JPH03228936A - Truss bridge and construction method therefor - Google Patents

Abstract

PURPOSE:To ensure the light weight of a truss bridge by jointing a lower chord member and a pillar to each other with an inner slant member, constituting either of the chord member and the slant member with a pre-stress introduction member, and providing a jack and a pin connection part on a part of the members for the rigid connection thereof after erection. CONSTITUTION:The lower chord member 4 of a long-span horizontal or angled truss beam 2 and pillars 1 at both ends thereof are connected with inner slant members 1B. Also, one of the upper chord member 3 and lower chord member 4 of the truss beam 2, and the inner slant member 1B is constituted with a pre-stress introduction member. Furthermore, a jack is provided on a part of the main structural members of the chord and slant members, and so constituted as to be freely slidable in a lengthwise direction. Also, a pin connection part and an unassembled part are provided on a part of the main structural members. After the predetermined load is applied, the connection parts are rigidly jointed. According to the aforesaid construction, a truss beam can be made lightweight.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a long span truss frame and a method for constructing the same.

(Prior art) A truss frame with a long span is constructed by rigidly connecting a horizontal truss beam (b) to a pair of vertical columns (a) as shown in Fig. 24, or by rigidly connecting a horizontal truss beam (b) to a pair of vertical columns (a) as shown in Fig. 25. As such, the vertical column (a)
It is constructed by rigidly joining an angle-shaped truss beam (b') onto (a).

In the figure, (c) is the upper chord member of the truss beam, (d) is the lower chord member,
(e) is a connecting material between the upper and lower chord members.

Therefore, when introducing prestress to the frame, the second
In the frame shown in Figure 4, generally a wire such as a tension wire (f) is stretched between the columns (a) along the lower chord (d), and the wire (f) is taut to connect the column (a). A method has been adopted in which the prestress is fixed in the lower chord member (d) in the compression direction as shown by the arrow.

Furthermore, in the frame shown in Fig. 25, a truss beam (b) is rigidly connected to a pair of columns (a) (a) with external diagonals (g). Before joining the truss beam (b), apply an upward load P to the truss beam (b).
The external diagonal member (
A method is used in which prestress in the tensile direction is introduced into the external diagonal member (g) by rigidly joining the lengths of the members g).

(Problems to be Solved by the Invention) However, in the conventional frame shown in Fig. 24, a large amount of tension wires equal to (length of truss beam) x (number of truss beams) is required. The conventional frame shown in the figure has a problem in that the amount of steel used increases due to the provision of external diagonal members.

Furthermore, since the conventional prestress introduction method shown in Figs. 24 and 25 causes forcible deflection of a rigid frame, a powerful loading means is required, and at the same time, the use of such a loading means improves construction efficiency. There is a problem in that it poses a danger.

The present invention was proposed in view of the problems of the prior art, and its purpose is to make it possible to construct a truss frame that is lighter and has a longer span than before, and to enable the construction of a truss frame with a small load. The object of the present invention is to provide a truss frame capable of effectively and safely introducing prestress into structural members, and a method for constructing the truss frame.

(Means for Solving the Problems) In order to achieve the above object, a truss frame according to the present invention has a horizontal or chevron-shaped truss beam with a long span, and columns that support both ends of the truss beam, The pillar is vertically inclined from the foundation or inwardly upward, and the upper end of the main column is connected to the end of the truss beam, and the main column is inclined inwardly and upwardly from near the lower end of the main column. and an internal diagonal member whose upper end portion is joined to the lower chord member of the truss beam.

According to a second aspect of the present invention, in the truss frame, any one of the main structural members consisting of the upper chord member, the lower chord member of the truss beam, and the internal diagonal member of the column is constituted by a prestress introducing member.

According to the invention of claim 3, in the step of constructing the truss frame, when introducing prestress to the main structural member, a part of the main structural member is configured to be slidable in the longitudinal direction of the member, A predetermined load in the tensile or compressive direction is applied to the member by a jack interposed in the longitudinal direction of the member across the sliding part, and in this state, the sliding part is They are rigidly connected to each other.

As described above, when introducing prestress into the main constituent members of the truss frame, the invention according to claim 4 makes the central part of one of the upper and lower chord members of the truss beam a pin joint part, and The member between one node at the center of the chord member is in an unassembled state, both ends of the beam are rigidly connected to a pair of opposing columns, and an upward load is applied near the center of the truss beam. Under this condition, the unassembled member corresponding to one node is interposed in the center interval of the other chord member, and the member is rigidly joined to the other chord member.

Furthermore, the invention of claim 5 is such that the lower end of the column is rigidly connected to the foundation in an unassembled state with the members for one node connecting between the column and the truss beam, and the company installs building materials on the same column. Both ends of the truss beam are connected with pins, a predetermined upward load is applied near the center of the truss beam, and under this condition, the unassembled members between the one node are attached to the column and the truss beam. It is a rigid joint.

(Function) As described above, in the truss frame according to the present invention, the columns extend from the vicinity of the lower end of the main column connected to both ends of a horizontal or chevron-shaped truss beam with a long span, to the inner upper side of the main column. By providing an internal diagonal member slanted to It works to reduce the span.

Therefore, compared to other types of truss frames with equal column spacing, the weight of the truss beam can be further reduced, or if the weight cannot be reduced, the span can be further increased.

According to the invention of claim 2, in the truss frame according to the invention, any one of the upper chord member, the lower chord member, and the internal diagonal member of the column is used as a prestress introduction member, so that the weight of the truss beam is reduced by the weight of the truss beam. Since the function of suppressing deflection is produced, the weight of the truss frame can be reduced or a frame with a larger span can be constructed.

According to the invention of claim 3, a part of the main constituent members of the upper and lower chord members of the truss beam and the inner and outer diagonal members of the column are configured to be slidable in the longitudinal direction of the member, and the main constituent members of the upper and lower chord members of the truss beam and the inner and outer diagonal members of the column are configured to be slidable in the longitudinal direction of the members, and the By applying a predetermined load in the tensile or compressive direction to the member through a jack interposed in the longitudinal direction on the member, the sliding parts are brought into rigid contact with each other, thereby achieving compact load loading. By this means it is possible to introduce a safe and large prestress into the component.

According to the invention of claim 4, the span center part of one of the upper and lower chord members of the truss beam is used as a pin joint part, and the member between one node of the span center part of the other chord member. In an unassembled state, both ends of the truss beam are rigidly connected to a pair of columns to form a temporary pin structure frame, and in this state, an upward load is applied near the center of the span of the truss beam. Because of the loading, the rigid structure consisting of truss beams and columns on both sides of the pin joint easily deflects upward due to a small upward load, compared to the case where the pin joint was not provided.

As mentioned above, when the stress applied to the truss beam chord of the pin structure reaches a predetermined value due to the upward applied load, the above-mentioned one-node distance is applied to the interval at the center of the span of the other chord. By interposing the unassembled member of the frame and rigidly connecting it to the other chord member, and then removing the upward load, the truss frame changes from a temporary pin structure to a stable rigid structure, and The required prestress is introduced into the structural member.

According to the invention of claim 5, the lower end of the column is rigidly connected to the foundation with the members for one node to be connected between the column and the truss beam in an unassembled state, and the building material is installed on the company. By pin-joining both ends of a truss beam with a rigid structure, a frame with a pin structure that is prone to deflection is formed. In this state, by applying an upward load near the center of the span of the truss beam, a small load causes deflection, and a predetermined stress is applied to the chord members of the truss beam. Under this condition, the above 1.
By aligning the lengths of the unassembled members between the nodes between the columns and beams, rigidly connecting them, and then removing the upward load, the frame can be stabilized from the -0 time bottle structure. This results in a rigid structure and introduces the necessary prestress into the structural members of the frame.

(Example) The present invention will be described below with reference to the illustrated embodiments.

FIGS. 1 and 2 show an embodiment of the present invention, in which both ends of a long-span chevron-shaped truss beam (2) are rigidly connected to opposing columns (1) (1).

In the figure, (3), (4), and (5) are the upper chord members, the lower chord members, and the connecting members that connect the upper and lower chord members of the slat beam (2).

The above-mentioned companies (1) are each rigidly connected to the foundation, are oriented vertically or inwardly upward, and are slightly inclined, and have their upper ends connected to the above-mentioned truss beams (
The main pillar (18) rigidly connected to the end of 2) and the main pillar (l^) from above the foundation that touches one end of the main pillar (IA)
It is composed of an internal diagonal member (IB) that is inclined upwardly and inwardly and is rigidly connected to the end of the truss beam (2).

In the embodiment shown in FIG. 1, a case is shown in which the main pillar material (IA) is slightly inclined inward.

FIG. 2 is a plan view of a long span building using the truss frame shown in FIG. 1 as a structural member, erected at predetermined intervals in the row direction, and connected by girders and diagonal members.

Figures 3 to 7 show other embodiments of the truss frame, and Figures 3 and 4 show the main columns (1^) inwardly inclined, and the angle-shaped truss beam (2a) and the horizontal truss beam. A case in which (2b) is combined is shown.

Figures 5, 6, and 7 show the case where the main column (IA) is arranged vertically and combined with different angle-shaped truss beams (2c) (2d) and horizontal truss beams (2e). shows.

According to the embodiment, the load on the truss beam (2) is transmitted to the foundation via the main column (IA) and the inner diagonal member (IB), so that Compared to the conventional truss frame shown in Fig. 1, when the spacing between the building materials of columns (1) and (1) is equal, the main column members (LA) and internal diagonal members (IB
) will reduce the span of the truss beam (2). Therefore, the weight of the truss beam can be reduced by this substantial span reduction, and construction materials can be saved.

On the other hand, in exchange for weight reduction, a longer truss frame becomes possible.

Furthermore, according to the present invention, the upper chord member (3), the lower chord member (4), and the column (1) of the truss beam (2) in the truss frame
It introduces prestress into any of the main structural members, such as the internal diagonals (IB) of the

20 and 21 show the prestress introduction means for the main structural member, and (6) in the figure shows the upper chord member (3).
, a lower chord member (4), or an external diagonal member (7), a part of which is cut and removed in advance, and a pair of opposing structural members (6A )(6
A predetermined gap (8) is formed between the cut surfaces of B). Between the opposing end faces of both structural members (6A) (6B), one end is inserted and fixed into one structural part tt (6a:+), and the other end is inserted into the other structural member (6B) and fixed to the telescope tube 2. Interpose the inserted sleeve (9).

A plurality of spacers (11) are interposed between the flanges (IOA) (IOB) provided on the outer peripheral surfaces of opposite ends of the twin structural members (6A) (6B), and each flange (IOA)
(IOB) with bolts, and both structural members (6^) (6B) are connected via the spacer (11). Furthermore, a plurality of jacks are interposed between the flanges (IOA) and (IOB).

After setting the prestress introducing means configured as described above on a part of the structural member (6) and constructing the above-described truss frame, the spacer (11) is removed and the jack 02
) is extended or shortened to a predetermined length, and the sleeve (9) and the structural member (6B) side are welded together, thereby introducing a required amount of tension or prestress in the compressive direction to the structural member (6). , which constitutes a truss frame with a more stable structure.

Note that the joint near the jack of the prestress introduction part described above can be constructed by various other methods, such as cutting the structural member (6) in advance, elongating or shortening it with jacks, and then applying that state. Any configuration that can be rigidly joined is sufficient.

8 to 13 show other embodiments of the method of the present invention. In FIG. 8, when assembling the truss frame shown in FIG. The lower end of the column (1) consisting of is placed above the bottle joint 0■ on the foundation, and the span center of the lower chord member (4) of the truss beam (2) is set at the bottle joint 0. At the center of the span, the chord members and connecting members between one node (hereinafter referred to as key member 05) are left unassembled, and both ends of the truss beam (2) are attached to the main column members (IA ) with rigid joints on top.

Here, the pin joint 04) refers to a joint that includes a joint using a pin that can rotate within the structural plane of the frame and a joint structure that has the same rotational deformation ability as the pin, such as a deformation ability. In some cases, they are connected by members with .

In the above state, the truss frame has a pin structure that can undergo rotational deformation at the pin joint portion 04. Under this condition, an upward load P is applied to the vicinity of the center of the truss beam (2) by pushing it up with a jack or by lifting it with a crane, and for example, the allowable deflection amount of the truss beam (2) is applied to the lower chord (4). The 9th
As shown in the figure, the length of the unassembled key member 05) is adjusted between the contact points at the center of the span of the upper chord member (3), and it is rigidly joined to the unjoined upper chord member (3).

Note that the upward load P can be applied while monitoring changes in tension of the lower chord member (4) and the internal diagonal member (IB) via a strain gauge or the like.

Figures 22 and 23 show an example of the case where the length of the key member 05) is adjusted and rigidly connected to the upper chord member (3). (5) is the connecting member at the center of the span of the beam whose upper end is left unjoined, 0ω
is a connecting girder plate welded to the upper end of the connecting material (5),
07) is the reinforcing face material for the upper edge of the same girder plate 0ω, and O mark is the upper chord material (
A slit provided in the unjoined end side of 3) so that the connection girder plate 06) is loosely fitted, 09) shown by the dotted line in FIG.
is the on-site welding performed at the end of length adjustment.

By joining the key member 09 in this way, the truss frame, which used to be a pin structure, changes to a stable and rigid structure, and the required prestress is created in the internal diagonal member (IB) and the lower chord member (4). It will be in the installed state.

The pin joint portion 041 and the key member surface may be provided upside down, and in the case of this method, the joint portion on the foundation at the lower end of the column may be either a rigid joint or a pin joint.

According to this method, when the frame is in the pin structure state during construction, sufficient deflection and internal stress can be easily generated in the member by applying a small upward load, and in this state, the key member By rigidly connecting two truss beams between the nodes of the truss beam, it is possible to easily introduce the required prestress and construct a rigid truss frame.

10 and 11, and FIGS. 12 and 13 show cases in which the conventional truss frames shown in FIGS. 24 and 25 are constructed in the same manner as described above. Parts equivalent to those in the embodiment are given the same reference numerals.

FIGS. 14 and 15 show other embodiments of the method of the present invention, and FIG. 14 shows an unassembled state in which the internal diagonal member is set as a key member 0ω when assembling the truss frame shown in FIG. The lower end of the main pillar (IA) is rigidly connected to the foundation, and both ends of the rigid truss beam (2) are attached to the upper end of the main pillar (IA) using pin joints 00. In this state, the truss frame is a pin structure that can undergo rotational deformation at the pin joint 00. Under this state, an upward load P is applied near the center of the span of the truss beam (2). ) with the required amount of deflection and stress. Under this condition, the internal diagonal member (IB) constituting the key member 05)
) are fixed in length and rigidly connected to the truss frame.

In this way, by rigidly joining the key members with zero length, that is, the internal diagonal members (IB), the truss frame changes from a temporary pin structure to a stable rigid structure as shown in Fig. 15, and the internal diagonal members (IB) are rigidly connected. IB) is introduced with a prestress in the compressive direction that counteracts the gravitational deflection of the truss beam (2).

16 and 17 show the conventional truss frame shown in FIG. 24 with the external diagonal member being key member 00.
Similar to the construction method shown in Figure 5, the truss frame is temporarily made into a pin structure, and in this state an upward load P is applied, and the pin member is 0ω.
, that is, the case where the external diagonal member is rigidly connected to the truss frame is shown.

In addition, FIGS. 18 and 19 show the conventional truss frame shown in FIG. 24 in the same process as above, using the outermost node of the lower chord member (4) of the truss beam (2) as key member 051. The figure shows the case of erection. In either case, the frame is temporarily made into a pin structure during assembly, and an upward load is applied in a state where it is easily bent, making it possible to easily introduce a predetermined prestress with a small load. ,
Thereafter, the length of the key member 05) is adjusted and rigidly connected to the truss frame to complete the erection of the frame, thereby improving work efficiency and ensuring safety.

(Effects of the Invention) According to the truss frame according to the present invention, as described above, the columns supporting both ends of the truss beam are inclined vertically or inwardly upward from the foundation, and the upper end is joined to the end of the truss beam. The interior of the truss beam is made up of a main column with a truss beam, and an internal diagonal member that slopes upward from the inside of the main column from near the lower end of the main column, and whose upper end is joined to the lower chord of the truss beam. The beam length support point of the diagonal members reduces the actual span length of the truss beam, making the truss beam of the truss frame lighter than before, or making it possible to construct a truss frame with a longer span than before. .

The invention according to claim 2 provides the following advantages: by introducing prestress into either the chord member of the truss beam or the internal diagonal member of the column,
This makes it easier to reduce the weight of the truss frame and increase its length.

The invention according to claim 3 is configured such that a part of the structural member made of the chord members and column constituent members of the truss beam in the truss frame is configured to be slidable in the longitudinal direction of the member, and the member is moved across the sliding portion. A predetermined axial load is applied to the member by means of a jack interposed above in the longitudinal direction, and under this condition, the sliding parts are rigidly connected to each other, and prestress is introduced into the member. This allows for the construction of a truss frame with a long span.

The invention according to claim 4 provides a method in which the center part of one of the upper and lower chord members of the truss beam is made into a pin joint part, and the member between one node in the center part of the other chord member is in an unassembled state. , both ends of the beam are rigidly connected to a pair of opposing columns to make it easy to bend during the construction of the truss frame, and under this condition an upward load is applied near the center of the truss beam. By rigidly joining the unassembled members at one node in the center of the truss, the required prestress can be easily introduced into the structural members of the truss frame with a small upward load. This allows a rigid truss frame to be erected in a safe process.

The invention according to claim 5 provides a method for connecting the truss beam and the column.
The members between the nodes are in an unassembled state, the lower end of the column is rigidly connected to the foundation, and the building material is placed on the truss beam. By rigidly joining the unassembled members for one node between the column and the truss beam under a condition where a predetermined upward load is applied near the center of the Prestress can be easily introduced, and a rigid truss frame can be erected in a safe process.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the truss frame according to the present invention, Fig. 2 is a plan view thereof, and Figs. 3 to 7 each show other embodiments of the truss frame according to the present invention. Front view, Figures 8 and 9, Figures 10 and 1
1, 12 and 13, 14 and 15,
16 and 17, FIG. 18 and FIG. 19 are front views showing the steps of each embodiment of the method for constructing a truss frame according to the present invention, and FIG. 20 is a front view showing the prestress introducing means, Figure 21 is the arrow view XXI-XXI in Figure 20,
Fig. 2 is a front view showing a state in which the key member is rigidly connected to the middle part of the upper chord member of the truss beam, and Fig. 23 is a view taken from arrow XXI- in Fig. 22.
FIG. XXIII, FIG. 24, and FIG. 25 are front views showing conventional truss frames, respectively. (1) Column (IA) Main column member (IB) Internal diagonal member (2) Truss beam (3) Upper chord member (4) Lower chord member (6)
(6A) (6B)... Structural member, (7)... External diagonal member. (9)...S IJ-F, (11)...
·Spacer. (12)...Jaze, (13)...
Pin joint. (14)...Pin joint, (15)...Key member. (16)...Pin joint.

Claims (1)

[Claims] 1. It has a horizontal or chevron-shaped truss beam with a long span, and columns that support both ends of the truss beam, and the columns are inclined vertically or inwardly upward from the foundation, and the upper end is a main column joined to the end of the truss beam, and an internal slope that is inclined upwardly inward from the main column from near the lower end of the main column, and whose upper end is joined to the lower chord of the truss beam. A truss structure characterized by being constructed of wood. 2. It has a horizontal or chevron-shaped truss beam with a long span and a column that supports both ends of the truss beam, and the column is inclined vertically or inwardly upward from the foundation, and the upper end is attached to the end of the truss beam. The truss beam is composed of a joined main column and an internal diagonal member that is inclined upwardly inward from the main column from near the lower end of the main column and whose upper end is joined to the lower chord of the truss beam. A truss frame characterized in that any one of the upper chord member, lower chord member, and internal diagonal member of a beam is constructed from a prestress introduction member. 3. When constructing a long-span truss frame that has a horizontal or chevron-shaped truss beam and columns that support both ends of the truss beam, the main structural members of the upper and lower chord members of the truss beam and diagonal members that constitute the columns are Either of the members is configured such that a part of the member is slidable in the longitudinal direction of the member, and the member is pulled by a jack interposed in the member in the longitudinal direction across the sliding portion. Alternatively, a method for constructing a truss frame comprising applying a predetermined load in a compression direction and rigidly joining the sliding parts to each other under this state. 4. When constructing a long-span truss frame that has a horizontal or chevron-shaped truss beam and columns that support both ends of the truss beam, the central part of one of the upper and lower chord members of the truss beam is A pin joint is used, and the part between one node in the center of the other chord member is in an unassembled state, and both ends of the beam are rigidly connected to a pair of opposing columns, and the part near the center of the truss beam is With an upward load placed on it, under this condition,
The method is characterized in that the unassembled member corresponding to the one node is interposed in the central interval of the other chord member, the member is rigidly joined to the other chord member, and then the upward load is removed. How to erect a truss frame. 5. When constructing a long-span truss frame that has a horizontal or chevron-shaped truss beam and columns that support both ends of the truss beam, it is necessary to remove members for one node connecting between the column and the truss beam. In the assembled state, the lower end of the column is rigidly connected to the foundation, the column is installed as a building material, both ends of the truss beam are connected with pins on the column, and a predetermined upward load is applied near the center of the truss beam. In this state, the unassembled members between the one node are rigidly connected to the column and the truss beam, and then the upward load is removed.