Pile material press-in mechanism using ground improvement construction machine and driving method thereof

Abstract

To provide a pile material press-in mechanism and a driving method using a ground improvement construction machine for pile materials such as wooden piles that are difficult to drive in by rotation.SOLUTION: After penetration, a chuck part 53 is loosened to lower a swivel head 4, and after changing grip to grip a lower part of an earth auger 5, tongs are used to extend a piston rod 121 of a pile pressing hydraulic cylinder 12, and a pile pressing cover 14 is used to penetrate a pile material 13 to the required depth. According to the driving method of the present invention, the pile pressing force of the pile pressing hydraulic cylinder 12 acts on the swivel head 4, but this is offset by the pulling force acting on the earth auger 5 by a screw 52 that has dug into the ground, achieving a balance between action and reaction forces.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pile driving mechanism and a driving method thereof, which utilizes a ground improvement construction machine having a rotary penetration mechanism. More specifically, the present invention relates to a driving method for driving piles that support architectural and civil engineering structures. [Background technology]

[0002] Ground improvement construction machines with rotary penetration mechanisms, primarily used for ground improvement work, do not inherently have mechanisms for driving concrete without rotary pressure, and therefore cannot be used to drive piles that cannot be driven by rotary pressure. Wooden piles are also a type of pile material that cannot be driven by rotary pressure, but their use is increasingly becoming an environmentally friendly pile material from the perspective of CO2 reduction. Wooden piles are made from thinned wood that has been treated with preservatives and other methods. In particular, the use of wooden piles reduces CO2 emissions compared to the use of cement or steel, and also protects forests. Wooden piles have long been used to support architectural and civil engineering structures. Typically, stripped wood is used in tapered or cylindrical shapes. As piles, they require a certain level of bearing capacity (allowable vertical bearing capacity). Therefore, ultimately, each wooden pile must be able to achieve a specified bearing capacity or higher through pressure-in or other methods.

[0003] Although not limited to wooden piles, a method of driving piles using a hydraulic cylinder is also known. When driving a pile, a reaction force is required to obtain the required bearing capacity, but the weight of the pile driver alone is usually insufficient to provide the reaction force. Patent Document 1 discloses a pile driving mechanism and method that uses an earth auger to ensure reaction force when driving a pile. This pile driving mechanism and method involves drilling a guide hole 5 in the ground with an earth auger 4, inserting a pile 6 into the guide hole 5, and then pressing the head of the pile 6 into the ground with a pile cap 34 of a drifter 3. Furthermore, the screw 40 of the earth auger 4, which is rotationally driven by the drifter 3, engages with the ground G to ensure reaction force, and the pile cap 34 then drives the pile 6 into the ground.

[0004] The press-in machine for the pile pressing method of Patent Document 2 has a mounting frame 8 fixed to a piston rod 7 of a cylinder mechanism 5 provided on a frame (leader) 3. A casing 9 is rotatably attached to this mounting frame 8, and a chuck mechanism is built into this casing 9. The chuck mechanism grips and fixes a pile 10, and the cylinder mechanism 5 presses the pile 10 into the ground. The reaction force at this time is absorbed by a separately provided reaction support member 4, which is an auger screw, fixed to the ground. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6192085 [Patent Document 2] Japanese Patent Application Publication No. 52-71807 Summary of the Invention [Problem to be solved by the invention]

[0006] The pile driving mechanism and pile driving method described in Patent Document 1 involves driving a pile 6 by moving a drifter 3 and pressing the head of the pile 6 with a pile cap 34. To accomplish this, the pile 6 is driven in by the feed (vertical feed mechanism) of the drifter 3, which has a drive chain. Because of the drive chain, there is a limit to the driving force, and the feed mechanism is overloaded, preventing sufficient bearing capacity. Furthermore, the reaction support member 4, which is the auger screw of the driving machine in Patent Document 2, is a reaction mechanism and does not have the function of drilling holes, so construction is only possible in ground that can drive the pile 10 without pilot holes.

[0007] The present invention has been made in view of the above background to achieve the following objects. An object of the present invention is to provide a pile pressing mechanism and a driving method using a ground improvement construction machine for pile materials such as wooden piles that are difficult to insert by rotation. Another object of the present invention is to provide a pile driving mechanism and a driving method thereof that utilizes a ground improvement construction machine that can provide sufficient bearing capacity. Yet another object of the present invention is to provide a pile driving mechanism and a driving method thereof that utilizes a ground improvement construction machine and that does not place an excessive load on the machine. [Means for solving the problem]

[0008] The pile driving mechanism of the present invention 1 comprises a vehicle body equipped with a leader that is set up vertically, an earth auger rotation drive means that is driven up and down along the leader by a feed means and moves to rotate an earth auger, a swivel head having a chuck mechanism that grips and fixes the shaft of the earth auger, and a feed means for driving the swivel head up and down on the leader, and is characterized in that it comprises pile driving means that a pile pressing hydraulic cylinder is fixed to the housing of the swivel head, and a pile pressing lid that is fixed to the piston rod of the pile pressing hydraulic cylinder and that drives the upper end of the pile material into the ground.

[0009] The pile driving method using the pile driving mechanism described in the present invention 1 includes a pile core setting step (1) of aligning the center line of the earth auger with the ground where the pile is to be driven, a preliminary excavation step (2) of drilling a hole in the ground with the earth auger, an earth auger pulling out and shifting step (3) of pulling out the earth auger from the ground to the surface and shifting the leader from the drilled hole, a pile material lifting and setting step (4) of setting the pile material held by the pile pressing cover on the drilled hole, and a step of screwing the earth auger into the ground and setting the earth auger. The earth auger rotation drive means is rotated to move the swivel head downward by the feed means, and the pile material is penetrated into the drilled hole by the pile pressing cover (5); and after the penetration, the feed means is driven to move the swivel head downward, and the lower part of the earth auger is gripped by the chuck for re-gripping, and then the piston rod of the pile pressing hydraulic cylinder is extended to press the pile pressing cover (7). [Effects of the Invention]

[0010] According to the pile driving mechanism and driving method using the ground improvement construction machine of the present invention, the pile pushing force from the pile pushing hydraulic cylinder acts on the swivel head, but this is offset by the pulling force acting on the earth auger by the screw that has dug into the ground, thereby balancing the action and reaction forces. This prevents the leader side of the ground improvement construction machine from lifting up, allowing the pile to be driven in smoothly. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an overall front view showing a state in which a leader of a pile pressing mechanism using a soil improvement construction machine according to a first embodiment of the present invention is erected. [Figure 2] FIG. 2 is a right side view of FIG. [Figure 3] FIG. 3 is a plan view of FIG. [Figure 4] FIG. 4 is a perspective view of FIG. 1 as seen from the upper right. [Figure 5] FIG. 5 is a longitudinal sectional view of the swivel head and hydraulic cylinder of FIG. [Figure 6] FIG. 6 is a longitudinal cross-sectional view of the swivel head and leader of FIG. [Figure 7] FIG. 7 is an explanatory diagram showing pile driving steps 1 to 4 according to the present invention. [Figure 8] FIG. 8 is an explanatory diagram showing steps 5 to 9 of driving piles according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] A first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is an overall front view showing the leader of a pile driving mechanism using a ground improvement construction machine according to the first embodiment of the present invention in an upright position, Fig. 2 is a right side view of Fig. 1, and Fig. 3 is a plan view of Fig. 2. Fig. 4 is a perspective view of Fig. 1 seen from the upper right, Fig. 5 is a vertical cross-sectional view of the swivel head and hydraulic cylinder of Fig. 4, and Fig. 6 is a vertical cross-sectional view of the swivel head and leader of Fig. 4. As shown in Figs. 1 to 6, the ground improvement construction machine 1 includes a construction machine main body 2, a leader 3 of the construction machine main body 2 whose angle is adjustable, a swivel head 4 which is an excavation drive unit that moves up and down along the leader 3, and an earth auger 5 which is detachably attached to the swivel head 4 and which bores holes in the ground.

[0013] The construction machine body 2 is a crawler type and is equipped with a cab 6, which serves as a swivel unit. The cab 6 can rotate around a swivel base 7. The angle of the leader 3 can be adjusted by extending and retracting the piston rod of an angle-adjusting hydraulic cylinder 8 attached to the front of the cab 6. The leader 3 is equipped with a winch 9, which serves as a lifting means for hoisting a pile 13 to be driven into the ground with a wire 91 via a top sheave 92. The swivel head 4 can be raised and lowered via a drive chain mechanism 10 (see Figure 6). A through-hole 51 is provided in the center of the swivel head 4, penetrating it in a direction parallel to the leader 3. The through-hole 51 has an inner diameter slightly larger than the outer diameter of the upper shaft of the earth auger 5. This allows the earth auger 5 to slide relative to the swivel head 4 with its shaft, excluding the screw 52 attached to its tip, inserted through the through-hole 51.

[0014] A chuck portion 53 that chucks the earth auger 5 is provided on the top of the swivel head 4. The chuck portion 53 can perform a chucking operation for the earth auger 5 and an operation to release the chucking state. With the earth auger 5 chucked, the hydraulic motor 54 is rotated, and the screw 52 drills a hole in the ground.

[0015] A support bracket 11 is fixed to the right side of the housing of the swivel head 4 (as viewed in Figure 1), protruding from the right side, and a pile-pressing hydraulic cylinder 12 is fixed vertically to the right side of the support bracket 11. A pile-pressing lid 14 is fixed to the lower end of the piston rod 121 of the pile-pressing hydraulic cylinder 12, for pressing the upper end of the pile material 13. The pile material 13 is made of wood or other materials that are difficult to insert by rotation. A recess 141 is provided on the underside of the pile-pressing lid 14, into which the upper end surface of the pile material 13 is fitted. The upper side of the earth auger 5 is inserted through the through-hole 51 of the swivel head 4, and the upper side of the earth auger 5 is gripped by a chuck part 53 and attached facing vertically.

[0016] The ground improvement construction machine 1 is placed on the ground G at a predetermined location where ground improvement work is to be performed. During construction, the leader 3 is set in a vertical direction. The swivel head 4 can be moved vertically (up and down) along the leader 3 by a drive chain mechanism 10 (see Figure 6). The swivel head 4 descends while rotating the earth auger 5, allowing the screw 52 at the lower end to drill a drilling hole (see Figure 7) 21 in the ground G. In the case of soft ground, the step of drilling the drilling hole 21 can be omitted.

[0017] After drilling hole 21 with screw 52, ​​earth auger 5 is removed from drilling hole 21 and swivel base 7 of cab 6 is rotated by the required angle, which shifts earth auger 5 from drilling hole 21 and aligns pile pressing lid 14 to a position above drilling hole 21. In other words, the axis of earth auger 5 and the axis of pile pressing lid 14 are located on the same circumference centered on the rotation center of swivel base 7 of cab 6, making centering easy. In this state, pile material 13 is hoisted with winch 9 and set on pile pressing lid 14, and by lowering pile material 13, its tip can be aligned with drilling hole 21.

[0018] Next, the pile driving process of the present invention will be described with reference to FIGS. (1) Construction step 1 in Figure 7 (piles core setting) The center line of the earth auger 5 of the ground improvement construction machine 1 is placed on the ground G where concrete is to be poured. The earth auger 5 is chucked by the chuck portion 53 of the swivel head 4, which has been raised to the required height of the leader 3, and is set in the vertical direction. (2) Construction process 2 in Figure 7 (pre-digging with earth auger) While rotating the earth auger 5, the swivel head 4 is lowered to a required height, and a drilled hole 21 of a required depth is formed in the ground G with the screw 52 at the tip of the earth auger 5. (3) Construction process 3 in Figure 7 (earth auger removal and shifting) The earth auger 5 is rotated in the same direction as in (2) above while the swivel head 4 is raised and the screw 52 is removed from the drilled hole 21. Then, the operator's cab 6 is rotated by the required angle to move the earth auger 5 away from the drilled hole 21, thereby positioning the pile pressing cover 14 above the drilled hole 21, i.e., above the vertical line passing through the center of the drilled hole 21.

[0019] (4) Construction step 4 in Figure 7 (piles hanging set) The pile 13 is hung by the wire of the winch 9, and the top surface of the pile 13 is fitted into the recess 141 of the pile pressing lid 14, so that the pile 13 is set in a hanging position in the vertical direction, and the wire is removed from the pile 13. As a result, the tip of the pile 13 is positioned at the center of the drilled hole 21. (5) Construction step 5 in Figure 8 (penetration of pile material 13 by rotating earth auger) The earth auger 5 is screwed into the ground, and the hydraulic motor 54 is rotated to rotate the screw 52 of the earth auger 5, lowering the swivel head 4 to the required height, and the pile pressing cover 14 is used to penetrate the pile material 13 into the drilled hole 21. Then, as shown in construction step 6 in Figure 8, the piston rod 121 of the pile pressing hydraulic cylinder 12 is extended, and the pile material 13 is penetrated to the bottom of the drilled hole 21.

[0020] (6) Construction step 7 in Figure 8 (re-gripping and penetration using hydraulic cylinder for pile pressing) After the penetration, the chuck 53 is loosened to raise the swivel head 4, and the lower part of the earth auger 5 is gripped. Then, using pliers (not shown), the piston rod 121 of the pile-pushing hydraulic cylinder 12 is extended, and the pile-pushing cap 14 is used to drive the pile 13 to the required depth. According to the driving method of the present invention, the pile-pushing force of the pile-pushing hydraulic cylinder 12 acts on the swivel head 4, but this is offset by the pulling force acting on the earth auger 5 by the screw 52 that has dug into the ground, achieving a balance between action and reaction. Completion of the penetration is determined by the magnitude of the pressure supplied to the pile-pushing hydraulic cylinder 12 and whether the pliers have penetrated to the required depth. Then, as shown in construction step 9, the earth auger 5 is rotated in the reverse direction to raise the swivel head 4 to the required height, completing the penetration of the pile 13. [Explanation of symbols]

[0021] 1…Ground improvement construction machine 2…Construction machine body 3...Leader 4...Swivel head 5...Earth Ogre 51...Through hole 52...Screw 53...Chuck part 54...Hydraulic motor 6...Driver's cab 7...Swivel 8...Angle adjustment hydraulic cylinder 9...winch 91...Wire 92...Top sheave 10...Drive chain mechanism 11...Support bracket 12...Hydraulic cylinder for pressing piles 121...Piston rod 13…Pile material 14...Pile pressing cover 141...recess 21...Drilling hole

Claims

1. a vehicle body provided with a vertically erected reader; a swivel head having an earth auger rotation drive means that is driven by a feed means to move up and down along the leader and rotate the earth auger, and a chuck mechanism that grips and fixes the shaft of the earth auger; a feed means for driving the swivel head up and down on the reader; In the pile pressing mechanism comprising: a pile pressing means comprising a pile pressing hydraulic cylinder fixed to the housing of the swivel head and a pile pressing lid fixed to the piston rod of the pile pressing hydraulic cylinder for pressing the upper end of the pile material into the ground; A pile pressing mechanism comprising:

2. The pile driving method using the pile pressing mechanism according to claim 1 is as follows: A pile core setting process (1) in which the center line of the earth auger is aligned with the ground where the pile material is to be installed; A preliminary excavation process (2) of drilling the ground with the earth auger; An earth auger extraction and shifting process (3) of extracting the earth auger from the ground to the surface and shifting the leader from the drilled hole; A pile material hanging setting process (4) of setting the pile material held by the pile pressing lid on the drilled hole; A penetration step (5) by rotating the earth auger, in which the earth auger is screwed into the ground, the earth auger rotation drive means is rotated, the swivel head is moved downward by the feed means, and the pile material is penetrated into the drilled hole with the pile pressing cover; After the penetration, the feed means is driven, the swivel head is moved downward, and the chuck is used to grip the lower part of the earth auger. Then, the piston rod of the pile pressing hydraulic cylinder is extended to press the pile pressing cover. This is a step (7) of a re-grasping and pile pressing hydraulic cylinder penetration step. A pile driving method comprising:

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