JP3683229B2 - Existing pile removal method and equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for removing an existing pile buried in the ground.
[0002]
[Prior art]
Conventionally, there are two methods for removing existing piles buried in the ground: a method of pulling out as it is and a method of removing it after partially breaking. There are many cases of hanging piles.
[0003]
As a pulling method, for example, a vibro hammer suspended by a crane is connected to the head of an existing pile by a chuck device, and the existing pile is lifted by a crane together with the vibro hammer and pulled out by using the vertical motion generated by the vibro hammer. Or, rotate the auger casing with a bit attached to the tip while rotating it around the existing pile, cut the friction between the existing pile and the ground, pull out the auger casing, and then use the crane For example, a method of pulling out a pile, excavating the periphery of the pile with a casing, and pulling the wire set in the casing to hang it on the pile.
[0004]
In the former method using vibro hammer, vibration and noise during operation are large, and it is difficult to construct in urban areas considering the impact on nearby residents, etc. Also, the latter auger casing is pulled out and collected. Later, in order to pull out the existing pile, after pulling out the auger casing, the surrounding ground collapses and fills in the gap created around the existing pile, and as a result, the frictional resistance of the existing pile increases and cannot be pulled out as it is. Sometimes it will be.
[0005]
In addition, by rotating the auger casing with a bit attached to the tip and surrounding it around the existing pile, cutting the friction between the existing pile and the ground, the auger casing rotates around the pile. As a result, the pile often rotates together with the casing and the casing head, and the pile cannot be cut.
[0006]
Furthermore, both methods require a large-scale crane with high lifting gravity for lifting a vibro hammer and existing piles, which not only increases the construction cost but also restricts the place where it can be constructed.
[0007]
On the other hand, in the method of removing after partially rupturing, a casing provided with a so-called inner cutter is used, and the reinforcing bars of the existing pile are cut with the casing and the inner cutter, and the debris removing means such as a hammer grab is used. Remove.
[0008]
The underground pile removing apparatus disclosed in JP-A-8-120671 is one of them, and as shown in FIGS. 7 to 10, the existing pile 1 made of concrete having a reinforcing bar embedded in the ground is removed. The excavation casing 3 is formed by projecting the excavation cutter 3a on the lower edge and the cutter 2 in the cylinder, and the erection device for supporting the excavation casing 3 on the upper portion of the pile so as to be rotatable and press-fitted. 11 and a hammer grab 13 as a debris removing means for taking out the treated pile in the excavation casing 3.
[0009]
A crane 12 is installed on the ground, the hammer grab 13 is suspended from the crane 12, and the erection device 11 and the crane 12 are connected by a bar 14.
[0010]
A plurality of the cutters 2 are attached to a bed 2a welded to the excavation casing 3, and the bed 2a is composed of a triangular stay 2b provided above and below, and a triangular stay 2c provided on a side surface of the bed 2a. Strongly supported.
[0011]
Further, the cutters 2 provided at the four locations are provided with steps in the mounting depth. Further, the four cutters 2 have different protrusion lengths. In other words, the lowermost cutter 2 protrudes most, and the uppermost cutter 2 protrudes less.
[0012]
When removing the existing pile 1 buried in the ground by the device, first, the erection device 11 is installed directly above the existing pile 1 to be removed. Then, the excavation casing 3 is set in the erection device 11 to apply rotation and pressure. Then, the cutter 2 advances by crushing the whole while cutting the rebar 10 of the pile 1.
[0013]
In this way, the necessary depth, that is, the existing pile 1 is removed to such an extent that the original construction is not hindered. Thereafter, the hammer grab 13 is lowered into the excavation casing 3 to discharge the debris and earth and sand inside.
[0014]
[Problems to be solved by the invention]
In the underground pile removing apparatus disclosed in JP-A-8-120671, since the cutter 2 is cut from the top surface of the pile 1, excavation becomes extremely difficult, and a great deal of time is spent on breaking the pile 1.
[0015]
In JP-A-8-120671, it is assumed that the pile 1 is cut at a necessary position, and a movable cutter (copy cutter) is provided on the inner side of the pile 1 so as to be able to advance and retreat in addition to the fixed cutter 2 described above. Although the embodiment is also described, this movable cutter is provided in a bed equipped with a hydraulic cylinder and can be projected and retracted in a horizontal direction, and a hydraulic pressure is applied to the bed with a high-pressure hose. In addition, a hydraulic swivel is required, and if a high-pressure hose is inserted into the casing, the effective use of the inner diameter of the casing is hindered.In addition, operations such as adding a hose according to the addition of the casing, installing and removing the swivel device, etc. Increased and work efficiency is poor.
[0016]
Moreover, since the movable cutter (copy cutter) is movable, it is difficult to make the cutter itself and the mechanism that supports it robust enough to cut concrete and rebar, and the cutter is symmetrical to the inner circumference of the casing. Even if two pieces are provided, the burden on one cutter is large for cutting the rebar, and it is difficult to cut the rebar easily.
[0017]
The object of the present invention is to eliminate the inconvenience of the conventional example, and the pile can be removed without greatly excavating the periphery of the pile, so there is no risk of harming the residential environment such as neighboring residents due to sound and vibration, etc. Even if there are reinforcing bars in the pile, it can be cut reliably, and since it can be cut at the required depth without destroying the entire pile, the existing pile can greatly improve work efficiency An object of the present invention is to provide a removal method and apparatus.
[0018]
[Means for Solving the Problems]
Since the present invention to achieve the object, as the removal method of the existing pile, the existing by eccentric existing pile with rocking rotated by like an anchor device excavation casing projecting from the cutter into the casing head peripheral surface Insert it into the ground to the cutting position so as to surround it without contacting the pile , then rotate the excavation casing all around and cut the existing pile horizontally from the outer periphery with the cutter and treat it with debris removal means such as hammer grab The gist is to take out the existing piles.
[0019]
The existing pile removing device is a device for removing an existing pile buried in the ground, a drilling casing having a cutter projecting from the inner peripheral surface of the casing head, and this casing around the existing pile. It is composed of a built-in device that supports swinging and rotation, and debris removing means such as a hammer grab for taking out the existing treated pile in the casing, so that the cutter fits within a half circumference on the inner peripheral surface of the casing head. at intervals, and sequentially the side-by-side as the protrusion length is long, among a plurality with arranging side by side, all or part of the inner periphery of the casing head than concrete cover thickness of from rebar existing pile the projection length from the face as large, it is an gist arranging largest ones so as to sequentially turn the protrusion length at the left and right at the center is reduced.
[0020]
According to the first and second aspects of the present invention, at a position surrounding the existing pile with respect to the existing pile, the excavation casing and the casing head are set at the eccentric position, and the position where the pile is to be cut (depth Insert it into the ground while rocking and rotating until At this time, the cutter protruding from the inner peripheral surface of the casing head does not contact the existing pile. Next, when the position to be cut is reached, if the excavation casing is rotated all around, the cutter that does not hit it hits the outer circumference of the existing pile and cuts horizontally from the outer circumference. Then, the existing piles that have been treated with debris removal means such as hammer grabs are taken out.
[0021]
Further, since the excavation is rocking excavation, it is possible to reliably excavate the periphery of the pile up to a position where it is desired to cut and rotate and cut at that position.
[0022]
And since the cutter was made to be accommodated in the inner circumference of the casing within the half circumference, the casing head can be swung and rotated without bringing the cutter into contact with the existing pile if the other half circumference surface is brought close to the existing pile. In addition, the cutters are arranged side by side so that their lengths are longer and are arranged side by side, so that it becomes like a saw wave, and it is ensured by deeply biting into the existing piles one after another. Can be cut. Furthermore, since it is lined up side by side, it becomes a cut that makes a cut along the side, and it can be cut surely and quickly compared to the case where the existing pile is broken up and down.
[0023]
Moreover, a cutter can be reliably applied to the reinforcing bar of an existing pile, and this reinforcing bar can be cut | disconnected reliably.
[0024]
In addition, by arranging the largest cutters in the center so that the protruding lengths are sequentially reduced on the left and right, the existing cutters are gradually deeper from the smallest to the largest even if the casing is rotated in either direction. By cutting into the pile, it can be cut reliably.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view showing a first embodiment of an existing pile removing apparatus of the present invention, FIG. 2 is a plan view of the same, and the same components as those in FIGS. It is attached.
[0027]
In the figure, 3 is a digging casing, and a casing head 3b is fitted to the front end of the main body 3c that is added to the required length on the way, and the fitting portion is fastened with a bolt 4. The casing head 3b is provided with an excavation cutter 3a at the lower end.
[0028]
This excavation casing 3 is supported by an erection device 11 so as to be swingable and rotatable as shown in FIGS. As is well known, this erection device 11 is a press-fitting machine used in, for example, the all-casing method, and a chuck device 5 for tightening the outer periphery of the excavation casing 3 in a ring shape on the reaction force frame 9 and the chuck device 5 are rotationally driven. A driving device 6 such as a motor 6a and a speed reducer 6b, and an elevating cylinder 7 using a hydraulic cylinder that moves the chuck device 5 and the driving device 6 up and down are provided. In the figure, 8 indicates an outrigger by a horizontal jack on which the erection device 11 is installed horizontally.
[0029]
The excavation casing 3 is rotationally propelled while being chucked on the outer periphery by the erection device 11 and inserted into the ground.
[0030]
In the present invention, in addition to such a structure, the inner peripheral surface of the casing head 3b at the tip of the excavating casing 3 is spaced so that the cutters 15a, 15b,. Are arranged in a row, side by side. These cutters 15a, 15b,... 15e are claw-like ones having sharp blades made of a hard metal that is harder than the metal constituting the digging casing 3, and are firmly attached to the inner peripheral surface of the casing head 3b by welding or the like. It sticks to.
[0031]
The cutters 15a, 15b,... 15e are all or part of a plurality (in the example shown, the inner circumference of the casing head 3b is more than the concrete cover thickness h from the reinforcing bar 10 of the existing pile 1 except for the cutter 15a). The projecting length from the surface is large.
[0032]
In the present embodiment, the cutters are arranged so that the protruding lengths are sequentially increased from the smallest cutter 15a.
[0033]
The number of the cutters 15a, 15b,... 15e is determined by the diameter of the casing head 3b, and the diameter of the casing head 3b is a combination of the diameter of the existing pile 1 and the length of the maximum length cutter 15e and the gap length more uniformly. And
[0034]
Next, the method of the present invention for removing the existing pile 1 using the excavation casing 3 will be described. Here, the existing pile 1 shows the concrete pile (Prefabricated piles, such as PC and RC, field construction pile) which has a reinforcing bar inside as a structure embed | buried in the ground. The diameter of the existing pile 1 that can be processed depends on the diameter of the excavation casing 3, but is preferably within a few meters from the viewpoint of ease of processing.
[0035]
The erection device 11 is installed above the existing pile 1 that has been buried, and the excavation casing 3 and the casing head 3b are set at a position eccentric to the existing pile 1. In this case, as shown in FIG. 2, the existing pile 1 approaches the inner peripheral surface of the excavation casing 3 away from the cutters 15a, 15b,.
[0036]
The outer periphery of the excavation casing 3 is fastened and fixed by the chuck device 5 of the erection device 11, and the chuck device 5 is rotated to the left and right by the driving device 6, and at the same time the lifting cylinder 7 is freed. The head 3b is inserted into the ground of the outer peripheral portion so as to surround the existing pile 1.
[0037]
The excavation with the excavation casing 3 is performed to a depth (several meters) at which the existing pile 1 is to be cut. The depth of several meters is a length by which the weight of the cut existing pile 1 can be taken out by the hammer grab 13.
[0038]
When the position of several meters to be cut is reached, the excavation casing 3 is rotated all around in one direction by the erection device 11.
[0039]
As a result, the cutters 15a, 15b,... 15e are inserted into the outer periphery of the existing pile 1 in order from the shorter cutter 15a, and the existing pile 1 is cut from the outer periphery as shown in FIG. The reinforcing bars 10 are cut by the cutting of the cutters 15a, 15b,... 15e, and the existing pile 1 is cut into a square shape. The thickness of the cutters 15a, 15b,... 15e is preferably 50 to 100 mm.
[0040]
The already-existing pile 1 thus cut is grasped and removed by a debris removing means such as a hammer grab 13 suspended from the crane 12.
[0041]
FIG. 5 shows a second embodiment of the present invention. In the cutters 15a, 15b, 15c, and 15d, the largest cutter 15d is arranged in the center so that the protruding lengths are sequentially reduced from left to right. The largest cutter 15d has blades facing both the left and right sides, and the other blades face toward the shorter ones.
[0042]
Thus, the cutters 15a, 15b, 15c, and 15d have a length of l ₄ <l ₃ <l ₂ <l ₁ so that they can be easily inserted, and 2 to 3 pieces (15b, 15c, 15d) of these are reinforcing bars 10 Therefore, the protruding length from the inner peripheral surface of the casing head 3b is made larger than the concrete cover thickness h from the reinforcing bar 10 of the existing pile 1.
[0043]
The diameter (inner diameter D) of the casing head 3b is determined by the pile diameter d of the existing pile 1 + the length l ₁ + α (gap) of the cutter 15d.
[0044]
In the case of the second embodiment, the entire rotation of the excavation casing 3 for cutting the existing pile 1 may be either left or right.
[0045]
【The invention's effect】
As described above, the method and apparatus for removing an existing pile according to the present invention can remove a pile without greatly excavating the periphery of the pile. In addition, even if there is a reinforcing bar in the pile, it can be cut reliably, and further, it can be cut at the required depth without destroying the entire pile, which can greatly improve the work efficiency. It can be done.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing a first embodiment of an existing pile removing apparatus of the present invention.
FIG. 2 is a plan view showing a first embodiment of an existing pile removing apparatus of the present invention.
FIG. 3 is a side view showing an erection device and excavation casing used in the existing pile removing device of the present invention.
FIG. 4 is a plan view showing an embedding device and a digging casing used in the existing pile removing device of the present invention.
FIG. 5 is a plan view showing a second embodiment of the existing pile removing apparatus of the present invention.
FIG. 6 is an explanatory view showing a method for removing an existing pile according to the present invention.
FIG. 7 is a perspective view showing a conventional example.
FIG. 8 is a plan view of a conventional example.
FIG. 9 is a vertical side view of a conventional example.
FIG. 10 is a schematic view showing a construction state of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pile 2 ... Cutter 2a ... Bed 2b ... Stay 2c ... Stay 3 ... Excavation casing 3a ... Excavation cutter 3b ... Casing head 3c ... Main part 4 ... Bolt 5 ... Chuck device 6 ... Drive device 6a ... Motor 6b ... Reduction gear 7 ... Elevating cylinder 8 ... Outrigger 9 ... Reaction force frame 10 ... Reinforcing bar 11 ... Built-in device 12 ... Crane 13 ... Hammer grab 14 ... Bar 15a, 15b, ... 15e ... Cutter

Claims (2)

The excavated casing with a cutter projecting on the inner peripheral surface of the casing head is inserted into the ground to the cutting position so as to surround the existing pile without eccentrically contacting the existing pile while swinging and rotating with the erection device, A method for removing an existing pile, wherein the excavating casing is rotated all around, the existing pile is cut horizontally from the outer periphery with the cutter, and the existing pile treated with a debris removing means such as a hammer grab is taken out. An apparatus for removing an existing pile buried in the ground, and a drilling casing having a cutter projecting from an inner peripheral surface of a casing head, and supporting the casing around the existing pile in a swingable and rotatable manner a device like an anchor, is composed of a rubble removal means such as a hammer grab retrieve the processed existing pile of the casing, said cutter at intervals to fit within the half in the casing head peripheral surface, and, side by side so as to sequentially its projection length is longer, of the plurality with arranging side by side, the whole or a part preparative large projection length from the peripheral surface in the casing head than concrete cover thickness of from rebar existing pile An existing pile removing apparatus , wherein the largest ones are arranged in the center so that the protruding lengths are sequentially reduced on the left and right.

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