Construction method and adjustable structure for building adjustment structures

Abstract

To absorb the cumulative shrinkage and construction errors caused by on-site welding in buildings, and to reduce the labor involved. [Solution] The adjustment structure 10 includes a gusset plate 15 having loose holes 17. The steel beam 12 includes a flange 21 and a web 20 having bolt holes. The construction method for the adjustment structure 10 includes a temporary fastening step of inserting temporary fastening bolts into the loose holes 17 and bolt holes and temporarily fastening them, and a forming step of welding the steel column 11 and the web 20 to form a welded part, and welding the steel column 11 and the flange 21 to form a welded part 25.

Description

Technical Field

[0001] The present disclosure relates to a construction method for an adjustment structure of a building and an adjustment structure.

Background Art

[0002] In large-scale buildings, there are concerns about the accumulation of shrinkage caused by on-site welding and the accumulation of construction errors in steel frame erection. For example, Patent Document 1 describes a joining method in which a clearance is provided between a concrete-filled steel column and the side surface of the column to form a girder, and the clearance side of the girder is joined with a bolt, so that the girder can be joined without adjusting the length due to construction errors between columns.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in the above-described joining method, it is necessary to fill the clearance with cement to join the concrete-filled steel column and the girder, which requires a great deal of labor.

Means for Solving the Problem

[0005] This disclosure provides a construction method for an adjustable structure for a building that solves the above problems. The construction method for an adjustable structure for a building is a construction method for an adjustable structure for a building using a steel structural member and a steel beam, wherein the steel structural member is provided with a gusset plate having loose holes, and the steel beam is provided with a flange and a web having bolt holes, the opening area of ​​the loose holes being larger than the opening area of ​​the bolt holes, and the method includes a temporary fastening step of inserting temporary fastening bolts into the loose holes and the bolt holes for temporary fastening, and a forming step of welding the steel structural member and the web to form a first welded joint, and welding the steel structural member and the flange to form a second welded joint.

[0006] This disclosure provides an adjustable structure for a building that solves the above problems. The adjustable structure for a building comprises a steel structural member and a steel beam having a flange and a web having bolt holes, and further comprises a gusset plate provided on the steel structural member and having a loose hole whose opening area is larger than the opening area of ​​the bolt holes, a first welded joint to which the steel structural member and the web are welded, and a second welded joint to which the steel structural member and the flange are welded. [Effects of the Invention]

[0007] According to this disclosure, it is possible to absorb the accumulation of shrinkage and construction errors caused by on-site welding in buildings, and to reduce the effort involved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of an adjustment structure according to one embodiment of the present disclosure. [Figure 2] This is a top view of the adjustment structure according to the same embodiment. [Figure 3] This is an enlarged cross-sectional view along line AA in Figure 1. [Figure 4] This is a plan view showing a region of a building equipped with the adjustment structure according to the same embodiment. [Figure 5] This is a plan view showing another area of ​​a building equipped with the adjustment structure according to the same embodiment. [Modes for carrying out the invention]

[0009] The following describes the construction method of the building adjustment structure and one embodiment of the adjustment structure described herein. [Adjustment structure] As shown in Figures 1 to 3, the building adjustment structure 10 according to one embodiment of the present disclosure is provided at the joint between the steel column (steel structural member) 11 and the steel beam 12 which is a main beam.

[0010] The steel column 11 is equipped with a gusset plate 15 having loose holes 17. The steel column 11 is made of a rectangular steel pipe and has a joint steel pipe 11A located at the joint with the steel beam 12. Through diaphragms 13 are provided at the upper and lower ends of the joint steel pipe 11A. The gusset plate 15 is attached to the side surface 14 of the steel column 11 to which the steel beam 12 is joined. The gusset plate 15 is a rectangular plate. The longitudinal ends 16 of the gusset plate 15 are pre-welded to the side surface 14 of the steel column 11 at the factory.

[0011] The gusset plate 15 has four loose holes 17 arranged in a row along the longitudinal direction of the gusset plate 15. The loose holes 17 are elongated holes, and their longitudinal direction is parallel to the longitudinal direction of the steel beam 12. Temporary fastening bolts 18 (see Figure 2) are inserted into the loose holes 17. The temporary fastening bolts 18 are, for example, high-strength bolts. The opening area of ​​the loose holes 17 is larger than the opening area of ​​the bolt holes 32, which will be described later. The length of the loose holes 17 in the short direction is the sum of the bolt diameter of the temporary fastening bolt 18 and a predetermined clearance determined according to the bolt diameter. The length of the loose holes 17 in the longitudinal direction is the sum of the bolt diameter and clearance, plus an adjustment allowance A. The temporary fastening bolts 18 may be removed after the welded joint 40, which will be described later, is formed. For the sake of explanation, the temporary fastening bolts 18 are omitted in Figure 1.

[0012] The steel beam 12 is made of H-shaped steel and comprises a flange 21 and a web 20 having bolt holes 32. The groove 23 of the flange 21 is machined to be oblique and straight. The groove 23 of the flange 21 and the through diaphragm 13 are butt-welded to form a welded joint 25. Scallops 24 are formed at the upper and lower ends of the longitudinal end of the web 20.

[0013] Figure 3 is a cross-sectional view along line AA in Figure 1, showing the state in which a temporary fastening bolt 18 is installed in the bolt hole 32. The web 20 has a groove 31 that is machined at an angle and in a straight line. The bolt hole 32 is a round hole, and its diameter is the sum of the bolt diameter of the temporary fastening bolt 18 and a predetermined clearance corresponding to the bolt diameter.

[0014] The adjustment structure 10 includes a welded joint 40 (first welded joint) to which the steel column 11 and the web 20 are welded, and a welded joint 25 (second welded joint) to which the steel column 11 and the flange 21 are welded. The gusset plate 15 is fillet-welded to the steel column 11 on the side 26 opposite to the web 20. This forms a welded joint 28. The gusset plate 15 has a groove 29 formed by partial penetration welding on the side surface 27 that is in contact with the web 20. The groove 29 is welded to the side surface 14 of the steel column 11 to form a welded joint 30. The welded joint 30 is smoothed with a grinder so as not to interfere with the welded joint 40 of the web 20. The welded joints 28 and 30 are pre-formed in the factory.

[0015] Due to the accumulation of shrinkage caused by on-site welding and construction errors, the web 20 may have its groove 31 misaligned from the designed position relative to the steel column 11. The loose hole 17 absorbs this misalignment with adjustment allowance A. With the misalignment absorbed by the loose hole 17, temporary fastening bolts 18 are inserted into the loose hole 17 and the bolt hole 32. Nuts 35 are fastened to the temporary fastening bolts 18 via washers 33 and 34.

[0016] In a state where it is temporarily tightened by the temporary tightening bolt 18, the groove 31 of the web 20 is joined to the steel column 11 by butt welding with complete penetration. During welding, the gusset plate 15 serves as a backing material. By forming the welded portion 40 between the groove 31 and the steel column 11, the steel column 11 and the steel beam 12 are integrally joined.

[0017] Arrangement of Adjustment Structure Fig. 4 is a plan view showing one region of a building provided with the adjustment structure 10 according to the present embodiment. The building 50 includes a plurality of steel beams 12A, a plurality of steel beams 12B, and a plurality of adjustment structures 10A and 10B as the adjustment structure 10. The width direction of the building 50 (W direction in the figure) is parallel to the longitudinal direction of the steel beams 12A. The depth direction of the building 50 (D direction in the figure) is parallel to the longitudinal direction of the steel beams 12B. The steel beams 12A are sequentially joined to the steel columns 11 along the erection escape direction 100, which is the direction in which the steel columns 11 and the steel beams 12 are assembled. The steel beams 12B are sequentially joined to the steel columns 11 along the erection escape direction 101.

[0018] The adjustment structures 10A are provided on the steel beams 12A, and absorb shrinkage caused by on-site welding and construction errors that accumulate when each of the steel beams 12A is joined to the steel column 11. The adjustment structure 10A is provided at one end on one side of the steel beam 12A. As shown in Fig. 4, when the adjustment structure 10A is provided at one location on one side of one steel beam 12A, the adjustment allowance A corresponding to the accumulated shrinkage caused by on-site welding and accumulated construction errors is secured at that one location. Note that the adjustment structure 10A may be provided at two locations at both ends of one steel beam 12A. In this case, the adjustment allowance A corresponding to the accumulated shrinkage caused by on-site welding and accumulated construction errors is secured at two locations. The adjustment structure 10B is the same as the adjustment structure 10A except that it is provided on the steel beam 12B.

[0019] Fig. 5 is a plan view showing another region of a building provided with the adjustment structure 10 according to the present embodiment, and shows one construction block 51 among the plurality of construction blocks of the building 50. In Fig. 5, each side of one grid represents one span (column spacing), and the steel columns 11 and steel beams 12 are omitted from illustration for convenience.

[0020] Welding of the steel column 11 and the steel beam 12 is sequentially performed in the construction block 51 along the erection advance directions 100, 101 from the construction block boundary 52 toward the outer peripheral portion 53 of the building 50. Adjacent construction blocks (not shown) are sequentially welded along the erection advance directions 102, 103 from the construction block boundary 52. Shrinkage due to on-site welding and construction errors in steel frame erection accumulate in the erection advance directions 100 to 103.

[0021] The construction block 51 is provided with unadjusted spans S1 where the adjustment structure 10 is not provided, and adjusted spans S2 where the adjustment structure 10 is provided on the steel beam 12. The adjusted spans S2 are provided at adjustment positions B of the construction block 51. Similarly, unadjusted spans S1 and adjusted spans S2 are also provided in other construction blocks (not shown). In Fig. 5, the positions of the respective adjusted spans S2 are indicated by double lines. In the following description, when the unadjusted span S1 and the adjusted span S2 are not distinguished, they are simply referred to as span S.

[0022] The adjusted spans S2 are provided along the vicinity of the outer peripheral portion 53 of the building 50 to ensure the accuracy of the outer wall (not shown). That is, the adjusted spans S2 are arranged along the outer wall of the building 50 in the width direction W and the depth direction D of the building 50. In the example of Fig. 5, the construction block 51 is provided with 8 rows and 15 columns of spans S. The adjusted span S2 provided with the adjustment structure 10A is provided one span inward from the outer peripheral portion 53 parallel to the depth direction D. The adjusted span S2 provided with the adjustment structure 10B is provided one span inward from the outer peripheral portion 53 parallel to the width direction.

[0023] Further, the adjusted spans S2 are provided at intervals of several spans according to the adjustment allowance A. For example, one adjusted span S2 is provided every seven spans in the width direction W and the depth direction D of the building 50. Thereby, the adjusted span S2 is provided at the adjustment position B between the construction block boundary 52 and the outer peripheral portion 53. For other construction blocks not shown, adjusted spans S2 are similarly provided in consideration of the construction block boundary 52 and the erection advance directions 100 to 103.

[0024] The adjustment allowance A for the loose hole 17 will be explained. The adjustment allowance A is set taking into account the cumulative shrinkage due to on-site welding and the cumulative construction errors in steel frame erection. In on-site welding, if there is a possibility of shrinkage of "1 mm" per joint, and since there are two joints on both sides of the steel beam 12, the predicted shrinkage per span will be "2 mm". Therefore, if "N" is the number of spans for which the adjustment structure 10 absorbs the cumulative shrinkage due to on-site welding and the cumulative construction errors, then "the cumulative welding shrinkage δ = 2 mm × N". For example, in the example in Figure 5, in the width direction W and depth direction D of the building 50, the adjustment position B is spaced at intervals of 7 spans, so "the cumulative welding shrinkage δ = 14 mm".

[0025] The adjustment allowance A is determined according to the accumulated welding shrinkage amount δ and the adjustment structure 10. It is preferable that the adjustment allowance A of the loose hole 17 be equal to or greater than the accumulated welding shrinkage amount δ. If the adjustment structure 10 is provided on both sides of the steel beam 12, not just one side, it is preferable that the adjustment allowance A of the loose hole 17 be equal to or greater than half of the accumulated welding shrinkage amount δ.

[0026] [Construction method for adjustable structures] Next, a construction method for an adjustment structure according to one embodiment of the present disclosure will be described. The construction method for the adjustment structure is the construction method for the adjustment structure 10 described above, and includes a temporary fastening step and a forming step. Referring again to Figures 1 to 3 and Figure 5, in this construction method, in the work section 51, in the area of ​​the non-adjustable span S1, welding of the steel columns 11 and steel beams 12 is performed along the vertical relief directions 100 and 101. Then, when the area of ​​the adjustment span S2 at a specified position is reached, the temporary fastening step and the forming step are performed at the position where the adjustment structure 10 is to be installed among the steel beams 12 of the adjustment span S2.

[0027] In the temporary fastening process, the gusset plate 15 and web 20 are positioned, and temporary fastening bolts 18 are inserted into the loose holes 17 and bolt holes 32 to perform temporary fastening. In the forming process, the webs 20 of the steel column 11 and steel beam 12 are butted together and welded to complete penetration to form a welded joint (first welded joint) 40. At this time, the gusset plate 15 can also be used as a backing material. In addition, the flanges 21 of the steel column 11 and steel beam 12 are welded together in a butt position to form a welded joint (second welded joint) 25. After the adjustment structure 10 is formed, the temporary fastening bolts 18 may be removed. After the preliminary tightening and forming processes are completed, welding is performed on the joint of the non-adjustable span S1 located on the outer circumference 53 side of the adjustable span S2 in the vertical relief direction 100, 101.

[0028] [effect] As described above, the following effects can be obtained according to the above embodiment. (1) The cumulative shrinkage due to on-site welding and the cumulative construction errors in steel frame erection can be absorbed by the adjustment allowance A of the loose holes 17. Then, after absorbing the cumulative shrinkage due to on-site welding and the cumulative construction errors, the steel column 11 and the steel beam 12 are welded together as a single unit. This absorbs the cumulative shrinkage due to on-site welding and the cumulative construction errors in the building 50, and also reduces the amount of work involved. Furthermore, since the side surface 14 of the steel column 11 and the groove 31 of the web 20 of the steel beam 12 are joined together by the welded joint 40, the joint strength of the joint structure can be increased.

[0029] (2) The gusset plate 15 provided on the steel column 11 and having loose holes 17 can also be used as a backing material when welding on site. (3) An adjustment structure 10 can be provided in the outer perimeter 53 of the building 50, where the cumulative amount of shrinkage due to on-site welding and the cumulative amount of construction errors in steel frame erection tend to be large.

[0030] (4) By providing adjustment spans S2 at a specified number of spans S, in addition to positions along the outer perimeter 53 of the building 50, problems caused by the accumulation of shrinkage due to on-site welding and construction errors can be eliminated at each adjustment position B of the building 50.

[0031] [Example of changes] The above embodiment can be implemented with the following modifications. The embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. The steel structural members are not limited to steel columns, but can be any structural members made of steel, such as rigidly connected beams. Also, the steel column 11 may be made of other steel structural members such as H-beams, rather than square steel pipes. Furthermore, the steel column 11 may be provided with an internal diaphragm instead of a through diaphragm. If an internal diaphragm is provided, the steel beam 12 is welded to the side surface 14 of the steel column 11.

[0032] The gusset plate 15 may be welded to the steel column 11 on-site rather than being welded in the factory. In other words, the welded joints 28 and 30 may be formed on-site. The gusset plate 15 may be joined to the steel column 11 by high-strength bolts.

[0033] The adjustment structure 10 may be provided at the joints between the main beams and secondary beams, which are steel structural members. In the above embodiment, four loose holes 17 are formed in the gusset plate 15, but the number of loose holes 17 is not limited to four as shown in the figure, and there may be multiple holes.

[0034] In the above embodiment, the adjustment span S2 is provided along the vicinity of the outer perimeter 53 of the building 50, but the position of the adjustment span S2 is not particularly limited and can be set according to the structure of the building 50. In the above embodiment, the adjustment span S2 is provided one span inward from the outer perimeter 53 of the building 50, but the invention is not limited to this, and for example, the adjustment span S2 may be provided in the row or column of the outermost spans S of the work section 51. [Explanation of Symbols]

[0035] S...Span, S1...Non-adjustable span, S2...Adjustable span, 10, 10A, 10B...Adjustable structure, 11...Steel column (steel structural material), 12, 12A, 12B...Steel beam, 15...Gusset plate, 17...Loose hole, A...Adjustment allowance for loose hole, B...Adjustment position, 18...Temporary fastening bolt, 20...Web, 21...Flange, 25...Welded joint (second weld), 26, 28, 30...Weld, 40...Welded joint (first weld), 32...Bolt hole, 50...Building, 51...Work section, 52...Work section boundary, 53...Outer perimeter.

Claims

1. A construction method for a building adjustment structure using steel structural materials and steel beams, The aforementioned steel structural member includes a gusset plate having a loose hole, The steel beam comprises a flange and a web having bolt holes, The opening area of ​​the loose hole is larger than the opening area of ​​the bolt hole. A temporary tightening step involves inserting temporary tightening bolts into the loose holes and bolt holes and temporarily tightening them, A method for constructing an adjustable structure for a building, comprising the steps of forming a first weld by welding the steel structural material and the web, and forming a second weld by welding the steel structural material and the flange.

2. The method for constructing an adjustable structure for a building according to claim 1, wherein the gusset plate is used as a backing material in the forming step.

3. A method for constructing an adjustment structure for a building according to claim 1, wherein after welding of steel structural members and steel beams in predetermined spans provided in the construction section of the building, the adjustment structure is installed along the vicinity of the outer perimeter of the building.

4. A method for constructing an adjustment structure for a building according to claim 3, wherein the adjustment structure is provided every few spans.

5. A building adjustment structure comprising a steel structural member and a steel beam having a flange and a web with bolt holes, A gusset plate provided in the steel structural member, having a loose hole whose opening area is larger than the opening area of ​​the bolt hole, The first welded joint to which the steel structural member and the web are welded, A building adjustment structure comprising the aforementioned steel structural material and a second welded joint to which the flange is welded.

Images