JP6911069B2 - Unit truss - Google Patents

Description

The present invention relates to a unit truss, in particular, upper chord member, lower chord member, the diagonal members, and a three-dimensional truss consists of horizontal braces and plants produced by dividing the three-dimensional truss unit, carried to the construction site and about the unit truss assemble.

A truss structure is a type of structural framework that is a straight member and is composed of triangles as a unit. The end nodes of each member are all pin-joined, and it is a structural form that supports a large frame. be. The truss structure includes a flat truss in which all members are present in one plane and a three-dimensional truss in which members are three-dimensionally gathered at one node. The unit truss is a truss structure in which a flat truss is connected by a stiffener or the like to form a three-dimensional truss, and the three-dimensional truss is divided into units, manufactured in a factory, and carried to a construction site for assembly.

The truss structure is designed to withstand fixed loads such as supporting roofing materials, loads by people and objects, wind loads due to wind pressure, and seismic loads due to earthquakes. The truss structure is designed to bear the bending moments generated by the upper and lower chords and the shear forces generated by the diagonals. Then, the bundle member is provided at a load point where the load is intensively applied.

This truss structure includes members constituting the truss structure and joints in which the members are concentrated. The weight of the members constituting the truss is generally overwhelmingly larger than the weight of the joint. On the other hand, the processing cost of the members constituting the truss is generally overwhelmingly smaller than the processing cost of the joint portion.

Generally, the price of a steel structure is calculated by multiplying the weight of the entire steel frame by the unit price. On the other hand, in the case of a truss structure, an area calculation method is adopted in which the area of the truss roof is calculated by multiplying the unit price. That is, in the case of the truss structure, as described above, the ratio of the processing cost of the joint portion is overwhelmingly larger than the processing cost of the entire truss, and the actual cost cannot be accurately reflected by the weight calculation method. On the other hand, regarding the material cost, the ratio of the weight of the joint is overwhelmingly smaller than the weight of the entire truss, and there is no problem in the area calculation method. The total cost of the truss structure mainly consists of material cost and processing cost. Therefore, when looking at the total cost of the truss structure, it is necessary to pay attention to the balance between the material cost and the processing cost.

(Conventional unit truss technology)
FIG. 10 shows the member configuration of the conventional truss and the details of the lower chord member joint in an explanatory view and a plan view. Further, in the present specification, the conventional truss structure is hereinafter referred to as "conventional truss 1'". FIG. 10A shows the member configuration of the conventional truss 1', and FIG. 10B shows the details of the joint portion of the lower chord node 3b'. As shown in FIG. 10A, the conventional truss 1'is provided with a bundle member 6'that connects the upper chord node 3a'and the lower chord node 3b'. Further, as shown in FIG. 10B, in the conventional truss 1', a horizontal brace 5'was provided on the upper chord surface. Therefore, in the detail of the joint portion of the first chord node 3a', there is a bundle material penetration portion 22'through which the bundle material 6'penetrates, and in order to form this through hole, a “notch 14'” is formed in the gusset plate 27'. It was provided. Further, the four horizontal brace intersections 19'are intersected by two to form a horizontal brace intersection 19a'and a horizontal brace intersection 19b', and the stiffener 10'is stiffened in the upper chord member 2a'and the lower chord member 2b'. The material intersection point 20'is formed. However, none of the horizontal brace intersections 19a'and 19b' and the stiffener intersection 20' intersects the structural core 21', and a local bending moment is generated. This is because a local bending moment is generated by the penetration of the bundle member 6'. Further, FIG. 11 shows a perspective view of the joining details of the lower chord member 2b'of the conventional truss 1'. Conventionally, at the lower chord node 3b'of the truss 1', a notch 14'is provided because the bundle member 6'forms the bundle member penetrating portion 22'. Further, adjacent units are connected to each other by the unit indirect alloy material 13'.

Patent Document 1 discloses a unit building and a method for constructing the unit building. Here, a reinforcing roof truss is installed above the box-shaped roof unit. Further, this reinforcing roof truss has a truss structure called "how truss", and the roof truss is formed without using a bundle member.

Further, Patent Document 2 discloses a roof truss unit capable of increasing the size of the roof unit and a roof truss structure. Here, a truss structure called "double how truss", which is a deformation using a bundle material, is disclosed. Further, FIG. 6 of Patent Document 2 describes various examples of member configurations of the chevron truss.

Further, Patent Document 3 discloses a roof structure of a building for reducing construction man-hours. A truss structure provided with a bundle member is described in FIGS. 2 and 7 of Patent Document 3.

Further, Patent Document 4 discloses a building structure, a building, and a building construction method. Here, a truss structure in which parallel chord trusses are combined in the orthogonal direction is disclosed. This three-dimensional truss has a truss structure called "finks type" without a bundle member, but a member corresponding to the bundle member is provided at a position where the column member is extended at the upper part of the lower column member.

Further, Patent Document 5 discloses a joint structure of a truss structure. Here, it is described that at least one of the gusset plates joined to the upper end and the lower end of the bundle material, which is less affected by the shearing force, is not welded to the bundle material, thereby omitting the welding work. ..

Further, Patent Document 6 discloses a roof structure. Here, it is described that a horizontal brace is provided on the outer peripheral portion of the roof frame to increase the horizontal rigidity.

Japanese Unexamined Patent Publication No. 2005-307642 JP-A-2015-172290 Japanese Unexamined Patent Publication No. 2013-221295 Japanese Patent No. 6433107 Japanese Unexamined Patent Publication No. 10-252141 Japanese Unexamined Patent Publication No. 11-256749

In order to reduce the manufacturing cost of the entire unit truss, it is effective to reduce the machining degree of the joint and reduce the machining cost. Then, in order to reduce the degree of processing of the joint portion, it is effective to reduce the number of members attached to the joint portion. However, if the number of members attached to the joint is reduced, the stress generated in the entire truss structure may be redistributed and the cross section of the member may become large. As a result, there is a problem that the weight of the truss member increases and the price of the entire unit truss rises.

On the other hand, if the members that make up the truss structure are rigorously designed and the weight is reduced to the utmost limit in order to reduce the manufacturing cost of the entire unit truss, the joints of the truss structure will be wrinkled and structural safety will be impaired. There is a risk. Further, since the rigidity of the truss structure is lowered, wrinkles may occur in the construction of the truss structure, which may impair the accuracy and safety of the construction of the truss.

The first object of the present application is to solve such a problem and to provide a unit truss in which the manufacturing cost of the entire truss structure is reduced by simplifying the detail of the joint portion which accounts for most of the manufacturing cost of the entire truss structure. ..

A second object of the present application is to solve such a problem and increase the weight of the truss structure by reducing the stress generated in the truss structure in contrast to the increase in the weight of the truss structure caused by the simplification of the details of the joint portion described above. To provide a unit truss with overall cost merit by offsetting the above.

To achieve the above object, unit truss according to the present invention, plane top chord member connecting the upper chord nodes together, the lower chord member connecting the lower chord node each other by a diagonal members for connecting the upper chord nodes and lower chord member A three-dimensional truss consists of a connecting material that connects the upper chord nodes of adjacent flat trusses, a stiffener that connects the lower chord nodes of adjacent flat trusses, and a horizontal brace provided only on the lower chord surface. a unit truss to form a, the upper chord node, an aggregation of the upper chord member and the joint skills material, the lower chord node, an aggregation of the the lower chord member complement Tsuyoshizai, connecting the upper chord nodes and lower chord node bundle The material is removed except for the corners, the horizontal brace connects the lower chord nodes of the lower chord plane diagonally, and the lower chord nodes are provided with a unit indirect alloy to connect the adjacent units to the lower chord nodal points. horizontal braces that collectively form a two intersections of the horizontal brace intersection respective extension ends of the horizontal brace horizontal brace intersection that connects to the lower chord node, and the extension line of the lower chord member connecting to lower chord node It is characterized in that the local bending moment generated between the lower chord member and the intersection of the lower chord member and the stiffener at which the extension line of the stiffener connected to the lower chord node intersects is eliminated.

With the above configuration, the bundle material attached between the upper chord node and the lower chord node in the conventional truss is omitted, and the number of members attached to the joint is reduced. As a result, in particular, the joining detail of the lower chord node can be simplified, and the degree of processing of the joining portion can be reduced. However, if the number of members attached to the joint is reduced, the stress generated in the entire truss structure is redistributed and the truss weight increases. Therefore, the horizontal brace connected to the upper node is moved to the lower node. In this way, the compressive stress from the horizontal brace is added to the compressive stress of the upper chord material, and the conventional truss, which had to deal with a larger compressive stress, is made into a unit truss, which reduces the weight of the member and joins as described above. The increase in member weight due to the reduction in the degree of processing of the part is offset. In other words, although the weight of the members that make up the unit truss has increased due to the simplification of the joints of the unit truss, the position of the horizontal brace of the unit truss has been moved from the upper chord surface to the lower chord surface, so that the total weight of the unit truss has increased or decreased. It became clear that there was almost none. As a result, the material cost for weight clearing for the unit truss has hardly increased or decreased, and the processing cost for the unit truss has been reduced due to the improved details of the unit truss. The total cost, which is the sum of the material cost and the processing cost, has been reduced.

In addition, the unit truss removes the bundle material that connects the upper chord node and the lower chord node, so that the intersection of the horizontal braces that gather at the lower chord node, the intersection of the stiffeners that connect to the lower chord node, and the lower chord node. It is preferable to eliminate the local bending moment generated between the intersections of the lower chord members connected to the above. Thereby, the local bending moment occurring under the string node disappears, lower chord member, diagonal member, the member weight, such as horizontal braces are reduced.

Further, it is preferable that the unit truss eliminates the notch for forming the bundle material penetration portion provided in the gusset plate of the lower chord node by removing the bundle material connecting the upper chord node and the lower chord node. .. As a result, the processing cost of providing the notch in the gusset plate can be reduced, and the weight of the joint can be reduced by reducing the thickness of the gusset plate.

Also, the unit truss, the unit indirect alloys thereof which is connected to the gusset plate in the lower chord node is preferably also serve as stiffeners for the plate buckling gusset plates. As a result, the weight of the joint can be reduced by reducing the thickness of the gusset plate.

Also, the unit truss is on the connecting portion between the wall panel and the shed small wall panels attached to the wall independently vertically, J-type connection hardware is preferably used. As a result, the weight of the joint can be reduced by using special hardware suitable for connecting the wall panels to each other.

Also, the unit truss, in units junction, angle member for connection with the J-shaped connecting hardware and horizontal braces are used at the ends, the unit junction at the central portion, the channel member is preferably used .. As a result, the weight of the joint can be reduced by using the unit indirect alloy suitable for connecting the J-type connecting hardware and the horizontal brace in the right place.

Also, the unit truss, during transportation, parapet support material is attach unit, placed at the bottom of the unit parapet support is not possessed, when the stacking units each other attach the parapet support vertically, parapets support It is preferable that the sides to which the roofs are attached are arranged in opposite directions so that one unit does not come into contact with the other unit. As a result, by removing the position of the parapet support material so that it does not come into contact with the adjacent unit, damage or deformation of the parapet support material can be avoided, and the loading can be carried out within the height limit stipulated by the Road Traffic Act. Can fit.

Further, in the unit truss, it is preferable that any of the upper chord member, the lower chord member, and the diagonal member constituting the unit truss is made of thin sheet lightweight shaped steel. As a result, the weight of the constituent members of the unit truss itself can be reduced by using a thin plate lightweight shaped steel that is efficient.

As described above, according to the unit truss according to the present invention, by simplifying the joints detailing dominate the manufacturing cost of the entire unit truss, to provide a unit truss to reduce the overall production cost Can be done.

Further, according to the unit truss according to the present invention, relative to the weight gain of the truss structure by simplifying the joints detail described above, thereby reducing the stress generated in the truss structure to reduce the increase in weight, overall it is possible to provide a unit truss with cost advantage.

It is a perspective view which shows the schematic structure of one Embodiment of the unit truss which concerns on this invention. It also shows the stress generated in the unit truss when a load is applied. It is a front view, a plan view, and a side view of the unit truss of FIG. It is explanatory drawing which shows one division method of the unit of a unit truss. It is explanatory drawing and plan view which show the member structure of a unit truss, and one joint detail of a lower chord node. It is a perspective view which shows one joint detail of the lower chord node of a unit truss. It is a top view which shows the joint detail of the upper chord node of a unit truss. It is a side detailed view which shows the structure of the upper chord lumber, the lower chord lumber, and the diagonal lumber which omitted the bundle material of a unit truss. It is a perspective view which shows the unit truss and one joint part of a shed wall panel and a wall panel, and is explanatory drawing which compares and shows the joint part of the shed small wall panel and a wall panel of a conventional truss, and a unit truss. It is explanatory drawing which shows one Example of the transport method of a unit truss. It is explanatory drawing and plan view which show the member structure of the conventional truss, and the detail of the lower chord material joint part corresponding to FIG. It is a perspective view which shows the detail of the lower chord node joint part of the conventional truss corresponding to FIG.

(Unit configuration)
Hereinafter, the schematic configuration of one embodiment of the unit truss 1 according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of one embodiment of the unit truss 1 according to the present invention. FIG. 1A shows a unit 1A in which a parapet (not shown) is provided on the upper portion of the gable side 32, so that the parapet support member 31 is attached to the truss structure. Further, a reinforcing diagonal member 11 is provided on the structural surface of the connecting member 9 and the stiffener 10. This connecting material 9 also serves as a purlin. Further, FIG. 1B shows a unit 1B when the parapet support member 31 is attached to the truss structure because there is a parapet (hereinafter, not shown) to which the roof finishing material is attached to the upper part of the flat side 33. FIG. 1C shows the unit 1C when there is no parapet and only the parapet support member 31 is at the bottom. As described above, in the unit truss 1, the unit 1C is used as the basic unit of the truss structure, and various members such as the parapet support member 31 are attached to the truss structure according to the design conditions such as the appearance, equipment, and design of the building. Further, in the embodiment of the unit truss 1, these units 1A, 1B, and 1C are combined to form a roof structure, but the roof structure is not limited to these units 1A, 1B, and 1C. A plurality of units 1C may be combined to form a roof structure.

This unit truss 1 is characterized in that a roof panel divided into units 1A, 1B, and 1C is manufactured at a factory, transported to a construction site, and attached to a roof surface at the construction site. It is a truss system used for buildings such as office buildings and factories.

FIG. 2 shows a front view, a plan view, and a side view of the unit truss 1 of FIG. 2 (a) is a front view, FIG. 2 (b) is a plan view, and FIG. 2 (c) is a side view. In FIG. 2C, a reinforcing diagonal member 11 is attached. As the lower structure of the unit truss 1, thin plate lightweight shaped steel is used, but the lower structure is not limited to this, and other lower structures such as a steel frame structure, a reinforced concrete structure, and a wooden structure may be used. The roof finishing material is basically a folded plate roof as a standard, but the roofing material is not limited to this, and other roofing materials such as a concrete roof via a deck plate, a membrane roof, and the like may be used. Ceramic siding is standard for the outer wall, but the outer wall is not limited to this, and other outer wall materials such as ALC board, block, and brick may be used.

(Member composition of unit truss)
The basic member structure of the unit truss 1 is an upper chord member 2a, a lower chord member 2b, a diagonal member 4, and a horizontal brace 5. Conventionally, in the truss 1', the bundle material 6'existed as described later, but it was deleted by the present invention. Further, in the conventional truss 1', the horizontal brace 5 is provided on the upper chord surface as described later, but has been moved to the lower chord surface according to the present invention. As shown in FIG. 1, the horizontal braces 5 on the lower chord surface intersect in an X shape. Further, in the parallel chord truss composed of the upper chord member 2a, the lower chord member 2b, and the diagonal member 4, the adjacent parallel chord trusses are connected to each other by the connecting member 9 and the stiffener 10. The connecting member 9 is a member that also serves as a purlin on the roof surface and connects the upper chord nodes 3a to each other, and the stiffener 10 is a member that connects the lower chord nodes 3b to each other. The diagonal member 4 connects the upper chord node 3a and the lower chord member 2b of the parallel chord truss and the stiffener 10.

As shown in FIGS. 2B and 2C, the main structural members constituting the unit truss 1 are connected to the upper chord member 2a, the lower chord member 2b, the diagonal member 4, and the horizontal brace member 5. It is composed of a material 9 and a stiffener 10. Note that the parapet support member 31 shown in FIGS. 1 (a) and 1 (b) may be attached to FIG. 2. Further, the support material of the cabin wall panel 28 may be attached to the side view shown in FIG. 2 (c). Since the roof is provided with a water gradient as shown in the side view of FIG. 2C, the lower chord member 2b is horizontal, whereas the upper chord member 2a is inclined so as to allow rainwater to flow toward the back surface of the building. (Indicated by an arrow in FIG. 2A). In FIG. 2A, the gradient is 1/100. Further, as shown in FIG. 2A, the unit truss 1 is carried into the construction site in units of units 1A, 1B, and 1C to connect the other units 1A, 1B, and 1C at the construction site. Two of the upper chord member 2a and the lower chord member 2b on both side surfaces of the units 1A, 1B, and 1C will overlap after being installed in the field. Due to the upper chord member 2a and the lower chord member 2b at both ends, the shape of each unit 1A, 1B, 1C of the unit truss 1 is stabilized at the time of carrying in, and the joining accuracy at the site is improved. The diagonal lumber 4 may be referred to as a lattice lumber.

FIG. 3 is an explanatory diagram showing a method of dividing the unit truss 1 into units 1A, 1B, and 1C. FIG. 3A is an example of a building in which parapets are installed on the gable side 32 and the flat side 33. FIG. 3B is an example of a building in which no parapet is installed. These buildings are examples of being built on a corner lot where the front road 34a and the side road 34b intersect. The case where there is a parapet is a case where the parapet support member 31 is provided from the units 1A and 1B as shown in FIGS. 1A and 1B. This is because when the unit truss 1 is used in a building with a design such as a commercial facility, rainwater drainage equipment such as folded plate roofs, ventilation equipment, air conditioning equipment, and gutters installed on the roof from the outside, especially from the entire surface or side of the building. This is to make a blindfold.

(First improvement in unit truss)
The member structure of the unit truss 1 shown in FIG. 4 (a), the joining details of the lower chord member 2b of the unit truss 1 shown in FIG. 5, the member structure of the conventional truss 1'shown in FIG. 10 (a), and FIG. Compare with the joint detail of the lower chord member 2b'of the conventional truss 1'shown in. Then, the weight of the truss member and the degree of truss processing are analyzed.

First, the member configuration of the unit truss 1 shown in FIG. 4A is compared with the member configuration of the conventional truss 1'of FIG. 10A. Here, the conventional truss structure is referred to as "conventional truss 1'". Then, it will be described in comparison with the "unit truss 1" which is one of the prior arts of the present invention. The member numbers constituting the conventional truss 1'are distinguished by adding a dash to the member numbers of the unit truss 1.

The first improvement of the unit truss 1 is that the bundle member 6'connecting the upper chord node 3a and the lower chord node 3b is omitted. As a result, the number of members gathering at the truss intersections of the upper chord node 3a and the lower chord node 3b, which are the intersections of the upper chord member 2a and the lower chord member 2b, is reduced.

Here, the structural roles of the upper chord member 2a', the lower chord member 2b', the diagonal member 4', and the bundle member 6'in the conventional truss 1'are organized as truss members. FIG. 1 (d) shows a stress diagram generated in the truss member by a simple beam model when an evenly distributed load is loaded on the conventional truss 1'. The upper chord member 2a'and the lower chord member 2b'cooperate with each other and resist the bending moment (M) generated in the conventional truss 1'by the bending rigidity. As shown in FIG. 1 (b), assuming that the distance between the upper chord member 2a'and the lower chord member 2b' is the depth (D), the depth (D) of the conventional truss 1'is changed from the maximum depth (Dmax) to the minimum depth (Dmax). It changes up to Dmin). As a result, the axial force (F) generated in the conventional truss 1'is the bending moment (M) / depth (D) at the member positions of both the upper chord member 2a'and the lower chord member 2b'.

On the other hand, the diagonal member 4'resists against the shearing force (S) generated in the conventional truss 1'. The bundle 6'supports a concentrated load from the roofing material that mainly acts on the conventional truss 1'. In addition, it supports the reaction force from the lower structure of the conventional truss 1'. That is, at those concentrated load points, the bundle member 6'provided in the same vertical direction as the concentrated load has a role of dispersing local stress. Further, the upper chord member 2a'and the lower chord member 2b'also have a role of holding the depth (D) at that position. Further, in a wooden truss, in a structural form such as a how truss or a fink truss, a triangular member 4'and a bundle member 6'are formed into a triangle to provide structural stability. With such a flow, the bundle member 6'other than the concentrated load point is provided as a member for bundling the upper chord member 2a'and the lower chord member 2b'at a regular pitch. In addition, Patent Document 2 and Patent Document 4 show the member configurations of Howtras and Finctras.

Therefore, omitting this bundle member 6'from the conventional truss 1'means that stress is redistributed to the constituent members of the truss, and the stress flowing in the conventional truss 1'flows to other members. .. As a result, each member of the unit truss 1 tends to increase in size and the total weight tends to increase. For example, according to a trial calculation on the roof of a certain building, it is reported that the truss weight increases by about 10%.

(Second improvement in unit truss)
The second improvement of the unit truss 1 is that the horizontal brace 5'provided on the upper chord surface is moved to the lower chord surface. 4 (a) and 4 (b) are explanatory views and plan views showing the joining details of the lower chord member 2b of the unit truss 1. 10 (a) and 10 (b) are explanatory views and plan views showing the configuration of the conventional truss 1'and the joining details of the lower chord member 2b' corresponding to FIG. Conventionally, the role of the horizontal brace 5'in the truss 1'is to resist the seismic force input in the horizontal direction with horizontal rigidity, and to flow the generated seismic force of the hut to the ground through the wall structure or the like. Therefore, originally, the horizontal brace 5'is the same as a horizontal resistance element regardless of whether it is on the upper chord surface or the lower chord surface. However, when the horizontal brace 5'is arranged on the upper chord surface closer to the roof surface where the seismic force is generated, the bending moment (M) locally generated due to the distance between the roof surface and the upper chord surface is smaller. Therefore, it has been customary to arrange the horizontal brace 5'on the upper chord surface.

The load conditions for the case where the horizontal brace 5'is arranged on the upper chord surface in the conventional truss 1'and the case where the horizontal brace 5 is arranged on the lower chord surface in the unit truss 1 are arranged. In a long-term load, the stress generated is the compressive force of the upper chord member 2a and the tensile force of the lower chord member 2b. There are cases where a snow load is added to the long-term load, a blow-down due to a wind load is added to the long-term load, and a seismic force is applied to the long-term load in the horizontal direction via the horizontal brace 5. In some cases, the stress generated is the compressive force of the upper chord member 2a and the tensile force of the lower chord member 2b. When a wind load blows up during a short-term load, a tensile force is generated in the upper chord member 2a and a compressive force is generated in the lower chord member 2b, but the tensile force generated in the upper chord member 2a is a long-term load. It is reduced by the compressive force generated by. Therefore, there is a problem when the seismic force is loaded on the upper chord member 2a, which generates a compressive force during a long-term load, in a direction in which the compressive force is applied via the horizontal brace 5. As described above, when the horizontal brace 5 is attached to the upper chord surface, the weight of the truss member tends to be heavier than when the horizontal brace 5 is attached to the lower chord surface.

As described above, in response to the increase in the weight of the members constituting the unit truss 1 due to the simplification of the joint, which is the first improvement of the unit truss 1, the horizontal brace 5 which is the second improvement of the unit truss 1 By moving the position of the unit truss 1 from the upper chord surface to the lower chord surface, it became clear that there was almost no increase or decrease in the total weight of the unit truss 1. As a result, the material cost for weight settlement of the unit truss 1 hardly increases or decreases, and the processing cost of the unit truss 1 is reduced by the details improved by the first improvement point of the unit truss 1. The total cost, which is the sum of the material cost and the processing cost, has been reduced.

FIG. 5 is a perspective view showing the joining details of the lower chord node 3b of the unit truss 1. FIG. 5 shows, in particular, the connection between the units 1A, 1B, and 1C in the intermediate portion of the unit truss 1. The gusset plate 27 to which the horizontal brace 5 is attached is provided with a unit indirect alloy 13 made of a channel material for joining the pre-installed units 1A, 1B, 1C and the post-installed units 1A, 1B, 1C. The unit indirect alloy 13 is provided with screw holes 38 for the pre-installed units 1A, 1B, 1C and screw holes 38 for the post-installed units 1A, 1B, 1C in two rows. The post-installation units 1A, 1B, and 1C are carried to the construction site with the unit indirect alloy 13 attached at the processing factory. Then, the unit indirect alloy 13 is screw-fixed to the pre-installed units 1A, 1B, and 1C, and the connection is completed. As a result, the labor of screwing the units 1A, 1B, and 1C at the construction site is halved. The joint between the units 1A, 1B, and 1C at the end of the unit truss 1 is shown in FIG. 8 of the present specification. The joining detail of the lower chord node 3b of the conventional truss 1'corresponding to FIG. 5 is shown in the perspective view of FIG. Since the bundle member 6'shown in FIG. 11 was deleted in the unit truss 1 of FIG. 5, the notch 14'of the gusset plate 27' could be omitted, and only the unit indirect alloy material 13 was provided at the lower chord node 3b. Further, the joint portion between the upper chord member 2a and the lower chord member 2b does not generate a local bending moment.

(Other details of the unit truss)
FIG. 6 shows the joint details of the upper chord node 3a of the unit truss 1 in a plan view. In the conventional truss 1', the horizontal brace 5'was connected to the upper chord node 3a', but in the unit truss 1, the horizontal brace 5 moved to the lower chord node 3b. Therefore, only the upper chord member 2a and the connecting member 9 are connected to the upper chord node 3a. In this way, the joining detail of the first chord node 3a has also become extremely simple.

FIG. 7 is a detailed side view showing the configurations of the upper chord member 2a, the lower chord member 2b, and the diagonal member 4 from which the bundle member 6'of the unit truss 1 is omitted. Since the bundle member 6'is omitted, the upper chord member 2a and the lower chord member 2b are connected by the diagonal member 4. In this way, since the bundle material 6'is omitted, both the upper chord node 3a and the lower chord node 3b have simple details.

As described above, the first improvement and the second improvement of the unit truss 1 cancel each other out the total weight of the unit truss 1, and the manufacturing cost of the entire unit truss 1 does not change much. However, by simplifying the joint details, which account for most of the manufacturing cost of the unit truss 1, the processing cost of the joint of the unit truss 1 is reduced. On the other hand, the processing cost of the member of the unit truss 1 is almost the same. Therefore, the unit truss 1 has an overall cost merit.

FIG. 8 shows a joint portion between the unit truss 1 and the cabin wall panel 28 and the wall panel 23. FIG. 8A is a perspective view of a joint portion between the unit truss 1 and the cabin wall panel 28 and the wall panel 23. The cabin wall panel 28 and the wall panel 23 are shown by broken lines in FIG. 8 (a). As shown in FIG. 8A, the cabin hut wall panel 28 is a small wall vertical frame 24 that vertically connects the cabin upper frame 18, the cabin lower frame 25, the cabin upper frame 18, and the cabin lower frame 25. It is an outer wall panel supported by a frame formed with. In FIG. 8A, a frame composed of a cabin upper frame 18, a cabin lower frame 25, and a small wall vertical frame 24 is described at a position separated from the unit truss 1 for easy understanding. On the other hand, the wall panel 23 is installed at the lower part of the cabin lower frame 25. As shown in FIG. 8C, a connecting hardware 16 is used for the J-shaped connecting hardware 12 in the field for connecting the cabin wall panel 28 and the wall panel 23.

FIG. 8B is an explanatory view showing a joint portion between the conventional truss and the cabin wall panel 28'and the wall panel 23'. FIG. 8 (c) is an explanatory view showing a joint portion between the unit truss 1 and the cabin wall panel 28 and the wall panel 23, which corresponds to FIG. 8 (b). As shown in FIG. 8B, in the conventional truss 1', the joint between the cabin wall panel 28'and the wall panel 23' receives the reaction force from the horizontal brace 5', so that a plurality of general shaped steels are used. As a result, the details were complicated. Further, the fixing of the screw 35'that joins the hut hut wall panel 28'and the wall panel 23' was poor workability because the work was performed upward from under the wall of the hut hut wall 25'. As shown in FIG. 8 (c), in the unit truss 1, the joining between the cabin wall panel 28 and the wall panel 23 was able to simplify a complicated cross section by utilizing the J-shaped connecting metal fitting 12. .. Further, the fixing of the screw 35 for joining the cabin wall panel 28 and the wall panel 23 is a downward work from above, so that the workability is improved. In this way, the details of the joint, which was a complicated cross section in the conventional truss 1', have been eliminated and the workability has been improved. Further, the workability was improved by joining the cabin wall panel 28'and the wall panel 23', which had poor workability with the conventional truss 1', by screwing from the upper part.

(Transporting method of unit truss)
FIG. 9 is an explanatory diagram showing an embodiment of a method for transporting the unit truss 1. The unit truss 1 manufactured at the factory is loaded on a transport vehicle 36 such as a truck, fixed by a rack 37, and carried to a construction site. The loading method to the transport vehicle 36 will be described. FIG. 9 shows an example in which the unit 1A and the unit 1B with the parapet and the unit 1C without the parapet are stacked one above the other and loaded on the transport vehicle 36. As described above, the unit truss 1 may have a parapet support member 31 attached to the unit truss 1. In this case, the problem is how to safely transport a large number of units 1A, 1B, 1C. Therefore, the units 1A, 1B, and 1C to which the parapet support member 31 is attached are arranged alternately in the front-rear direction to avoid damage or deformation of the parapet support member 31. In addition, by removing the position of the parapet support member 31 so as not to contact the units 1A, 1B, 1C adjacent to the upper side, a larger number of units 1A can be kept within the height limit specified by the Road Traffic Act. , 1B, 1C can be safely transported. In this way, by removing the position of the parapet support member 31 so as not to contact the adjacent units 1A, 1B, 1C, damage or deformation of the parapet support member 31 can be avoided, and the load is regulated by the Road Traffic Act. It can fit within the height limit. As a result, the transportation efficiency of the unit truss 1 can be improved and the transportation cost can be reduced.

Further, any one of the upper chord member 2a, the lower chord member 2b, and the diagonal member 4 constituting the unit truss 1 is made of thin sheet lightweight shaped steel. This thin plate lightweight shaped steel is formed of a thin plate having a thickness of 3 mm or less. As a result, the weight of the constituent members themselves of the unit truss 1 can be reduced by using an efficient thin sheet lightweight shaped steel.

The configuration, shape, size, and arrangement relationship described in the above embodiments are only schematically shown to the extent that the unit truss 1 of the present invention can understand and implement them. Therefore, the present invention is not limited to the described embodiment, and can be changed to various forms as long as it does not deviate from the scope of the technical idea shown in the claims.

1 unit truss, 1A (with parapet support material only on the gable side) unit, 1B (with parapet support material only on the flat side) unit, 1C (no parapet mounting material on either side) unit, 1'conventional truss, 2a upper chord material, 2'upper chord material, 2b lower chord material, 2'lower chord material, 3a first chord node, 3a'upper chord node, 3b lower chord node, 3b'lower chord node, 4 parapet, 4'parapet, 5 horizontal brace, 5 ´ Horizontal brace, 6 ´ Bundle material, 9 connecting material, 10, 10 ´ Stiffening material, 11 Reinforcing diagonal material, 12 J type connecting hardware, 13, 13 ´ Unit indirect alloy, 14 ´ Notch, 16 For connecting Hardware (angle material), 18 small wall upper frame, 19', 19a', 19b'horizontal brace intersection, 20'stiffening material intersection, 21'structural core, 22,22'bundling material penetration, 23,23'wall Panel, 24 small wall vertical frame, 25,25'small wall lower frame, 26 unit indirect alloy, 27,27' gusset plate, 28,28' hut small wall panel, 31 parapet support, 32 gable, 33 Flat side, 34a front road, 34b side road, 35, 35'screw, 36 transport vehicle, 37 rack, 38 screw holes, D depth, Dmax maximum depth, Dmin minimum depth, F axial force, M bending moment, S shear force ..

Claims (2)

A flat truss is formed by an upper chord member connecting the upper chord nodes, a lower chord member connecting the lower chord nodes, and a diagonal member connecting the upper chord node and the lower chord member, and the upper chord node of the adjacent flat truss is formed. A unit truss in which a connecting member for connecting the two, a stiffener for connecting the lower chord nodes of the adjacent flat truss, and a horizontal brace provided only on the lower chord surface form a three-dimensional truss.
Wherein the top chord node is to assemble the upper chord member and the connecting member is, the the lower chord node is to assemble the lower chord member and the stiffener, Tabazai connecting the upper chord nodes and the lower chord nodes are , Except for the corners, the horizontal brace diagonally connects the lower chord nodes on the lower chord surface.
A unit indirect alloy is provided at the lower chord node to connect adjacent units.
The horizontal braces to set the lower chord nodes, each extension line between two of the horizontal brace intersect to form an intersection of the horizontal brace, the horizontal brace intersections to be connected to the lower chord nodes, and wherein Local bending that occurs between the intersection of the lower chord member and the stiffener at which the extension line of the lower chord member connected to the lower chord node and the extension line of the stiffener connected to the lower chord node intersect. A unit truss characterized by extinguishing moments. The unit truss according to claim 1, wherein the unit indirect alloy material also serves as a stiffener against plate buckling of a gusset plate to which a channel material is connected.

Images