Shell steel pipe column base structure with root-wrapped concrete and its construction method

Abstract

To provide a column base structure which does not require an expensive tapered pipe when erecting columns with different diameters and can sufficiently reduce the labor required for construction. [Solution] The column base structure 1 according to the present invention comprises an upper diaphragm 11 which is a through diaphragm above the joint section Jo, an outer shell steel pipe 12 which is positioned above the upper diaphragm 11 and is installed so as to form a poured concrete space 14 inside by the upper diaphragm 11 and the upper floor steel column Pu, and a temporary fixing means 13 for temporarily fixing the upper floor steel column Pu to the outer shell steel pipe 12.

Description

[Technical Field]

[0001] The present invention relates to a column base structure for erecting columns with different diameters, and a column base construction method using the same. [Background technology]

[0002] In the past, tapered pipes were commonly used as a connecting means to ensure structural continuity between columns on the upper and lower floors in structures with different column diameters. These tapered pipes are used as connecting materials to smoothly connect a large-diameter column on the lower floor to a small-diameter column on the upper floor. Tapered pipe-based connection methods often eliminate the need for separate concrete linings because they ensure structural continuity. However, in logistics warehouses and other facilities, concrete is commonly used to protect the columns from contact with forklifts and other vehicles. While a construction method that does not use tapered pipes involves encasing the bases of small-diameter columns in concrete linings to integrate the components, this method presents challenges, such as complex stress transfer path design and difficulty in ensuring structural continuity. Another column base structure that reduces construction time is one that consists of a base material fixed to the side of the column, a panel that completely covers the side of the column, and a base fixed below the column and panel (see Patent Document 1). However, in the former case, there were problems such as the high cost of tapered pipes and the time-consuming process of welding during production. In addition, even in the latter case, joints had to be installed on the side of the columns and temporary supports had to be installed on-site to stabilize the columns. In other words, there was a problem that the construction work could not be reduced sufficiently. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-45611 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of these problems, the present invention aims to provide a column base structure that does not require expensive tapered pipes when erecting columns of different diameters and that can significantly reduce the amount of construction work required. [Means for solving the problem]

[0005] The column base structure method of the present invention is a column base structure for an upper floor steel column when installing an upper floor steel column that is thinner than a lower floor steel column on an upper floor, and the column base structure is installed above a joint portion that joins a column and a beam using a through diaphragm. This structure has the following elements: Upper diaphragm: A through diaphragm placed at the top of the joint. Outer shell steel pipe: Located above the upper diaphragm, this steel pipe is the same size as the steel pipe at the joint, and forms a space inside where concrete is poured. This space is surrounded by the outer shell steel pipe, the steel columns on the upper floor, and the upper diaphragm. Temporary fixing means: A component used to temporarily fix the steel columns on the upper floor to the outer steel pipes. It serves to stabilize the columns during construction, and also functions as a structural component to transmit the axial force of the columns to the outer steel pipes after concrete is poured. As a result, the bases of the upper floor columns can be formed structurally rationally using concrete as the base. [Effects of the Invention]

[0006] The column base structure of the present invention eliminates the need to use tapered pipes for column bases and joint components when erecting columns with different diameters, thereby reducing material costs. Furthermore, it also eliminates the need for on-site welding of steel columns on the upper floors, which reduces construction labor. The present invention has the effect of providing such a column base structure. With the column base structure of the present invention, when erecting steel columns for upper floors on site, the outer steel pipe structure stabilizes the columns, ensuring safety against the steel columns for upper floors tipping over during erection. This also has the effect of providing a column base structure that allows safe erection without the need for temporary shoring. [Brief explanation of the drawings]

[0007] [Figure 1] 1A and 1B are diagrams showing an example in which the upper floor steel columns in the first embodiment are made of square steel pipes, where (a) is an oblique view (the arrow F in the diagram points to the front), (b) is a plan view, and (c) is a front view. [Figure 2] 1A and 1B are diagrams showing an example in which the upper floor steel columns in the first embodiment are H-shaped steel columns, where (a) is an oblique view (the arrow F in the diagram points to the front), (b) is a plan view, and (c) is a front view. [Figure 3] 1A and 1B are diagrams showing an example of the temporary fixing means of the first embodiment in a case where the upper floor steel column in Alternative Example 1 is a square steel pipe, where (a) is an oblique view (the direction of the arrow F in the figure is the front direction), (b) is a plan view, and (c) is a front view. [Figure 4] 1A and 1B are diagrams showing an example of the temporary fixing means of the first embodiment in a case where the upper floor steel column in Alternative Example 1 is an H-shaped steel, where (a) is an oblique view (the direction of the arrow F in the figure is the front direction), (b) is a plan view, and (c) is a front view. [Figure 5] 10A and 10B are diagrams showing an example of the temporary fixing means of the first embodiment in Alternative Example 2 in which the upper floor steel column is a square steel pipe, where (a) is an oblique view (the direction of the arrow F in the figure is the front direction), (b) is a plan view, and (c) is a front view. [Figure 6] 1A and 1B are diagrams showing an example of the temporary fixing means of the first embodiment in a case where the upper floor steel column in Alternative Example 2 is an H-shaped steel, where (a) is a perspective view (the arrow direction of F in the figure is the front direction), (b) is a plan view, and (c) is a front view. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, the column base structure according to this embodiment and a column base construction method using the same will be described with reference to the drawings. [Example]

[0009] [Basic configuration of the column base structure of this embodiment] This column base structure 1 is a column base structure set at the top of the joint section Jo where columns of different diameters are erected. The configuration is shown in Figures 1 to 6 and below. The column base structure 1 according to the first embodiment is a column base structure 1 for an upper floor steel column Pu, which is thinner than a lower floor steel column Pl, when the upper floor steel column Pu is installed on an upper floor. The column base is located above a joint Jo that joins a column and a beam using a through diaphragm. Here, the joint Jo uses a through diaphragm to connect the upper floor steel column Pu with the lower floor steel column Pl and the beam Be (or beam bracket). The joint Jo is a box-shaped steel member, and both the upper diaphragm 11 and the lower diaphragm Dl are through diaphragms. The method of connecting columns and beams using through diaphragms used in this invention uses common technology and is not part of the present invention. The column base structure 1 includes an upper diaphragm 11, an outer steel pipe 12, and temporary fixing means 13. The upper diaphragm 11 is a through diaphragm above the joint Jo. The outer shell steel pipe 12 is positioned above the upper diaphragm 11 and is installed so that the upper diaphragm 11 and the upper floor steel column Pu form a poured concrete space 14 inside. The outer shell steel pipe 12 is welded to the upper diaphragm 11, but the upper floor steel column Pu and the upper diaphragm 11 are not joined. The temporary fixing means 13 is a means for temporarily fixing the upper floor steel column Pu to the outer shell steel pipe 12. As shown in Figure 1(a) etc., the outer shell steel pipe 12 must be sized to fit the upper floor steel column Pu inside so that a poured concrete space 14 can be formed inside. The outer shell steel pipe 12 may be either square or circular. However, if the joint Jo is a square steel pipe, the outer shell steel pipe 12 must also be a square steel pipe, and if the joint Jo is a circular steel pipe, the outer shell steel pipe 12 must also be a circular steel pipe.

[0010] [Regarding temporary fixing means in the column base structure of this embodiment] The temporary fixing means 13 according to this embodiment is a means that uses a first gusset plate 131, an angle iron 132, and a first gusset connecting means 133, as shown in Figures 1 and 2. That is, it includes one or more pairs of a first gusset plate 131 set on the upper floor steel column Pu and an angle iron 132 set on the inner periphery of the outer shell steel pipe 12. It also includes a first gusset connecting means 133 for connecting the first gusset plate 131 and the angle iron 132. 1 and 2 of this embodiment, there are two sets of first gusset plates 131 and angle irons 132. However, in the present invention, there may be one or more sets, and the number of sets may be other than two depending on the stability and the shape of the outer shell steel pipe. 1 and 2 of this embodiment, a bolted joint is shown as the first gusset joint 133. However, the first gusset joint of the present invention is not limited to a bolted joint, and any other means may be used as long as the joint is easy to join and the assembly accuracy can be easily adjusted.

[0011] [Another example of temporary fixing means for column base structures] However, the temporary fixing means according to the present invention is not limited to the means using the first gusset plate, angle iron, and first gusset joining means. The means according to the following modified examples 1 and 2 are also included in the category of temporary fixing means according to the present invention. In addition, any other means may be used as long as it can temporarily fix the steel columns of the upper floor inside the outer shell steel pipes.

[0012] <Another example of temporary fixing means 1> The temporary fixing means 13 according to Modified Example 1 is a means that uses a second gusset plate 134, a third gusset plate 135, and a second gusset joining means 136, as shown in Figures 3 and 4. That is, it includes one or more pairs of a second gusset plate 134 set on the upper floor steel column Pu and a third gusset plate 135 set on the inner periphery of the outer shell steel pipe 12. It also includes a second gusset joining means 136 for joining the second gusset plate 134 and the third gusset plate 135. 3 and 4 of this embodiment, there are four pairs of second gusset plates 134 and third gusset plates 135. However, in the present invention, there may be one or more pairs, and the number of pairs may be other than four depending on the stability and the shape of the outer shell steel pipe. 3 and 4 of this embodiment, the second gusset connecting means 136 is shown as a bolt connecting means. However, the second gusset joining means of the present invention is not limited to bolt joining means, and any means may be used as long as joining is easy and the assembly precision can be easily adjusted. In the case of bolt fastening means, by making the bolt holes elongated holes, it becomes possible to adjust the angle of the pillar in the direction of gravity in the temporary fixing step described below. Furthermore, in the case of bolt connection means, it is easy to make adjustments such as providing a vertical gap of about 5 mm between the upper floor steel column Pu and the upper diaphragm 11, as will be described later. This also applies to the first embodiment shown in Figures 1 and 2.

[0013] <Another example of temporary fixing means 2> The temporary fixing means 13 according to Modified Example 2 is a means that uses guide plates 137 and lower guide portions 138 as shown in Figures 5 and 6. That is, first, it has a plurality of guide plates 137 set on the inner periphery of the outer shell steel pipe 12. The plurality of guide plates 137 are for forming temporary fixing spaces 15 into which the upper floor steel columns Pu are inserted and temporarily fixed at the upper positions of the outer shell steel pipes 12. Second, it has a lower guide portion 138 set on the upper diaphragm 11. The lower guide portion 138 is for temporarily fixing the lowest part of the upper floor steel columns Pu. Here, as shown in Figure 6, if the upper floor steel column Pu is an H-shaped steel, a cover plate 139 may be set between the flanges of the upper floor steel column Pu to enable guiding by the guide plate 137. In this embodiment, as shown in FIGS. 5 and 6, four guide plates 137 are provided on all four sides. However, in the present invention, it is sufficient to provide two or more guide plates depending on the stability and the shape of the outer shell steel pipe.

[0014] Moreover, unlike the other fixing means described above, in Alternative Example 2 it is necessary to temporarily fix the bottom of the upper floor steel column Pu for the following reason. That is, in Alternative Example 2, the guide plate 137 and the upper floor steel column Pu are only in contact with each other and are not fixed, so there is a possibility that the lowermost position of the upper floor steel column Pu may shift laterally during erection or concrete pouring. For this reason, a guide is attached to the lowermost part of the upper floor steel column Pu, and the lowermost part of the upper floor steel column Pu is temporarily fixed.

[0015] FIG. 5 shows a lower guide portion 138 in the case where the upper floor steel column Pu is made of a square steel pipe in this modified example 2. As shown in Figure 5(c), the lower guide portion 138 is substantially trapezoidal (a rectangular plate-like shape at the bottom and a trapezoidal plate-like shape at the top; hereinafter referred to as "substantially trapezoidal"). Furthermore, as shown in Figure 5(b), the lower guide portion 138 is set at an angle on the diagonal of the upper floor steel column Pu at the position where the upper floor steel column Pu should be erected on the upper diaphragm 11. In other words, the two side edges of the substantially trapezoidal rectangular portion of the lower guide portion 138 guide and temporarily fix the two opposing side edges of the upper floor steel column Pu. The size of the lower guide portion 138 is such that the upper floor steel column Pu is fitted into the lower guide portion 138 from the bottom surface of the lower part of the upper floor steel column Pu toward the interior space, so that the lowest part of the upper floor steel column Pu is temporarily fixed without any "play." The material of the lower guide portion 138 is not limited as long as it is strong enough to temporarily fix the upper floor steel column Pu.

[0016] FIG. 6 shows a lower guide portion 138 in the case where the upper floor steel column Pu is an H-shaped steel in this modification 2. As shown in Figures 6(a), 6(b), and 6(c), the lower guide portion 138 is a pair of T-shaped structures, consisting of a roughly trapezoidal plate shown in Figure 6(c) and a roughly triangular plate shown in the cross-sectional view A of Figure 6(c), which are combined at the center of the roughly trapezoid to form a T shape. The two T-shaped structures are symmetrical, vertically symmetrical in Figure 6(b), symmetrical in the depth direction in Figure 6(c), and symmetrical left and right in the cross-sectional view A of Figure 6(c), forming an H shape when viewed from above. The two sides of the roughly trapezoidal rectangular portions of the two T-shaped structures guide and temporarily fix the two flange portions of the upper floor steel column Pu. Furthermore, as shown in the cross-sectional view A of Figure 6(c), the gap between the two roughly triangular plates guides and temporarily fixes the web of the upper floor steel column Pu. The size of the lower guide portion 138 is such that the lowermost part of the upper floor steel column Pu is temporarily fixed without any "play" when the upper floor steel column Pu is fitted into the lower guide portion 138 from its lowermost part. There are no restrictions on the material of the lower guide portion 138, as long as it is strong enough to temporarily fix the upper floor steel column Pu.

[0017] However, in the present invention, the lower guide portion 138 is not limited to the shape and temporary fixing method shown in FIGS. Any shape and temporary fixing method may be used as long as it is set on the upper diaphragm 11 and is used to temporarily fix the bottom of the upper floor steel column Pu.

[0018] [Construction method of a column base using the column base structure of this embodiment] The method for constructing a column base using the column base structure 1 of this embodiment is as follows.

[0019] <Temporary fixing means setting step> This is a step of setting temporary fixing means 13 to the outer shell steel pipe 12 and the upper floor steel column Pu, or to the outer shell steel pipe 12 and the upper diaphragm 11. This step is generally performed at the factory, which reduces the amount of work required on-site.

[0020] <Diagram welding step> This is the step of welding the upper diaphragm 11 and the lower diaphragm D1 to the joint Jo to produce a beam-column joint (commonly known as a die). This step is generally performed in the factory.

[0021] <Welding step for outer steel pipes, etc.> This is the step of welding the lower floor steel column P1 and the outer shell steel pipe 12 to the column-beam joints fabricated in the above steps.

[0022] <Temporary Fixation Step> This is a step in which the upper floor steel column Pu is inserted into the outer shell steel pipe 12 and temporarily fixed vertically by the temporary fixing means 13.

[0023] When the temporary fixing means 13 is a means using the first gusset plate 131, the angle iron 132 and the first gusset joining means 133, the following applies. That is, first, the upper floor steel column Pu is inserted into the outer shell steel pipe 12. Then, the first gusset plate 131 and the angle iron 132 are joined by the first gusset joining means 133 so that the column is vertical.

[0024] When the temporary fixing means 13 is a means using the second gusset plate 134, the third gusset plate 135 and the second gusset joining means 136, the following applies. That is, first, the upper floor steel column Pu is inserted into the outer shell steel pipe 12. Then, the second gusset plate 134 and the third gusset plate 135 are joined by the second gusset joining means 136 so that the pillars are vertical. When the second gusset connection means 136 is a bolt connection means, if the bolt holes are elongated holes, it becomes possible to finely adjust the angle of the column.

[0025] In addition, if the temporary fixing means 13 uses bolt fastening, using high-strength bolts requires a special wrench, and work cannot be performed inside the outer shell steel pipe 12, so it is desirable to use medium-sized bolts.

[0026] When the temporary fixing means 13 is a means using guide plates 137, the outer shell steel pipe 12 is inserted into the temporary fixing space 15 formed by a plurality of guide plates 137 attached to the inside of the outer shell steel pipe 12. Then, simply by fitting the lowest part of the upper floor steel column Pu into the lower guide part 138, the upper floor steel column Pu is temporarily fixed vertically.

[0027] When erecting the upper floor steel columns Pu on site, the outer steel pipes 12 themselves protect and stabilize the upper floor steel columns Pu, ensuring safety against the upper floor steel columns Pu tipping over during erection. Furthermore, this makes safe erection possible without the need for temporary shoring.

[0028] Furthermore, in this temporary fixing step, it is preferable to temporarily fix the upper floor steel column Pu with a gap of about 5 mm in the vertical direction between the upper floor steel column Pu and the upper diaphragm 11. This gap makes it possible to position the upper floor steel column Pu vertically even if there is a foreign object on the upper diaphragm 11. Such a gap can be easily set, for example, when the temporary fixing means 13 is a means using the second gusset plate 134, the third gusset plate 135, and the second gusset joining means 136 joined by bolts. The above-mentioned gap is not essential to the present invention, and the gap may be eliminated.

[0029] <Concrete pouring step> This is a step in which concrete is poured into the slab of the upper floor, or separately from that, concrete is poured into the pouring concrete space 14. Pouring concrete into the pouring concrete space 14 can be carried out together with pouring the slab, thereby shortening the process and reducing the amount of work required.

[0030] [Effects of this Example] The column base structure according to this embodiment is a column base structure provided with an outer shell steel pipe and temporary fixing means. Therefore, when erecting columns with different diameters, there is no need to use tapered pipes for the column bases or joints, which reduces material costs. Also, there is no need to install joints by on-site welding for steel columns on the upper floors, which reduces construction labor. This provides the effect of being able to provide such a column base structure.

[0031] The column base structure according to this embodiment is a structure in which the story steel column can be inserted inside after the steel frame of the lower floor to which the outer shell steel pipe is attached has been erected. Therefore, when erecting the steel columns of the upper floors on site by inserting them into the outer shell steel pipes, the structure of the outer shell steel pipes stabilizes the columns, ensuring safety against the steel columns of the upper floors tipping over during erection.Furthermore, this has the effect of providing a column base structure that allows for safe erection without the need for temporary shoring. Furthermore, with the above structure, the outer steel pipes function as both formwork and reinforcing material, eliminating the need for formwork and reinforcing bar construction, which contributes to labor savings and shortened construction time. Furthermore, the above structure allows the concrete to be poured simultaneously with the slab, and the work can be carried out in an integrated manner, thereby shortening the process and reducing the amount of work required for construction.

[0032] The column base structure of this embodiment is a structure in which an outer shell steel pipe is installed on top of the upper diaphragm. This has the effect of reducing the amount of work required for on-site construction, such as welding the outer shell steel pipe onto the upper diaphragm at a location other than the site, for example, a factory.

[0033] The column base structure according to this embodiment is a column base structure including an upper diaphragm, an outer steel pipe, and temporary fixing means. The outer steel pipe is made of a steel pipe and has a simple shape. Therefore, the outer steel pipes can be prepared in advance and can be robot-welded, which enables automation in factories, and is expected to reduce manufacturing costs and achieve uniform quality.

[0034] The column base that can be provided by the column base structure according to this embodiment has the effect of protecting columns in logistics facilities and the like, and the outer shell provides physical protection against contact with forklifts and the like. Furthermore, it is possible to provide a column base that is expected to have improved deformation performance due to improved column base rigidity, thereby achieving the effect of improving deformation performance against horizontal loads and improving earthquake resistance. In addition, it is possible to provide a column base that is expected to reduce the cross-section of the member by streamlining the cross-section calculation, thereby shortening the compression buckling length and lateral buckling length, and by setting the calculation position of the upper floor column to the top of the outer shell, it is possible to optimize the cross-section of the member. Furthermore, it is possible to connect K-type or X-type braces to the outer steel pipe, which allows for development into a brace structure, ensuring flexibility in structural design.

[0035] In the column base structure according to this embodiment, when the temporary fixing means is a means using the second gusset plate, the third gusset plate, and the second gusset joining means by bolt joining, the following effects are achieved. By making the bolt holes in the bolt joints elongated, it is possible to adjust the angle of the column in the direction of gravity, which has the effect of making it easier to adjust the accuracy of the erection.

[0036] In the column base structure according to this embodiment, when the temporary fixing means is a means using a guide plate, the following effects are achieved. The steel column of the upper floor is temporarily fixed by simply inserting the outer steel pipe into the temporary fixing space formed by a plurality of guide plates attached to the inside of the outer steel pipe and fitting the lowest part of the steel column of the upper floor into the lower guide part. This has the effect of reducing the amount of work required for construction on site.

[0037] Furthermore, in the temporary fixing step, if the upper floor steel column is temporarily fixed with a gap of approximately 5 mm in the vertical direction between the upper floor steel column and the upper diaphragm, this gap has the effect of making it possible to position the upper floor steel column vertically even if there is a foreign object on the upper diaphragm. As mentioned above, when the temporary fixing means is a means using a first gusset plate, angle iron, and first gusset joining means, or a means using a second gusset plate, a third gusset plate, and a second gusset joining means using bolt joining, adjustments such as providing a gap can be easily made. [Explanation of symbols]

[0038] 1 Pillar base structure 11 Upper diaphragm 12 Shell steel pipe 13 Temporary fixing means 131 First gusset plate 132 Angle iron 133 First gusset joining means 134 Second gusset plate 135 Third gusset plate 136 Second gusset joining means 137 Guide Plate 138 Lower guide part 139 Cover Plate 14 Cast concrete space 15 Temporary Fixed Space Pu Upper floor steel column Pl Lower floor steel column Jo joint Be Liang Dl Lower diaphragm

Claims

1. A column base structure for an upper floor steel column when installing an upper floor steel column that is thinner than a lower floor steel column on an upper floor, The column base is located at the top of a joint portion where a column and a beam are joined using a through diaphragm, The column base structure is An upper diaphragm which is a through diaphragm above the connection portion; An outer shell steel pipe located above the upper diaphragm and installed so as to form a poured concrete space therein with the upper diaphragm and the upper floor steel column; Temporary fixing means for temporarily fixing the upper floor steel column to the outer shell steel pipe; A column base structure comprising:

2. The column base structure according to claim 1, The temporary fixing means comprises one or more pairs of a first gusset plate set on the upper floor steel column and an angle iron set on the inner periphery of the outer shell steel pipe, and has a first gusset joining means for joining the first gusset plate and the angle iron. A column base structure characterized by:

3. The column base structure according to claim 1, The temporary fixing means comprises one or more sets of a second gusset plate set on the upper floor steel column and a third gusset plate set on the inner periphery of the outer shell steel pipe, and has a second gusset joining means for joining the second gusset plate and the third gusset plate. A column base structure characterized by:

4. The column base structure according to claim 1, The temporary fixing means is a means comprising a plurality of guide plates set on the inner periphery of the outer shell steel pipe to form a temporary fixing space into which the upper floor steel column is inserted to temporarily fix the upper floor steel column at the upper position of the outer shell steel pipe, and a lower guide part set on the upper diaphragm to temporarily fix the lowest part of the upper floor steel column. A column base structure characterized by:

5. A method for constructing a column base using the column base structure according to any one of claims 1 to 4, The column base construction method includes: a temporary fixing means setting step of setting the temporary fixing means to the outer shell steel pipe and the upper floor steel column or the upper diaphragm; a diaphragm welding step of welding the upper diaphragm and the lower diaphragm to the joint portion to fabricate a column-beam joint; an outer shell steel pipe welding step of welding the lower floor steel column and the outer shell steel pipe to the column-beam joint; a temporary fixing step of inserting the upper floor steel column into the outer shell steel pipe and temporarily fixing the upper floor steel column vertically by the temporary fixing means; A concrete pouring step of pouring concrete into the pouring concrete space; A method comprising:

6. The column base construction method according to claim 5, further comprising: In the temporary fixing step, the upper floor steel column is temporarily fixed with a gap of about 5 mm in the vertical direction between the upper floor steel column and the upper diaphragm. A method characterized by:

Images