JP2012255300A - Construction method for upper road type suspended slab bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount an upper road girder in a stable state while reducing the horizontal inclination of a precast concrete slab supported by cables, during constructing an upper road type suspended slab bridge where a column is erected on the concrete slab supported along the deflected cables and the upper road girder is supported thereon.SOLUTION: A precast concrete slab 21 is supported between end blocks 3 and 4 along cables 12a, and two water reserving containers 30 and 31 are placed in the cross direction of the precast concrete slab. In a step of erecting columns 8 on the precast concrete slab to form an upper road girder 9, when a deviational load works on the precast concrete slab to cause inclination or rotating displacement in the horizontal direction, the amount of water in the containers is adjusted to avoid the inclination or the like. The adjustment of the amount of water is performed by moving the water between the containers arrayed in the cross direction, filling water into one container or discharging water from one container. The containers can be suspended from and supported on the lower side of the precast concrete slab.

Description

  In the present invention, an upright suspension floor slab bridge, which is a type of bridge, that is, a pillar is erected on a thin concrete plate member (suspended floor slab) supported by a stretched cable, and a road surface is formed thereon. The present invention relates to a method for constructing an upper-floor type suspension floor slab bridge that supports upper girder for the purpose.

The upper-floor suspended floor slab bridge is a thin concrete plate-like member with a high tension cable stretched between the piers, between the abutments or between the piers and the abutments, and with a deflection (sag) along the cable. Support the suspended floor slab). And a support | pillar is set up on the suspended floor slab which is a plate-shaped member, and an upper road girder is built on this.
In a suspended floor slab bridge where the upper surface of the suspended floor slab is the road surface, a slope is generated on the road surface due to the sag of the suspended floor slab. be able to. Moreover, it can also be set as what is called a self-supporting type suspension floor slab bridge which connects the both ends of a suspension floor slab with an upper road girder, transmits the tensile force which acts on a suspension floor slab to an upper road girder, and acts as a compression force on an upper road girder. As a result, the horizontal reaction force acting on the abutment or pier is reduced, and the stability of the abutment and the like in the completed system can be improved.

As a method for constructing such an upper suspension type slab bridge, there is one disclosed in Patent Document 1, for example.
In this construction method, a structural unit composed of a precast concrete board that becomes a suspended floor slab and two struts standing obliquely thereon is supported by a cable stretched between two abutments. And it moves along this cable and arranges sequentially from the position adjacent to the abutment. Subsequently, a precast concrete segment serving as an upper girder is supported on the struts of the structural unit, and is sequentially arranged in the axial direction of the bridge from a position adjacent to one abutment. Thereafter, concrete is placed between the precast concrete plates arranged along the cable and between the segments of the precast concrete arranged above, and the precast concrete plates and the segments are suspended floor plates that are continuous in the axial direction of the bridge, and This is the upper girder. In addition, the precast concrete board used as a suspended floor slab may be made into the continuous suspended floor slab by placing concrete between each board before constructing an upper girder.

JP 2001-182016 A

However, the following problems may occur in the construction of the above-described upper suspension type slab bridge.
The upper-floor type suspended floor slab bridge is constructed by supporting the precast concrete board on the cable stretched in a state where deflection occurs, and constructing the upper road girder on this, so the support of the members during construction becomes unstable. easy. In particular, in the state where the pillars are erected on the precast concrete plate, and in the state where the load for constructing the upper girder is applied to these pillars, the center of gravity of the structural member under construction becomes high, and the structure becomes unstable. Become.
On the other hand, during the construction of the upper-floor suspended floor slab bridge, the rigidity is small before the upper girder is completed, and even when a slight load is applied, the precast concrete plate or the axial direction of the cable supported by the cable A suspended floor slab that is continuous to the axis is inclined in a direction perpendicular to the axis. In addition, the precast concrete plate is likely to be inclined due to construction errors or the like, and the member under construction supported by the cable tends to be unstable.

  The present invention has been made in view of the circumstances as described above, and its purpose is to provide a construction method for an upper suspension floor slab bridge with improved stability against falling in the direction perpendicular to the cable axis, that is, in the lateral direction. Is to provide.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a suspension floor slab which is a thin concrete plate-like member formed along a cable stretched between two opposing abutments or piers. A method for constructing an upper-floor type suspension floor slab bridge having a column erected on a suspension floor slab and an upper girder supported on the column, the step of stretching a cable between an abutment or a pier, and the suspension floor Arranging a plurality of precast concrete plates constituting a plate along the cable and supporting the plates; and on the support columns erected from all the precast concrete plates or a plurality of selected precast concrete plates. A step of constructing an upper girder, and a step of forming concrete between the precast concrete plates to form the continuous suspended floor slab, All or part of the step of constructing the upper girder includes supporting all the precast concrete plates or a plurality of selected precast concrete plates with a container storing water, and precast concrete plates supported by the cables and Provided is a method for constructing an upper-floor type suspended floor slab bridge characterized by adjusting the position of the center of gravity of a member supported by the precast concrete board.

In the construction method of the above-mentioned upper-floor suspended floor bridge, the cable stretched between the abutment or the pier is either between the abutment and the abutment, between the abutment and the pier, or between the abutment and the pier. It may be. These cables may be fixed at both ends of the abutment or pier even when the upper-floor suspension floor slab bridge is completed, or after the suspension floor slab and the upper road girder are formed, The fixing position may be changed to the end portion of the upper girder on the abutment or the pier.
In addition, the support column erected from the precast concrete plate may be erected after the precast concrete plate is supported by the cable and arranged at a predetermined position, or is attached in advance to the precast concrete plate, The precast concrete plate may be supported by a cable together with the support and arranged at a predetermined position.
On the other hand, the step of placing concrete between precast concrete plates to form a suspended floor slab in which a plurality of precast concrete plates are continuous may be performed before the step of building the upper girder, or the step of building the upper girder You may go at the same time. Alternatively, it may be performed when a part of the process of constructing the upper girder is completed or when the construction of the upper girder is completed.

  In the construction method of this upper suspension type slab bridge, the position of the center of gravity of the member supported by the cable is lowered by the water stored in the container, and the stability in the lateral direction is improved. Further, by adjusting the amount of water in the container, the position of the center of gravity can be adjusted according to the progress of the construction. Therefore, the operation | work which builds an upper road girder in the support | pillar standingly arranged by the precast concrete board becomes easy.

  The invention according to claim 2 is the construction method of the upper-floor type suspended floor slab bridge according to claim 1, wherein a plurality of the containers are arranged in a width direction with respect to an axis of the cable of the precast concrete plate, and the precast concrete plate The water amount difference between the containers arranged in the width direction is adjusted so as to reduce the inclination in the direction perpendicular to the axis of the cable.

  In this method of constructing an upper-floor type suspension floor slab bridge, by providing a difference in the amount of water in the containers arranged in the width direction of the precast concrete plate, the edge of the precast concrete plate on the side where the container with a large amount of water is placed descends. Displace to Thereby, the displacement difference of the width direction produced by the uneven load etc. can be reduced. Therefore, it is possible to correct the inclination of the precast concrete plate in the width direction and to construct the upper-floor type suspension floor slab bridge in a stable state.

  The invention according to claim 3 is the construction method of the upper-floor type suspension floor slab bridge according to claim 2, in which the water amount difference is adjusted, and the precast concrete board or the upper road girder is substantially horizontal in the width direction. A step of placing concrete between the precast concrete plates to form a continuous suspended floor slab or a step of making the upper girder continuous between both ends of the suspended floor slab is performed.

  In the construction method of this upper suspension type slab bridge, by adjusting the amount of water, the precast concrete plates or the upper passage girders are connected in a state of being substantially horizontal in the width direction, and the rigidity is increased. As a result, the suspended floor slab or upper girder connected with the precast concrete plate is formed in an accurate shape. For the load loaded thereafter, the displacement that increases in rigidity and tilts in the width direction is suppressed to a small value.

  The invention according to claim 4 is the construction method of the upper-floor type suspension floor slab bridge according to claim 2 or claim 3, wherein the adjustment of the water amount difference detects a displacement difference or an inclination in the width direction of the precast concrete board. It is assumed that a sensor is installed and a pump controlled based on the detection result of the sensor is used.

  In this method of constructing an upper-floor type suspension floor slab bridge, when the precast concrete plate is tilted in the width direction due to a newly applied load, the water volume is adjusted so that the sensor detects this and corrects it quickly. Is possible. This makes it possible to efficiently perform the operation of adjusting the amount of water and to avoid the unstable state from continuing for a long time.

  According to a fifth aspect of the present invention, in the method for constructing the upper-floor type suspended floor slab bridge according to any one of the first to fourth aspects, the container is suspended and supported below the precast concrete board.

  In this construction method of the upper-floor type suspended floor slab bridge, the center of gravity of the precast concrete board and the members supported by the precast concrete board can be lowered by supporting the container in which water is stored below the precast concrete board. Thereby, it becomes easy to support a precast concrete board in the stable state and to avoid the horizontal inclination and fall of a suspended floor slab.

  The invention according to claim 6 is the construction method of the upper suspension type slab bridge according to claim 5, wherein the precast concrete plate is provided with a hole penetrating in the vertical direction, and the container is deformed flexibly. A material formed from a material is used to pass through the hole from above the precast concrete plate and support it under the precast concrete plate, and then pour water into the container.

  In this method for constructing an upper-floor suspended floor slab bridge, even after the precast concrete board is supported along the cable, the container can be supported below the precast concrete board to store water by the work on the precast concrete board. Easy to do.

The invention according to claim 7 is the construction method of the upper-floor suspended floor slab bridge according to claim 1, wherein the container is in contact with the vicinity of both end edges in the width direction of the precast concrete board.
It is assumed that the two suspended members are suspended and supported at substantially the center in the width direction of the suspended floor slab.

  In this method of constructing an upper suspension type slab bridge, the center of gravity of the precast concrete plate and the member supported by the precast concrete plate can be lowered, and when the precast concrete plate is inclined, the weight of water stored in the container is reduced in the width direction. Acts to correct the inclination of For example, when one side of the precast concrete board is tilted downward, the tensile force of the suspension material joined near the edge of the downwardly displaced side decreases, and the vicinity of the other edge of the precast concrete board The tensile force of the hanger bonded to the slab increases. As a result, a restoring force that attempts to restore the inclination of the precast concrete plate acts, reduces the displacement difference in the width direction of the precast concrete plate without providing multiple containers in the width direction, and maintains a state close to horizontal It becomes possible to do.

  The invention according to claim 8 is the construction method of the upper-floor type suspended floor slab bridge according to any one of claims 1 to 7, wherein the column is erected in advance on the precast concrete plate, and the precast concrete plate is The container is supported by the cable, and the container in which water is stored is supported by the precast concrete board, and the precast concrete board is moved along the cable and arranged at a predetermined position.

In this method for constructing an upper-floor type suspended floor slab bridge, the precast concrete plates on which the columns are erected are arranged along the cable, so the construction period can be shortened.
In addition, the precast concrete plate provided with support columns becomes unstable and unstable due to the support provided with the support columns, but the center of gravity is supported by supporting the container storing water. It can be lowered and moved along the cable in a stable state and arranged.

  As explained above, in the construction method of the upper suspension type slab bridge according to the present invention, when the member is suspended and supported by the cable, the position of the center of gravity is lowered and the construction can be stably performed. Further, by adjusting the amount of water in the plurality of containers arranged in the width direction at the time of construction, it is possible to construct the construction while suppressing the inclination in the width direction of the precast concrete plate supported by suspension.

It is a schematic side view which shows an example of the upper path type suspension floor slab bridge constructed | assembled by the method which concerns on this invention. It is sectional drawing of the upper-path-type suspension floor slab bridge shown in FIG. It is a side view which expands and shows the edge part of the upper-path-type suspension floor slab bridge shown in FIG. It is the schematic which shows the process of constructing the upper-path type suspension floor slab bridge shown in FIG. It is the schematic which shows the process of constructing the upper-path type suspension floor slab bridge shown in FIG. It is the schematic which shows the process of constructing the upper-path type suspension floor slab bridge shown in FIG. It is the schematic which shows the process of constructing the upper-path type suspension floor slab bridge shown in FIG. It is sectional drawing which shows the fixing state of the cable in erection. It is a schematic sectional drawing which shows the state which suspended and supported the precast concrete board with the 1st cable. It is a schematic sectional drawing which shows the state which mounted the container on the precast concrete board. It is the schematic explaining adjustment of the amount of water in a container when a precast concrete board inclines in the width direction. It is a schematic sectional drawing which shows the other example of the form which makes a precast concrete board support a container. It is a schematic sectional drawing which shows the other example of the form which makes a precast concrete board support a container. It is a schematic sectional drawing which shows the other example of the form which makes a precast concrete board support a container. It is a schematic sectional drawing which shows the other example of the form which makes a precast concrete board support a container. It is a schematic sectional drawing which shows the process of making a precast concrete board support a container with another form. It is a schematic sectional drawing which shows the process of making a precast concrete board support a container with another form. It is a schematic sectional drawing which shows the application example of the technique which uses the container which accommodated water for construction of a suspended floor slab bridge. It is a schematic sectional drawing which shows the other application example of the technique which uses the container which accommodated water for construction of a suspended floor slab bridge.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side view of an upper type suspended floor slab bridge that can be constructed by the method according to the present invention. FIG. 2 is a cross-sectional view of this upper suspension type slab bridge.
This upper suspension type slab bridge is constructed between two abutments 1 and 2, and concrete end blocks 3 and 4 supported on the abutments 1 and 2 through fences 5 and 6, respectively. A suspended floor slab 7 stretched between the end blocks 3 and 4, a plurality of columns 8 erected on the suspended floor slab 7, and the end blocks 3 and 4 are formed so as to be continuous, The main part is composed of the upper girder 9 supported on the suspended floor slab 7 by the support column 8.

  The abutments 1 and 2 are constructed of reinforced concrete on the solid ground 20 at the position where the bridge is constructed, and are firmly fixed to the ground 20 or the rock by the earth anchors 10 and 11 when constructed. After the suspended floor slab 7 and the upper girder 9 are completed, the earth anchors 10 and 11 are unnecessary and can be removed, but may be left as they are.

  As the ridges 5 and 6, rubber ridges, cast ridges or the like can be used. These eaves 5 and 6 support the girders so that they can rotate around a horizontal axis perpendicular to the axis of the bridge. And among the eaves 5 and 6 that support both ends of the girder, one restrains horizontal movement in the axial direction of the bridge, and the other permits movement. Horizontal movement in the direction perpendicular to the axis of the bridge is constraining both ridges 5 and 6.

  The end blocks 3 and 4 may be made of cast-in-place concrete, or precast concrete that has been manufactured in advance at a factory or the like. The upper girder 9 continuous between both end blocks 3 and 4 is joined to the upper part of the vertical surfaces of these end blocks 3 and 4, and the suspended floor slab 7 is joined to the lower part. And both ends of the cable 12 (not shown in FIG. 1) for supporting the suspended floor slab 7 are fixed to these end blocks 3 and 4, respectively.

  The suspended floor slab 7 is formed so that a thin concrete plate-like member is continuous between the two end blocks 3 and 4, and is supported by the tensile force of the cable 12 in a state in which deflection occurs. . The suspended floor slab 7 is connected to a plurality of precast concrete plates 21 created in a production yard near the factory or the site, and between these and the precast concrete plates 21 and the end blocks 3 and 4. It is made of cast-in-place concrete.

The cable 12 includes a plurality of first cables 12a and a plurality of second cables 12b, and the first cable 12a is a precast concrete plate forming a suspended floor slab 7 as shown in FIG. Is supported in a groove 21a formed on the upper side of 21 and supports the precast concrete plate 21 via a steel rod 22 which is bridged on the upper side of the first cable 12a and fixed to the precast concrete plate 21. It has become. And concrete is cast in this groove | channel 21a, and the 1st cable 21a is embedded. As shown in FIG. 3, these first cables 12a can be fixed to the end blocks 3 and 4 of the concrete by screwing nuts 17a to the ends.
The second cable 12 b is inserted into a sheath 18 embedded in the concrete of the suspended floor slab 7, and both ends are also fixed to the end blocks 3 and 4.

The support column 8 is made of steel, and as shown in FIG. 1, is raised obliquely upward from the upper surface of the suspended floor slab 7 and is configured to support the upper road girder 9. And the support | pillars 8a and 8b which incline in the direction which becomes a mutually opposite side of a bridge axis direction are started from the adjacent position on the suspended floor slab 7, and these support | pillars 8 form a warren truss with the suspended floor slab 7 and the upper road girder 9. ing. As shown in FIG. 2, these struts 8 are raised from the vicinity of both side edges of the suspended floor slab 7, and their upper ends are connected to each other by a horizontal connecting member 19.
In addition, the support | pillar 8 can also use what consists of fiber reinforcement mortar or a synthetic resin.
Further, in this embodiment, the column 8 is formed to rise obliquely upward from the suspended floor slab 7, but may be formed substantially vertically from the suspended floor slab 7. That is, the column, the suspended floor slab, and the upper road girder may not have a truss structure.

The upper girder 9 is composed of a segment made of precast concrete supported on the top of the support column 8 and cast-in-place concrete that continues between these segments. And reinforcement with the reinforcing bar is made so that it can fully endure the bending moment and the shearing force due to its own weight or live load.
The upper girder 9 can also be formed by assembling a support work on the suspended floor slab 7 and placing concrete on site.

Next, it is one Embodiment of the invention which concerns on this application, Comprising: The method to construct | assemble the said upper-path type suspended floor slab bridge is demonstrated.
First, as shown in FIG. 4, abutments 1 and 2 are constructed on both sides of a position where the upper suspension type slab bridge is constructed. The abutments 1 and 2 are firmly fixed to the ground 20 or the rock by the earth anchors 10 and 11 so that they can resist a large horizontal force. Then, the end blocks 3 and 4 are supported on the abutments 1 and 2 via the flanges 5 and 6, and are temporarily fixed to the abutments 1 and 2.

Thereafter, the first cable 12 a is stretched between the two end blocks 3 and 4. The cable to be stretched here is only the first cable 12a. As shown in FIG. 8, the cable is inserted into the sheath embedded in the end block 3, and the extension cable 14 is connected to the abutments 1 and 2. To settle. The extension cable 14 can be connected by a coupler 13 to a fixing body 15 that is crimped to both ends of the first cable 12a. As a result, the reaction force acting from the first cable 12a during installation is borne on the abutment 1 so that the reaction force does not act on the end block 3. A nut 17a is screwed onto the fixing body 15, and a reaction force is applied to the end blocks 3 and 4 in the completed system to fix the cable 12a.
In addition, the rear part of the abutment 1 is reinforced by the PC steel material 16 in the vertical direction so that excessive tensile stress is not generated in the rear cross section of the abutment 1 when the reaction force from the extension cable 14 is applied.

Next, the precast concrete board 21 forming the suspended floor slab is suspended and supported by the first cable 12a. As shown in FIG. 9, the first cable 12a is supported by lifting the precast concrete plate 21 so that the cable 12a fits in the groove 21a provided on the upper side of the precast concrete plate 21, and short steel on the upper side of the cable 12a. This is done by locking the bar 22 to the precast concrete plate 21. The precast concrete board 21 moves along the cable while being locked to the cable 12a as described above, and is arranged in order from the position adjacent to the one end block 4.
Reinforcing bars (not shown) for joining these precast concrete plates to each other are projected from both end faces of the precast concrete plate 21 in the axial direction of the suspended floor slab.

When the precast concrete board 21 is arranged in almost the entire region between the end blocks 3 and 4, the containers 30 and 31 are placed on the precast concrete board 21 in an empty state to store water as shown in FIG. To do. As shown in FIG. 10, these containers 30, 31 are arranged in two in the width direction on each precast concrete plate 21, and are respectively placed on both sides of the center line of the suspended floor slab bridge. Then, a predetermined amount of water is poured into these containers. The containers 30 and 31 may be placed on all precast concrete plates, or may be placed on a plurality of selected precast concrete plates. The containers 30 and 31 can be made of various materials such as a synthetic resin, a drum can, and a waterproof bag-like member that is supported by a frame. Is desirable. Further, it is preferable that the upper part is widely opened and water can be easily injected and discharged by a pump or the like.
FIG. 5 is a cross-sectional view of the containers 30 and 31 to show the water stored in the containers 30 and 31.

The amount of water injected into the container arranged in the width direction of the precast concrete plate 21 is such that the precast concrete plate 21 is arranged along the first cable 12a, that is, before the support column 8 and the upper road girder 9 are formed. Is preferably the same amount for the two containers 30,31. However, when the precast concrete board 21 inclines in the width direction due to an error in the position at which the container is arranged, a difference is provided in the amount of water stored between the two containers to correct the inclination. Further, the containers 30 and 31 arranged at a plurality of positions in the axial direction of the first cable 12a have substantially the same amount of water stored in the two containers, or in the axial direction of the first cable 12a. It is good to set so that a big difference may not arise in the storage amount of water in an adjacent position.
In addition, the total amount of water stored in the two containers 30 and 31 placed in the width direction of the precast concrete plate 21 is arranged in the subsequent steps of starting up the column 8 and forming the upper beam 9. It is desirable that the load be greater than or equal to the load acting near the position. That is, it is preferable to distribute and inject the water equivalent to the load of the column 8 standing on the precast concrete plate 21 and the upper girder 9 installed above the precast concrete plate 21 into the containers 30 and 31.

The containers 30 and 31 are arranged as described above, and the columns 8 are erected on the plurality of precast concrete plates 21 in a state where water is stored in the containers 30 and 31.
As shown in FIG. 2, the support column 8 is raised from the precast concrete plate 21. And as shown in FIG. 6, it makes it incline in the axial direction of an upper-path type suspension floor slab bridge, a lower end adjoins another support | pillar, and adjoins the support | pillar different from the support | pillar which adjoins the lower end part in an upper end part. The upper ends of these columns 8 are connected in the axial direction of the bridge by a connecting member 25. These struts 8 are preferably joined to each other so that force is transmitted to other adjacent struts at the upper end or the lower end. On the other hand, the lower end of the column 8 and the precast concrete plate 21 are joined by connecting the column 8 to an anchor (not shown) protruding from the surface of the precast concrete plate 21 and between the lower end of the column 8 and the precast concrete plate 21. Fill with concrete or mortar. By this hardening of the concrete or mortar, the precast concrete plate 21 and the support column 8 are integrated, and the force is transmitted between them.

Subsequently, as shown in FIG. 7, a precast concrete segment 23 to be the upper road girder 9 is arranged so as to be bridged between the tops of the columns 8. The segment 23 is arranged in such a manner that the connecting member 25 connecting the tops of the columns 8 is used as a rail, or a rail is laid on the connecting member 25 and travels on the rail 23 as shown in FIG. Are sequentially arranged from a position adjacent to the end block 4.
In FIG. 7, the containers 30 and 31 are shown in cross section to show the water stored in the containers 30 and 31.

  In the step of erecting the column 8 and the step of forming the upper beam 9, members forming the column 8 and the upper beam 9 may be unevenly loaded in the width direction of the precast concrete plate 21. In this way, when the load is unevenly loaded, a displacement difference in the vertical direction is generated at both edges in the width direction of the precast concrete plate 21 in the vicinity of the position where the load acts, and the load is inclined in the width direction. In such a case, the difference in the amount of water in the two containers 30 and 31 placed on the precast concrete board 21 is adjusted to correct the inclination of the precast concrete board 21 in the width direction.

For example, as shown in FIG. 11 (a), when a large deflection occurs at one end 21R in the width direction of the precast concrete plate 21 and the precast concrete plate 21 is inclined, the precast concrete plate 21 is bent downward. A part of the water in the container 31 placed on the large end side is discharged, and the discharged water is poured into the container 30 on the opposite side, that is, with a small deflection. Accordingly, as shown in FIG. 11B, the deflection on the side where the container 30 with the increased amount of water is placed increases, and the deflection on the side where the container 31 with the reduced amount of water is placed decreases. Therefore, the displacement difference in the width direction of the precast concrete board 21 is eliminated by moving the water between the two containers 30 and 31 to adjust the water amount difference, and approaches the horizontal.
The difference in the amount of water between the two containers 30 and 31 is preferably adjusted by the movement of water between the two containers 30 and 31 as described above, but is not limited to this, and the upper side is inclined with little deflection. It may be adjusted by pouring water into the container 30 located in the container, or may be adjusted by discharging water in the container 31 on the lower side inclined with a large deflection.

Further, the adjustment of the water amount difference can be performed by operating a pump or the like (not shown) while an operator looks at the inclination state of the precast concrete plate 21, but the displacement difference between both side edges of the precast concrete plate 21 or It is also possible to install a sensor 32 for detecting the inclination on the precast concrete plate 21 and control a pump or the like by a control device such as a computer based on the detection result.
In addition, the said sensor 32 can use the well-known thing which can detect the displacement difference or inclination of the width direction of the precast concrete board 21, For example, an electronic level meter etc. can be used.

  On the other hand, in the step of sequentially arranging the segments 23 to form the upper girder 9, the load of the segments 23 acts on the precast concrete plate 21 positioned below, and the precasts adjacent to each other in the axial direction of the first cable 12a. A large relative displacement in the vertical direction may occur between the concrete plates 21. In other words, when a load acts on a limited range in the axial direction of the first cable 12a, a biased deformation occurs in the axial direction of the first cable 12a, and a plurality of the cables supported by the first cable 12a in which the deflection occurs. The arrangement shape seen from the side of the precast concrete board 21 may vary greatly. The distribution of the amount of water in the containers 30 and 31 arranged along the axial direction of the first cable 12a is adjusted so as to suppress such relative displacement between the precast concrete plates 21.

This adjustment of the amount of water can be performed as follows, for example.
When one segment 23 is sent out and supported on the column 8, the precast concrete plate 21 located below the segment 23, that is, the container 30 placed near the position where the load of the arranged segment 23 acts, From 31, an amount of water corresponding to the weight of the segment 23 is discharged. In this manner, the segments 23 are sequentially arranged, and water is discharged from the containers 30 and 31 placed on the precast concrete plate 21 in the vicinity of the position where the segments 23 are arranged, and the segments 23 are placed in the end block 3. , 4 are arranged.
It should be noted that a predetermined amount of water remains in the containers 30 and 31 after the discharge, and when an inclination occurs in the width direction of the precast concrete board, a difference in water amount between the two containers is provided by these waters. Can be reduced.

By discharging water in response to the load being loaded as described above, the influence of the new load being loaded is reduced. That is, when an amount of water corresponding to the weight of the newly loaded segment 23 is discharged, the total amount of load acting on the first cable 12a hardly changes. In addition, the distribution of the load acting on the first cable 12a by discharging water from the containers 30 and 31 near the loaded position does not vary greatly. Therefore, the bending shape of the first cable 12a does not change greatly.
The amount of water to be discharged is not necessarily an amount corresponding to a newly loaded load, and even if the amount is slightly different, it is possible to suppress a significant change in the shape of the deflection.

  Moreover, as a method of suppressing a large change in the bending shape of the first cable 12a, the method is not limited to the method of discharging water in the containers 30 and 31 in response to a newly loaded load. The water in the containers 30 and 31 can be adjusted by other methods. For example, water discharged from a container near the position where the load is loaded may be distributed to other containers, and the deflection near the position where the load is loaded is prevented from becoming excessive. The water may be poured into another container.

  After arranging the segments 23 constituting the upper girder 9 while adjusting and discharging the water in the containers 30 and 31 as described above, the segments 23 and the end blocks adjacent to each other between the segments 23 and the end blocks 3 and 4 are arranged. Concrete is placed between 3 and 4 to form an upper girder 9 continuous between the end blocks 3 and 4. Also, concrete is placed between the precast concrete plates 21 supported along the first cable 12a and between the precast concrete plates 21 adjacent to the end blocks 3 and 4 and the end blocks 3 and 4. A continuous floor slab 7 is formed between the two end blocks 3 and 4.

As described above, when the upper girder 9 and the suspended floor slab 7 are continuous between the end blocks 3 and 4, the second cable 12 b inserted through the sheath 18 embedded in the precast concrete plate 21 is tensioned to the suspended floor slab 7 along the axis. Introduce direction prestress. Then, the second cable 12 b is fixed to the end blocks 3 and 4.
Further, the nut 17b that has locked the extension cable 14 connected to the first cable 12a to the abutments 1 and 2 is loosened, and the nut 17a screwed to the fixing body 15 at the end of the first cable 12a is used. The end blocks 3 and 4 are made to bear the tensile force of the first cable 12a. Then, when the temporary fixing of the end blocks 3 and 4 is released, the reaction force of the first cable 12 a is transmitted from the end blocks 3 and 4 to the upper beam 9 as an axial force. Thereby, it becomes a structure where both ends are simply supported as shown in FIG. That is, the tensile force acting on the suspended floor slab 7 and the compressive force acting on the upper girder 9 are offset, resulting in a so-called self-contained structure system in which no horizontal force acts on the abutments 1 and 2.

  As described above, when the suspended floor slab 7 is continuous between the end blocks 3 and 4 and the fixing position of the first cable 12a is changed and the structural system becomes independent from the abutments 1 and 2, it remains in the container 30. Drain the water that is running. As a result, the sag of the suspended floor slab 7 is reduced, and prestress is further introduced into the suspended floor slab 7.

  In such a construction method of the upper-floor type suspension floor slab bridge, two containers 30 are arranged on both sides of the center line set in the axial direction of the suspension floor slab bridge on the precast concrete plate 21 supported by the first cable 12a. And when the displacement difference arises in the width direction of the precast concrete board 25, the inclination of the precast concrete board 25 is suppressed by adjusting the water amount difference in the containers 30 and 31 arranged on both sides. Moreover, the fluctuation | variation of the deflection | deviation by the load of a load is reduced by applying a new load, adjusting the quantity of the water stored by the containers 30 and 31 arranged in the axial direction of the 1st cable 12a. Therefore, the upper girder 9 can be formed in a stable state. Moreover, the relative displacement between the adjacent precast concrete plates 21 and the relative displacement between the segments 23 constituting the upper beam girder 9 can be suppressed to a small level, and rebars for connecting them interfere with each other. It is prevented that the precast concrete board 21 is damaged by the interference.

  In addition, in the said embodiment, although containers 30 and 31 are mounted on the precast concrete board 21, even if it suspends and supports the containers 40 and 41 from the precast concrete board 21, as shown in FIG. good. Further, as shown in FIG. 13, when the precast concrete plate 21 is inclined using a member having high bending rigidity, such as a shape steel, as the suspension material, the suspension material 42 is also represented by a virtual line in FIG. It is good also as what produces an angle change with the inclination of the precast concrete board 21. FIG. By supporting the containers 40 and 41 in this manner, the weights of the containers 40 and 41 and the water stored in the containers 40 and 41 act as a force for suppressing the inclination of the precast concrete plate 21. Therefore, the operation of suppressing the inclination by the difference in water amount between the containers 40 and 41 on both sides of the center line becomes easy.

In the embodiment described above, the two containers 30, 31, 40, 41 are arranged on both sides of the center line of the suspended floor slab bridge set in the axial direction of the first cable 12a, but two or more containers are arranged. It may be what you do. Moreover, you may support one container on a centerline. In the case of supporting one container, it is not possible to correct the inclination in the width direction by adjusting the amount of water, but the center of gravity of the member supported by the cable is lowered by the weight of water stored in the container to improve stability. be able to.
When one container is supported on the central portion in the width direction of the precast concrete plate, the container may be placed on the precast concrete plate, or in the center portion in the width direction of the precast concrete plate, an example shown in FIG. The container may be suspended and supported by providing the same hanging bracket as that used in the above.

  When installing one container in the width direction, it is desirable to suspend and support it using two suspending members 43a and 43b locked in the vicinity of both side edges of the precast concrete board 21, as shown in FIG. That is, the two suspension members 43a and 43b, which are coupled at one end to the vicinity of both side edges of the precast concrete board 21, are stretched obliquely downward toward the center in the width direction of the precast concrete board 21, and these are suspended at the center in the width direction. The container is suspended and supported by the suspension material. When the container 42 is suspended and supported and the water is stored in the container 42, the precast concrete plate 21 suspended and supported by the first cable 12a is loaded as shown in phantom lines in FIG. The tension of the suspension members 43a and 43b changes when tilted in the width direction by, for example. That is, the tension of the suspension member 43a coupled to the edge vicinity 21L that is inclined upward is increased, and the tension of the suspension member 43b coupled to the edge vicinity 21R that is downward is decreased. Thereby, the difference in tension between the suspension members 43a and 43b acts to correct the inclination of the precast concrete plate 21, and the lateral stability of the precast concrete plate 21 on which the support column 8 and the like are raised is improved.

When the container is suspended and supported below the precast concrete plate, it can be supported in advance by the precast concrete plate 21 before being arranged along the first cable 12a. For example, in FIGS. As shown, the container can be supported after the precast concrete plate 21 has been placed along the first cable 12a.
In the example shown in FIG. 15, a water storage bag 44 formed of a softly deformable cloth is used as a container. A hole 21b is provided in the center of the precast concrete board 21 in advance, and the water storage bag 44 is lowered below the precast concrete board 21 in a state where water is not accommodated from the hole. A hose 45 is inserted into the water storage bag 44 and water is injected into the water storage bag using the pump 46.

  In the example shown in FIGS. 16 and 17, holes 21c and 21d are provided in the vicinity of both side edges of the precast concrete board, respectively. Then, as shown in FIG. 16A, a single wire 47 is inserted through these holes and connected in an annular shape. A water storage bag 48 is attached to one place of the annular wire 47 on the precast concrete plate 21 as shown in FIG. The water storage bag 48 can be the same as that used in the example shown in FIG. When the water storage bag 48 is attached to the wire 47, the wire 47 is moved in the circumferential direction, and the water storage bag 48 is sent out from the one hole 21d to the lower side of the precast concrete plate 21 as shown in FIG. Then, the wire 47 is further moved in the circumferential direction, and the water storage bag 48 is supported at the substantially center in the width direction below the precast concrete plate 21. At this position, water is injected into the water storage bag 48 by the pump 50 using a hose 49 inserted into the water storage bag 48 as shown in FIG. Further, the wire 47 is fixed to the precast concrete plate 21 so as not to move in the circumferential direction. By supporting the water storage bag 48 in this manner, as in the example shown in FIG. 14, when the precast concrete plate 21 is inclined, a force for restoring the same acts.

As described above, the time when the container is installed on the precast concrete plate 21 may be before the support column 8 is erected on the precast concrete plate 21, or the support column is erected on the precast concrete plate 21. It may be later.
Moreover, the support | pillar 8 may be installed beforehand by the precast concrete board 21, the unit which consists of the precast concrete board 21 and the support | pillar 8 is supported by the 1st cable 12a, and this is followed along the 1st cable 12a. Can be moved and arranged. In this case, you may move along the 1st cable 12a in the state which supported the container 30,31,40,41,42 or the water storage bag 44,48 in which the water was stored by the unit. Compared with the case where only the precast concrete board 21 is arranged, the unit provided with the support column 8 has a higher center of gravity, and the state in which the precast concrete board 21 is supported by the first cable 12a tends to be unstable. By supporting the containers 30, 31, 40, 41, 42 for storing water or the water storage bags 44, 48, the center of gravity is lowered, and stable movement and arrangement are possible.

  In the above-described embodiment, the upper girder 9 is constructed by sequentially arranging the segments 23 of precast concrete, but can also be constructed by placing concrete on site. Even in the case of cast-in-place concrete, the amount of water in the containers 30, 31, 40, and 41 installed on both sides of the center line when the precast concrete plate 21 is inclined in the width direction as the loaded concrete is applied. Adjust the difference. Further, the amount of water in the containers 30, 31, 40, 41, 42 supported in the axial direction of the first cable 12 a or the amount of water in the water storage bags 44, 48 is adjusted. Thereby, the load distribution of the axial direction of the 1st cable 12a can be adjusted, and it can suppress that the arrangement | sequence shape of the precast concrete board 21 when it sees from a side changes.

Moreover, in the said embodiment, since the construction method of the self-supporting type suspension floor slab bridge was mainly demonstrated, the discharge | emission of water and removal of a container are continuous between the end blocks 3 and 4 for the suspension floor slab 7 and the upper road girder 9. After that, prestress is introduced into the suspended floor slab 7. On the other hand, in the case of a suspended floor slab where the suspended floor slab is supported directly on the abutment and the upper girder is supported thereon, the suspended floor slab is formed so as to be continuous between the abutments where the cable is fixed. Later, drain the water and remove the container. Thereby, the amount of deflection of the suspended floor slab is reduced, and prestress can be introduced into the suspended floor slab.
In addition, the construction method of the upper suspension type slab bridge of the present invention can be implemented in various modes within the scope of the present invention, and is not limited to the embodiment described above.

On the other hand, in the construction of a suspended floor slab bridge, the technique of supporting a container containing water on a precast concrete plate supported by a cable can be applied to the following cases.
For example, when the width of the suspended floor slab and the upper girder is wide and the wide concrete plate 51 is supported by the cable 54 and the upper girder 52 is divided and formed in the width direction as shown in FIG. Can be used to maintain directional load balance. That is, when the upper girder 52 is divided by the center line of the suspended floor slab bridge and formed on one edge side, the container 53 is placed on the other edge side, water is contained, and the load on both sides of the center line is reduced. Maintain balance. Thereby, the precast concrete board 51 is supported substantially horizontally, and the construction of the upper road girder 52 becomes possible.

  Also, the method of connecting the suspended floor slab with a wide width, dividing the suspended floor slab with a dividing line along the center line of the suspended floor slab to form two parallel suspended floor slabs, and placing concrete between them in the field Then, the difference in deflection due to the difference in load acting on each of the suspended floor slabs formed by division can be adjusted by a container containing water. That is, as shown in FIG. 19 (a), after two suspended floor slabs 61 and 62 are formed in parallel, when these are connected to form one wide suspended floor slab, If the loads acting on the suspended floor slabs 61 and 62 are different, there is a difference in deflection. On the other hand, by placing the container 63 on the suspended floor slab 62 having a small load and accommodating water, the deflection of the two suspended floor slabs can be made substantially the same as shown in FIG. By placing concrete 64 between the two suspended floor slabs 61, 62 in this state and connecting them, a wide suspended floor slab can be formed. Also, as the load increases as the process of forming the upper girder etc. is performed on the suspended floor slab 62 with a small load after connection, the water in the container 63 is discharged and the wide suspended floor slab is maintained almost horizontal. can do.

1, 2: Abutment, 3, 4: End block, 5, 6: Fence, 7: Suspended floor slab, 8: Post, 9: Upper girder, 10, 11: Earth anchor, 12a: First cable, 12b: Second cable, 13: coupler, 14: extension cable, 15: fixing body, 16: PC steel, 17: nut, 18: sheath embedded in precast concrete plate, 19: lateral connecting member,
20: Ground,
21: Precast concrete board, 22: Steel bar, 23: Segment, 25: Connecting member,
30, 31: container, 32: sensor,
40, 41: Container, 42: Container, 43: Hanging material, 44: Water storage bag, 45: Hose, 46: Pump, 47: Wire, 48: Water storage bag, 49: Hose, 50: Pump

Claims (8)

A suspended floor slab, which is a thin concrete plate-like member formed along a cable stretched between two opposing abutments or piers, and a column erected on this suspended floor slab, and supported on this column A method for constructing an upper-floor type suspension floor slab bridge having an upper girder,
Stretching cables between abutments or piers;
Arranging a plurality of precast concrete plates constituting the suspended floor slab along the cable, and supporting the cable;
Constructing the upper girder on all the precast concrete boards or a column erected from a plurality of selected precast concrete boards;
A step of placing concrete between the precast concrete plates to form the continuous suspended floor slab, and
All or part of the step of constructing the upper girder includes supporting all the precast concrete plates or a plurality of selected precast concrete plates with a container storing water, and precast concrete plates supported by the cables and A method for constructing an upper-floor type suspension floor slab bridge, characterized by adjusting the position of the center of gravity of a member supported by the precast concrete board. A plurality of the containers are arranged in the width direction with respect to the axis of the cable of the precast concrete plate,
The upstream type of claim 1, wherein a difference in water amount between the plurality of containers arranged in the width direction is adjusted so as to reduce an inclination of the precast concrete plate in a direction perpendicular to the axis of the cable. How to construct a suspended floor bridge.   Adjusting the water amount difference, placing the precast concrete plate or the upper road girder substantially horizontally in the width direction, placing concrete between the precast concrete plates to form a continuous suspended floor slab or the upper road girder The method for constructing the upper-floor type suspended floor slab bridge according to claim 2, wherein a step of making the continuous state between both ends of the suspended floor slab is performed.   The adjustment of the water amount difference is performed by installing a sensor that detects a displacement difference or an inclination in a width direction of the precast concrete board and using a pump that is controlled based on a detection result of the sensor. The construction method of the upper-floor type suspension floor slab bridge of Claim 2 or Claim 3.   The said container is suspended and supported below the said precast concrete board, The construction method of the upper-floor type suspended floor slab bridge in any one of Claim 1 to 4 characterized by the above-mentioned. The precast concrete plate is provided with a hole penetrating in the vertical direction,
The container is made of a material that is flexibly deformed,
Passing through the hole from above the precast concrete plate and supporting it below the precast concrete plate,
After that, water is poured into the container, and the construction method of the upper-floor type suspended floor slab bridge according to claim 5   2. The upper suspension type suspended floor according to claim 1, wherein the container is suspended and supported at substantially the center in the width direction of the suspended floor slab by two suspension members joined in the vicinity of both end edges in the width direction of the precast concrete plate. How to build a plate bridge. The column is erected in advance on the precast concrete plate,
The precast concrete plate is supported by the cable, and the container in which water is stored is supported by the precast concrete plate,
The construction method of an upper suspension type slab bridge according to any one of claims 1 to 7, wherein the precast concrete plate is moved along the cable and arranged at a predetermined position.

Images