Steel frame construction method

Abstract

We provide a steel frame construction method that contributes to the leveling of construction labor. [Solution] When constructing a roof steel frame 10 having a configuration in which multiple first steel beams arranged in parallel intersect with multiple second steel beams arranged in parallel, the first steel beams are designed so that the vertical load acting on the roof steel frame 10 can be supported by only the first steel beams until construction of the roof steel frame 10 is completed, and the roof steel frame 10 is constructed sequentially along construction direction A corresponding to the parallel direction of the first steel beams while being supported by supports 81 at the top of the bents 8. During construction of the roof steel frame 10, the constructed roof steel frame 10 is jacked down using jacks on supports 81 in a first range 10-1, which is a predetermined length range along construction direction A from the start of construction direction A, and then the constructed roof steel frame 10 is jacked down using jacks on supports 81 in a second range 10-2 adjacent to first range 10-1 in construction direction A.

Description

[Technical Field]

[0001] The present invention relates to a method for constructing a steel frame structure. [Background technology]

[0002] The ceiling of an arena structure is often constructed with a steel roof frame (steel frame structure) such as a truss beam to support roofing materials such as a folded-plate roof. When installing the steel roof frame, for example, the roof frame is installed while being supported by the support part at the top of the vent, and then the vent is removed by jacking down using a jack attached to the support part.

[0003] Patent Document 1 describes a method in which a vent is installed in an open-ceiling space, the steel frame of the truss frame is erected while the truss frame is supported by a jack at the top of the vent, and then the jack is lowered to release the support of the truss frame from the vent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-096163 Summary of the Invention [Problem to be solved by the invention]

[0005] Two-way trusses are known as a type of steel roof structure. This structure uses truss beams arranged in two intersecting directions to transmit the vertical load acting on the steel roof in two directions, improving support performance and allowing the cross-section of the truss beams to be smaller.

[0006] However, in the case of a two-way truss, a frame capable of supporting vertical loads cannot be established until the installation of the truss beams on both sides is complete. Therefore, in order to jack down the roof steel frame and release the support provided by the vents, it is necessary to complete the installation of the roof steel frame in both directions, i.e., to complete the installation of the entire roof steel frame, and then jack down the entire roof steel frame.

[0007] Jacking down causes the roof steel frame to displace (sink), so subsequent processes such as laying roofing materials are carried out after jacking down. However, if the entire roof steel frame is jacked down after the entire roof steel frame has been installed, subsequent processes such as laying roofing materials cannot be carried out until the entire roof steel frame has been jacked down, even in areas where the roof steel frame has been installed initially. As a result, for those areas, there will be a long wait before subsequent processes can be carried out. From the perspective of leveling out construction labor (mountain collapse) as much as possible, there is room for consideration of such wait times.

[0008] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a steel frame construction method and the like that contributes to the leveling of construction labor. [Means for solving the problem]

[0009] To solve the above problems 1st The invention is a construction method for constructing a steel frame structure having a configuration in which a plurality of first steel beams arranged in parallel cross a plurality of second steel beams arranged in parallel, wherein the first steel beams are designed so that a vertical load acting on the steel frame structure can be supported by only the first steel beams until construction of the steel frame structure is completed, and when constructing the steel frame structure, the steel frame structure is supported by a support part at the top of a bent, and the steel frame structure is constructed in order along a construction direction corresponding to the parallel direction of the first steel beams, and during construction of the steel frame structure, the constructed steel frame structure is jacked down using jacks attached to the support parts in a first range which is a range of a predetermined length along the construction direction from the start point of the construction direction, and then Without moving the steel frame structure in the first range in a plane,This is a steel frame construction method characterized in that the constructed steel frame is jacked down using jacks attached to the support parts in a second range adjacent to the first range in the construction direction. A second invention is a construction method for constructing a steel frame structure having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, wherein the first steel beams are designed so that a vertical load acting on the steel frame structure can be supported by only the first steel beams until construction of the steel frame structure is completed, and when constructing the steel frame structure, the steel frame structure is supported by a support part at the top of a bent, and the steel frame structure is constructed in order along a construction direction corresponding to the parallel direction of the first steel beams, and during construction of the steel frame structure, the constructed steel frame structure is jacked down in a first range, which is a range of a predetermined length along the construction direction from the start point of the construction direction, by jacks provided on the support parts, and then, in a second range adjacent to the first range in the construction direction, the constructed steel frame structure is jacked down in a second range adjacent to the first range in the construction direction. This is a construction method for a steel frame, characterized in that the steel frame is jacked down using a jack attached to the support, the first and second steel beams are truss beams, the upper chord of the second steel beam is arranged to connect the upper chords of adjacent first steel beams, the lower chord of the second steel beam is arranged to connect the lower chords of adjacent first steel beams, and the diagonal member of the second steel beam is arranged between the upper chord and the lower chord of the second steel beam, and when jacking down the steel frame in the first range, in the area of ​​the second range on the first range side, one end of the diagonal member is fixed to one of the upper chord and the lower chord of the second steel beam, and the other end of the diagonal member is capable of moving relatively to the other of the upper chord and the lower chord of the second steel beam. A third invention is a construction method for constructing a steel frame structure having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, wherein the first steel beams are designed so that a vertical load acting on the steel frame structure can be supported by only the first steel beams until the construction of the steel frame structure is completed, and when constructing the steel frame structure, the steel frame structure is constructed in order along a construction direction corresponding to the parallel direction of the first steel beams while being supported by a support part at the top of a bent, and during the construction of the steel frame structure, the constructed steel frame structure is jacked down in a first range, which is a range of a predetermined length from the start point of the construction direction along the construction direction, by jacks provided on the support parts, and then, a second steel beam that is adjacent to the first steel beam and has been constructed, and jacks down the constructed steel beam using jacks attached to the support parts; the first and second steel beams are truss beams, the upper chords of the second steel beams are arranged to connect the upper chords of the adjacent first steel beams, the lower chords of the second steel beams are arranged to connect the lower chords of the adjacent first steel beams, and the diagonal members of the second steel beams are arranged between the upper chords and the lower chords of the second steel beams; and when jacking down the steel beam in the first range, the lower chords of the second steel beams are made displaceable relative to the lower chords or the diagonal members of the adjacent first steel beams in the area of ​​the second range on the first range side. A fourth invention is a construction method for constructing a steel frame structure having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, wherein the first steel beams are designed so that a vertical load acting on the steel frame structure can be supported by only the first steel beams until the construction of the steel frame structure is completed, and when constructing the steel frame structure, the steel frame structure is constructed in order along a construction direction corresponding to the parallel direction of the first steel beams while being supported by a support part at the top of a bent, and during the construction of the steel frame structure, the constructed steel frame structure is jacked down in a first range, which is a range of a predetermined length along the construction direction from the start point of the construction direction, by jacks provided on the support parts, and then, a second steel beam that is adjacent to the first steel beam and has been constructed, and jacks down the constructed steel beam using jacks attached to the supports; the first and second steel beams are truss beams, the upper chords of the second steel beams are arranged to connect the upper chords of adjacent first steel beams, the lower chords of the second steel beams are arranged to connect the lower chords of adjacent first steel beams, and the diagonal members of the second steel beams are arranged between the upper chords and the lower chords of the second steel beams; and when jacking down the steel beam in the first range, the upper chords of the second steel beams are made displaceable relative to the upper chords or the diagonal members of the adjacent first steel beams in the area of ​​the second range on the first range side.

[0010] In this invention, the steel beams are designed so that the vertical load acting on the steel frame can be supported by only the steel beams in one direction out of the two intersecting steel beams. Then, during construction of the steel frame, the steel frame is constructed along the construction direction, which is the direction in which the steel beams are lined up, and during construction, the constructed steel frame is jacked down in a first range, which is a predetermined length range along the construction direction from the start point of the construction direction. This allows subsequent processes, such as laying roofing materials, to be carried out early in the first range, thereby facilitating the process (leveling out construction labor).

[0011] before As mentioned above, when the steel frame in the first range is jacked down, a slight displacement occurs in the steel frame in the first range. This causes excessive stress to be generated in the diagonal members and their joints of the second steel beam (truss beam) in the area adjacent to the first range, which may cause breakage. There is also a risk of excessive reaction force being generated in the vent. 2nd to 4th In the invention, the above-mentioned area is used as a buffer zone, and the occurrence of the above-mentioned stresses and reaction forces is prevented by leaving either end of the diagonal member, or part of the upper chord member and lower chord member free.

[0012] After jacking down the steel frame structure in the first range, it is desirable to start roofing work to lay roofing material on top of the steel frame structure in the first range before completing construction of the steel frame structure in the second range. As described above, in the present invention, by jacking down the steel frame structure in the first range early, roof construction work on the first range can be started early, making it possible to complete the construction process.

[0013] After jacking down the steel frame structure in the first range, it is desirable to remove the vent that was supporting the steel frame structure in the first range, and start interior construction or equipment construction work in the space below the roof material before completing construction of the steel frame structure in the second range. By completing the roof work in the first range early as described above, interior and equipment work in the space below the roofing material can also begin early, making it possible to streamline the process. [Effects of the Invention]

[0014] The present invention can provide a steel frame construction method that contributes to the leveling of construction labor. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing an outline of an arena structure 1. FIG. [Figure 2] FIG. 2 is a diagram showing the plan view of the roof steel frame 10. [Figure 3] A diagram explaining steel beams 4 and 5. [Figure 4] FIG. 10 is a partial view showing steel beams 4 arranged in parallel. [Figure 5] 10A to 10C are diagrams illustrating the construction procedure for the roof steel frame 10. [Figure 6] A diagram explaining jacking up and jacking down. [Figure 7] 10A to 10C are diagrams illustrating the construction procedure for the roof steel frame 10. [Figure 8] A diagram showing the diagonal member 53 of buffer zone a. [Figure 9] An example of joint material 521. [Figure 10] 10A to 10C are diagrams illustrating the construction procedure for the roof steel frame 10. [Figure 11] A diagram showing a schematic example in which parts of the diagonal member 53, lower chord member 52, and upper chord member 51 are allowed to move relative to each other. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0017] FIG. 1 is a diagram showing an outline of an arena structure 1 to which a steel roof frame 10 is constructed by a construction method according to an embodiment of the present invention.

[0018] The arena structure 1 has seating 2 surrounding a column-free arena space S, with a roof steel frame 10 spanning the perimeter steel frame 3 installed around the seating 2, and a roof material 7 such as a folded-plate roof supported by the roof steel frame 10. The roof steel frame 10 is a steel frame that forms the ceiling of the arena structure 1, and various types of equipment (not shown) are also installed in the ceiling. The equipment includes ducts, cable racks, distribution boards, lighting, etc., but is not particularly limited to these.

[0019] FIG. 2 is a diagram showing a plan view of the roof steel frame 10 of the arena structure 1 with part of the roof material 7 omitted.

[0020] As shown in Figure 2, the roof steel frame 10 has steel beams 4 and 5 and diagonal members 6. The arena structure 1 has a roughly elliptical plan, and the steel beams 4 are arranged in the direction of the short sides of the plan. The steel beams 5 are arranged in the direction of the long sides of the plan of the arena structure 1. Note that Figure 1 shows the arena structure 1 along the short side direction of the plan of the arena structure 1, i.e., along the span direction of the steel beams 4.

[0021] In the arena structure 1, multiple steel beams 4 (first steel beams) are arranged in parallel, and similarly multiple steel beams 5 (second steel beams) are arranged in parallel. These steel beams 4, 5 intersect in a plane. In the example of Figure 2, the steel beams 4, 5 intersect at right angles. The diagonal member 6 is arranged diagonally to the steel beams 4, 5 in a plane.

[0022] FIG. 3(a) is a diagram showing a schematic diagram of how steel beams 4 and 5 are combined, and FIGS. 3(b) and 3(c) are diagrams showing the schematic configurations of steel beams 4 and 5, respectively.

[0023] The steel beam 4 is a truss beam having an upper chord 41, a lower chord 42, diagonal members 43, and struts 44, and is formed from steel materials such as H-shaped steel. The diagonal members 43 are arranged diagonally to the vertical direction between the upper chord 41 and the lower chord 42, and the struts 44 are arranged vertically between the upper chord 41 and the lower chord 42. Multiple struts 44 are arranged at intervals in the span direction of the steel beam 4. The diagonal members 43 are arranged between adjacent struts 44 in the span direction, and both ends of the diagonal member 43 are fixed to the upper chord 41 and the lower chord 42 of the steel beam 4 at the same positions as the struts 44 on either side of the diagonal member 43.

[0024] The steel beam 5 is also a truss beam having an upper chord 51, a lower chord 52, a diagonal member 53, and a beam 54. The upper chord 51, the lower chord 52, the diagonal member 53, and the beam 54 are similar to the upper chord 41, the lower chord 42, the diagonal member 43, and the beam 44 of the steel beam 4.

[0025] In the roof steel frame 10, the steel beams 4 and 5 are combined so that the post 44 of the steel beam 4 and the post 54 of the steel beam 5 are the same member. In other words, one vertical member is used as the post 44, 54 of both steel beams 4 and 5. However, there are also cases where the post 44 of the steel beam 4 and the post 54 of the steel beam 5 are separate members.

[0026] FIG. 4 is a diagram partially illustrating steel beams 4 arranged in parallel. As shown in FIG. 4, adjacent steel beams 4 in the direction in which the steel beams 4 are lined up, i.e., the parallel direction of the steel beams 4, are connected by the upper chord members 51 and lower chord members 52 of the steel beams 5. The upper chord members 51 connect the upper chord members 41 of both steel beams 4 at positions where they abut the upper ends of the struts 44 (54), and the lower chord members 52 connect the lower chord members 42 of both steel beams 4 at positions where they abut the lower ends of the struts 44 (54). The diagonal members 6 are arranged between adjacent upper chord members 51 in the span direction of the steel beams 4, at an angle to the upper chord members 41, 51. Both ends of the diagonal member 6 are fixed to the upper chord members 41 of the adjacent steel beams 4 at the same positions as the adjacent upper chord members 51 on both sides.

[0027] Construction of the roof steel frame 10 begins after construction of at least the perimeter steel frame 3 and before construction of the roof material 7. The roof steel frame 10 is constructed in sections in the span direction of the steel beams 4, with an end 4-1 on the perimeter steel frame 3 side and a central section 4-2 between both end sections 4-1 (see Figure 2). Construction of the roof steel frame 10 is carried out in order from its starting point to its terminal end, with the parallel direction of the steel beams 4 serving as the construction direction. The construction direction of the roof steel frame 10 corresponds to the up-down direction in Figure 2. The starting point of the construction direction is, for example, the upper end of the roof steel frame 10 in Figure 2, and the terminal end of the construction direction is the opposite end.

[0028] As shown in Figure 5(a), a temporary vent 8 is erected in the arena space S, and a support part 81 is provided at the top of the vent. The steel beam 4 at the end part 4-1 is installed with one end on the central part 4-2 side (corresponding to the left side of Figure 5(a)) supported by the support part 81 and the other end joined to the outer periphery steel frame 3.

[0029] As shown in Fig. 6(a), support by the support part 81 is achieved by supporting a support member 813 provided on the underside of the steel beam 4 with a girder support bracket 812 provided on the top of the bent 8. Reference numeral 811 in Fig. 6(a) denotes a jack that will be used in a later process.

[0030] Next, the new steel beam 4 that has been assembled in the yard on the ground (inside the arena space S) is lifted by a crane (not shown) and installed next to the previously erected steel beam 4 in the same manner as described above, as shown in Figure 5(b).

[0031] After the new steel beam 4 has been assembled and installed in this manner, as shown in Figure 5(c), the previously erected steel beam 4 and the new steel beam 4 (hereinafter referred to as the subsequent steel beam 4) are connected by the upper chord 51 and lower chord 52 of the steel beam 5 as described above, and diagonal members 53, 6, etc. are installed. Equipment (not shown) in the ceiling of the arena structure 1 can be installed between the previously erected steel beam 4 and the subsequent steel beam 4 during the process of installing the upper chord 51, lower chord 52, diagonal members 53, 6, etc.

[0032] In this embodiment, next, as shown in Fig. 5(d), a new steel beam 4 is installed next to the following steel beam 4 in the same manner as in Fig. 5(b). Hereafter, the following steel beam 4 is read as the previously erected steel beam 4, and the steps of Fig. 5(c) and (d) are repeated.

[0033] The steel beams 4, 5, etc. in the central section 4-2 can be constructed in the same manner. However, since both ends of the steel beam 4 in the central section 4-2 in the span direction can be joined to the steel beams 4 at both ends 4-1 with bolts or the like, there is no particular need for bents 8, etc. to support the steel beam 4 in the central section 4-2.

[0034] As described above, by installing the steel beams 4 at both ends 4-1 and the steel beams 4 at the center 4-2, as well as the upper chord members 51, lower chord members 52, diagonal members 53, etc. of the steel beams 5, the construction of the roof steel frame 10 proceeds along the construction direction, as shown by arrow A in Figure 7. Figure 7 is a view of the roof steel frame 10 in the middle of construction, viewed along the construction direction A. Construction direction A corresponds to the long side direction of the arena structure 1, i.e., the span direction of the steel beams 5.

[0035] The basic method for constructing the roof steel frame 10 is as described above, but in this embodiment, the (maximum) vertical load acting on the roof steel frame 10 at least until the entire construction of the roof steel frame 10 is completed is estimated in advance, and the steel beams 4 are designed so that this vertical load can be supported by the steel beams 4 alone. The vertical load is, for example, the sum of the weight of the roof steel frame 10 itself and the weight of accessories to the roof steel frame 10 (equipment, ceiling panels, roof underlayment, temporary materials, etc., not shown). Simply put, the steel beams 4 are designed so that these weights can be supported even without the upper chords 51, lower chords 52, diagonal members 53, and diagonal members 6 of the steel beams 5. For this reason, the cross-sections of the constituent members of the steel beams 4 are usually larger than those of the two-way truss described above.

[0036] Although the upper chord 51, lower chord 52, diagonal members 53, etc. of the steel beams 5 have the effect of dispersing and supporting vertical loads, these effects are not exerted, or even if they are exerted, they can be supported by the steel beams 4 without taking this into consideration, and when the roof steel frame 10 is constructed, the frame is formed by the steel beams 4 alone. Therefore, the upper chord 51, lower chord 52, diagonal members 53, etc. of the steel beams 5 can be installed at any time, not just the above-mentioned times, and after construction of the roof steel frame 10 is completed, redundancy is ensured by the steel beams 5 in terms of supporting vertical loads.

[0037] In this embodiment, during construction of the roof steel frame 10, the constructed roof steel frame 10 is jacked down in a first range 10-1, which is a range of a predetermined length along the construction direction A from the starting point in the construction direction A (the right end in FIG. 7). Jacking down is performed by extending the jack 811 as shown in FIG. 6(b) from a state in which the steel beams 4 are supported by the girder support fittings 812, transferring the load of the steel beams 4 from the girder support fittings 812 to the jack 811, and then gradually retracting the jack 811 while removing the girder support fittings 812 from the top, as shown in FIG. 6(c). After jacking down, the vents 8 and associated supports 81, etc. are removed.

[0038] When the roof steel frame 10 is jacked down, a slight displacement (sinking) occurs in the first region 10-1 of the roof steel frame 10. As a result, a downward load W (see FIG. 7) is applied to the installed roof steel frame 10 in the second region 10-2 adjacent to the first region 10-1 in the installation direction A of the roof steel frame 10. This load W may cause excessive stress to be generated in the diagonal members 53 and their joints in the area a on the first region 10-1 side of the second region 10-2, resulting in breakage or the like. There is also a risk of excessive reaction force being generated in the vent 8.

[0039] Therefore, in this embodiment, this region a is used as a buffer zone for displacement during jacking down, and measures are taken to prevent excessive stress from occurring in the diagonal members 53 and their joints, or excessive reaction force from occurring in the vents 8, when the roof steel frame 10 in the first range 10-1 is jacked down.

[0040] 8(a) is a diagram showing a diagonal member 53 of buffer zone a. In this example, the diagonal member 53 is placed between a connecting member 511 provided on an upper chord member 51 and a connecting member 521 provided on a lower chord member 52. H-shaped steel is used for the diagonal member 53 and the connecting members 511 and 521.

[0041] 8(b) is an enlarged view of the upper end of the diagonal member 53. The upper end of the diagonal member 53 and the connecting member 511 are joined using splice plates 55 and 57 and fasteners 56 and 58 made of bolts and nuts. This fixes the upper end (one end) of the diagonal member 53 to the upper chord member 51.

[0042] 8(b), splice plates 55 are placed on both sides of the flanges of the upper end of the diagonal member 53 and the connecting member 511 so as to straddle these flanges, and the flange of the upper end of the diagonal member 53 and the splice plates 55 on both sides thereof are fastened (temporarily fastened) using fasteners 56. In addition, the flange of the connecting member 511 and the splice plates 55 on both sides thereof are temporarily fastened using fasteners 56.

[0043] Similarly, splice plates 57 are placed on both sides of the webs of the upper end of the diagonal member 53 and the connecting member 511 so as to straddle these webs, and the web at the upper end of the diagonal member 53 and the splice plates 57 on both sides thereof are temporarily fastened together using fasteners 58. In addition, the web of the connecting member 511 and the splice plates 57 on both sides thereof are temporarily fastened together using fasteners 58.

[0044] In contrast, the lower end (the other end) of the diagonal member 53 is in a state in which it can be displaced relative to the lower chord member 52 during jacking down.

[0045] Fig. 8(c) is an enlarged view of the lower end of the diagonal member 53. In the example of Fig. 8(c), splice plates 55 are arranged on both sides of the flanges of the lower end of the diagonal member 53 and the joining material 521 so as to straddle these flanges, but the flange of the lower end of the diagonal member 53 and the splice plates 55 on both sides thereof are only fastened (temporarily fastened) using fasteners 56, and the flange of the joining material 521 is merely sandwiched between the splice plates 55 on both sides thereof.

[0046] Similarly, splice plates 57 are arranged on both sides of the web so as to span the lower end of the diagonal member 53 and the connecting material 521, but the web at the lower end of the diagonal member 53 and the splice plates 57 on both sides are only fastened (temporarily fastened) using fasteners 58, and the web of the connecting material 521 is simply sandwiched between the splice plates 57 on both sides.

[0047] By allowing the lower end of the diagonal member 53 to be displaced relative to the lower chord 52 in this way, it is possible to prevent the load W during jacking down from causing excessive stress on the diagonal member 53 and its joints, or from causing excessive reaction force in the bent 8. Conversely to the above, it is also possible to fix the lower end of the diagonal member 53 to the lower chord 52 and allow the upper end of the diagonal member 53 to be displaced relative to the upper chord 51. The load W is transmitted to the second range 10-2 side via the upper chord 51 and lower chord 52 of the buffer zone a, and is supported by the bent 8 and other elements provided in the second range 10-2.

[0048] Note that not only H-shaped steel but also channel steel and angle steel can be used for the diagonal members 53 and the connecting members 511 and 521. FIG. 9(a) shows an example in which a channel steel is used for the connecting member 521. The bottom surface of the connecting member 521, which has a concave cross section, is fastened with a bolt 523 to a plate member 522 fixed to a lower chord member 52 or the like. FIG. 9(b) shows a cross section taken along line AA in FIG. 9(a). The connecting members 521 are arranged back-to-back on both sides of the plate member 522, and the bolt 523 is inserted from one of the connecting members 521. The shaft of the bolt 523 penetrates the plate member 522 and the connecting members 521 on both sides of it, and a nut 524 is fastened to the tip of the shaft protruding from the other connecting member 521.

[0049] Returning to the explanation of Figure 7, construction of the roof steel frame 10 in the second area 10-2 continues even while the roof steel frame 10 in the first area 10-1 is being jacked down. After the roof steel frame 10 is jacked down in the first area 10-1, as shown in Figure 10, roof construction begins on top of the roof steel frame 10 to lay roofing material 7, such as a folded-plate roof. When the roofing material 7 is laid, a watertight line formed by the roofing material 7 is formed on the vertical cross section of the arena structure 1. Furthermore, the vent 8 has been removed in the first area 10-1, allowing the use of a large space to directly lift materials and equipment to the required floors with a crane. This eliminates the need for temporary elevators or other post-construction areas, and allows interior construction and facility construction of the arena space S to begin without rework below the roofing material 7.

[0050] After the construction of the roof steel frame 10 in the second section 10-2 is completed, the roof steel frame 10 in the second section 10-2 is jacked down. After jacking down, the fasteners 56, 58 (see Figure 8) are tightened in the buffer zone a. The flange of the connecting member 521 is fastened to the splice plates 55 on both sides of the flange using fasteners, and the web of the connecting member 521 is fastened to the splice plates 57 on both sides of the web using fasteners, thereby fixing the lower end of the diagonal member 53 to the bottom chord 52. These splice plates 55, 57 can be replaced depending on the relative positions of the connecting member 521 and the lower end of the diagonal member 53 after jacking down. The vents 8 and other components are then removed, completing the construction of the entire roof steel frame 10. The roof construction, interior construction, and equipment construction work described above continue in the second section 10-2.

[0051] As explained above, in this embodiment, the steel beams 4 are designed so that, of the two intersecting steel beams 4, 5, only the steel beams 4 in one direction can support the vertical load acting on the roof steel frame 10. Then, when constructing the roof steel frame 10, construction of the roof steel frame 10 proceeds along construction direction A, which is the direction in which the steel beams 4 are lined up, and during construction, the constructed roof steel frame 10 is jacked down in a first range 10-1, which is a range of a predetermined length along construction direction A from the start of construction direction A. This allows for early start of roof construction work for laying the roof material 7, interior construction work for the arena space S below the roof material 7, equipment construction, and the like, in the first range 10-1, thereby facilitating the smooth construction process (leveling out construction labor).

[0052] When the roof steel frame 10 in the first area 10-1 is jacked down, some displacement occurs in the roof steel frame 10 in the first area 10-1. As a result, excessive stress is generated in the diagonal members 53 of the steel beams 5 and their joints in the area a on the first area 10-1 side of the second area 10-2 that follows the first area 10-1, which may result in breakage or other problems. There is also a risk of excessive reaction force being generated in the vent 8. Therefore, in this embodiment, the above-mentioned area a is used as a buffer zone, and one end of the diagonal member 53 is left free, thereby preventing the generation of the above-mentioned stress and reaction force.

[0053] However, the present invention is not limited to the above embodiment. For example, in this embodiment, the roof steel frame 10 of the arena structure 1 is divided into three in the span direction of the steel beams 4, but the number of divisions is arbitrary and may be increased or decreased depending on the situation. Also, in this embodiment, the steel beams 4 are beams in the short side direction of the arena structure 1, but they may also be beams in the long side direction of the arena structure 1 (steel beams 5 are beams in the short side direction).

[0054] The planar shape of the arena structure 1 is not particularly limited, and may be a circle (a perfect circle) or a polygon such as a rectangle. In either case, the steel beams 4, 5 are arranged in two intersecting directions on the planar surface. In this embodiment, the steel beams 4, 5 are truss beams, but the structure of the steel beams 4, 5 is not particularly limited. The positions of the vents 8, etc. can also be determined in various ways depending on the arrangement of the steel beams 4, etc.

[0055] In this embodiment, roof construction is carried out after the roof steel frame 10 is jacked down, but if the displacement (settlement) of the roof steel frame 10 during jacking down is small enough to prevent buckling of the roof material 7, such as a folded-plate roof, it is possible to carry out roof construction before jacking down the roof steel frame 10, allowing roof construction to begin earlier.In addition, interior construction and equipment construction for the arena space S can also be started earlier.

[0056] Furthermore, in this embodiment, as shown in FIG. 11(a), the lower ends of the diagonal members 53 of the buffer zone a are displaceable relative to the bottom chord 52 when the first section 10-1 of the roof steel frame 10 is jacked down, and are fixed to the bottom chord 52 after the second section 10-2 of the roof steel frame 10 is jacked down. However, as shown in FIG. 11(b), the diagonal members 53 may not be provided when the first section 10-1 of the roof steel frame 10 is jacked down, and the diagonal members 53 may be placed and fixed at both ends after the second section 10-2 of the roof steel frame 10 is jacked down. However, inserting the diagonal members 53 into the roof steel frame 10 of the buffer zone a in a later process requires some effort. The diagonal members 53 are fixed using splice plates 55, 57 and fasteners 56, 58, but they can also be fixed by welding or other methods.

[0057] When jacking down the steel roof frame 10 in the first section 10-1, as shown in FIG. 11(c), both ends of the bottom chord 52 in the buffer zone a may be displaceable relative to the adjacent bottom chords 42, etc., or as shown in FIG. 11(d), the middle portion of the bottom chord 52 in the buffer zone a may be displaceable relative to the diagonal members 53, etc. Which portion of the bottom chord 52 is free can be determined based on the plan for the temporary scaffolding (not shown), etc. The bottom chord 52 is fixed to the adjacent bottom chords 42, etc. or diagonal members 53, etc., after jacking down the steel roof frame 10 in the second section 10-2. Alternatively, as shown in FIG. 11(e), the bottom chord 52 may not be provided when jacking down the steel roof frame 10 in the first section 10-1, but may be placed after jacking down the steel roof frame 10 in the second section 10-2 and fixed to the adjacent bottom chords 42, etc. or diagonal members 53, etc., on both sides.

[0058] Furthermore, as shown in FIG. 11(f), when the roof steel frame 10 in the first range 10-1 is jacked down, both ends of the upper chord member 51 in the buffer zone a may be made movable relative to the adjacent upper chord members 41, etc. Also, as shown in FIG. 11(g), the middle portion of the upper chord member 51 in the buffer zone a may be made movable relative to the diagonal members 53, etc. The upper chord member 51 is fixed to the adjacent upper chord members 41, etc. or diagonal members 53, etc. on both sides after the roof steel frame 10 in the second range 10-2 is jacked down. Alternatively, as shown in FIG. 11(h), similar to the above, the upper chord member 51 may not be provided when the roof steel frame 10 in the first range 10-1 is jacked down, and the upper chord member 51 may be placed after the roof steel frame 10 in the second range 10-2 is jacked down and fixed to the adjacent upper chord members 41, etc. or diagonal members 53, etc. on both sides. However, in these cases, roof construction work on the second area 10-2 must begin after the upper chord 51 is fixed.

[0059] Furthermore, the steel frame structure in this embodiment is the roof steel frame 10 of the ceiling of the arena structure 1, but the present invention is not limited to the arena structure 1 and can be applied to any construction of the ceiling of a structure with a large space, such as a large logistics facility, stadium, gymnasium, exhibition hall, airport, etc. Furthermore, the steel frame structure is not limited to the roof steel frame 10 that supports the roof material 7, and may be a frame that supports floor material, for example.

[0060] In addition, in this embodiment, the steel frame structure is jacked down in two separate steps, but it is also possible to jack down the steel frame structure in three or more separate steps using the same procedure.

[0061] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications or alterations within the scope of the technical ideas disclosed herein, and it is understood that these modifications also fall within the technical scope of the present invention. [Explanation of symbols]

[0062] 1: Arena Structures 4, 5: Steel beams 7: Roofing materials 8: Vent 10: Steel roof frame 41, 51: Top chord material 42, 52: Lower chord 43, 53: Diagonal material 44, 54: Bundle material 811: Jack

Claims

1. A construction method for constructing a steel frame having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, The first steel beam is designed so that a vertical load acting on the steel frame can be supported by the first steel beam alone until construction of the steel frame is completed, When constructing the steel frame, While supporting the steel frame by the support portion at the top of the bent, the steel frame is constructed in sequence along a construction direction corresponding to the parallel direction of the first steel beams, During construction of the steel frame structure, jacking down the constructed steel frame structure is performed using jacks provided on the support parts in a first range that is a range of a predetermined length along the construction direction from the start end of the construction direction, Thereafter, without moving the steel frame structure in the first range in a plane, the constructed steel frame structure is jacked down in a second range adjacent to the first range in the construction direction using jacks provided on the support parts.

2. A construction method for constructing a steel frame having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, The first steel beam is designed so that a vertical load acting on the steel frame can be supported by the first steel beam alone until construction of the steel frame is completed, When constructing the steel frame, While supporting the steel frame by the support portion at the top of the bent, the steel frame is constructed in sequence along a construction direction corresponding to the parallel direction of the first steel beams, During construction of the steel frame structure, jacking down the constructed steel frame structure is performed using jacks provided on the support parts in a first range that is a range of a predetermined length along the construction direction from the start end of the construction direction, Then, in a second range adjacent to the first range in the construction direction, the constructed steel frame is jacked down by a jack provided on the support portion, the first and second steel beams are truss beams, The upper chord members of the second steel beams are provided to connect the upper chord members of the adjacent first steel beams to each other, The lower chord members of the second steel beams are provided to connect the lower chord members of the adjacent first steel beams to each other, The diagonal member of the second steel beam is provided between the upper chord member and the lower chord member of the second steel beam, A construction method for a steel frame structure, characterized in that when jacking down the steel frame structure in the first range, in the area of ​​the second range on the first range side, one end of the diagonal member is fixed to one of the upper chord and the lower chord of the second steel beam, and the other end of the diagonal member is capable of relative displacement to the other of the upper chord and the lower chord of the second steel beam.

3. A construction method for constructing a steel frame having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, The first steel beam is designed so that a vertical load acting on the steel frame can be supported by the first steel beam alone until construction of the steel frame is completed, When constructing the steel frame, While supporting the steel frame by the support portion at the top of the bent, the steel frame is constructed in sequence along a construction direction corresponding to the parallel direction of the first steel beams, During construction of the steel frame structure, jacking down the constructed steel frame structure is performed using jacks provided on the support parts in a first range that is a range of a predetermined length along the construction direction from the start end of the construction direction, Then, in a second range adjacent to the first range in the construction direction, the constructed steel frame is jacked down by a jack provided on the support portion, the first and second steel beams are truss beams, The upper chord members of the second steel beams are provided to connect the upper chord members of the adjacent first steel beams to each other, The lower chord members of the second steel beams are provided to connect the lower chord members of the adjacent first steel beams to each other, The diagonal member of the second steel beam is provided between the upper chord member and the lower chord member of the second steel beam, A construction method for a steel frame structure, characterized in that when jacking down the steel frame structure in the first range, the lower chord of the second steel beam in the area on the first range side of the second range is made capable of relative displacement with respect to the lower chords or diagonal members of the first steel beams on either side.

4. A construction method for constructing a steel frame having a configuration in which a plurality of first steel beams arranged in parallel and a plurality of second steel beams arranged in parallel intersect, The first steel beam is designed so that a vertical load acting on the steel frame can be supported by the first steel beam alone until construction of the steel frame is completed, When constructing the steel frame, While supporting the steel frame by the support portion at the top of the bent, the steel frame is constructed in sequence along a construction direction corresponding to the parallel direction of the first steel beams, During construction of the steel frame structure, jacking down the constructed steel frame structure is performed using jacks provided on the support parts in a first range that is a range of a predetermined length along the construction direction from the start end of the construction direction, Then, in a second range adjacent to the first range in the construction direction, the constructed steel frame is jacked down by a jack provided on the support portion, the first and second steel beams are truss beams, The upper chord members of the second steel beams are provided to connect the upper chord members of the adjacent first steel beams to each other, The lower chord members of the second steel beams are provided to connect the lower chord members of the adjacent first steel beams to each other, The diagonal member of the second steel beam is provided between the upper chord member and the lower chord member of the second steel beam, A construction method for a steel frame structure, characterized in that when jacking down the steel frame structure in the first range, the upper chord of the second steel beam is made capable of relative displacement in the area of ​​the second range on the first range side relative to the upper chord or diagonal of the first steel beam on either side.

5. After jacking down the steel frame structure in the first range, before construction of the steel frame structure in the second range is completed, 2. The steel frame construction method according to claim 1, further comprising the step of starting roof construction work for laying roofing material on the steel frame in the first range.

6. After jacking down the steel frame structure in the first range, the vent that supported the steel frame structure in the first range is removed; A steel frame construction method according to claim 5, characterized in that interior construction or equipment construction of the space below the roof material is started below the roof material before construction of the steel frame structure in the second range is completed.

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