JP2016205098A - Precast floor slab system, bridge structure, precast floor slab system design method, and bridge structure manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast floor slab system being easily constructed from precast floor slabs and improving fatigue durability while preventing the precast floor slab thickness from increasing.SOLUTION: A precast floor slab system 2 comprises: a pair of precast floor slabs 20, which are formed into tabular shape and disposed in an arrangement direction that intersects a thickness direction Z; and a connection part 25, which is disposed between and attached to the pair of precast floor slabs and integrates the pair of precast floor slabs by transmitting bending moment between the pair of precast floor slabs. The elastic modulus of the connection part is smaller than that of the pair of precast floor slabs and the tensile strength of the connection part is higher than that of the pair of precast floor slabs. The adhesive strength of the connection part to adhere to the pair of precast floor slabs is higher than the tensile strength of the pair of precast floor slabs.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a precast slab system, a bridge structure, a precast slab system design method, and a bridge structure manufacturing method.

  In road bridges (bridge structures), floor slabs are used to support asphalt pavement on which automobiles and the like travel. In recent years, the number of road bridges that have deteriorated has increased, and the construction of replacing damaged floor slabs of road bridges has increased. When the floor slab is replaced, the road bridge is closed, but the closed road has a great social impact. For this reason, a method for replacing a floor slab in which the period of traffic restriction is shortened is being studied.

In the road bridge of Patent Document 1, a plurality of precast floor slabs are connected in the direction of the bridge axis of the road bridge to form a floor slab. The precast slab is composed of a main body portion and a joint end portion. The joint end portion is provided on the end side in the bridge axis direction of the precast slab. The joint end portion is configured by repeatedly arranging convex portions and concave portions in the width direction of the road bridge and in the direction perpendicular to the bridge axis perpendicular to the bridge axis direction. A structural reinforcing bar is disposed across the main body and the convex portion. The part which protruded from the end surface of the convex part among structural reinforcing bars is a reinforcing bar for joints. The shape of the joint reinforcing bar is, for example, a loop shape.
A pair of precast slabs arranged adjacent to each other in the bridge axis direction are arranged so that the convex portion of one precast slab faces the concave portion of the other precast slab. It arrange | positions so that the recessed part of one precast floor slab may oppose the convex part of the other precast floor slab. At this time, the joint reinforcing bar of one precast floor slab fits in the recessed part of the other precast floor slab.

When a filling material such as mortar is filled in the gap provided between the recess and the precast floor slab, the pair of precast floor slabs are connected. Below, what connected a pair of precast floor slab is called a precast floor slab system, or it abbreviates as a floor slab system.
The precast floor slab is manufactured in advance at a factory or a place such as a manufacturing yard including a construction site before the installation of the floor slab. For this reason, a precast floor slab can be manufactured irrespective of the weather and the road-blocking regulation of a road bridge.

In the pedestrian bridge of Non-Patent Document 1, recesses are formed on opposite side surfaces of the two precast slabs. One pipe, which is a shear key, is placed in the recess of each precast slab. Fill the pipe with mortar. A space between each recess and the pipe is filled with MMA (Methyl Methacrylate) resin.
As an outline of the design considered when designing the pedestrian bridge, it is described that a resin material is injected between the precast slab and the shear key to expect a continuous slab.

JP 2012-225144 A

Kawada Kogyo Co., Ltd., Toyama Engineering Department, “Design of footbridge using precast floor slab”, [online], January 1990, Kawada Technical Report Vol. 9, [Search March 17, 2015], Internet <URL: http://www.kawada.co.jp/technology/gihou/vol_09.html>

In the floor slab system of Patent Literature 1, the precast floor slabs are securely fixed to each other using a reinforcing bar or a filling material. Hereinafter, the connection structure of such a floor slab system is referred to as a continuous structure. In a continuous structure slab system, the joint of the pair of precast slabs has a shear force in the thickness direction of the precast slab (hereinafter simply referred to as shear force, a direction parallel to the thickness direction of the precast slab). Or a bending moment around an axis parallel to the direction perpendicular to the bridge axis (hereinafter simply referred to as a bending moment, it means a bending moment around an axis parallel to the direction perpendicular to the bridge axis) ) Occurs.
However, it takes a relatively long time to construct (construct) a continuous-structure floor slab system in order to securely fix the precast floor slabs with reinforcing bars or the like.

On the other hand, in the floor slab system of Non-Patent Document 1, precast floor slabs are connected to each other with MMA resin. To connect the precast slabs, simply insert a shear key into the formwork attached to the precast slabs, then pour and harden the MMA resin. For this reason, it does not take a relatively long time to configure the floor slab system.
However, no particular consideration is given to the tensile strength and elastic modulus of the MMA resin main body, the adhesion strength / adhesion shear strength between the precast floor slab and the MMA resin, and the like. In Non-Patent Document 1, it is described that the slab is expected to be continuous in the design outline. This description is described with the intention of transmitting the shearing force between the slabs, and it is confirmed that it is not intended to transmit the bending moment. That is, in the floor slab system of Non-Patent Document 1, it is considered that the MMA resin has a configuration that does not hinder even if the MMA resin is pulled and fractured or peeling occurs between the precast floor slab and the MMA resin. In this slab system, a shearing force is generated but no bending moment is generated in the joint portion of the pair of precast slabs. Hereinafter, the connection structure of such a floor slab system is referred to as a discontinuous structure.

By the way, it is known that the fatigue damage of the floor slab supported by the bridge girder extending in the bridge axis direction is caused by the following mechanism. When a wheel load is applied by a tire or the like from the upper surface side of the floor slab downward, first, a crack extending in the direction perpendicular to the bridge axis is formed on the lower surface of the floor slab. Thereby, the floor slab is divided into a plurality in the bridge axis direction. The floor slab, which was rectangular when viewed in the thickness direction, has a shorter length in the direction of the bridge axis and becomes like a beam.
A crack extending in the direction of the bridge axis is formed on the floor slab, and the crack becomes a tortoiseshell shape. Eventually, the slab will be punched and sheared.

In the floor slab system having a continuous structure, a bending moment is also generated at the joint portion of the pair of precast floor slabs, so that the bending moment is also transmitted to the adjacent precast floor slab. Due to this bending moment, cracks extending in the direction perpendicular to the bridge axis are likely to be formed in the slab.
When the bending moment is not transmitted between precast slabs arranged in the direction of the bridge axis as in a discontinuous structure, the ratio of supporting the wheel load acting on one precast slab with the precast slab on which the wheel load is applied is Get higher. Further, the ratio of supporting the wheel load by the precast slab adjacent to the precast slab in which the wheel load is applied in the bridge axis direction is low. That is, the bending moment around the axis parallel to the bridge axis direction is increased, and the precast slab needs to be thickened.

  The present invention has been made in view of such problems, and can be easily configured from a precast floor slab, and a precast floor slab system that improves fatigue durability while suppressing an increase in the thickness of the precast floor slab. An object of the present invention is to provide a bridge structure provided with this precast slab system. Another object of the present invention is to provide a precast floor slab system design method in which fatigue durability is improved while suppressing an increase in the thickness of the precast floor slab, and a bridge structure using the precast floor slab system design method. It is to provide a manufacturing method.

In order to solve the above problems, the present invention proposes the following means.
The precast floor slab system of the present invention is formed between a pair of precast floor slabs formed in a plate shape and arranged in a direction intersecting the thickness direction, and a pair of the precast floor slabs. A connection portion that is attached to the floor slab and integrates the pair of precast floor slabs by transmitting a bending moment between the pair of precast floor slabs, Less than the elastic modulus of the precast floor slab, the tensile strength of the connection portion is equal to or higher than the tensile strength of the pair of precast floor slabs, and the adhesion strength at which the connection portion adheres to the pair of precast floor slabs is a pair of It is characterized by being not less than the tensile strength of the precast slab.

  The precast floor slab system design method of the present invention is provided between a pair of precast floor slabs that are formed in a plate shape and arranged side by side in a direction intersecting the thickness direction, and the pair of precast floor slabs. A precast floor slab system comprising a pair of connecting portions attached to the precast floor slab, and a design method of the precast floor slab system that integrates the precast floor slab and the connecting portion, wherein the connecting portions Is set to be smaller than the elastic modulus of the pair of precast slabs, the tensile strength of the connecting portion is set to be equal to or higher than the tensile strength of the pair of precast slabs, and the connecting portion is a pair of the precast slabs. The adhesion strength adhered to the floor slab is set to be equal to or higher than the tensile strength of the pair of precast floor slabs, and the pair of precast floor slabs is connected by the connecting portion. It is characterized by transmitting bending moments between.

According to the present invention, the tensile strength of the connecting portion is equal to or higher than the tensile strength of the pair of precast slabs, the adhesive strength of the connecting portion is equal to or higher than the tensile strength of the precast slab, and the elastic modulus is small. Becomes smaller. For this reason, the connection part is less likely to break than the precast floor slab, and the interface between the precast floor slab and the connection part is less likely to break than the precast floor slab.
Further, since the tensile strength and adhesion strength of the connecting portion are set to be equal to or higher than the tensile strength of the precast slab, the bending moment is transmitted without breaking the connecting portion. For this reason, the bending moment transmitted between the pair of precast slabs is increased compared to the bending moment of the floor slab system having a discontinuous structure. As a result, cracks extending in the direction perpendicular to the bridge axis are less likely to be formed in the precast slab compared to the continuous structure, and a certain amount of bending moment is transmitted between the pair of precast slabs. Is suppressed. If cracks extending in the direction perpendicular to the bridge axis are difficult to form on the precast slab, the fatigue durability of the precast slab is improved. When cracks are less likely to be formed, that is, when the floor slab is less likely to be formed into a beam, the effective width of the precast floor slab that can resist the shearing force is increased, so that the punching shear strength is improved.
The floor slab system can be configured by attaching a connecting portion to a pair of precast floor slabs.

Further, in the precast floor slab system, a side surface of the first precast floor slab forming one of the pair of precast floor slabs is provided with a convex portion formed so as to protrude from the side surface of the first precast floor slab. The second precast floor slab that forms the other of the pair of precast floor slabs may be provided with a concave portion that is recessed from the side surface of the second precast floor slab and in which the convex portion is disposed.
According to this invention, when one of the two precast slabs is displaced in the thickness direction, the other of the two precast slabs is also displaced in the thickness direction due to the engagement between the concave portion and the convex portion.

In the precast slab system, the concave portion may be formed in an intermediate portion in the thickness direction on a side surface of the second precast slab.
According to this invention, the convex portion is sandwiched by the second precast slab from both sides in the thickness direction.
In the precast slab system, the convex portion may be formed such that the length in the thickness direction becomes shorter toward the tip side in the direction in which the convex portion protrudes.

The bridge structure of the present invention is characterized by including the precast slab system described above.
Moreover, the manufacturing method of the bridge structure of this invention manufactures the bridge structure provided with the said precast floor slab system using the design method of the precast floor slab system described above.

In the present invention, the precast slab system according to claim 1 can be easily configured from the precast slab, and the fatigue durability can be improved while suppressing an increase in the thickness of the precast slab. According to the method for designing a precast slab system according to claim 6, fatigue durability can be improved while suppressing an increase in the thickness of the precast slab.
According to the precast floor slab system of the second aspect, when one of the precast floor slabs receives a load in the thickness direction, a step in the thickness direction generated between the two precast floor slabs can be suppressed.

According to the precast slab system of the third aspect, the step in the thickness direction generated between the two precast slabs can be more effectively suppressed.
According to the precast floor slab system described in claim 4, the convex portions can be arranged in the concave portions by relatively moving both the precast floor slabs in the direction in which the convex portions protrude.

According to the bridge structure of the fifth aspect, the configuration can be facilitated and the fatigue durability can be improved.
According to the bridge structure manufacturing method of the seventh aspect, it is possible to manufacture a bridge structure with improved fatigue durability while suppressing an increase in the thickness of the precast slab.

It is a perspective view of a road bridge of one embodiment of the present invention. It is sectional drawing of the side surface of the principal part of the road bridge. It is sectional drawing of the precast floor slab system of the modification of one Embodiment of this invention. It is sectional drawing of the precast floor slab system of the modification of one Embodiment of this invention. It is sectional drawing of the precast floor slab system of the modification of one Embodiment of this invention. It is a figure which shows the structure of the precast slab system of an Example, and distribution of a bending moment. It is a schematic diagram explaining the state which the precast slab system of the Example received the load and deform | transformed. It is a figure which shows the structure of the precast slab system which is a continuous structure of a comparative example, and distribution of a bending moment. It is a figure which shows the structure of the precast slab system which is a discontinuous structure of a comparative example, and distribution of a bending moment. It is a figure which shows the change of the bending moment My by the elasticity modulus of the filler of the precast floor slab system of an Example and a comparative example. It is a figure which shows the change of the bending moment Mx by the elasticity modulus of the filler of the precast floor slab system of an Example and a comparative example. It is a figure showing distribution of the stress degree by the position of the direction of a bridge axis where a wheel load acts when the elastic modulus of a filler is 2x10 ³ N / mm ² . When the elastic modulus of the filler is ² × 10N / mm 2, a diagram representing the distribution of the stress intensity by bridge axis direction position acts wheel load. It is a figure which shows the analysis result of the level | step difference of the precast slab adjacent to the bridge axis direction X. FIG. It is a figure which shows the analysis result of the horizontal displacement between the precast slab lower surfaces adjacent to the bridge axis direction X. FIG. It is a figure which shows the state which made the load act on the precast slab system of an Example. It is a figure which shows the state which made the load act on the precast slab system of another Example. It is a perspective view which shows the procedure which constructs the road bridge of one Embodiment of this invention. It is a perspective view which shows the procedure which constructs the road bridge of one Embodiment of this invention. It is a perspective view which shows the procedure which constructs the road bridge of one Embodiment of this invention. It is a schematic diagram of the side surface of the precast slab system in the embodiment of the modification of this invention. It is a perspective view of the precast floor slab system. It is a schematic diagram of the side surface of the precast slab system in the embodiment of the modification of this invention. It is a schematic diagram of the side surface of the precast slab system in the embodiment of the modification of this invention. It is a schematic diagram of the side surface of the precast slab system in the embodiment of the modification of this invention.

Hereinafter, an embodiment of a bridge structure according to the present invention will be described with reference to FIGS. 1 to 24 by taking as an example a case where the bridge structure is a road bridge.
As shown in FIGS. 1 and 2, the road bridge 1 of the present embodiment is a highway bridge on which an automobile C travels, for example. This road bridge 1 includes a bridge pier 10 (only one is shown in FIG. 1) arranged at intervals in the bridge axis direction X, a plurality of bridge girders 15 supported from below by the pier 10, and a plurality of bridge girders 15. And a plurality of precast slabs 20 supported from below.
In addition, the waterproof layer 30 and the asphalt pavement layer 31 which are mentioned later are not shown in FIG.

For the pier 10, RC (Reinforced Concrete), PC (Pressed Concrete), or the like can be used.
The bridge girder 15 extends in the bridge axis direction X and is arranged at a distance from each other in the bridge axis perpendicular direction Y orthogonal to the bridge axis direction X. For example, the bridge axis direction X and the bridge axis perpendicular direction Y are directions parallel to the horizontal plane.
The bridge girder 15 can be made of I-shaped steel or H-shaped steel. The bridge girder 15 is arranged so that the flange 17 is located above and below the web 16. The upper flange 17 is fixed to the precast floor slab 20 with a stopper (not shown). Here, slip stopper means a headed stud, a perforated steel plate gibber, or the like. Although not shown, the lower flange 17 is fixed to a support installed on the pier 10 by a locking bolt or welding.

  As shown in FIGS. 1 and 2, the precast floor slab 20 includes a floor slab body 21 formed in a plate shape, a convex portion 22 provided on a side surface 21 a of the floor slab body 21, and a side surface 21 a of the floor slab body 21. And a recess 23 formed on the side surface 21b on the opposite side. In FIG. 2, one precast slab 20 in the bridge axis direction X corresponds to the first precast slab 20A, and the other precast slab 20 in the bridge axis direction X corresponds to the second precast slab 20B.

The side surface 21a and the side surface 21b are surfaces opposite to each other and are orthogonal to the bridge axis direction X. The side surface 21a and the side surface 21b are each formed flat.
The floor slab body 21 is formed in a rectangular shape when viewed in parallel to the thickness direction Z of the floor slab body 21. The thickness direction Z is a direction orthogonal (crossing) to the bridge axis direction X and the bridge axis perpendicular direction Y, respectively.
The convex part 22 is provided in the intermediate part of the thickness direction Z of the side surface 21a so that it may protrude from the side surface 21a. That is, in a state where the precast floor slab 20 is disposed alone, the side surface 21a is exposed to the outside in one and the other in the thickness direction Z rather than the convex portion 22. The convex portion 22 is formed in an isosceles trapezoidal shape in which the length in the thickness direction Z is shortened toward the distal end side in the direction in which the convex portion 22 protrudes. The convex portion 22 extends in the direction Y perpendicular to the bridge axis. In addition, the convex part 22 may be formed so that it may extend intermittently in the bridge axis perpendicular direction Y.

The concave portion 23 is formed in the middle portion of the side surface 21b in the thickness direction Z so as to be recessed from the side surface 21b. That is, in the state where the precast floor slab 20 is disposed alone, the side surface 21b is exposed to the outside in one and the other in the thickness direction Z rather than the recess 23. The concave portion 23 is formed in an isosceles trapezoidal shape in which the length in the thickness direction Z becomes shorter toward the distal end side in the direction in which the concave portion 23 is recessed. The recess 23 extends in the direction Y perpendicular to the bridge axis. In addition, the recessed part 23 may be formed so as to extend intermittently in the bridge axis perpendicular direction Y corresponding to the protruding part 22.
The convex portion 22 is disposed in the concave portion 23 with a certain gap S between the convex portion 22 and the concave portion 23. The gap S is preferably about 10 mm, for example. The convex portion 22 and the concave portion 23 serve as a so-called concavo-convex shear key.
The plurality of precast slabs 20 are arranged side by side in the bridge axis direction X. The floor slab main body 21 and the convex part 22 are integrally formed by the above-mentioned RC or PC. The length of the precast floor slab 20 in the bridge axis direction X is, for example, 2 to 3 m.

Between the precast slabs 20 adjacent to each other in the bridge axis direction X, a filler (connecting portion) 25 is provided. In addition, the precast floor slab system 2 of this embodiment is composed of the filler 25 and a pair of precast floor slabs 20 adjacent to each other in the bridge axis direction X with the filler 25 interposed therebetween. The filler 25 is filled in the gap S and attached to the precast floor slab 20 respectively.
The elastic modulus (elastic coefficient) of the filler 25 is smaller than the elastic modulus of the precast floor slab 20. When the precast floor slab 20 is formed of PC, the elastic modulus of the precast floor slab 20 is, for example, 2 × 10 ⁴ to 4 × 10 ⁴ N / mm ² (Newton per square millimeter) (2 × 10 ⁴ to 4 × 10 ⁴ MPa (megapascal)).

The lower limit of the elastic modulus of the filler 25 is within a range in which the filler 25 transmits a bending moment between the precast slabs 20 or a step difference between precast slabs adjacent to the bridge axis direction X described later is a predetermined value. Is set within a range that does not increase.
The lower limit value of the elastic modulus of the filler 25 is, for example, 1 × 10 N / mm ² . One reason for this is that the elastic modulus of rubber is about 1 × 10 to 10 × 10 N / mm ² , and it is difficult to consider using a material having a smaller elastic modulus than rubber in the field of civil engineering.
Another reason for this is that when a material having a smaller elastic modulus than rubber is used, the steps between adjacent precast slabs become large.

The tensile strength (tensile strength) of the filler 25 is equal to or higher than the tensile strength of the precast floor slab 20. Tensile strength means the value of the maximum tension that a material can withstand divided by the (initial) cross-sectional area of the material.
The adhesion strength at which the filler 25 adheres to the precast floor slab 20 is equal to or higher than the tensile strength of the precast floor slab 20. The adhesion strength between the first material and the second material is determined when the second material is moved relative to the first material along the contact surface between the first material and the second material. This means a value obtained by dividing the maximum value of the pulling force or the punching force by the area of the contact surface.

In a state where one side surface 21a and the other side surface 21b of a pair of precast floor slabs 20 adjacent to each other in the bridge axis direction X are opposed to each other, the other convex portion 22 is disposed in one concave portion 23. When one of the pair of precast floor slabs 20 is displaced in the thickness direction Z, the concave portion 23 and the convex portion 22 are engaged in the thickness direction Z, and the other is also displaced in the thickness direction Z.
Since the concave portion 23 is formed at an intermediate portion in the thickness direction Z of the side surface 21 b, the convex portion 22 of one precast floor slab 20 is sandwiched in the thickness direction Z by the other precast floor slab 20.
Since the convex portion 22 is formed so that the length in the thickness direction Z becomes shorter toward the distal end side, the convex portion 22 is formed in the concave portion 23 by bringing the pair of precast floor slabs 20 closer to the bridge axis direction X. Is placed.

  The road bridge 1 is formed by sequentially laminating a known waterproof layer 30, asphalt pavement layer 31 and the like on the precast floor slab system 2. As the tire C1 of the automobile C moves on the asphalt pavement layer 31 in the bridge axis direction X, a wheel load F1 directed downward is applied to the floor slab system 2.

Here, a configuration of a modified example of the floor slab system 2 will be described.
The precast floor slab 35 of the floor slab system 2 </ b> A shown in FIG. 3 is provided with a convex portion 36 and a concave portion 37 instead of the convex portion 22 and the concave portion 23 of the precast floor slab 20. The convex portion 36 and the concave portion 37 are each formed in a semi-cylindrical shape. In addition, the shape of the convex part 36 and the recessed part 37 is not limited to a semi-cylindrical shape, The shape which made the bottom part the shape which made the ellipse half the columnar shape may be sufficient.
The precast floor slab 40 of the floor slab system 2 </ b> B shown in FIG. 4 has a configuration in which the convex portion 22 and the concave portion 23 are not provided in the precast floor slab 20. The side surface 21 a and the side surface 21 b are each formed flat regardless of the position in the thickness direction Z of the floor slab body 21.
A precast floor slab 45 of the floor slab system 2 </ b> C shown in FIG. 5 has a concave portion 46 having the same shape as the concave portion 23 instead of the convex portion 22 of the precast floor slab 20. That is, recesses 23 and 46 are respectively formed on the side surfaces of the floor slab body 21 that are opposite to each other.
A connection member 48 formed in a hexagonal column shape is disposed in the recesses 23 and 46. The connecting member 48 may be a steel pipe having a hexagonal cross section filled with mortar, or may be formed of RC or PC. The connecting member 48 is disposed in the filler 25. In addition, the shape of the connection member 48 is not limited to a hexagonal columnar shape, and may be a columnar shape having a bottom or a rectangular shape.
The pair of precast floor slabs 45 and connecting members 48 form a so-called three-piece type shear key.

  Next, the configurations of the floor slab system of the example of this embodiment and the floor slab system of the comparative example and the distribution of two types of bending moments will be described.

  FIG. 6 shows the configuration of the floor slab system 3 of this embodiment including the precast floor slabs 20, 20 </ b> C, 20 </ b> D and the filler 25 and the distribution of two types of bending moments. 6A is a plan view of the floor slab system 3, FIG. 6B is a side sectional view of the floor slab system 3, and FIG. 6C is a front sectional view of the floor slab system 3. FIG. FIG. 6D shows the distribution of the bending moment My around the axis parallel to the direction Y perpendicular to the bridge axis acting on the slab system 3. FIG. 6 (e) shows the distribution of the bending moment Mx around the axis parallel to the bridge axis direction X acting on the floor slab system 3.

The precast floor slab 20 </ b> C has no protrusions 22 formed on the precast floor slab 20. The precast floor slab 20 </ b> D has no concave portion 23 formed on the precast floor slab 20.
The floor slab system 3 is supported from below by bridge girders 15 at both ends in the direction Y perpendicular to the bridge axis.
A load F2 is applied downward to a position P1 on the upper surface of the precast floor slab 20 that is the center in the bridge axis direction X and the center in the bridge axis perpendicular direction Y. In this case, the bending moment My at each position in the bridge axis direction X of the floor slab system 3 is as shown in FIG. In the precast floor slab 20 of the floor slab system 3, the bending moment Mx at each position in the direction Y perpendicular to the bridge axis is as shown in FIG.

When the slab system 3 receives the load F2, as shown in FIG. 7, the upper surface 21c side of the deck body 21 a force F ₁₁ to try to compress the filling material 25 in the Hashijiku direction X acts. A force F ₁₂ that causes the filler 25 to be pulled in the bridge axis direction X acts on the lower surface 21 d side of the floor slab body 21. Since the elastic modulus of the filler 25 is smaller than the elastic modulus of the precast floor slab 20, the strain of the filler 25 in the bridge axis direction X is larger than the strain of the precast floor slab 20. Since the filler 25 is deformed more greatly than the precast slab 20, the stress degree σ ₂ generated in the filler 25 in the bridge axis direction X rather than the stress degree (stress) σ ₁ generated in the precast slab 20 Is smaller. That is, the stress in the bridge axis direction X is relaxed by the filler 25.
The filler 25 is deformed to a greater extent than the precast floor slab 20, but the tensile strength of the filler 25 is equal to or higher than the tensile strength of the precast floor slab 20, and the adhesion strength at which the filler 25 adheres to the precast floor slab 20 is It is higher than the tensile strength of the plate 20. For this reason, the filler 25 is less likely to break than the precast floor slab 20, and the interface 2a between the precast floor slab 20 and the filler 25 is less likely to break than the precast floor slab 20.
In addition, the description which compared the bending moments Mx and My in the floor slab system 3 of a present Example with the bending moments Mx and My of a comparative example is the description of the structure of the floor slab system of a comparative example, and distribution of two types of bending moments. To do after.

  FIG. 8 shows, as a comparative example, the configuration of the continuous structure floor slab system 100 of Patent Document 1 described above and the distribution of two types of bending moments. 8 (a) to 8 (e) show the objects of the configuration or the distribution of bending moments Mx and My in FIGS. 6 (a) to 6 (e) from the floor slab system 3 of the embodiment to the floor slab system of the comparative example. These are shown in place of 100.

In the floor slab system 100, the precast floor slabs 110A, 110B, and 110C are arranged side by side in the bridge axis direction X, and between the precast floor slab 110A and the precast floor slab 110B, and between the precast floor slab 110B and the precast floor slab 110C. A filling material 115 is provided.
The precast floor slab 110 </ b> A has a floor slab body 111 configured in the same manner as the floor slab body 21. A notch 111a is formed at an end of the slab body 111 on the precast floor slab 110B side in the bridge axis direction X. A joint reinforcing bar 112 protrudes from the notch 111a.
In the precast floor slab 110B, in addition to the components of the precast floor slab 110A, a notch 111b is formed at an end of the floor slab body 111 in the bridge axis direction X on the precast floor slab 110A side. A joint reinforcing bar 113 protrudes from the notch 111a.
In the precast floor slab 110C, the notch 111a is not formed in the floor slab body 111 and the joint reinforcing bar 112 is not provided in the floor slab body 111 with respect to each configuration of the precast floor slab 110B.

A plurality of distribution reinforcing bars 114 are arranged so as to extend in the direction Y perpendicular to the bridge axis so as to engage with the joint reinforcing bar 112 of the precast floor slab 110A and the joint reinforcing bar 113 of the precast floor slab 110B, respectively (FIG. (See the enlarged view in 8 (b)).
By filling the notch 111a of the precast floor slab 110A and the notch 111b of the precast floor slab 110B with the filling material 115 such as mortar, the joint reinforcing bars 112 and 113 are embedded in the filling material 115, and the precast floor slab 110A and precast floor slab 110B are connected. The same applies to the precast floor slab 110B and the precast floor slab 110C.
That is, the floor slab system 100 of the comparative example forms notches 111a and 111b in place of the filler 25 with respect to the floor slab system 3 of the embodiment, and the joint reinforcing bars 112 and 113 and the padding material. 115 is provided.
In addition, in the floor slab system 100 having a continuous structure, it is necessary to dispose power distribution reinforcing bars between precast slabs for construction. For this reason, the work time required to construct the floor slab system 100 from the precast floor slab increases more than the work time of the floor slab system 3 of the present embodiment.

The floor slab system 100 is supported from below by bridge girders 15 at both ends in the direction Y perpendicular to the bridge axis.
A load F2 is applied downward to a position P1 that is the center of the bridge axis direction X and the center of the bridge axis perpendicular direction Y on the upper surface of the precast slab 110B. In this case, the bending moment My at each position in the bridge axis direction X of the floor slab system 100 is as shown in FIG.
In the precast floor slab 110B of the floor slab system 100, the bending moment Mx at each position in the direction Y perpendicular to the bridge axis is as shown in FIG.
In the continuous structure floor slab system 100, the precast floor slabs are securely fixed to each other by the joint reinforcing bars 112 and 113 and the padding material 115. For this reason, as shown in FIG. 8D, the bending moment My generated in the joint portion by the load F2 applied to the precast slab 110B is the bending moment generated in the joint portion by the load F2 shown in FIG. It is larger than the moment My.

That is, in the floor slab system 3 of the present embodiment, the bending moment My is smaller than that of the continuous structure floor slab system 100 of the comparative example. For this reason, in the floor slab system 3 of the present embodiment, cracks extending in the direction Y perpendicular to the bridge axis are less likely to be formed as compared to the floor slab system 100 of the continuous structure of the comparative example. Hereinafter, such a connection structure by the filler 25 of the floor slab system 3 of this embodiment is referred to as a semi-continuous structure.
In the continuous structure floor slab system 100, the bending moment My is decreased compared to the semi-continuous structure floor slab system 3 because the bending moment My is increased compared to the semi-continuous structure floor slab system 3.

  FIG. 9 shows, as a comparative example, the configuration of the floor slab system 101 having the non-continuous structure of Non-Patent Document 1 described above and the distribution of two types of bending moments. 9 (a) to 9 (e) show the objects of the configuration or the distribution of bending moments Mx and My in FIGS. 6 (a) to 6 (e) from the floor slab system 3 of the embodiment to the floor slab system of the comparative example. They are shown in place of 101.

In the floor slab system 101, the precast floor slabs 120A, 120B, and 120C are arranged side by side in the bridge axis direction X, and between the precast floor slab 120A and the precast floor slab 120B, and between the precast floor slab 120B and the precast floor slab 120C. A filling material 125 is provided.
The precast floor slabs 120A, 120B, and 120C are configured in the same manner as the floor slab body 21. The filling material 125 is made of MMA resin.
That is, the floor slab system 101 of the comparative example is provided with a filling material 125 instead of the filler 25 with respect to the floor slab system 3 of the example.

In the floor slab system 101, both ends of the bridge axis perpendicular direction Y are supported by bridge girders 15 from below.
A load F2 is applied downward to a position P1 that is the center in the bridge axis direction X and the center in the bridge axis perpendicular direction Y on the upper surface of the precast slab 120B. In this case, the bending moment My at each position in the bridge axis direction X of the floor slab system 101 is as shown in FIG.
In the precast floor slab 120B of the floor slab system 101, the bending moment Mx at each position in the bridge axis perpendicular direction Y is as shown in FIG.
In the floor slab system 101 having a non-continuous structure, the precast floor slabs are connected to each other by a filling material 125. The interlining material 125 is not guaranteed to have sufficient strength against the tensile force generated in the interim material 125 itself or the peeling force from the precast floor slab. For this reason, there is a possibility that the interlining material 125 may be tensile-destructed or peeling may occur between the precast floor slab and the interlining material 125. Then, as shown in FIG. 9D, even when the load F2 applied to the precast floor slab 120B is applied, the bending moment My is not generated in the joint portion. The bending moment My of the discontinuous structure slab system 101 is greatly reduced as compared to the bending moment My of the continuous structure floor slab system 100.

  In the floor slab system 3 having a semi-continuous structure according to this embodiment, the tensile strength of the filler 25 is equal to or higher than the tensile strength of the precast floor slab 20, and the adhesion strength of the filler 25 is equal to or higher than the tensile strength of the precast floor slab 20. By transmitting the bending moment My without breaking the filler 25, the bending moment My transmitted between the pair of precast floor slabs of the semi-continuous floor slab system 3 is the same as that of the floor slab system 101 of the discontinuous structure. It increases compared with the bending moment My transmitted between a pair of precast slabs. Thus, in the floor slab system 3 of the semi-continuous structure of the present embodiment, the pair of precast slabs 20 are integrated by transmitting the bending moment My between the pair of precast slabs 20 by the filler 25. The term “integration” as used herein refers to a pair of fillers 25 so that the filler 25 does not break before the precast floor slab 20 when a load of an automobile level is applied in the thickness direction Z of the floor slab system 3. This means that the precast floor slabs 20 are connected together so that they cannot be separated. Furthermore, the term “integration” means that when a load of the level of an automobile acts in the thickness direction Z of the floor slab system 3, the stress acting on the filler 25 is smaller than the tensile strength of the filler 25, and the filler 25 is It means that it is smaller than the adhesion strength that adheres to the precast slab 20.

In the discontinuous structure floor slab system 101, the bending moment My is increased compared to the semi-continuous structure floor slab system 3 because the bending moment My is decreased compared to the semi-continuous structure floor slab system 3.
In the floor slab system 3 having a semi-continuous structure according to the present embodiment, the bending moment Mx can be suppressed as compared with the floor slab system 101 having a non-continuous structure. Therefore, the floor slab system 3 can suppress an increase in the thickness (length in the thickness direction Z) of the precast floor slabs 20, 20C, and 20D as compared with the floor slab system 101 having a discontinuous structure. That is, it is possible to control the precast floor slabs 20, 20C, and 20D so as not to increase in thickness.

  In the semi-continuous floor slab system 3 of the present embodiment, the filler 25 integrates a pair of precast floor slabs 20, and the filler 25 is less likely to break than the precast floor slab 20. Unlike the floor slab system of Non-Patent Document 1, in this embodiment, the structure is based on the premise that the pair of precast floor slabs 20 are integrated without breaking the filler 25.

  Further, in the design method of the floor slab system 3 of the present embodiment, the elastic modulus of the filler 25 is set to be smaller than the elastic modulus of the precast floor slab 20. Furthermore, the tensile strength of the filler 25 is set to be equal to or higher than the tensile strength of the precast floor slab 20. The adhesion strength of the filler 25 is set to 20 or more of the tensile strength of the precast slab. And the precast floor slab 20 is integrated by transmitting the bending moment My between the precast floor slabs 20 with the filler 25.

  Next, the structure and analysis result of the floor slab system of the Example of this embodiment and the floor slab system of a comparative example are demonstrated.

(Analysis result 1)
The results of analyzing changes in two types of bending moments depending on the elastic modulus of the filler of the floor slab system of the example and the comparative example will be described with reference to FIGS.
The bending moment My is a value at the center in the bridge axis direction X of the precast slab, and the bending moment Mx is a value at the center in the bridge axis perpendicular direction Y of the precast slab. The values of the moments My and Mx and the length of the precast slab in the bridge axis direction X increase as they approach the tip side of the arrow in the figure.
10 and 11, the analysis results indicated by ● are the analysis results of the floor slab system having a continuous structure of the comparative example. In the floor slab system of this comparative example, the elastic modulus of the filler 25 in FIG. 6 is made equal to the elastic modulus of the precast floor slabs 20, 20C, 20D, and the precast floor slabs are virtually continuously connected in the bridge axis direction X. It is what was in the state.
On the other hand, the analysis results indicated by the ▲, ▼, and △ marks use a model in which the elastic modulus of the filler 25 in FIG. 6 is smaller than the elastic modulus of the precast slabs 20, 20C, 20D. It is. The elastic modulus of the filler 25 used in the analysis result model is indicated by ▲, ▼, and Δ in descending order.

It has been found that the bending moment My acting on the precast slab shown in FIG. 10 decreases as the elastic modulus of the filler decreases regardless of the length of the precast slab in the direction perpendicular to the bridge axis Y. That is, it was found that cracks extending in the direction perpendicular to the bridge axis Y are less likely to be formed in the precast slab as the elastic modulus of the filler decreases.
On the other hand, it can be seen that the bending moment Mx acting on the precast slab shown in FIG. 11 increases as the elastic modulus of the filler decreases, regardless of the length of the precast slab in the direction perpendicular to the bridge axis Y. It was.

(Analysis result 2)
The result of analyzing the change in the degree of stress acting on the precast slab depending on the position of the wheel load in the bridge axis direction X in the floor slab system of the embodiment will be described with reference to FIGS. In addition, based on this analysis result, the filler, ie, the material used as a connection part, is demonstrated.
FIG. 12A is a diagram showing a distribution of the degree of stress acting on the upper surface 21c and the lower surface 21d of the floor slab body 21 of the precast floor slab 20 shown in FIG. FIG. 12B is a diagram showing the distribution of the degree of stress acting on the upper surface 25a and the lower surface 25b of the filler 25 shown in FIG. FIG.12 (c) is a figure showing distribution of the stress degree which acts on the upper end 2b and the lower end 2c of the interface 2a of the precast slab 20 and the filler 25 shown in FIG.

For example, when the wheel load F1 is applied to the position N1 in the bridge axis direction X shown in FIG. 2, a compressive stress level having a distribution as indicated by the line L1 is applied to the upper surface 21c of the precast floor slab 20. That is, on the upper surface 21c, the magnitude of the stress level at the position N1 is the largest, and the stress level approaches 0 as the distance from the position N1 in the bridge axis direction X increases.
On the other hand, when the wheel load F1 is applied to the position N1, the tensile stress level distributed as shown by the line L11 acts on the lower surface 21d of the floor slab body 21 of the precast floor slab 20. That is, on the lower surface 21d, the magnitude of the stress level at the position N1 is the largest, and the stress level approaches 0 as the distance from the position N1 in the bridge axis direction X increases.

Positions A1 and A2 shown in FIGS. 2 and 12 (a) are positions where the filler is arranged in the bridge axis direction X. Between the position A1 and the position A2 is a range A3 in which one precast floor slab is arranged. In FIG. 12A, the compressive stress level is indicated by a positive value, and the tensile stress level is indicated by a negative value.
The position where the wheel load F1 acts is moved to positions N1, N2,..., N8 in the bridge axis direction X. The position N4 is the position closest to the position A1 where the filler is disposed.
The analysis conditions of the analysis results shown in FIG. 12 were that the elastic modulus of the precast slab was 2 × 10 ⁴ N / mm ² and the elastic modulus of the filler was 2 × 10 ³ N / mm ² . That is, the elastic modulus of the filler was set to 1/10 of the elastic modulus of the precast slab.
Lines L1, L2,..., L8 represent the distribution in the bridge axis direction X of the stress acting on the upper surface 21c of the floor slab body 21 when the positions where the wheel load F1 acts are N1, N2,. Represent. Lines L11, L12,..., L18 represent the distribution in the bridge axis direction X of the degree of stress acting on the lower surface 21d of the floor slab body 21 when the position where the wheel load F1 acts is N1, N2,. Represent.

  The size of the wheel load F1 and how it is to be applied was determined based on the Road Bridge Specification / Explanation (Japan Road Association, March 2012).

It can be seen that the stress level represented by the line L4 when the position where the wheel load F1 acts becomes N4 is smaller than the stress level represented by the lines L1 to L8 other than the line L4. This is because the position where the wheel load F1 acts approaches the position A1 where the filler is disposed, and the degree of stress is hardly transmitted in the bridge axis direction X.
It can be seen that the magnitude of the stress level represented by the line L14 is also smaller than the magnitude of the stress level represented by the lines L11 to L18 other than the line L14.

In FIG. 12B, a line L21 represents the degree of stress of the upper surface 25a of the filler 25. A line L22 represents the stress level of the lower surface 25b of the filler 25. In the stress level of the filler on the vertical axis, a positive value indicates a tensile stress level and a negative value indicates a compressive stress level.
A line is drawn down to the side of FIG. 12 (b) without changing the position in the bridge axis direction X from the position N1 in FIG. 12 (a), and the stress on the vertical axis in FIG. 12 (b) corresponding to the intersection with the line L21 Read. Thereby, it can be seen that the stress degree σ1 of the upper surface 25a of the filler 25 when the wheel load F1 acts on the position N1 is about 0.3 N / mm ² (tensile stress degree).
Similarly, the stress level on the vertical axis in FIG. 12B corresponding to the intersection of the line L22 and the line drawn from the position N1 in FIG. 12A without changing the position in the bridge axis direction X is read. Thereby, it can be seen that the stress degree σ11 of the lower surface 25b of the filler 25 when the wheel load F1 is applied to the position N1 is about −0.3 N / mm ² (compression stress degree). It can be seen that the stress σ4 of the upper surface 25a of the filler 25 when the wheel load F1 is applied to the position N4 is about 2.3 N / mm ² . It can be seen that the stress σ14 of the lower surface 25b of the filler 25 when the wheel load F1 is applied to the position N4 is about −2.6 N / mm ² .

Among the fillers 25, the upper surface 25a and the lower surface 25b are places where the range in which the degree of stress changes is greatest. From FIG. 12 (b), it was found that the stress level of the filler when the position where the wheel load F1 acts changes in a range of about −2.6 to 2.3 N / mm ² .

Resin, rubber, and the like change their physical property values depending on additives, grades, and the like, and the elastic modulus, tensile strength, and adhesion strength listed below are examples.
Examples of materials that can be used as a filler having an elastic modulus close to 2 × 10 ³ N / mm ² include acrylic resin mortar and epoxy resin. For example, the elastic modulus of acrylic resin mortar is 0.8 × 10 ³ N / mm ² , and the elastic modulus of epoxy resin is 3.0 × 10 ³ N / mm ² . The tensile strength (σt) of the acrylic resin mortar is 5.0 N / mm ² , and the tensile strength of the epoxy resin is 9.0 to 60 N / mm ² . In addition, the compressive strength of the acrylic resin mortar and the epoxy resin is sufficiently smaller than −5 N / mm ² . That is, the acrylic resin mortar and the epoxy resin can resist the stress level of the filler in the range B1 shown in FIG.
It was found that the acrylic resin mortar and the epoxy resin can resist the stress level of the filler acting by the wheel load F1.

In FIG. 12C, a line L26 represents the degree of adhesion stress at the upper end 2b of the interface 2a between the precast floor slab and the filler 25. A line L27 represents the degree of adhesion stress at the lower end 2c of the interface 2a between the precast floor slab and the filler 25.
The line is lowered to the side of FIG. 12C without changing the position in the bridge axis direction X from the position N1 in FIG. 12A, and the degree of adhesion stress on the vertical axis in FIG. 12C corresponding to the intersection with the line L26. I Read. Thus, it can be seen that the degree of adhesion stress τ1 of the upper end 2b of the interface 2a when the wheel load F1 is applied to the position N1 is about 0.3 N / mm ² .
Similarly, the degree of adhesion stress on the vertical axis in FIG. 12C corresponding to the intersection of the line L27 and the line drawn from the position N1 without changing the position in the bridge axis direction X is read. Thus, it can be seen that the degree of adhesion stress τ11 at the lower end 2c of the interface 2a when the wheel load F1 is applied to the position N1 is about −0.3 N / mm ² .
It can be seen that the degree of adhesion stress τ4 at the upper end 2b of the interface 2a when the wheel load F1 is applied to the position N4 is about 2.4 N / mm ² . It can be seen that the degree of adhesion stress τ14 at the lower end 2c of the interface 2a when the wheel load F1 is applied to the position N4 is about −2.8 N / mm ² .

Among the interface 2a, the upper end 2b and the lower end 2c are places where the range in which the adhesion stress changes is greatest. From FIG. 12 (c), it was found that the degree of adhesion stress of the interface 2a when the position where the wheel load F1 acts changes in the range of about −2.8 to 2.4 N / mm ² .

For example, the adhesive strength of acrylic resin mortar (σg) is 2.0 N / mm ^2, the adhesive strength of the epoxy resin is 6.0 N / mm ^2. That is, the acrylic resin mortar can resist the adhesion stress in the range B2 shown in FIG. 12C of −2.0 to 2.0 N / mm ² , and the epoxy resin has a resistance of −6.0 to 6.0 N / mm ² . It can resist the adhesion stress degree in the range B3.
It was found that the epoxy resin can resist the adhesion stress degree of the interface 2a acting by the wheel load F1.

As described above, it has been found that an epoxy resin is used as a filler having a modulus of elasticity close to 2 × 10 ³ N / mm ² .

The analysis conditions of the analysis results shown in FIG. 13 were that the elastic modulus of the precast slab was 2 × 10 ⁴ N / mm ² and the elastic modulus of the filler was 2 × 10 N / mm ² . That is, the elastic modulus of the filler was set to 1/1000 of the elastic modulus of the precast slab.
13 (a), 13 (b), and 13 (c) show the elastic modulus of the filler in FIG. 12 (a), FIG. 12 (b), and FIG. 12 (c) to 2 × 10 N / mm ² . It is a figure which shows the replaced analysis result.
Lines L31, L32,..., L38 in FIG. 13A are bridge axes of the degree of stress acting on the upper surface 21c of the floor slab body 21 when the position where the wheel load F1 acts is N1, N2,. Each distribution in the direction X is represented. Lines L41, L42,..., L48 represent the distribution in the bridge axis direction X of the stress acting on the lower surface 21d of the floor slab body 21 when the position where the wheel load F1 acts is N1, N2,. Represent.

  Regarding the stress level acting on the upper surface 21c, which is the compressive stress level, the magnitude of the stress level represented by the line L34 when the position where the wheel load F1 is applied is N4 is other than the line L34 among the lines L31 to L38. It can be seen that it is smaller than the magnitude of the stress represented by. This tendency is more prominent than the degree of stress in FIG. This is because the elastic modulus of the filler is further reduced, and the position where the wheel load F1 acts is closer to the position A1 where the filler is disposed, and the degree of stress is less easily transmitted in the bridge axis direction X. .

In FIG. 13B, a line L51 represents the degree of stress of the upper surface 25a of the filler 25. A line L52 represents the degree of stress of the lower surface 25b of the filler 25.
A line is drawn down to the side of FIG. 13B without changing the position in the bridge axis direction X from the position N4 in FIG. 13A, and the stress on the vertical axis in FIG. 13B corresponding to the intersection with the line L51 is expressed. Read. Thereby, it can be seen that the stress degree σ34 of the upper surface 25a of the filler 25 when the wheel load F1 is applied to the position N4 is about 0.3 N / mm ² (tensile stress degree). Similarly, it can be seen that the stress level σ44 of the lower surface 25b of the filler 25 when the wheel load F1 is applied to the position N4 is about −0.3 N / mm ² (compression stress level).
From FIG. 13 (b), it was found that the stress level of the filler when the position where the wheel load F1 acts changes in a range of about −0.3 to 0.3 N / mm ² .

Rubber is an example of a material that can be used as a filler having an elastic modulus close to 2 × 10 N / mm ² . For example, the elastic modulus of rubber is 1 × 10 to 10 × 10 N / mm ² . The rubber has a tensile strength (σt) of 5 to 25 N / mm ² . Note that the compressive strength of rubber is sufficiently smaller than −5 N / mm ² . That is, the rubber can resist the stress level of the filler in the range B5 shown in FIG.
It has been found that the rubber can resist the stress level of the filler acting by the wheel load F1.

In FIG. 13C, a line L56 represents the degree of adhesion stress at the upper end 2b of the interface 2a between the precast floor slab and the filler 25. A line L57 represents the degree of adhesion stress at the lower end 2c of the interface 2a between the precast floor slab and the filler 25.
The line is drawn down to the side of FIG. 13C without changing the position in the bridge axis direction X from the position N4 in FIG. 13A, and the degree of adhesion stress on the vertical axis in FIG. 13C corresponding to the intersection with the line L56. I Read. Thus, it can be seen that the degree of adhesion stress τ34 at the upper end 2b of the interface 2a when the wheel load F1 is applied to the position N4 is about 0.3 N / mm ² .
Similarly, it can be seen that the degree of adhesion stress τ44 at the lower end 2c of the interface 2a when the wheel load F1 is applied to the position N4 is about −0.3 N / mm ² .
From FIG. 13 (c), it was found that the degree of adhesion stress of the interface 2a when the position where the wheel load F1 acts changes in a range of about −0.3 to 0.3 N / mm ² .

In addition, since rubber itself does not adhere to the precast floor slab, the adhesion strength (σg) of rubber is 0 N / mm ² . For this reason, it is necessary to use an epoxy resin having an adhesion strength of 0.3 N / mm ² or more and rubber together.

Thus, the connection part which is a filler is the 1st connection part (equivalent to an epoxy resin) which is contacting the precast slab, and the 1st connection part which is not contacting the precast slab and is contacting the 1st connection part. In the case of being configured with two connecting portions (corresponding to rubber), the relationship such as the magnitude of the elastic modulus of the connecting portion is defined as follows.
The fact that the elastic modulus of the connecting portion is smaller than the elastic modulus of the precast slab corresponds to the fact that each of the elastic modulus of the first connecting portion and the elastic modulus of the second connecting portion is smaller than the elastic modulus of the precast slab.
That the tensile strength of the connection portion is equal to or higher than the tensile strength of the precast floor slab corresponds to that the tensile strength of the first connection portion and the tensile strength of the second connection portion are each equal to or higher than the tensile strength of the precast floor slab.
And that the adhesion strength of the connection part is equal to or higher than the tensile strength of the precast slab, the adhesion strength that the first connection part adheres to the precast slab, and the adhesion strength that the first connection part adheres to the second connection part. Each corresponds to a tensile strength higher than that of the precast slab.
The adhesion strength between the epoxy resin and the rubber is 6.0 N / mm ² .

The material constituting the filler is preferably a curable filler. Specific examples of the cement-based material include normal mortar, resin mortar, fiber-containing mortar, polymer cement, and the like that are curable fillers with time.
Examples of the epoxy material include an epoxy resin, an epoxy resin mortar, and an epoxy resin grout that are thermosetting resins of synthetic resins.
Examples of the acrylic material include an acrylic resin that is a thermoplastic resin of a synthetic resin, an acrylic resin mortar, and the like.
Other examples include natural resin rubber.

(Analysis result 3)
The result of having analyzed about the level | step difference and opening of a precast slab adjacent to the bridge axis direction X is demonstrated using FIG.
FIG. 14 shows the analysis results of the steps of the precast slabs of the example and the comparative example.
What is indicated by a line L61 is an analysis result in the floor slab system 2 of the embodiment shown in FIG. The load F4 is applied to the end portion on the position A1 side of the precast slab shown in the drawing.
As a comparative example, an analysis result of a precast floor slab that is seamlessly continuous in the bridge axis direction X (corresponding to a continuous structure floor slab system) is indicated by a line L62. As a comparative example, an analysis result of a floor slab system having a discontinuous structure is indicated by a line L63.
In the discontinuous structure, a large step having a length D1 occurs between precast slabs adjacent to each other in the bridge axis direction X. There is no step in the continuous structure.
On the other hand, it was found that the step in the slab system 2 of the example can be suppressed to the length D2.

FIG. 15 shows the analysis result of the horizontal displacement between the lower surfaces of the precast slabs of the example and the comparative example.
What is indicated by a line L66 is an analysis result in the floor slab system 2 of the embodiment shown in FIG. What is indicated by a line L67 is an analysis result in the floor slab system 2A of the embodiment shown in FIG.
As a comparative example, an analysis result of a precast floor slab that is seamlessly continuous in the bridge axis direction X is indicated by a line L68. As a comparative example, the analysis result of the floor slab system having a discontinuous structure is indicated by a line L69.
It was found that the horizontal displacement length D4 of the floor slab system 2 and the horizontal displacement length D5 of the floor slab system 2A are approximately the same as the horizontal displacement length D6 of the floor slab system having a discontinuous structure. In the continuous structure, no horizontal displacement occurs.

(Analysis result 4)
The result of having analyzed about the effect by having a convex part and a recessed part formed in the precast floor slab is demonstrated using FIG.
As shown in FIG. 16, a load F <b> 5 was applied to the upper surface 21 c of the floor slab body 21 of the floor slab system 2. Similarly, as shown in FIG. 17, a load F5 was applied to the upper surface 21c of the floor slab body 21 of the floor slab system 2B. The only difference between the two analysis models is whether or not the convex portion 22 and the concave portion 23 are formed.
Table 1 shows the analysis results arranged with reference to the floor slab system 2B in which the convex portions 22 and the concave portions 23 are not formed.

It was found that the step between the precast slabs adjacent to each other in the bridge axis direction X is reduced by about 20% at maximum by forming the convex portions 22 and the concave portions 23. A level | step difference becomes large, so that the elasticity modulus of a filler is small.
The displacement of the precast slab in the bridge axis direction X corresponds to the length of the mesh opening. It has been found that even if the convex portion 22 and the concave portion 23 are formed, the influence on the opening is small.
The stress level in the bridge axis direction X of the precast floor slab indicates the stress level on the lower surface of the precast floor slab. It has been found that even if the convex portion 22 and the concave portion 23 are formed, the influence on the stress level is small.
It was found that the degree of stress in the direction Y perpendicular to the bridge axis of the filler is not significantly affected even if the convex portions 22 and the concave portions 23 are formed.

It was found that the degree of shear stress of the filler is reduced by about 15% at maximum by forming the convex portions 22 and the concave portions 23.
It was found that the degree of adhesion stress at the interface between the precast floor slab and the filler is not significantly affected even if the convex portions 22 and the concave portions 23 are formed.
It has been found that the shear stress degree at the interface between the precast floor slab and the filler is reduced by about 15% at the maximum when the convex portions 22 and the concave portions 23 are formed.
As described above, by forming the convex portion 22 and the concave portion 23 in the precast floor slab of the floor slab system, the level difference between the precast floor slabs is reduced, the degree of shear stress of the filler and the precast floor slab and the filler It was found that the degree of shear stress at the interface was reduced.

Next, the manufacturing method of the road bridge 1 of this embodiment which manufactures (construction and repair) the road bridge 1 comprised as mentioned above is demonstrated.
First, as shown in FIG. 18, the damaged floor slab 130 is cut and removed by a concrete cutter (not shown).
As shown in FIG. 19, a wire W2 of a hoisting machine W1 such as a crane is attached to an unillustrated anchor provided on the precast floor slab 20 or the like. The precast floor slab 20 is carried on the bridge girder 15 by the hoist W <b> 1 and the precast floor slab 20 is installed on the bridge girder 15. At this time, the convex portion 22 and the concave portion 23 of the precast floor slab 20 adjacent to each other in the bridge axis direction X are arranged with a certain gap S as shown in FIG.
A mold form (not shown) is attached so as to cover the side and the lower side of the gap S of the precast floor slab 20. From a nozzle (not shown), a filler before solidification is injected into the mold. When the filler is solidified, the mold is removed from the precast floor slab 20.
In this way, by providing the filler 25 between the precast floor slabs 20 adjacent in the bridge axis direction X, the floor slab system 2 in which the pair of precast floor slabs 20 are integrated can be constructed.
That is, the method for manufacturing the road bridge 1 is a method for manufacturing the road bridge 1 including the floor slab system 2 using the design method of the floor slab system 2 of the present embodiment.

As described above, according to the floor slab system 2 and the design method of the floor slab system 2 of the present embodiment, the tensile strength of the filler 25 is equal to or higher than the tensile strength of the precast floor slab 20, and the adhesion strength of the filler 25. Is greater than the tensile strength of the precast slab 20. For this reason, the filler 25 is less likely to break than the precast floor slab 20, and the interface 2a between the precast floor slab 20 and the filler 25 is less likely to break than the precast floor slab 20.
Since the elastic modulus of the filler 25 is smaller than the elastic modulus of the precast floor slab 20, the bending moment My transmitted between the precast floor slabs 20 is smaller than the bending moment My of the continuous structure slab system. However, since the tensile strength and adhesion strength of the filler 25 are set to be equal to or higher than the tensile strength of the precast slab 20, the bending moment My is transmitted without breaking the filler 25. For this reason, the bending moment My transmitted between the precast floor slabs 20 increases compared to the bending moment My of the floor slab system having a discontinuous structure.

As a result, cracks extending in the bridge axis perpendicular direction Y are less likely to be formed in the precast floor slab 20 as compared to the continuous structure, and a certain amount of bending moment My is transmitted between the pair of precast floor slabs 20. Since a certain amount of bending moment My is transmitted, the thickness of the precast floor slab 20 is suppressed. If cracks extending in the bridge axis perpendicular direction Y are not easily formed on the precast floor slab 20, the fatigue durability of the precast floor slab 20 is improved.
The floor slab system 2 can be configured by providing a filler 25 between a pair of precast floor slabs 20.
Therefore, according to the present floor slab system 2, the floor slab system 2 can be easily configured from the precast floor slab 20, and fatigue durability can be improved while suppressing an increase in the thickness of the precast floor slab 20. Moreover, according to the design method of the present floor slab system 2, fatigue durability can be improved while suppressing an increase in the thickness of the precast floor slab 20.
Since the elastic modulus of the filler 25 is small, the stress degree of the filler 25 can be relaxed while reliably transmitting the bending moment My. In addition, since the tensile strength and adhesion strength of the filler 25 are equal to or higher than the tensile strength of the precast floor slab 20, the filler 25 is not broken. Therefore, a pair of precast floor slab 20 can be integrated reliably.

By forming the convex portion 22 and the concave portion 23 on the precast floor slab 20, the convex portion 22 is arranged in the concave portion 23. When one of the pair of precast slabs 20 is displaced in the thickness direction Z, the convex portion 22 is engaged with the concave portion 23, so that the other is also displaced in the thickness direction Z. For this reason, when one precast floor slab 20 receives a load in the thickness direction Z, a step in the thickness direction Z generated between the two precast floor slabs 20 can be suppressed.
Since the concave portion 23 is formed at an intermediate portion in the thickness direction Z of the side surface 21b, the convex portion 22 is sandwiched by the precast floor slab 20 from both sides in the thickness direction Z. Therefore, the step in the thickness direction Z generated between the two precast slabs 20 can be more effectively suppressed.

Since the convex portion 22 is formed so that the length in the thickness direction Z becomes shorter toward the distal end side, the convex portion 22 is formed in the concave portion 23 by bringing the pair of precast floor slabs 20 closer to the bridge axis direction X. Can be arranged. Therefore, the construction of the floor slab system 2 is facilitated.
Further, according to the road bridge 1 of the present embodiment, the configuration can be facilitated and the fatigue durability can be improved.
According to the method for manufacturing the road bridge 1 of the present embodiment, the road bridge 1 having improved fatigue durability while suppressing an increase in the thickness of the precast slab 20 can be manufactured.

  As mentioned above, although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications, combinations, and deletions within a scope that does not depart from the gist of the present invention. Etc. are also included.

For example, in the embodiment, the configuration of the floor slab system can be variously modified as described below.
As shown in FIGS. 21 and 22, the floor slab system 3A may include a plurality of precast floor slabs. 22 and later-described FIGS. 23, 24, and 25 do not show the bridge girder 15, the pier, and the later-described support 50.
In the floor slab system 3A, the above-mentioned precast floor slab 20D, a plurality of precast floor slabs 20, and a precast floor slab 20C are arranged in the bridge axis direction X. In the floor slab system 3A, a filler 25 is provided between the precast floor slab 20D, the plurality of precast floor slabs 20 and the precast floor slab 20C adjacent to each other in the bridge axis direction X.

Of the precast floor slab 20D, the plurality of the above-mentioned precast floor slabs 20 and the precast floor slab 20C, the convex portion 22 is disposed in the concave portion 23 of the adjacent one in the bridge axis direction X.
The floor slab system 3A is supported by a pair of bridge beams 15. Each bridge girder 15 is supported by a support 50. The support 50 is installed on a pier (not shown).
In this example, concavo-convex shear keys are arranged at all joints connecting the precast slabs.

A floor slab system 3B shown in FIG. 23 includes a precast floor slab 20C disposed at both ends of the bridge axis direction X, and a plurality of precast floor slabs 45 disposed between these precast floor slabs 20C. .
A filler 25 is provided between the pair of precast floor slabs 20C and the plurality of precast floor slabs 45 adjacent to each other in the bridge axis direction X. A connecting member 48 is disposed in the filler 25. The connection member 48 is disposed in the recesses 23 and 46.
In this example, three-piece type shear keys are arranged at all joints connecting the precast slabs.

The floor slab system 3C shown in FIG. 24 includes a precast floor slab 20C disposed at both ends in the bridge axis direction X, the plurality of precast floor slabs 20 disposed between the precast floor slabs 20C, and the precast. A floor slab 45 is provided.
The precast floor slab 45 is disposed adjacent to one of the precast floor slabs 20C, and the concave portion 46 of the precast floor slab 45 and the concave portion 23 of the precast floor slab 20C face each other.
A filler 25 is provided between the pair of precast floor slabs 20 </ b> C, the plurality of precast floor slabs 20, and the precast floor slabs 45 adjacent to each other in the bridge axis direction X.
The connecting member 48 is disposed between one precast floor slab 20C and the precast floor slab 45, and between the other precast floor slab 20C and the precast floor slab 20.
In this example, three-piece type shear keys are arranged only at joints at both ends in the bridge axis direction X of the floor slab system 3C.

A floor slab system 3D shown in FIG. 25 includes a precast floor slab 20C disposed at both ends in the bridge axis direction X, and a precast floor slab 20 and a precast floor slab 45 alternately disposed between these precast floor slabs 20C. And.
A filler 25 is provided between the pair of precast floor slabs 20C, precast floor slabs 20, and precast floor slabs 45 adjacent to each other in the bridge axis direction X.
A connecting member 48 is disposed in the filler 25 between the precast floor slab 20C and the precast floor slab 20, between the precast floor slab 45 and the precast floor slab 20, and between the precast floor slab 45 and the precast floor slab 20C. Has been.
In this example, three-piece type shear keys and concave-convex type shear keys are alternately arranged in the bridge axis direction X.

  In the above embodiment, the bridge structure is the road bridge 1, but the bridge structure may be a railway bridge or the like.

1 road bridge (bridge structure)
2, 2A, 2B, 2C, 3A, 3B, 3C, 3D Floor slab system (Precast floor slab system)
20, 20C, 20D, 35, 40, 45 Precast floor slab 20A First precast floor slab 20B Second precast floor slab 21a, 21b Side surface 22, 36 Convex part 23, 37, 46 Concave part 25 Filler (connecting part)
Z Thickness direction

In order to solve the above problems, the present invention proposes the following means.
The precast floor slab system of the present invention is formed between a pair of precast floor slabs formed in a plate shape and arranged in a direction intersecting the thickness direction, and a pair of the precast floor slabs. A connection portion that is attached to the floor slab and integrates the pair of precast floor slabs by transmitting a bending moment between the pair of precast floor slabs, It is smaller than the elastic modulus of the precast slab and is not less than one tenth of the elastic modulus of the pair of precast slabs, and the tensile strength of the connecting portion is comparable to the tensile strength of the pair of precast slabs , adhesion strength which the connecting portion is attached to the pair of the precast slab, by a tensile strength equivalent to about a pair of the precast slab, a pair of the Pureki Fatigue resistance of the pair of the precast slab than when between the strike slab was connected with the reinforcing bars and between filling material is characterized by improved.

The precast floor slab system design method of the present invention is provided between a pair of precast floor slabs that are formed in a plate shape and arranged side by side in a direction intersecting the thickness direction, and the pair of precast floor slabs. A precast floor slab system comprising a pair of connecting portions attached to the precast floor slab, and a design method of the precast floor slab system that integrates the precast floor slab and the connecting portion, wherein the connecting portions The elastic modulus of the pair of precast floor slabs is smaller than the elastic modulus of the pair of precast floor slabs and set to 1/10 or more of the elastic modulus of the pair of precast floor slabs. set the tensile strength and about equivalent to the plate, the adhesion strength of the connecting portion is attached to the pair of the precast slab, tensile pair of precast slab Set time and approximately equal, in Rukoto to transmit the bending moment between the pair of the precast slab by the connecting portion, if between the pair of the precast slab and connected with the reinforcing bars and between wadding It is characterized by improving the fatigue durability of the pair of precast slabs .

According to the present invention, the tensile strength of the connecting portion is about equal to the tensile strength of the pair of precast slabs, adhesion strength of the connection portion is about equal to the tensile strength of the precast slab, and elastic modulus precast floor Since the elastic modulus is smaller than the elastic modulus of the plate and not less than 1/10 of the elastic modulus of the precast floor slab, the tensile stress is reduced. For this reason, the connection part is less likely to break than the precast floor slab, and the interface between the precast floor slab and the connection part is less likely to break than the precast floor slab.
The tensile strength and adhesion strength of the connecting portion because it is set to about equal to the tensile strength of the precast slab, connecting portions for transmitting the bending moment without breaking. For this reason, the bending moment transmitted between the pair of precast slabs is increased compared to the bending moment of the floor slab system having a discontinuous structure. As a result, cracks extending in the direction perpendicular to the bridge axis are less likely to be formed in the precast slab compared to the continuous structure, and a certain amount of bending moment is transmitted between the pair of precast slabs. Is suppressed. If cracks extending in the direction perpendicular to the bridge axis are difficult to form on the precast slab, the fatigue durability of the precast slab is improved. When cracks are less likely to be formed, that is, when the floor slab is less likely to be formed into a beam, the effective width of the precast floor slab that can resist the shearing force is increased, so that the punching shear strength is improved.
The floor slab system can be configured by attaching a connecting portion to a pair of precast floor slabs.

Claims (7)

A pair of precast floor slabs formed in a plate shape and arranged side by side in a direction intersecting the thickness direction;
A connecting portion provided between the pair of precast slabs and attached to the pair of precast slabs, and transmitting the bending moment between the pair of precast slabs to integrate the pair of precast slabs When,
With
The elastic modulus of the connecting portion is smaller than the elastic modulus of the pair of precast slabs,
The tensile strength of the connecting portion is equal to or higher than the tensile strength of the pair of precast slabs,
The precast floor slab system is characterized in that the adhesion strength at which the connecting portion adheres to the pair of precast floor slabs is equal to or higher than the tensile strength of the pair of precast floor slabs. On the side surface of the first precast floor slab that forms one of the pair of precast floor slabs, a convex portion that is formed so as to protrude from the side surface of the first precast floor slab is provided,
The side surface of the second precast floor slab constituting the other of the pair of precast floor slabs is formed with a recess that is recessed from the side surface of the second precast floor slab and in which the convex portion is disposed. The precast slab system according to claim 1.   3. The precast slab system according to claim 2, wherein the concave portion is formed in an intermediate portion of the side surface of the second precast slab in the thickness direction.   4. The precast floor according to claim 2, wherein the convex portion is formed so that a length in the thickness direction is shortened toward a tip side in a direction in which the convex portion protrudes. 5. Plate system.   A bridge structure comprising the precast slab system according to claim 1. A pair of precast floor slabs formed in a plate shape and arranged side by side in a direction crossing the thickness direction; and a connecting portion provided between the pair of precast floor slabs and attached to the pair of precast floor slabs A precast floor slab system comprising: a precast floor slab system that integrates the precast floor slab and the connecting portion;
The elastic modulus of the connecting portion is set smaller than the elastic modulus of the pair of precast slabs,
The tensile strength of the connecting portion is set to be equal to or higher than the tensile strength of the pair of precast slabs,
The bonding strength at which the connecting portion adheres to the pair of precast slabs is set to be equal to or higher than the tensile strength of the pair of precast slabs,
A design method for a precast floor slab system, wherein a bending moment is transmitted between the pair of precast floor slabs by the connecting portion.   A method for manufacturing a bridge structure, wherein a bridge structure including the precast floor slab system is manufactured using the method for designing a precast floor slab system according to claim 6.

Images