JP2009019360A - Structure and method for jointing bridge pier and footing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently heighten pullout strength and flexural strength to centrifugal distortion at reasonable cost. <P>SOLUTION: In a structure 1 for joining bridge piers and a footing, bearing plates 21 are mounted to the inner surface of a steel pipe 2 in such a way as to be buried in a reinforced concrete body 8 formed in the steel pipe 2, and deformed reinforcing bars 6 are inserted in through holes 22 formed in at bearing plates. Since an approximately conical compressive strut 23 centering on the axis of member of the deformed reinforcing bars 6 is therefore formed between the deformed reinforcing bars 6 arranged in a pullout cross section and the bearing plates 21 when forced centrifugal deformation in generated in the steel pipe 2 due to a horizontal force acting on a top of the bridge pier 3, or when a large pullout force acts on the steel pipe 2, it is possible to substantially improve the pullout strength and flexural strength of a joint parts with the footing 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a joining structure and method of a pier and a footing used when joining a lower end of a steel pier to an RC footing.

  When joining the lower end of a steel pier to the foundation, a steel frame called an anchor frame is manufactured in advance, and then embedded in a footing, which is a reinforced concrete foundation, and then anchor bolts extending from the anchor frame are used. A method of bolting the lower end of a steel pier to an anchor frame has been widely used.

  Recently, in addition to such a method, a steel pipe with a large diameter called a socket steel pipe is installed on the foundation constructed in the ground, and then the lower end of the steel pier is inserted into the socket steel pipe, and then the steel pier A method of integrating the lower end of the steel pier, the socket steel pipe and the foundation by filling concrete between the outer surface and the inner surface of the socket steel pipe is also known, and according to such a method, rapid construction is possible. Therefore, it is possible to proceed with construction in a short construction period in a place with a lot of traffic.

  On the other hand, the joining method using an anchor frame is inherently expensive to produce an anchor frame. Therefore, when the size of a bridge is increased, the production cost is increased due to the increase in the size of the anchor frame and the strengthening of steel. In addition, the so-called double pipe construction method using the socket steel pipe inevitably increases the construction cost because the steel pipe is used twice.

JP-A-9-13320 JP-A-9-209308

  Under such circumstances, a joint construction method capable of reducing costs has been researched and developed. For example, a rib is provided on the inner surface of a steel pipe constituting a pier and a reinforcing bar is arranged at a position facing the rib, and in this state, A construction method (Patent Documents 1 and 2) in which concrete is placed on the surface has been developed.

  According to such a conventional construction method, the concrete filled in the steel pipe and the reinforcing bars embedded in the concrete form a reinforced concrete body in the steel pipe, and the forced rotation due to the pulling load received from the steel pipe and the horizontal displacement of the pier head Resist deformation.

  Therefore, not only the anchor frame but also the steel pier can be firmly joined to the footing, and a concrete restraining effect by the steel pipe can be expected. In addition, the construction method is more advantageous than RC piers that require formwork and demolding work when placing concrete.

  However, in order to arrange the reinforcing bars so as to face the ribs on the inner surface of the steel pipe on the relationship that a predetermined concrete covering thickness must be secured around the reinforcing bars, the reinforcing bars are arranged by the protruding portion of the ribs. It must be retracted inside the steel pipe.

  Here, the load transmission between the ribs and the reinforcing bars is performed via the compression struts formed between the ribs and the reinforcing bars, and the shear resistance of the concrete itself. Load transmission via struts cannot be expected to be much, and the concrete shear resistance is still limited due to the physical properties of concrete.

  For this reason, there has been a problem that the pullout strength of the reinforced concrete body and the bending strength against rotational deformation cannot be sufficiently ensured.

  The present invention has been made in view of the above-described circumstances, and provides a structure and method for joining a pier and a footing that can sufficiently increase the pulling strength and the bending strength against rotational deformation at a reasonable cost. With the goal.

  In order to achieve the above object, the joining structure of the pier and the footing according to the present invention has a predetermined gap formed between the footing formed of reinforced concrete and the upper surface of the footing as described in claim 1. The steel pipe disposed in the vertical position above the footing, the steel pipe joining rebar with one end embedded in the footing, and the other end of the steel pipe joining rebar filled in the steel pipe are embedded. A reinforced concrete body made of concrete and a bearing member attached to the inner surface of the steel pipe so as to be embedded in the reinforced concrete body, and the bearing member is formed so as to surround the steel pipe joining reinforcement By doing so, a substantially conical compression strut centering on the material axis of the steel pipe joining rebar is formed.

  Further, in the joining structure between the pier and the footing according to the present invention, the supporting member has a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe, and an insertion hole is formed in the vicinity of the width center. In addition, the steel pipe jointing reinforcing bar is inserted into the insertion hole.

  Further, in the joining structure of the bridge pier and the footing according to the present invention, the bearing member has a predetermined width along a direction from the inner surface of the steel pipe toward the center of the steel pipe, and a notch is formed in the steel pipe center side edge. In addition to the formed pressure bearing plate having an annular, rectangular or polygonal frame shape, the steel pipe joining rebar is disposed in the notch.

  Further, as described in claim 4, the method for joining the pier and the footing according to the present invention is the method for joining the pier and the footing for joining the pier composed of the steel pipe to the footing formed of reinforced concrete.

  The steel pipe joining rebar is formed so that one end of the steel pipe joining rebar is embedded in the footing, and a predetermined gap is formed between the lower end of the steel pipe and the upper surface of the footing. The steel pipe is positioned above the footing in a vertical posture so that the other end of the steel pipe is disposed in the steel pipe, the gap is closed with a predetermined formwork material, and the other end of the steel pipe joining rebar is embedded. The steel pipe is filled with concrete to form a reinforced concrete body in the steel pipe, and a supporting member is attached to the inner surface of the steel pipe so as to be embedded in the reinforced concrete body, and the steel pipe joining By forming the bearing member so as to surround the reinforcing steel bar, a substantially conical compression strut centering on the material axis of the steel pipe joining reinforcing bar is formed. Than is.

  Further, in the joining method of the pier and the footing according to the present invention, the supporting member has a predetermined width along a direction from the inner surface of the steel pipe toward the center of the steel pipe, and an insertion hole is formed in the vicinity of the width center. In addition, the steel pipe jointing reinforcing bar is inserted into the insertion hole.

  Further, in the method for joining the pier and the footing according to the present invention, the bearing member has a predetermined width along a direction from the inner surface of the steel pipe toward the center of the steel pipe, and a notch is formed in the steel pipe center side edge. In addition to the formed pressure bearing plate having an annular, rectangular or polygonal frame shape, the steel pipe joining rebar is disposed in the notch.

  The method for joining the pier and the footing according to the present invention is to form the mold material so that the vertical load of the steel pipe can be temporarily received, and after the concrete filled in the steel pipe is hardened, The material is removed.

  As a result of accumulating research and development, the present applicant attached a support member to the inner surface of the steel pipe so as to be embedded in the reinforced concrete body formed in the steel pipe, and for steel pipe joining. By forming the bearing member so as to surround the reinforcing bar, a novel invention has been made in which a substantially conical compression strut centering on the material axis of the reinforcing rod for steel pipe joining is formed. .

  In this way, the vertical component resultant force of the compression strut formed in a substantially conical shape becomes much larger than before, and when a pulling load acts on the steel pipe from above the pier, or due to a horizontal force acting on the pier top When subjected to forced rotational deformation from a steel pipe, it becomes possible to resist pull-out load and forced rotational deformation with a larger bearing pressure reaction force in the tensile cross section of the reinforced concrete body.

  On the other hand, since the resultant horizontal component force of the compression strut formed in a substantially conical shape is almost canceled out, the force that the concrete tends to expand in the lateral direction is significantly smaller than in the conventional case, and therefore, the restraining force of the steel pipe is reduced. Reliable adhesion of reinforcing bars is possible.

  Here, in the prior art in which ribs are provided on the inner surface of the steel pipe and the reinforcing bars are spaced apart from the ribs by the concrete covering thickness, the compression struts formed between the reinforcing bars and the ribs are obliquely downward from the reinforcing bars toward the ribs. Therefore, although depending on the size of the restraint action by the steel pipe and the shape of the steel pipe, the concrete expands in the lateral direction due to the horizontal component stress of the compression strut and the bond strength of the ribs is lowered, which is not preferable.

  In particular, in a square steel pipe having a smaller restraining force than a circular steel pipe having a relatively large restraining force for filling concrete, a decrease in rib adhesion strength becomes a problem.

  However, in the present invention, as described above, it is possible to resist the drawing load and forced rotation deformation without depending on the restraining force of the steel pipe, so that it can be applied to a steel pipe having any cross-sectional shape. In particular, when the present invention is applied to a rectangular steel pipe in which the rib adhesion strength tends to decrease, the effect is remarkable.

  As described above, the steel pipe targeted by the present invention can have any cross-sectional shape, and for example, a cross-sectional shape such as a circle, a square, or a polygon can be considered. For example, when a bridge is constructed in a mountainous area, the pier may become high, and in that case, the steel pipe is added by welding or the like.

  When the pier is composed of a plurality of steel pipes, the steel pipe of the present invention can be composed of a single steel pipe, or can be composed of a plurality of steel pipes. In addition to the lower steel pipe, a supporting member can be provided on the second and third steel pipes.

  In addition, although the steel pipe which comprises a pier is often called a steel shell, in this invention, it shall call a steel pipe as a concept also including a steel shell for convenience.

  The footing is made of reinforced concrete and generally accompanied by a pile, but in the present invention, the foundation structure is constituted only by the footing or it is joined to the pile and its head. It does not matter whether the foundation structure is composed of footing.

  The steel pipe joining rebar is one in which one end is embedded in the footing and the other end is embedded in the concrete filled in the steel pipe, and can be composed of a deformed reinforcing bar, for example.

  The bearing member has a compression strut in a substantially conical region around the material axis of the steel pipe joining rebar due to the bearing reaction force generated in the bearing member and the tensile adhesion stress generated around the steel pipe joining rebar. As long as it is configured to occur, the configuration is arbitrary.

  Here, the compression strut generally means a bundle of compressive stress regions formed in the reinforced concrete member when a predetermined external force is applied to the reinforced concrete member. In the present specification, it particularly refers to a compressive stress region formed in a bundle between the bearing member attached to the inner surface of the steel pipe and the reinforcing bar.

  In order for the compression strut to be formed in a substantially conical shape centered on the material axis of the steel pipe joining rebar, it is necessary that the bearing member be disposed so as to surround the steel pipe joining rebar. The term “conical shape” does not mean only a cone having a substantially circular bottom surface, but also includes a cone shape having a fan-shaped bottom surface with an opening angle of about 180 degrees or more. Even in such a case, it is possible to secure a sufficiently large bearing area as compared with the conventional case. In the same sense, the structure of the bearing member so as to surround the steel pipe joining rebar does not mean a complete envelopment, but a bearing area to the extent that a compression strut having a half cone or more is formed is secured. It is sufficient to surround the steel pipe joining rebars by about 180 degrees or more.

  Specific examples of the supporting member include, for example, an annular, rectangular frame, or polygonal frame-shaped support having a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe and an insertion hole formed in the vicinity of the width center. A structure in which the supporting member is configured by the pressure plate and a steel pipe joining rebar is inserted through the insertion hole is conceivable.

  Further, the bearing member is supported by an annular, rectangular frame-shaped or polygonal frame-shaped bearing plate having a predetermined width along the direction from the inner surface of the steel tube toward the center of the steel tube and having a notch formed at the edge on the steel tube center side. A configuration in which a steel pipe joining rebar is arranged in the notch is conceivable.

  In order to construct a joint structure between a pier and a footing according to the present invention, first, the footing is formed so that one end of a steel pipe joining rebar is embedded in the footing, and then the lower end of the steel pipe and the upper surface of the footing The steel pipe is positioned above the footing in a vertical posture so that a predetermined gap is formed between the steel pipe and the other end of the steel pipe joining rebar is disposed in the steel pipe. The steel pipe may be filled with concrete so that the other end of the steel pipe joining rebar is buried and sealed with the frame material.

  Here, if the formwork material is configured so that the vertical load of the steel pipe can be temporarily received, it is possible to easily perform the temporary reception of the steel pipe before the concrete filling and placing. In such a case, the mold material is removed after the concrete filled in the steel pipe is cured.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a structure and a method for joining a pier and footing according to the present invention will be described below with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.

  FIG. 1 is a view showing a joint structure between a pier and a footing according to the present embodiment. As can be seen from the figure, the pier and footing joint structure 1 according to the present embodiment is formed by joining a pier 3 formed of a steel pipe 2 to a footing 4 formed of reinforced concrete.

  Between the lower end of the steel pipe 2 and the upper surface of the footing 4, the steel pipe 2 is arranged above the footing 4 in a vertical posture so that a gap h is formed.

  One end of a deformed rebar 6 as a steel pipe joining rebar is embedded in the footing 4, and the other end of the deformed rebar is embedded in a concrete 7 filled in the steel pipe 2.

  The deformed reinforcing bar 6 forms a reinforced concrete body 8 together with the concrete 7 filled in the steel pipe 2, and the reinforced concrete body 8 resists the pulling force when a pulling force acts on the pier 3 as will be described later. When the horizontal force acts on the head of the bridge pier 3, it acts to bend the rotational deformation of the steel pipe 2 due to the horizontal force and transmit the horizontal force to the footing 4.

Here, a bearing plate 21 as a bearing member is attached to the inner surface of the steel pipe 2 so as to be embedded in the reinforced concrete body 8.
FIG. 2 shows the bearing plate 21 in an overall perspective view and a plan view.
As can be seen from the figure, the bearing plate 21 has a rectangular frame shape with a rectangular opening 23 formed in the center, has a width W along the direction from the inner surface of the steel pipe 2 to the center of the steel pipe 2, and the vicinity of the width center. A plurality of insertion holes 22 are formed, and the deformed reinforcing bars 6 are respectively inserted into the insertion holes, so that the periphery of the deformed reinforcing bars is surrounded by a plate material constituting the bearing plate 21.

  The bearing plate 21 may be appropriately set with respect to the installation pitch in the height direction and the number of installation stages depending on the magnitude of the pulling force acting on the steel pipe 2 and the magnitude of forced rotational deformation received from the steel pipe 2.

  The insertion hole 22 is formed to have an inner diameter larger than the outer diameter of the deformed reinforcing bar so that the deformed reinforcing bar 6 can be easily inserted. However, the inner diameter is brought close to the outer diameter of the deformed reinforcing bar 6 within a range where there is no problem in construction. This is desirable for increasing the bearing area.

  The deformed reinforcing bars 6 are each configured in a straight bar shape, and as shown in FIG. 1 (b), if the steel pipe 2 is a square steel pipe, it may be arranged in a rectangular shape at a predetermined pitch, and if it is a round steel pipe, it will be circular. Just place it.

  In order to construct the joint structure 1 between the pier and the footing according to the present embodiment, first, as shown in FIG. 3, after the pile 11 is driven into the ground (not shown), the footing 4 is attached to the head of the pile. In the foundation work, the footing is formed so that one end of the deformed reinforcing bar 6 is embedded in the footing 4.

  The deformed reinforcing bar 6 may be appropriately embedded in the footing 4 so that it can be inserted into the insertion hole 22 of the bearing plate 21 attached to the inner surface of the steel pipe 2 erected in the subsequent process.

  Next, as shown in FIG. 4, the mold material 12 is placed on the upper surface of the footing 4. The formwork material 12 is composed of a rectangular frame having an L-shaped cross section. By placing the lower end of the steel pipe 2 on the shoulder 13 formed on the inner peripheral side, the lower end of the steel pipe and the upper surface of the footing 4 are formed. The gap h is closed and the load on the steel pipe 2 can be temporarily received.

  The formwork material 12 is positioned on the upper surface of the footing 4 so that the deformed rebar 6 can be inserted into the insertion hole 22 of the bearing plate 21 attached to the inner surface of the steel pipe 2 erected in the next step.

  Next, the steel pipe 2 is suspended above the footing 4 in a vertical posture so that the lower end of the steel pipe 2 is placed on the shoulder 13 of the mold member 12 while the deformed reinforcing bar 6 is inserted into the insertion hole 22 of the bearing plate 21. The steel pipe 2 is temporarily received by the formwork material 12.

  Next, concrete 7 is cast and filled in the steel pipe 2 to a height at which the deformed reinforcing bar 6 is embedded.

  When the cast concrete 7 is hardened, the formwork 12 is finally removed.

  In the pier and footing joint structure 1 constructed as described above, as shown in FIG. 5, a compressive load acts from above the pier 3, and the compressive load is applied to a bearing plate attached to the inner surface of the steel pipe 2. It is transmitted to the reinforced concrete body 8 via 21 and further transmitted to the footing 4 to support the compressive load.

  Further, assuming that a horizontal force acts on the head of the pier 3 in the right direction, the steel pipe 2 tries to rotate clockwise by the horizontal force.

Therefore, the horizontal force P having the distributed shape shown in FIG. 6 (a) acts on the side surface of the reinforced concrete body 8 from the steel pipe 2, and the tensile force T from the deformed reinforcing bar 6 located on the left side is located on the left bottom surface and on the right side. The compressive force C ₁ from the deformed rebar 6 and the compressive force C ₂ from the right upper surface of the footing 4 act on the right bottom surface, and the horizontal reaction force H from the footing 4 acts on the bottom surface. The RC member made of 6 and filled concrete 7 resists these forces by bending shear.

  Here, in the left tensile cross section of the reinforced concrete body 8, as shown in FIG. 5B, tensile adhesion stress acts downward on the deformed reinforcing bar 6, but the deformed reinforcing bar 6 is inserted into the insertion hole 22 of the bearing plate 21. Therefore, an upward bearing reaction force is generated in the bearing plate 21 so as to surround the deformed reinforcing bar 6. Thus, the deformed reinforcing bar 6 and the bearing plate 21 are centered on the material axis of the deformed reinforcing bar 6. A substantially conical compression strut 23 is formed.

  The compressive struts 23 support the tensile force acting on the steel pipe 2, thus increasing the bending strength of the reinforced concrete body 8 and resisting the large forced rotational deformation received from the steel pipe 2.

  When a large pulling force acts on the steel pipe 2 and the entire cross section of the reinforced concrete body 8 is pulled, the above-described compression struts 23 are generated on the entire circumference and the entire stage of the bearing plate 21 provided on the inner surface of the steel pipe 2. These resist the large pulling force acting on the steel pipe 2 and are finally transmitted to the footing 4.

  As described above, according to the pier and footing joint structure 1 according to the present embodiment, the bearing plate 21 is attached to the inner surface of the steel pipe 2 so as to be embedded in the reinforced concrete body 8 formed in the steel pipe 2. At the same time, since the deformed rebar 6 is inserted through the insertion hole 22 formed in the bearing plate, the steel pipe 2 is forced to be deformed by a horizontal force acting on the head of the pier 3 or in the steel pipe 2. When a large pulling force is applied, a substantially conical compression strut 23 centering on the material axis of the deformed reinforcing bar 6 is formed between the deformed reinforcing bar 6 and the bearing plate 21 arranged in the tensile cross section.

  That is, since the bearing plate 21 is disposed so as to surround the deformed reinforcing bar 6, a bearing reaction force balanced with the tensile adhesion stress of the deformed reinforcing bar 6 is generated in a wide area range of the bearing plate 21, and between these The compression strut 23 having a large volume is formed.

  Therefore, the tensile strength and bending strength at the joint with the footing 4 can be remarkably improved.

  Further, since the resultant horizontal component force of the compression struts 23 formed in a conical shape is substantially canceled out, the force that the filled concrete 7 tends to expand laterally becomes significantly smaller than in the conventional case, and the restraining action by the steel pipe 2 is reduced. Together, it is also possible to suppress cracks in the concrete 7.

  Although not particularly mentioned in the present embodiment, when the pier 3 is long, a steel pipe similar to the steel pipe can be successively added onto the steel pipe 2 by welding or the like.

  Further, in this embodiment, the mold material 12 has a function of temporarily receiving the weight of the steel pipe 2, but the steel pipe 2 is provisionally received by another known means, and the mold material 12 has only the function of the mold. You may make it have. In this case, it is arbitrary whether the mold material 12 is removed after the concrete is hardened.

  Further, in the present embodiment, because the steel pipe 2 is a square steel pipe, the bearing member is configured by the rectangular frame-shaped bearing plate 21, but the bearing member according to the present invention is not limited to such a shape. If the steel pipe is a circular steel pipe, it can be an annular bearing plate, and if it is a polygonal steel pipe, it can be a polygonal frame bearing plate.

  Moreover, in this embodiment, although the supporting member was comprised with the bearing plate 21 in which the penetration hole 22 which penetrates the deformed reinforcement 6 was formed, the bearing member which concerns on this invention is not limited to this structure, Any supporting member may be used as long as it can form a substantially conical compression strut with the steel pipe joining rebar.

  For example, as shown in FIG. 7 (a), a rectangular frame-shaped bearing plate having a width W along the direction from the inner surface of the steel pipe 2 toward its center and having a notch 71 formed at the edge of the steel pipe center side. 72 can constitute the bearing member of the present invention.

  In such a modified example, because the deformed reinforcing bar 6 is fitted into the notch 71, there is no supporting portion that balances the tensile adhesion stress of the deformed reinforcing bar 6 on the inner side of the steel pipe center side edge, and therefore the compression strut 23a. Is a semi-conical shape as shown in FIG.

  However, the bearing area is greatly increased as compared with the prior art, and the above-described effects are similarly applied to this modification. In addition, according to the present modification, the deformed reinforcing bar 6 can be fitted from the side, so that an effect of high workability during construction is achieved. In addition, since the joining method in this modification is substantially the same as that of the above-described embodiment, detailed description thereof is omitted here.

It is a figure which shows the junction structure 1 of the bridge pier and footing which concern on this embodiment, (a) is a longitudinal cross-sectional view, (b) is sectional drawing which follows an AA line. It is the figure which showed the bearing plate 21 and its attachment condition, (a) is a whole perspective view, (b) is a top view. The construction procedure figure which showed the procedure of the joining method of the bridge pier and footing which concern on this embodiment. The construction procedure figure which showed the procedure of the joining method of the bridge pier and footing which concern on this embodiment continuously. The figure which showed the effect | action of the joining structure and method of the bridge pier and footing which concern on this embodiment. The figure which similarly showed the effect | action of the joining structure and method of the bridge pier and footing which concern on this embodiment. The figure which showed the joining structure of the bridge pier and footing which concern on a modification.

Explanation of symbols

1 Joint structure of pier and footing 2 Steel pipe 3 Bridge pier 4 Footing 6 Deformed bar (steel pipe joint)
7 Filled concrete 8 Reinforced concrete body 12 Formwork materials 21 and 72 Bearing plate (bearing member)
22 Insertion hole 23, 23a Compression strut 71 Notch

Claims (7)

A steel pipe disposed above the footing in a vertical posture so that a predetermined gap is formed between the footing formed of reinforced concrete and the upper surface of the footing, and a steel pipe having one end embedded in the footing Reinforced concrete body formed of concrete which is filled in the reinforcing steel for joining and the steel pipe and the other end of the reinforcing steel for joining steel pipe is embedded, and the bearing pressure attached to the inner surface of the steel pipe so as to be buried in the reinforced concrete body And forming the bearing member so as to surround the steel pipe joining rebar so that a substantially conical compression strut centering on the material axis of the steel pipe joining rebar is formed. The joint structure of the pier and footing characterized by The bearing member is an annular, rectangular frame or polygonal frame bearing plate having a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe and having an insertion hole in the vicinity of the width center. The joining structure of a bridge pier and a footing according to claim 1, wherein the steel pipe joining rebar is inserted through the insertion hole. The bearing member is supported in an annular, rectangular frame or polygonal frame shape having a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe and having a notch formed at the edge of the steel pipe center. The joining structure of a bridge pier and a footing according to claim 1, wherein the steel pipe joining rebar is arranged in the notch while being constituted by a pressure plate. In the joining method of the pier and footing that joins the pier composed of steel pipes to the footing formed of reinforced concrete,
The steel pipe joining rebar is formed so that one end of the steel pipe joining rebar is embedded in the footing, and a predetermined gap is formed between the lower end of the steel pipe and the upper surface of the footing. The steel pipe is positioned above the footing in a vertical posture so that the other end of the steel pipe is placed in the steel pipe, the gap is closed with a predetermined formwork material, and the other end of the steel pipe joining rebar is buried. The steel pipe is filled with concrete to form a reinforced concrete body in the steel pipe, and a supporting member is attached to the inner surface of the steel pipe so as to be embedded in the reinforced concrete body, and the steel pipe joint By forming the bearing member so as to surround the reinforcing steel bar, a substantially conical compression strut centered on the material axis of the steel pipe joining reinforcing bar is formed. Method of joining the piers and footings characterized and. The bearing member is an annular, rectangular frame or polygonal frame bearing plate having a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe and having an insertion hole in the vicinity of the width center. The joining method of a bridge pier and a footing according to claim 4, wherein the steel pipe joining rebar is inserted into the insertion hole while being configured. The bearing member is supported in an annular, rectangular frame or polygonal frame shape having a predetermined width along the direction from the inner surface of the steel pipe toward the center of the steel pipe and having a notch formed at the edge of the steel pipe center. The joining method of the bridge pier and footing of Claim 4 which comprised with the pressure plate and arrange | positioned the said steel pipe joining rebar in the said notch. The said frame material is comprised so that the vertical load of the said steel pipe can be temporarily received, and after the concrete with which the said steel pipe was filled hardens | cures, the said frame material is removed. Joining method of pier and footing.

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