JP4801471B2 - Single layer lattice dome structure - Google Patents

Description

  The present invention relates to a single-layer latticed dome structure for constructing a dome-shaped truss frame roof formed of a plurality of lattice members and node members on an upper part of a concrete cylindrical wall.

  As shown in FIG. 10, the single-layer lattice dome structure 101 is configured by assembling a horizontal lattice 103 and an oblique lattice 104 in a single-layer network via a nodal member 102, and the lattice dome against an out-of-plane load. The members (horizontal lattice 103 and oblique lattice 104) are resisted by the in-plane force (axial force). The node member 102 joins the lattice materials 103 and 104 together.

In the conventional single-layer lattice dome structure 101, the horizontal lattice material 103a at the lowermost stage (the outermost periphery in FIG. 10) is a tension ring 106 that resists a vertical downward load on the dome with a tensile axial force (for example, a patent). Reference 1). That is, in the conventional single-layer lattice dome structure 101, the tension ring 106 resists by replacing the horizontal reaction force generated by the out-of-plane load of the single-layer lattice dome structure 101 with the axial force of the horizontal lattice material 103a (tension ring 106). The overall structure was self-balancing.
JP 2001-303667 A

  In the conventional single-layer lattice dome structure 101, the lowermost horizontal lattice material 103a is used as the tension ring 106. Therefore, in order to balance the out-of-plane rigidity of the upper lattice dome portion dynamically, the cross section of the tension ring 106 is usually The cross section of the upper horizontal lattice material 103 or the oblique lattice material 104 is two to three times. For this reason, even if an attempt is made to reduce the weight by using an aluminum alloy lattice dome, the weight of the tension ring 106 increases, resulting in an increase in the overall weight and an increase in cost.

  Further, in the above configuration, the radial displacement accompanying the change in the axial length of the tension ring 106 cannot be completely suppressed. For this reason, the single-layer lattice dome structure 101 cannot be pin-supported, and the geometric nonlinearity of the dome structure accompanying radial displacement is one of the factors that determine the yield strength of the single-layer lattice dome structure 101. That is, if the axial rigidity of the member corresponding to the tension ring 106 at the lowermost part of the single-layer lattice dome structure 101 can be increased, the proof strength of the dome can be increased.

  Therefore, the present invention has been devised to solve the above-described problem, and an object thereof is to provide a single-layer lattice dome structure capable of increasing the axial rigidity of the lowermost portion.

  Therefore, the present inventors, when the cylindrical wall constituting the dome housing structure is made of concrete such as reinforced concrete or prestressed concrete, the strength of the cylindrical wall is sufficiently large and only increases the amount of reinforcing bars. Therefore, the above-mentioned problem can be solved by omitting the tension ring and giving the cylindrical wall body the function of the tension ring.

That is, the invention according to claim 1 for solving the above-described problem is a simple construction for constructing a dome-shaped truss frame roof body formed of a plurality of lattice members and node members on an upper part of a concrete cylindrical wall body. In the layered lattice dome structure, the nodal member located at the lowest stage of the dome-shaped truss frame roof is joined to the inner peripheral side of the upper end of the concrete frame portion of the cylindrical wall body. .

  Here, the concrete cylindrical wall body refers to a cylindrical wall body having a concrete frame portion constructed of reinforced concrete or prestressed concrete.

  According to the above configuration, since the concrete frame portion that can easily form a large cross section can be used as the tension ring, the axial rigidity of the tension ring portion at the lowermost stage (periphery) of the dome-shaped truss frame roof body can be increased. Can improve the yield strength. Therefore, when the required proof strength of the dome is equal, the member can be made thinner than the conventional dome-shaped truss frame roof body, and weight reduction and cost reduction can be achieved.

The invention according to claim 2 is characterized in that the lowermost node member is joined to a position lower than the upper end on the inner peripheral side of the concrete casing portion of the cylindrical wall body . It is a single layer lattice dome structure.

In the invention according to claim 3, a chamfered portion having a surface perpendicular to the axial direction of the lattice material joined to the lowermost node member is formed on the inner peripheral side of the upper end portion of the concrete casing portion. The single-layer lattice dome structure according to claim 1 or 2, wherein

According to the said structure, while being able to transmit the load of a dome-shaped truss frame roof body efficiently to a cylindrical wall body, it becomes structurally advantageous and it is easy to perform joining construction.

  ADVANTAGE OF THE INVENTION According to this invention, the axial rigidity of the lowest step part of a dome-shaped truss frame roof body can be improved, and the yield strength of a dome can be improved. Therefore, when the required proof stress is equal, a member can be made thinner than the conventional dome-shaped truss frame roof body, and weight reduction and cost reduction can be achieved.

(First embodiment)
The best mode for carrying out a single-layer lattice dome structure according to the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, a case where a water storage tank or the like having a cylindrical wall body made of reinforced concrete formed in a cylindrical shape is described as an example.

  FIG. 1 is an overall sectional view showing a first best mode for carrying out a single layer lattice dome structure according to the present invention, and FIG. 2 is a first best view for carrying out a single layer lattice dome structure according to the present invention. FIG. 3 is a plan view showing a node member for connecting a lattice material, and FIG. 4 is an enlarged sectional view of a main part showing a first best mode for implementing a single-layer lattice dome structure. FIG. 5 is an enlarged view of an essential part showing a first best mode for implementing the single-layer lattice dome structure. 4 is a cross-sectional view taken along the line XX shown in FIG. Further, FIG. 5 is an arrow view of the cylindrical wall body as viewed from obliquely upward on the outer side, as indicated by the white arrow in FIG. 4.

  As shown in FIGS. 1 and 2, the single-layer lattice dome structure 1 according to the present invention is configured by constructing a dome-shaped truss frame roof body 20 on an upper portion of a concrete cylindrical wall body 10. The dome-shaped truss frame roof body 20 is formed of a plurality of lattice members 30 and a node member 50 that connects the lattice members 30 to each other. The lattice material 30 is divided into a horizontal lattice material 31 extending in the horizontal direction and an oblique lattice material 32 extending in the inclination direction. The horizontal lattice material 31 is connected so as to form a plurality of concentric rings in a plan view.

  As shown in FIGS. 4 and 5, the lattice material 30 of the present embodiment is made of, for example, an extruded shape member 33 made of aluminum or aluminum alloy, and has an H-shaped cross section. The extruded shape member 33 is arranged with the web 33b upright so that the flanges 33a on both sides of the web 33b are positioned above and below the web 33b. Note that the lattice material 30 is not limited to the extruded shape member 33 made of aluminum or aluminum alloy, and H-shaped steel made of steel or other members or alloys such as stainless steel or titanium may be used. Good. Further, wood may be used, and the shape is not limited to the H-shaped cross section, and for example, a round pipe, a square pipe, or a solid rod shape may be used.

  As shown in FIG. 4, the node member 50 includes a node member 51 positioned at the lowest level of the dome-shaped truss frame roof body 20 and other node members 52 at the upper part excluding the node member 51 at the lowest level. It consists of types.

  As shown in the upper right part of the plan view of FIG. 3 and the cross-sectional view of FIG. A hub 53a and a lower hub 53b are provided. The upper hub 53a is joined to the upper flange 33a of the lattice material 30 via a plurality of bolts 54a and nuts 54b, and the lower hub 53b is connected to the bottom of the lattice material 30 via a plurality of bolts 54a and nuts 54b. It is joined to the side flange 33a. The upper hub 53a and the lower hub 53b are formed by processing so that the peripheral portions thereof are parallel to the axial direction of the lattice material 30 that is disposed so as to be inclined with respect to each other.

  The upper hub 53a and the lower hub 53b are made of aluminum or an aluminum alloy similarly to the lattice material 30, and improve the aesthetics by unifying the texture with the same surface finish as the lattice material 30. Yes. Needless to say, the surface finish, material or color of the node member 52 may be changed from that of the lattice material 30 to make an accent, thereby enhancing the design.

  As shown in the lower left part of the cross-sectional view of FIG. 4 and the plan view of FIG. 5, the lowermost node member 51 in the present embodiment is a V-shaped plan view of two oblique lattice members 32 of the lattice member 30. It is a member joined in a shape. The node member 51 is formed in a U-shaped cross section when viewed from the side, and an upper anchor hub 55b and a lower anchor hub 55c are provided at both ends in the vertical width direction of the base plate 55a fixed to the cylindrical wall body 10. It is comprised by welding. Between the upper anchor hub 55b and the lower anchor hub 55c, the end portion of the oblique lattice material 32 is inserted so as to contact the upper and lower flanges 33a and 33a. The upper anchor hub 55b is joined to the upper flange 33a of the oblique lattice member 32 via a plurality of bolts 54a and nuts 54b, and the lower anchor hub 55c is attached to the oblique lattice via a plurality of bolts 54a and nuts 54b. The lower flange 33a of the member 32 is joined.

  The node member 51 is made of aluminum or an aluminum alloy like the lattice material 30, and the appearance is improved by unifying the texture with the same surface finish as the lattice material 30. Needless to say, the surface finish, material, or color of the node member 51 may be changed from that of the lattice material 30 to make an accent, thereby improving the design.

  As shown in FIG. 4, the cylindrical wall body 10 is constructed of, for example, a reinforced concrete structure, and has a concrete casing portion 11 constructed in a cylindrical shape. Various reinforcing bars such as the vertical wall bars 12a, the horizontal wall bars 12b, and the width stop bars 12c are arranged in the concrete frame portion 11. Here, up to a predetermined distance from the upper part of the concrete frame part 11, for example, a range of 500 mm, the arrangement pitch of the horizontal wall bars 12 b and the width stopper bars 12 c is made smaller than the normal wall part (lower wall part), Muscle mass is increased. In order to increase the amount of reinforcement, the diameter of reinforcing bars such as the vertical wall bars 12a and the horizontal wall bars 12b extending in the circumferential direction of the wall may be increased.

  As described above, the dome-shaped truss frame roof body 20 formed of the plurality of lattice members 31 and 32 (30) and the node members 51 and 52 (50) has the lowest node member 51 as the cylindrical wall body 10. It is being fixed to the cylindrical wall body 10 by joining to the concrete frame part 11 of this.

  A chamfered portion 14 having a surface 13 inclined so as to be orthogonal to the axial direction of the oblique lattice member 32 joined to the lowermost node member 51 is formed on the inner peripheral side of the upper end portion of the concrete casing portion 11. A steel buried 15 is embedded in a portion of the surface 13 of the chamfered portion 14 where the node member 51 is joined. The buried metal 15 is embedded so that the surface thereof is flush with the surface 13 of the chamfered portion 14. The buried metal 15 has a surface area equal to or larger than that of the base plate 55 a of the lowermost node member 51. A plurality of anchor bolts 16 are welded and fixed to the back surface of the buried metal 15. The anchor bolt 16 is formed so as to be inserted inside the lateral wall stripe 12b to obtain a predetermined fixing length. The buried metal 15 is buried at the same time when the concrete casing 11 is placed.

  A plurality of (three in the present embodiment) stud bolts 17 are welded and erected on the surface of the buried metal 15. The stud bolts 17 are arranged at a predetermined interval in the circumferential direction of the cylindrical wall body 10 (see FIG. 5). Bolt holes 57 of the stud bolts 17 are formed in the base plate 55a of the lowermost node member 51. A plurality of stud bolts 17 are respectively passed through the bolt holes 57 to set the node members 51, and the nuts 18 are screwed into the respective stud bolts 17, so that the node members 51 do not rotate with respect to the concrete casing portion 11. To be joined.

  In FIG. 4, 21 (denoted by a two-dot chain line) represents a roof exterior material, and 22 (denoted by a two-dot chain line) represents a ledge supporting the roof exterior material 21. Reference numeral 23 (denoted by a two-dot chain line) denotes a connection cover for the roof surface material 21 and the pressing edge 22. The roof surface material 21 and the pressing edge 22 are fixed to the lattice material 30 via a garter material (not shown). The roof surface material 21 and the pressing edge 22 are formed to extend to the outer peripheral surface portion of the concrete frame portion 11. The connection cover 23 is fixed to the upper part of the node member 52 via a fixing member (not shown).

  According to the present embodiment, as described above, the nodal member 51 located at the lowest stage of the dome-shaped truss frame roof body 20 is joined to the concrete frame portion 11 of the cylindrical wall body 10, thereby providing a concrete frame portion. 11 can have the function of a conventional tension ring. Therefore, since it is not necessary to provide a tension ring, the corresponding lattice material can be omitted, and the single layer lattice dome structure 1 can be reduced in weight and cost.

  Moreover, since the concrete housing | casing part 11 can comprise a big cross section easily, the axial rigidity of the circumferential direction of the cylindrical wall body 10 can be improved. Specifically, the axial rigidity is expressed by E · A (E: Young's modulus, A: cross-sectional area), but the Young's modulus of the concrete casing 11 is inferior to the Young's modulus of the conventional metal tension ring. However, the cross-sectional area of the concrete housing portion 11 can be significantly larger than that of the tension ring. Therefore, when the concrete casing 11 is used instead of the tension ring, the shaft rigidity can be made much larger than when a general tension ring is used. Further, in order to increase the shaft rigidity, the size of the member has been increased in the past, which has led to a significant weight increase. However, in the concrete frame portion 11, it is easy to increase the amount of reinforcing bars. Can be reinforced.

  As described above, the reinforced strength of the dome-shaped truss frame roof body 20 itself can be enhanced by the high axial rigidity of the concrete frame portion 11 to which the lowest node member 51 is connected. Therefore, when the required proof stress is equal, each lattice material 30 can be made thinner than the conventional dome-shaped truss frame roof body, and weight reduction and cost reduction can be achieved. Moreover, since the concrete housing part 11 has high axial rigidity, the concrete housing part 11 hardly changes in axial length, and the radial displacement can be suppressed almost completely.

  Furthermore, in the present embodiment, the dome-shaped truss frame roof body 20 is fixed in contact with the inclined surface 13 of the chamfered portion 14, so that the load of the dome-shaped truss frame roof body 20 is cylindrical. It can be efficiently transmitted to the wall 10 and it is structurally advantageous, and it is easy to perform joining.

(Second embodiment)
FIG. 6 is an enlarged cross-sectional view of a main part showing a second best mode for implementing a single-layer lattice dome structure, and FIG. 7 is a main part showing a second best mode for implementing a single-layer lattice dome structure. It is an enlarged plan view.

  In the present embodiment, a new dome-shaped truss frame roof 20 'is constructed on the upper part of a water storage tank made of an existing reinforced concrete tubular wall 10' formed in a cylindrical shape without a roof. The case where the concrete casing portion 11 ′ of the cylindrical wall body 10 ′ has sufficient axial strength as a tension ring will be described as an example.

  As shown in FIGS. 6 and 7, the nodal member 51 ′ located at the lowermost stage of the dome-shaped truss frame roof body 20 ′ is a base plate that comes into contact with the inner peripheral surface of the concrete frame portion 11 ′ of the cylindrical wall body 10 ′. 56a and a pair of gusset plates 56b and 56c attached to the base plate 56a. The node member 51 'is made of aluminum or an aluminum alloy.

  Each of the gusset plates 56b and 56c is made of an extruded shape having a U-shaped cross section when viewed from above, and is configured to sandwich the web 33b of the oblique lattice material 32 to be joined. The pair of gusset plates 56b and 56c are arranged in a V shape in plan view along the axial direction of the oblique lattice member 32 to be joined. The gusset plates 56b and 56c are fixed to the base plate 56a by welding. The oblique lattice material 32 is joined to the node member 51 ′ by sandwiching the web 33 b of each oblique lattice material 32 between the gusset plates 56 b and 56 c and fastening with the plurality of bolts 54 a and nuts 54 b. The base plate 56a has a substantially square rectangular shape when viewed from the front. A plurality of bolt holes 57 are formed in the base plate 56a. The bolt holes 57 are formed at four positions on the left, right and top and bottom positions when viewed from the front, avoiding the fixing positions of the gusset plates 56b and 56c.

  On the other hand, an outer base plate 40 is provided on the outer peripheral surface of the concrete casing portion 11 ′ at a position corresponding to the node member 51 ′. The outer base plate 40 has the same shape as the base plate 56 a and has four bolt holes 57. The outer base plate 40 is made of aluminum, an aluminum alloy, steel, or the like, and the material is not limited as long as it has a required strength.

  A bolt hole 19 penetrating in the wall thickness direction is formed in the concrete casing portion 11 ′. The bolt hole 19 is formed in the existing cylindrical wall body 10 ′ avoiding the reinforcing bars by on-site construction. The bolt holes 19 are formed according to the positions of the bolt holes 57 of the base plate 56 a and the outer base plate 40.

  Anchor bolts (fixed bolts) 22 are inserted into the bolt holes 57 of the base plate 56a, the bolt holes 19 of the concrete casing portion 11 ′, and the bolt holes 57 of the outer base plate 40, and both ends thereof are tightened with nuts 23, The nodal member 51 ′ is fixed to the concrete frame portion 11 ′. At this time, since the anchor bolts (fixing bolts) 22 are provided at four locations on the top, bottom, left, and right as viewed from the front of the base plate 56a, the node members 51 'are joined to the concrete frame portion 11'.

  Since other configurations are the same as those of the first embodiment, the same reference numerals are given in the drawing, and the illustration is omitted.

  According to such a structure, even if it is the existing cylindrical wall body 10 ', the node member 51' can be joined with a simple structure and simple construction. And since the role of a tension ring can be given to the concrete housing | casing part 11 'with high axial rigidity, the effect similar to 1st embodiment can be acquired.

(Third embodiment)
FIG. 8 is an enlarged cross-sectional view of a main part showing a third best mode for implementing a single-layer lattice dome structure, and FIG. 9 is a main part showing a third best mode for implementing a single-layer lattice dome structure. It is an enlarged plan view.

  In the present embodiment, a new dome-shaped truss frame roof 20 ′ is constructed on the upper part of a water storage tank made of an existing reinforced concrete tubular wall 10 ″ formed in a cylindrical shape without a roof. The case where the concrete casing portion 11 ″ of the cylindrical wall 10 ′ does not have sufficient axial strength as a tension ring will be described as an example.

  As shown in FIGS. 8 and 9, the node member 51 ″ located at the lowermost stage of the dome-shaped truss frame roof body 20 ′ is the same as that of the second embodiment, and includes a base plate 56a and a pair of gusset plates 56b. 56c. In the present embodiment, the second embodiment is that a ring-shaped reinforcing member 41 is provided on the outer peripheral surface of the concrete casing portion 11 ″ to which the lowermost node member is joined. It is different from the form. Since other configurations are the same as those of the second embodiment, the same reference numerals are given and description thereof is omitted.

  The reinforcing member 41 is made of channel steel having a U-shaped cross section, aluminum alloy, or the like. The reinforcing member 41 is bent in accordance with the curvature of the outer peripheral surface of the cylindrical wall body 10 ″, and is arranged so that the back surface portion of the web 43 abuts on the outer peripheral surface of the cylindrical wall body 10 ″. Bolt holes 58 are formed in the web 43 at four locations. The bolt hole 58 is formed at a position corresponding to the bolt hole 57 formed in the base plate 56a.

  Anchor bolts (fixed bolts) 22 are inserted into the bolt holes 57 of the base plate 56 a, the bolt holes 19 of the concrete casing 11 ′, and the bolt holes 58 of the reinforcing member 41. The member 51 "is fixed to the concrete housing part 11". At this time, since the anchor bolts (fixing bolts) 22 are provided at four locations on the top, bottom, left, and right as viewed from the front of the base plate 56a, the node member 51 "is joined to the concrete frame portion 11".

  According to such a configuration, even with an existing cylindrical wall body 10 ″ that does not have axial rigidity as a tension ring, it is possible to reinforce the concrete frame portion ”with a simple configuration and simple construction. The node member 51 "can be joined. The concrete casing 11" which is reinforced and has increased axial rigidity can be given the role of a tension ring. Similar effects can be obtained.

  Although the best mode for carrying out the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately changed in design without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the lowermost node members 51, 51 ′, 51 ″ of the dome-shaped truss frame roof bodies 20, 20 ′, 20 ″ are bolted to the concrete frames 11, 11 ′, 11 ″. Although it joins using it, even if it joins by other means, such as welding, the same effect can be acquired.

  In the above-described embodiment, the cylindrical wall bodies 10, 10 ′, 10 ″ have been described as being constructed of reinforced concrete. However, the present invention is not limited to this. The cylindrical wall bodies 10, 10 ′. , 10 ″ may be made of concrete, and may have a concrete frame portion made of a prestressed concrete structure, a steel reinforced concrete structure, or a precast concrete plate.

It is the whole sectional view showing the 1st best form for carrying out the single layer lattice dome structure concerning the present invention. It is the whole top view showing the 1st best form for carrying out the single layer lattice dome structure concerning the present invention. It is the top view which showed the node member which connects a lattice material. It is the principal part expanded sectional view which showed the 1st best form for implementing a single layer lattice dome structure. FIG. 5 is a diagram showing a first best mode for carrying out a single-layer lattice dome structure, as shown by a white arrow in FIG. FIG. It is the principal part expanded sectional view which showed the 2nd best form for implementing a single layer lattice dome structure. It is the principal part enlarged plan view which showed the 2nd best form for implementing a single layer lattice dome structure. It is a principal part expanded sectional view which showed the 3rd best form for implementing a single layer lattice dome structure. It is the principal part enlarged plan view which showed the 3rd best form for implementing a single layer lattice dome structure. It is the top view which showed the conventional single layer lattice dome structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Single layer lattice dome structure 10 Cylindrical wall 10 'Cylindrical wall 10 "Cylindrical wall 11 Concrete frame part 11' Concrete frame part 11" Concrete frame part 16 Anchor bolt 22 Anchor bolt 30 Lattice material 41 Reinforcement member 50 Node Member 51 (bottommost) node member

Claims (3)

In the single-layer lattice dome structure that constructs a dome-shaped truss frame roof formed by a plurality of lattice members and node members on the upper part of the concrete cylindrical wall body,
A single-layer latticed dome structure characterized in that a nodal member located at the lowest stage of the dome-shaped truss frame roof is joined to the inner peripheral side of the upper end portion of the concrete frame portion of the cylindrical wall. 2. The single-layer latticed dome structure according to claim 1, wherein the lowermost node member is joined to a position lower than an upper end on an inner peripheral side of a concrete casing portion of the cylindrical wall body . The chamfered portion having a surface orthogonal to the axial direction of the lattice material joined to the lowermost node member is formed on the inner peripheral side of the upper end portion of the concrete frame portion. The single-layer lattice dome structure according to claim 2.

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