JP2016199956A - Bridge construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a bridge by installing a pile foundation while reducing noise and vibration.SOLUTION: In a construction method of a bridge 1, a cross beam 4 is disposed above a steel pipe pile 2A that has been already set, and a main girder 5 on which floor slabs are arranged is connected to the cross beam 4. A movable construction truss girder 7 is moved to the front of the main girder 5 so as to protrude. The cross beam 4 is installed at a tip of the protruded movable construction truss girder 7. The main girder 5a on which new floor slabs 3a are fixed is connected to a connection member of the cross beam 4 to make a cantilever beam structure 8. A pile driver 10 is disposed on a tip of the new floor slab 3a and a rotary pile 2 that is temporarily fixed to a sheath pile of the cross beam 4 is installed by rotating and pressing in the pile underground. Although a rotational reaction applied to the pile driver 10 that rotates and installs the rotary pile 2 becomes a force to twist and deform the new floor slab 3a and the main girder 5a, the force can be suppressed by the movable construction truss girder 7 protruding on both sides. These processes are repeated to construct the bridge 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bridge construction method using pile vents (pile piers) composed of a plurality of rotating piles in a bridge structure such as a road or a railway.

  Conventionally, when constructing bridges such as roads and railways on sloped areas such as mountainous areas and coasts, foundation piles have been placed in sloped areas and valleys using heavy machinery such as pile driving machines, and bridges have been constructed. For example, in the road widening method described in Patent Document 1, a foundation pile is driven on an inclined surface or a valley side with a pile driver or the like on a valley side of an existing road in a mountainous area, and a pile head block, a girder girder, By constructing the main body of the pier for one span in the order of the girder, the lining receiving plate, and the lining plate, the existing road was widened and the construction proceeded sequentially forward.

Also, the pile-type pier construction method described in Patent Document 2 also projects the main girder from the completed part of the pier in a cantilevered manner, adjusts the main girder overhang with the wire, and forms a tubular shape through the pile head fixing pipe of the horizontal girder. The pile was fixed by staking it down down the hole. Also in the temporary pier construction method described in Patent Document 3, a flat pier panel is set by a crawler crane or the like, and a steel pipe pile is driven by a crawler crane or the like as a pile pier.
These methods were used for road construction in mountainous areas and piers on the coast, etc., and the bridges were constructed by a handrail method.

Japanese Patent No. 3978644 Japanese Patent No. 3043320 Japanese Patent No. 3211673

  By the way, each construction method described in Patent Documents 1 to 3 described above is a method for constructing a pile foundation of a pile vent by placing a steel pipe pile into the ground by a down-the-hole hammer or a vibro construction method in a mountainous area or a coast. Even if noise and vibration were generated, there was no problem. However, it has been difficult to drive piles by using the down-the-hole hammer or the vibro method described above in urban areas where noise regulation and vibration regulation are imposed.

  The present invention has been made in view of such circumstances, and provides a method for constructing a bridge that constructs a bridge by placing a pile foundation as a support column while reducing noise and vibration. Objective.

The method for constructing a bridge according to the present invention includes a step of projecting a mobile erection girder in front of an already installed column, main girder, and floor slab, and a new main girder and floor slab are projected along the movable erection girder. A cantilever structure and a step of placing a pile driver on a new floor slab and placing a rotating pile on the front side of the main girder that is overhanged and integrating it as a support column. The bridge is constructed by repeating the process.
According to the present invention, a movable erection girder is projected in front of a main girder and a floor slab provided on an existing column, and a new main girder and a floor slab are projected and connected along the movable erection girder to be cantilevered. It is assumed that the pile striking machine is placed with a new floor slab as the work floor and the rotary pile is placed in the ground and integrated with the overhanging main girder. By repeating this work, noise and vibration are repeated. It can be reduced to build a bridge.

In addition, the rotating reaction force acting on the pile driving machine for rotating and setting the rotary pile is suppressed by the overhanging movable construction girder.
When the rotating pile is rotated and placed, the floor slab and the torsional deformation force acting on the main girder that are projected by the rotational reaction force acting on the pile driver are applied to the cantilever structure on both sides of the cantilever structure. It can be received and suppressed.

Moreover, you may make it receive the pushing-in force and pulling-out force which act on the support | pillar previously installed by the movable installation girder with the blade | wing provided in the support | pillar previously installed.
The pushing force and the pulling force act on a plurality of columns already installed by the movable erection girder, and can be received by the blades provided on the rotating piles forming these columns.

Moreover, it is preferable that a horizontal girder is installed in front of the overhanging movable erection girder in the cantilever structure, and the rotating girder temporarily fixes the rotary pile in a sheath arranged in advance.
A rotary pile is inserted and temporarily fixed to the sheath of the horizontal girder in advance, and the ramen structure is established by placing the horizontal girder in front of the movable erection girder and driving the rotary pile with a pile driver. Can be placed in the ground with high accuracy.

In the present invention, the process of constructing the cantilever structure is
(1) Work by attaching a horizontal girder to a mobile erection girder and a process of projecting and connecting a new main girder and floor slab to the horizontal girder, or (2) projecting a new main girder and floor slab It may be constructed by a step of installing and a step of attaching a horizontal girder to a movable erection girder and a new main girder.
After temporarily fixing the horizontal girder to the movable erection girder, a cantilever structure can be constructed by projecting a new main girder and floor slab and connecting them to the horizontal girder.
Or after extending and installing a new main girder and a floor slab, you may construct | assemble a cantilever structure by attaching a horizontal girder to a movable installation girder and a new main girder.

  According to the method for constructing a bridge according to the present invention, it is possible to reduce noise, vibration, and the like by driving a rotary pile with a pile driving machine provided on a new overhanging slab. Moreover, the torsional deformation generated in the new floor slab and main girder due to the rotational reaction force of the rotating pile can be received and suppressed by the mobile erection girder, and the bridge can be handed over.

It is a figure which shows the construction process of the bridge by the cantilever structure by embodiment of this invention. It is a perspective view which shows the state which drives a rotary pile with a pile driving machine on the floor slab of the cantilever structure shown in FIG. It is sectional drawing which shows a cross beam. It is a top view of the cross beam shown in FIG. FIG. 2 shows a method for constructing a bridge by a cantilever method, in which (a) is a side view showing a process of projecting a movable truss girder in front of an existing floor slab, and (b) is a plan view. It is a figure which shows the process which connected the cross beam to the front side of a movable installation truss girder, (a) is a side view, (b) is a top view. It is a figure which shows the process of constructing the superstructure of a main girder and a floor slab in a horizontal girder, (a) is a side view, (b) is a top view. It is a figure which shows the process which drives a rotary pile through the sheath of a cross beam, (a) is a side view, (b) is a top view. It is a figure which shows the new process of moving the movable construction truss girder forward and supporting it in a cantilevered manner after one step of the method for constructing the bridge, (a) is a side view, and (b) is a plan view. .

Hereinafter, a bridge construction method according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a process for placing a rotating pile 2 in a method for constructing a pile vent (pile pier) type bridge 1 according to an embodiment of the present invention. The structure in the middle of the construction of the bridge shown in FIG. 1 is that a floor slab 3 such as a PC floor slab is installed on top of a steel pipe pile 2A (post) composed of rotating piles 2 placed on a hard ground in the ground at a predetermined interval. Has been. The floor slab 3 is fixed to the upper part of a plurality of main girders 5 which are longitudinal girders extending in the longitudinal direction between a pair of transverse girders 4 arranged at intervals. The main girder 5 and the floor slab 3 are manufactured and integrated in advance in a factory or the like as a superstructure. In FIG. 1, the superstructure in which the main girder 5 and the floor slab 3 are integrated is transported by, for example, a truck and is prepared to be suspended by a crawler crane 9.
A main girder 5 arranged at a predetermined interval projects in front of the steel pipe pile 2A on the front end side, and a floor slab 3 is disposed and supported on the upper side of the main girder 5A. It is connected to the steel pipe pile 2A so as to be removable by screws or the like. In addition, let the movable installation truss girder 7, the horizontal girder 4, the main girder 5, and the floor slab 3 of the cantilever support part extended to the front of the steel pipe pile 2A of the front end side be the cantilever structure 8.

In this specification, the floor slab 3 and the main girder 5 supported by the steel pipe pile 2A are used as the existing floor slab 3 and the main girder 5, and the floor slab is projected on the tip side and supported by the cantilever beam structure 8. 3 and the main girder 5 are referred to as a new floor slab 3a and a main girder 5a (simply referred to as a floor slab 3a or a main girder 5a). A crawler crane 9 is installed on the existing floor slab 3, and a small pile driving machine 10 for installing the rotary pile 2 is installed on the new floor slab 3a in front of the floor slab 3. .
Further, a transverse girder 4 is connected to a main girder 5a and a movable erected truss girder 7 at the front end of a new floor slab 3a in the cantilever structure 8 shown in FIG. As shown in FIG. 2, a pair of truss girders 12 are arranged along the longitudinal direction on both sides of the floor slab 3a, and these truss girders 12 are supported by supporters 13 and tie rods 14 as shown in FIG. Are connected to each other. The truss girder 12 is provided with a main girder mounting scaffold 12 a located below the main girder 5.

  Further, as shown in FIGS. 3 and 4, in the cross beam 4, sheath pipes 15 are arranged at predetermined intervals inside the cross beam 4. It is inserted and temporarily fixed. In the cross beam 4, a connecting member 16 for connecting to the main beam 5 a is provided before and after the direction orthogonal to the cross beam 4. And the plate-shaped blade | wing 17 which makes a spiral shape is expanded and fixed to the outer side from the outer peripheral surface at the lower end part of the rotary pile 2. As shown in FIG.

Next, the construction method of the bridge 1 provided with the construction structure of the bridge 1 mentioned above is demonstrated centering on FIGS.
First, in FIG.1 and FIG.5, the cross beam 4 is supported by the steel pipe pile 2A of the front end already installed in the bridge 1 in the middle of construction, and the main girder 5 which installed the floor slab 3 is connected to the cross beam 4. FIG. . A crawler crane 9 is installed at the tip of the floor slab 3 on the main girder 5 supported by the steel pipe pile 2A. And the movable erection truss girder 7 is lifted by the crawler crane 9 and moved forward, and its rear part is connected to the steel pipe pile 2A (post), main girder 5 or cross girder 4 that has already been constructed. Alternatively, instead of lifting and moving the movable erected truss girder 7, it may be moved forward by sliding movement. As a result, the distal end side of the mobile erected truss girder 7 protrudes in front of the existing floor slab 3 and is cantilevered.

  Next, as shown in FIG. 6, the cross beam 4 is lifted by the crawler crane 9 and installed at the tip of the mobile erection truss girder 7, and both ends of the cross beam 4 are arranged on both sides of the mobile erection truss girder 7. 12 is temporarily fixed. The cross beam 4 is preliminarily fixed in the factory in advance by fixing the sheath tube 15 at a predetermined interval in the longitudinal direction of the cross beam 4 and inserting the rotary pile 2 into the sheath tube 15. . The rotary pile 2 has, for example, a substantially circular tube shape. Therefore, the sheath tube 15 is also formed in a circular tube shape.

Then, as shown in FIG. 7, between the horizontal beam 4 newly installed at the tip of the mobile installation truss beam 7 supported in an overhang state and the existing horizontal beam 4 on the rear side, the steel or concrete product is used. A superstructure which is a plurality of main girders 5a to which a floor slab 3a such as a floor slab is fixed is installed, and both ends thereof are fixed to the connecting members 16 of the cross girders 4 with bolts and nuts.
In this state, as shown in FIG. 8, the small pile driving machine 10 is moved to the tip side of the floor slab 3 a on the main girder 5 a that is supported in an overhanging manner, and this floor slab 3 a is connected to the working floor of the pile driving machine 10. To do. Then, the rotary pile 2 temporarily fixed in the sheath pipe 15 of the lateral girder 4 on the distal end side of the mobile trusses 7 supported in a cantilever manner is pushed into the ground while being rotated by a small pile driver 10. Rotate and press to place. Since the blades 17 are formed, for example, in a spiral shape at the tip of the rotary pile 2, the rotary pile 2 is penetrated into the ground while being rotated by the propulsive force of the blades 17. In the example shown in FIG. 4, the rotary pile 2 and the sheath pipe 15 are installed in two rows on the cross beam 4, but the number and the rows of the rotary pile 2 and the sheath tube 15 are arbitrary. You may arrange in.

The pile driving machine 10 generates a large rotational reaction force by rotationally press-fitting the rotary pile 2 during construction (see FIG. 2), and this rotational reaction force is connected to the floor slab 3a via the caterpillar of the small pile driving machine 10. It is transmitted to the beam 5a as a torsional deformation force. The rotational reaction force applied to the floor slab 3a and the main girder 5a is received by the pair of truss girder 12 of the movable erected truss girder 7 or by the truss girder 12, the support 13 and the tie rod 14, and the floor slab 3a and the main girder are received. The torsional deformation of 5a is suppressed.
In general, the rotary pile 2 used for the bridge 1 has a relatively large pile diameter and requires a large rotational force for rotational press-fitting, so that it cannot be rotated by a flying method using a crane such as the crawler crane 9. Therefore, it is necessary to install the pile driving machine 10 near the placement position of the rotary pile 2. In this embodiment, the movable construction truss girder 7, the transverse girder 4, and the main girder 5 a of the upper work supported in a cantilever manner are combined to reduce the weight of the pile driver 10 and the reaction force of the rotational torque of the rotary pile 2. I can resist.

  In this way, the ramen structure is established by driving the rotary pile 2 on the hard ground in the ground through the sheath 15 of the cross beam 4 connected to the main beam 5a. Further, the clearance between the sheath tube 15 and the driven rotary pile 2 is set to the minimum necessary, and the clearance is filled with mortar to form a joint portion of the ramen structure. And the construction accuracy of the rotary pile 2 can be improved by inserting and temporarily fixing the rotary pile 2 to the sheath pipe 15 of the cross beam 4 beforehand.

In addition, the cantilever structure 8 in which the transverse girder 4, the main girder 5a, the floor slab 3a, etc. are installed in a cantilevered movable truss girder 7 is cantilevered in the steps shown in FIGS. . In this state, the indentation stress FA due to the cantilever support of the cantilever structure 8 acts on the steel pipe pile 2A on the tip side that has been placed first, and the pullout stress FB acts on the steel pipe pile 2A on the rear side. Further, when the rotary pile 2 is driven at the tip of the cantilever structure 8, a particularly large pulling force FB acts on the steel pipe pile 2A.
Even in these cases, since the blade 17 expanded in diameter at the tip is fixed to the lower end portion of the rotary pile 2 that is each steel pipe pile 2A, it resists both the indentation stress FA and the pull-out stress FB of the steel pipe pile 2A. it can. Therefore, the blades 17 of the rotary pile 2 are reasonable for use as reaction forces of the indentation stress FA and the pull-out stress FB.

  Next, after the pile driving is completed, the pile driving machine 10 is moved backward, the crawler crane 9 is moved to the tip side of the new floor slab 3a, and the movable erected truss girder 7 is lifted forward as shown in FIG. By moving and supporting the cantilever again, the construction process of the bridge 1 described above is repeated.

As described above, according to the construction method of the bridge 1 according to the present embodiment, in a state where the cantilever structure 8 supports the cantilever, the rotary pile 2 is installed on the floor slab 3a in the vicinity of the cross beam 4 on the tip side. Since rotary press-fitting is performed by the pile driving machine 10, noise and vibration can be reduced as compared with a case where a pile is driven by a down-the-hole hammer or a vibro hammer. Therefore, it can be constructed even in urban areas and towns where noise and vibration are restricted.
Moreover, a large rotational reaction force is generated when the rotary pile 2 is pressed into the ground, and the torsional deformation force is transmitted to the floor slab 3a and the main girder 5a of the cantilever structure 8 through the pile driving machine 10. However, the movable erected truss girder 7 can resist and suppress torsional deformation.

Further, in the state of cantilever support by the cantilever structure 8, the pushing force FA is applied to the steel pipe pile 2A that has been placed behind the rotating pile 2, and the pulling force FB is applied to the steel pipe pile 2A that is adjacent to the pushing pile 2A. However, the blade 17 provided at the tip of each steel pipe pile 2A can resist and absorb both the pushing force FA and the pulling force FB.
Moreover, in this embodiment, the pile driving machine 10 in which the sheath pipe 15 is attached to the cross beam 4 in advance and the rotary pile 2 is inserted and temporarily fixed in each sheath pipe 15 at the construction site of the bridge 1 in the factory or the like. Therefore, the construction accuracy of the rotary pile 2 is high.

  Note that the present invention is not limited to the above-described embodiment, and the configuration of the above-described embodiment can be appropriately changed or replaced without departing from the gist of the present invention. These construction methods are also included in the scope of the present invention. In the following, modifications of the present invention will be described using the same reference numerals for the same or similar members and parts of the above-described embodiment.

For example, in the construction method of the bridge 1 according to the above-described embodiment, the mobile erected truss girder 7 is projected and supported forward, and the horizontal girder 4 is attached to the tip of the mobile erected truss girder 7 to form a new main girder 5a and floor slab. Although the rotary pile 2 is driven through the sheath tube 15 after the 3a is installed, the present invention is not limited to such a process sequence.
For example, after the mobile erected truss girder 7 is attached in a cantilever shape, a main girder 5a with a new floor slab 3a is attached, and the horizontal girder 4 is fixed to the mobile erected truss girder 7 and the main girder 5a. Then, the rotary pile 2 may be driven. Alternatively, after attaching the mobile erected truss girder 7 in a cantilever shape, the main girder 5a having the floor slab 3a is attached, and then the horizontal girder 4 is attached to the main girder 5a and the truss girder 12 to You may set up.

In the embodiment described above, the main girder mounting scaffolds 12a are respectively installed on the truss girders 12 on both sides of the movable erection truss girder 7, and the main girder 5a is arranged and fixed to the horizontal girder 4 with bolts or the like. However, the main girder mounting scaffold 12a may not be provided.
In the above-described embodiment, the blade 17 is provided at the lower end of the rotary pile 2 to resist the pushing force FA and the pull-out force FB, but the blade 17 may not necessarily be provided in the rotary pile 2. In this case, what is necessary is just to lengthen the length of the rotary pile 2 and to make the casting depth of the rotary pile 2 into the ground deeper, or to set the pile diameter of the rotary pile 2 larger.

  Further, in the above-described embodiment, the mobile erected truss girder 7 contributes to receiving a reaction force of torsion generated when the rotary pile 2 is driven, but it is not necessarily required to be the mobile erected truss girder 7. Instead of this, a girder, a box girder, etc. may be adopted. However, the mobile erected truss girder 7 is the lightest, and is most preferable for the construction method of the bridge 1 by repeating the overhanging movement of the cantilever structure 8. In the present invention, the movable girder truss girder 7, the girder girder, the box girder and the like can be moved to the overhanging position as cantilever beams, and the main girder 5a and the floor are subjected to the rotational reaction force when the rotary pile 2 is rotated. A member that suppresses torsional deformation of the plate 3a is referred to as a movable erection girder.

Moreover, in this invention, the steel pipe pile 2A which rotationally press-fitted the rotary pile 2 comprises the support | pillar of the bridge 1. FIG.
In addition, since the construction method of the bridge 1 according to the present invention is low noise and low vibration because the rotary pile 2 is rotationally press-fitted into the ground by the pile driving machine 10, it is suitable for the construction method of the bridge 1 in towns and urban areas. However, it goes without saying that the present invention can also be adopted in a method for constructing the bridge 1 in a mountainous area, a coast, or the like, as shown in the conventional technique described above.

DESCRIPTION OF SYMBOLS 1 Bridge 2 Rotating pile 2A Steel pipe pile 3 Floor slab 3a New floor slab 5 Main girder 5a New main girder 4 Horizontal girder 7 Mobile installation truss girder 8 Cantilever structure 9 Crawler crane 10 Pile driver 12 Truss girder 15 Saya tube

Claims (5)

Projecting a mobile erection girder in front of the pillar, main girder and floor slab that have already been installed;
Extending and arranging a new main girder and floor slab along the movable erection girder to form a cantilever structure;
Arranging a pile driving machine on the new floor slab and placing a rotary pile on the front side of the overhanging main girder and integrating it as a strut, and
A bridge construction method characterized in that a bridge is constructed by repeating the steps described above.   The method for constructing a bridge according to claim 1, wherein a reaction force of rotation acting on a pile driving machine that rotates and places the rotary pile is suppressed by the projecting movable erected girder.   The method for constructing a bridge according to claim 1 or 2, wherein a pushing force and a pulling force acting on the support column previously installed by the movable installation girder are received by a blade provided on the support column installed in advance. .   The horizontal girder is installed in the front side of the protruding movable installation girder in the cantilever structure, and the horizontal girder temporarily fixes the rotary pile in a sheath arranged in advance. The construction method of the bridge described in the section. The step of constructing the cantilever structure includes
(1) The construction is carried out by the step of attaching the cross girder to the movable erection girder and the step of projecting and connecting a new main girder and floor slab to the cross girder, or (2) the new main girder and 5. The method of constructing a bridge according to claim 4, wherein construction is performed by a step of projecting and installing a floor slab, and a step of attaching the horizontal girder to the movable erection girder and the new main girder.

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