Pile driving mechanism and construction method using a ground improvement construction machine

Abstract

This is a pile driving mechanism and driving method that utilizes a ground improvement construction machine for pile materials that are difficult to drive in by rotation, such as wooden piles. After penetration, the chuck part 53 is loosened to lower the swivel head 4, and the lower part of the earth auger 5 is gripped and replaced, and then pliers are used to extend the piston rod 121 of the pile pressing hydraulic cylinder 12, and the pile pressing cover 14 is used to penetrate the pile material 13 to the required depth. According to the driving method of the present invention, the pile material pressing force from 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 the screw 52 that has dug into the ground, making it possible to balance the action and reaction forces.

Description

[Technical field]

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

[0002] Ground improvement construction machines with a rotary penetration mechanism, which are mainly used for ground improvement, do not have a driving mechanism by non-rotary pressing, and cannot be used for driving pile materials that cannot be driven by rotary penetration. Wooden piles are also a pile material that cannot be driven by rotary penetration, but their use as environmentally friendly pile materials is increasing from the perspective of reducing CO2. Wooden piles made from thinned wood that has been treated with preservatives are used as support piles. In particular, the use of wooden piles reduces CO2 more than the use of cement and steel materials, and also protects forests. Wooden piles have been used as pile materials to support architectural and civil engineering structures for a long time. Generally, tapered or cylindrical piles with the bark removed are used. Since they are piles, a certain level of bearing capacity (allowable vertical bearing capacity) is required. For this reason, it is ultimately necessary to ensure that each wooden pile can obtain a bearing capacity greater than the specified level by pressing in, etc.

[0003] Although not limited to wooden piles, a pile driving method using a hydraulic cylinder is also known. When driving a pile, a reaction force is necessary to obtain the required bearing force, but usually the reaction force is insufficient only with the weight of the pile driver. Patent Document 1 discloses a pile driving mechanism and a pile driving method that secure a reaction force with an earth auger when driving a pile. This pile driving mechanism and pile driving method drills a guide hole 5 in the ground with an earth auger 4, inserts a pile 6 into the guide hole 5, and presses the head of the pile 6 with a pile cap 34 of a drifter 3 to drive it in. Furthermore, the screw 40 of the earth auger 4, which is rotated by the drifter 3, bites into the ground G to secure a reaction force, and further drives the pile 6 with the pile cap 34.

[0004] The pressing 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 pile 10 is gripped and fixed by the chuck mechanism, and the pile 10 is pressed into the ground by the cylinder mechanism 5. The reaction force at this time is absorbed by a reaction support member 4, which is a separately provided 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] In the pile material pressing mechanism and pile material pressing method described in Patent Document 1, when pressing in the pile 6, the pile cap 34 presses the head of the pile 6 by moving the drifter 3 to press in the pile. For this reason, the pile 6 is pressed in by the feed (vertical feed mechanism) of the drifter 3 having a drive chain, and since the drive chain is used, there is a limit to the pressing force, and the feed mechanism is overloaded, so sufficient support force cannot be obtained. In addition, the reaction support member 4, which is the auger screw of the pressing machine in Patent Document 2, is a reaction mechanism and does not have the function of drilling holes, so construction can only be done in ground that allows the pile 10 to be driven in without pilot holes.

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

[0008] The pile material pressing mechanism described in the present invention 1 is as follows: Equipped with a vertically installed reader Construction machine body and, an earth auger rotation drive means that is driven to move up and down along the leader and rotates the earth auger; and A chuck mechanism is provided to hold and fix the shaft of the earth auger. Swivel head and for driving the swivel head up and down on the reader; Drive Chain Mechanism and In the pile pressing mechanism, The present invention is characterized in that it has a pile pressing means consisting of a pile pressing hydraulic cylinder fixed to the housing of the swivel head and a pile pressing cover fixed to the piston rod of the pile pressing hydraulic cylinder for pressing the upper end of the pile material into the ground.

[0009] Using the pile material pressing mechanism described in the present invention 1 Invention 1 The pile driving construction method is as follows: A pile core setting process (1) in which the center line of the earth auger is aligned with the ground on which the pile material is to be driven; A preliminary digging process (2) of drilling a hole in the ground with the earth auger; an earth auger removal / shift process (3) for removing the earth auger from the ground to the ground surface and shifting the leader from the drilled hole; The pile pressing lid is placed on the drilled hole. The above A pile material hanging and setting process (4) for setting the pile material; The earth auger is screwed into the ground, and the earth auger rotary drive means is rotated to rotate the swivel head to the Drive Chain Mechanism A penetration step (5) by rotating the earth auger, in which the pile material is penetrated into the drilled hole by the pile pressing lid; After the penetration, Drive Chain Mechanism The swivel head is driven to move downward, and the chuck mechanism After the lower part of the earth auger is gripped, the pile pressing hydraulic cylinder is P Extend the stone rod The screw of the earth auger, which is dug into the ground, counteracts the pulling force acting on it, balancing the action and reaction forces. The pile pressing cover is pressed by a hydraulic cylinder penetration process for replacing and pressing the pile ( 6 ) A pile driving method comprising the steps of: Effect 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 driving force from the pile driving hydraulic cylinder acts on the swivel head, but the screw that has dug into the ground is offset by the pulling force acting on the earth auger, and the action and reaction forces can be balanced. This makes it possible to prevent the leader side of the ground improvement construction machine from floating up, and allows the pile to be driven in smoothly. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an overall front view showing a state in which a leader of a pile driving mechanism utilizing a ground improvement construction machine according to a first embodiment of the present invention is in an upright position. [Diagram 2] FIG. 2 is a right side view of FIG. [Diagram 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. [Diagram 5] FIG. 5 is a vertical 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 pile driving steps 5 to 9 according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall front view showing a state in which a leader of a pile material pressing mechanism using a ground improvement construction machine according to the first embodiment of the present invention is erected, 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 seen from the upper right of FIG. 1, 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 FIG. 1 to FIG. 6, the ground improvement construction machine 1 includes a construction machine body 2, a leader 3 of the construction machine body 2 that is adjustable in angle, a swivel head 4 that is an excavation drive unit that moves up and down along the leader 3, and an earth auger 5 that is detachably attached to the swivel head 4 and forms a hole in the ground.

[0013] The construction machine body 2 is a crawler type and has a cab 6 which is 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 has a winch 9 which is a hoisting means for hoisting a pile 13 to be driven into the ground with a wire 91 through a top sheave 92. The swivel head 4 can be raised and lowered via a drive chain mechanism (see FIG. 6). A through hole 51 is provided in the center of the swivel head 4, penetrating in a direction parallel to the leader 3. The through hole 51 has an inner diameter slightly larger than the outer diameter of the shaft on the upper side of the earth auger 5. As a result, the earth auger 5 can slide relatively to the swivel head 4 with the shaft, excluding the screw 52 provided at the tip, passing through the through hole 51.

[0014] A chuck portion 53 for chucking the earth auger 5 is provided on the upper portion of the swivel head 4. The chuck portion 53 can perform a chucking operation and an unchucking operation for the earth auger 5. 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 housing of the swivel head 4 on the right side (as viewed in FIG. 1) and protrudes from the right side. A pile pressing hydraulic cylinder 12 is fixed vertically to the right side of the support bracket 11. A pile pressing lid 14 for pressing the upper end of the pile material 13 is fixed to the lower end of the piston rod 121 of the pile pressing hydraulic cylinder 12. The pile material 13 is made of wood or other pile material that is difficult to insert by rotation. The lower surface of the pile pressing lid 14 is provided with a recess 141 into which the upper end surface of the pile material 13 is fitted. The upper side of the earth auger 5 is passed 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 the vertical direction. The swivel head 4 can be moved vertically (up and down) along the leader 3 by the drive chain mechanism 10 (see FIG. 6). The swivel head 4 descends while rotating the earth auger 5, so that the screw 52 at the lower end can drill a drilling hole (see FIG. 7) 21 in the ground G. In the case of soft ground, the process of drilling the drilling hole 21 can be omitted.

[0017] After drilling the drilling hole 21 with the screw 52, ​​the earth auger 5 is removed from the drilling hole 21 and the swivel base 7 of the cab 6 is rotated at a required angle, whereby the earth auger 5 is shifted from the drilling hole 21 and the pile pressing lid 14 can be aligned to a position above the drilling hole 21. That is, the shaft cores of the earth auger 5 and the pile pressing lid 14 are arranged on the same circumference centered on the rotation center of the swivel base 7 of the cab 6, making centering easy. In this state, the pile material 13 is hung by the winch 9 and set on the pile pressing lid 14, and the pile material 13 is lowered to align its tip with the 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 (pile core setting) The center line of the earth auger 5 of the ground improvement construction machine 1 is set on the ground G 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 seat 6 is rotated by a required angle to shift the earth auger 5 away from the drilled hole 21, so that the pile pressing lid 14 is positioned 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 to set the pile 13 in a vertically hanging state, 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 of Figure 8, the piston rod 121 of the pile pressing hydraulic cylinder 12 is extended, and the pile material 13 is inserted to the bottom of the drilled hole 21.

[0020] (6) Construction step 7 in Figure 8 (penetration using hydraulic cylinder for pile replacement and pile pressing) After the penetration, the chuck part 53 is loosened to raise the swivel head 4, and the lower part of the earth auger 5 is gripped and replaced. Then, pliers (not shown) are used to extend the piston rod 121 of the pile pressing hydraulic cylinder 12, and the pile pressing cover 14 penetrates the pile material 13 to the required depth. According to the driving method of the present invention, the pile material pressing force of the pile pressing hydraulic cylinder 12 acts on the swivel head 4, but the screw 52 that has dug into the ground is offset by the pulling force acting on the earth auger 5, so that the action and reaction forces can be balanced. The completion of penetration is determined by the magnitude of the pressure supplied to the pile pressing hydraulic cylinder 12 and whether the pliers have penetrated to a specified depth. Thereafter, as shown in construction step 9, the earth auger 5 is rotated in the reverse direction to raise the swivel head 4 to a specified height, and the penetration of the pile material 13 is completed. [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 stand 8...Hydraulic cylinder for angle adjustment 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 construction machine body having a vertically erected reader; an earth auger rotation drive means that is driven to move up and down along the leader and rotates the earth auger; and A chuck mechanism is provided to hold and fix the shaft of the earth auger. Swivel head and a drive chain mechanism for driving the swivel head up and down on the reader; In the pile pressing mechanism comprising: a pile pressing means including a pile pressing hydraulic cylinder fixed to the housing of the swivel head and a pile pressing lid fixed to a piston rod of the pile pressing hydraulic cylinder for pressing an upper end of the pile material into the ground; A pile pressing mechanism comprising:

2. The pile driving method using the pile driving 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 on which the pile material is to be driven; A preliminary digging process (2) of drilling a hole in the ground with the earth auger; An earth auger extraction and shifting process (3) of extracting the earth auger from the ground to the ground surface and shifting the leader from the drilled hole; A pile material hanging and 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 to move the swivel head downward by the drive chain mechanism, and the pile material is penetrated into the drilled hole by the pile pressing lid; After the penetration, the drive chain mechanism is driven, the swivel head is moved to the lower part, and the lower part of the earth auger is gripped by the chuck mechanism. Then, the piston rod of the pile pressing hydraulic cylinder is extended to counterbalance the pulling force acting on the screw of the earth auger that has dug into the ground, and the pile pressing cover is pressed while balancing the action and reaction forces. F. A pile driving method comprising the steps of:

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