JP2019007221A - Tubular pile installation method and tubular pile holding device - Google Patents

Abstract

To provide a method capable of flexibly coping with a need of constructing a pile with a large diameter and a long pile without being affected by a land form and environment of a construction site in an installation of a tubular pile.SOLUTION: In an installation method of this invention, while an excavation device 8 is suspended by a crane, a tubular pile 71 is held by a tubular pile holding device 3 placed on a structure (for example, a pier under construction) fixed onto a ground. Because the tubular pile holding device shares load of the tubular pile to be installed and lifting load of the crane is reduced, increase in crane specification in the construction can be suppressed even when installing a long pile or a pile with a large diameter. Also, when installing the tubular pile, because the tubular pile is held by the tubular pile holding device on the structure fixed onto the ground, a working radius of the crane is not narrowed, if a pile length or pile diameter is enlarged. Thus, a problem that a span length is shortened is not caused. That is, the method can deal with a requirement of long span, even when installing the long pile or the pile with a large diameter. Further, this invention can securely cope with a construction of a remarkably long pile.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a method for driving a tubular pile fitted on the outer periphery of the excavator simultaneously with excavation using a down-the-hole hammer in the excavator, and a tubular pile holding device used in the method. It is suitable for construction sites such as canyons, dam sites, and steep mountainous areas.

(Overview of background technology)
Renewal of social capital such as road bridges, railway bridges, dams, revetments, etc. to cope with the global economic fluidization, industrial structure change, and major changes in weather and geological environment such as abnormal heavy rains, major earthquakes, and tsunamis And new establishments are active. Among such social capital renewal and new construction works, there are many pile driving works that have become larger in diameter and longer, and concrete examples include construction of pier support piles (tubular piles). Is mentioned.

  When construction sites that require this type of placement are in canyons, dams, revetments, rivers, etc., it is usually difficult to carry construction equipment onto the target ground, so a mechanical scaffolding is built at a position away from the ground. However, it is necessary to perform placement using construction equipment carried on the scaffold. However, in a device in which the “pile core position” and the “machine operating range position” are fixed, such as a three-point support pile driving machine, the device does not reach the pile core and construction becomes difficult.

  Therefore, as shown in FIG. 7, a method is employed in which the excavator 8 is suspended by a crane carried into the machine scaffold.

Among the sites where this crane-hanging tubular pile construction method is adopted, for example, road bridges, railway bridge constructions and construction roads and work platforms in deep existing dam sites that are difficult construction routes through deep canyons. In the pier construction for the gantry, as shown in Fig. 7, the pier pile length is extremely long, such as over 60m.
In addition, at the dam site, the members of the dam and the gate are large and heavy, and relatively large cranes (about 150 to 300 t) are used. Therefore, if the vertical load including the crane load and the like becomes large, the pile diameter of the pier becomes larger to support it.

Up to now, due to such various requests, pier construction in canyons and dams, etc., suspends an extremely heavy load excavator using a long and large-diameter tubular pile. As a result, the size of the jetty is also increasing.
Therefore, in recent years when rationalization of public works is strongly promoted, if the span length is shortened, the number of piles will be increased accordingly, leading to adverse effects such as longer construction period, higher costs, and major changes in the ground. For the purpose of shortening, cost reduction, environmental conservation, etc., there are an increasing number of cases that require construction with a longer span length (placement interval) by using large diameter and long piles.

In the future, in response to the selection of routes for the Shinkansen, which is expected to be opened early as a key to economic revitalization, and routes that include difficult construction sections of emergency transport roads that respond to the Great East Japan Earthquake, road bridges and railway bridges included When constructing construction roads and work gantry for tunnel construction, even in difficult construction sections in steep mountainous areas such as the Japanese Alps, the long pile piers only meet the urgency of their construction purpose. Rapid construction is required.
Also, especially in dam lakes, the installation work of the lower reinforcement of the pier will be underwater work at a deep depth, increasing the burden on the operator. A method of increasing the section modulus by using a tubular pile is desired.
In addition, in recent years, serious damage to citizens' lives due to river blockages, natural dams, and debris flows caused by long rainy seasons caused by changes in weather and unusually heavy rains caused by large-scale typhoons in various landslide areas. There is an urgent need for disaster prevention measures to place large-diameter deterrent piles (in many cases tubular piles) in order to deter landslides caused by deep landslides that cause damage. There is no time to enumerate examples of increasing diameter and length.

  Currently, for example, a pile driving method disclosed in Patent Document 1 (Patent No. 37088795) is widely used as an effective rapid construction method in the above environment. In the method disclosed in the patent document, a drilling device including a drill rod is used. A drill bit is provided on the tip end side of the drill rod, and a rotation drive device for rotating the drill rod is provided on the upper end side. In order to drive a tubular pile using such an apparatus, as shown in FIG. 7, an excavator equipped with a rod having a length equal to or longer than the pile length is always required.

(Overview of pier construction)
An example of the pier construction will be described based on FIGS.
FIG. 8 is a plan view showing the conductive material 13 (pier panel) used in the pier construction.
FIG. 9 is a perspective view illustrating one step of the pier construction, and shows a state in which the conductive material 13 (pier panel) shown in FIG. 8 is transported to the design position by a crane.
FIG. 10 is a perspective view showing the next process of FIG. 9, and shows a state in which a tubular pile 71 that forms a pier is placed by using the guide material 13 that is connected so as to protrude from the pier completed part as a guide. Show.

  In the pier construction, a plurality of conductive materials (pier panels) that form one unit of the superstructure of the pier are used. Each guide member (pier panel) functions as a means for guiding the tubular pile to be placed during construction of the pier, and functions as a part of the superstructure after the pier is completed. The conductive material 13 shown in FIG. 8 mainly includes a main frame 14 and a guide frame 15 connected to the main frame.

  The main frame 14 has a connecting member 17 that is connected to an existing conductive material. The guide frame 15 has a cylindrical pile guide 16 that guides the tubular pile to the ground at the time of placing, and a connecting fitting 18 that is connected to the next-stage conductive material. The pile guide 16 has an insertion hole 19 for inserting a tubular pile.

  In constructing a pier using the conductive material 13 having the above-described structure, as shown in FIG. 9, a crane is first prepared on a scaffolding composed of a completed part of the pier, the conductive material 13 is lifted by the crane, and an extension point ( Transport to the end of the pier). Subsequently, the transporting material 13 that has been transported is connected to an existing girder (existing conducting material) on the tip side of the pier completed part, and is cantilevered so as to protrude from the pier completed part as shown in FIG. Extend.

  Next, as shown in FIG. 10, the tubular pile 71 constituting the pier is passed through the pile guide 16 of the extended conductor 13 and is built on the ground at the planned placement position. Subsequently, a drill rod of the excavator 9 described later is inserted through the built-in tubular pile 71. When the tip bit of the drill rod protrudes from the tip of the tubular pile 71, the tubular pile 71 is driven at the same time while rotating the target ground with the drill rod, and then the head of the placed tubular pile 71 is guided to the conductive material 13 Secure to.

  In the example shown in the drawing, every time one conductive material is extended, three tubular piles are driven and these pile heads are fixed to the pile guide 16. Through the above steps, the construction work of the upper structure and the lower structure for one unit (one conductive material) is completed.

  A pier is completed by repeating the process mentioned above and continuing extending the conducting material supported by a plurality of tubular piles.

(Drilling equipment)
Next, based on FIGS. 11 to 13, the principle of the impact press-fitting of the excavator and the tubular pile used in the pier construction described above will be described.

FIG. 11 is a diagram illustrating a configuration of a drilling rig having a down-the-hole hammer.
FIG. 12 is a schematic view showing the principle of impact press-fitting with a down-the-hole hammer.
FIG. 13 is a detailed view showing the principle of impact press-fitting with a down-the-hole hammer.

  As shown in FIG. 11, the excavation apparatus 8 used for placing the tubular pile 71 mainly includes a crane suspension type rotary drive device 80, and a drill rod 85 (excavation shaft member) connected to the rotary drive device 80. It has a down-the-hole hammer 87 incorporating a piston for generating impact pressure input.

  The rotation drive device 80 drives to rotate the long drill rod 85 below the rotation drive device 80. This rotation drive device 80 has a device body 81 for rotation drive and a substantially cylindrical soil removal cap 82 that functions as a soil removal path control means. As shown in FIG. 11, the earth removal cap 82 which is a part of the rotation drive device 80 is fixed to the lower end of the rotation drive device main body 81 so as to surround the upper end side of the drill rod 85. Between the outer peripheral surface of the drill rod 85 of the excavator 8 and the soil removal cap 82, there is a gap for discharging the soil that is blown up by the air lift.

  The drill rod 85 includes a down-the-hole hammer 87 in which a piston for generating a striking pressure is built. The drill rod 85 passes through the inside of the soil removal cap 82 and is operatively connected to the rotary drive device 80.

  On the other hand, an expandable / contractible excavation bit 89 for excavating the ground is provided at the lower end of the drill rod 85 having the down-the-hole hammer 87. An overhanging portion 86 for applying a striking force to the lower portion of the tubular pile 71 (the casing top 75 on the tubular pile side) collides with the outer periphery of the down-the-hole hammer 87 above the excavating bit 89. The mating engaging part) is fixed.

  The excavation bit 89 at the lower end of the excavator is configured to be displaceable (that is, expandable / contractable) between the expanded diameter state and the contracted diameter state. When the excavation bit 89 is in a reduced diameter state, the excavation bit can be freely inserted into and removed from the tubular pile 71. In the expanded state, the excavation bit 89 projects outward, and the turning trajectory of the outer end thereof exceeds the outer diameter of the tubular pile 71 as shown in the enlarged view of FIG.

  At the time of placing the tubular pile 71, as shown in FIG. 12, a drill rod 85 is inserted into the inner space of the tubular pile 71, the drill bit 89 is projected from the opening at the tip, and the drill bit is set in an expanded state. To excavate the target ground.

  When the tubular pile 71 is driven using the excavating device 8 having the above-described configuration, a rotational force is applied to the drill rod 85 by the rotary drive device 80 and at the same time compressed air (compressed air) is applied to the down-the-hole hammer 87 by the compressor. Supply. When the compressed air is supplied to the down-the-hole hammer 87, the piston built in the down-the-hole hammer 87 is driven up and down, and the striking force of the piston is transmitted to the excavation bit 89 at the tip of the hammer. As a result, the hitting excavation can be continuously performed on the ground to be excavated while rotating.

  On the other hand, the driving air (compressed air) supplied toward the down-the-hole hammer 87 not only drives the down-the-hole hammer but also generates an air lift effect inside the tubular pile 71 and is excavated by the excavating bit 89. Blow up the shear (excavated soil) with air. That is, the excavation shear (excavated soil) cut out by the excavation bit 89 is blown up in an air lift manner by riding on the air flow derived from the driving air (compressed air) of the down-the-hole hammer 87 as shown by arrows in FIG.

  As shown by the arrow in FIG. 11, the excavation shear blown up by the air lift effect is the inner space of the tubular pile 71 (specifically, between the inner peripheral surface of the tubular pile 71 and the outer peripheral surface of the drill rod 85). Through the upper end opening of the tubular pile 71, and further guided by the surrounding earth discharge cap 82, and the upper end side outer circumferential surface of the tubular pile and the inner circumferential surface of the earth discharging cap. It ejects from an annular gap formed in plan view. From the viewpoint of securing such a soil removal path, the conventional excavation apparatus has to include a drill rod having a length equal to or longer than the tubular pile to be placed.

  By hitting and excavating the target ground according to the above-described principle, the excavation apparatus 8 advances while accompanying excavation of excavation shear from the upper side of the tubular pile. Then, as shown in FIG. 13, when the excavator digs up, an overhanging portion 86 fixed on the outer peripheral surface below the down-the-hole hammer 87 above the excavating bit 89 and fixed inside the lower end side of the tubular pile 71. The above-described casing top 75 (projected portion / shoe ring) interferes with each other in the vertical direction (collision with each other), and the tubular pile 71 is hit and pressed in the excavation direction.

  Therefore, if the ground is excavated with the drill rod 85 of the excavator 8 inserted into the tubular pile 71, the striking force is simultaneously applied to the lower portion of the tubular pile, and the tubular pile 71 follows the excavator 8. At the same time as the excavation, the blow-in press of the tubular pile proceeds.

Japanese Patent No. 3211673

  As mentioned above, from the viewpoint of shortening the construction period, reducing construction costs, environmental conservation, etc., it is required to reduce the pier support pile placing process, which requires the most cost and time. It is necessary to take a long interval. That is, it is required to drive a large diameter and long pile between long supports.

  On the other hand, when the pile driving construction is performed by the conventional technique, the construction length of the excavator is increased in proportion to the pile length. For example, in order to drive a 60 m tubular pile with the apparatus configuration shown in FIG. 11, a drilling apparatus having a drill rod of 60 m or more is required. In other words, if the pile becomes longer, the excavator (rod part) used for placing the pile will inevitably become longer, and as a result, the amount of suspended load in the pile driving construction increases, resulting in a narrow working radius of the crane. It will be.

The contents will be described in further detail as follows.
First, when performing down-the-hole hammer excavation using a casing together,
・ Drilling shaft member (drill rod) connected below it,
・ Further down diameter hole-type hole hammer connected to the bottom,
・ Casing (tubular piles such as steel pipe piles)
The crane suspends the excavation means that is configured integrally, and excavates at a construction position within the range of the suspension capacity.

At that time, the excavation shaft member portion is inserted into the pipe, and the excavation shaft member is configured such that the upper part of the excavation shaft member is a rotary drive device and the lower part thereof is a state in which the bit portion of the enlarged down-the-hole hammer protrudes from the pipe. Yes. And in this state, the rotary drive device rotates the diameter-expanding bit type down-the-hole hammer via the excavation shaft member connected thereto, and the hit-crushing force of the down-the-hole hammer acts on the entire excavation surface and digs. It has become.
In other words, according to the pile length of the tubular pile, the excavation shaft member (drill rod) is connected and disconnected to change its overall length, thereby ensuring a structure in which the rotary drive device and the excavation bit part always protrude. If the pile becomes longer, the excavation shaft member length becomes longer (and consequently heavier). See FIG.

In addition, as shown in FIG. 13, in tubular pile driving construction in a river part using a down-the-hole hammer 87 or the like, a member 75 referred to as a casing top (overhanging part / schuling) has a pile inward direction at the lower end of the tubular pile. It is provided to protrude.
At the time of excavation and press-fitting by the excavator 8, an overhanging portion 86 (an engagement portion protruding outward) that guides an expandable / contractible excavation bit 89 at the lower end of the apparatus is formed on the casing pile 75 on the tubular pile side (inside The engaging portion that protrudes to the top and bottom) interferes and engages in the vertical direction. That is, the overhanging portion 86 on the excavator side hits the casing top 75 on the tubular pile side in the vertical direction.
The tubular pile 71 at the time of excavation and press-fitting tries to stay high because the vertical movement is constrained by the friction with the surrounding ground (that is, the peripheral surface friction) generated on the peripheral surface. It acts on the tubular pile 71 and is forcibly dragged in the direction of excavation and press-fitted.
Therefore, in the conventional method, during excavation and press-fitting work by the excavation device 8, the excavation device 8 and the tubular pile 71 are configured in a state where they are not fixed in the excavation direction so that the above-described impact press-fitting can be performed. It is configured to be integrally suspended by a crane. See FIG.

In addition, in down-the-hole hammer construction using a casing, the down-the-hole hammer is a mechanism that ejects excavation shear by an air lift using compressed air. It is a flow path.
Therefore, in order to ensure a high pressure of the compressed air that blows up the excavation shear, it is necessary to make the above-mentioned clearance as the flow path as narrow as possible so that the optimum cross-sectional area for the excavation shear blow-up is maintained. As the diameter of the tubular pile increases, the diameter of the drill shaft member (drill rod) increases (and consequently becomes heavier).

  Then, in order to meet the need for larger diameters and longer lengths of piles with conventional technology, (1) the capacity and standards of the crane to be selected are increased in response to the weight that increases in proportion to the pile length and excavation diameter. (2) Shorten the span length, but this is against the demands for shortening the construction period, reducing construction costs, and environmental conservation.

  In addition, in order to meet the needs for increasing the diameter and length of piles, it is necessary to prepare a drilling device equipped with a longer drill rod according to the pile length. When it becomes thick and / or when the rod length becomes remarkably long, it is not possible to cope with it, and there is a possibility that the construction itself becomes impossible.

(Object of the present invention)
In view of the problems and needs described above, the object of the present invention is to provide a method and apparatus that can flexibly meet the needs of large diameter and long construction without being affected by the topography and environment of the construction site when placing a tubular pile. There is to do.

  The above-mentioned purpose is a construction method in which a down-hole drill is used as a drilling device and a tubular pile fitted around the outer periphery of the drilling device is driven simultaneously with excavation. The excavation device is suspended by a crane facility and fixed to the ground. This is achieved by supporting the tubular pile with a tubular pile holding device installed on the object.

  In the tubular pile placing method, for example, the tubular pile being placed may be intermittently supported by the tubular pile holding device during the excavation by the excavator.

  Further, for example, during the excavation by the excavator (during the excavation process), the tubular pile being placed may be pushed and pulled by the tubular pile holding device.

The above purpose is
A fixing portion for fixing the tubular pile holding device to a structure fixed on the ground;
A first chuck portion capable of holding a tubular pile to be driven;
A jack portion for moving the first chuck portion up and down;
A second chuck part that is functionally separated from the first chuck part and the jack part and is capable of holding a tubular pile to be driven;
This is achieved by a tubular pile holding device having

As shown in FIG. 11, when performing pile driving work from a scaffold prepared at a position distant from the target ground, a drilling device having a drill rod having a length equal to or longer than the pile length is required, and thus the conventional method However, the longer the piles to be laid, the more harmful effects were caused such as an increase in crane standards and a reduction in span length.
In contrast, in the placing method of the present invention, as shown in FIG. 1, the excavator is suspended by a crane facility, while the tubular pile is supported by a tubular pile holding device on a structure fixed on the ground. . In other words, since the crane suspension load can be reduced by the tubular pile holding device sharing the load of the tubular pile to be placed, even when placing long and large diameter piles, the crane standards in pile construction can be increased. Can be suppressed.
In addition, since the tubular pile is supported by the tubular pile holding device on the structure fixed on the ground when placing the tubular pile, the crane working radius does not narrow even if the pile length / pile diameter increases, For this reason, there is no adverse effect such as shortening the span length. That is, even when a long and large-diameter pile is driven, it is possible to meet the demand between long spans.
Furthermore, even in the case of construction in which the pile length is remarkably increased, which may be impossible with the conventional technique, the present invention can reliably cope with the construction.
Therefore, according to the present invention, it is possible not only to meet the needs for increasing the diameter and length of the pile, but also to satisfy the demands for shortening the construction period, reducing the construction cost and protecting the environment.

In the present invention, the tubular pile that is being placed is intermittently supported by the tubular pile holding device during the excavation by the excavator (that is, during the excavation process). “Intermittently supporting” means repeating a state where the tubular pile is supported by the tubular pile holding device and a state where the tubular pile is not supported. For example, the tubular pile is intermittently supported by repeating the state in which the tubular pile is chucked by the chuck portion of the tubular pile holding device and the state in which the chuck is released.
This feature protects the tubular pile from falling below a certain length (ie, the vertical movement of the tubular pile is restrained by the tubular pile holding device), and no matter how the tubular pile is lowered. In addition, the drill bit can be continuously unloaded. In addition, it is possible to reliably apply a striking pressure input by a down-the-hole hammer or the like to the tubular pile.
As a result, no matter how high the self-supporting ground (the ground where hole wall collapse etc. does not occur), and no matter how heavy the tubular pile to be placed, the tubular pile will move the excavation bit. There is almost no hindrance, and you can dig and drive smoothly. In other words, the impact pressure input (push-in force) by the down-the-hole hammer is reliably transmitted to the tubular pile, and the functional action of the excavator is not disturbed by the tubular pile, so that the target ground is reliably While being excavated, the tubular pile can be reliably driven.

  Further, in the present invention, during the excavation by the excavator, the tubular pile that is being placed is pushed and pulled by the tubular pile holding device. In other words, because the chucked tubular pile can be moved up and down, the posture and position deviation of the tubular pile generated during the placing work can be corrected and corrected, so that even when the pile length is long, the vertical accuracy of the pile placing is ensured. Can hold.

  In addition, according to the tubular pile holding device of the present invention, it is not necessary to leave the load of the tubular pile in the middle of placing in the crane facility, so even when placing a long and large diameter pile, An increase in crane standards can be suppressed. In other words, it is possible to solve the adverse effects of the conventional technology, such as “the longer the pile to be placed, the greater the crane standard and the shorter the span length”.

It is a side view which shows an example of the tubular pile driving construction method which concerns on this invention. It is the top view and side view which show the tubular pile holding | maintenance apparatus used with a tubular pile placing construction method. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention, and is showing the back process of Drawing 3A. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention, and is showing the back process of Drawing 3B. It is a front view which illustrates one process of the tubular pile driving construction method concerning the present invention, and is showing the back process of Drawing 3C. It is a front view which illustrates one process of the tubular pile driving construction method concerning the present invention, and is showing the back process of Drawing 3D. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention, and is showing the back process of Drawing 3E. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention, and is showing the back process of Drawing 3F. It is a front view which illustrates one process of the tubular pile driving construction method concerning the present invention, and is showing the back process of Drawing 3G. It is a front view which illustrates one process of the tubular pile placing construction method concerning the present invention, Comprising: The post process of Drawing 3H is shown. It is a figure which shows the down-the-hole hammer attachment and excavation apparatus which are used with the tubular pile driving method according to the present invention. It is a figure which shows the specific procedure of the process shown to FIG. 3G. It is a figure which shows the specific procedure of the process shown to FIG. 3H. It is a figure which shows the conventional tubular pile driving construction method. It is a top view which shows the conducting material (pier panel) used by pier construction. It is a perspective view which illustrates one process of jetty construction, Comprising: The mode which has conveyed the guide material shown in FIG. 8 to the design position with the crane is shown. It is a perspective view which shows the next process of FIG. 9, Comprising: The guide material extended in the cantilever shape is utilized for a guide, and it has shown a mode that the tubular pile which makes a bridge pier is driven. It is a figure which shows the principle of the earth removal at the time of tubular pile driving | running | working using an excavation apparatus. It is the schematic which shows the driving | running principle of the steel pipes by the excavation apparatus which comprises a down-the-hole hammer. It is detail drawing which shows the driving | running principle of the steel pipes by the excavation apparatus which comprises a down-the-hole hammer. It is a figure which shows the relationship between the length (pile length) of the tubular pile to drive and the drill rod of a drilling apparatus. It is a figure which shows the relationship between the tubular pile to drive and excavation equipment.

(Outline of tubular pile driving method)
First, the outline of the tubular pile driving method will be described.

  As shown in FIG. 1, the tubular pile driving method is a method in which a tubular pile 71 fitted around the outer periphery of the excavating device 8 is driven on the ground simultaneously with excavation using the down-the-hole hammer.

  FIG. 1 is a view showing a tubular pile driving method (pier construction) using the excavator 8 and the tubular pile holding device 3 together. The tubular pile holding device 3 is different from the conventional tubular pile placing method (pier construction) shown in FIGS. 7 and 10 in that the tubular pile holding device 3 is used.

  In the tubular pile placing method of the present embodiment, the excavator 8 is suspended by crane equipment such as a crawler crane, while the tubular pile 71 is supported by the tubular pile holding device 3 on the structure fixed on the ground. . In this application, the “structure fixed on the ground” is, for example, a bridge in the middle of construction, and more specifically, a pier in the middle of construction as illustrated in FIG. 9 or FIG. 10 is given as a specific example. It is done.

  As in the prior art shown in FIG. 11, the “excavator 8” used in this embodiment includes at least a crane-suspended rotary drive device 80 and a drill rod 85 (excavation shaft member) connected to the rotary drive device 80. ), A down-the-hole hammer 87 incorporating a piston for generating impact pressure input, and an excavation bit 89 configured to be able to expand and contract. Regarding the details of the configuration of the excavator 8 and the functional action, the description of the prior art described above is used, and the description thereof is omitted here.

  The configuration of the “tubular pile holding device 3” used in the present embodiment is as follows.

(Outline of tubular pile holding device)
The tubular pile holding device 3 used in the present embodiment is a so-called placement assisting device, and the tubular pile follows using a long excavation device 8 than a tubular pile to be placed (steel pipe pile forming a bridge pier). It is used when excavating.

As shown in FIG. 2, this tubular pile holding device 3
A fixing portion 31 for fixing the tubular pile holding device to the “structure fixed on the ground”;
A hydraulically driven upper chuck portion 33 and a lower chuck portion 35 capable of holding a tubular pile;
A hydraulically driven jack portion 37 for moving the upper chuck portion 33 up and down;
have.

  The fixing portion 31 is located on the bottom side of the tubular pile holding device 3 and plays a role of fixing the tubular pile holding device to a bridge in the middle of construction (for example, a jetty in the middle of construction).

  The upper chuck portion 33 (first chuck portion) is configured to be able to hold a tubular pile in a state where the excavator 8 is inserted. The tubular pile is chucked (held) by the upper chuck portion 33 in a state where the upper chuck portion 33 is in pressure contact with the outer peripheral surface of the tubular pile. If the upper chuck part 33 is separated from the outer peripheral surface of the tubular pile from the state where the upper chuck part 33 chucks the tubular pile, the chuck (holding) by the upper chuck part 33 is released. Moreover, the upper chuck | zipper part 33 has the inner side space which can insert a tubular pile in the inner side.

  Similarly, the lower chuck portion 35 (second chuck portion) is configured to be able to hold a tubular pile in a state where the excavation device 8 is inserted. The tubular pile is chucked (held) by the lower chuck portion 35 in a state where the lower chuck portion 35 is in pressure contact with the outer peripheral surface of the tubular pile. If the lower chuck part 35 is separated from the outer peripheral surface of the tubular pile from the state where the lower chuck part 35 chucks the tubular pile, the chuck (holding) by the lower chuck part 35 is released. Moreover, the lower chuck | zipper part 35 has the inner side space which can insert a tubular pile in the inner side.

  The lower chuck part 35 is functionally separated from the upper chuck part 33 and the jack part 37. That is, the upper and lower chuck portions 33 and 35 are independent in operation and operation when chucking / releasing the tubular pile. Further, the influence of the load and impact on the lower chuck portion 35 does not affect the functions of the upper chuck portion 33 and the jack portion 37.

  Moreover, the tubular pile holding | maintenance apparatus 3 has the control part (controller) for controlling any one or two or more of the jack part 37, the upper chuck | zipper part 33, and the lower chuck | zipper part 35 manually or automatically besides the said structure. It has.

(Details of tubular pile driving method)
Next, a tubular pile placing method using the excavator 8 and the tubular pile holding device 3 will be specifically described. Steps A to I described below correspond to FIGS. 3A to 3I.

  In the following description, pier construction is illustrated as a specific construction example using the tubular pile driving method. Regarding the specific procedure of the pier construction and the structure of the main members used for the pier construction, the explanation of the prior art described above is used, and the explanation here is omitted. In addition, as a specific example of the “structure fixed to the ground” on which the tubular pile holding device 3 is installed, a jetty in the middle of construction is illustrated. Further, it is assumed that a crawler crane as shown in FIG. 1 is used as a specific example of the crane equipment used in the pier construction.

  Hereinafter, mainly based on FIG. 3A-FIG. 3I, the process A-process I of a tubular pile placing construction method are demonstrated in order.

(Process A)
In the same manner as the prior art shown in FIG. 9, the guide material 13 (pier panel) is connected to the pier completed portion so as to protrude from the pier completed portion (structure fixed on the ground). Thereby, the conducting material 13 functions as a part of the “structure fixed on the ground”.
A connecting member 12 (a companion flange) for connecting a tubular pile holding device to be described later is attached in advance to the guide frame 15 of the conducting material 13 to be connected.

(Process B)
The tubular pile 71 to be placed is built on the ground by passing the tubular pile 71 through the pile guide 16 provided in the guide frame 15 of the conductive material 13. In addition, in FIG. 3, the tubular pile is shown with the broken line so that it may be easy to discriminate | determine.

(Process C)
The tubular pile holding device 3 is suspended by a crane and installed on the conductive material 13 projecting from the pier completion part. The conductive material 13 (pier panel) is a part of the “structure fixed on the ground”. That is, the tubular pile holding device 3 is fixed on a bridge in the middle of construction.
At this time, the tubular pile 71 is inserted into the inner space of the upper chuck portion 33 and the lower chuck portion 35. In addition, the fixing portion of the tubular pile holding device 3 is fixed to the connecting member 17 (complex flange) attached to the guide frame 15 of the conductive material 13.

(Process D)
The tubular pile is built on the ground through the tubular piles 72 and 73 through the other pile guides included in the guide frame 15 of the conductive material 13 in the same procedure as in the process B described above.

(Process E)
A down-the-hole hammer attachment 9 that is a component of the excavator 8 is inserted. The down-the-hole hammer attachment 9 includes at least one or a plurality of drill rods 85, a down-the-hole hammer 87, and a drill bit 89 that can be expanded / reduced in diameter as shown in the enlarged view of FIG. 4 (a). It is configured.
In addition, the excavation apparatus 8 used by this embodiment can change the full length by adding and cutting | disconnecting a drilling shaft member (drill rod) according to the pile length of a tubular pile. That is, since the weight of the excavator increases according to the pile length, the weight of the excavator is not necessarily constant. Further, the structure is such that a configuration in which the rotary drive device and the excavation bit part always protrude can be secured. See FIG.

(Process F)
The upper pile is joint welded to the built-in tubular pile 71. Further, the rotary drive device 80 is connected to the down-the-hole hammer attachment 9 inserted into the tubular pile 71. Thereby, the state which inserted the excavation apparatus 8 longer than the tubular pile to drive in to this tubular pile is ensured. FIG. 4 (b) shows an enlarged view of the excavator 8 configured by connecting the rotary drive device 80 to the down-the-hole hammer attachment 9. FIG.

(Process G)
The tubular pile 71 is pulled up by the tubular pile holding device 3 to expand the diameter of the excavation bit 89. The specific procedure is shown in FIG.
First, as shown in FIG. 5A, the upper chuck portion 33 holds the outer peripheral surface of the tubular pile 71. That is, the tubular pile 71 is chucked by the upper chuck portion 33. The lower chuck portion 35 remains in the non-chuck state.
Next, the jack portion 37 is operated to push up the upper chuck portion 33 that chucks the outer peripheral surface of the tubular pile 71. As a result, the tubular pile 71 is pulled up by the stroke of the jack portion 37 while being chucked by the upper chuck portion 33. As a result, as shown in FIG. 5 (b), the lower end of the tubular pile 71 is separated from the ground, and a state in which the excavation bit 89 of the excavator 8 protrudes from the lower end of the tubular pile 71 is ensured. Further, as shown in FIG. 5 (b), a gap X of a predetermined distance (a gap having a size allowing the diameter expansion operation of the excavation bit 89) is formed between the lower end of the tubular pile 71 and the ground surface.
Next, as shown in FIG. 5 (c), the diameter of the excavation bit 89 at the lower end of the excavator 8 is expanded through the gap X. In a state where the excavation bit 89 has expanded in diameter, the excavation bit protrudes outside the tubular pile 71 through the gap X.
Through the above procedure, a state in which the tubular pile 71 to be placed is fitted over the outer periphery of the excavator is ensured.
In the conventional method, the excavator 8 and the tubular pile 71 are always suspended integrally by a crane due to the above function of the tubular pile holding device 3 having the chuck portions 33 and 35. On the other hand, in the present embodiment, the weight of the tubular pile can be held by the tubular pile holding device 3, and the crane can mainly support (hold) the weight of only the excavating device 8 in the subsequent work. A structure that can be shared and held is secured.

(Process H)
The tubular pile 71 is driven to a predetermined depth by drilling a rock pile or the like by the down-the-hole hammer 87 provided in the excavating device 8 and pushing the tubular pile 71 by the tubular pile holding device 3.
Specifically, the upper chuck portion 33 of the tubular pile holding device 3 is separated from the tubular pile 71 after the excavation bit 89 is expanded in the previous step and before the excavation by the excavation apparatus 8 is started. And, the operation of the excavation bit 89 protruding from the lower end of the tubular pile 71 is placed so that the tubular pile does not interfere with the excavation of the excavator 8 and the follow-up of the tubular pile 71 with respect to the excavator. Excavation by the excavator 8 is advanced while the intermediate pile 71 is held or released by the lower chuck portion 35 of the tubular pile holder 3.
During the excavation by the excavator 8, the conductive material 13 on which the tubular pile holding device 3 is installed functions as a member that guides the tubular pile 71. This is the same as the prior art shown in FIG.

  The timing of repeating the chuck and the release thereof by the tubular pile holding device 3 is not particularly limited. For example, the following timing can be adopted.

As shown in FIG. 6 (a), excavation proceeds while the tubular pile 71 is chucked by the lower chuck portion 35 of the tubular pile holding device 3. The chuck by the upper chuck portion 33 remains released. In addition, since the lower chuck part 35 is functionally separated from the upper chuck part 33 and the jack part 37, the jack part 37 of the tubular pile holding device 3 may be damaged due to an impact caused by the hit of the down-the-hole hammer 87. There is no.
Since the tubular pile 71 that fits the outer periphery of the excavating apparatus is held by the tubular pile holding apparatus 3, when excavation proceeds in the chuck state of FIG. 6 (a), as shown in the lower part of FIG. 6 (b), the excavation progresses. The overhanging portion 86 of the excavating device 8 hits the casing top 75 at the lower end of the tubular pile 71. That is, when the tubular pile 71 is still chucked by the lower chuck portion 35 of the tubular pile holding device 3, the excavation of the excavating device 8 and the follow-up of the tubular pile 71 with respect to the excavating device eventually hold the tubular pile holding the tubular pile. It will be obstructed by the device 3.
Therefore, as shown in FIG. 6 (b), when the tubular pile holding device 3 starts or prevents the excavation of the excavator 8 and the follow-up of the tubular pile 71 to the excavator, The chuck part 35 is released from the tubular pile 71 to release the chuck. And excavation is advanced in the state which released the chuck | zipper with respect to the tubular pile 71. FIG. As a result, excavation by the excavator 8 proceeds so that the tubular pile 71 follows the impact force of the down-the-hole hammer 87 (so that the tubular pile 71 follows the excavation bit 89). The driving principle at this time is the same as that of the prior art shown in FIGS.
When excavation proceeds in the non-chucked state of FIG. 6 (b), the lower end of the tubular pile 71 eventually hits the expanded excavation bit 89 as shown in the lower part of FIG. 6 (c). That is, if the chuck for the tubular pile 71 is left released, the lower end portion of the tubular pile 71 rides on the excavation bit 89 and hinders the operation (rotation, striking, etc.) of the excavation bit. This point has been described above as a problem of the prior art as shown in FIG.
Therefore, as shown in FIG. 6 (c), the lower chuck portion 35 of the tubular pile holding device 3 is used when the excavation bit 89 protruding from the lower end of the tubular pile 71 begins to interfere with or before the excavation bit 89 begins to obstruct the operation. Then, the tubular pile is chucked again.
When the excavation is advanced in the chuck state of FIG. 6 (c), the tubular pile 71 that fits around the outer periphery of the excavator is held by the tubular pile holding device 3, so that as shown in FIG. 6 (d) again, the excavation proceeds. The overhanging portion 86 of the excavating device 3 hits the casing top 75 at the lower end of the tubular pile 71. That is, when the tubular pile 71 is still chucked by the lower chuck portion 35 of the tubular pile holding device 3, the excavation of the excavating device 8 and the follow-up of the tubular pile 71 with respect to the excavating device eventually hold the tubular pile holding the tubular pile. It will be obstructed by the device 3.
Thereafter, in the same manner, excavation proceeds while repeating the release and re-chucking of the tubular pile 71. In other words, the operation of the excavation bit 89 protruding from the lower end of the tubular pile 71 is not disturbed by the tubular pile 71, and the excavation of the excavator 8 and the follow-up of the tubular pile 71 to the excavator are not obstructed. While the tubular pile 71 in the middle of installation is intermittently chucked by the lower chuck portion 35 of the tubular pile holding device 3 (repeating chucking by the lower chuck portion 35 and its release), excavation by the excavating device 8 is advanced.

  In addition, the chuck | zipper with respect to the tubular pile 71 mentioned above and its cancellation | release can be operated by an operator's judgment according to the vibration and resistance value at the time of placement, the impact sound of a down-the-hole hammer, and other conditions, It is also possible to perform automatic control based on the vibration and resistance value of the hour, the hammering sound of the down-the-hole hammer, and other situations.

  Moreover, in the process mentioned above, the chuck | zipper with respect to the tubular pile 71 and its cancellation | release are performed using the lower chuck | zipper part 35 of the tubular pile holding | maintenance apparatus 3, However, according to the progress of the operation | work in the middle of excavation by the excavation apparatus 8, it is appropriate. The tubular pile 71 in the middle of placing may be pushed into the excavation hole by the tubular pile holding device 3. When lowering the tubular pile 71 in the middle of placing, the tubular pile 71 is chucked by the upper chuck portion 33 of the tubular pile holding device 3, and the upper chuck portion 33 (and the tubular pile 71 chucked thereto) is jacked by the jack portion 37. Following the excavation, the tube is piled down into the borehole and gradually lowered into the borehole. At that time, the chuck by the lower chuck portion 35 remains released.

  Further, during the placement of the tubular pile 71, the load of the excavating device 8 is supported by a crane as shown in FIG. 1, and the load of the tubular pile 71 to be placed is supported by the tubular pile holding device 3.

(Process I)
When the tubular pile 71 is driven to a predetermined depth, the excavator 8 is pulled out from the tubular pile.

  Thereafter, the tubular pile holding device 3 is moved, and other tubular piles 72 and 73 are driven in the same manner as the tubular pile 71 is driven.

(Other embodiments)
In embodiment mentioned above, although the case where this invention was applied to the pile driving in a pier construction was illustrated, embodiment of this invention is not limited to this.

  That is, in the above-described embodiment, the pier in the middle of construction as a “structure fixed on the ground” for installing the tubular pile holding device, more specifically, a conductive material connected so as to project from the pier completed portion is illustrated. However, the “structure fixed on the ground” is not limited to this. For example, a structure such as a work gantry, artificial ground, and a bridge can be used as a “structure fixed on the ground”.

3 Tubular pile holding device 8 Drilling device 9 Down-the-hole hammer attachment 12 Connecting member (Companion flange)
13 Guide material (pier panel)
14 Main frame 15 Guide frame 16 Pile guide 17 Connection member 18 Connection bracket 19 Insertion hole 31 Fixing part (installation part)
33 Upper chuck (first chuck)
35 Lower chuck part (second chuck part)
37 Jack part 71 Tubular pile (steel pipe pile)
72 Tubular pile (steel pipe pile)
73 Tubular pile (steel pipe pile)
75 Casing top (overhang / shoe ring)
80 Rotation Drive Device 81 Device Main Body 82 Earth Removal Cap 85 Drill Rod (Excavation Shaft Member)
86 Overhang part (engagement part)
87 Down the Hole Hammer 89 Drilling Bit

Claims (4)

  In the construction method that uses a down-the-hole hammer for the excavator and at the same time excavating a tubular pile that is fitted around the outer periphery of the excavator on the ground, the excavator was suspended by a crane facility and installed on a structure fixed on the ground. A tubular pile placing method characterized by supporting a tubular pile with a tubular pile holding device.   The tubular pile driving method according to claim 1, wherein the tubular pile in the middle of placing is intermittently supported by the tubular pile holding device during the excavation by the excavator.   The tubular pile placing method according to claim 1 or 2, wherein the tubular pile being placed is pushed and pulled by the tubular pile holding device during the excavation by the excavator. In the tubular pile holding device used in the construction method according to claim 1,
A fixing portion for fixing the tubular pile holding device to a structure fixed on the ground;
A first chuck portion capable of holding a tubular pile to be driven;
A jack portion for moving the first chuck portion up and down;
A second chuck part that is functionally separated from the first chuck part and the jack part and is capable of holding a tubular pile to be driven;
A tubular pile holding device.