Evaluation method for erection pieces

Abstract

This invention provides an evaluation method for erection pieces that allows for the assessment of whether or not an erection piece is suitable. [Solution] When a column to be added to a previously erected column is temporarily fixed with a fixing jig, the axial force applied to the column joint where the previously erected column and the added column are joined, and the tensile and compressive forces acting on the temporary fixing part where the erection pieces are temporarily fixed with a fixing jig due to the bending moment generated at the column joint by the horizontal force, are used to calculate the tensile displacement of the temporary fixing part where the tensile force acts and the compressive displacement of the temporary fixing part where the compressive force acts, using the elastic stiffness of the erection piece and the fixing jig. The displacement obtained by subtracting the compressive displacement from the tensile displacement is divided by the distance between the temporary fixing part where the tensile force acts and the temporary fixing part where the compressive force acts to calculate the rotation angle of the added column, and the strength of the erection piece is evaluated as acceptable when the calculated rotation angle is less than or equal to the elastic limit rotation angle.

Description

Technical Field

[0001] The present invention relates to a method for evaluating an erection piece in a wireless construction method of a steel structure using an erection piece and a fixing jig.

Background Art

[0002] Conventionally, in a steel structure, a so-called wireless construction method is known in which a steel column is built into a floor slab and then a new steel column is added thereon. In the wireless construction method, an erection piece made of a steel plate piece that enables the suspension of these steel columns is attached between the upper end portion of the previously built-in steel column and the lower end portion of the added steel column. Then, by attaching and operating a fixing jig to the erection pieces of both steel columns, the position of the steel column to be added is adjusted and temporarily fixed with respect to the previously built-in steel column. Then, a beam is joined to the column using a temporary bolt between the temporarily fixed steel columns, and after adjustments such as repositioning (making the members at the correct angle in the plane and making the columns vertical), the temporary bolt at the joint of the column and the beam is replaced with a main bolt and tightened, and then the columns are welded together to be integrated. By repeating this process, a steel structure is constructed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a wireless construction method that repeats such a process, since the structure during construction is unstable, safety considerations have been made so that accidents do not occur. However, in these considerations, it was unclear whether the performance actually required for the column joint was obtained. Therefore, in view of the above-mentioned problems, the present invention aims to provide an evaluation method for erection pieces that enables the evaluation of the suitability of erection pieces for use in wireless construction methods for steel frame structures using erection pieces and fixing jigs. [Means for solving the problem]

[0005] As an embodiment of the method for evaluating erection pieces to solve the above problem, the method for evaluating the strength of erection pieces used in a wireless construction method in which erection pieces, which are welded to a column that has been erected in advance and a column that is to be added to that column, are temporarily fixed together with a fixing jig, and the method evaluates the strength of erection pieces, and when the column to be added to the column that has been erected in advance is temporarily fixed together with a fixing jig, the axial force applied to the column joint where the column that has been erected in advance and the column that is to be added to join are compared with the bending moment generated at the column joint due to the horizontal force. Based on the tensile and compressive forces acting on the temporary fixing points where the erection pieces are temporarily fixed together with a fixing jig, the tensile displacement of the temporary fixing point under tensile force and the compressive displacement of the temporary fixing point under compressive force are calculated using the elastic stiffness of the erection piece and the fixing jig. The rotation angle of the extended column is calculated by subtracting the compressive displacement from the tensile displacement and dividing the resulting displacement by the distance between the temporary fixing point under tensile force and the temporary fixing point under compressive force. The strength of the erection piece is evaluated as acceptable if the calculated rotation angle is less than or equal to the elastic limit rotation angle. According to this embodiment, by calculating the rotation angle of the column, it is possible to evaluate whether or not an erection piece can be used in a wireless construction method for steel frame structures that utilizes an erection piece and a fixing jig. As an embodiment of the method for evaluating erection pieces, the method for evaluating the strength of erection pieces used in a wireless construction method in which erection pieces, which are welded to columns that are to be added to the columns that have been erected in advance, are temporarily fixed together with fixing jigs, is to be used to evaluate the strength of erection pieces. The method involves calculating the load acting on each erection piece based on the axial force acting on the column joint where the column that has been erected in advance and the column that is to be added are joined, and the tensile and compressive forces acting on the temporarily fixed part where the erection pieces are temporarily fixed together with fixing jigs due to the bending moment generated at the column joint by the horizontal force. The stress at the welded part between the erection piece and the column is calculated assuming that the load acts on each erection piece, and the strength of the erection piece is evaluated by comparing the calculated stress with the elastic limit load of the erection piece. Furthermore, as another aspect of the evaluation method for the erection piece, the rotation angle may be calculated separately for the following cases: when the axial force is greater than the tensile force acting on the erection piece due to the bending moment; when the axial force is equal to the tensile force acting on the erection piece due to the bending moment; and when the axial force is less than the tensile force acting on the erection piece due to the bending moment, and the elastic limit load of the erection piece is greater than or equal to the compressive force acting on the erection piece. [Brief explanation of the drawing]

[0006] [Figure 1] This diagram shows a column joint constructed using a wireless method. [Figure 2] This is a plan view of an erection piece attached to a column. [Figure 3] This diagram shows an example of the arrangement of erecting pieces. [Figure 4] This is a plan view of the fixing jig. [Figure 5] This is a cross-sectional view of the main part when the fixing jig is applied to the erection piece. [Figure 6]This is a diagram modeling a column joint. [Figure 7] This diagram shows the dominant range of the column-beam axial force N acting on the column joint being evaluated. [Figure 8] This diagram shows the relationship between the axis of rotation of the bending moment and the fixing jig when a horizontal force is applied to a column. [Figure 9] This graph shows the relationship between the load and deformation of the ring. [Figure 10] This graph shows the load-deformation relationship of a load-supporting mechanism. [Figure 11] This graph shows the load-displacement relationship of an erecting piece. [Figure 12] This diagram shows the relationship between the weight of the column and beam and the tensile force generated by the bending moment. [Figure 13] This figure shows the relationship between the calculated rotation angle and the bending moment. [Figure 14] This is a block diagram showing the hardware configuration of the evaluation device. [Modes for carrying out the invention]

[0007] The present invention will be described in detail below through embodiments of the invention. However, the following embodiments are not intended to limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the solution of the invention; rather, they include configurations that can be selectively adopted.

[0008] Figure 1 shows a column joint using the wireless construction method. As shown in the figure, the wireless construction method according to this embodiment includes a step of temporarily fixing the new column 10 on top of the previously erected column 10 by fixing the erection pieces 20,20 attached to the previously erected column 10 and the column 10 to be added to it using a fixing jig 30. Details of the erection pieces 20 and the fixing jig 30 will be described later.

[0009] In the following description, the part where the erection pieces 20 attached to the previously erected column 10 and the column 10 added thereto are fixed to each other by the fixing jig 30 is referred to as a temporary fixing part. Also, in the following description, although the shape of the column 10 is described as a square steel pipe, the shape of the column is not particularly limited.

[0010] [Regarding the erection piece] FIG. 2 is a plan view of the erection piece attached to the column. FIG. 3 is a view showing one form of the arrangement of the erection pieces. The erection piece 20 is a steel plate used when lifting the column 10 or temporarily fixing the column 10 to be added on top of the previously erected column 10 using the fixing jig 30. In the present embodiment, the erection piece 20 is formed as a rectangular flat plate member, and the end face on the long side is brought into contact with the column surface 10a so that the long side is parallel to the axis of the columns 10; 10 and the plate surface is perpendicular to the column surface 10a, and they are integrated by welding at the stage of manufacturing the column 10 in the factory. The welding of the erection piece 20 to the column 10 is, for example, made equivalent to full penetration, and the welding strength is made the same as the strength of the material used for the erection piece. Full penetration welding refers to welding that obtains the same strength as the base material. The fixing jig 30 is configured to include, for example, a hanging hole 22 used when lifting the column 10.

[0011] As shown in FIGS. 2(a) and (b), the position where the erection piece 20 is attached is set at a position axially separated by a predetermined distance from each end where the previously erected column 10 and the column 10 to be added thereto face each other, based on the dimensions of the fixing jig 30.

[0012] The material, shape of the erection piece 20, and the number of erection pieces 20 attached to each column 10 can be set based on the stress required when temporarily fixing the upper and lower columns 10; 10 with the fixing jig 30.

[0013] For example, if the stress is insufficient with the initially set erection piece 20, the erection piece 20 can be formed in the same shape but using a material with higher strength. Conversely, if the stress is excessive with the initially set erection piece 20, costs can be reduced by forming the erection piece 20 in the same shape but using a material with lower strength. For example, the erection piece 20 can be made of materials with different strengths, such as SS material (e.g., equivalent to SS400) or SM material (equivalent to SM490).

[0014] Furthermore, if the stress is insufficient with the initially set erection piece 20, another solution is to increase the stress by lengthening the welded portion of the erection piece 20 to the column 10. In this case, the shape may be modified to lengthen the welded portion to the column 10, taking into consideration the attachment of the fixing jig 30. For example, the shape of the erection piece 20 may be modified to include the aforementioned rectangular shape in part.

[0015] As mentioned above, the erection piece 20 can be made to accommodate the stress required when the upper and lower columns 10;10 are temporarily fixed with the fixing jig 30 by changing the material or shape. For example, an erection piece 20 with a standard strength can be standardized and prepared as a standard piece, and one that can withstand greater stress than the standard piece can be standardized and prepared as a heavy-duty piece, etc.

[0016] The number of erection pieces 20 provided depends on the stress required when temporarily fixing the upper and lower columns 10;10. For example, one can be placed in the center of each column face 10a of the column 10, as shown in Figure 2(a), or two can be placed at the same distance from the corners of each column face 10a, as shown in Figure 2(b). In this embodiment, the case in which one erection piece 20 is placed in the center of each column face 10a of the column 10, as shown in Figure 3, will be used for explanation.

[0017] The dimensions, shape, and weld length of the erection piece 20 described above are examples only and can be appropriately modified based on the strength that the fixing jig 30 can withstand and the strength required for the temporary fixing of the columns 10;10.

[0018] [Regarding fixing fixtures] Figure 4 is a plan view of the fixing jig. Figure 5 is a cross-sectional view of the main part when the fixing jig is applied to the erection piece. As shown in each figure, the fixing jig 30 is formed in a one-sided, annular shape, having a first slit 32 into which the erection piece 20 of the existing column 10 can be inserted, and a second slit 34 into which the erection piece 20 of the column 10 to be extended can be inserted.

[0019] At least one bolt is attached to the fixing jig 30 so as to be movable back and forth in relation to each slit 32, 34. In the illustrated embodiment, two bolt holes 35 are provided on both sides of slit 32, and one bolt hole 38 is provided on the underside of slit 32, so a total of three bolts are attached to slit 32 so as to be movable back and forth. In addition, two bolt holes 40 are provided on one side of slit 34, and two bolts are attached to slit 34 so as to be movable back and forth.

[0020] The fixing jig 30 can be formed, for example, by making slits in a steel plate with a thickness of 50 mm to 80 mm. The first slit 32 and the second slit 34 may be made separately, but it is preferable to have one slit that serves both purposes, as shown in the figure. In addition, to compensate for the reduction in strength due to the slits 32 and 34, two reinforcing plates 42 are welded so as to cover a portion of each slit 32 and 34.

[0021] With the fixing jig 30 configured in this way, for example, a stopper 24 is attached upward to the erection piece 20 of the column 10 to be extended, the erection piece 20 is inserted into the slit 34 of the fixing jig 30 and the fixing jig 30 is suspended, the column 10 to be extended is lowered above the existing column 10 with the stopper 24 preventing it from falling, the fixing jig 30 is moved in a pendulum-like motion and the erection piece 20 of the existing column 10 is inserted into the slit 32, thereby positioning the fixing jig 30 in the predetermined position.

[0022] After positioning the fixing jig 30 in the predetermined location, a bolt 33 is screwed into the bolt hole 35 related to the first slit 32, and then a bolt 36 is screwed into the bolt hole 38 to connect the fixing jig 30 to the erection piece 20 of the existing column 10. Furthermore, a bolt 39 is screwed into the bolt hole 40 related to the second slit 34 to connect the fixing jig 30 to the erection piece 20 of the newly installed column 10.

[0023] Furthermore, as shown in Figures 4 and 5, the fixing jig 30 includes a load support mechanism 50 that is positioned in the gap 52 formed between the erection piece 20 of the existing column 10 and the erection piece 20 of the new column 10 within the slit 34 of the fixing jig 30.

[0024] The load support mechanism 50 supports the load applied from the newly installed column 10 together with the existing column 10, and is configured to include a cam arm 54, a seat plate 56, a shim plate 58, and a screw member 60.

[0025] The cam arm 54 has an action portion 62, an input portion 63 spaced laterally from the action portion 62, and a pivot portion 64 spaced laterally and downward from the action portion 62 and the input portion 63, which contacts the erection piece 20. The input portion 63 is located laterally from the action portion 62, but it can be directly to the side, or it can be above or below the action portion 62. In contrast, the pivot portion 64 is positioned laterally and downward from the action portion 62 and the input portion 63, so that the action portion 62, the input portion 63, and the pivot portion 64 form a lever.

[0026] In the illustrated embodiment, the cam arm 54 is formed by grinding and normalizing structural carbon steel to the following shape. As shown in Figure 5(a), the working portion 62 of the cam arm 54 has an upwardly convex cylindrical surface 65, and the pivot portion 64 of the cam arm 54 has a downwardly convex cylindrical surface 66.

[0027] The cylindrical surfaces 65 and 66 are formed by connecting circular arcs with radii R1 and R2, respectively, over a constant width perpendicular to the plane of the paper. Radii R1 and R2 may be the same size or may be different sizes. Furthermore, the width of the cam arm 54 perpendicular to the plane of the paper should be wider than the thickness of the erection piece 20.

[0028] The cylindrical surface 66 of the fulcrum 64 only needs to make line contact with the shim plate 58 and function as the fulcrum of the lever, and the central angle should be around a few degrees. On the upper side of the cam arm 54, an inclined surface 67 is connected to the cylindrical surface 65, and a horizontal surface 68 is further connected to the inclined surface 67. On the other hand, on the lower side of the cam arm 54, two inclined surfaces 69 and 70 are connected to the cylindrical surface 66, with inclined surface 69 connected to an extension of the cylindrical surface 65 and inclined surface 70 connected to a vertical surface 71.

[0029] The seat plate 56 is positioned between the cam arm 54 and the erection piece 20 of the newly installed column 10, and is in partial contact with the erection piece 20. It is formed to have an engaging portion 74 that contacts the working portion 62 of the cam arm 54, and a screw hole 75 that penetrates vertically and is provided at a laterally spaced distance from the engaging portion 74, in a portion corresponding to the input portion 63 of the cam arm 54. In the illustrated embodiment, the seat plate 56 is made by grinding structural carbon steel, and the engaging portion 74 of the seat plate 56 has a cylindrical surface that is concave upwards. This cylindrical surface is formed to fit into the cylindrical surface of the working portion 62 of the cam arm 54.

[0030] The shim plate 58 is positioned between the cam arm 54 and the existing erection piece 20, and is in contact with the pivot point 64 of the cam arm 54 and the erection piece 20. The shim plate 58 is formed such that the surface 59 that contacts the pivot point 64 of the cam arm 54 is an inclined surface. This allows the shim plate 58 to be inserted and brought into contact with the pivot point 64 and the erection piece 20 even if the size of the gap between the cam arm 54 and the erection piece 20 changes. Alternatively, the cam arm 54 can be mounted directly on the erection piece 20. In this case, the shim plate 58 can be omitted.

[0031] The threaded member 60 is screwed into the threaded hole 75 of the seat plate 56 and contacts the input portion 63 of the cam arm 54 to input a support load to the cam arm 54. In the illustrated embodiment, it is a hexagon socket head bolt. It is preferable that the tip of the threaded member 60 or the surface of the input portion 63 of the cam arm 54 have a low coefficient of friction. For example, the tip of the threaded member 60 can be made spherical, or a resin plate such as nylon can be attached to the input portion 63 to achieve a low coefficient of friction.

[0032] The load support mechanism 50 can be configured by inserting the cam arm 54 and the seat plate 56 into the gap between the erection pieces 20, 20 within the slit 34 of the fixing jig 30, and then inserting the shim plate 58, thus avoiding the need for adjustment with the shim plate 58. When a tool is inserted into the hexagonal hole of the screw member 60 and the screw member 60 is screwed in, the input part 63 of the cam arm 54 is pushed downward, and the working part 62 of the cam arm 54 rotates around the pivot point 64 and moves upward. This applies a support load to the erection piece 20 of the newly installed column 10, so that, for example, a tilted newly installed column 10 can be made closer to vertical. By performing such adjustments for all load support mechanisms 50, the newly installed column 10 can be made vertical. As the working part 62 of the cam arm 54 moves, the cylindrical surface of the working part 62 and the cylindrical surface of the engaging part 74 of the seat plate 56 engage, causing the seat plate 56 to move horizontally. The load on the column 10 is supported by friction between the threaded member 60 and the threaded hole 75 of the base plate 56.

[0033] In this way, by using the erection pieces 20 installed on the existing column 10 and the new column 10, the fixing jig 30, and the load support mechanism 50, the new column 10 can be temporarily fixed to the existing column 10. In other words, the newly installed column 10 will be supported by the strength of the erection piece 20 of the column 10, the erection piece 20 of the previously erected column 10, the fixing jig 30 connecting them, and the load support mechanism 50.

[0034] In the erection evaluation method according to this embodiment, the rotation angle at the column joint is used as an evaluation index to determine whether the erection piece 20 in a wireless construction method using the erection piece 20 and fixing jig 30 can withstand a load (such as horizontal (external) force Q or column beam weight N).

[0035] [Method for calculating the rotational stiffness of column joints using a fixing jig] [Modeling of column joints] Figure 6 is a model of a column joint. In this embodiment, the column joint shown in Figure 6(a) is modeled as shown in Figure 6(b), and the rotation angle θ of the extended column 10 is calculated based on the forces acting on the erection piece 20 and the fixing jig 30 due to the horizontal force Q and the column-beam weight (axial force due to the column-beam weight) N. In the following description, the column-beam weight N may be referred to as the column-beam axial force N, or simply as the axial force N.

[0036] For example, as shown in Figure 6(b), when a horizontal force Q acts from left to right on the plane of the paper, a tensile force acts on the column fixing point (tentative name) upstream of the horizontal force Q, and a compressive force acts on the column fixing point downstream of the horizontal force Q. The tensile force generated at the upstream column fixing point is supported by the erection pieces 20 attached to the upper and lower columns 10 and the ring 31 of the fixing jig 30 provided to surround the upper and lower erection pieces 20, while the tensile force generated at the downstream column fixing point is supported by the erection pieces 20 attached to the upper and lower columns 10 and the load support mechanism 50 provided between the upper and lower erection pieces 20.

[0037] Figure 7 shows the dominant range of the column-beam axial force N acting on the column joint to be evaluated. In this embodiment, the column-beam axial force N is calculated as a range as shown in the figure. The planar (XY) range of the column joint to be calculated is the range enclosed by half the distance between adjacent columns 10, as shown in Figure 7(a). In the vertical (Z) direction, as shown in Figure 7(b), in the case of 3 stories (floors) per section, it is the weight of all the main beams 14 and secondary beams 16 included in the aforementioned planar range of each story. The length of the main beams 14 and secondary beams 16 is the distance between the centers.

[0038] Furthermore, the main beam connected to the column 10 is attached with temporary bolts, and is assumed to be in a pin-connected state to the column 10. For example, as shown in Figures 1 and 6(b), when supported by four fixing jigs 30, the load (weight) W received by one fixing jig 30 can be considered to be 1 / 4 of the column-beam axial force N (W = N / 4).

[0039] Figure 8 shows the relationship between the axis of rotation of the bending moment M when a horizontal force acts on the column and the fixing jig 30. The vertical force PM applied to the fixing jig 30 is obtained by dividing the bending moment M at the column joint position by the distance a between the jigs.

[0040] For example, if the column 10 is rectangular in shape, the fixing jig 30 is installed in the center of each face 10a of the column 10 as described above. As shown in Figures 8(a) and (b), the vertical force PM generated in the fixing jig 30 will be different when a horizontal force Q is received from the X or Y direction compared to when a horizontal force Q is received from a direction at a 45° angle to the X or Y direction.

[0041] Specifically, as shown in Figure 8(a), if we represent the vertical force generated in the fixing jig 30 when a horizontal force Q is received from the X or Y direction as PM1, the vertical force PM1 is obtained as PM1 = M / (1·a) = M / a. Also, as shown in Figure 8(b), if we represent the vertical force generated in the erection jig when a horizontal force Q is received from a direction at a 45° angle to the X or Y direction as PM2, the vertical force PM2 is obtained as PM2 = M / (0.707a × 2) = 0.707 × M / a.

[0042] Therefore, when the column 10 is rectangular in shape, the vertical force PM1 generated in the fixing jig 30 due to the bending moment M is greater than the vertical force PM2 (PM1 > PM2). Thus, the direction (X direction, Y direction) when the vertical force PM1 is present, which is unfavorable for the fixing jig 30, is adopted as the direction in which the horizontal force is applied.

[0043] In the evaluation method according to this embodiment, each component of the fixing jig 30 that supports tensile and compressive forces, such as the ring 31, load support mechanism 50, and erection piece 20, is considered as a spring, and the rotation angle θ is determined by calculating the compressive stiffness and tensile stiffness from the vertical stiffness of the ring 31, load support mechanism 50, and erection piece 20. In the following explanation, the vertical stiffness of the ring 31 constituting the fixing jig 30 is referred to as the tensile elastic stiffness Rk, the vertical stiffness of the load support mechanism 50 is referred to as the compressive elastic stiffness Ck, and the vertical stiffness of the erection piece 20 is referred to as the in-plane elastic stiffness Ek. The in-plane direction refers to the direction in which the erection piece 20 deforms parallel to the column surface without deforming in the thickness direction of the plate.

[0044] [Vertical rigidity of each component in the column joint] The tensile elastic stiffness Rk, compressive elastic stiffness Ck, and in-plane elastic stiffness Ek of each component can be obtained beforehand, for example, through experiments.

[0045] Figure 9 is a graph showing the load-deformation relationship of ring 31. The tensile elastic stiffness Rk of ring 31 can be obtained, for example, by performing a tensile test to measure the tensile load and tensile displacement, and based on the load-deformation relationship shown in Figure 9.

[0046] Figure 10 is a graph showing the load-deformation relationship of the load support mechanism 50. The compressive elastic stiffness Ck of the load support mechanism 50 can be obtained, for example, by performing a compression test, measuring the compressive load and compressive displacement, and based on the load-deformation relationship shown in Figure 10.

[0047] Figure 11 is a graph showing the load-displacement relationship of the erection piece 20. The in-plane elastic stiffness (referred to as in-plane stiffness) Ek of the erection piece 20 can be obtained, for example, by performing a bending shear test, measuring the load-displacement, and based on the load-deformation relationship shown in Figure 11. For example, the in-plane stiffness Ek of the erection piece 20 can be determined according to the weld length and material.

[0048] [Calculation of rotation angle considering vertical stiffness on the tension and compression sides and column / beam weight] Figure 12 shows the relationship between the weight of the column and beam and the tensile force generated by the bending moment M. The symbols shown in Figure 12 are as follows: P: Tensile force acting on each erection piece on the tension side due to the bending moment M. W: Weight acting on each erection piece of the column / beam weight N Pt: Tensile force acting on each erection piece Pc: Compression force acting on each erection piece Py: Elastic limit load a: Distance between jigs δTt: Tensional displacement on the tension side (amount of tension displacement) δCc: Compression displacement on the compression side (amount of displacement on the compression side) The tensile force (compressive force) P is calculated using the formula P = (M / a) / n, where M is the bending moment and n is the number of fixing fixtures attached to one side of the column 10.

[0049] The rotation angle θ is calculated by considering different cases based on the relationship between the weight W acting on each erection piece and the tensile force P acting on each erection piece due to the bending moment M generated at the column joint. For details, Condition (1): When the weight W acting on each erection piece on the tension side is greater than the tensile force P acting on each erection piece due to the bending moment M generated at the column joint (weight W > tensile force P) (see Figure 12(a)), Condition (2): When the weight W per erection piece on the tension side is equal to the tensile force P acting on each erection piece due to the bending moment M generated at the column joint (column-beam weight W = tensile force P) (see Figure 12(b)), Condition (3): When the weight W per erection piece on the tension side is less than the tensile force P acting on each erection piece due to the bending moment M generated at the column joint, and the compressive force (compressive load) Pc on the compression side is less than or equal to the critical elastic load Py (weight W < tensile force P, and critical elastic load Py ≥ compressive force Pc) (see Figure 12(c)), The rotation angle θ is calculated in such a way.

[0050] [Condition (1) When weight W > tensile force P] In the case of condition (1), as shown in Figure 12(a), the tension-side erection piece 20 receives a compressive force Pc from the ring 31. Therefore, in the case of condition (1), we first determine the vertical stiffness on the tensile side (hereinafter referred to as the tensile vertical stiffness Kt). The tensile vertical stiffness Kt is obtained by the following equation 1. Tension-side vertical stiffness Kt = 1 / (1 / Ck + 1 / Ek) --- Equation 1 Furthermore, the vertical stiffness on the compression side (hereinafter referred to as the vertical stiffness on the compression side Kc) is determined. The compression-side vertical stiffness Kc is obtained by the following equation 2. Compressive vertical stiffness Kc = 1 / (1 / Rk + 1 / Ek) --- Equation 2 Next, we find the rotation angle θ at this time. The rotation angle θ is calculated from the relationship between the compressive displacement on the tension side and the compressive displacement on the compression side. If the compressive displacement on the tensile side is denoted as δTc, the compressive displacement on the tensile side δTc can be obtained by the following equation 3. δTc=Pt / Kc=(PW) / Kc ――――――Equation 3 Furthermore, if we denote the compression displacement on the compression side as δCc, the compression displacement δCc on the compression side can be obtained by the following equation 4. δCc=Pc / Kc=(-PW) / Kc ――――――Formula 4 The rotation angle θ can be calculated by subtracting the compression displacement δCc on the compression side from the compression displacement δTc on the tension side, and dividing by the distance a between the fixtures. The rotation angle θ is obtained by the following equation 5. θ = (δTc - δCc) / a ={(PW) / Kc-(-PW) / Kc} / a =2·P / (Kc·a) ------Equation 5 If we express the tensile force (or compressive force) P acting on each erection piece on the tension side using the bending moment M, then the relationship M = P·a holds, so equation 5 can be transformed into equation 5'. θ = 2·M / (Kc·a 2 ) ――――――Formula 5′ Therefore, the rotation angle θ in the case of condition (1) can be calculated using equation 5 or equation 5'.

[0051] [Condition (2) When weight W = tensile force P] In the case of condition (2), as shown in Figure 12(b), the vertical displacement on the tensile side is 0, and only the vertical displacement due to the vertical stiffness on the compression side (hereinafter referred to as the compression side vertical stiffness Kc) occurs. Therefore, in the case of condition (2), we first determine the vertical stiffness Kc on the compression side. The compression-side vertical stiffness Kc is obtained by the following equation 6. Compressive vertical stiffness Kc = 1 / (1 / Ck + 1 / Ek) --- Equation 6 The tensile vertical stiffness Kt can be obtained in the same way as condition (1) by the following equation 7. Tension-side vertical stiffness Kt = 1 / (1 / Rk + 1 / Ek) --- Equation 7 Next, we find the rotation angle θ at this time. The rotation angle θ is calculated from the relationship between the compressive displacement on the tension side and the compressive displacement on the compression side. If the compressive displacement on the tensile side is denoted as δTc, then the compressive displacement on the tensile side δTc can be expressed as shown in Equation 8 below. δTc=0 --------Equation 8 Furthermore, if we denote the compression displacement on the compression side as δCc, the compression displacement δCc on the compression side can be obtained by the following equation 9. δCc=(-PW) / Kc=-2P / Kc ――――――Equation 9 The rotation angle θ can be calculated by subtracting the compression displacement δCc on the compression side from the compression displacement δTc on the tension side, and dividing by the distance a between the fixtures. The rotation angle θ is obtained by the following equation 8. θ = (-δCc) / a =2P / Kc / a ――――――Equation 9 If we express the tensile force (or compressive force) P acting on each erection piece on the tension side using the bending moment M, then the relationship M = P·a holds, so equation 8 can be transformed into equation 10'. θ = 2·M / (Kc·a 2 ) ――――――Formula 10′ Therefore, the rotation angle θ in the case of condition (2) can be calculated using equation 10 or equation 10'.

[0052] [Condition (3) Weight W < Tensile force P, and critical elastic load Py ≥ compressive force Pc] In the case of condition (3), as shown in Figure 12(c), vertical displacement occurs due to the vertical stiffness on the tensile side (tensile vertical stiffness Kt) and vertical displacement occurs due to the vertical stiffness on the compressive side (compressive vertical stiffness Kc). Therefore, in the case of condition (3), we first determine the tensile vertical stiffness Kt and the compressive vertical stiffness Kc. The tensile vertical stiffness Kt is obtained by the following equation 11. Tension-side vertical stiffness Kt = 1 / (1 / Ck + 1 / Ek) --- Equation 11 The compression-side vertical stiffness Kc is obtained by the following equation 12. Compressive vertical stiffness Kc = 1 / (1 / Ck + 1 / Ek) --- Equation 12 Next, we find the rotation angle θ at this time. The rotation angle θ is calculated from the relationship between the compressive displacement on the tension side and the compressive displacement on the compression side. If the compressive displacement on the tensile side is denoted as δTc, then the compressive displacement on the tensile side δTc can be expressed as shown in Equation 13 below. δTt=Pt / Kt=(PW) / Kt ――――――Equation 13 Furthermore, if we denote the compression displacement on the compression side as δCc, the compression displacement δCc on the compression side can be obtained by the following equation 14. δCc=Pc / Kc=(-PW) / Kc ――――――Equation 14 However, Py≧Pc The rotation angle θ can be calculated by subtracting the compression displacement δCc on the compression side from the compression displacement δTc on the tension side, and dividing by the distance a between the fixtures. The rotation angle θ is obtained by the following equation 15. θ = (δTt - δCc) / a ={(PW) / Kt-(-PW) / Kc} / a =Kt·Kc{P·(Kc+Kt)-W·a(Kc-Kt)} / a ------Equation 15 If we express the tensile force (or compressive force) P acting on each erection piece on the tension side using the bending moment M, then the relationship M = P·a holds, so equation 15 can be transformed into equation 15'. θ={M·(Kc+Kt)-W·a·(Kc-Kt)} / (Kc·Kt·a 2 )――――Formula 15′ Therefore, the rotation angle θ in the case of condition (3) can be calculated using equation 15 or equation 15'. Here, the elastic limit rotation angle θe at the compression limit elastic load Py can be calculated by determining the rotation angle θ when the compressive force Pc acting on the compression-side erection piece 20 is equal to the elastic limit load Py. In other words, the rotation angle θ when the compressive force Pc and the elastic limit load Py are equal can be determined using equation 15 or equation 15'.

[0053] [Example of calculating the elastic limit rotation angle θe] The elastic limit rotation angle θe was calculated, for example, by setting the calculation conditions as follows and using conditions (1) to (3). Column size: 550mm (length of one side) x 550mm (length of one side) x 22mm (thickness) Erection piece: Welding length 200mm, plate thickness 22mm In-plane stiffness: 250 kN·cm (experimental value) Elastic limit load Py: 500kN (experimental value) Distance between jigs a = 750 mm Axial force N=100kN

[0054] Figure 13 shows the relationship between the calculated rotation angle θ obtained using conditions (1) to (3) and the bending moment M. In Figure 13, the slope of the line represents the rotational stiffness. The rotational stiffness changes at a rotation angle θ calculated in condition (2). Furthermore, at this time, when the compressive force (P+W) acting on the compression-side erection piece 20 reached the elastic limit load Py, the elastic limit rotation angle θe was 0.0147 rad and the bending moment was 302 kN·m.

[0055] Thus, by performing a static incremental analysis that considers the relationship between the rotation angle and bending moment of the column joint as shown in Figure 13, the rotation angle θ of the column joint can be determined. If the calculated rotation angle θ exceeds the elastic limit rotation angle θe, the erection piece 20 will exceed the elastic range and enter the plastic region, resulting in a "NG" (Not Good) judgment for the erection piece 20 with the weld length and plate thickness set in the calculation conditions.

[0056] The method for evaluating column joints in the wireless construction method described above can be used, for example, by utilizing a computer with a hardware configuration as shown in Figure 14, to determine the rotation angle θ of the column added at the joint. In other words, this computer can be configured as an evaluation device for column joints in the wireless construction method (hereinafter simply referred to as the evaluation device) 1. The evaluation device 1 can be a computer, for example, a mobile device such as a smartphone or tablet, or a notebook or desktop computer.

[0057] As shown in Figure 14, the evaluation device 1 is configured to include hardware resources such as a CPU (processor) or other arithmetic processing means 2, a storage means such as ROM or RAM 3, a communication means 4 that enables communication with other devices, a display means 5 such as a monitor, an external input / output interface for connecting magnetic or optical drives, and an input means 6 such as a keyboard or mouse.

[0058] The memory means 3 can store, for example, information about the fixing jig 30, such as the tensile elastic stiffness Rk of the ring 31 of the fixing jig 30 used to calculate the rotation angle θ; information about the load support mechanism 50, such as the compressive elastic stiffness Ck of the load support mechanism 50; information about the erection piece 20, such as the in-plane elastic stiffness Ek of the erection piece 20; information about the column to be evaluated; information about the position of the fixing jig 30, such as the distance a between jigs and the distance from each column face to the position where the fixing jig 30 is attached to the erection piece 20; information for determining whether the column joint is feasible, such as the elastic limit load Py; and an evaluation program for determining whether the column joint is feasible.

[0059] Furthermore, the information to be stored in the memory means 3 does not necessarily need to be stored in the memory means 3 in advance; it may be entered using the input means 6 as needed.

[0060] The evaluation program should ideally include, for example, formulas for calculating the rotation angle θ under each of the aforementioned conditions (1), (2), and (3), and a determination formula for determining whether or not a column joint is feasible based on the calculated rotation angle θ.

[0061] By having the calculation processing means 2 execute each process according to the evaluation program stored in the storage means 3, the evaluation device 1 can be made to function as a rotation angle calculation means for calculating the rotation angle θ of the extended column at the column joint, or as a determination means for determining whether or not the erection piece 20 at the column joint is acceptable.

[0062] As explained above, in the wireless construction method for assembling a steel frame building, the rigidity of the erection pieces 20 and the fixing jig 30 is obtained in advance. Based on the column-beam weight N and the bending moment M due to the horizontal force Q acting on the column joint between the previously erected column and the column to be added, the relationship between the magnitude of the forces W acting on each erection piece due to the column-beam weight N and the tensile force P acting on each erection piece due to the bending moment M is considered, and by statically analyzing the compressive force Pc and tensile force Pt acting on the erection piece 20, the relationship between the angle at which the column added to the previously erected column rotates (tilts) (rotation angle θ at the column joint) and the bending moment M is obtained. By comparing whether the rotation angle θ is within the range of the limit elastic stiffness of the erection piece 20, the feasibility of the erection piece 20 can be evaluated without complex calculations. In other words, when erection pieces 20;20 are temporarily fixed together with a fixing jig, the extended column is considered to be elastically supported by the erection piece 20 and the fixing jig 30. By performing a static incremental analysis that considers the relationship between the rotation angle and bending moment at the column joint due to the column-beam weight N and the horizontal force Q, the rotation angle of the column joint can be determined. By determining whether the rotation angle at that time is below the elastic limit rotation angle, the strength of the selected erection piece 20 can be evaluated.

[0063] In the evaluation method described in the above embodiment, when a new column is added to a previously erected column, the erection pieces 20;20 attached to the previously erected column and the added column by welding are temporarily fixed together with a fixing jig. At this point, the added column is considered to be elastically supported by the erection pieces 20 and the fixing jig 30. The angle at which the added column rotates (tilts) relative to the previously erected column due to the column-beam weight N and horizontal force Q acting on the column joint where the previously erected column and the added column are joined (rotation angle θ at the column joint) is used as a judgment index. Whether or not this angle is acceptable is evaluated based on the elastic stiffness of the erection piece and the fixing jig, thereby evaluating the suitability of the strength of the erection piece. However, the method is not limited to this.

[0064] As shown in equation 5' of condition (1), equation 10' of condition (2), equation 15' of condition (3) and Figure 13, there is a linear relationship between the rotation angle θ of the added column at the column joint and the bending moment M. By determining the rotation angle θ at the column joint, the bending moment M based on this rotation angle θ can be calculated. Therefore, instead of using the rotation angle θ of the column being extended at the column joint, the bending moment M may be used to evaluate the strength of the erection piece 20.

[0065] In this case, based on the column-beam weight N and the bending moment M due to the horizontal force Q acting on the column joint between the previously erected column and the column to be added, the relationship between the magnitude of the force W acting on each erection piece due to the column-beam weight N and the tensile force P acting on each erection piece due to the bending moment M is divided into cases, and the compressive force Pc and tensile force Pt acting on the erection piece 20 are statically analyzed. When the obtained compressive force Pc and tensile force Pt act on each erection piece 20, the stress at the weld between the column surface 10a and the erection piece 20 is compared with the short-term allowable stress of the erection piece 20 to evaluate (determine) whether the erection piece 20 is acceptable or not.

[0066] Here, the stress in the welded portion of the erection piece 20 refers to the combined stress when bending stress and shear stress act simultaneously on the welded portion. The bending stress σ generated in the weld can be calculated as σ = M / Z, and the shear stress τ generated in the weld can be calculated as τ = (P + W) / As, and the combined stress fb can be calculated as fb = (σ 2 +3τ 2 ) 0.5 This can be calculated by the following equation. Here, M is the bending moment obtained by the aforementioned analysis, P is the tensile force acting on each erection piece on the tension side due to the bending moment M, W is the weight of the column-beam weight N acting on each erection piece, Z is the section modulus of the erection piece 20, and As is the cross-sectional area of ​​the erection piece 20.

[0067] Furthermore, when calculating the bending stress σ and shear stress τ of the welded joint, the section modulus Z and cross-sectional area As used are those of the thinner column 10 plate if the column 10 plate thickness is thinner than the piece plate thickness. Also, if the thickness of the column 10 and the thickness of the erection piece 20 are the same, the bending stress and shear stress of the erection piece 20 may be used. [Explanation of Symbols]

[0068] 1 construction planning device, 10 columns, 20 erection pieces, 30 fixing jigs, 50 Load support mechanism.

Claims

1. A method for evaluating the strength of erection pieces used in a wireless construction method for assembling steel frame buildings, in which erection pieces attached by welding to pre-erected columns and columns to be added to those columns are temporarily fixed together with fixing jigs, wherein the strength of the erection pieces is evaluated. When a column to be added to a previously erected column is temporarily fixed with a fixing jig, the axial force acting on the column joint where the previously erected column and the added column are joined, and the tensile and compressive forces acting on the temporarily fixed part where the erection pieces are temporarily fixed with the fixing jig due to the bending moment generated at the column joint by the horizontal force, are used to calculate the tensile displacement of the temporarily fixed part under tensile force and the compressive displacement of the temporarily fixed part under compressive force, using the elastic stiffness of the erection piece and the fixing jig. The rotation angle of the extended column is calculated by subtracting the compressional displacement from the tensile displacement, and then dividing the resulting displacement by the distance between the temporary fixing point where tensile force acts and the temporary fixing point where compressive force acts. A method for evaluating an erection piece, characterized by evaluating the strength of the erection piece by determining that it is acceptable when the calculated rotation angle is less than or equal to the elastic limit rotation angle.

2. A method for evaluating the strength of erection pieces used in a wireless construction method for assembling steel frame buildings, in which erection pieces attached by welding to pre-erected columns and columns to be added to those columns are temporarily fixed together with fixing jigs, wherein the strength of the erection pieces is evaluated. When a column to be added to a previously erected column is temporarily fixed with a fixing jig, the load acting on each erection piece is calculated based on the axial force acting on the column joint where the previously erected column and the added column are joined, and the tensile and compressive forces acting on the temporarily fixed part where the erection pieces are temporarily fixed with a fixing jig due to the bending moment generated at the column joint by the horizontal force. Assuming that the calculated load acts on each erecting piece, the stress at the weld between the erecting piece and the column is calculated. A method for evaluating an erection piece, characterized by comparing the calculated stress with the elastic limit load of the erection piece to evaluate the strength of the erection piece.

3. The aforementioned rotation angle is, When the aforementioned axial force is greater than the tensile force acting on the erecting piece due to the bending moment, The case where the axial force is equal to the tensile force acting on the erecting piece due to the bending moment, The method for evaluating an erection piece according to claim 1, characterized in that the calculation is performed separately for the case where the axial force is greater than the tensile force acting on the erection piece due to the bending moment, and the case where the elastic limit load of the erection piece is greater than or equal to the compressive force acting on the erection piece.

Images