JP3678719B2 - End separation type upper suspension type suspension floor slab bridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upstream suspension floor slab bridge that can be applied to a road bridge among suspension floor slab bridges, and more particularly to an end separation type upstream suspension floor slab bridge.
[0002]
[Prior art]
In general, when a suspended floor slab bridge is applied to a road bridge, for example, an upper suspension floor slab bridge 20 as shown in FIG. No. 323841 or JP-A-11-229320) is used.
[0003]
The conventional structural form is such that the primary cable 1 and at least the secondary cable 21 on the suspended floor slab 5 side are tension-fixed to the abutment 2 and the end of the suspended floor slab 5 is integrated with the abutment 2. This is an upper-floor type suspension floor slab bridge 20 having an integrated bridge body end portion structure.
[0004]
[Problems to be solved by the invention]
However, the conventional upper suspension type slab bridge 20 has the following problems (1) to (4).
(1) Since deformation of the suspended floor slab 5 due to creep / drying shrinkage, temperature change, and the like is constrained by the bending rigidity of the upper floor slab 4, the tensile force generated in the suspended floor slab 5 becomes larger than that of the straight path type.
(2) An excessive bending moment is generated in the vertical member 12 at the end due to the difference in deformation between the suspended floor slab 5 and the upper floor slab 4 due to creep, drying shrinkage, temperature change, and the like.
(3) Since the load (vertical load acting on the bridge body) is supported by the axial rigidity of the suspended floor slab 5, the tensile force generated on the suspended floor slab 5 and the horizontal force acting on the abutment 2 are excessive.
(4) Since both the primary cable 1 and the secondary cable 21 are fixed on the abutment 2, the fixing brackets 22 and 23 are arranged densely.
[0005]
In order to improve these problems, the present invention provides an end-separated type upper road type suspended floor slab bridge in which the end of the suspended floor slab is separated from the abutment 2 and the suspended floor slab and the upper floor slab 4 are integrated. For the purpose.
[0006]
[Means for Solving the Problems]
In order to advantageously solve the above-described problem, in the end-separated upper-path type suspended floor slab bridge according to claim 1 of the present invention, the end of the primary cable 1 as an erection cable is fixed to the abutment 2 and is bridged. The upper floor slab 4 and the suspended floor slab 5 constituting the bridge body 3 are integrated at the end of the bridge body in the direction of the axis of the bridge, and the upper floor slab 4 or The cable 6 arranged on the suspended floor slab 5 is fixed to the bridge end 7 separated from the abutment 1 without being fixed to the abutment, and the primary cable is fixed to the bridge end block. It is provided so that it may penetrate 8 .
[0007]
According to a second aspect of the present invention, in the end-separated upper road type suspended floor slab bridge according to the first aspect, the concrete is cast on the bridge body end portion 7 in the bridge axis direction so that the end portion of the upper floor slab 4 is provided. And a bridge body end block 8 for integrating the ends of the suspended floor slab 5 are provided, the bridge body end block 8 is supported by the abutment 2 via a support 9, and the primary cable is connected to the bridge body. It is provided so as to penetrate the end block 8 .
[0008]
According to the present invention, the following actions and effects are obtained.
(1) In the structure of the present invention, since the end portion of the suspended floor slab is separated from the abutment, the tensile force generated in the suspended floor slab by creep / drying shrinkage and temperature change can be made smaller than that of the conventional structure.
(2) In the conventional structure, the upper floor slab is supported by the suspended floor slab via a vertical member, and the suspended floor slab is fixed to the abutment. However, in the structure of the present invention, the suspended floor slab and the upper floor slab are integrated at the end, and the bridge body end is separated from the abutment. Therefore, the difference in deformation between the suspended floor slab and the upper floor slab is small, and an excessive bending moment does not act on the vertical member.
(3) In the conventional structure, the post-load (live load, bridge surface load, etc.) is supported by a suspended floor slab via a vertical member, and a horizontal force acts on the abutment due to the load. Since the upper floor slab and the suspended floor slab are integrated at the end of the body (girder) and separated from the abutment, the upper floor slab and the suspended floor slab act as a girder against the live load, and the horizontal force acting on the abutment is small. It can be suppressed.
(4) In the conventional structure, both the primary cable for erection and the secondary cable for introducing prestress to the suspended floor slab are fixed on the abutment. In the structure of the invention, since the primary cable is fixed to the abutment and the secondary cable is fixed to the end of the beam, the cable arrangement of the fixing portion is easy.
(5) When the bridge is no longer needed, the bridge can be removed by using the primary cable used as the erection cable and performing the reverse process of erection.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
1, FIG. 2, FIG. 5 and FIG. 6 show a first embodiment of an end-separated upper-path type suspension floor slab bridge 10 according to the present invention, in which primary cables 1 and secondary on the suspension floor slab 5 side are shown. The cable 17 is an external cable. In the present invention, a cable using a PC steel material such as a PC steel wire or a PC steel stranded wire and continuous fibers can be used.
[0011]
More specifically, a plurality of primary cables 1 installed across the abutment 2 facing each other at an interval are arranged in parallel, and the ends of the primary cables 1 are fixed to the abutment 2. It is fixed by the metal fitting 11.
[0012]
The primary cable 1 is used as an erection cable. Each abutment 2 is fixed to the ground 15 by a plurality of ground anchors 14, and each abutment 2 is provided with a plurality of casing tubes made of steel or the like for passing through the end of the primary cable 1 at right angles to the bridge axis. Embedded and fixed at intervals in the direction.
[0013]
In order to form the bridge body end 7 at the bridge axial direction end portion of the bridge body 3 so that the support apparatus 9 is installed on the abutment 2 and supported by the support apparatus 9, the support device 9 of each abutment 2 is formed. After arranging reinforcement and formwork on the concrete, concrete 19 is placed, and a concrete bridge body end block 8 which is a bridge body end 7 separated from each abutment 2 is built. .
The bridge body end portion 7 is an end portion (having both ends) of the bridge body 3 in the bridge axis direction, and the bridge body end block 8 is separated from the abutment 2 and is attached to the abutment 2 with a support device 9. It is a block-like member located at the end portion in the bridge axis direction of the bridge body 3 (that is, the bridge body end portion 7) supported via the like.
In addition, in the upper part and the intermediate part of the bridge body end block 8, there are through holes for inserting a secondary cable so as to be opposed to the suspended floor slab 5 and the upper floor slab 4 at intervals in the direction perpendicular to the bridge axis, respectively. A sheath or the like is embedded and formed, and an opening for attaching a fixing fitting is formed at the outer end of the bridge body end block 8 in the bridge axis direction.
[0014]
At the intermediate portion of each primary cable 1, a number of precast concrete blocks 5b are arranged in series in the bridge axis direction, as shown in FIG. 5, via saddles 5a provided on each block 5b. As shown in FIG. 2, the primary cable 1 is slid and installed at a predetermined position of the primary cable 1 by a suspension construction method or the like, and is locked to the primary cable 1 as necessary. When placing on the primary cable 1, illustration is omitted, but the crane is placed on the primary cable 1 by a crane on the abutment 2 or the abutment end block 8 as appropriate, and each abutment 2 or the abutment end block 8. It is towed by a tow rope from the side.
[0015]
Each saddle 5a is provided with a groove having an arc-shaped cross section extending in the direction of the bridge axis, and in order to reduce friction between the primary cable 1 and the secondary cable, the teflon ( (Registered trademark) plate (ethylene tetrafluoride plate) and the like are provided.
[0016]
Thus, after installing a lot of blocks 5b for the suspended floor slabs between the bridge body end blocks 8, the vertical members 12 made of steel or concrete straddle the adjacent blocks 5b on the central side in the bridge axis direction. In addition, the blocks 5b are fixed to the adjacent blocks 5b by bolts or the like (not shown) at both ends in the bridge axis direction of the respective blocks 5b and standing upright on both sides in the direction perpendicular to the bridge axis.
[0017]
Further, in order to construct the block 4b for the upper floor slab 4, the block 4b is arranged over the adjacent vertical members 12 with an interval in the bridge axis direction. The block 4b is constructed by being fixed by, for example.
[0018]
A joint mortar (illustrated) between the blocks 5b for the suspended floor slabs and the blocks 4b for the upper floor slabs, and between the bridge body end block 8 and the blocks 5b for the suspended floor slabs and the blocks 4b for the upper floor slabs. The suspended floor slab 5 and the upper floor slab 4 are connected to the end block 8 of the bridge body.
[0019]
Moreover, while passing through one bridge body end block 8, a plurality of secondary cables 6 (6 a) are passed through the suspended floor slab 5 in the bridge axis direction at intervals in the direction perpendicular to the bridge axis, and the other The bridge body end block 8 is inserted and arranged. Similarly, a plurality of secondary cables 6 (6b) are passed through the upper floor slab 4 from one bridge body end block 8 and to the other bridge body end block 8 at intervals in a direction perpendicular to the bridge axis. Insert it in the axial direction.
[0020]
Then, each secondary cable 6 (6a, 6b) is tensioned, and both ends of each secondary cable 6 (6a, 6b) are fixed to each bridge body end block 8 by fixing brackets 17, 18. The fixing of both ends of the secondary cable (6a, 6b) is not fixed to the abutment 2 but fixed to the bridge body end block 8, and is an important point in the present invention.
[0021]
In this way, the upper floor slab 4 and the suspended floor slab 5 constituting the bridge body 3 are integrated by the bridge body end block 8 at the bridge body end in the bridge axis direction, and the bridge girder 16 including the vertical member 12 is configured. In addition, as described above, the secondary cable 6 inserted into the upper floor slab 4 or the suspended floor slab 5 separately from the primary cable 1 is separated from the abutment 2 in the state of the bridge body end. The tension is fixed to the part block 8.
[0022]
The tension adjustment of the primary cable 1 is appropriately performed at a necessary stage, and the secondary tension of the ground anchor 14 is also appropriately performed at a necessary stage.
[0023]
In addition, after constructing the bridge girder 16, a bridge surface such as road pavement is constructed on the upper surface of the upper floor slab 4 at an appropriate time, and the end separation type upper road type suspended floor slab bridge 10 is constructed.
[0024]
3, 4 and 6 show a second embodiment of the present invention. In this embodiment, the secondary cable 6 (6a) on the suspended floor slab 5 side is an internal cable system. Since other configurations are the same as those of the above-described embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.
[0025]
In each of the above-described embodiments, when dismantling and removing the end separation type upper suspension type suspension floor bridge 10, the end separation type upper suspension type suspension floor can be easily obtained by, for example, a reverse procedure from the construction procedure described above or below. The plate bridge 10 can be dismantled and removed, so that on the abutment 2 side, in order to open each primary cable and secondary cable as appropriate, notched recesses 24 and 25 filled with concrete after tensioning these cables are provided. However, it is provided.
[0026]
According to the above embodiment, the precast upper floor block 4b or the suspended floor block 5b and the vertical member 12 can be used, for example, in mountains only by constructing only the bridge body end block 8 on site. As a bridge between single diameters in a zone or the like, the end separation type upper suspension type suspension floor bridge 10 can be easily constructed and constructed in a short construction period.
[0027]
Next, when the construction procedure in the case of constructing the edge separation type upper suspension type slab bridge 10 of the present invention is briefly described, for example, construction is performed by the following construction procedure.
<Example of construction procedure 1>
When the primary cable 1 for the suspended floor slab and the secondary cable 6 (6a, 6b) are both external cables.
(1) On the abutment 2, the support device 9 is installed, and an end portion place hitting portion (bridge body end block 8) is constructed.
(2) A primary cable for the suspended floor slab 5 is installed and fixed between the abutments 2, and the secondary cable 6 is installed and fixed between the bridge body end blocks 8.
(3) The suspended floor slab 5 is installed. Using the primary cable 1, each block 5 b is installed while sliding on the primary cable 1.
(4) The vertical member 12 is installed on the suspended floor slab 5.
(5) A block 4b for the upper floor slab 4 is installed on the vertical member 12.
(6) A joint mortar is placed between the blocks 4b for the upper floor slab, between the blocks 5b for the suspended floor slab, or between the bridge end block 8 and each block 4b (5b).
(7) Insert the secondary cable 6 (6b) into the upper floor slab 4.
(8) The secondary cable 6 (6a) on the suspended floor slab 5 side and the secondary cable 6 (6b) on the upper floor slab 4 side are tensioned and fixed to each bridge body end block 8.
(9) Install the bridge surface.
In addition, you may reverse the construction order of said (6) and (7). Also, the tension of the primary cable is appropriately adjusted at a necessary stage. Furthermore, secondary tension of the ground anchor is performed at the necessary stage.
[0028]
<Example 2 of construction procedure>
When the primary cable for the suspended floor slab (lower floor slab) is an external cable and the secondary cable is an internal cable.
(1) On the abutment 2, the support device 9 is installed, and an end portion place hitting portion (bridge body end block 8) is constructed.
(2) The primary cable 1 for the suspended floor slab 5 is installed between the abutments 2 and fixed.
(3) The suspended floor slab 5 is installed. Using the primary cable 1, the block 5 b for the suspended floor slab 5 is installed while sliding on the primary cable 1.
(4) The vertical member 12 is installed on the suspended floor slab 5.
(5) The upper floor slab 4 is installed on the vertical member 12.
(6) A joint mortar is placed between the blocks 4b for the upper floor slab 4 or between the blocks 5b for the suspended floor slab 5 or between the bridge end block 8 and each block 4b (5b).
(7) The secondary cables 6 (6a, b) are inserted into the suspended floor slab 5 and the upper floor slab 4, respectively.
(8) The secondary cable 6 (6a) on the suspended floor slab 5 side and the secondary cable 6 (6b) on the upper floor slab 4 side are tensioned and fixed to each bridge body end block 8.
(9) Install the bridge surface.
Note that tension adjustment of the primary cable 1 is appropriately performed at a necessary stage. Further, the secondary tension of the ground anchor 14 is performed at a necessary stage.
[0029]
The primary and secondary cables on the suspended floor slab side may be either an internal cable system or an external cable system, and a combination of the internal cable system and the external cable system should be adopted. May be.
[0030]
In the case of the end separation type upper suspension type suspension floor bridge 10 according to the present invention, a temporary end separation type upper passage type suspension floor slab bridge that is permanently installed or disassembled and removed later may be used depending on use conditions or the like.
[0031]
In the case of the present invention, since the primary cable as the erection cable 1 has a structure that supports only the weight of the bridge body, an increase in the horizontal force acting on the abutment 2 due to the bridge surface load, live load, and temperature change. The amount is kept small compared to the conventional structure.
[0032]
When implementing this invention, as shown in FIG. 7, it is good also as the edge part isolation | separation type upper path type suspended floor slab bridge 10 arrange | positioned in the state which inclined the vertical | vertical material 12 only to the bridge-axis direction.
[0033]
In the case of each said embodiment, the vertical material 12 is provided so that it may straddle the adjacent floor slabs 4 and 5, and it is set as the structure which transmits shearing force.
[0034]
【The invention's effect】
The present invention has the following effects.
(1) In the structure of the present invention, since the end portion of the suspended floor slab is separated from the abutment, the tensile force generated in the suspended floor slab by creep / drying shrinkage and temperature change can be made smaller than that of the conventional structure.
(2) In the conventional structure, the upper floor slab is supported by the suspended floor slab via a vertical member, and the suspended floor slab is fixed to the abutment. However, in the structure of the present invention, the suspended floor slab and the upper floor slab are integrated at the end, and the bridge body end is separated from the abutment. Therefore, the difference in deformation between the suspended floor slab and the upper floor slab is small, and an excessive bending moment does not act on the vertical member.
(3) In the conventional structure, the post-load (live load, bridge surface load, etc.) is supported by a suspended floor slab via a vertical member, and a horizontal force acts on the abutment due to the load. Since the upper floor slab and the suspended floor slab are integrated at the end of the body (girder) and separated from the abutment, the upper floor slab and the suspended floor slab act as a girder against the live load, and the horizontal force acting on the abutment is small. It can be suppressed.
(4) In the conventional structure, since the primary cable for erection and the secondary cable for live load are fixed on the abutment, it is difficult to arrange the cable in the fixing portion. In the structure of the present invention, Since the primary cable is fixed to the abutment and the secondary cable is fixed to the end portion of the beam, the cable arrangement of the fixing portion is easy.
(5) When the bridge is no longer necessary, the primary cable used as the erection cable is used, and for example, the bridge can be removed by performing the reverse process of erection.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing the vicinity of one end of an end-separated upper-path type suspended floor slab bridge according to a first embodiment of the present invention.
FIG. 2 is a longitudinal side view showing the vicinity of one end portion of the end-separated upper-path type suspended floor slab bridge according to the first embodiment of the present invention, where the cutting position is changed.
FIG. 3 is a longitudinal side view showing the vicinity of one end of an end-separated upper-path type suspended floor slab bridge according to a second embodiment of the present invention.
FIG. 4 is a longitudinal sectional side view showing the vicinity of one end portion of a second embodiment of the present invention where the cutting position is changed in the end separation type upper suspension type suspension deck bridge.
FIG. 5 is a longitudinal front view of the end-separated upper-path type suspended floor slab bridge according to the first embodiment of the present invention.
FIG. 6 is a schematic side view showing the entire end-separated upper-path suspension floor slab bridge according to the first or second embodiment of the present invention.
FIG. 7 is a schematic side view showing an end-separated upper-path type suspended floor slab bridge in a form in which vertical members are arranged in an inclined state.
FIG. 8 is a vertical side view showing an end structure of a conventional upper-floor type suspension floor slab bridge.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Primary cable 2 Abutment 3 Bridge body 4 Upper floor slab 4b Block for upper floor slab 5 Lower floor slab 5a Saddle 5b Block for lower floor slab 6 PC steel or outer cable 7 Bridge body end 8 Bridge body end block 9 Bearing Device 10 End separation type upper suspension type slab bridge 11 Fixing bracket 12 Vertical material 14 Ground anchor 15 Ground 16 Bridge girder 17 Fixing bracket 18 Fixing bracket 19 Concrete 20 Conventional upper path type suspension floor slab bridge 21 Secondary cable 22 Fixing bracket 23 Fixing bracket 24 Notch recess 25 Notch recess

Claims (2)

In the upper-floor type suspension floor bridge, the end of the primary cable as the erection cable is fixed to the abutment so as to support only the weight of the bridge body. The cable that is integrated at the body end and arranged on the upper floor slab or the suspended floor slab separately from the primary cable is in a state of being tensioned to the end of the bridge body that is separated from the abutment without being fixed to the abutment And the primary cable is provided so as to penetrate the end portion of the bridge body . Concrete is cast at the end of the bridge body in the direction of the bridge axis to form a bridge body end block for integrating the end of the upper floor slab and the end of the suspended floor slab. 2. The end-separated upper-path type suspended floor slab bridge according to claim 1, wherein the primary cable is supported by the abutment via the bridge and is provided so as to penetrate the end block of the bridge body .

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