the auger. A central axis (42) inserted into (32) and an exhaust port (46) located near the tip for supplying air into the hole (H) ,
The rolling tool (51, 55) includes a pressing body (53, 56) that collides with the crushed stone (B) or the pile (S), and a clamper protruding from a rear end of the pressing body (53, 56). A support shaft (52) held by (37),
The central shaft (42) and the support shaft (52) are arranged at an equal distance from the rotation center of the swivel wheel (11),
The hopper (16) has a size equivalent to the width of the body (13), thereby eliminating the driver's seat, and as an alternative, the movable controller (15) can remotely control each movable part,
A ground improvement device characterized in that the steps from the formation of the hole (H) to the embedding of the crushed stone (B) or pile (S) can be carried out continuously and repeatedly . The ground improvement device according to claim 1 , further comprising a lifting tool (39) for lifting the pile (S) at an upper portion of the leader mast (29).

Images