JP2007192017A - Bridge pier anchoring structure and bridge pier construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bridge pier anchoring structure sufficiently exhibiting required anchoring strength with simple constitution. <P>SOLUTION: An annular first anchor member 40 is placed on the upper end of a cylindrical precast concrete pile 10, and an upper end of a PC steel member 12 of the pile 10 is anchored to the first anchor member 40. The first anchor member 40 is extended radially inside of the pile 10, and the intermediate parts of anchor bolts 31 are joined to the extended part. The upper ends of the anchor bolts 31 are joined to a steel bridge pier 20. A second anchor member 50 is disposed at the lower ends of the anchor bolts 31. Concrete is placed on the upper side from the second anchor member 50, and the bridge pier 20 is placed on the first anchor member 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure for fixing a steel pier to a pile and a construction method thereof.

In civil engineering structures such as bridges, it is required to reliably transmit the force transmitted from the pedestal to the foundation in the ground. For example, a steel structure called an anchor frame has been conventionally used as one of fixing structures for that purpose (see Patent Document 1, etc.). The anchor frame includes two upper and lower anchor beams and is disposed inside the foundation pile below the pedestal. Each anchor beam has two webs and two flanges to form a square cross section, and the web is provided with a number of vertical ribs. The upper end of the vertical anchor bolt is joined to the base of the pedestal, the middle is joined to the upper anchor beam, and the lower end is joined to the lower anchor beam.
JP 2004-225411 A JP 2004-190266 A JP 2005-299291 A

  The conventional anchor frame is designed to resist a predetermined load using only steel, requires two webs, two flanges, and a large number of ribs, and has a large number of parts. Manufacturing man-hours such as welding work between members are also large, and the manufacturing cost is high. On the other hand, the inside of the foundation pile is filled with concrete. An anchor frame is embedded in the concrete. Since this concrete also bears the cross-sectional strength, it can be said that it is an uneconomic design.

The present invention has been made to solve the above problems,
It is a structure that anchors a steel pier to a pile made of cylindrical precast concrete containing PC steel,
Anchor bolts whose upper end is joined to the pier and whose lower end is inserted into the pile,
A first anchor member installed at an upper end portion of the pile and extending radially inward from the pile and engaged (supported) with an intermediate portion of the anchor bolt;
A second anchor member disposed inside the pile and engaged with a lower end of the anchor bolt;
And concrete is filled in the upper part of the pile.
Accordingly, it is possible to provide a fixing structure that can sufficiently exhibit the required fixing strength with a simple configuration. Moreover, since the load of a bridge pier can be supported by a pile via a 1st anchor member (or an anchor bolt and a 1st anchor member), without passing the concrete with which the inside of a pile is filled, the said filling concrete It is possible to proceed with the installation work of the pier without waiting for it to completely harden, and to improve the efficiency of construction.

The concrete is preferably filled in the pile above the depth at which the second anchor member is buried in the concrete, and filled in the pile above the lower end of the anchor bolt. Preferably it is.
It is desirable that the first anchor member is joined to the PC steel material of the pile.
The first anchor member is preferably a fixing portion of the PC steel material of the pile.
The pier may be placed on the first anchor member.

The first anchor member preferably has an annular bottom portion, a peripheral wall provided on the outer periphery of the bottom portion, and a plurality of vertical ribs erected at intervals in the circumferential direction of the bottom portion. . As a result, the configuration can be simplified and the strength can be easily secured.
The bottom portion may be placed on the upper end surface of the pile to fix the upper end portion of the PC steel material, and may be extended radially inward from the pile and engaged with an intermediate portion of the anchor bolt.
The pier may be placed on the upper edge of the vertical rib.

The first anchor member includes an annular pile head installation portion installed at an upper end portion of the pile, and an anchor that is extended radially inward from the pile head installation portion and thus the pile and is engaged with the anchor bolt. Engaging portion.
It is preferable that the PC steel material of the said pile is joined to the said pile head installation part.
It is desirable that the pile head installation part is a fixing part of the PC steel material of the pile.
The pier may be placed on the anchor engaging portion.
The said pile head installation part may have a cyclic | annular bottom part, the surrounding wall provided in the outer periphery of this bottom part, and the some vertical rib erected at intervals in the circumferential direction of the said bottom part. It is preferable that the bottom portion is placed on the upper end surface of the pile to fix the upper end portion of the PC steel material.
Furthermore, the said pile head installation part may have the cyclic | annular upper board part arrange | positioned on the said surrounding wall and several vertical rib.

The pile head installation portion and the anchor engagement portion of the first anchor member may be integrally connected. As a result, the number of members can be reduced.
In this integrated structure, the bottom portion and the vertical rib of the pile head installation portion extend radially inward from the inner periphery of the pile, and the extended portion of the bottom portion and the vertical rib serves as the anchor engaging portion. You may comprise. In this case, it is preferable that the anchor bolt is engaged with the extending portion of the bottom portion. Moreover, the base part of the said pier may be installed in the upper end edge of the extension part of the said bottom part and a vertical rib.
Furthermore, in the integrated structure, the pile head installation portion includes the upper plate portion, and the upper plate portion extends radially inward from the inner periphery of the pile to be a component of the anchor engaging portion. It may be. In this case, the anchor bolt may be engaged with the extending portion of the bottom portion, or may be engaged with the extending portion of the upper plate portion. Moreover, the base part of the said pier may be installed in the upper surface of the extension part of the said upper board part.

By the way, in the integrated structure, the position of the first anchor member is usually fixed to the pile, and the position of the anchor bolt is fixed to the first anchor member. Accordingly, if the pile is displaced in the circumferential direction from the normal position due to construction errors, the horizontal or vertical position is deviated, or tilted with respect to the vertical, the first anchor member and the anchor Similarly, bolts must be installed at positions that deviate from their normal positions, and it is difficult to avoid construction errors for bridge piers.
Thus, for example, it is conceivable that the anchor bolt is engaged with the anchor engaging portion so that the position of the anchor bolt can be adjusted by making the anchor bolt insertion hole of the anchor engaging portion a hole. If it does so, even if a pile and the 1st anchor member have shifted | deviated from the regular position, about an anchor bolt, it can install in a regular position, and the construction error of a bridge pier can be avoided by extension.
However, there are usually a large number of anchor bolts per pier, and it is extremely complicated to position each one of these many anchor bolts at a proper position on the construction site, which increases the required construction period and costs. May also increase.

As a countermeasure against such construction errors, the pile head installation portion and the anchor engagement portion of the first anchor member may have a separate structure instead of the integral structure. That is, the anchor engaging portion of the first anchor member may be installed separately from the pile head installation portion so as to be capable of adjusting the relative position on the pile head installation portion.
By this, if there is an error in the construction of the pile, the pile head installation part of the first anchor member can be installed in accordance with the position of the pile, while the anchor engagement part can be installed at a regular position, As a result, an anchor bolt can be installed in a regular position. As a result, it is possible to avoid construction errors from occurring on the pier.

In the separate structure, it is preferable that the anchor engaging portion has an annular shape having an outer diameter larger than an inner diameter of the pile head installation portion and a smaller inner diameter. Thereby, an anchor engaging part can be easily mounted on a pile head installation part in the state extended from the pile head installation part to the radial inside.
The outer diameter of the anchor engaging portion is preferably smaller than the outer diameter of the pile head installation portion, but is not limited thereto, and may be the same diameter as the outer diameter of the pile head installation portion, or the pile. The diameter may be larger than the outer diameter of the head installation portion.

In the separate structure, the pile head installation portion is provided with a plurality of temporary fixing arrangement portions arranged in the circumferential direction so as to be arranged so that the temporary fixing members for the anchor engaging portions can be adjusted in the radial direction. Is preferred.
Thus, after the anchor engaging portion is installed with the relative position adjusted with respect to the pile head installing portion, the anchor engaging portion can be temporarily fixed at the adjusted position. Therefore, it is possible to reliably prevent the anchor engaging portion and the anchor bolt and thus the pier from being displaced from the normal positions during the concrete placement, curing and the like.
A base portion of the pier is installed on the anchor engaging portion, and at least a part of the plurality of temporary fixing members arranged in the plurality of temporary fixing arrangement portions can temporarily fix the base portion of the pier. More preferably.
Thus, after the pier is installed, the pier can be temporarily fixed to the pile head installation part until the concrete is hardened, and the pier is more sure to be displaced from the normal position. Can be prevented.
The outer diameter of the pile head installation portion is larger than the outer diameter of the anchor engagement portion, and the temporary fixing arrangement portion is provided radially outward from the installation portion of the anchor engagement portion in the pile head installation portion. It is preferable.

The said separate structure WHEREIN: It is preferable that the jack part which can raise / lower the said anchor engaging part partially with respect to the said pile head installation part is arrange | positioned apart in the circumferential direction of the said 1st anchor member.
Thereby, when the head of the pile is inclined, the anchor engaging portion can be brought into a normal horizontal state with a plurality of jack portions while the pile head installing portion is installed in accordance with the pile. Thereby, an anchor bolt can be made into a regular vertical state reliably. As a result, it is possible to avoid tilting the pier. It is also possible to adjust the vertical position of the anchor engaging portion and thus the pier with a plurality of jack portions.

The second anchor member is preferably composed of an annular flat plate.
This makes it possible to simplify the configuration.

It is preferable that a support portion is provided at a lower end portion of the anchor bolt, and the second anchor member is supported so as to be placed on the support portion.
Since the inside of the pile above the lower end portion of the anchor bolt including the second anchor member and the support portion is filled with concrete, when an upward tensile stress acts on the anchor bolt, the concrete becomes the second anchor. By receiving an upward compressive force from the member, the lower end portion of the anchor bolt can be reliably restrained, and the anchor bolt can sufficiently resist the pulling force.

It is desirable that the support portion is a nut screwed to a lower end portion of the anchor bolt.
Thereby, a support part can be comprised easily.

Further, the present invention is a pier construction method,
Pile construction process to build a cylindrical pile in the ground,
An anchor installation step of disposing a lower end portion of the anchor bolt and a second anchor member provided at the lower end portion within the pile and installing a first anchor member engaged with the anchor bolt at the upper end portion of the pile. When,
A concrete placing step of filling concrete into the pile above the lower end of the anchor bolt including the second anchor member;
A steel pier is installed so that it is supported by the pile via the first anchor member and the upper end of the anchor bolt is joined when the filled concrete is not yet cured. Process,
It is characterized by performing.
As a result, the pier can be installed without waiting for the filled concrete to harden, and the construction period can be shortened.

It is desirable that the anchor bolt and the first and second anchor members are assembled in advance to form a unit, and the unit is installed on the pile. Thereby, the working efficiency of an anchor installation process can be improved.
The pile preferably includes PC steel. In this case, it is preferable that the upper end portion of the PC steel material is fixed to the first anchor member in a tension state after the anchor installation step.
A plurality of the PC steel materials are provided apart from each other in the circumferential direction of the pile, and the upper end portions of some of the plurality of PC steel materials are tensioned in the pile building process and fixed to the upper end surface of the pile. In addition, it is preferable that the upper end portion of the remaining PC steel material is tensioned and fixed to the first anchor member after the anchor installation step.

The anchor installation step includes a first anchor installation step of installing a first anchor member engaged with an anchor bolt at an upper end portion of the pile, a lower end portion of the anchor bolt, and a second anchor member provided at the lower end portion. The 2nd anchor installation process which arrange | positions inside the said pile.
As the first anchor member, a pile head installation part and an anchor engagement part that form separate bodies are prepared, and in the first anchor installation process, the pile head installation part is installed at the upper end of the pile, You may decide to install the said anchor engaging part while adjusting the relative position on the said pile head installation part while engaging with the said anchor bolt.
Thus, if there is an error in the construction of the pile, the pile head installation portion of the first anchor member can be installed in accordance with the position of the pile, while the anchor engagement portion can be installed at the regular position, and thus the anchor Bolts can be installed at regular positions. As a result, it is possible to avoid construction errors from occurring on the pier.

In the first anchor installation step, it is preferable that the anchor engagement portion is temporarily fixed to the pile head installation portion.
As a result, it is possible to prevent the anchor engaging portion and thus the anchor bolt from being displaced from the normal position in the concrete placing process and the pier setting process, and also during the curing period of the concrete, thereby ensuring the construction error of the pier. Can be avoided.

In the pier installation step, it is preferable to temporarily fix the pier to the pile head installation portion.
Thereby, during the curing period of the concrete, the pier can be prevented from deviating from a normal position, and construction errors of the pier can be more reliably avoided.

  According to the present invention, it is possible to provide a fixing structure capable of sufficiently exhibiting a required fixing strength with a simple configuration, and a significant cost reduction can be achieved. Also, since the load on the pier can be supported by the pile via the first anchor member, the pier can be installed without waiting for the concrete filled inside the pile to harden completely. Can be made more efficient.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a pier foundation structure in a bridge. A foundation pile 10 is embedded in the ground, and a steel pier 20 is erected above the foundation pile 10.

  As shown in FIG. 2, the steel pier 20 has a quadrangular prism shape, but is not limited thereto, and may have a cylindrical shape.

  As shown in FIG.1 and FIG.2, the foundation pile 10 is comprised by the PC well. The PC well 10 is configured by vertically stacking a plurality of cylindrical blocks 11 made of precast concrete. The shape of the block 11 is not limited to a cylinder, and may be another shape such as a square tube.

The inner diameter of the uppermost block 11A is larger than the inner diameter of the lower block 11, and it is between the inner peripheral surface of the uppermost block 11A and the inner peripheral surface of the second block 11 from the top. A step 11b is formed.
The uppermost block 11A may have the same inner diameter as the other blocks 11, and the step 11b may be eliminated.

As shown in FIG. 3, a plurality of vertical ducts 11 a are formed in each block 11 at intervals in the circumferential direction. A PC steel material 12 is inserted into each duct 11a. Prestress is applied to each block 11 by tensioning the PC steel material 12. A fixing fitting 13 for fixing the PC steel material 12 is embedded in the end surface of the block 11. The upper end portion of the PC steel material 12 is stopped by a nut 15.
Although not shown, the gap between the inner peripheral surface of the duct 11a of the block 11 and the PC steel material 12 is filled with a grout agent.

  In the PC well 10, the PC steel materials 12 of the blocks 11 adjacent in the vertical direction are connected in a straight line by a coupler 14. The lower end portion of the duct 11 a of the block 11 is expanded in diameter to accommodate the coupler 14 and the nut 15.

As shown in FIG. 1, the base portion (lower end portion) of the pier 20 is fixed to the upper end portion of the foundation pile made of the PC well 10 via the anchor structure 30. The anchor structure 30 is configured as follows.
As shown in FIG. 9, the anchor structure 30 is a unit mainly composed of an anchor bolt 31, a first anchor member 40, and a second anchor member 50. As shown in FIGS. 2 and 3, a plurality of anchor bolts 31 are arranged around the pier 20 at intervals. Each anchor bolt 31 is vertical and straddles the PC well 10 from the base of the pier 20. A base flange 21 and a base plate 22 are provided at the base of the pier 20 so as to make a pair in the vertical direction. The upper ends of the anchor bolts 31 are joined to the base flange 21 and the base plate 22 with nuts 23. As shown in FIG. 3, the anchor bolt 31 below the base plate 22 is inserted into the PC well 10.

As shown in FIG. 2, a first anchor member 40 is provided at the upper end portion of the foundation pile made of the PC well 10. As shown in FIGS. 3 and 4, the first anchor member 40 has a bottom 41 and a peripheral wall 42, and is annular as a whole. The bottom 41 is made of an annular flat steel plate. As shown in FIG. 4, a plurality of relatively small-diameter first holes 41 a and relatively large-diameter second holes 41 b are formed in a portion near the outer periphery of the bottom 41. The first hole 41 a is smaller than the nut 15 for fixing the PC steel material 12, and the second hole 41 b is larger than the nut 15. These first and second holes 41 a and 41 b are alternately arranged at intervals in the circumferential direction of the bottom portion 41.
A plurality of third holes 41c are formed in a portion near the inner periphery of the bottom portion 41 at intervals in the circumferential direction.

  As shown in FIGS. 2 and 3, the peripheral wall 42 is made of a cylindrical steel material having the same diameter as the outer diameter of the annular bottom 41. The lower end portion of the cylindrical peripheral wall 42 is joined to the outer peripheral portion of the annular bottom portion 41 by welding. A first anchor member main body 40 </ b> X is configured by the annular bottom portion 41 and the cylindrical peripheral wall 42.

  As shown in FIG. 4, vertical ribs 43 are provided on the first anchor member main body 40 </ b> X. A plurality of the vertical ribs 43 are arranged at intervals in the circumferential direction of the first anchor member 40. Each vertical rib 43 is formed of a rectangular flat steel plate and is oriented so as to be perpendicular to the radial direction of the first anchor member 40. The plurality of vertical ribs 43 are arranged radially in plan view as a whole. The lower end edge of the vertical rib 43 is joined to the upper surface of the bottom portion 41 by welding, and the outer end edge is joined to the inner peripheral surface of the peripheral wall 42 by welding. The heights of the upper end edges of the plurality of vertical ribs 43 are aligned so as to be located on the same horizontal plane. The upper end edge of these vertical ribs 43 and the upper end edge of the peripheral wall 42 are substantially flush.

  As shown in FIG. 3, the first anchor member 40 is placed on the upper surface of the uppermost block 11 </ b> A of the PC well 10. Upper end portions of the plurality of PC steel materials 12A of the uppermost block 11A are inserted into the first and second holes 41a and 41b of the first anchor member 40, respectively. A nut 15 is screwed into the upper end of the PC steel material 12A. The nut 15 </ b> A corresponding to the first hole 41 a is pressed against the upper surface of the bottom 41 of the first anchor member 40. Thereby, 12 A of PC steel materials penetrated by the 1st hole 41a and the 1st anchor member 40 are joined. The nut 15B corresponding to the second hole 41b is accommodated in the second hole 41b and pressed against the fixing bracket 13 of the uppermost block 11A.

  The outer diameter of the first anchor member 40 is approximately the same as the outer diameter of the PC well 10. Thereby, the outer peripheral surface of the first anchor member 40 is substantially flush with the outer peripheral surface of the PC well 10.

  On the other hand, the inner diameter of the first anchor member 40 is smaller than the inner diameter of the PC well 10 (not to mention the uppermost block 11A, but the inner diameter of the lower block 11). Accordingly, the inner end portion of the first anchor member 40 extends radially inward from the inner peripheral surface of the PC well 10. A third hole 41 c is provided in the radially inwardly extending portion of the first anchor member 40. An intermediate portion of the anchor bolt 31 is inserted into the third hole 41 c, and the anchor bolt 31 is joined to the first anchor member 40 with a nut 32. As a result, the anchor bolt 31 and the PC steel material 12 of the PC well 10 are connected via the first anchor member 40, and further, the steel pier 20 and the PC well 10 are connected.

  The inner diameter of the first anchor member 40 is smaller than the outer diameter of the base plate 22 of the pier 20. The first anchor member 40 is located below the base plate 22. The base plate 22 and thus the pier 20 are mounted on the upper end edge of the vertical rib 43 of the first anchor member 40.

As shown in FIG. 4, in the first anchor member 40, an annular portion between the outer periphery and the position corresponding to the inner periphery of the upper end surface of the PC well 10 is referred to as a pile head installation portion 48, and this pile head installation is performed. The annular portion radially inward from the portion 48 is referred to as an anchor joint portion 49 (anchor engaging portion). The pile head installation portion 48 and the anchor joint portion 49 of the first anchor member 40 are continuously connected.
A pile head installation section 48 is installed on the PC well 10. A first hole 41 a and a second hole 41 b are formed in the pile head installation portion 48. The upper end portion of the PC steel material 12A of the PC well 10 is fixed to the pile head installation portion 48 using these holes 41a and 41b.
The anchor joint portion 49 extends radially inward from the upper end surface of the PC well 10. A third hole 41 c is formed in the anchor joint portion 49. The anchor bolt 31 is inserted into the third hole 41c, and the anchor joint portion 49 and the anchor bolt 31 are joined.

  As shown in FIG. 3, the second anchor member 50 is disposed at a position slightly above the step 11 b inside the PC well 10. As shown in FIG. 5, the 2nd anchor member 50 is comprised with the cyclic | annular flat steel plate. A plurality of fourth holes 51 are formed in the second anchor member 50. The fourth holes 51 are arranged at intervals in the circumferential direction of the second anchor member 50. The lower end portion of the anchor bolt 31 is inserted into the fourth hole 51. A nut 33 (engagement support portion) is provided at the lower end portion of the anchor bolt 31, and the second anchor member 50 is placed (supported) on the nut 33 so as to be supported (engaged). Yes.

  As shown in FIG. 3, a steel plate-like bottom mold 60 is horizontally disposed in a portion below the second anchor member 50 inside the PC well 10. The bottom end of the anchor bolt 31 is joined to the bottom mold 60 by, for example, welding. The top concrete 70 is filled in place inside the PC well 10 between the mold 60 and the lower end of the pier 20. The bottom half of the anchor bolt 31, the first anchor member 40, and the second anchor member 50 are buried in the top concrete 70. The top concrete 70 is also filled inside each chamber of the first anchor member 40 partitioned by the vertical ribs 43.

The construction method of the foundation pile 10 and the pier 20 is demonstrated.
[Pile construction process]
First, the blocks 11 are sequentially driven to construct the PC well 10. As shown in FIG. 6, every time one block 11 is driven, the PC steel material 12 of the next block 11 is added in a straight line to the upper end portion of the PC steel material 12 of the driven block 11 via a coupler 14. While inserting the added PC steel material 12 into the duct 11a of the next block 11, the next block 11 is stacked. The PC steel material 12 of the newly stacked block 11 is tensioned by a prestress introduction device (not shown) to give prestress, and is fixed by the nut 15. A grout agent is filled between the strained PC steel 12 and the duct 11a.

  As shown in FIG. 7, a press-fitting device 80 is installed around the PC well 10. The press-fitting device 80 includes a ground anchor 81 driven into the ground, a plurality of (for example, three, only two shown in the figure) shafts 82 erected on the ground, and horizontally spanned between the shafts 82. The pressurizing frame 83 and a jack 84 that is moved up and down along the shaft 82 are provided. The pressure frame 83 is addressed to the upper surface of the block 11 via the protective ring 85.

  As shown in FIG. 8, the jack 84 of the press-fitting device 80 is driven, and the pressurizing frame 83 is pushed down. As a result, the plurality of stacked blocks 11, 11... Are press-fitted into the ground. At this time, the pressure input of a plurality of (for example, three) jacks 84 is adjusted while measuring the verticality with an inclinometer. Thereby, the perpendicularity of the laminated blocks 11, 11,... Can be ensured.

  The above operation is repeated for the number of stages of the block 11. For the uppermost block 11A, after the uppermost block 11A is added onto the second block 11 from above, a part of the plurality of PC steel materials 12A of the uppermost block 11A (for example, every other one in the circumferential direction). PC steel 12A) is tensioned and fixed with nut 15B. Thus, prestress can be applied to the uppermost block 11A to some extent before press-fitting. Then, press-fitting is performed by the press-fitting device 80. When press-fitting the uppermost block 11A further deeper, a dummy block (not shown) is placed on the uppermost block 11A to perform press-fitting operation. Thereby, as shown in FIG. 1, the PC well 10 is constructed in the ground.

[Anchor installation process]
Separately, as shown in FIG. 9, the anchor bolt 31, the first anchor member 40, the second anchor member 50, and the mold 60 are assembled to form a unit of the anchor structure 30. As shown by the arrow in FIG. 9, the unit of the anchor structure 30 is inserted into the PC well 10. Then, as shown in FIG. 10, the first anchor member 40 is placed on the upper end surface of the PC well 10. At this time, among the uppermost PC steel material 12A, the upper end portion of the unstrained PC steel material 12A is inserted into the first hole 41a, the upper end portion of the tensioned PC steel material 12A is inserted into the second hole 41b, and the nut 15B is inserted. It arrange | positions in the 2nd hole 41b. Next, a pre-stress introducing device is connected to the upper end portion of the non-tensioned PC steel material 12A, and the pre-stress is applied by tensioning the PC steel material 12A. A nut 15A is screwed onto the upper end of the PC steel material 12A, and the nut 15A is pressed against the upper surface of the bottom 41 of the first anchor member 40.
As a result, the anchor bolt 31 is connected to the PC steel material 12 of the PC well 10 via the first anchor member 40.
If the PC well 10 is vertical, the first anchor member 40 can be installed horizontally and the anchor bolt 31 can be installed vertically.

[Concrete placing process]
Next, as shown in FIG. 11, top concrete 70 is placed in the PC well 10 above the mold 60. As a result, the lower portion of the anchor bolt 31 and the second anchor member 50 are buried in the top concrete 70. Further, the bottom 41 and the vertical ribs 43 of the first anchor member 40 are buried in the top concrete 70. The top concrete 70 is driven up to the height of the peripheral wall 42 of the first anchor member 40 and the upper edge of the vertical rib 43.

[Bridge pier installation process]
Subsequently, installation work of the pier 20 is performed. That is, while lowering the pier 20, the upper end portion of the anchor bolt 31 is passed through the insertion hole 22 a of the base plate 22 of the pier 20 and further passed through the insertion hole 21 a of the base flange 21. Then, the base plate 22 is placed on the vertical ribs 43 of the first anchor member 40. At this time, the load of the pier 20 can be supported by the PC well 10 via the first anchor member 40. Therefore, there is no need to wait for the top concrete 70 to set completely. Thereby, the construction period can be shortened.
As described above, by ensuring the verticality of the PC well 10 when the PC well 10 is constructed, the first anchor member 40 can be leveled, and thus the pier 20 mounted thereon can be easily vertical. Can be.

According to the bridge having the fixing structure, the anchor bolt 31 and the PC steel material 12 are connected via the first anchor member 40, so that the force is surely transmitted from the pier 20 to the foundation pile 10. can do. When a force in the bending direction is applied to the pier 20, the compressive force can be reliably transmitted to the top slab concrete 70 and the PC well 10 via the first anchor member 40 on the compression side. On the pulling side, upward stress can be transmitted to the top concrete 70 via the anchor bolt 31, the nut 33, and the second anchor member 50 in order, and this becomes a fixing force so that the anchor bolt 31 can sufficiently withstand the pulling force. Can resist.
Thus, the anchor structure 30 can sufficiently exhibit the required fixing strength with a simple configuration. In particular, the second anchor member 50 at the lower part of the anchor structure 30 can be configured by simply placing a single flat plate on the nut 33 of the anchor bolt 31, and thus can be easily manufactured and greatly reduced in cost.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are given to the drawings and the description thereof will be omitted as appropriate for configurations overlapping with the above-described embodiments.
FIG. 12 shows a second embodiment of the present invention. In this embodiment, the pile head installation part 110 and the anchor joint part 120 (anchor engagement part) of the first anchor member 100 are separate from each other.

  As shown in FIGS. 12 and 13, the pile head installation portion 110 of the first anchor member 100 includes an upper plate portion 111, a bottom portion 112, a peripheral wall 113, and vertical ribs 114. The upper plate portion 111 and the bottom portion 112 are each made of an annular steel plate, and are arranged vertically in parallel with each other. A fixing metal fitting 150 is provided on the upper surface of the bottom portion 112. The peripheral wall 113 is made of a cylindrical steel material. The outer peripheral portion of the upper plate portion 111 is joined to the upper end portion of the peripheral wall 113 by welding, and the outer peripheral portion of the bottom portion 112 is joined to the lower end portion by welding. As shown in FIG. 12, the upper plate portion 111, the bottom portion 112, and the peripheral wall 113 constitute a pile head installation portion main body having a U-shaped cross section. As shown in FIG. 13, the plurality of vertical ribs 114 are arranged at intervals in the circumferential direction of the first anchor member 110. Each vertical rib 114 is formed of a rectangular flat steel plate and is oriented so as to be perpendicular to the radial direction of the first anchor member 110. The plurality of vertical ribs 114 are arranged radially in plan view as a whole. The upper end edge of the vertical rib 114 is joined to the upper plate portion 111 by welding, the lower end edge is joined to the bottom portion 112 by welding, and the outer end edge is joined to the inner peripheral surface of the peripheral wall 113 by welding.

  As shown in FIG. 12, the pile head installation part 110 is placed on the upper surface of the uppermost block 11 </ b> A of the foundation pile 10. The upper end portion of the PC steel material 12 </ b> A of the uppermost block 11 </ b> A is fixed to the fixing bracket 150 in the pile head installation portion 110.

  The outer diameter of the pile head installation part 110 is substantially the same as the outer diameter of the foundation pile 10. Thereby, the outer peripheral surface of the pile head installation part 110 is substantially flush with the outer peripheral surface of the foundation pile 10.

  As shown in FIG. 13, the anchor joint portion 120 of the first anchor member 100 is configured by an annular flat steel plate. The outer diameter of the anchor joint part 120 is smaller than the outer diameter of the pile head installation part 110 and larger than the inner diameter of the pile head installation part 110. The inner diameter of the anchor joint portion 120 is smaller than the inner diameter of the pile head installation portion 110.

  As shown in FIG. 12, the outer peripheral portion of the anchor joint 120 is placed on the upper plate portion 111 of the pile head installation portion 110. As shown in FIGS. 13 and 16, a plurality of jackup tap holes 122 are formed in the outer peripheral portion of the anchor joint portion 122 so as to be separated in the circumferential direction. A jack-up bolt 171 is screwed into each tap hole 122. By abutting the bolt 171 against the upper plate portion 111 of the pile head installation portion 110, the portion around the bolt 171 of the anchor joint portion 120 can be moved up and down with respect to the pile head installation portion 110. A jack portion 170 is constituted by the tap hole 122 and the jack up bolt 171.

  As shown in FIG. 12, a portion on the inner peripheral side of the anchor joint portion 120 extends from the pile head installation portion 110 inward in the radial direction. An anchor bolt insertion hole 121 is formed in the extending portion. As shown in FIG. 13, a plurality of anchor bolt insertion holes 121 are arranged apart in the circumferential direction of the anchor joint 120. As shown in FIG. 12, an intermediate portion of the anchor bolt 31 is inserted into each insertion hole 121. The anchor bolt 31 is connected and joined (engaged) to the anchor joint portion 120 by a pair of upper and lower nuts 32.

On the anchor joint 120, the base plate 22 of the pier 20 is mounted.
As shown in an imaginary line in FIG. 13 and FIG. 15, a plurality of temporary fixing overhang portions 24 projecting in the radial direction are provided on the outer peripheral portion of the pier base plate 22 apart in the circumferential direction.

  As shown in FIG. 13, the first anchor member 100 is provided with a plurality of temporary fixing arrangement portions 115 apart in the circumferential direction. The number of the temporary fixing arrangement portions 115 is twice the number of the temporary fixing protruding portions 24 of the pier 20. Every other temporary fixing arrangement portion 115 and the temporary fixing overhanging portion 24 of the pier 20 are arranged to face each other at the same angle.

Each temporary fixing placement portion 115 includes a plurality of temporary fixing insertion holes 115a formed through the upper plate portion 111 of the pile head installation portion 110, and a plurality of temporary fixing portions provided by welding or the like on the lower surface of the upper plate portion 111. And a locking nut 115b. The insertion holes 115 a of the temporary fixing arrangement portions 115 are arranged in two rows at equal intervals in the radial direction of the upper plate portion 111. These insertion holes 115 a are arranged over a range from the radial intermediate portion to the outer peripheral portion of the upper plate portion 111. A temporary fixing nut 115b is connected to the lower end of each insertion hole 115a in a straight line.
A female screw may be formed on the inner peripheral surface of the hole 115a, and the nut 115b may be omitted.

  Temporary fixing members 130 and 130X are arranged in each temporary fixing arrangement portion 115. These temporary fixing members 130, 130 x have a rectangular bottom plate 131 and a rib 132 provided on the upper surface of the bottom plate 131. The rib 132 extends in the longitudinal direction at the center in the width direction of the bottom plate 131. Insertion holes 131a are formed through both sides of the bottom plate 131 with the rib 132 interposed therebetween.

As shown in FIGS. 12 and 13, every other temporary fixing member 130 in the circumferential direction of the first anchor member 100 is disposed so as to straddle from the upper side of the pile head installation portion 110 to the upper surface of the anchor joint portion 120. ing. A spacer 140 having the same thickness as the anchor joint 120 is sandwiched between the temporary fixing member 130 and the upper plate portion 111. Bolts 133 are passed through the plurality of insertion holes 131 a of the temporary fixing member 130. These bolts 133 penetrate the spacer 140, are inserted into a part of the plurality of insertion holes 115a of the pile head installation part 110, and are screwed into the nuts 115b. Accordingly, the temporary fixing member 130 presses the anchor joint portion 120. Thereby, the anchor joint part 120 is temporarily fixed.
By selecting the hole 115 a through which the bolt 33 is inserted, the arrangement position of the temporary fixing member 130 can be adjusted in the radial direction of the pile head installation portion 110.

As shown in FIGS. 14 and 15, the remaining temporary fixing member 130 </ b> X is disposed at a position corresponding to the overhang portion 24 of the pier 20 so as to straddle the upper surface of the overhang portion 24 from above the pile head installation portion 110. Is arranged. Between the temporary fixing member 130 </ b> X and the upper plate portion 111, a spacer 141 having a total thickness of the anchor joint portion 120 and the overhang portion 24 is sandwiched. Bolts 133 are passed through the plurality of insertion holes 131a of the temporary fixing member 130X. These bolts 133 pass through the spacer 141, are inserted into some of the plurality of insertion holes 115a of the pile head installation portion 110, and are screwed into the nuts 115b. Accordingly, the temporary fixing member 130X presses the overhang portion 24. Thereby, the pier 20 is temporarily fixed.
By selecting the hole 115a through which the bolt 33 is inserted, the arrangement position of the temporary fixing member 130X can be adjusted in the radial direction of the pile head installation portion 110.

As shown in FIG. 12, in the second embodiment, the lower end portion of the anchor bolt 31 is located above the bottom mold 60.
The outer diameter of the bottom mold 60 is smaller than the inner diameter of the second block 11 of the foundation pile 10 by several tens of mm. The bottom mold 60 can be displaced with respect to the foundation pile 10 by this dimensional difference.

A pedestal 16 is provided on the inner peripheral surface of the second block 11. An outer peripheral portion of the bottom mold 60 is placed on and supported by the pedestal 16. The pedestal 16 is made of concrete integrated with the block 11, but may be made of a metal member separate from the block 11. This pedestal fitting may be retrofitted to the block 11 or may be inserted when the block 11 is manufactured.
In FIG. 12, reference numeral 71 denotes a vertical reinforcing bar embedded in the top concrete 70. (In the first embodiment, the vertical reinforcing bar 71 is not shown.)

  In the second embodiment, after the foundation pile 10 is constructed, the pile head installation portion 110 of the first anchor member 100 is installed on the upper surface of the foundation pile 10 while accurately aligning with the foundation pile 10. The upper end portion of the PC steel material 12 is fixed to the pile head installation portion 110.

  Separately, the anchor bolt 31 is joined to the anchor joint 120. A second anchor member 50 is attached to the lower end portion of the anchor bolt 31. Thereby, the anchor structure 160 which includes the anchor joint part 120, the anchor bolt 31, and the second anchor member 50 and does not include the pile head installation part 110 is constructed.

  The anchor bolt 31 of the anchor structure 160 is inserted into the foundation pile 10 and the anchor joint portion 120 is placed on the pile head installation portion 110. At this point, the anchor structure 160 is separated from the foundation pile 10 and is adjustable in relative position. Therefore, for example, as shown by the phantom line in FIG. 12, even if the foundation pile 10 is installed slightly shifted in the horizontal direction from the normal position, the anchor structure 160 is not limited regardless of the position of the foundation pile 10. Can be placed in position. Of course, even if the foundation pile 10 is deviated from the normal angle in the circumferential direction, the anchor structure 160 can be arranged at a normal angle.

  Subsequently, the temporary fixing member 130 is arranged on every other temporary fixing placement portion 115 of the pile head installation portion 110 so as to straddle the anchor joint portion 120 from the pile head installation portion 110 via the spacer 140. At this time, the radial position of the temporary fixing member 130 is adjusted in accordance with the relative position of the anchor joint portion 120 and the pile head installation portion 110, and the hole 131 a of the temporary fixing member 130 is any hole of the temporary fixing arrangement portion 115. 115a. Then, the anchor joint 120 is sandwiched between the temporary fixing member 130 and the pile head installation part 110 by tightening the bolt 133. The temporary fixing member 130 is installed at a plurality of locations in the circumferential direction of the anchor joint 120. As a result, the anchor joint 120 and thus the anchor structure 160 can be temporarily fixed.

  Thereafter, a concrete 70 placing step is performed. The bottom mold 60 is installed on the pedestal 16 prior to installation of the anchor structure 160. Concrete 70 is placed above the bottom mold 60. Since the anchor structure 160 is temporarily fixed, it is possible to prevent the anchor structure 160 from deviating from the normal position due to concrete placing pressure or the like.

  After the concrete 70 is placed, the pier 20 is installed before it is hardened. Since the anchor bolt 31 is disposed at the regular position, the pier 20 can be reliably disposed at the regular position (horizontal and circumferential positions) regardless of the construction error of the pile 10. .

  Subsequently, the temporary fixing member 130X is arranged on the remaining temporary fixing arrangement portion 115 of the pile head installation portion 110 so as to straddle the overhanging portion 24 of the pier base plate 22 from the pile head installation portion 110 via the spacer 141. At this time, the radial position of the temporary fixing member 130X is adjusted according to the relative position between the pile head installation part 110 and the overhanging part 24, and the hole 131a of the temporary fixing member 130X is any hole of the temporary fixing arrangement part 115. 115a. Then, the bolt 133 is tightened, and the projecting portion 24 and the anchor joint portion 120 are sandwiched between the temporary fixing member 130X and the pile head installation portion 110. Accordingly, the pier 20 can be temporarily fixed, and the pier 20 can be prevented from being displaced from the normal position during the curing period of the concrete 70. Then, the concrete 70 is hardened, so that the pier 20 is firmly fixed at a normal position.

Up to this point, it is assumed that the pile 10 is displaced from the normal position in the horizontal direction or the circumferential direction while maintaining the vertical degree. However, as shown in FIG. 16, the pile 10 is inclined and installed. Is also envisaged. In addition, the inclination of the pile 10 of the figure is exaggerated.
In this case, the pile head installation part 110 is installed in accordance with the pile 10, while the jackup bolts 171 are screwed into the jackup tap holes 122 that are arranged apart from each other in the circumferential direction of the anchor joint part 120. The bolt 171 is abutted against the upper plate part 111 of the pile head installation part 110. By adjusting the screwing amounts of these bolts 171 to each other, the anchor joint portion 120 can be leveled even if the pile head installation portion 110 is inclined. As a result, the anchor bolt 31 can be made vertical. As a result, the pier 20 can be constructed vertically regardless of the vertical accuracy of the pile 10.
A gap is formed between the circumferential position on the side inclined downward in the pile head installation part 110 and the anchor joint part 120. The spacer 142 is bitten in this gap.
Also in the corresponding construction method when the pile is inclined, the anchor joint portion 120 and the pier 20 are temporarily fixed by the temporary fixing members 130 and 130X at a position away from the jack portion 170 in the circumferential direction.

  Even when the pile 10 is installed vertically, when the jack-up bolts 171 are screwed into the respective tap holes 122 and the jack-up amounts are made to coincide with each other, the vertical position of the anchor joint 122 and thus the pier 20 is adjusted. be able to.

FIG. 17 shows a third embodiment according to a modification of the second embodiment.
In 3rd Embodiment, the engagement form of the anchor bolt 31 of the anchor structure 160 and the 1st, 2nd anchor members 100 and 50 differs from 2nd Embodiment. More specifically, the intermediate portion of the anchor bolt 31 is only inserted through the anchor bolt insertion hole 121 of the anchor engaging portion 120 of the first anchor member 100, and the anchor engaging portion 120 by the nut 32 (FIG. 12). It is not joined to. On the other hand, the lower end portion of the anchor bolt 31 is passed through the insertion hole 51 of the second anchor member 50 and is joined to the second anchor member 50 by a pair of upper and lower nuts 33, 33.

The anchor engaging portion 120 and the second anchor member 50 are connected by a brace 161 and maintain a predetermined interval in the vertical direction. Therefore, the anchor engaging portion 120 when the anchor structure 160 is built is supported by the second anchor member 50 via the brace 161. Both end portions of the brace 161 are joined to the anchor engaging portion 120 or the second anchor member 50 by welding, respectively, but are not limited to welding, and may be bolt joined.
The brace 161 is also provided in the anchor structure 160 of the second embodiment (FIGS. 12 to 16), but the illustration thereof is omitted.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the present invention can be applied not only to the connection between the base of the bridge pier and the foundation but also to the connection of a steel structure and a concrete structure, for example, in a bridge superstructure.
Installation work of the pier 20 may be performed when the top slab concrete 70 is hardened.
The engagement between the anchor bolt 31 and the anchor engaging portions 49 and 120 is not limited to the insertion into the through holes 41c and 121 and the joining by the nut 32. For example, wire bundles, hooking by a hook, pinching by a pinching member, etc. You may decide to.
The engagement between the anchor bolt 31 and the second anchor member 50 is not limited to the support by only the lower nut 33 or the joining by the pair of upper and lower nuts 33, 33, and for example, by wire bundle binding, hooking by a hook, or pinching member You may decide by pinching.

In the first embodiment, the planar view shape of the outer edge and the inner edge of the first anchor member 40 is not limited to a circle, and may be a polygon or other shapes. The outer edge shape and the inner edge shape are different from each other. May be.
In 1st Embodiment, the 3rd hole (anchor bolt insertion hole) 41c is made into a diameter hole larger than the anchor bolt 31, and the anchor bolt 31 comes to be joined to a pile head installation part so that relative position adjustment is possible. It may be.

In the 1st anchor member 100 of the separate structure of 2nd, 3rd embodiment, the outer diameter of the anchor engaging part 120 may be the same as the outer diameter of the pile head installation part 110, and the pile head installation part 110 It may be larger than the outer diameter.
The plan view shape of the outer edge and inner edge of the pile head installation part 110 and the outer edge and inner edge of the anchor engaging part 120 is not limited to a circle, but may be a polygon or other shapes. The shapes may be different from each other.
The anchor engaging portion 120 may not have an annular shape with a hole in the center, but may have a plate shape without a hole in the center or a plate shape with a plurality of holes.
Temporary fixing between the anchor engaging portion 120 and the pile head installing portion 110 may be performed by welding.
A fool hole is provided in one of the anchor engagement portion 120 and the pile head installation portion 110, a plate is directed to the fool hole, and the plate and the other of the anchor engagement portion 120 or the pile head installation portion 110 are bolted. By doing so, you may decide to temporarily fix the anchor engaging part 120 and the pile head installation part 110. FIG.
The temporary fixing members 130 and 130X may be adjusted in the radial direction of the pile head installation portion 110 by making the bolt insertion holes 131a of the temporary fixing members 130 and 130X into a long hole shape.

You may combine a part of structure mutually about 1st-3rd embodiment. For example, also in the first embodiment, the first anchor member 40 may be provided with an upper plate portion. You may decide to engage an anchor bolt with this upper board part.
Also in the first embodiment, the bottom mold 60 may be separated from the anchor bolt 31 and supported by the base 16.
Also in the first embodiment, in the pier installation step, the pier 20 may be temporarily fixed to the pile head installation unit 110 and the concrete 70 may wait for hardening.

It is a side view which shows the outline of the pier base fixing structure containing the anchor structure which concerns on 1st Embodiment of this invention. It is a perspective view of the above-mentioned pier base fixing structure. It is a side view of the said pier base fixing structure. It is a top view of the 1st anchor member of the said anchor structure. It is a top view of the 2nd anchor member of the above-mentioned anchor structure. It is the side view of the process of showing the construction procedure of the said pier base fixing structure, and adding the block of PC well. It is a side view of the state which set the press injection apparatus for the block of the said PC well. It is a side view of the process of press-fitting the block of the PC well into the ground with the press-fitting device. It is a side view of the process of installing the unit of the anchor structure above the PC well after the construction of the PC well. It is a side view of the state which installed the unit of the said anchor structure in the upper part of PC well. It is a side view of the process of installing a bridge pier after placing top plate concrete in the inside of the PC well. It is a longitudinal cross-sectional view which shows the outline of the pier base fixing structure concerning 2nd Embodiment of this invention along the XII-XII line | wire of FIG. It is a top view which shows the 1st anchor member of the said 2nd Embodiment in a partial cross section. It is a longitudinal cross-sectional view which shows the pier base fixing structure of the said 2nd Embodiment along the XIV-XIV line | wire of FIG. It is a top view of a part of the pier base fixing structure of the second embodiment. It is a longitudinal cross-sectional view which shows the pier base fixing structure when the foundation pile inclines in the said 2nd Embodiment along the XVI-XVI line of FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment which concerns on the modification of 2nd Embodiment.

Explanation of symbols

10 PC well (foundation pile)
11 Block 11A Uppermost block 11a Duct 11b Step 12 PC steel 12A Uppermost PC steel 13 Fixing bracket 14 Coupler 15 PC steel fixing nut 15A Uppermost PC steel fixing nut 15B Uppermost PC steel fixing nut 16 Formwork base 20 Pier 21 Base flange 21a Insertion hole 22 Base plate (base of bridge pier)
22a Insertion hole 23 Nut 24 Temporary fixing overhang 30 Anchor structure 31 Anchor bolt 32 Nut (joining member with first anchor member)
33 Nut (support or joint for the second anchor member)
40 First anchor member 40X First anchor member main body 41 Bottom 41a First hole (PC steel material insertion hole)
41b 2nd hole (nut insertion hole)
41c 3rd hole (anchor bolt insertion hole)
42 Peripheral wall 43 Vertical rib 48 Pile head installation part 49 Anchor joint part (anchor engagement part)
50 Second anchor member 51 Fourth hole (anchor bolt insertion hole)
60 Bottom formwork 70 Top plate concrete (cast-in-place concrete)
71 Vertical rebar 80 Press-fitting device 81 Ground anchor 82 Shaft 83 Pressure frame 84 Jack 85 Protective ring 100 First anchor member 110 Pile head installation part 111 Upper plate part 112 Bottom part 113 Peripheral wall 114 Vertical rib 115 Temporary fixing arrangement part 115a For temporary fixing Insertion hole 115b Temporary fastening nut 120 Anchor joint, anchor engagement part 121 Anchor bolt insertion hole 122 Jack-up tap hole 130 Temporary fastening member 131 Bottom plate 131a Insertion hole 132 Rib 133 Temporary fastening bolt 140 Spacer 141 Spacer 142 Spacer 150 Fixing Metal fitting 160 Anchor structure 161 Brace 170 Jack part 171 Jack up bolt

Claims (16)

It is a structure that anchors a steel pier to a pile made of cylindrical precast concrete containing PC steel,
Anchor bolts whose upper end is joined to the pier and whose lower end is inserted into the pile,
An annular pile head installation portion installed at the upper end of the pile, and an anchor engagement portion that extends radially inward from the pile and is engaged with an intermediate portion of the anchor bolt. A first anchor member comprising:
A second anchor member disposed inside the pile and engaged with a lower end of the anchor bolt;
The pier anchoring structure is characterized in that concrete is filled in the pile above the depth where at least the second anchor member is buried.   The pier fixing structure according to claim 1, wherein a PC steel material of the pile is joined to a pile head installation portion of the first anchor member.   The pile head installation portion of the first anchor member has an annular bottom portion, a peripheral wall provided on the outer periphery of the bottom portion, and a plurality of vertical ribs erected at intervals in the circumferential direction of the bottom portion. The pier anchoring structure according to claim 1, wherein the pier anchoring structure is provided.   The pier fixing structure according to any one of claims 1 to 3, wherein a pile head installation portion and an anchor engagement portion of the first anchor member are integrally connected.   The anchor engaging portion of the first anchor member can be installed separately from the pile head installation portion so as to be capable of adjusting a relative position on the pile head installation portion. The pier anchor structure according to any one of 3 above.   The pier anchoring structure according to claim 5, wherein the anchor engaging portion has an annular shape having an outer diameter larger than an inner diameter of the pile head installation portion and a smaller inner diameter.   The pile head installation part is provided with a plurality of temporary fixing arrangement parts arranged in the circumferential direction so as to be arranged so that the temporary fixing members for the anchor engaging parts can be adjusted in the radial direction. The pier anchor structure according to 5 or 6. The base of the pier is installed on the anchor engaging portion,
The pier fixing structure according to claim 7, wherein at least a part of the plurality of temporary fixing members arranged in the plurality of temporary fixing arrangement parts can temporarily fix the base portion of the pier.   The jack part which can raise / lower the said anchor engaging part partially with respect to the said pile head installation part is arrange | positioned in multiple numbers away in the circumferential direction of the said 1st anchor member, The Claim 5-8 characterized by the above-mentioned. The pier anchor structure according to any one of the above.   The pier anchoring device according to any one of claims 1 to 9, wherein the second anchor member is formed of an annular flat plate.   The support part is provided in the lower end part of the said anchor bolt, The said 2nd anchor member is supported so that it may be mounted on the said support part, The any one of Claims 1-10 characterized by the above-mentioned. The pier anchor structure described in 2.   The pier fixing structure according to claim 11, wherein the support portion is a nut screwed into a lower end portion of the anchor bolt. Pile construction process to build a cylindrical pile in the ground,
An anchor installation step of disposing a lower end portion of the anchor bolt and a second anchor member provided at the lower end portion within the pile and installing a first anchor member engaged with the anchor bolt at the upper end portion of the pile. When,
A concrete placing step of filling concrete into the pile above the lower end of the anchor bolt including the second anchor member;
A steel pier is installed so that it is supported by the pile via the first anchor member and the upper end of the anchor bolt is joined when the filled concrete is not yet cured. Process,
The pier construction method characterized by performing. As the first anchor member, a pile head installation portion and an anchor engagement portion that are separate from each other are prepared,
In the anchor installation step, the pile head installation portion is installed at the upper end portion of the pile, while the anchor engagement portion is engaged with the anchor bolt and the relative position is adjusted on the pile head installation portion. The pier construction method according to claim 13, wherein the pier construction method is installed.   The pier construction method according to claim 14, wherein, in the anchor installation step, the anchor engagement portion is temporarily fixed to the pile head installation portion.   The said pier installation process WHEREIN: The said pier is temporarily fixed with respect to the said pile head installation part, The pier construction method in any one of Claims 13-15 characterized by the above-mentioned.

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