JP2006063534A - Bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bridge capable of being carried out construction work even in a narrow site. <P>SOLUTION: The bridge comprises foundation work carried out in each of spots required for constructing the bridge, an arch member rigidly connecting both ends thereof to both head ends of the foundation work and placed in such a posture that a circular arc can be upward projected, a plurality of hangers suspended from a circular arc part of the arch member and arranging positions of the lower ends in a predetermined position, a hanging floor slab connected to the lower ends of the hangers and extended in parallel with a line connecting the two spots to each other, a rigidly connecting means rigidly connecting one extended end section of the hanging floor slab to one end section of the arch member opposed thereto and a connecting means connecting the other extended end section of the hanging floor slab by relatively allowing the movement only in the extended direction of the hanging floor slab to the other end section of the arch member to which the extended end section is opposed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bridge for supporting a suspended floor slab by passing it between two points, and in particular, a bridge structure suitable for application when the point where the suspended floor slab is supported is narrow and sufficient foundation work cannot be constructed. Is to try to propose.

In general bridges, excavation work is required to construct the underground part (substructure). In order to reduce the influence on neighboring structures due to the excavation work, it is inevitable that the temporary structure and the countermeasure work at the time of construction are enlarged. In addition, the underground part of the bridge will always be deformed toward the space under the bridge when completed, and if there is a structure that does not allow deformation in this space, it will be necessary to strengthen the underground structure and suppress the deformation. Are usually added.
FIG. 7 shows a general bridge structure. In this example, a case of a bridge having a structure in which a bridge superstructure 3 is placed via a support 2 on a bridge substructure 1 called an abutment or a pier is shown.

  In the case of a bridge with this structure, if the supporting capacity of the ground is insufficient at the lower surface of the bridge substructure 1, foundation work 4 (pile, deep foundation, caisson, etc.) must be constructed under the bridge substructure 1. There is. In this case, the bridge substructure 1 has a deformation M that falls down toward the center of the bridge due to the earth pressure P of the soil 5 on the back surface. When there is a river dike in the space straddling the bridge, the bridge substructure 1 pushes the revetment 6 and affects the dike.

According to the structure of the bridge shown in FIG. 7, it is necessary to perform a large amount of excavation in order to construct the bridge substructure 1. Moreover, construction is difficult in a narrow place, and remaking of the revetment 6 occurs. Further, the scale of the foundation work 4 increases due to the weight of the bridge substructure 1.
There is a bridge ramen called the portal ramen that connects the superstructure and substructure, as shown in FIG. In this portal ramen, the vertical wall portion 7 needs to be constructed by excavation. Further, in the structure shown in FIG. 8, when a load W (vehicle + crowd) is applied, the wall top 8 of the vertical wall 7 is deformed inward M1 and deformed outwardly in the lower part thereof.

For this reason, it is difficult to say that there is no effect on the revetment 6 at the Togawa Bridge, and the amount of excavation is less than when the bridge substructure 1 shown in FIG. 7 is installed. .
Even in the case of a ramen bridge, deformation toward the inner space where the bridge needs to be bridged cannot be avoided, and the span length cannot be increased. Moreover, since excavation is necessary, construction is difficult when the hinterland is narrow.
Fig. 9 shows the structure of a bridge that can be constructed even in places where the hinterland is narrow. The bridge shown in FIG. 9 is called a pile vent type and has a structure in which a pile 9 is placed on the opposite bank, and a bridge superstructure 3 is placed between the head ends of the pile 9 via a support 2.

In the case of this structure, an elastic force that swings in the extending direction is applied to the head end of the pile 9 from the bridge superstructure 3. Since the pile 9 swings due to the expansion and contraction force, there is a drawback that looseness is generated in the bank. For this reason, use is prohibited by the River Structure Ordinance.
The object of the present invention is to propose a bridge structure which can be constructed even in a narrow area and does not affect the embankment.

  According to claim 1 of the present invention, a foundation work placed at each of the points where a bridge is to be constructed, and an arch member arranged in a posture in which both ends are rigidly connected to the head end of the foundation work and an arc projects upward A plurality of suspension members suspended from the arc portion of the arch member and having their lower end positions aligned at a predetermined position, and connected to the lower ends of the plurality of suspension members and parallel to a line connecting the two points. A suspended floor slab, a rigid means for rigidly coupling one extended end of the suspended floor slab to one end of the arch member opposite to the extended end, and the other extended end of the suspended floor slab And a connecting means for allowing movement relative to the other end portion of the arch member facing the extended end portion only in the extending direction of the suspended floor slab. Propose a bridge to be used.

According to a second aspect of the present invention, in the bridge according to the first aspect, at least two arch members are arranged in parallel with an extension line connecting two points, and the above-mentioned suspending material is suspended from the two arch members. We propose a bridge that supports two sides of the suspended floor slab parallel to each other and maintains the suspended floor slab in a position that is extended between the two points.
According to claim 3 of the present invention, in any of the bridges according to claim 1 or 2, the foundation work is constituted by a pile, and the bridge head and the end of the arch member are rigidly connected. Propose.

  According to a fourth aspect of the present invention, in any one of the bridges according to the first to third aspects, the end portions of the arch member are coupled to each other and a tightening means for applying a tightening force between the end portions is provided, and at least one end of the arch member Proposed is a bridge characterized in that it is provided with an adjusting means for adjusting the tightening force of the tightening means.

According to this invention, since it comprises only a bridge superstructure and a foundation work (pile etc.), it is not necessary to carry out excavation backfilling, and construction is possible in a narrow site. Furthermore, it becomes possible to suppress the loosening of the ground as much as possible, and the influence on the bridge periphery during construction can be minimized.
In addition, by adding adjustable tightening means to fasten the arch rise (the height of the arch-like member) and the lower end of the arch, it is possible to guide the deformation of the underground structure in the direction away from the bridge space when completed, and the stress It is possible to actively control the absolute deformation amount.
Furthermore, since the amount of deformation of the underground part can be reduced as compared with the conventional type bridge, it is expected to eliminate the site restriction and avoid the influence on the surrounding existing structures.

  FIG. 1 shows the best mode for carrying out the present invention. In FIG. 1, reference numeral 11 denotes a foundation work composed of piles or the like. By constructing the foundation work 11 with, for example, a pile, the pile can be implemented mainly by driving, so that it can be sufficiently constructed even in a narrow area. The pile is not limited to driving, and a pile constructed with a deep foundation pile, continuous underground wall, caisson, or the like can be used. The example shown in FIG. 2 shows an example in which a plurality of piles are placed in a line. In addition, although the example shown in FIG. 1 shows the example which constructed the foundation work 11 to the revetment 6, the revetment 6 may be a slope or a retaining wall. The same applies to the embodiments of FIGS. 4 and 5 shown below.

  The foundation work 11 is constructed at each of two points where a bridge is to be constructed, and both ends of the arch member 12 are rigidly connected (completely integrated) to the head end 11A. For example, the arch member 12 can be configured by bending a steel pipe into an arch shape, or by bending a long member having an H-shaped steel or a box-shaped cross section into an arch shape. The span rise ratio of the arch is generally set to 1/6 to 1/7, but the present invention is characterized in that the span rise ratio is selected from 1/2 to 1/6 including 1/2. It is. Here, the span rise ratio of the arch refers to (height / span length) of the arch. For example, assuming that the radius of the arch is H, when a semicircular arch is used, the span length is 2H. At this time, the span rise ratio is H / 2H, which is 1/2.

The direction of the force transmitted from the arch member 12 to the head end 11 </ b> A of the foundation work 11 acts in the tangential direction formed by the axis of the end of the arch member 12. Therefore, by making the span rise ratio of the arch member 12 close to ½, the direction of the force transmitted from the arch member 12 acting as the upper work to the foundation work 11 approaches the axial direction of the foundation work 11. That is, it is possible to reduce the outward reaction force Z1 applied to the head end 11A of the foundation work 11.
Since the reaction force Z1 directed outward can be reduced, an effect of reducing the influence on the periphery can be obtained. This is the most excellent operational effect of the present invention.

Two arch members 12 are prepared in parallel with a line connecting two points as shown in FIG. 2, and a suspended floor slab 13 is disposed in a space between the two arch members 12. The suspended floor slab 13 is supported by a suspension member 14 suspended from the arc portion of the arch member 12. The upper end of the suspension member 14 is connected to the arc portion of the arch member 12, and the lower end thereof is aligned with the position of the line connecting the heads of the foundation work 11, for example, and the suspension floor plate 13 is parallel to the lower end of each suspension member 14. Connected to two sides, the suspended floor slab 13 is supported in a posture parallel to the line connecting the heads of the foundation work 11.
In the present invention, furthermore, at one end side in the extending direction of the suspended floor slab 13, the rigid connection means 15 (see FIG. 3) is rigidly connected to the rigid connection point between the foundation work 11 and the arch member 12, but at the other end side of the extended end, Connection is relatively permitted only in the extending direction of the suspended floor slab 13 with respect to the rigid connection point of the foundation work 11 and the arch member 12 and is connected by a connecting means 16 that does not move in a direction orthogonal to the direction.

With this structure, the suspended floor slab 13 does not act as a connecting member for connecting two points, and even if the head of the foundation work 11 is displaced in the axial direction connecting the two points at one point, the displacement Is not transmitted directly to the other foundation work 11. As a result, it is possible to reduce the transmission of a horizontal force such as an earthquake to the opposite bank, and the influence on the revetment 6 can be reduced.
On the other hand, claim 4 of the present invention further proposes a configuration in which a strand coupling means and an adjusting means for adjusting the coupling amount of the strand coupling means are provided between the ends of the arch member 12.
FIG. 4 shows an embodiment thereof. In FIG. 4, the suspended floor slab 13 is omitted. In FIG. 4, 17 is a tightening means, and 18 is an adjusting means. The tightening means 17 can be constituted by, for example, a wire or a steel rod. A wire, a steel rod, or the like is installed between the end portions of the arch member 12, and a tightening force in a direction for tightening the arc of the arch member 12 is applied between the end portions of the arch member 12. Therefore, by the tightening force of the tightening means 17, an inward force Z2 can be generated between the head ends 11A of the foundation work 11. As a result, the outward force Z1 applied from the arch member 12 can be canceled out. For example, the adjusting means 18 may be constituted by a tension adjusting mechanism that combines a bolt that penetrates the arch member 12 in a direction perpendicular to the axis thereof and that is connected to the tightening means 17 on one end side and a nut that is screwed to the bolt. it can. By adjusting the coupling amount (tightening force) of the tightening means 17 with the adjusting means 18, the inward force applied to the head end 11 </ b> A of the foundation work 11 can be adjusted. That is, by adjusting the tightening force of the tightening means 17, the displacement of the arch member 12 and the foundation work 11 and the sectional force such as the bending moment, shearing force, compressive force, and tension generated at an arbitrary point can be adjusted.

  As a result, since the inward force applied to the foundation work 11 can be arbitrarily adjusted even after completion, the outward force Z1 applied to the head end 11A of the foundation work 11 from the arch member 12 is always properly offset. It can be adjusted to a state and can be maintained in an appropriate state for a long time.

Example 1 is shown in FIG. In this embodiment, a case is shown in which the foundation work 11 is constructed in a plurality of rows (two rows in the figure) for each opposite bank. Even when a plurality of rows are constructed in this way, the head ends of the foundation works 11 are rigidly connected to each other, and the end of the arch member 12 is provided at the rigidly connected portion.
As described above, when the foundation work 11 has a structure in which a plurality of rows are constructed, the drag of the foundation work 11 is enhanced, and an advantage that the influence on the periphery can be further reduced can be obtained.

  Example 2 is shown in FIG. In this embodiment, a case in which the tightening means 17 and the side of the suspended floor slab 13 are further connected by a strand 19 is shown. By adopting this structure, the roll of the suspended floor slab 13 can be suppressed. In particular, by changing the length of the strand 19 for each connecting position, it is possible to suppress the occurrence of resonance and further enhance the rolling suppression effect.

  Since the bridge according to the present invention can be constructed even at a point where the conditions of the opposite shore are bad, it is used for a bridge constructed in a narrow urban area, a mountainous area, along a river, or in a wetland.

The side view for demonstrating the best form for implementing this invention. The top view of FIG. The top view for demonstrating the connection structure of the suspended floor slab used with the best form shown in FIG. The side view for demonstrating the tightening means proposed in Claim 4 of this invention. The side view for demonstrating the Example of the foundation work which can be applied to this invention. The top view for demonstrating the deformation | transformation Example of the tightening means proposed by this invention. The side view for demonstrating a prior art. Similarly, the side view for demonstrating a prior art. Similarly, the side view for demonstrating a prior art.

Explanation of symbols

6 Revetment Z1 Outward force 11 Foundation work Z2 Inward force 11A Head of foundation work 15 Rigid means 12 Arch member 16 Connection means 13 Suspended floor plate 17 Tightening means 14 Suspended material 18 Adjusting means

Claims (4)

Foundation works constructed at each point where a bridge should be installed,
Both ends are rigidly connected to the head end of this foundation work, and an arch member arranged in a posture in which an arc protrudes upwards;
A plurality of suspension members that are suspended from the arc portion of the arch member, and whose lower end positions are aligned at a predetermined position;
The suspended floor slab connected to the lower ends of the plurality of suspension members and extended in parallel with the line connecting the two points,
Rigid connection means for rigidly connecting one extended end of the suspended floor slab to one end of the arch member facing the extended end;
A connecting means for connecting the other extended end of the suspended floor slab to the other end of the arch member facing the extended end relatively only in the extending direction of the suspended floor slab,
A bridge characterized by comprising.   2. The bridge according to claim 1, wherein at least two arch members are arranged in parallel with an extension line connecting the two points, and the suspended floor slabs are mutually attached by a suspension member suspended from the two arch members. A bridge characterized by supporting two parallel sides and maintaining a posture in which a suspended floor slab is passed between the two points.   3. The bridge according to claim 1, wherein the foundation work is composed of a pile, and the pile head and an end of the arch member are rigidly connected. The bridge according to any one of claims 1 to 3, wherein the ends of the arch member are coupled to each other, and a tightening means for applying a tightening force between the ends is provided at at least one end of the arch member. Adjusting means for adjusting the tightening force of the tightening means;
A bridge characterized by comprising.

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