JP6078196B1 - How to build steel columns - Google Patents

Abstract

The present invention provides a method for erection of a steel column for vertically supporting a steel column standing on a pile head of a cast-in-place pile. SOLUTION: A plurality of mechanical jacks 10 that extend and retract by meshing of gears are inserted into excavation holes 2 that are formed for constructing cast-in-place piles 3 and in which legs 4a of steel columns 4 are arranged. The steel columns 4 are arranged at the same depth at equal angular intervals around the column axis of the steel column 4 so that the directions are horizontal and face the axial center of the steel column 4, and the steel columns 10 are expanded and contracted by the expansion and contraction of these mechanical jacks 10. 4 support and verticality adjustment. [Selection] Figure 2

Description

  The present invention relates to a method for erection of a steel column erected on a pile head of a cast-in-place pile.

  When constructing a structure such as a bridge station building or overpass on a platform of a railway station (hereinafter abbreviated as “home”), a steel column for constructing the structure is erected on the platform. Such a steel column serves as a main column or column of the structure, and needs to be built with a perpendicularity within an allowable range.

  As a construction method to build a steel column on the platform, a hole is excavated to the support layer, which is a stable ground, and then a reinforcing steel cage is suspended in the excavation hole, and concrete is cast and cast in place in the hole. There is known a cast-in-place pile method (for example, Patent Document 1) in which a steel column is erected on the pile head of the cast-in-place pile. One method of excavating holes in the ground while ensuring stability so that the ground does not collapse is to fill the hole with mud and discharge the excavated sediment outside the hole by mud circulation. It is classified into a circulation excavation method (so-called BH method) and a reverse circulation excavation method (so-called TBH method). In any method, it is necessary to transport and install a dedicated excavator on the platform, and because it requires equipment for processing excavated sediment and circulating mud, a considerable amount is placed on the platform and around the platform. It is necessary to secure a large construction space.

  When construction is performed at the platform of a passenger station that is in operation, construction is performed exclusively during the limited time of the night from the last train to the first train to minimize the obstacles to passenger boarding and exiting and train operation. . However, freight trains may pass in the middle of the night, and the time that can be stopped to shut down the railway and close the track to ensure work safety is limited. It is limited to. As a result, construction tends to be prolonged.

  During the construction period, it will be necessary to take safety measures such as securing a passenger passage with a width of 1.5 meters or more on the platform, dividing the construction space with a fence, and taking measures to prevent the steel column from falling. Conventionally, as a means to adjust the erection (re-distortion) while preventing the steel column from overturning, multiple wire ropes (tra-wires) have been stretched on the steel column, and tension adjustment means such as cargo handling tools have been used. A method for adjusting the verticality of a column is known.

JP 2006-299748 A

  Wire ropes can be used when building steel columns vertically in stations such as platforms and between railway tracks, when space is available to allow multiple wire ropes to be stretched. Limited to. However, when the platform is narrow, or when the steel column is installed at the end of the platform, a steel column may be erected between the tracks. Due to the limited relationship, the wire cannot be deployed in a well-balanced manner on the four sides of the steel column, resulting in a complicated rope configuration and complicated installation adjustment (re-distortion) work, and insufficient wire tension angle. There is a problem that deterrence is insufficient. In addition, there is a problem in that it takes time to install and dismantle a concrete foundation that becomes a heavy stone at the lower end of the wire rope.

  If there is no space on the platform where the wire rope can be stretched, temporarily install a well girder that can be self-supported by connecting multiple steel columns with beams in other locations (yards), and then use a large heavy machine. There is also a method of lifting and transporting it on the platform and making it independent, but there is a problem that costs for securing large heavy machinery and yards are generated.

  Even if a space in which a wire rope can be stretched can be secured, there is a problem that a time-consuming work is forced because the time for the work is very limited as described above. In addition, as mentioned above, work hours per day are very limited, and construction tends to be prolonged, so wires stretched in the station premises and on the tracks exist for a long period of time. There is also a problem that may cause trouble and anxiety for the traffic of the elderly.

  The present invention has been made in view of these problems. For the construction of a structure, it has been conventionally possible to support a steel column that is erected on a pile head of a cast-in-place pile and to adjust the installation (redistortion). It is another object of the present invention to provide a method for installing a steel column that can be performed with high accuracy in a compact work space, and that can speed up the work and shorten the work period.

  The present invention is a method for erection of a steel column erected on the pile head of a cast-in-place pile, and is formed in the excavation hole formed to construct the cast-in-place pile and where the legs of the steel column are arranged A plurality of mechanical jacks that expand and contract due to the meshing of gears have the same depth at equal angular intervals around the column axis of the steel column so that each expansion and contraction direction is horizontal and faces the axis center of the steel column. Arranging and expanding or contracting one of the mechanical jacks after supporting the steel column substantially vertically by pressing the steel column placed on the pile head from each direction by each of the mechanical jacks To adjust the verticality of the steel column.

  Furthermore, the present invention optionally installs a earth retaining member on the inner wall surface of the excavation hole, and attaches the mechanical jack to the earth retaining member, whereby the mechanical jack is installed in the excavation hole. It may be arranged.

  Furthermore, the present invention optionally uses a jack holding member provided with an upward hook and a downward hook, and holds the downward hook on the earth retaining member, and fits the mechanical jack into the upward hook. The mechanical jack may be attached to the earth retaining member.

  Furthermore, the present invention optionally uses a jack holding member provided with an upward hook and a downward hook, and latches the downward hook on the earth retaining member, and the table moves by rotation of a feed screw on the upward hook. The mechanical jack may be attached to the earth retaining member by fitting a feed base so that the moving direction of the table is horizontally arranged and attaching the mechanical jack to the table.

The present invention is a method for erection of a steel column erected on a pile head of a cast-in-place pile, and is a drilling hole formed for constructing the cast-in-place pile and in which a leg portion of the steel column is arranged A liner plate is installed on the inner wall surface of the upper part of the cast-in-place pile, and a plurality of mechanical jacks that expand and contract by meshing with the gears are installed in the excavation hole. Using the jack holding member provided with an upward hook and a downward hook so as to face the hook, the downward hook is hooked on the liner plate, and the feed base on which the table moves by the rotation of the feed screw to the upward hook is attached to the table. It is fitted to the liner plate by fitting it so that the moving direction is arranged horizontally and attaching the mechanical jack to the table. The steel columns are arranged substantially vertically by pressing the steel columns placed on the pile heads by the respective mechanical jacks from the respective directions at equal angular intervals around the column axis of the steel columns. The vertical degree of the steel column is adjusted by extending or contracting one of the mechanical jacks. Furthermore, the present invention optionally forms a region of the excavation hole in which the legs of the steel column are disposed as a space having a rectangular shape in plan view having four inner wall surfaces, A plate-like liner plate is installed in each, and then the downward hook of the jack holding member is hooked on the circumferential flange portion at the uppermost stage of the liner plate, and then the upper hook of the jack holding member is fed to the upward hook. After fitting the table , by attaching the mechanical jacks to the table of the feed table, a total of four mechanical jacks, so that each expansion and contraction direction is horizontal and facing the axis center of the steel column, If the expansion and contraction direction of the mechanical jack is deviated from the axial center of the steel column after being arranged at the same depth at an angular interval of 90 degrees around the column axis, the feed screw is rotated. The horizontal position of the mechanical jack is adjusted, and the steel column placed on the pile head is pressed from four directions orthogonal to each other by each of the four mechanical jacks to support the steel column substantially vertically. In addition, the perpendicularity of the steel column may be adjusted by extending or contracting any of the four mechanical jacks.

  ADVANTAGE OF THE INVENTION According to this invention, the support and erection adjustment (re-distortion) of the steel column erected on the pile head of a cast-in-place pile can be performed more accurately in a compact work space than before, and work can be performed quickly. And shortening the construction period.

  The present invention uses a drilling hole constructed in cast-in-place pile construction and places a mechanical jack as a means for supporting and erection of steel columns in the drilling hole, so it is more compact than before. Can be adjusted (re-distortion) in a simple work space. As it is not necessary to secure a new construction space for supporting steel columns and adjusting the construction (re-distortion), it can be used as a means for supporting and installing steel columns such as on narrow platforms or between tracks. The present invention can be applied even when a space where a wire rope can be stretched cannot be secured.

  As mentioned above, the steel columns are supported and built-in (re-distorted) using the excavation holes constructed in cast-in-place pile construction, and the number of parts used to support and adjust the steel columns This is a construction method that can be realized by using a mechanical jack that is familiar to field workers, so that the work can be speeded up, the construction period can be shortened, and the additional cost can be reduced.

  By adjusting the verticality using a mechanical jack that expands and contracts due to the meshing of the gears, it is possible to accurately adjust the installation (adjustment of the verticality). In particular, by using a mechanical jack of the same type, it becomes easy to adjust the stroke amount of each mechanical jack.

  In addition, the work that uses the space inside the hole, not the work that extends outside the hole as in the case of tensioning a wire rope, may cause problems that may impede the passage of trains and users. Absent. In addition, since the structural members of the present invention such as a mechanical jack are arranged in the excavation hole below the home surface, the temporary lid for preventing the fall into the hole has almost no step from the home surface. It is possible to arrange in a state.

It is explanatory drawing which showed typically the construction method of the steel column which is one embodiment of this invention. It is a schematic diagram around the leg part of the steel column erected on the pile head of the cast-in-place pile by applying the present invention. It is a perspective view of the jack holding member which is one Embodiment shown by FIG. 1 or FIG. It is explanatory drawing which showed typically the condition which latches the jack holding member shown in FIG. 3 with respect to a liner plate. It is explanatory drawing which showed typically the condition which attaches the feed stand of a mechanical jack with respect to the jack holding member latched by the liner plate by the method shown in FIG. It is the top view which showed typically the condition where the steel column was pressed and supported from each direction with the several mechanical jack arrange | positioned in the excavation hole.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, for a cast-in-place pile (foundation pile) formed by constructing a reverse circulation excavation (TBH) method on the platform of a railway station, a square pillar shape is formed at a predetermined built-in position on the pile head. A case where the steel column is erected will be described as an example.

  First, the ground is excavated at the position where the steel column is built on the platform. For excavation of the ground, a dedicated excavator (not shown) used for the reverse circulation excavation (TBH) method is carried on the platform. After that, the bit equipped at the tip of the reverse rod of the dedicated excavator is driven to rotate, and the ground is dug to the stable ground (support layer). The earth and sand generated at this time are sucked up to the ground surface together with the muddy water through the reverse rod from the bottom side of the excavation hole, and then the earth and sand are separated from the muddy water and discharged to the remaining soil tank. The mud after separation of the earth and sand is supplied again into the borehole through the reverse rod to fill the borehole with mud water, protect the hole wall and discharge the excavated earth and sand by mud circulation. After excavating up to the support layer, a reinforcement cage is suspended in the excavation hole, and concrete is cast to a predetermined depth to form a cast-in-place pile (foundation pile).

  FIG. 1 is an explanatory view schematically showing a method of building a steel column according to an embodiment of the present invention, and in particular, a situation where a steel column 4 is erected on a home 1 by applying the present invention. It is a schematic diagram which shows. FIG. 2 is a schematic diagram of the periphery of the legs of a steel column erected on the pile head of a cast-in-place pile by applying the present invention. In the present invention, for example, when the steel column 4 constituting the structure is vertically built at a predetermined built-in position on the pile head 3a of the cast-in-place pile 3 constructed by the cast-in-place pile method as described above. It can be applied.

  In the present invention, a plurality of mechanical jacks 10 that expand and contract by meshing gears are used as a means for supporting the steel column 4 that is a heavy object and for performing adjustment (redistortion). These mechanical jacks 10 are disposed in the excavation hole 2 that is formed for constructing the cast-in-place pile 3 and in which the legs 4 a of the steel column 4 are disposed. As shown in FIG. 1 and FIG. 2, each mechanical jack 10 is disposed at the same depth position in the excavation hole 2 so that each expansion / contraction direction is horizontal.

  In this Embodiment, the area | region where the leg part 4a of the steel column 4 is arrange | positioned by the predetermined | prescribed depth from the home 1 surface is formed. The leg portions 4a arranged in this area are buried and fixed after the adjustment of erection (this area is referred to as a leg arrangement area 6 for convenience). In the present embodiment, the leg arrangement region 6 is formed as a quadrangular space (excavation hole) having four inner wall surfaces 7, that is, a substantially rectangular parallelepiped space. A liner plate 8 as a retaining member is attached to each of the four inner wall surfaces 7.

  The liner plate 8 is a retaining member in which a thin steel plate is corrugated so that its longitudinal section has a corrugated shape, and flanges are provided on its four sides, and a conventionally known member can be used. Bolts are provided on the flanges on each side of the liner plate 8, i.e., the circumferential flange portion 8 a disposed substantially horizontally with respect to the ground surface and the height direction flange portion 8 b disposed substantially perpendicular to the ground surface. A hole 8c is provided, and a retaining wall can be formed in a predetermined region by fastening adjacent liner plates to each other by bolting. When the liner plate 8 is attached, a predetermined depth position (for example, the thickness of the temporary lid 20 is about 5 cm, for example) is preferably avoided so that the circumferential flange portion 8b of the uppermost liner plate 8 does not protrude on the home surface. If so, it is preferable to install at a depth of about 5 cm from the home surface. Thereby, the temporary lid 20 covering the opening of the excavation hole 2 can be arranged in a state where there is almost no step between the surface of the temporary lid 20 and the surface of the home 1. In order to close the gap between the back side of the liner plate 8 and the inner wall surface 7 of the excavation hole, backfilling (not shown) with excavated earth or mortar is performed. The liner plate 8 can support earth pressure and water pressure from the ground around the excavation hole 2, and can prevent the ground from collapsing in the excavation hole 2.

  The jack holding member 15 can be used as a means for attaching the mechanical jack 10 to the liner plate 8 as the earth retaining member. FIG. 3 is a perspective view of the jack holding member 15 according to one embodiment shown in FIG. 1 or FIG. The jack holding member 15 includes a flat plate-like main body portion 16 that comes into contact with the liner plate 8, a hook-shaped downward hook 17 that is hooked on the liner plate 8, and a hook-shaped upward direction to which the mechanical jack 10 or the feed base 12 is attached. And a hook 18. The main body portion 16 is a portion that abuts against the inner side surface of the liner plate 8 when disposed in the excavation hole 2. The downward hooks 17 are provided as a pair on the side of the main body 16 that contacts the inner surface of the liner plate so that the tip of the hook faces downward. Further, the upward hook 18 is a steel frame when the jack holding member 15 is attached to the inside of the excavation hole 2 so that the tip of the hook faces upward. A pair is provided on the side facing the column 4. In the present embodiment, a position adjusting member 19 is provided between the main body portion 16 and the upward hook 18. In consideration of the distance between the steel column 4 and the liner plate 8 and the maximum stroke amount of the mechanical jack, the position adjusting member 19 places the mechanical jack at a position where the steel column 4 can be pressed. It is provided arbitrarily with respect to the main-body part 16 so that it can do (refer FIGS. 2-5).

  The jack holding member 15 having the configuration as shown in FIG. 3 can form the main body portion 16 by cutting a plate-shaped steel plate into a predetermined size, for example, and can form angle steel. The downward hook 17 and the upward hook 18 can be formed by cutting to a size and welding to the main body portion 16, and by cutting the grooved steel (channel steel) to a predetermined size and welding to the main body portion 16. The position adjustment member 19 can be formed. That is, since it can be manufactured by a member that normally exists at a construction site, the generation of additional costs such as procurement of new parts can be suppressed. In the case shown in FIG. 3, the numbers of the downward hooks 17 and the upward hooks 18 are one set each, but are not limited thereto. The downward hook 17 can be selected in an arbitrary size and number optimal for hanging on the liner plate, and the number of the upward hook 18 is arbitrary in size optimal for stably holding the mechanical jack in the horizontal direction. And the number can be selected.

  In the present embodiment, a jack feed base 12 that is conventionally used is mounted on the bottom of the mechanical jack body 11 (see FIG. 2). The feed base 12 includes a base 12a, a feed screw 13 supported by the base 12a, and a table 14 (slide table) on which a mechanical jack is detachably mounted. ) Is attached to the end of the feed screw 13 and the feed screw 13 is rotated, whereby the table 14 can be moved (slid) by a predetermined amount in the screw shaft direction.

  FIG. 4 is an explanatory view schematically showing a situation where the jack holding member is hooked on the liner plate shown in FIG. 3, and FIG. 5 is a diagram showing the jack holding member hooked on the liner plate by the method shown in FIG. On the other hand, it is explanatory drawing which showed typically the condition which attaches the feed stand of a mechanical jack. As shown in FIG. 4, the jack holding member 15 has the tip of the downward hook 17 between the inner wall surface 7 and the liner plate back side with respect to the upper circumferential flange portion 8 a of the uppermost liner plate 8. By being inserted from the upper side, it is hung on the liner plate 8. In addition, in order to make it easy to insert the tip of the downward hook, it is preferable to remove in advance the backfilling mortar or the like of the portion into which the downward hook 17 is inserted. Next, as shown in FIG. 5, the feed base 12 is attached to the upward hook 18 of the jack holding member 15 hooked on the liner plate 8 from above. By mounting the mechanical jack 10 on the table 14 of the feed base 12, the mechanical jack 10 can be horizontally attached to and held on the liner plate 8 installed on the inner wall surface 7 of the excavation hole 2. It can be done.

  Since the feed base 12 is attached to the upward hook 18 so that the moving direction of the table 14 is arranged substantially horizontally, the mechanical jack 10 is moved by inserting the operation rod and rotating the feed screw 13. It can be adjusted and moved by a predetermined amount in the axial direction of the feed screw, that is, in the horizontal direction. When the jack holding member 15 is hooked, the expansion / contraction direction of the mechanical jack 10 is such that the axis center of the steel column 2 arranged at a predetermined built-in position on the pile head 3a (that is, the column axis of the steel column 4 is It is desirable to be hung at a place that faces the center position. However, the expansion / contraction direction of the mechanical jack 10 may be shifted in the horizontal direction from the axial center of the steel column. In such a case, the horizontal position of the mechanical jack 10 can be adjusted by the feed base 12 so that the expansion / contraction direction faces the axis center of the steel column. Thereby, when pressing a steel column with a mechanical jack, the core of a column can be held down and the steel column 4 can be supported firmly.

  FIG. 6 is a plan view schematically showing a situation in which a steel column is pressed and supported from each direction by a plurality of mechanical jacks arranged in the excavation hole. In the present embodiment, as schematically shown in FIG. 6, the leg portion arrangement region 6 is formed as a quadrangular excavation hole having four inner wall surfaces 7, and each inner wall surface 7. A plate-like liner plate 8 is attached to the. The corner angle between the adjacent inner wall surfaces 7 is substantially a right angle, and the adjacent liner plates are fastened to each other by bolting.

  A plate-like liner plate 8 is installed as a retaining member for each of the four inner wall surfaces 7, and then the jack holding member 15 is hooked downward on the circumferential flange portion 8 a at the uppermost stage of the liner plate 8. Hang 17 Next, after the feed base 12 is fitted and attached to the upward hook 18 of the jack holding member 15, the mechanical jacks 10 are attached to the feed base 12, so that a total of four mechanical jacks 10 are attached to the steel column 4. An angular interval of 90 degrees around the column axis of the steel column 4 so as to face the axis center, that is, the center position through which the column axis of the steel column 4 passes (the position indicated by the intersection of the dashed line in FIG. 6). (That is, in directions of azimuth angles of 0 degrees, 90 degrees, 180 degrees, and 270 degrees). In addition, each mechanical jack 10 has a horizontal direction of expansion and contraction, and is disposed at the same depth in the excavation hole 2 (see FIGS. 1 and 2). Thereby, the steel column 10 is supported substantially vertically by applying a pressing force in the horizontal direction from four directions (four directions) orthogonal to each other toward the axial center of the steel column 10. All the mechanical jacks 10 are arranged in the same depth position in the excavation hole 2, that is, on the same plane orthogonal to the column axis, so that when the pressing force is applied to the steel column, Avoid generating moment force in the vertical direction. As the mechanical jack 10, it is preferable to use the same type because the same stroke is obtained with the same amount of rotation and the adjustment is easy.

  After the mechanical jacks 10 have been disposed in the excavation holes 4, after confirming that the distance between the mechanical jacks 10 is such that the base plate of the steel column 4 can pass through, the steel column 4 is used by using a heavy machine such as a crane. Is suspended on the pile head 3a, an operator enters the leg portion arrangement region 6, and a nut is attached to the anchor bolt 5 to temporarily fix the steel column 4. Each of the mechanical jacks 10 can be expanded and contracted in a direction toward the steel column 4 and a direction away from the steel column 4 by a rotation operation using a ratchet handle (not shown). The field worker operates each mechanical jack 10 and presses the steel column 4 evenly from each direction (four directions orthogonal to each other in this embodiment) through the batten 21 to thereby form the steel frame. Support column 4 to be independent. Since the main body 16 of the jack holding member 15 is disposed in contact with the earth retaining member 8 that receives the earth pressure and water pressure of the ground, the reaction force due to earth pressure and water pressure against the inclination of the steel column 4 Can be used to strongly support the steel column 4, to exert a strong reaction force against the falling of the steel column 4, and to prevent the falling.

  The perpendicularity of the steel column 4 made independent by such a method is measured by a generally used method using a transit or a level, and when an inclination exceeding an allowable value is measured, the mechanical jack 10 By rotating any one of them to expand and contract, fine adjustment is made so that the perpendicularity of the steel column 4 falls within an allowable range. The mechanical jack 10 that expands and contracts by the meshing of the gears is different from the hydraulic jack or the air jack, and can be easily expanded and contracted by the amount of rotation thereof, and can be finely adjusted in units of 1 mm. Since it has the feature that the stroke does not decrease, it is suitable as a means for supporting and erection of steel columns. In addition, when actually adjusting the installation, the jacking down operation is performed on one mechanical jack to weaken the pressing force, and then the jacking up operation is performed on the other mechanical jack to apply the pressing force. It is preferable to prevent excessive pressure from acting on the steel column. When the adjustment amount is large, the vertical degree is gradually adjusted by repeating the operation of loosening one mechanical jack and pushing it with the other mechanical jack.

  During the above operation, a temporary lid 20 that covers the opening of the excavation hole can be installed in order to prevent a passenger from falling into the excavation hole 2. Since the structural members of the present invention such as the mechanical jack 10, the jack holding member 15 and the liner plate 8 are disposed in the excavation hole 2 below the home surface, a temporary lid for preventing the fall into the excavation hole 2 is provided. 20 can be arranged flush with the home surface without a step. The receiving portion of the temporary lid 20 may be the circumferential flange portion 8a at the upper end of the liner plate 8 or the jack holding member 15. However, as shown in FIG. 2, the notch formed by notching the opening edge of the excavation hole 2 An angle steel 9 for preventing collapse may be disposed on the portion 2a, and the temporary lid 20 may be disposed on the angle steel 9.

  In the above-described embodiment, the case where the feed base 12 is used has been described as an example. However, as another embodiment, the bottom portion of the jack body 11 is directly connected to the upward hook of the jack holding member without using the feed base. You may make it attach a mechanical jack with respect to the earth retaining member installed in the excavation hole by attaching. For example, an upward hook is formed in accordance with the shape of the bottom of the mechanical jack, and the bottom of the mechanical jack is fitted into the upward hook and attached, so that it is mechanical with respect to the earth retaining member installed in the excavation hole. A jack can be attached so that a mechanical jack can be placed in the borehole. When the feed base 12 is used, the horizontal position of the mechanical jack 10 is adjusted by rotating the feed screw 13. However, the jack holding member 15 is not limited to the circumferential direction (horizontal direction) of the liner plate 8. Since it can be latched at the position, the horizontal mounting position of the mechanical jack 10 can be adjusted by adjusting the latching position with respect to the liner plate 8.

  In the above-described embodiment, the case where the steel liner plate is used as the retaining member installed in the excavation hole 2 has been described as an example, but the retaining member is a plywood for concrete formwork. The present invention can also be applied to the above. Moreover, as a mechanical jack, a screw jack, a rack drive jack, etc. can be used. Further, in the above embodiment, the case where the steel column 4 is a quadrangular column has been described as an example. However, when the steel column is a cylinder, the present invention is realized by using a curved contact plate such as a curved plywood. Is possible. Further, in the above embodiment, the case where the leg arrangement area 6 is a square space in plan view having four borehole inner walls 7 has been described as an example, but the leg arrangement area is excavated in a circular shape in plan view. When the hole is formed as a substantially cylindrical space, a jack holding member having a shape corresponding to an arc-shaped liner plate installed on the inner wall surface of the excavation hole (for example, a main body portion of the jack holding member) A jack holding member having a cross-sectional arc shape corresponding to the curved shape of the inner peripheral wall surface is used to place the mechanical jack in the excavation hole. Can do.

  In the above-described embodiment, the case where a total of four mechanical jacks are used has been described as an example. However, the number of mechanical jacks that are arranged to support the steel column substantially vertically and adjust the verticality is not limited to this, and the total number of angular jacks around the column axis (axis center) of the steel column is the same. N mechanical jacks may be arranged, and a pressing force in the horizontal direction from the N direction may be applied toward the axis center of the steel column. For example, a total of two mechanical jacks are arranged around a column axis (axial center) of a steel column at an angular interval of 180 degrees (that is, in directions of azimuth angles of 0 degrees and 180 degrees) and pressed from two directions. In this case, a total of six mechanical jacks are arranged and pressed from six directions at an angular interval of 60 degrees (ie, in directions of azimuth angles of 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees). If there are a total of eight mechanical jacks at 45 degree angular intervals (ie, azimuth angles of 0, 45, 90, 135, 180, 225, 270, and 315 degrees) For example, the case of pressing from eight directions can be considered.

  The scope of application of the present invention is not limited to steel columns that constitute railway-related structures such as station buildings and overpasses, but can be placed on the pile heads of cast-in-place piles at various construction sites where cast-in-place pile construction is performed. It can be applied to a steel column.

DESCRIPTION OF SYMBOLS 1 Platform of railroad station 2 Drilling hole 2a Notch 3 Cast-in-place pile 3a Pile head 4 (Steel cast-in pile) 4 Steel column 4a (Steel column) leg 5 Anchor bolt 6 Leg arrangement area 7 Inner wall 8 Liner plate 8a (flange plate) circumferential flange portion 8b (liner plate) height direction flange portion 8c (liner plate) bolt hole 9 angle steel 10 mechanical jack 11 mechanical jack body 12 feed base 12a base 13 feed screw DESCRIPTION OF SYMBOLS 14 Table 15 Jack holding member 16 Main-body part (Jack holding member) 17 Downward hook 18 Upward hook 19 Position adjustment member 20 Temporary cover 21 Batting wood

Claims (2)

It is a construction method of a steel column erected on the pile head of a cast-in-place pile,
Of the excavation hole formed to construct the cast-in-place pile and where the steel column legs are arranged , a liner plate is installed on the inner wall surface of the cast-in-place pile,
In the excavation hole, a plurality of mechanical jacks that expand and contract by meshing the gears are provided with jack holding members provided with an upward hook and a downward hook so that each expansion / contraction direction is horizontal and faces the axial center of the steel column. Using the downward hook on the liner plate, a feed base on which the table moves by rotating the feed screw is fitted to the upward hook so that the moving direction of the table is horizontally arranged, and the mechanical jack is By mounting on the table, it is attached to the liner plate and arranged at the same depth at equal angular intervals around the column axis of the steel column,
After supporting the steel column substantially vertically by pressing the steel column arranged on the pile head by each of the mechanical jacks from each direction,
A method of erection of a steel column, characterized in that the verticality of the steel column is adjusted by extending or contracting one of the mechanical jacks. A region in which the legs of the steel column are arranged in the excavation hole is formed as a rectangular space in plan view having four inner wall surfaces,
A plate-like liner plate is installed on each of the four inner wall surfaces, and then a downward hook of the jack holding member is hooked on a circumferential flange portion at the uppermost stage of the liner plate, and then the jack holding member After fitting the feed base into the upward hook, and attaching the mechanical jacks to the table of the feed base, a total of four mechanical jacks can be connected to each other in the horizontal direction and the axis of the steel column. After being arranged at the same depth at an angular interval of 90 degrees around the column axis so as to face the center,
When the expansion / contraction direction of the mechanical jack is deviated from the axial center of the steel column, the horizontal position of the mechanical jack is adjusted by rotating the feed screw,
By supporting the steel columns substantially vertically by pressing the steel columns arranged on the pile heads from the four directions orthogonal to each other by each of the four mechanical jacks,
Kenkomi method of steel columns of claim 1, wherein the adjusting the perpendicularity of the said steel columns by stretching either the four mechanical jacks.