Construction method for bridge pier

Abstract

To improve construction efficiency and reduce construction time.SOLUTION: Multiple steel pipe sheet piles 40 are arranged around the entire circumference of the construction site of a column part 21, and after the column part 21 is constructed inside the steel pipe sheet piles 40, a beam part 22 is constructed on the head part of the column part 21. The construction method for a pier 20 includes a step to construct the column part 21, a step in which a beam formwork 10 for constructing the beam part 22 is installed in a state of being supported on the steel pipe sheet piles 40 via a beam bottom support structure 30 that supports the bottom of the beam formwork 10, a step to fill the inside of the beam formwork 10 with concrete material to construct the beam part 22, and a step in which, after constructing the beam part 22, the beam formwork 10, the beam bottom support structure 30, and the steel pipe sheet piles 40 are removed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a construction method for a bridge pier. [Background technology]

[0002] Conventionally, a bridge pier has been constructed by providing multiple steel pipe sheet piles arranged around the entire circumference of the construction site of the columns, constructing the columns inside the steel pipe sheet piles, and then constructing beams on the tops of the columns (see, for example, Patent Document 1). Specifically, the columns are first constructed, the steel pipe sheet piles are removed, and beam supports are installed below the construction site of the beams. Then, scaffolding and formwork are assembled on the beam supports to construct the beams. Then, after construction of the beams is completed, the bridge pier is constructed in the following procedure: the superstructure is constructed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-148108 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional bridge pier construction method described above had the following problems. The beams of the bridge pier are large in scale, and a large amount of concrete needs to be poured into the formwork, so it takes many days to complete curing. For this reason, there is a demand for improving the construction efficiency of the beams and shortening the construction period for the entire bridge pier, and there is room for improvement in this regard.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a bridge pier construction method that can improve construction efficiency and shorten the construction period. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the method of constructing a bridge pier according to the present invention is a method of constructing a bridge pier in which a plurality of steel pipe sheet piles are arranged around the entire circumference of a construction location of a column, the column is constructed inside the steel pipe sheet piles, and then a beam is constructed on the head of the column, the method comprising the steps of: constructing the column; installing a beam formwork for constructing the beam while being supported on the steel pipe sheet pile via a beam-bottom support structure that supports the bottom of the beam formwork; constructing the beam by filling the inside of the beam formwork with concrete material; and after constructing the beam, removing the beam formwork, the beam-bottom support structure and the steel pipe sheet pile.

[0007] Thus, according to the bridge pier construction method of the present invention, after the construction of the columns is completed, the beam-bottom support structure and the beam formwork are installed by supporting them on the steel pipe sheet piles provided for the construction of the columns, and the beam is constructed by filling the inside of the beam formwork with concrete material. Then, after the construction of the beam is completed, the construction procedure is to remove the steel pipe sheet piles together with the beam formwork and the beam-bottom support structure. In other words, since the removal of the steel pipe sheet piles is the final process, the work of the next bridge pier to be constructed can be started during the removal of the steel pipe sheet piles, which improves construction efficiency and shortens the construction period. In addition, in the present invention, by making the removal of the steel pipe sheet piles the final process, construction of the beam section, which requires a long curing time for the concrete material poured inside the beam formwork, can be carried out early, thereby shortening the construction period.

[0008] In addition, in the construction method of a bridge pier according to the present invention, it is preferable that a support foundation having an extension bracket extending radially inward and outward from the steel pipe sheet pile is provided, and the beam-bottom support structure is supported from below by the support foundation.

[0009] In this case, the steel pipe sheet piles used in the construction of the columns are provided with overhanging brackets, which allows the installation area of ​​the support foundation that supports the beam-bottom support structure to be expanded. Therefore, the load received from the beam formwork can be widely distributed through the beam-bottom support structure without being concentrated on the support foundation, which prevents the support foundation from buckling, and allows the beam formwork and beam-bottom support structure to be installed in a stable structure, allowing the installation work to be carried out efficiently.

[0010] In addition, in the pier construction method according to the present invention, it is preferable that at least one of the beam formwork and the beam-bottom support structure is divided into a plurality of units.

[0011] In this case, the beam formwork and the beam-base support structure can be divided and unitized at a location other than the installation location. For example, the beam formwork and the beam-base support structure that have been unitized by assembling them on the ground can be carried to a designated location, and the units can be joined together to improve construction efficiency.

[0012] In addition, in the bridge pier construction method according to the present invention, it is preferable that after constructing the beam portion, a superstructure is installed on the beam portion, and after the superstructure is installed, the steel pipe sheet pile is removed.

[0013] In this case, by installing the superstructure after constructing the beam section and before removing the steel pipe sheet piles, construction efficiency can be improved and the construction period can be shortened.

[0014] In addition, in the pier construction method of the present invention, it is preferable that the lower part of the beam portion forms a convex curved surface that is convex downward, and the beam formwork forms an R-shape that corresponds to the convex curved surface of the beam portion.

[0015] In this case, even if an R-shaped convex curved surface is formed at the protruding part of the beam, such as in a river bridge pier, the construction of the beam can be carried out efficiently by using a beam formwork shaped to correspond to the convex curved surface.

[0016] In addition, in the bridge pier construction method of the present invention, after removing the beam formwork and the beam bottom support structure, a guide rail and a crane guided by the guide rail are provided at the bottom of the beam portion, and it is preferable that the guide rail extends circumferentially along the arrangement direction of the steel pipe sheet piles directly above the steel pipe sheet piles arranged in the circumferential direction.

[0017] In this case, since the guide rail and the crane are provided on the constructed beam, the steel pipe sheet pile used for the construction of the beam can be efficiently removed directly below the beam using the crane. Since the steel pipe sheet pile below the beam can be removed in this way, the removal work can be efficiently performed even if the head space above the steel pipe sheet pile is low.

[0018] In addition, in the bridge pier construction method according to the present invention, it is preferable that the upper part of the steel pipe sheet pile is filled with filler concrete.

[0019] In this case, by filling the upper part of the steel pipe sheet pile with filled concrete, the rigidity of the upper part of the steel pipe sheet pile can be increased, and therefore, buckling of the steel pipe sheet pile due to the load when concrete is filled into the beam formwork can be prevented.

[0020] In addition, in the pier construction method according to the present invention, it is preferable that the steel pipe sheet pile is provided with partition members which divide the filled concrete into layers in the vertical direction.

[0021] In this case, the partition member serves as a cutting section that divides the filled concrete in the steel pipe sheet pile into upper and lower parts. The steel pipe sheet pile can be cut horizontally at the transverse position where the partition member is located by gas cutting. Therefore, the steel pipe sheet pile in the portion filled with filled concrete can be cut at an appropriate height and efficiently removed in blocks.

[0022] In addition, in the bridge pier construction method according to the present invention, it is preferable that the filled concrete has a vertical groove that forms a gap between itself and an inner peripheral surface of the steel pipe sheet pile.

[0023] In this case, the vertical grooves become the cutting parts that divide the filled concrete in the steel pipe sheet pile vertically. The steel pipe sheet pile can be cut vertically at the positions where the vertical grooves are arranged by gas cutting. Therefore, the steel pipe sheet pile in the part filled with the filled concrete can be divided in the circumferential direction and efficiently removed in the form of blocks. Effect of the Invention

[0024] According to the bridge pier construction method of the present invention, construction efficiency can be improved and construction time can be shortened. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a side view showing a construction method for a bridge pier according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the bridge pier shown in FIG. 1, seen obliquely from above. [Diagram 3] FIG. 2 is a perspective view of the bridge pier shown in FIG. 1, seen obliquely from below. [Figure 4] FIG. 4 is a side view showing the construction state of the beam portion. [Diagram 5] FIG. 2 is a plan view of the beam-bottom support structure from above. [Figure 6] This is a vertical cross-sectional view of a steel pipe sheet pile during beam construction. [Figure 7] FIG. 7 is a cross-sectional view taken along line II shown in FIG. 6, showing a horizontal cross-sectional view of the steel pipe sheet pile. [Figure 8] This is an oblique view showing the configuration of the beam formwork and the beam bottom support structure. [Figure 9] 9 is a perspective view showing the configuration of the beam formwork and the beam-bottom support structure, seen from a different angle than in FIG. 8. FIG. [Figure 10] FIG. 10 is a perspective view in which the beam formwork is omitted in FIG. [Figure 11] FIG. 1 is a diagram showing the construction flow of a bridge pier. [Figure 12] FIG. 2 is a perspective view showing the state in which the steel pipe sheet pile has been removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, a bridge pier construction method according to an embodiment of the present invention will be described with reference to the drawings.

[0027] As shown in Figures 1, 2 and 3, the construction method for the bridge pier 20 of this embodiment is adopted in a construction in which a plurality of steel pipe sheet piles 40 are arranged around the entire circumference of the construction location of the column section 21, the column section 21 is constructed inside the steel pipe sheet piles 40, and then the beam section 22 is constructed on the head of the column section 21.

[0028] The pier 20 is made of reinforced concrete and includes a column portion 21 and a beam portion 22. In this embodiment, the pier 20 is constructed in a river. Since the column portion 21 is submerged in water, a plurality of steel pipe sheet piles 40 are constructed around the entire circumference of the construction location of the column portion 21 during construction. The steel pipe sheet piles 40 adjacent in the circumferential direction are connected to each other in a watertight state. Then, at least during construction of the column portion 21, the water inside the plurality of steel pipe sheet piles 40 arranged in a circular shape is drained and removed, making it possible to carry out work inside the steel pipe sheet piles 40.

[0029] The pillar section 21 is erected on a foundation 25. In a plan view from above, both end sections 21a of the pillar section 21 in a first direction X1 perpendicular to the bridge axis J (see FIG. 2) of the pier 20 are formed into an arc shape in plan view. Here, a direction parallel to the bridge axis J in plan view and perpendicular to the first direction X1 is referred to as a second direction X2.

[0030] The beam portion 22 has a beam main body portion 23 that is placed on the upper portion of the column portion 21 and is integrally connected thereto, and an overhanging portion 24 that protrudes from the beam main body portion 23 in the first direction X1.

[0031] The bottom 24a of the overhanging portion 24 forms a horizontal flat bottom surface 241 on the column portion 21 side, and an upwardly inclined bottom surface 242 that gradually inclines upward in the first direction X1 from the flat bottom surface 241 toward the direction away from the column portion 21 in a side view seen from the second direction X2. The inclined bottom surface 242 has an R-shape in which the central portion of the lower portion in the width direction (second direction) forms a convex curved surface 24b that is convex downward when seen from the first direction X1.

[0032] As shown in Figures 4 and 5, the beam section 22 is constructed using a beam formwork 10, which serves as a formwork for assembling the rebar of the beam section 22 and pouring the concrete, and a beam bottom support structure 30, which supports the bottom 10a of the beam formwork 10. The beam formwork 10 and the beam-bottom support structure 30 are supported from below by a support foundation 50 fixed to a steel pipe sheet pile 40 .

[0033] 6 and 7, the upper portion 40a of the steel pipe sheet pile 40 is filled with filled concrete 41. The steel pipe sheet pile 40 is provided with a plurality of partition plates 42 (partition members) spaced apart in the vertical direction to separate the filled concrete 41 into layers in the vertical direction. As a result, the filled concrete 41 is divided into a plurality of layers in the vertical direction.

[0034] The partition plate 42 becomes a cutting portion that divides the steel pipe sheet pile 40 into upper and lower parts when the steel pipe sheet pile 40 is removed. A plate-shaped member made of, for example, wood that is easily combusted by gas cutting is used as the partition plate 42. That is, the steel pipe sheet pile 40 is cut horizontally by gas cutting at the transverse position where the partition plate 42 is disposed.

[0035] The vertical distance between the partition plates 42 is set based on the weight of one block to be divided when removing the steel pipe sheet pile 40. For example, the size and dimensions of one block are determined by the lifting load of a crane 60 (see FIG. 12), which will be described later, and the distance between the partition plates 42 is set based on this.

[0036] 7, the filled concrete 41 has a plurality of (four in this example) vertical grooves 41a that form a gap S between the filled concrete 41 and the inner peripheral surface 40b of the steel pipe sheet pile 40. The vertical grooves 41a are formed by filling the filled concrete 41 with angle steel materials 43 arranged between the filled concrete 41 and the inner peripheral surface 40b of the steel pipe sheet pile 40. The angle steel materials 43 are arranged along the inner peripheral surface 40b of the steel pipe sheet pile 40 with their longitudinal directions facing the up-down direction and their corner portions 43a facing the center of the steel pipe sheet pile 40. The steel pipe sheet pile 40 is cut in the vertical direction (up-down direction) by gas cutting at the longitudinal cross-sectional position where the vertical grooves 41a are arranged.

[0037] As shown in Figures 4 and 5, the support foundation 50 has overhang brackets 51, 52 that overhang radially inward and outward from the steel pipe sheet pile 40, and a receiving support 53 assembled on the overhang brackets 51, 52.

[0038] H-shaped steel is used for the overhang brackets 51, 52. The inner overhang bracket 51 extends in the first direction X1 from the outer circumferential surface 40c of the steel pipe sheet pile 40 in a direction approaching the column portion 21. The inner overhang bracket 51 is provided on each of the five steel pipe sheet piles 40 facing the overhang portion 24 side of the column portion 21 in the first direction X1, and is arranged at intervals in the second direction X2. The inner overhang bracket 51 is supported from below by a diagonal member 511.

[0039] The outer protruding brackets 52 extend from the outer peripheral surface 40c of the steel pipe sheet pile 40 in a direction away from the column portion 21 in the first direction X1. The outer protruding brackets 52 are provided on each of the five steel pipe sheet piles 40 and are arranged at intervals in the second direction X2. The outer protruding brackets 52 are supported from below by diagonal members 521.

[0040] The inner protruding bracket 51 is installed at a position lower than the outer protruding bracket 52. The outer protruding bracket 52 is provided at a height substantially flush with the upper end 40d of the steel pipe sheet pile 40.

[0041] As shown in Figures 4, 5, 8, 9 and 10, the receiving support 53 supports the beam formwork 10 and the beam-bottom support structure 30 from below by appropriately combining girder members 531, supports 532 and supports 533 vertically, horizontally and vertically. The girder member 531 is made of an H-shaped steel and is arranged on the extending brackets 51, 52 with its longitudinal direction extending along the second direction X2. The girder member 531 on the inner extending bracket 51 is fixed to the inner extending bracket 51 via supports 533. Supports 532 are assembled on the girder members 531 arranged at intervals in the first direction X1.

[0042] As shown in Figures 8 and 9, the beam formwork 10 comprises a first formwork portion 11 having a shape corresponding to the flat bottom surface 241 (see Figure 1) of the protrusion portion 24 of the beam portion 22, and a second formwork portion 12 having an R-shaped curved inner surface 12a that follows the inclined bottom surface 242 (convex curved surface 24b).

[0043] The first formwork part 11 is plate-shaped and is fixed in a state in which it is placed on a first receiving member 311 of the beam-bottom support structure 30 (described later) with the plate surface facing horizontally. The first formwork part 11 forms a curved recess 11a corresponding to the end 21a of the column part 21 (see FIG. 2) in a plan view.

[0044] The second formwork section 12 has a bottom formwork 121 having a curved inner surface 12a, and a tip formwork 122 corresponding to the protruding tip surface 24c (see FIG. 1) of the protruding section 24. The outer surface 12b of the bottom formwork 121 is a flat inclined surface. The second formwork section 12 is fixed in a state in which it is placed on a second receiving member 321 of the beam-bottom support structure 30 described later with the outer surface 12b inclined.

[0045] The beam formwork 10 is divided into a plurality of beam formwork units 10A. The beam formwork units 10A are divided, for example, into a first direction X1 and a second direction X2. Each beam formwork unit 10A is unitized, for example, on the ground or in a factory. These plurality of beam formwork units 10A are arranged at the assembly position, and adjacent beam formwork units 10A are connected to each other by bolt fastening or the like to install an integrated beam formwork 10.

[0046] 4, 5 and 10, the beam-bottom support structure 30 includes a first beam-bottom support part 31 that supports the first formwork part 11 from below, and a second beam-bottom support part 32 that supports the second formwork part 12 from below. The first beam-bottom support part 31 and the second beam-bottom support part 32 are installed on a receiving support 53 of the support foundation 50.

[0047] The first beam bottom support portion 31 includes a plurality of first support members 311 arranged at intervals in the second direction X2 with their material axis direction facing the first direction X1. The first support members 311 are square steel pipes. The first formwork portion 11 of the beam formwork 10 is fixed onto the plurality of first support members 311. The first beam bottom support portion 31 includes a curved member 33 that corresponds to the end portion 21a of the column portion 21 in a plan view.

[0048] The second beam bottom support part 32 is a support structure provided integrally with the first beam bottom support part 31 and framed in a substantially triangular shape in a side view seen from the second direction X2. The second beam bottom support part 32 includes a second support member 321 that holds the second formwork part 12 of the beam formwork 10 from diagonally below, and a support member 322 that supports the second support member 321 from below. The second beam bottom support part 32 is disposed in the space H on the outer surface 12b side of the second formwork part 12 on the receiving support 53 of the support foundation 50 described above.

[0049] The second support member 321 is a square steel pipe, and is arranged so that the length direction of this square steel pipe is aligned along the inclination direction of the second formwork portion 12 of the beam formwork 10 (the inclination direction of the inclined bottom surface 242 of the overhanging portion 24) when viewed from the side. A plurality of second support members 321 are arranged at intervals in the second direction X2. The support material 322 has a structure in which steel materials are combined so as to support a plurality of second support materials 321 arranged diagonally between the support material 322 and the shoring foundation 50, and is provided integrally with the second support materials 321.

[0050] The beam-bottom support structure 30 is divided into a plurality of beam-bottom support units 30A. The beam-bottom support units 30A are divided, for example, into a first direction X1 and a second direction X2. Each beam-bottom support unit 30A is unitized, for example, on the ground or in a factory. These multiple beam-bottom support units 30A are arranged at the assembly position, and adjacent beam-bottom support units 30A are connected to each other by bolt fastening or the like to install an integrated beam-bottom support structure 30.

[0051] Next, a construction procedure for constructing the above-mentioned bridge pier 20 will be specifically described with reference to the construction flow of FIG.

[0052] 1 to 3, the column section 21 is constructed on the foundation 25 that has been constructed in advance inside the frame surrounded by a plurality of steel pipe sheet piles 40 that are constructed in the circumferential direction (step S1). The column section 21 is constructed by assembling a formwork (not shown), assembling reinforcing bars and the like in the formwork, and then pouring concrete.

[0053] Next, as shown in Fig. 4, in step S2, a shoring foundation 50 is installed. Specifically, a plurality of overhang brackets 51, 52 are attached to the outer peripheral surface 40c of the steel pipe sheet pile 40 so as to overhang radially inward and outward. Then, a receiving shoring 53 is assembled on the overhang brackets 51, 52. The steel pipe sheet piles 40 used at this time are the steel pipe sheet piles 40 located below the overhanging portion 24 of the beam portion 22 to be constructed. That is, the five steel pipe sheet piles 40 shown in Fig. 5 are to be used, and the other steel pipe sheet piles 40 may be removed, for example, in parallel with the installation work of the shoring foundation 50.

[0054] 6 and 7, before or at the same time as the step of installing the shoring foundation 50, filler concrete 41 is poured into the upper part 40a of the steel pipe sheet pile 40 to be used. When pouring the filler concrete 41, a partition plate 42 for forming the filler concrete 41 in layers and angle steel members 43 for forming vertical grooves 41a between the filler concrete 41 and the steel pipe sheet pile 40 are provided. By filling the upper part 40a of the steel pipe sheet pile 40 with the filler concrete 41 in this way, buckling of the steel pipe sheet pile 40 due to the load when concrete is filled into the beam formwork 10 is prevented.

[0055] Thereafter, as shown in Fig. 4 and Fig. 8 to Fig. 10, in step S3, the beam-bottom support structure 30 is installed on the shoring foundation 50. For example, the beam-bottom support structure 30 is installed by sequentially joining a plurality of beam-bottom support units 30A that have been unitized by ground assembly. As a result, the first beam-bottom support part 31 and the second beam-bottom support part 32 are provided on the shoring foundation 50, and the beam-bottom support structure 30 is supported by the shoring foundation 50 from below.

[0056] After the beam-bottom support structure 30 is installed, in step S4, as shown in Figures 8 and 9, the beam formwork 10 for constructing the beam section 22 is installed on the beam-bottom support structure 30 while being supported by the steel pipe sheet piles 40. For example, the beam formwork 10 is installed by sequentially joining together a plurality of beam formwork units 10A that have been unitized by ground assembly. As a result, the beam formwork 10 in which the first formwork portion 11 and the second formwork portion 12 are integrated via the beam-bottom support structure 30 is provided on the support foundation 50. As a result, the beam formwork 10 having a shape corresponding to the bottom 24a of the overhanging portion 24 of the beam section 22 to be constructed is installed.

[0057] Next, as shown in Figures 8 and 9, in step S5, after assembling reinforcing bars inside the beam formwork 10, the inside of the beam formwork 10 is filled with concrete material to construct the bottom 24a of the overhanging portion 24 of the beam portion 22. After that, a formwork (not shown) is assembled for the beam main body portion 23 and the installation location of the overhanging portion 24 other than the location where concrete was poured using the beam formwork 10. This formwork has a different configuration from the beam formwork 10 for pouring the bottom portion 24a described above, and a well-known formwork is used. In this way, the beam portion 22 is constructed on the head of the column portion 21.

[0058] After the construction of the beam portion 22, a superstructure (not shown) is installed on the beam portion 22 in step S6.

[0059] Next, in step S7, after constructing the beam section 22, the beam formwork 10 and the beam-bottom support structure 30 are removed. The removal work in step S7 can be performed in parallel with the installation of the superstructure in step S6. The removal procedure is the reverse of the assembly procedure, in which the beam formwork 10 is first dismantled and removed, and then the beam-bottom support structure 30 is removed. In addition, in step S8, after the beam-bottom support structure 30 is removed, the support foundation 50 is removed.

[0060] Next, as shown in Fig. 12, in step S9, the steel pipe sheet pile 40 is removed after the removal of the shoring foundation 50. Note that, during the process of removing the steel pipe sheet pile 40 in step S9, it is possible to proceed to the construction of the beam section 22 to be constructed next. That is, for example, the removal of the steel pipe sheet pile 40 and the installation of the shoring foundation 50, the beam-bottom support structure 30, and the beam formwork 10 for the construction of the beam section 22 to be constructed next can be carried out in parallel.

[0061] The steel pipe sheet piles 40 are removed using a crane 60 provided at the overhanging portion 24 of the constructed beam portion 22. This crane 60 may be installed after the shoring foundation 50 is removed, or may be installed while the shoring foundation 50 remains, i.e., after the beam-bottom support structure 30 is removed. First, a guide rail 61 is installed above the steel pipe sheet piles 40 at the overhanging portion 24 of the beam portion 22, and a crane 60 guided by this guide rail 61 is provided. The guide rail 61 extends in the circumferential direction along the arrangement direction of the steel pipe sheet piles 40 directly above the steel pipe sheet piles 40 arranged in the circumferential direction. By using the crane 60 in this manner, the steel pipe sheet piles 40 can be removed efficiently.

[0062] The upper portion 40a of the steel pipe sheet pile 40 filled with the filled concrete 41 is cut vertically at the position of the vertical grooves 41a by gas cutting, and cut horizontally at the position of the partition plate 42, and the steel pipe sheet pile 40 containing the filled concrete 41 is cut into blocks and removed. The portion consisting of only the steel pipe sheet pile 40 is removed by horizontally gas cutting only the steel pipe at an appropriate height.

[0063] Next, the operation of the above-mentioned construction method for the pier 20 will be described in detail with reference to the drawings. In the construction method for the pier 20 according to this embodiment, a plurality of steel pipe sheet piles 40 are arranged around the entire periphery of the construction location of the column portion 21, and after the column portion 21 is constructed inside the steel pipe sheet piles 40, the beam portion 22 is constructed on the head of the column portion 21. The construction method for the pier 20 includes the steps of constructing the column portion 21, installing the beam formwork 10 for constructing the beam portion 22 in a state supported by the steel pipe sheet pile 40 via the beam bottom support structure 30 that supports the bottom of the beam formwork 10, constructing the beam portion 22 by filling the inside of the beam formwork 10 with concrete material, and after constructing the beam portion 22, removing the beam formwork 10, the beam bottom support structure 30, and the steel pipe sheet pile 40.

[0064] In this embodiment, after the construction of the column section 21 is completed, the beam-bottom support structure 30 and the beam formwork 10 are installed while being supported by the steel pipe sheet pile 40 provided for the construction of the column section 21, and the beam section 22 is constructed by filling the inside of the beam formwork 10 with concrete material. Then, after the construction of the beam section 22 is completed, the construction procedure is such that the beam formwork 10 and the beam-bottom support structure 30 are removed together with the steel pipe sheet pile 40. That is, since the removal of the steel pipe sheet pile 40 is the final process, the work of the pier 20 to be constructed next can be started during the removal of the steel pipe sheet pile 40, which improves construction efficiency and shortens the construction period.

[0065] In addition, in this embodiment, by making the removal of the steel pipe sheet piles 40 the final process, construction of the beam section 22, which requires a long curing time for the concrete material poured inside the beam formwork 10, can be carried out early, thereby shortening the construction period.

[0066] In this embodiment, a support base 50 is provided having protruding brackets 51, 52 protruding radially inward and outward of the steel pipe sheet pile 40. The beam-bottom support structure 30 is supported by the support base 50 from below. Therefore, the overhang brackets 51, 52 are provided on the steel pipe sheet piles 40 used in the construction of the column section 21, so that the installation area of ​​the support foundation 50 supporting the beam-bottom support structure 30 can be expanded. Therefore, the load received from the beam formwork 10 can be widely dispersed through the beam-bottom support structure 30 without being concentrated on the support foundation 50, so that buckling of the support foundation 50 can be suppressed, and the beam formwork 10 and the beam-bottom support structure 30 can be provided with a stable structure, and installation work can be performed efficiently.

[0067] In this embodiment, at least one of the beam formwork 10 and the beam-bottom support structure 30 is divided into a plurality of units. Therefore, the beam formwork 10 and the beam-bottom support structure 30 can be divided and unitized at a location other than the installation location. For example, the beam formwork 10 and the beam-bottom support structure 30 that have been unitized by assembling them on the ground can be carried to a predetermined location, and the unitized pieces can be joined together to improve construction efficiency.

[0068] In this embodiment, after the construction of the beam portion 22, a superstructure is installed on the beam portion 22. After the superstructure is installed, the steel pipe sheet piles 40 are removed. Therefore, by installing the superstructure after construction of the beam section 22 and before removing the steel pipe sheet piles 40, construction efficiency can be improved and the construction period can be shortened.

[0069] In this embodiment, the lower portion of the beam portion 22 forms a convex curved surface 24b that is convex downward. The beam formwork 10 forms an R shape corresponding to the convex curved surface 24b of the beam portion 22. Therefore, even if an R-shaped convex curved surface 24b is formed on the protruding portion of the beam portion 22, such as a river bridge pier, the construction of the beam portion 22 can be carried out efficiently by using a beam formwork 10 having a shape that corresponds to the convex curved surface 24b.

[0070] In this embodiment, after removing the beam formwork 10 and the beam-bottom support structure 30, a guide rail 61 and a crane 60 guided by the guide rail 61 are provided under the beam portion 22. The guide rail 61 extends in the circumferential direction along the arrangement direction of the steel pipe sheet piles 40 directly above the steel pipe sheet piles 40 arranged in the circumferential direction. Therefore, since the guide rails 61 and the crane 60 are provided on the constructed beam section 22, the crane 60 can be used to efficiently remove the steel pipe sheet piles 40 used in the construction of the beam section 22 directly below the beam section 22. Since the steel pipe sheet piles 40 below the beam section 22 can be removed in this manner, the removal work can be performed efficiently even if the headroom above the steel pipe sheet piles 40 is low.

[0071] In addition, in this embodiment, since the filled concrete 41 is filled in the upper part of the steel pipe sheet pile 40, the rigidity of the upper part of the steel pipe sheet pile 40 can be increased. Therefore, the buckling of the steel pipe sheet pile 40 due to the load when the beam formwork 10 is filled with concrete material can be prevented.

[0072] In addition, in this embodiment, the steel pipe sheet pile 40 includes partition plates 42 that separate the filled concrete 41 into layers in the vertical direction. Therefore, the partition plate 42 serves as a cutting section that divides the filled concrete 41 in the steel pipe sheet pile 40 into upper and lower parts. The steel pipe sheet pile 40 can be cut horizontally by gas cutting at the transverse position where the partition plate 42 is placed. Therefore, the steel pipe sheet pile 40 in the portion filled with the filled concrete 41 can be cut at an appropriate height and efficiently removed in the form of blocks.

[0073] In this embodiment, the filled concrete 41 has vertical grooves 41 a that form gaps between the filled concrete 41 and the inner circumferential surface of the steel pipe sheet pile 40 . Therefore, the vertical grooves 41a become cutting portions that vertically divide the filled concrete 41 in the steel pipe sheet pile 40. The steel pipe sheet pile 40 can be cut vertically by gas cutting at the positions where the vertical grooves 41a are arranged. Therefore, the steel pipe sheet pile 40 in the portion filled with the filled concrete 41 can be divided in the circumferential direction and efficiently removed in the form of blocks.

[0074] As described above, the construction method for the pier 20 according to this embodiment can improve construction efficiency and shorten the construction period.

[0075] Although an embodiment of the bridge pier construction method according to the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention.

[0076] For example, the shape, size, components, quantity, arrangement of components, etc. of the beam formwork 10, beam base support structure 30, and support foundation 50 can be changed as appropriate depending on conditions such as the shape and size of the beam portion 22 and the weight of the concrete material to be filled in the beam formwork 10.

[0077] For example, in this embodiment, a support foundation 50 having protruding brackets 51, 52 that protrude radially inward and outward from the steel pipe sheet pile 40 is provided, but the support foundation 50 is not limited to one having such protruding brackets 51, 52. The point is that the beam formwork 10 and the beam base support structure 30 are configured to be supported from below by the steel pipe sheet piles 40.

[0078] Furthermore, the lower part of the beam portion 22 is not limited to a shape having a convex curved surface 24b that is convex downward, and in this case, the beam formwork 10 is also not limited to a shape having an R shape corresponding to the convex curved surface 24b of the beam portion 22.

[0079] In addition, in this embodiment, at least one of the beam formwork 10 and the beam bottom support structure 30 is divided into multiple parts and unitized into a beam formwork unit 10A and a beam bottom support unit 30A, and each unit is joined together, but the configuration is not limited to this unitization, and the entire beam formwork 10 and beam bottom support structure 30 may be assembled at the installation site.

[0080] Furthermore, in this embodiment, after removing the beam formwork 10 and the beam bottom support structure 30, a guide rail 61 and a crane 60 guided by the guide rail 61 are provided at the bottom of the beam section 22, but it is also possible to omit such guide rail 61 and crane 60.

[0081] Furthermore, in this embodiment, the upper part 40a of the steel pipe sheet pile 40 is filled with filler concrete 41, and a partition plate 42 (partition member) and vertical groove 41a are provided, but the filler concrete 41, partition plate 42, and vertical groove 41a may be omitted.

[0082] In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0083] 10 Beam formwork 10A Beam formwork unit 10a bottom 20 Bridge Pier 21 Column section 22 Beam section 23 Beam body 24 Overhang 24a bottom 24b Convex curved surface 30 Beam support structure 30A Beam bottom support unit 40 Steel pipe sheet pile 40a Upper 40b Inner surface 41 Filled concrete 41a Vertical groove 42 Partition plate (partition member) 50 Shoring foundation 51 Inner extension bracket 52 Outer extension bracket 60 Crane 61 Guide rail X1 1st direction X2 2nd direction

Claims

1. A construction method for a bridge pier, comprising the steps of: providing a plurality of steel pipe sheet piles arranged around the entire circumference of a construction site of a column; constructing the column inside the steel pipe sheet piles; and constructing a beam on the head of the column; constructing the pillar; a step of installing a beam formwork for constructing the beam portion in a state in which the formwork is supported on the steel pipe sheet pile via a beam bottom support structure that supports a bottom of the beam formwork; A step of filling the inside of the beam formwork with concrete material to construct the beam portion; After constructing the beam portion, removing the beam formwork, the beam bottom support structure, and the steel pipe sheet pile; A construction method for bridge piers comprising the steps of:

2. A support foundation having an extension bracket extending radially inward and outward of the steel pipe sheet pile is provided, The bridge pier construction method according to claim 1 , wherein the beam-bottom support structure is supported from below by the support foundation.

3. The bridge pier construction method according to claim 1 , wherein at least one of the beam formwork and the beam-bottom support structure is divided into a plurality of units.

4. After the beam section is constructed, a superstructure is installed on the beam section; The bridge pier construction method according to claim 1, wherein the steel pipe sheet pile is removed after the superstructure is installed.

5. The lower portion of the beam portion forms a convex curved surface that is convex downward, The bridge pier construction method according to claim 1 , wherein the beam formwork is formed into an R-shape corresponding to the convex curved surface of the beam portion.

6. After removing the beam formwork and the beam bottom support structure, a guide rail and a crane guided by the guide rail are provided at the lower part of the beam portion, The bridge pier construction method according to any one of claims 1 to 5, wherein the guide rail extends circumferentially along an arrangement direction of the steel pipe sheet piles directly above the steel pipe sheet piles arranged in the circumferential direction.

7. The method for constructing a bridge pier according to claim 1, wherein an upper portion of the steel pipe sheet pile is filled with filler concrete.

8. The bridge pier construction method according to claim 7 , wherein the steel pipe sheet pile is provided with partition members that divide the filled concrete into layers in the vertical direction.

9. 9. The bridge pier construction method according to claim 7 or 8, wherein the filled concrete has vertical grooves that form gaps between the filled concrete and an inner peripheral surface of the steel pipe sheet pile.

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