JP4519029B2 - Anchor fixing method to PC hollow floor slab bridge - Google Patents

Description

  The present invention relates to a method for fixing and fixing an anchor to a hollow floor slab of an existing PC hollow floor slab bridge by post-construction.

Conventionally, as a bridge with a relatively short bridge length, a PC hollow floor slab bridge using a PC (prestressed concrete) hollow floor slab (hereinafter simply referred to as a hollow floor slab) having a hollow inside to reduce the girder weight has been widely adopted. ing.
FIG. 9 shows an example. In the figure, 200 represents a PC hollow floor slab bridge, 202 represents a lower structure such as an abutment and a pier, and 204 represents a hollow floor slab constituting a bridge girder as an upper structure. ing.

The hollow floor slab 204 is formed by embedding a void tube 206 (usually a steel tube), and the void tube 206 has a hollow structure inside.
In the figure, reference numeral 208 denotes a hollow portion, and 210 and 212 denote cover concrete and asphalt pavement surface above the void pipe 206, respectively.

By the way, in the case of existing bridges, there are cases where the seismic standards at the time of construction are not sufficient, and in such cases, it is considered to reinforce them in order to provide sufficient seismic resistance.
As means for reinforcement, it is considered that a fallen bridge prevention device as shown in FIG. 10 is attached, or an elastic bearing device as shown in FIG.

  Here, the falling bridge prevention device 216 shown in FIG. 10 (A) attaches and fixes the fixtures 218 and 220 to the bridge girder 214 and the lower structure 202 such as an abutment and a bridge pier, and a chain (cable Each end of 222 may be connected, and the bridge girder 214 and the lower structure 202 may be connected by the chain 222.

  On the other hand, the falling bridge prevention device 224 shown in FIG. 10 (B) is provided with a stopper block 226 on the lower structure 202 (here, a pier) such as an abutment and a pier, and the fall bridge prevention block 228 is attached to the bridge girder 214 side. By preventing the falling bridge prevention block 228 from hitting the stopper block 226, the falling bridge is prevented.

  On the other hand, FIG. 11A shows an example in which an elastic bearing device is attached. Here, a substantially L-shaped attachment 230 is attached and fixed to the side surface of the lower structure 202, and the attachment 230 and the bridge girder 214 are connected. An elastic bearing device 232 is interposed therebetween, and the upper end portion of the elastic bearing device 232 is fixed to the bridge girder 214, and the lower end portion is fixed to the lower structure 202 via the fixture 230.

  This elastic bearing device 232 elastically supports a horizontal load acting exclusively on the bridge girder 214, and when the bridge girder 214 is relatively displaced in the same direction due to a large horizontal load acting on the bridge girder 214 in the event of an earthquake or the like, Absorbs vibration energy based on the shear elastic deformation of the rubber bearing and attenuates the vibration to prevent the bridge girder from falling.

FIG. 11B shows an example of this type of elastic bearing device disclosed in Patent Document 1 below.
This elastic bearing device 232 has a rubber bearing body 240 in which internal reinforcing plates 236 and rubber layers 238 are alternately stacked, and the lower part is fixed to the lower structure 202 and the upper part is fixed to the bridge girder 214. Intervened between them.

This elastic bearing device 232 does not receive the vertical load of the bridge girder 214 and absorbs the displacement by the shear elastic deformation of the rubber layer 238 when a large horizontal load acts on the bridge girder 214 and the bridge girder 214 is displaced in the same direction. To do.
In the figure, reference numeral 242 denotes a flange plate provided at the upper end of the rubber support 240, and 244 denotes a plate for fixing the flange plate 242 to the bridge beam 214.
Various other elastic bearing devices that receive this type of horizontal load are known.

  Here, the elastic bearing device 232 is mainly described as elastically supporting a horizontal load. However, both the vertical load and horizontal load of the bridge girder 214 are elastically supported by one elastic bearing device. Alternatively, there is also a configuration in which a vertical load is mainly elastically supported, and such an elastic support device can be interposed between the lower structure 202 and the bridge girder 214 for reinforcement.

By the way, when the existing bridge is a steel bridge, the fixing of the mounting tool 218 or the upper part of the elastic bearing device 232 is fixed by making a hole in the lower flange of the steel mold steel that forms the frame of the bridge girder. It can be done relatively easily.
On the other hand, in the case of a concrete bridge, such construction cannot be performed. Therefore, when installing the above-mentioned bridge prevention devices 216 and 224 and the elastic bearing device 232 on an existing bridge, an anchor 246 (see FIG. 12). 10 is fixed to the bridge girder 214, and the fixture 218, the fallen bridge prevention block 228, or the upper portion of the elastic bearing device 232 of FIG. 10 is fixed to the anchor 246.
Therefore, when these fallen bridge prevention devices 216 and 224 and the elastic bearing device 232 are installed in an existing concrete bridge by post-installation, it is necessary to provide such an anchor 246 on the bridge girder 214.

  However, in the case of a PC hollow floor slab bridge, since the hollow floor slab 204 constituting the bridge girder 214 has an internal hollow structure, how to provide the anchor 246 on the hollow floor slab 204 becomes a big problem.

  In the case of such a hollow floor slab 204, usually, as shown in FIG. 12, a hole is formed in the hollow floor slab 204 upward from the lower surface side at a portion between the hollow portions 208 and 208, and an upper portion of the anchor 246 is provided there. Is inserted and fixed with a fixing material such as mortar.

However, in the case of this hollow floor slab 204, the position of the hollow portion 208 itself may deviate from the position of the design drawing, and further, a PC cable which is a lifeline of a PC bridge is located between the hollow portions 208 and 208. Therefore, there is a problem that it is very difficult to drill a hole indicated by an arrow in FIG.
Even if a hole is made, there is a problem that it is difficult to fix and fix the anchor 246 to the hole.

  Therefore, at a portion where the hollow portion 208 is located, an anchor insertion hole penetrating the hollow floor slab 204 from the lower surface to the hollow portion 208 is drilled, and an anchor 246 is inserted into the hollow portion 208 so as to protrude therefrom, and It is conceivable that a fixing material such as mortar is injected into the hollow portion 208 in a fluid state and then cured, whereby the anchor 246 is fixed and fixed in the embedded state (the upper portion is embedded).

  In this way, the position of the anchor insertion hole can be roughly determined to some extent without paying particular attention to the presence and position of the PC cable, and the concrete thickness below the hollow portion 208 in the hollow floor slab 204 is Since it is about 150 to 200 mm, it is possible to easily drill holes, and further, the fixing material can be injected into the hollow portion 206 to fix the anchor 246, so that the fixing material falls downward. Therefore, the anchor 246 can be easily fixed, and sufficient fixing strength can be secured.

  However, the hollow portion 208 in the hollow floor slab 204 is originally provided for weight reduction. Therefore, if a fixing material such as mortar is injected and filled in the entire hollow portion 208, the hollow floor slab 204 is filled. The weight of the bridge is greatly increased, and this causes problems such as adversely affecting the durability and earthquake resistance of the bridge.

JP-A-2005-155221

  With this background, the present invention makes it easy to attach an anchor to a hollow floor slab and does not cause a problem that the weight of the hollow floor slab increases significantly. It was made for the purpose of providing an anchor fixing method to the floor slab.

Thus, according to the first aspect of the present invention, there is provided a method for fixing and fixing an anchor to a hollow floor slab of an existing PC hollow floor slab bridge by post-construction, and (a) the anchor from the lower surface side of the hollow floor slab. A step of inserting into the hollow portion through the anchor insertion hole penetrating to the hollow portion inside the void pipe embedded in the hollow floor slab, and (b) the anchor insertion hole from the end of the void pipe The bag body is inserted into the hollow portion in a contracted state through a bag insertion hole at a position different from the anchor insertion hole, which penetrates to the hollow portion at a position farther than the anchor portion, and then the bag body is inserted into the hollow portion. A step of inflating to form a partition wall in the hollow portion, and (c) in the hollow portion outside the bag body defined between the end of the void tube and the partition wall at the partition wall , injecting a fixing material in a fluid state through the anchor insertion holes and another injection hole and the bag insertion hole A step of embedding a portion of the anchor protruding into the hollow portion into the fixing material, and (d) a step of subsequently curing the fixing material and fixing the anchor to the hollow floor slab. It is characterized by including.

  According to a second aspect of the present invention, in the first aspect, a foamed polyurethane reaction liquid agent is injected into the bag body, the foam body is caused to undergo a foaming reaction, and the bag body is expanded. It is characterized by filling inside.

A third aspect of the present invention is the non-liquid-permeable bag body according to any one of the first and second aspects, wherein the bag body has an aluminum thin film over the entire surface and is flexible and has a predetermined final expansion shape. It is characterized by being.

Effects and effects of the invention

As described above, the present invention inserts a bag body into a hollow portion in a contracted state through a bag insertion hole penetrating to the hollow portion, and then expands the bag body to form a partition portion in the hollow portion, and The fixing material in a fluid state is injected into the hollow portion partitioned by the step and cured, and the protruding portion of the anchor to the hollow portion is fixed and fixed by the fixing material. It is not necessary to inject and cure the fixing material in a fluid state to the entire portion, and it is possible to inject and fix the fixing material partially into the hollow portion over the required range.
Moreover, the partition wall for partitioning the hollow part can be easily formed by simply inserting the bag body into the hollow part in a contracted state and then inflating it.

According to the present invention, it is possible to partially inject and harden the fixing material into the hollow portion over the minimum necessary range, and therefore a large amount of fixing material such as mortar is injected into the hollow portion to form a hollow floor. The weight of the plate is significantly increased, and this does not cause the problem that the durability and the earthquake resistance of the hollow floor plate bridge deteriorate.
Further, since a small amount of fixing material is required, the cost required for the fixing material is made as low as possible, and the construction can be completed in a short construction period.

  In the present invention, the entire portion of the hollow portion partitioned by the partition wall portion can be filled with the fixing material, and in some cases, the fixing material is injected into the hollow portion to a depth corresponding to the protruding height of the anchor. However, it is also possible to leave the upper part of the hollow part as a cavity.

Here, a mortar that is easy to fill and strong in fixing strength can be suitably used as the fixing material, but concrete, resin, or other materials can also be used as the fixing material.
However, it is necessary to use a material having a mechanical property equal to or higher than that of concrete having a compressive strength of 40 N / mm ² so that the anchor can be fixed and fixed with sufficient strength.

  The present invention does not drill holes in a hollow floor slab at a portion between the hollow portions and insert anchors therein and fix and fix them with a fixing material. The anchor is inserted into a state protruding from the hollow portion, and the anchor is fixed and fixed by the fixing material injected into the hollow portion. Therefore, the various advantages described above, that is, the presence and position of the PC cable are particularly important. Without being made, the position of the anchor insertion hole can be roughly determined to some extent, and a hole can be easily drilled in a relatively thin concrete layer below the hollow portion of the hollow floor slab. The anchor can be fixed by injecting the fixing material into the hollow part, so that the anchor can be fixed easily without worrying about the fixing material falling downward, and the fixing strength can be improved. Having both the advantage it is possible to ensure a sufficient strength.

  In the present invention, a foamed polyurethane reaction liquid agent is injected into the bag body, and the bag body is expanded by a foaming reaction inside the bag body. A part can be formed (claim 2).

In this way, the bag body can be firmly fixed to the inner surface of the hollow portion by the expansion pressure, and the fixing material is injected into the hollow portion defined by the partition portion formed by the expanded bag body. Sometimes, it is possible to satisfactorily prevent the bag body from being displaced or moved along the hollow portion.
In addition, since the foamed polyurethane retains a certain shape after foaming, the bag body can be maintained firmly fixed to the inner surface of the hollow portion.

In the present invention, a non-liquid-permeable bag body having an aluminum thin film over the entire surface and having a predetermined final expansion shape can be used as the bag body according to the third aspect.
When such a bag body is used, the entire bag body can be uniformly and satisfactorily expanded by the foaming reaction of the reaction liquid agent inside the bag body. For example, when an elastic bag body such as a rubber balloon is used. Thus, it is possible to avoid the problem that the bag body is ruptured by the action of a partial excessive pressure, and the partition wall portion can be satisfactorily formed with the bag body.

In this case, an aluminum balloon can be suitably used as the bag.
Moreover, this aluminum balloon can use what the said final expansion | swelling shape has comprised the flat disk shape.

  In the present invention, the anchor can be used for mounting a fallen bridge prevention device, or can be used for mounting an elastic bearing device.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a hollow floor slab, in which a void pipe (here, a steel pipe) 14 having a hollow portion 12 is embedded, and the hollow floor slab 10 has an internal hollow structure by embedding the void pipe 14. .
In the same figure, 16 is a covering concrete and 18 is an asphalt pavement surface.
The void tube 14 has an inner diameter of φ650 mm.

FIG. 1 shows a construction completion state. In the figure, reference numeral 20 denotes a partition wall that divides the hollow portion 12, and is configured by filling a foamed polyurethane 24 inside an aluminum balloon (bag body) 22 shown in FIG. .
Here, by forming the partition wall portion 20, the hollow portion 12 is partitioned over a range from the end (left end in the figure) to the distance L (here, L = 500 mm). In the figure, 12A represents the partition space.

  In the present embodiment, the partition wall 20 injects a foamed polyurethane reaction liquid agent into the inside of the aluminum balloon 22 to cause foaming reaction inside to expand the bag body and to fill the foamed polyurethane 24 generated inside the bag body. It is formed by.

In FIG. 1A, 23 is an anchor insertion hole, 25 is an injection hole for fixing material (here, mortar is used), and 28 is a bag insertion hole for inserting an aluminum balloon 22.
Here, the bag insertion hole 28 also serves as an injection hole for injecting the reaction solution into the aluminum balloon 22.

Reference numeral 26 denotes a confirmation hole for confirming whether or not the fixing material has been sufficiently injected into the partition space 12A. The anchor insertion hole 23, the injection hole 25, the bag insertion hole 28, and the confirmation hole 26 are As shown in FIG. 2 (I), each is provided in a form penetrating upward from the lower surface of the hollow floor slab 10 to the hollow portion 12.
The diameter of the anchor insertion hole 23 is about 75 mm here, and the diameters of the other holes, that is, the injection hole 25, the bag insertion hole 28, and the confirmation hole 26 are about 50 mm each.

In FIG. 1, reference numeral 30 denotes an anchor bolt (anchor) made of a deformed steel bar inserted from the anchor insertion hole 22.
The anchor bolt 30 is inserted so as to protrude into the hollow portion 12, and a portion protruding into the hollow portion 12 is embedded in a mortar 32 as a fixing material filled in the partition space 12A. The mortar 32 is fixed and fixed.

Here the anchor bolt 30 is intended overall length _{L 2} is 700 mm, the protruding length _{L 3} from the lower surface of the downward hollow deck 10 is 200 mm.
Further, the position of the upper end is located slightly above the center of the hollow portion 12.

In FIG. 1, reference numeral 34 denotes a flow-in mortar injection pipe, 36 denotes a foamed polyurethane reaction liquid injection pipe, and 38 denotes a confirmation pipe.
However, the injection pipes 34 and 36 and the pipe 38 are cut off from the lower surface of the hollow floor slab 10 after construction as described later, and the remaining parts are left embedded in the hollow floor slab 10. ing.

Next, the construction method of the present embodiment will be described in detail following the procedure.
In this embodiment, first, as shown in FIG. 2 (I), an anchor insertion hole 23, an injection hole 25, and a bag insertion hole penetrating from the lower surface of the hollow floor slab 10 to the hollow portion 12 by a hole drilling machine. 28 and the confirmation hole 26 are drilled.
Next, as shown in FIG. 2 (II), an aluminum balloon 22 as a bag is inserted into the hollow portion 12 through the bag insertion hole 28 in a contracted state.

FIG. 4 shows a state in which the expansion of the aluminum balloon 22 is completed in a free state.
As this aluminum balloon 22, what is marketed with the brand name of a microfoil, for example can be used.
The aluminum balloon 22 has an aluminum thin film over the entire surface, and is inelastic and has only flexibility.
The final expanded shape is determined in advance as a flat disk shape.

Incidentally, in the case of this embodiment, an aluminum balloon 22 having a diameter D at the time of maximum expansion of φ750 mm and a thickness t of 300 mm is used.
The aluminum balloon 22 can be shrunk small, so that it can be easily inserted into the hollow portion 12 from the bag insertion hole 28.

In the present embodiment, the aluminum balloon 22 is set in the injection tube 36 in advance, and when the set is inserted into the hollow portion 12, the liquid A as a reaction liquid agent for foamed polyurethane accommodated in a separate tank. And B liquid (see FIG. 2 (II)) are injected into the aluminum balloon 22 from an injection machine (not shown) through the injection tube 36 to cause a foaming reaction.
Then, the aluminum balloon 22 is expanded to the maximum with the generated foamed polyurethane 24, and at the same time, the foamed polyurethane 24 is filled therein. Here, the partition 20 is formed (FIG. 3 (III)). In this case, the filling amount of the foamed polyurethane 24 is about 5.4 kg in this example.

The bag insertion hole 28 is subjected to a caulking process using a caulking material after the aluminum balloon 22 and the injection tube 36 are inserted. As the caulking material, a urethane-based caulking material can be used.
In this embodiment, a polyol is used as the liquid A (main agent liquid), and an isocyanate is used as the liquid B (curing agent liquid).

Here, the polyurethane foam used for filling the aluminum balloon 22 has a low expansion density of about 30 times and a density after expansion of about 0.08 to 0.13 t / m ^3. The foaming reaction starts in about 15 seconds (20 ° C.) after injection with the liquid B in a mixed state, and the reaction is completed in about one and a half minutes.

As described above, in the present embodiment, as the bag body, the aluminum balloon 22 having only the flexibility without elasticity, in which the final inflated shape in a free state is previously determined to be a flat disk shape, is used.
Thereby, it is possible to fill the inside with the foamed polyurethane 24 and to expand it satisfactorily.

  For example, when a rubber balloon is used as the bag body, if a foamed polyurethane reaction solution is injected into the bag body to cause a foaming reaction, the contact portion of the rubber balloon with the reaction solution or foamed polyurethane will adhere to them. It will be attached, and the attached part will no longer expand.

Therefore, only the part that has not yet been in contact with the reaction liquid agent or polyurethane foam (non-contact part) must be expanded thereafter, and as a result, excessive pressure acts on the non-contact part and the same part bursts. End up.
Alternatively, even if such a rupture does not occur, only the non-contact portion is inflated locally, the expansion shape of the entire rubber balloon becomes an irregular shape, and the cross section of the hollow portion 12 It becomes difficult to close the whole well.

  On the other hand, in the case of the aluminum balloon 22 shown in FIG. 4, since it does not have elasticity in itself, the phenomenon that the non-contact portion to the reaction liquid agent or the polyurethane foam is partially excessively expanded does not occur. While the balloon 22 as a whole expands to a predetermined final shape, the polyurethane foam 24 is uniformly and satisfactorily filled therein.

Further, the aluminum balloon 22 is resistant to heat generated when the reaction liquid agent undergoes a foaming reaction, and there is no problem that a part of the aluminum balloon 22 is ruptured by the heat.
As a result, the aluminum balloon 22 can expand into the final predetermined shape uniformly and satisfactorily with the foaming reaction of the reaction liquid agent, that is, the formation of the polyurethane foam 24, and thus the hollow portion 12 can be expanded. This can be satisfactorily closed over the entire cross section to form a partition wall.

  Next, after the partition wall portion 20 is formed in this way, the anchor bolt 30, the injection pipe 34, and the confirmation pipe 38 are respectively connected to the anchor insertion hole 23 and the injection hole as shown in FIG. Through the hole 25 and the confirmation hole 26, the hollow portion 12 is inserted into the partition space 12A, specifically inside the partition portion 20, and so as to protrude into the partition space 12A.

A nut 40 is screwed into the anchor bolt 30 and the nut 40 is brought into contact with the lower surface of the hollow floor slab 10 so that the anchor bolt 30 is properly vertical in the hollow portion 12, that is, in the compartment space 12A. To protrude.
The confirmation pipe 38 is inserted deeply into the partition space 12A so that the opening at the upper end is located near the top end of the hollow portion 12.
The anchor insertion hole 23, the injection hole 25, and the confirmation hole 26 are respectively subjected to a caulking process with a caulking material in a state where the anchor bolt 30, the injection pipe 34, and the pipe 38 are inserted.
In this state, a mortar 32 in a fluid state as a fixing material is injected from the injection tube 34 into the hollow portion 12, specifically, the partitioned space 12 A partitioned by the partition wall portion 20, and the mortar 32 is filled into the space 12 A.

At this time, if the filling depth of the mortar 32 injected into the partition space 12A exceeds the upper end of the pipe 38, a part of the mortar 32 leaks to the outside through the upper end opening of the pipe 38. It can be confirmed that the mortar 32 in a fluid state is sufficiently filled in the partition space 12A.
Here, the filling volume of the mortar is 0.17 m ³ .

After filling the partition space 12A with the mortar 32 in a fluid state as described above, this is subsequently cured.
The anchor bolt 30 is hardened by the hardening of the mortar 32. Specifically, a portion protruding into the partition space 12A is embedded in the hardened mortar 32. (Fig. 3 (IV)).

Thereafter, as shown in FIG. 3 (V), portions of the injection pipes 34 and 36 and the confirmation pipe 38 protruding from the lower surface of the hollow floor slab 10 are cut off. After the injection pipes 34 and 36 and the pipe 38 are cut, the injection hole 25, the bag insertion hole 28, and the confirmation hole 26 are repaired with water-stopping mortar.
The anchor bolt 30 can be fixedly fixed to the hollow floor slab 10 as described above.
The nut 40 screwed to the anchor bolt 30 is removed from the anchor bolt 30 after fixing with the mortar 32.

Next, FIG. 5 shows another embodiment of the present invention.
In this embodiment, instead of the mortar injection pipe 34, a polyurethane injection pipe 42 is inserted into the injection hole 25, and a reaction liquid agent of polyurethane 44 as a fixing material from the injection pipe 42, that is, a main agent made of polyol. A liquid mixture of liquid A and liquid B consisting of isocyanate is injected and reacted in the compartment space 12A to fill the compartment space 12A with polyurethane 44, and the anchor bolt 30 is fixed and fixed using this as a fixing material. This is an example.

However, the polyurethane 44 as a fixing material is used for fixing and holding the anchor bolt 30 and has a mechanical characteristic equal to or higher than that of concrete having a compressive strength of 40 N / mm ² .
In this case, the filling amount of the polyurethane 44 serving as a fixing material is about 209 kg.
The polyurethane 44 as the fixing material is non-foaming and hard.
The other points are basically the same as those of the embodiment shown in FIGS.

As described above, when the polyurethane 44 or other resin is used as the fixing material, it can be cured in a short time and the required construction time can be shortened.
Further, an increase in the weight of the hollow floor slab 10 due to the fixing material can be minimized.

According to the present embodiment, the fixing material can be partially injected and cured in the hollow portion 12 over the minimum necessary range, and the weight of the hollow floor slab 10 is significantly increased by the injection and curing of the fixing material. Therefore, there is no problem that the durability and earthquake resistance of the bridge are adversely affected.
Further, since a small amount of fixing material is required, the cost is low, and the construction can be completed in a short construction period.

Further, in this embodiment, since the hole is drilled at the position where the hollow portion 12 is located and the anchor bolt 30 is inserted into the hollow portion 12 and fixedly fixed, the presence and position of the PC cable are particularly concerned. In addition, the position of the hole can be determined roughly to some extent, and since the concrete thickness below the hollow portion 12 is relatively thin, the hole can be easily formed.
Further, since the fixing material is injected into the hollow portion 12 to fix the anchor bolt 30, the fixing work of the anchor bolt 32 can be easily performed without worrying about the dropping of the fixing material, and the fixing strength. As a result, sufficient strength can be secured.

FIG. 6 shows an application example of the anchor bolt 30. In this example, the anchor 218 of the falling bridge prevention device 216 in FIG. 10 (A) is fixed to the hollow floor slab 10 as a bridge girder with the anchor bolt 30, In this example, the attachment 218 is connected to the attachment on the lower structure side such as an abutment and a pier (not shown) by a chain 222.
That is, this example is an example in which the fallen bridge preventing device 216 is attached by post-construction with the anchor bolt 30.

On the other hand, the example in FIG. 7 shows an example in which the falling bridge prevention block 228 shown in FIG.
FIG. 8 shows another application example. This example mainly receives the horizontal load, absorbs the vibration energy based on its own horizontal shear elastic deformation, and attenuates the elasticity of FIG. 11B. This is an example in which the support device 232 is fixed to the hollow floor slab 10 with the anchor bolt 30.

The elastic bearing device 232 shown in FIG. 8 is disclosed in Patent Document 1 filed by the applicant of the present application, in which an internal reinforcing plate 236 and a rubber layer 238 are laminated in the vertical direction and integrated by vulcanization adhesion. It has the rubber bearing body 240 of the form.
Here, the rubber bearing body 240 is fixed to the hollow floor slab 10 with the plate 244 and the anchor bolt 30 and the nut 56 screwed therein.
Reference numeral 242 denotes a flange plate, and reference numeral 60 denotes an engagement block that is opposed to the flange plate 242 in a vertical direction and in a horizontal direction (bridge axis direction) in FIG.

The rubber bearing body 240 does not support the vertical load of the hollow floor slab 10, that is, the bridge girder, and when a large load is applied in the horizontal direction, it is sheared and elastically deformed by the horizontal load to attenuate the horizontal displacement. To do.
However, as such an elastic bearing device, it is also possible to use an elastic bearing device that also supports a vertical load or an elastic bearing device that elastically supports only a vertical load.

  Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be implemented in variously modified forms without departing from the spirit of the present invention.

It is a figure which shows the anchor fixing construction method of embodiment of this invention in a construction completion state. It is explanatory drawing of the principal part process of the fixing construction method of the embodiment. FIG. 3 is an explanatory diagram of a main process following FIG. 2. It is a figure which shows the aluminum balloon used in the embodiment. It is explanatory drawing of the principal part process of the anchor fixing construction method of other embodiment of this invention. It is a figure which shows the example of application of the anchor fixed by fixation. It is the figure which showed the application example different from FIG. It is a figure which shows the example of application different from FIG.6 and FIG.7. It is a figure which shows a hollow floor slab bridge and a hollow floor slab. It is a figure which shows an example of a falling bridge prevention apparatus. It is a figure which shows an example of an elastic bearing apparatus. It is a comparative example figure explaining the comparative example with respect to the anchor fixing construction method of this invention.

10 hollow floor slab 12 hollow part 12A partition space 20 partition part 22 aluminum balloon (bag)
23 Anchor insertion hole 24 Polyurethane foam 28 Bag insertion hole 30 Anchor bolt 32 Mortar

Claims (3)

It is a method of anchoring and fixing anchors to the hollow floor slabs of existing PC hollow floor slabs in post-construction.
(A) inserting the anchor into a state of projecting into the hollow portion through an anchor insertion hole penetrating from the lower surface side of the hollow floor slab to the hollow portion inside the void pipe embedded in the hollow floor slab;
(B) The bag body in a contracted state through the bag insertion hole at a position different from the anchor insertion hole, which penetrates from the end of the void tube to the hollow portion at a position farther from the anchor insertion hole. after insertion into the hollow portion, and forming a partition wall in the hollow portion to expand the bag body in the hollow portion
(C) In the hollow portion outside the bag body defined between the end portion of the void tube and the partition wall portion at the partition wall portion, the anchor insertion hole and the bag insertion hole are different from each other. Injecting a fixing material in a fluid state through an injection hole to embed a protruding portion of the anchor into the hollow portion in the fixing material;
(D) a method of fixing an anchor to a PC hollow floor slab bridge, comprising the step of subsequently curing the fixing material and fixing the anchor to the hollow floor slab.   The foamed polyurethane reaction liquid agent is injected into the inside of the bag body, the foamed reaction is caused to expand inside the bag body, and the produced polyurethane foam is filled into the bag body. Anchor fixing method to PC hollow floor slab bridge. 3. The PC according to claim 1, wherein the bag body is a non-liquid-permeable bag body having an aluminum thin film over its entire surface and having a flexible final inflated shape. Anchor fixing method to hollow floor slab bridge.

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