JP2018040168A - Precast floor slab, compositional structure of steel beam and precast floor slab, and composition method of steel beam and precast floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast floor slab, which enables free PC steel layout planning and can prevent immersion from a box out part and resists against shear force generated at the box out part, a compositional structure of the precast floor slab with a steel beam, and a composition method thereof.SOLUTION: A precast floor slab according to this invention is installed on a steel beam and has a steel beam installation part on a part of the slab. The steel beam installation part is formed at a position facing the steel beam top face along a steel beam direction, and has a box out part with a hollow cross section, which includes a storage part, and a loading part with solid cross section, which includes no storage part. The storage part is a space to store stud fixed on the steel beam top face and formed along the steel beam direction so as to have a top plate part on upper side. A shear reinforcement bar, which penetrates the storage part in a direction perpendicular to the steel beam and exposes in the storage part, is buried in the precast floor slab.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a technique related to a precast floor slab installed on a steel girder, and more specifically, a precast floor slab suitable for synthesis with a steel girder and a steel girder using the precast floor slab. This is a technique related to a structure and a synthesis method.

In recent years, replacement work of RC (Reinforced Concrete) floor slabs of steel girder bridges has been performed. This is because the RC floor slabs are significantly deteriorated as a result of repeated repeated loads due to the passing of vehicles over the years, or salt damage caused by the effects of anti-freezing agents, etc., as well as neutralization of concrete and alkali aggregate reaction. The main reason was the phenomenon. As a floor slab that replaces the RC floor slab, it is lightweight, has excellent long-term durability, can be shortened on site construction, and has recently been of high quality such as the use of high-strength concrete (σ = 50 N / mm ² ). From the viewpoint, a precast floor slab is preferably used. Here, “precast” means that products and parts are manufactured in advance in a place different from the site, such as a factory or a manufacturing yard. The concrete slab produced by this precast is called “precast concrete slab”. Although it is sometimes called, here it is simply referred to as “precast floor slab” for convenience.

  When a precast floor slab is installed on an existing steel girder, a composite girder in which the steel girder and the precast floor slab are integrated, and a non-synthetic girder in which the steel girder and the precast floor slab are not integrated are conceivable. Non-synthetic girders behave differently because the steel girders and precast slabs are independent of each other. Therefore, even if the load is the same, the precast slabs will bend more greatly than the synthetic girders. For this reason, in cases where the composite slab is replaced with a non-synthetic girder and the floor slab is replaced, measures for reinforcement against deflection and stress of the steel girder are generally taken.

  On the other hand, the composite girder has a relatively large rigidity because the steel girder and the precast slab work together, and has a smaller deflection than the non-synthetic girder. It is known that when the floor slab is replaced, it is not necessary to reinforce the steel girder, or the amount of reinforcement of the steel girder is considerably reduced as compared with the case of replacing the non-synthetic girder. In order to form a composite girder using steel girders and precast slabs, a technique using studs including headed studs is the mainstream. Specifically, a headed stud is welded to the upper surface of the steel girder (that is, the upper part of the upper flange), this headed stud is placed in a box opening provided in a precast floor slab, and a non-shrink mortar is placed in the box opening. Steel girders and precast slabs are integrated by injecting and solidifying fillers such as high-fluidity concrete.

  Usually, a considerable number of studs are required to integrate the steel girder and the precast slab. Therefore, many box opening parts must be provided in the part (namely, part located above a stud) facing a steel girder upper surface among precast slabs. On the other hand, PC (Pressed Concrete) steel for introducing prestress in a direction orthogonal to the steel girder direction (hereinafter referred to as “steel girder orthogonal direction”) is often embedded in the precast slab.

  FIG. 9 is a schematic view showing a composite structure of a conventional steel girder and a precast slab, in which (a) is a transverse sectional view, (b) is a plan view thereof, and (c) is a longitudinal sectional view thereof. As shown in this figure, a headed stud S is welded and fixed to the upper flange surface of the steel girder G (main girder), and the headed stud S is mounted when the precast floor slab B is installed on the steel girder G. The precast floor slab B is provided with a box opening E so that it can be accommodated. As shown in FIG. 9C, a large number of headed studs S are arranged side by side in the steel girder direction (bridge axis direction), so as shown in FIG. Requires a plurality of (four places in the figure) box opening portions E. Therefore, the PC steel P for introducing prestress in the direction orthogonal to the steel girder is buried with the gap between the box opening E and the box opening E as shown in FIGS. 9B and 9C. Must. That is, in the conventional composite structure of steel girders and precast slabs, free design is limited in the arrangement plan of the PC steel material P (in addition to the installation position, the number of installations, the diameter of the steel material, etc.).

  Therefore, in Patent Document 1, for the purpose of reducing the number of boxing holes, two types of boxing portions of “through slip prevention” that penetrates the floor slab and “slip prevention cotter” that does not penetrate the floor slab are provided. A composite structure of steel girders and precast slabs is proposed.

JP2015-229818A

  Although the technique proposed in Patent Document 1 does not allow PC steel to be installed at the “through slip prevention” position, PC steel can be installed on the upper part of the “non-slip cotter”. Can be arranged.

  By the way, since the conventional box opening part including the “penetration slip prevention” shown in Patent Document 1 penetrates the floor slab, there is a problem that rainwater or the like is submerged through the box opening part after use. Even if the boxed portion is sufficiently filled with non-shrink mortar, a slight gap still occurs, and water is generated from there. This flooding can cause corrosion in steel girders and headed studs, which in turn can cause significant structural damage.

  Further, another problem can be pointed out in the conventional steel girder and precast slab composite structure including Patent Document 1. As described above, in order to integrate the steel girder and the precast floor slab, a large number of studs are installed, but the shearing force is concentrated at the places where the studs are concentrated. In other words, a large shearing force is generated in the filler (after curing) such as non-shrink mortar, and in some cases, shear cracks occur in this filler, which may cause the composite structure of the steel girder and precast slab to stop functioning. It is done.

  The object of the present invention is to solve the conventional problem, that is, it is possible to arrange PC steel materials freely such as dispersed arrangement, and further prevent water from entering from the box-opening portion, and also occur in the box-opening portion. To provide a composite structure of a precast slab capable of resisting a shearing force and a steel girder using the precast slab, and a synthesis method.

  The present invention was made based on an unprecedented idea of providing a housing portion (a space for housing a stud) that does not penetrate the floor slab and installing a shear reinforcement bar that is exposed in the housing portion. is there.

The precast slab of the present invention is installed on a steel girder, and a steel girder installation part is formed in a part thereof. The steel girder installation part is formed along the steel girder direction at a position facing the upper surface of the steel girder and has a hollow cross-section "boxing part" including the accommodation part and a solid section "mounting part not including the accommodation part" Part ". This accommodating portion is a space for accommodating a stud fixed to the upper surface of the steel girder, and is formed so as to leave the top plate portion above, and is formed along the direction of the steel girder. Further, in the precast floor slab of the present invention, a “shear reinforcement” that pierces the accommodating portion in the direction orthogonal to the steel beam and is exposed in the accommodating portion is embedded.
Moreover, the precast floor slab of this invention can also be formed with the steel girder installation part which consists only of a box opening part.

  The precast floor slab of the present invention may be one in which a plurality of tendons are embedded in the steel girder orthogonal direction. In this case, a multi-stage tension material is embedded in the mounting portion rather than the number of stages of the tension material embedded in the top plate portion.

  The precast floor slab of the present invention may be provided with a through hole penetrating the top plate portion in the thickness direction.

The composite structure of the steel girder and the precast slab of the present invention is a synthetic structure consisting of a steel girder and a precast slab in which a steel girder installation portion is formed. The steel girder installation part is formed along the direction of the steel girder and has a hollow section with a hollow section including the accommodating part and a solid mounting part with a solid section not including the accommodating part. In addition, the accommodating portion is formed so as to leave the top plate portion above, and is formed along the steel beam direction. Furthermore, a “shear reinforcing bar” is embedded in the precast floor slab so as to penetrate the accommodating portion in the direction perpendicular to the steel beam and to be exposed in the accommodating portion. A plurality of studs lined up in the steel girder direction are fixed to the steel girder upper surface within the range where the housing part is arranged and avoiding the shear reinforcement, and the precast floor slab is installed on the steel girder. The accommodating portion accommodates the stud. And by solidifying the inside of the accommodating part including the stud and the shear reinforcement bar with the filler, the steel girder and the precast slab are integrated, and the shear reinforcement bar resists the shearing force generated between the steel girder and the precast slab. .
Moreover, the composite structure of the steel girder and the precast floor slab of the present invention may be a synthetic structure of a steel girder and a precast floor slab in which a steel girder installation portion consisting only of a box opening portion is formed.

The method for synthesizing a steel girder and a precast slab of the present invention is a method of synthesizing a steel girder and a precast slab in which a steel girder installation part is formed, a stud fixing step, a floor slab installation step, and a filler injection step. It has. The steel girder installation part is formed along the direction of the steel girder and has a hollow section with a hollow section including the accommodating part and a solid mounting part with a solid section not including the accommodating part. In addition, the accommodating portion is formed so as to leave the top plate portion above, and is formed along the steel beam direction. Furthermore, a “shear reinforcing bar” is embedded in the precast floor slab so as to penetrate the accommodating portion in the direction perpendicular to the steel girder and to be exposed in the accommodating portion. In the stud fixing step, a plurality of studs arranged in the steel girder direction are fixed to a position where the housing portion is disposed on the upper surface of the steel girder and avoids the shear reinforcement. In the precast floor slab installation process, the precast floor slab is installed on the steel girder so that the steel girder installation part is placed on the steel girder. In the filling material injection process, the stud and shear reinforcement are contained in the accommodating part. Inject the filler.
Further, the method for synthesizing the steel girder and the precast slab of the present invention may be a method of synthesizing the steel girder and the precast slab in which the steel girder installation portion consisting only of the box opening portion is formed.

The precast slab, the composite structure of the steel girder and the precast slab, and the method of synthesizing the steel girder and the precast slab have the following effects.
(1) Since it was not easy to join the precast floor slab and the steel girder by synthesis, the replacement by the precast floor slab has been performed non-synthetically. As a result, the deflection and stress of the steel girder increased, and a considerable amount of steel girder reinforcement was necessary to bring it into an acceptable value. In contrast, the present invention can significantly reduce the amount of reinforcement.
(2) Since the “mounting part” has a solid cross-section that does not accommodate studs, PC steel can be installed, and the “boxing part” that accommodates studs also installs PC steel on the upper top plate part. be able to. Therefore, the arrangement of the PC steel material can be freely designed without being limited to the stud position.
(3) Since the “box opening portion” that accommodates the stud does not penetrate the floor slab, there is no risk of inundation such as rainwater after use, and corrosion of steel girders and the like due to infiltration can be prevented.
(4) Since the inside of the housing part is solidified by combining the exposed shear reinforcement and the stud, it can resist the shearing force generated between the steel girder and the precast slab, and prevents shear cracks in the housing part. can do.
(5) Since studs can be dispersedly arranged, concentration of shearing force can be avoided.
(6) Since the stud can be fixed on the steel girder after grasping the position of the shear reinforcing bar, even if it is a precast floor slab provided with the shear reinforcing bar, the stud is not hindered on the steel girder. Can be installed.

The perspective view which shows a part of synthetic | combination girder which synthesize | combined the precast floor slab of this invention and the steel girder. (A) is sectional drawing which shows a steel girder installation part typically, (b) is a top view which shows typically the steel girder installation part seen from the downward direction. (A) is sectional drawing which shows a box extraction part typically, (b) is sectional drawing which shows a mounting part typically. The top view which shows typically the steel girder installation part which consists only of a box extraction part. The fragmentary sectional view which shows the shear reinforcement reinforcement embed | buried under the precast floor slab. The fragmentary longitudinal cross-section which shows the synthetic | combination structure which synthesize | combined the precast floor slab in which the steel girder installation part which has a box extraction part and a mounting part was formed, and the steel girder. The fragmentary longitudinal cross-section which shows the synthetic | combination structure which synthesize | combined the precast floor slab of this invention in which the steel girder installation part which has only a boxing part was formed, and the steel girder. The flowchart which shows the flow of the main processes in the method of removing the existing RC floor slab and forming the composite structure of a precast floor slab and a steel girder. (A) is a cross-sectional view showing a composite structure of a conventional steel girder and a precast slab, (b) is a plan view showing a composite structure of a conventional steel girder and a precast slab, and (c) is a conventional steel girder and The longitudinal cross-sectional view which shows the synthetic structure of a precast floor slab.

  An example of the precast floor slab of the present invention, a composite structure of a steel girder and a precast floor slab, and a method of synthesizing a steel girder and a precast floor slab will be described with reference to the drawings.

1. Precast floor slab First, the precast floor slab of the present invention will be described. FIG. 1 shows a composite girder of a bridge, and is a perspective view showing a part of a synthetic girder obtained by synthesizing a precast floor slab 100 and a steel girder 200 of the present invention. In this figure, only one precast floor slab 100 is shown. Of course, as a whole bridge, a plurality of steel girders 200 (in this case, main girders) are arranged in the direction of the bridge axis. The precast floor slab 100 is bridged in a direction perpendicular to the bridge axis, and the precast floor slabs 100 that are bridged in the direction perpendicular to the bridge axis are arranged in the bridge axis direction to form a floor slab of the entire bridge. Here, for convenience, the axial direction of the installed steel girder 200 (that is, the direction of the bridge axis) is referred to as “steel girder direction”, and the direction orthogonal to the direction of the steel girder (that is, the direction perpendicular to the bridge axis) is referred to as “the direction perpendicular to the steel girder” I will call it.

  When the precast floor slab 100 is installed on the steel girder 200 (hereinafter referred to as “installation attitude”), as shown in FIG. 1, an “accommodating portion 111a” is provided on the lower surface side. A “shear reinforcing bar 120” is embedded in the housing portion 111a so as to penetrate in the direction perpendicular to the steel girder and exposed in the housing portion 111a. The accommodating portion 111a is a space that is boxed to accommodate the stud 300 that is fixed to the upper surface (upper flange) of the steel beam 200. The precast floor slab 100 may be prestressed in the direction orthogonal to the steel girder by a PC steel material (hereinafter referred to as “tension material 130”), or may be a non-shrink mortar or the like in the accommodating portion 111a. A “through hole 140” that can also be used for injecting the filler may be provided.

(Steel girder installation)
As described above, the precast floor slab 100 is installed across the steel beam 200. That is, only a part of the precast floor slab 100 is placed on the steel beam 200. The present invention has one technical feature in the “part placed on the steel girder 200”, and here it is referred to as a “steel girder installation part” for convenience. In addition, although the steel girder installation part may be directly mounted on the steel girder 200, it may be indirectly mounted on the steel girder 200 via a height adjustment stand (made of rubber or plastic). is there. In any case, the steel girder installation part is a part that directly receives the reaction force from the steel girder 200, and bears a large shearing force. Therefore, as shown in FIG. It is common. Similarly, the steel girder installation portion of the present invention may be formed in a haunch shape, or may have the same member thickness as the other without being formed in a haunch shape.

  FIGS. 2A and 2B are diagrams schematically showing the steel girder installation portion 110, where FIG. 2A is a cross-sectional view and FIG. 2B is a plan view seen from below. As shown in FIG. 2 (a), the steel girder installation part 110 is formed in the part facing the upper surface of the steel girder 200 in the precast floor slab 100 in the installation posture. Therefore, as can be seen from FIG. 2B, the steel girder installation part 110 is formed over the steel girder direction. Note that one precast floor slab 100 is usually spanned between two or more steel girders 200. FIG. 2 illustrates a case where the precast floor slab 100 is bridged over two steel girders 200, and thus two steel girder installation portions 110 are formed. In this case, the steel girder installation portions 110 may be formed by the number of steel girders 200 (that is, three or more).

  Moreover, the steel girder installation part 110 is formed by the "box removal part 111" and the "mounting part 112" shown in FIG.2 (b). FIG. 3A is a cross-sectional view schematically showing the box opening portion 111, and FIG. 3B is a cross-sectional view schematically showing the placement portion 112. As shown in FIG. 3 (a), the box opening portion 111 is provided with a storage portion 111 a, and when the precast floor slab 100 is installed on the steel girder 200, the stud 300 on the upper surface of the steel girder 200 has the storage portion 111. 111a.

  The accommodating part 111a is formed by boxing a part of the box opening part 111 when the precast floor slab 100 is manufactured. Of course, the housing portion 111a is boxed so that the height of the housing portion 111a is equal to or higher than the height of the stud 300 so that the stud 300 can be housed. However, this boxing does not pass through the precast floor slab 100 (that is, the boxing part 111) but leaves a part of the upper part of the member. Is formed. In other words, the box opening portion 111 has a hollow cross section, and is formed by the top plate portion 111b above the cross section and the accommodating portion 111a below the cross section. As a result of providing the top plate portion 111b above the housing portion 111a as described above, it is possible to prevent inundation after use, and to prevent the steel beam 200 and the stud 300 from being corroded by the inundation.

  One mounting portion 112 is a cross section formed without being boxed when the precast floor slab 100 is manufactured, that is, a cross section in which the accommodating portion 111a is not provided, and the inside of the cross section is as shown in FIG. All are solid sections filled with material (concrete).

  As shown in FIG. 2 (b), the strip-shaped steel girder installation section 110 has box-cutting portions 111 (in the drawing, white portions) and mounting portions 112 (in the drawing, shaded portions) alternately continuous in the steel girder direction. It is formed by arranging. For example, in this figure, a total of three placement portions 112 are provided at both ends and the center, and two box opening portions 111 are provided so as to be sandwiched between the placement portions 112. In addition, many studs 300 may be arrange | positioned in a steel girder direction, and it is good to form the accommodating part 111a as long as possible in the steel girder direction. Therefore, the box opening part 111 is formed in a dimension longer than the mounting part 112 along the steel beam direction. The arrangement and number of the box-cutting portions 111 and the mounting portions 112, and the steel girder direction dimensions of the box-cutting portion 111 can be appropriately designed according to the shape dimensions of the precast floor slab 100, the number of studs 300 to be installed, and the like. it can.

  Further, depending on various conditions such as the size of the precast floor slab 100 and the steel girder 200 or an assumed external force, the precast floor slab 100 of the present invention is a steel girder installation part 110 in which the placement part 112 is not provided, that is, The steel girder installation part 110 which has only the box part 111 can also be formed. In this case, the cross section (box extraction part 111) shown in FIG. 3A is formed across the steel girder direction of the precast floor slab 100, that is, the entire range of the steel girder installation part 110 becomes the box extraction part 111, and therefore shown in FIG. Thus, when the precast floor slab 100 is viewed from below, the plane positions of the steel girder installation part 110 and the box opening part 111 coincide.

(Shear reinforcement)
As described above, the precast floor slab 100 is provided with the shear reinforcement 120 in addition to the main reinforcement and the distribution reinforcement. FIG. 5 is a partial cross-sectional view showing the shear reinforcing bar 120 embedded in the precast floor slab 100. As shown in this figure, the shear reinforcing bar 120 is provided with a fixing portion at the upper part of the precast floor slab 100, bent in an oblique direction therefrom, and further provided with a portion penetrating the accommodating portion 111a in the direction perpendicular to the steel girder. . Accordingly, a part of the shear reinforcing bar 120 is exposed in the housing portion 111a. As the shear reinforcing bar 120, various types of reinforcing bars such as round steel bars can be used in addition to deformed bar steel, and reinforcing bars coated with epoxy resin may be used in consideration of durability. The reinforcing bar diameter of the shear reinforcing bar 120 can be appropriately designed according to the shape and design load of the precast floor slab 100, for example, D16, D19, D22, and the like.

(Tension material)
Usually, prestress is introduced into a precast floor slab used as a bridge slab by a PC steel material. Also in the case of the precast floor slab 100 of the present invention, prestress can be introduced by embedding the tendon 130. Specifically, when the precast floor slab 100 is manufactured, the concrete is placed with the tension material 130 (PC steel material) in a tensioned state embedded therein, and the concrete is hardened in that state, and then the tensioned state. Prestress is introduced by cutting the tendon 130 at the end of the floor slab. The tendon 130 may be installed in the direction perpendicular to the steel girder of the precast floor slab 100 in the installation posture.

  Conventionally, in order to accommodate a stud on a steel girder, it is common to provide a box opening part penetrating in a part thickness direction in a part of a precast floor slab. As a result, the arrangement of the tendon has been extremely limited. On the other hand, the precast floor slab 100 of the present invention has the effect that the top plate portion 111b is provided above the accommodating portion 111a that accommodates the stud 300, and the tension material 130 is embedded above the stud 300 as shown in FIG. That is, without limitation, the tendon 130 can be disposed at any position on the precast floor slab 100. Furthermore, since it can be said that the stud 300 can be arranged without being limited to the arrangement of the tendon 130, the stud 300 can be distributed and the concentration of shearing force can be avoided. In addition, since the mounting part 112 of a solid cross section has a member thickness dimension larger (thick) than the top plate part 111b, the number of the tension members 130 embedded in the mounting part 112 (the number arranged in the vertical direction) is the top plate. It is desirable to increase the number of the tension members 130 embedded in the portion 111b. For example, in the case of FIG. 6, the first-stage tension material 130 is embedded in the top plate portion 111 b, and the two-stage tension material 130 is embedded in the mounting portion 112.

2. Next, the composite structure of the steel girder and the precast slab of the present invention will be described. 6 and 7 are partial longitudinal sectional views showing a synthetic structure in which the precast floor slab 100 described so far and the steel girder 200 are synthesized. 6 shows a case in which a steel girder installation part 110 having a placement part 112 and a box opening part 111 is formed, and FIG. 7 shows a case in which a steel girder installation part 110 having only the box extraction part 111 is formed. Show. As shown in these drawings, a large number of studs 300 arranged in the steel beam direction are fixed to the upper surface (upper flange) of the steel beam 200 by, for example, welding. The steel girder 200 is a steel member and generally uses an I-shaped steel. However, an H-shaped steel can be used according to the scale of the bridge, and a box girder can also be used. The stud 300 fixed to the steel girder 200 is often a headed stud provided with a larger-diameter member on the head than the others, but the reinforcing bars are formed in a mountain shape (triangle shape) or a U-shape (square shape). It is possible to employ studs 300 of various shapes, such as those bent into two or mere upright short reinforcing bars.

  The precast floor slab 100 is installed on the steel beam 200 to which the stud 300 is fixed. At this time, the precast floor slab 100 is installed while adjusting the position so that the planar positions of the stud 300 and the accommodating portion 111a coincide, that is, the stud 300 is accommodated in the accommodating portion 111a. Then, a filler such as non-shrink mortar is injected into the accommodating portion 111a in a state including the stud 300 housed in the accommodating portion 111a and the shear reinforcement 120 exposed to the accommodating portion 111a. By hardening, a composite structure of the precast floor slab 100 and the steel beam 200 is formed. According to this composite structure, not only the precast floor slab 100 and the steel girder 200 are integrated by the stud 300 in the accommodating portion 111a, but also the precast floor slab 100 and the steel girder 200 are formed by the shear reinforcing bar 120 in the accommodating portion 111a. Since it connects, it can resist more with respect to the shear force which arises between the precast floor slab 100 and the steel beam 200 compared with the past.

3. Method of synthesizing steel girder and precast slab Next, we synthesized precast slab 100 and steel girder 200 described in “1. Precast slab” and explained in “2. Composite structure of steel girder and precast slab”. A method for forming the synthesized structure will be described. FIG. 8 is a flowchart showing a main process flow in the method of removing the existing RC floor slab and newly forming a composite structure of the precast floor slab 100 and the steel beam 200.

  First, the existing RC floor slab is removed (Step 11), and the fixing surface of the stud 300 is cleaned (Step 12), such as removing unnecessary materials attached to the upper surface (upper flange) of the steel beam 200. And the position which installs the precast floor slab 100 is measured, and the position is marked on the upper surface of the steel girder 200. At this time, in consideration of the positions of the accommodating portion 111a and the shear reinforcing bar 120, the fixing position of the stud 300 is marked (Step 13). Next, the stud 300 is fixed by welding or the like to the fixing position marked in the previous step on the upper surface of the steel girder 200 (that is, the position of the accommodating portion 111a and avoiding the position of the shear reinforcing bar 120). Go (Step 14). When the stud 300 is fixed, the precast floor slab 100 is installed at a predetermined position on the upper surface of the steel girder 200 (Step 15). In order to adjust the installation height of the precast floor slab 100, it is preferable to use a height adjustment stand made of rubber or plastic or a height adjustment bolt. The height adjusting table is disposed on the steel beam 200 (the placement portion 112 position) before the precast floor slab 100 is installed, and the precast floor slab 100 is installed by adjusting the dimension (height). Adjust the height. The height adjustment bolt is inserted into a female screw provided on the precast floor slab 100. After the precast floor slab 100 is installed, the height of the height adjustment bolt is adjusted to adjust the installation of the precast floor slab 100. Adjust the height. When the precast floor slab 100 can be installed, a soul sponge 400 (FIG. 5) for preventing leakage of the filler is arranged over the entire length of the steel beam 200, and then a filler such as non-shrink mortar is injected into the accommodating portion 111a ( Step 16). At this time, if a through-hole 140 that penetrates the top plate portion 111b in the thickness direction is provided in advance, the filler can be injected using the through-hole 140, and the inside of the accommodating portion 111a can be injected through the through-hole 140. You can also evacuate the air. In addition, it is good to make the through-hole 140 as small as possible so that the inundation after service can be prevented. When the injected filler is hardened, the filler, the stud 300, and the shear reinforcement 120 are solidified integrally in the housing portion 111a. As a result, a composite structure in which the precast floor slab 100 and the steel beam 200 are integrated is formed. Is done.

  The precast slab of the present invention, the composite structure of the steel girder and the precast slab, and the synthetic method of the steel girder and the precast slab can be used for bridges of all uses such as road bridges, railway bridges, river bridges, overpass bridges, It can be used for bridges that cross over various types such as overpasses. Further, the present invention is not limited to the case where the existing bridge is used for floor slab replacement work, but can also be applied to a new bridge. Considering that the present invention can provide safe traffic and thereby extend the life of the bridge, it can be said that the invention can be used not only industrially but can also make a great social contribution.

DESCRIPTION OF SYMBOLS 100 Precast floor slab 110 Steel girder installation part (for precast concrete slab) 111 Box opening part (for steel girder installation part) 111a (For box extraction part) Housing part 111b (For box extraction part) Top plate part 112 (Steel girder installation) Placement part 120 Shear reinforcement (of precast concrete slab) 130 Tension material (of precast concrete slab) 140 Through hole (of precast concrete slab) 200 Steel girder 300 Stud 400 Soul sponge B (Conventional) Precast floor slab E (Conventional) Box opening G Steel girder P PC steel S Headed stud

Claims (8)

In precast floor slabs installed on steel girders,
A steel girder installation part is formed along the steel girder direction at a position facing the upper surface of the steel girder,
The steel girder installation part has a hollow section with a hollow section including a storage part, and a mounting part with a solid cross section not including the storage part,
The accommodating portion is a space for accommodating a stud fixed to the upper surface of the steel girder, and is formed so as to leave a top plate portion above, and is formed along the steel girder direction,
Shear reinforcement bars embedded in the steel girder orthogonal direction, penetrating the housing part and exposed in the housing part,
Precast floor slab characterized by that. A plurality of tendons are buried in the direction perpendicular to the steel girder,
More than the number of steps of the tension material embedded in the top plate portion than the number of steps of the tension material embedded in the mounting portion,
The precast slab according to claim 1, wherein: In precast floor slabs installed on steel girders,
A steel girder installation part is formed along the steel girder direction at a position facing the upper surface of the steel girder,
The steel girder installation part is a hollow cross section consisting of an accommodation part and a top plate part,
The accommodating portion is a space for accommodating a stud fixed to the upper surface of the steel beam, and is formed so as to leave the top plate portion above.
Shear reinforcement bars embedded in the steel girder orthogonal direction, penetrating the housing part and exposed in the housing part,
Precast floor slab characterized by that. The top plate portion is provided with a through hole penetrating the top plate portion in the thickness direction.
The precast slab according to any one of claims 1 to 3, wherein: In the composite structure consisting of steel girders and precast slabs,
The precast floor slab is formed with a steel girder installation portion having a hollow cross-section boxing portion including a housing portion and a solid section mounting portion not including the housing portion along the steel girder direction. The accommodating portion is formed so as to leave the top plate portion above, and is formed along the steel girder direction.
Furthermore, the precast floor slab is embedded with a shear reinforcing bar that penetrates the housing part in the direction perpendicular to the steel girder and is exposed in the housing part,
A plurality of studs lined up in the steel girder direction are fixed in a range where the housing portion is arranged in the steel girder upper surface and avoiding the shear reinforcement bars,
The accommodating portion of the precast floor slab installed on the steel girder accommodates the stud, and the inside of the accommodating portion including the stud and the shear reinforcing bar is solidified with a filler, whereby the steel girder and the precast The floor slab is integrated,
The shear reinforcement may resist shear forces generated between the steel girders and the precast slab,
A composite structure of steel girders and precast slabs. In the composite structure consisting of steel girders and precast slabs,
The precast floor slab is formed with a steel girder installation portion having a hollow cross section composed of a housing portion and a top plate portion along the steel girder direction, and the housing portion is formed so as to leave the top plate portion above. ,
Furthermore, the precast floor slab is embedded with a shear reinforcing bar that penetrates the housing part in the direction perpendicular to the steel girder and is exposed in the housing part,
A plurality of studs lined up in the steel girder direction are fixed in a range where the housing portion is arranged in the steel girder upper surface and avoiding the shear reinforcement bars,
The accommodating portion of the precast floor slab installed on the steel girder accommodates the stud, and the inside of the accommodating portion including the stud and the shear reinforcing bar is solidified with a filler, whereby the steel girder and the precast The floor slab is integrated,
The shear reinforcement may resist shear forces generated between the steel girders and the precast slab,
A composite structure of steel girders and precast slabs. In the method of synthesizing steel girders and precast slabs,
The precast floor slab is formed with a steel girder installation portion having a hollow cross-section boxing portion including a housing portion and a solid section mounting portion not including the housing portion along the steel girder direction. The accommodating portion is formed so as to leave the top plate portion above, and is formed along the steel girder direction.
Furthermore, the precast floor slab is embedded with a shear reinforcing bar that penetrates the housing part in the direction perpendicular to the steel girder and is exposed in the housing part,
Stud fixing step of fixing a plurality of studs arranged in the steel girder direction at a position where the housing portion is arranged in the steel girder upper surface and avoiding the shear reinforcement,
A precast floor slab installation step of installing the precast floor slab on the steel girder so that the steel girder installation part is disposed on the steel girder;
A filler injecting step of injecting a filler into the accommodating part including the stud and the shear reinforcement contained in the accommodating part;
A method of synthesizing a steel girder and a precast slab characterized by comprising: In the method of synthesizing steel girders and precast slabs,
The precast floor slab is formed with a steel girder installation portion having a hollow cross section composed of a housing portion and a top plate portion along the steel girder direction, and the housing portion is formed so as to leave the top plate portion above. ,
Furthermore, the precast floor slab is embedded with a shear reinforcing bar that penetrates the housing part in the direction perpendicular to the steel girder and is exposed in the housing part,
Stud fixing step of fixing a plurality of studs arranged in the steel girder direction at a position where the housing portion is arranged in the steel girder upper surface and avoiding the shear reinforcement,
A precast floor slab installation step of installing the precast floor slab on the steel girder so that the steel girder installation part is disposed on the steel girder;
A filler injecting step of injecting a filler into the accommodating part including the stud and the shear reinforcement contained in the accommodating part;
A method of synthesizing a steel girder and a precast slab characterized by comprising:

Images