KR102564471B1 - Composite lattice girder bridge assembled in warren truss shapes - Google Patents

Abstract

An object of the present invention is to enable a composite girder having a conventional truss structure shape to be applied not only to railway bridges but also to long-span road bridges with a wide bridge width while maintaining the ratio of the mold height applied to existing composite girder bridges .
To this end, in the present invention, a composite lattice girder bridge of a new structural type adopting a direction-dependent hinge structure in which the currently generated in-plane moment is not transmitted to the inclined member, but the out-of-truss moment and the axial load of the inclined member are transmitted. It became.
In addition, in the present invention, in order to reduce the size of the inclined member, the inclined member is arranged to form a Double Warren truss. A bonding method was applied in which the processed inclined members are butted together.
As a result, it is possible to greatly increase the applicable span length of the conventional steel-concrete composite girder without increasing the height of the girder to the level of the truss bridge, and it is possible to rapidly increase the installation of formwork and supports for concrete deck construction. It has the advantage of being easy to construct.

Description

Composite lattice girder bridge assembled in warren truss shapes}

The present invention relates to a composite lattice girder bridge in which a truss-shaped composite lattice girder and a concrete floor plate made of half precast concrete panels are combined, and more particularly, each component of a composite lattice girder manufactured in a factory is used at a bridge construction site. It relates to a long-span prefabricated composite lattice girder bridge that can be easily assembled using welding and high-strength bolts.

Composite type bridges are typical of constructing a concrete floor plate that directly resists the load of a vehicle after first fabricating the main girders at a factory or at a bridge construction site, mounting the manufactured girders on top of piers using a temporary device such as a crane, and then constructing a concrete floor plate that directly resists vehicle loads. Go through the process. In this series of construction processes, the dwelling derder must have structural performance capable of resisting not only its own weight, but also additional fixed loads due to the construction of the floor plate and protective walls, and then various working loads such as vehicle loads.

However, in long-span bridges where the bridge span length exceeds 60m, the cross-sectional force caused by the fixed loads such as the girder, concrete deck, and bridge pavement and barriers is much larger than the cross-sectional force caused by the fluctuating load such as vehicle load. In this case, it is necessary to lighten the weight of the girder and the weight of the concrete floor plate as much as possible.

As a method of reducing the self-weight of the main rudder, the most effective method is to replace the abdominal member, which is mainly made of walls that resist shear force, with a truss member in which compressive force and tensile force act alternately. However, it is assumed that the truss members can resist only axial force and are connected to each other through an ideal hinged junction that cannot resist moment. ) is known to be less than 10. In other words, in order to construct a truss type bridge with a span length of 70m, the height of the main girder must exceed 7m.

However, the mold height of truss bridges is very low compared to the mold height of typical composite girder bridges between 15 and 25, so the conventional truss bridge is mainly used in the form of a bridge through which trains or vehicles pass over the lower chord of the truss. In general, the shape of the cross-section also has the shape of a rectangle with two perpendicular planes parallel to each other. Since around 1990, in the construction of some railway bridges in Europe, Japan, and Korea, a number of bridges have been built in the form of a bridge over which trains or vehicles pass by constructing a concrete deck on top of the upper chord, but all of these bridges have cross sections It has a square shape. Moreover, in the case of some bridges, despite having a cross-sectional shape protruding out of the truss surface in the form of protruding a part of the concrete floor plate, the bridge width could not be greatly increased, and the height ratio was much smaller than that of general composite girder bridges. As it retains its characteristics, it has been mainly used only for the construction of railway bridges under extremely limited conditions.

As described above, it is assumed that the junction point of the conventional truss bridge is configured as an ideal hinge in all directions, but when looking at the shape of the junction point in actual use, it is closer to a rigid structure in which not only axial force but also moment are transmitted simultaneously. However, if the height ratio (L/H) is less than 10, it can approach the ideal truss behavior in which the transmission of force by axial force is dominant. Therefore, the current road bridge design standards stipulate that the maximum height ratio of truss bridges should not exceed 10. . However, it is very rare to have a site condition for constructing a bridge in the form of a bridge that can have a composite action with a concrete deck while keeping the height ratio below 10, so it is very rare to have a truss that can be assumed as an ideal hinge. The construction of road bridges is difficult in practice.

In addition, in the case of a road bridge, the standard width of a two-lane highway bridge is 12.145 to 12.600 meters, and the concrete floor plate and bridge pavement are longer as the span length of the bridge increases due to the reason that the width of the concrete floor plate through which vehicles directly pass is very wide compared to that of railway bridges. The weight of the back acts as the main design variable, and as a result, the specifications (size and thickness) of the truss that serves as the web member rapidly increase. The magnitude of the moment generated at the critical point where the current meets increases, causing a problem that it can no longer be treated as a truss member.

In addition, the cross-section of a composite truss bridge in the form of a conventional upper road bridge had to be a cross-sectional shape in which at least both ends of the concrete deck protruded outward by 3 m or more beyond both edges of the truss girder in order to satisfy the bridge width of 12 m or more required for road bridges. . However, when a vehicle passes through the exposed beam, an absolutely greater bending moment is induced than when passing through the concrete floor plate located between the top chords of the truss girder. Not only does this greatly increase, but additional temporary materials such as large-scale supports and formwork required for constructing the concrete floor plate of the exposed beam part are required, which reduces safety and greatly increases the total construction cost.

The present invention has the form of a conventional truss bridge with excellent openness, while maintaining the ratio (15 to 25) used in general composite girder bridges, and at the same time, it can be easily applied to road bridges with a bridge width of 12 m or more, and a length of 70 m or more The goal is to provide a new type of composite lattice girder bridge that does not greatly increase the specification of the yarn while maintaining the mold height ratio at 15 or more even if it becomes a span bridge.

Chords (meaning 'upper chord and lower chord') and inclined members of the composite lattice girder according to the present invention are all formed in a continuous rod-shaped cross section, so they behave as beam members capable of resisting axial force and moment. Therefore, when these members are combined into a general rigid frame structure, moment is transmitted in the junction area where the two members are combined, and the magnitude of the moment transmitted to the inclined member depends on the bending stiffness ratio between the chord and the inclined member, the angle of arrangement of the inclined member, etc. determined by

The variable that has the greatest influence on the bending stiffness ratio and the angle of arrangement of the inclined member is the mold height ratio, and when the mold height ratio increases to the level of a general composite girder bridge, the moment generated in the inclined member also increases. Of course, since the appearance of the composite lattice girder bridge according to the present invention has the shape of a conventional truss structure, most of the external load acting on the bridge is transmitted in the form of axial force dominated by the truss action. However, the vertical deflection of the chord made of beams causes a bending moment, which inevitably results in the occurrence of a bending moment in the inclined member when the chord and the inclined member are connected in a rigid structure. Therefore, the only way to remove or reduce the bending moment of the inclined member while increasing the height ratio to the level of general composite girder bridges (15 to 25) is to insert a connecting member with very small bending stiffness between the chord and the inclined member to connect these two members. It is to introduce a similar hinge structure that connects indirectly.

On the other hand, unlike the cross section of the conventional upper chord bridge type composite truss bridge, the gap of the upper chord part facing the chord and the inclined member of the composite lattice girder according to the present invention on the cross section is wider than the bridge width, and the gap of the lower chord part is wider than the bridge width It is tilted at a predetermined angle to make it narrower, and then a stringer is placed in the center of the cross section in the direction of the bridge to create two simple supported spaces, and the upper chord and stringer and lower chord and stringer of the composite lattice girder are placed at both ends. It is connected to each strut made of steel treated to act as a hinge structure to make it three continuous warrent truss shapes in cross section, and precast concrete panels are mounted with upper chords and stringers as support points, and A cast-in-place concrete floor plate is formed using the cast-in-place concrete panel, but the thickness of the precast concrete panel is less than 55% of the total floor plate thickness (the sum of the thickness of the precast concrete panel and the thickness of the cast-in-place concrete floor plate). Through this, it is possible to manufacture a bridge with a bridge width of 12m or more.

In addition, when the span length of a bridge becomes longer, the axial force acting on the inclined member increases and the size of the cross section inevitably needs to be increased. There is a risk of local loss. As a solution to this, if the inclined member is arranged in the shape of a Double Warren truss in the direction of the bridge, the effect of reducing the size of the axial force currently applied in the standard of the inclined member and the junction area by half can be expected. However, in order to arrange the inclined member in the form of a double Warren, a complicated process of cutting each member in advance at the intersection of the inclined member under tension and the inclined member under compression, combining them into a predetermined shape, and then joining them together again by welding is required. have to go through

In the present invention, in order to solve the above manufacturing problems that occur when arranging the inclined member in the form of a double warren, the inclined member is bent while maintaining left-right symmetry so that the center angle is 120 ° or more, and then the bending process is performed. With the outer parts of the two inclined members facing each other, a method in which the axes of the two inclined members are structurally coupled while maintaining a straight line through a process of welding a connecting plate to each of the inclined members is applied.

The present invention can construct a new type of composite lattice girder bridge that can maintain a height ratio similar to that of a general steel-concrete composite girder bridge while having the structural shape and structural characteristics of a conventional truss.

In addition, unlike the conventional upper bridge truss bridge, the effective width of the bridge through which vehicles pass can be freely increased by the size desired by the designer, so it can be used for the construction of road bridges as well as railway bridges with narrow bridge width.

1 is a partially cut perspective view showing a composite lattice girder bridge according to a first embodiment of the present invention.
Figure 2 is a cross-sectional view showing the bridge of Figure 1;
Figure 3a is a perspective view showing the inclined member provided in the bridge of Figure 1;
Figure 3b is a view showing the central angle (θ ₁ ) and the arrangement angle (θ ₂ ) of the inclined member.
Figure 4a is a view showing the coupling structure of the inclined member and the upper chord.
Figure 4b is a view showing the coupling structure of the inclined member and the lower chord.
Figure 5a is a cross-sectional view showing the junction section of the phase chord where the compressive force acts.
Figure 5b is an enlarged view showing the left side of the upper chord of Figure 5a.
Figure 5c is an enlarged view of the AA' section of Figure 5a.
FIG. 5d is an enlarged view of a BB′ section of FIG. 5a.
6 is a cross-sectional view showing a composite lattice girder bridge according to a second embodiment of the present invention.
7a to 7b are cross-sectional views showing the upper and lower chords of the composite lattice girder bridge according to the third embodiment of the present invention and the square tubes forming the inclined members.
8 is a partially cut perspective view showing a composite lattice girder bridge according to a fourth embodiment of the present invention.
Figure 9 is a view showing the connection structure of the inclined member and the upper chord in the composite lattice girder bridge of Figure 8;
10 is a view showing a cantilever part precast concrete panel in the composite lattice girder bridge of FIG.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

1 is a partially cut perspective view showing a composite lattice girder bridge according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a composite lattice girder bridge.

Referring to the drawing, the composite lattice girder bridge 100 is inclined to connect the upper and lower chords 110 and 120, the stringers 130, and the upper and lower chords 110 and 120 extending along the bridge axis direction. The upper strut 150 connecting the upper chord 140, the upper chord 110 and the stringer 130, the inner stud 155 connecting the stringer 130 and the lower chord 120, and the lower chord The lower bracing 160 connecting the 120 to each other, the precast concrete panel 170 installed to be supported by the upper chord 110 and the stringer 130, and the cast-in-place concrete on the precast concrete panel 170 It includes a formed concrete floor plate 175 and the like.

The upper and lower chords 110 and 120 may be made of a steel pipe having a circular or rectangular cross section or an I-shaped open cross section, and the drawing shows upper and lower chords made of a steel pipe having a circular cross section. In the section where the compressive force acts, the inside of the steel pipe of the upper chord 110 can be filled with concrete to increase resistance to local buckling, and this concrete filling can also be applied to the lower chord 120 in the same way. This will be described later.

According to the present invention, the truss surface formed by the upper and lower chords 110 and 120 and the inclined member 140 is tilted outward and arranged so as to form an inverted isosceles trapezoid, and the center of the cross section (the center between the upper chords) Arrange stringers 130 made of steel pipes or H-beams along the bridge direction.

In addition, steel pipe studs 150 and 155 may be used to connect the stringer 130 and both upper chords 110 and to connect the stringer 130 and both lower chords 120. Between the stringers 130 and the currents 110 and 120 may be connected by a hinge structure in which only axial force is transmitted in a cross section. The studs 150 and 155 are preferably installed in a direction perpendicular to the throttling direction.

The connection between the studs 150 and 155 and the currents 110 and 120 is connected in a hinge structure using high-tensile bolts. Specifically, as shown in FIGS. 4A to 4B, the connecting member 152 is installed in the current 110 and 120 and the stringer 130 in a direction perpendicular to the bridge axis, respectively, and the studs 150 and 155 After the connecting plates 151 at both ends are inserted between the connecting members 152, high-tensile bolts (not shown) are fastened. The connection member 152 is a member in which two iron plates are arranged in parallel at a predetermined interval, and a bolt hole is formed to pass through the two iron plates. The connection plate 151 is inserted between the two iron plates and then fastened with high-tensile bolts.

The connecting member 152 is preferably installed in the junction section of the current 110 and 120, and the stringer 130 has a portion corresponding to the junction section (a straight line extending from the junction section in a direction perpendicular to the bridge axis meets the stringer part) is preferred.

The inclined member 140 connects the upper and lower chords 110 and 120 to each other, but is installed so as to be inclined outward. In the drawing, the bent inclined member 140 is shown as forming a double warranty, but the length of the bridge is short or the magnitude of the external applied load is small, so the size of the axial force acting on the inclined member is a commercially available section steel product. If resistance can be sufficiently resisted even with the use of, a warrent truss may be formed by combining straight inclined members (not shown in the drawing) with the upper and lower chords. A joint plate 142 may be coupled to both ends of the straight inclined member, and the joint plate 142 may be coupled between a pair of joint plates 146.

In addition, the inclined member 140 may be made of a steel pipe having a circular cross section as shown in the drawing, but may also be made of a rectangular steel pipe or an H-beam. A joint plate 142 may be coupled to both ends of the square steel pipe and the H-beam, and the joint plate 142 may be coupled between a pair of joint plates 146.

As shown in FIGS. 3A to 3B, after manufacturing the inclined member 140 by bending the central portion of the steel pipe, the connecting plate ( 141) can be used to combine the two inclined members 140. The connecting plate 141 may be manufactured by cutting both sides of the rectangular steel plate in the longitudinal direction to correspond to the bent angle (θ ₁ , central angle) of the inclined member. The side surface is a part that is welded (coupled) to the inclined member 140.

Both ends of the steel pipe are cut so as to be inclined at a certain inclination angle (θ _S in FIG. 5A), and then a rectangular joint plate 142 is welded to the inside of the steel pipe so that a part of the joint plate 142 protrudes out of the steel pipe .

Specifically, from both ends of the inclined member 140, both sides are obliquely cut so that the angle θ _S with the shaft center line 145 along the length direction of the inclined member is 45 ° or less, and the diameter of the inclined member 140 The rectangular joint plate 142 having a width smaller than 2 to 5 mm is coupled to the inner surface of the inclined member 140 in the longitudinal direction of the inclined member (ie, the same angle as the arrangement angle θ ₂ ), but acts on the inclined member. Insert and combine with a length longer than the design axial force or greater welding resistance strength is secured. At this time, the joint plate 142 protrudes outward about 100 to 150 mm from the end of the inclined member 140. Subsequently, the portion cut at the angle θ _S is covered with a flat plate 143 .

In addition, on the upper and lower chords 110 and 120 to which the inclined member 140 is connected, a pair of joint plates 146 are placed at intervals 2 to 3 mm larger than the thickness of the joint plate 142 at the angle (arrangement) of the inclined member By welding in advance in the same direction as the angle (θ ₂ ), inserting the joint plate 142 between the joint plates 146 and welding them together, the truss behaves as a hinge structure for the moment in the in-plane direction, and the moment in the out-of-plane direction For , it behaves as a rigid structure.

Meanwhile, the bonding plate 146 may be supported by installing support plates 147 in front and behind the bonding plate 146 .

In the section where the upper chord 110 receives the tensile force, the inner reinforcing plate perpendicular to the cross section of the upper chord 110 at the position where the upper chord 110 and the inclined member 140 meet (not shown in the drawing. By installing the upper chord (limited to the location where the inclined members meet) inside the upper chord 110, it is possible to prevent damage to the upper chord due to local acupressure and shear stress.

In order to make an accurate Double Warren truss shape through bending, it is preferable to set the angle θ ₂ of the inclined member 140 to 60° to 75° on the surface where the truss is formed. If, when the arrangement angle (θ ₂ ) is smaller than 60° and the shaft center line 145 of the facing inclined member 140 is maintained on the same straight line, the bending radius must be 2.5 times or more than the diameter of the inclined member 140. If the design criterion is not satisfied, and the condition for the bending radius is artificially satisfied, the axis of the inclined member 140 is not placed on the same line, and an additional moment is generated at the junction of the inclined member 140. For reference, in order for the arrangement angle (θ ₂ ) of the inclined member 140 to be 60° or more, the size of the central angle (θ ₁ ) during bending must be 120° or more.

Also, if the arrangement angle θ ₂ exceeds 75°, the number of junctions increases exponentially, which is not preferable.

When the two inclined members 140 bent to satisfy these geometric constraints are brought into contact with each other, the shaft center lines 145 of the facing inclined members 140 are placed on the same line, and FIG. 3B shows the left inclined member ( 140) shows that the lower shaft center line 145 is located on the same line as the upper shaft center line 145 of the right inclined member 140.

In this state, the sides of the connecting plate 141 manufactured to be the same as the radius of curvature at the bent portion of the inclined member 140 are welded to both inclined members 140 so that the two inclined members 140 are structurally perfect. Make the truss move. At this time, the thickness and length of the connecting plate 141 may be determined by the magnitude of the vertical force due to the axial force acting on each inclined member 140 .

FIG. 4A is an enlarged view showing the coupling structure of the inclined member 140 and the upper chord 110, and FIG. 4B is an enlarged view showing the coupling structure of the inclined member 140 and the lower chord 120.

As described above, the mold height of the composite lattice girder according to the present invention is at the same level as the mold height ratio (15 to 25) of general composite girder bridges. The moment in the plane of the truss formed by the inclined member increases and a large moment may be generated in the inclined member, which causes a problem in that the standard of the inclined member must be rapidly increased. On the other hand, if the chord and the inclined member are stiffened in the out-of-plane direction of the truss, a moment is generated in the inclined member, but at this time, the magnitude of the moment is not greatly affected by the height ratio, and the magnitude is also very small compared to the moment in the in-plane direction. Common.

In view of this point, the present inventors have provided a pair of bonding plates 146 to insert the inclined member 140 from the side into the current 110 and 120 to which the inclined member 140 is connected. It is welded in advance to match the arrangement angle (θ ₂ ) of (140).

Then, by inserting the joint plate 142 between the joint plates 146 and then welding it, it behaves as a hinge structure against the moment in the truss in-plane direction, and resists with rigidity against the moment in the truss out-of-plane direction, including torsion. It forms a direction-dependent hinge structure with

5A shows the junction section of the phase chord 110 subjected to compressive force in the composite lattice girder. The inside of the phase chord 110 receiving the compressive force is filled with concrete 119, and the axial force acting on the inclined member 140 causes the axial force of the phase chord 110 in the junction section where these two members meet. Therefore, in order to equally transfer this axial force to the steel and concrete constituting the upper chord 110, first, the shear connector 112 that allows the axial force induced in the steel portion of the upper chord 110 to be distributed to the concrete 119 inside ) is preferably provided.

On the other hand, the transmission of the axial force to the steel part is performed through a pair of joint plates 146 attached to the upper chord 110, and the axial force of the inclined member 140 transmitted to the joint plate 146 causes the upper chord to The steel part of (110) causes local deformation (pressurization or drawing), and if the phase chord 110 is composed of only steel materials, the thickness of the phase chord 110 is equal to or greater than that of the phase chord 110 inside. It can be counteracted by welding a vertical reinforcing plate (installed so as to be perpendicular to the bridge axis. Not shown in the drawing) having a thickness. However, in order to fill the inside of the upper chord 110 with concrete, it is better not to install a vertical reinforcing plate in terms of workability, and moreover, the filled concrete 119 and the steel part of the upper chord 110 can be integrated into one member. If possible, there is no need to install a separate reinforcement plate. To this end, in the present invention, a plurality of head-attached studs 112 capable of sufficiently resisting the horizontal force caused by the axial force of the inclined member 140 in the phase chord 110 subjected to compression are used in the phase chord 110 in the junction section. It is welded to the lower part of the inner surface (the part where the bonding plate is installed).

On the other hand, it is preferable that the length of the steel pipe does not exceed 12 m for smooth concrete filling work inside the steel pipe, and a finishing plate 118 having a thickness of 15 mm or more equipped with a plurality of head-attached studs 113 is welded to both ends of the cut steel pipe. It is desirable to make it integral with the concrete filled inside so that it can resist the compressive force. In addition, concrete filling into the steel pipe can be performed by forming a hole 118a with a diameter of 15 to 20 cm in the center of one end plate 118, and the height of the concrete filling once in the vertical state of the steel pipe exceeds 3 m. It is desirable to perform sufficient internal compaction while not doing so.

Meanwhile, although filling the inside of the upper chord 110 with concrete 119 has been described above, the inside of the lower chord 120 can be filled with concrete even when the lower chord 120 receives a compressive force, The filling method can be made the same as that of the phase current 110, and head-attached studs 112 and 113 can also be installed.

The lower bracing 160 connects the lower chords 120 to each other. The lower bracing 160 is coupled to each other by a connecting plate (161 in FIG. 1) in a state in which the two steel pipes (smaller in diameter than the steel pipe used for the inclined member) are bent and then the bent parts are placed in contact with each other. As a member, it has an 'X' shape.

The joint plate (162 in FIG. 4B) is installed at both ends of the steel pipe, and the joint plate 162 is inserted between the pair of joint plates 166 and then coupled is the same as in the inclined member 140. . However, since the steel pipe has a smaller diameter than the inclined member 140, oblique cutting of both ends can be omitted.
Referring to FIGS. 1, 2 (especially enlarged view), and FIG. 4B , the lower bracing 160 is connected to the lower chord 120 by a direction dependent hinge structure. That is, this direction-dependent hinge structure transmits the axial force of the steel pipe and the moment in the out-of-plane direction of the plane on which the two lower chords 120 are placed between the steel pipe of the lower bracing 160 and the lower chord, and transmits the moment in the in-plane direction of the plane However, this point will be easily understood by those skilled in the art considering that this direction-dependent hinge structure is similar to the direction-dependent hinge structure of the inclined member 140.

Then, below, the construction process of the composite lattice girder bridge 100 will be described.

First, the upper chord 110, the lower chord 120, the inclined member 140, the stringer 130, the upper strut 150, the inner strut 155, the lower bracing 160, the precast concrete panel ( 170), etc. are individually manufactured in the factory and transported to the construction site. In addition, since all members except for the upper chord 110 subjected to compressive force are made only of steel, the length of the member fabrication in the factory may be determined by transportation conditions to the bridge construction site. On the other hand, the concrete filling inside the phase current 110 may be performed in a factory, but may also be performed at a construction site.

The assembly of the members brought into the bridge construction site can be performed according to the following sequence.

First, both lower chords 120 and lower bracing 160 are assembled with high tension bolts over the entire section. Then, the stringer 130 and the lower chord 120 are connected to each other using the inner stud 155 to form a triangular inner frame structure. Thereafter, the inclined member 140 is sequentially coupled to the lower chord 120 by fillet welding. Finally, a process of combining the upper chord 110 with the inclined member 140 is performed, and at this time, the upper chord 110 and the stringer 130 are sequentially coupled using the upper strut 150.

When the assembly of the main derrick is completed through the above process, the main derder is mounted on the pier using temporary equipment such as a crane, and then, both ends of the precast concrete panel 170 are connected to the upper chord 110 and the stringer 130 It is installed to be supported by, and the remaining concrete floor plate 175 is constructed by using it as a formwork and a support.

The cast-in-place concrete deck 175 is structurally synthesized with the upper chord 110 by the shear connector 111, etc. in the section where the compressive force acts on the upper chord 110, and the section where the upper chord 110 receives the tensile force. are not synthesized in

The thickness of the precast concrete panel 170 ( _DP in FIG. 2 ) is preferably less than 55% of the total floor plate thickness (D _t , the sum of the thickness of the precast concrete panel and the thickness of the cast-in-place concrete floor plate) do.

[Second Embodiment]

6 is a view showing a cross section of a composite lattice girder bridge 200 according to a second embodiment of the present invention. Among the drawing reference numerals in FIG. 6, the same reference numerals as those in FIGS. 1 to 5D denote the same components that play the same role.

However, in the second embodiment, the lower chords disposed on both sides of the lower portion of the cross section are referred to as the first lower chords 120 and the lower chords disposed between the first lower chords 120 are referred to as the second lower chords 122. do it with The first lower chord 120 has the same structure as the lower chord 120 of the first embodiment.

The upper chord 110 and the first and second lower chords 120 and 122 and the stringers may be made of circular or rectangular steel pipes.

As shown in the drawing, when the width of the target bridge exceeds 13 m, two stringers 130 are arranged at equal intervals on the cross section, and the center of the cross section so that the structural behavior of the stringers 130 and the truss can be secured. A second lower chord 122 is added to the lower part.

Then, the first lower chord 120 and the stringer 130 located on both sides are connected in a hinge structure using a stud (155, a stud installed in a direction perpendicular to the bridge axis) that exists only in the cross section, , The stringer 130 and the second lower chord 122 are connected in the direction of the bridge with the inclined member 240 forming the Waren truss structure, so that the truss behavior directly resists the external load even in the center of the cross section An inverted triangular truss capable of form a structure
Also, the first and second lower chords 120 and 122 may be connected by an X-shaped lower bracing 160 . The lower bracing 160 is connected to the first and second lower chords 120 and 122 by a direction dependent hinge structure. This direction dependent hinge structure has been described in the first embodiment.

The inclined member 240 may be made of a straight steel pipe, square pipe, H-beam, etc., and both ends thereof may be connected to the stringer 130 and the second lower chord 122 in the same way as the inclined member 140. . For example, a joint plate 142 may be installed at both ends of the H-beam, and the joint plate 142 may be coupled between a pair of joint plates 146.

On the other hand, in the section where the upper chord 110 receives the tensile force, the inner reinforcing plate perpendicular to the cross section of the upper chord 110 at the position where the upper chord 110 and the inclined member 140 meet (not shown in the drawing. The upper chord 110 ) and limited to the position where the inclined member meets) inside the upper chord 110, it is possible to prevent damage to the upper chord due to local acupressure and shear stress.

If this method is applied, the composite lattice girder bridge according to the present invention can be used even for bridges with a width exceeding 20 m.

[Third Embodiment]

7a to 7b show cross-sectional shapes of chords and inclined members that can be used in a composite lattice girder according to a third embodiment of the present invention.

In the first and second embodiments, the case where the chords 110, 120, and 122 and the inclined members 140 and 240 are steel pipes of circular cross section has been described as an example, but the chord and inclined member in this embodiment are rectangular cross sections. It may be steel pipes 310 and 312. The rectangular steel tubes 310 and 312 may be manufactured in a factory through a rolling process or by using a steel plate.

[Fourth Embodiment]

8 is a partially cut perspective view showing a composite lattice girder bridge according to a fourth embodiment of the present invention. Among the drawing reference numerals in FIG. 8, the same reference numerals as those in FIGS. 1 to 7 denote the same components that play the same role.

As shown in the figure, the composite lattice girder bridge 400 has first and second upper chords 110 and 410, lower chords 120, and first and second upper chords 110 extending along the bridge axis direction. The inclined member 440 connecting the 410 and the lower chord 120, the upper bracing 450 connecting the first and second upper chords 110 and 410, and the lower chord connecting the lower chord 120 The bracing 160, the precast concrete panel 170 installed to be supported by the first and second phase chords 110 and 410, and the cantilever part precast concrete panels installed on both sides of the precast concrete panel 170 ( 172) and a concrete floor plate 175 formed on the panels 170 and 172.

Compared to the bridges of the first to third embodiments, the composite lattice girder bridge 400 has a second phase chord 410 added, and the inclined member 440 is formed in a straight form and forms a Warren truss. The point and the fact that the inclined member 440 connects the second upper chord 410 and the lower chord 120 and forms a Warren truss, and the cantilever part precast concrete panel on the outside of the precast concrete panel 170 ( 172) is installed to form the cantilever part, and the upper bracing 450 forms an X shape rather than a straight line.

The first phase chord 110 is installed on both upper portions of the cross section, and the second phase chord 410 is installed between the first phase chords 110. The first and second phase chords 110 and 410 have the same structure as the phase chords 110 of the first to third embodiments. The first and second phase chords 110 and 410 may be made of circular or rectangular steel pipes.

Among the first and second phase chords 110 and 410, concrete 119 may be filled in the portion where the compressive force in the throttling direction acts. The filling method is the same as that described in the first embodiment.

On the other hand, the internal reinforcing plate perpendicular to the cross section of the first and second phase chords 110 and 410 at the position where the first and second phase chords 110 and 410 where the tensile force acts meets the inclined member 440 (drawing) Not shown in. By installing the first and second phase chords 110 and 410 and limited to the position where the inclined member meets) inside the first and second phase chords 110 and 410, local acupressure and shear stress Breakage can also be prevented.

The lower chord 120 is installed on both lower portions of the cross section. The lower chord 120 has the same structure as the lower chord 120 of the first to third embodiments. The lower chord 120 may be made of a circular or rectangular steel pipe.

The first upper chord 110 and the lower chord 120 and the second upper chord 410 and the lower chord 120 are connected by an inclined member 440 . The inclined member 440 is made of a straight steel pipe, and both ends thereof are obliquely cut at an angle (θ _S ) of 45° or less with respect to the shaft center line. And, the joint plate 142 is inserted and coupled to both ends. The cutting, the angle θ _S , and the joint plate 142 are the same as those described in the first embodiment.

The inclined member 440 (abdominal member) connects the first upper chord 110 and the lower chord 120 to form a Warren truss structure and connects the second upper chord 410 and the lower chord 120 to form a Warren truss structure form

The joint plate 142 is inserted into and coupled to a pair of joint plates 146 installed in the junction section of the first and second upper chords 110 and 410 and the lower chord 120, the structure of the joint plate 146 and its arrangement angle (θ ₂ ) are the same as the bonding plate structure and arrangement angle (θ ₂ ) of the first to third embodiments. In addition, the coupling of the joint plate 146 and the joint plate 142 may be performed in the same manner as the coupling of the joint plate 146 and the joint plate 142 described in the first to third embodiments. Therefore, the inclined member 440 is coupled to the first and second upper chords 110, 410 and the lower chord 120 by the direction dependent hinge structure, and thus, the axial force of the inclined member 440 and the truss out-of-plane direction Only the moment of is transmitted through the hinge structure, and the moment in the truss in-plane direction is not transmitted.

The first and second phase chords 110 and 410 are connected to each other by an upper bracing 450. Since the upper bracing 450 has the same structure as the lower bracing 160 of the first embodiment, a description thereof will be omitted.

The lower bracing 160 connects the lower chords 120 to each other. The structure of the lower bracing 160 is the same as that of the upper bracing 450 . Further, the connection between the lower bracing 160 and the lower chords 120 on both sides is made by a direction-dependent hinge structure, which has been described in the first embodiment.

The precast concrete panel 170 is installed so that both ends thereof are supported by the first and second phase chords 110 and 410, and the cantilever portion precast concrete panel 172 is outside the precast concrete panel 170. ) is installed. Then, in a state in which the panel 172 is lifted using a crane (not shown), the upper reinforcing bars 171 and 173 of the two panels 170 and 172 are connected to each other with a reinforcing bar coupler (not shown in the drawing) or the like. After connecting and installing a filling material (not shown in the drawing) between the two panels 170 and 172, concrete is poured on the panels 170 and 172 and the filling material to form a concrete floor plate 175. That is, the concrete floor plate 175 is formed by pouring concrete at a construction site using the panels 170 and 172 as formwork and supports. This method is disclosed in Korean Patent Registration No. 10-1206991 of the present inventor, and the contents disclosed in the registration publication of this patent are included in this specification (ie, the contents described in the registration publication form part of this specification, Omitting the description here is to avoid duplication of the same description).

The terms used to describe the embodiments of the present invention in the above are those used to describe the present invention, but are not used to limit the scope of the present invention described in the limitations or claims.

100: composite lattice girder bridge 110: phase chord, first phase chord
111, 112, 113: head-attached stud (front end connector)
118: closing plate 118a: hole for pouring concrete
119: filling concrete
120: lower current, first lower current 122: second lower current
130: stringer 140: inclined member
141: connection plate 142: joint plate
143: flat plate 145: axial center line of the inclined member 140
146: junction plate 147: support plate
150: upper strut 151: connecting plate
152: connecting material 155: inner stud
160: lower bracing 161: connecting plate
162: joint plate 166: joint plate
170: precast concrete panel 171: upper reinforcing bar
172: cantilever part precast concrete panel
173: upper reinforcing bar 175: concrete floor plate
200: composite lattice girder bridge 240: inclined material
310, 312: square pipe 400: composite lattice girder bridge
410: second phase current 440: inclined member
450: upper bracing

Claims (14)

It is a lattice girder bridge with a cross section of three consecutive triangles and a double warrent truss or warrent truss structure on the side,
The upper and lower chords and stringers are composed of circular or rectangular steel pipes, and the inclined members connecting the upper and lower chords are composed of steel pipes or H-beams, and the stringers are extended along the longitudinal direction of the bridge between the top chords on both sides. installed,
The coupling of the inclined member and the upper chord and the coupling of the inclined member and the lower chord are direction dependent hinge structures in which only the axial force of the inclined member and the moment in the truss out-of-plane direction are transmitted, and the moment in the truss in-plane direction is not transmitted,
Neighboring lower chords are connected to each other by a lower bracing, and the lower bracing is a member coupled to each other by a connecting plate 161 in a state where the bent parts are placed in contact with each other after the two steel pipes are bent, respectively, and 'X'' It has a shape,
Since the lower bracing is connected to the lower chord by a direction-dependent hinge structure, the axial force of the steel pipe and the moment in the out-of-plane direction of the plane on which the neighboring lower chord is placed are transmitted between the steel pipe of the lower bracing and the lower chord, but the moment in the in-plane direction of the plane is A lattice girder bridge, characterized in that it is not transmitted. According to claim 1,
After the joint plate is inserted at both ends of the inclined member, they are combined at an arrangement angle (θ ₂ ), but a part of the joint plate protrudes outward from the end of the inclined member,
A pair of spaced joint plates are pre-welded to the upper and lower chords at an angle equal to the arrangement angle (θ ₂ ) so that joint plates can be inserted into the upper and lower chords to which the inclined members are connected,
The direction dependent hinge structure is formed by inserting a joint plate between the joining plates and then welding them together,
The arrangement angle (θ ₂ ) is a lattice girder bridge, characterized in that the angle formed by the inclined member and the upper and lower chords. According to claim 2,
The inclined member is made of steel pipe,
In order to make the double and lentus of the side, after two symmetrically bent inclined members are butted, both side surfaces of the connecting plate 141 are welded to the butted inclined member,
The arrangement angle (θ ₂ ) is 60 ° to 75 °,
The lattice girder bridge, characterized in that the lower shaft center line 145 of the inclined member is on the same straight line as the upper shaft center line 145 of the butted inclined member. delete A lattice girder bridge with a cross section of at least five consecutive triangles and a double warrent truss or warrent truss structure on the side,
At least two stringers are installed to extend along the longitudinal direction of the bridge between both upper chords, the first lower chord is installed on both sides of the lower side of the cross section, and the second lower chord is installed between the first lower chords, ,
The upper chord, the first and second lower chords, and the stringer are composed of circular or rectangular steel pipes, and the inclined member 140 connecting the upper chord and the first lower chord is composed of a steel pipe or H-beam,
In the coupling of the inclined member 140 and the upper chord and the coupling of the inclined member 140 and the first lower chord, only the axial force of the inclined member 140 and the moment in the truss out-of-plane direction are transmitted, and the moment in the truss in-plane direction is not transmitted. It is a dependent hinge structure,
Adjacent first and second lower chords are connected to each other by lower bracing, and the lower bracing is coupled to each other by a connecting plate 161 in a state where the bent parts are placed in contact with each other after the two steel pipes are bent. As a member, it has an 'X' shape,
Since the lower bracing is connected to the first and second lower chords by the direction-dependent hinge structure, between the steel pipe of the lower bracing and the first and second lower chords, the axial force of the steel pipe and the out-of-plane direction of the plane on which the neighboring first and second lower chords are placed A lattice girder bridge, characterized in that the moment is transmitted and the moment in the in-plane direction of the plane is not transmitted. According to claim 5,
The stringer and the second lower chord are connected by an inclined member 240 forming a warren-shaped truss structure in the bridge axis direction, and accordingly, an inverted triangular truss capable of directly resisting external load even in the central part of the cross section. A lattice girder bridge, characterized in that the structure is formed. According to claim 6,
After the joint plates are inserted at both ends of the inclined member 140, they are combined at an angle of arrangement (θ ₂ ), but a part of the joint plate protrudes outward from the end of the inclined member 140,
A pair of joint plates spaced apart so that the joint plate can be inserted into the upper chord and the first lower chord to which the inclined member 140 is connected are pre-welded to the upper chord and the first lower chord at the same angle as the arrangement angle θ ₂ , ,
The direction dependent hinge structure is formed by inserting a joint plate between the joining plates and then welding them together,
The arrangement angle (θ ₂ ) is a lattice girder bridge, characterized in that the angle formed by the inclined member 140 and the upper chord and the angle formed by the inclined member 140 and the first lower chord. According to claim 5,
The inclined member 140 is made of a steel pipe,
In order to make the double and lentus of the side, after the two inclined members 140 that are symmetrically bent are butted, both edges of the connecting plate 141 are welded to the butted inclined member 140,
The arrangement angle (θ ₂ ) is 60 ° to 75 °,
The lattice girder bridge, characterized in that the lower shaft center line 145 of the inclined member 140 is on the same straight line as the upper shaft center line 145 of the butted inclined member 140. delete It is a lattice girder bridge having a structure in which the cross section consists of at least three consecutive triangles,
The first upper chord is installed on both upper sides of the cross section, the second upper chord is installed between the first upper chords, and the lower chord is installed on both sides of the lower side of the cross section,
The connection between the first top chord and the bottom chord and the connection between the second top chord and the bottom chord are made by a straight inclined member 440 to form a Waren truss structure,
The first and second upper chords and lower chords are composed of circular or rectangular steel pipes, and the inclined member 440 is composed of steel pipes or H-beams,
The coupling between the inclined member 440 and the first and second upper chords and the coupling between the inclined member 440 and the lower chord transmit only the axial force of the inclined member 440 and the moment in the out-of-plane direction of the truss, but do not transmit the moment in the in-plane direction of the truss. It is a direction dependent hinge structure that does not
Neighboring lower chords are connected to each other by a lower bracing, and the lower bracing is a member coupled to each other by a connecting plate 161 in a state where the bent parts are placed in contact with each other after the two steel pipes are bent, respectively, and 'X'' It has a shape,
Since the lower bracing is connected to the lower chord by a direction-dependent hinge structure, the axial force of the steel pipe and the moment in the out-of-plane direction of the plane on which the neighboring lower chord is placed are transmitted between the steel pipe of the lower bracing and the lower chord, and the moment in the in-plane direction of the plane is A lattice girder bridge, characterized in that it is not transmitted. According to claim 10,
After the joint plates are inserted at both ends of the inclined member 440, they are combined at an angle of arrangement (θ ₂ ), but a part of the joint plate protrudes outward from the end of the inclined member 440,
A pair of joint plates spaced apart so that joint plates can be inserted into the first and second upper and lower chords to which the inclined member 440 is connected are pre-welded to the upper and lower chords at the same angle as the arrangement angle θ ₂ , ,
The direction-dependent hinge structure is formed by inserting joint plates between joint plates and then welding them together, and the arrangement angle (θ ₂ ) is the angle formed by the inclined member 440 and the first and second upper chords or lower chords. lattice girder bridges. delete delete According to any one of claims 1, 2, 3, 5, 6, 7, 8, 10, 11,
A lattice girder bridge, characterized in that the bridge height is 15 to 25.

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