JP6715494B2 - Shed - Google Patents

Description

The present invention relates to a shed for protecting roads and railroad tracks along mountains from rockfalls, landslides, avalanches, and the like.

Conventionally, as disclosed in the second embodiment of Patent Document 1, a plurality of main girders are installed at intervals in the length direction of the road, and a plurality of plates (between the adjacent main girders and covering the upper side of the road ( There was a protective structure such as an avalanche stone in which a precast floor slab was erected, and floor slab cocreate (in-place concrete) was formed on the upper surfaces of multiple plates and main girders. This main girder is embedded with a steel frame having upper and lower flange portions to improve bending and shear stress.

JP, 11-236705, A

In the protective structure of the second embodiment of Patent Document 1, both ends of the plate are held so as to be sandwiched between the upper surface of the main girder and the slab concrete, but the degree of joint between the main girder and the plate is weak, Since the joint between the main girder and the plate is almost free to rotate, when a shock such as a rock fall is applied to the upper surface of the plate, a large bending moment is generated in the plate and a large stress is generated in the plate. Therefore, it has been required to further reduce this stress.

The present invention has been made in view of the above background art, and when subjected to an impact such as a rock fall on the upper surface, it is possible to reduce the stress generated in the precast floor slab, and the construction at the site of the mountainous area is also easy. The purpose is to provide sheds.

The present invention is a shed for protecting a passage provided along a slope on a mountain side, which is arranged above the passage in the width direction of the passage and is installed at a predetermined interval in the length direction of the passage. A plurality of precast beams, a slab layer covering the above passages by installing a plurality of precast slabs between each precast beam, and a cast-in-place concrete layer cast on the upper surface of the slab layer. The precast beam has a concrete beam portion which is a main body, and an anchor bar such as a plurality of anchor bolts having one end protruding from the upper surface of the concrete beam portion, and the precast floor slab in the longitudinal direction. on both ends, the anchor bar wherein the end size of the through hole can through the can is formed by a plurality at intervals in the lateral direction,
The plurality of precast floor slabs are arranged side by side in the width direction of the passage, are supported in a state where predetermined regions of the lower surfaces of both ends in the longitudinal direction are in surface contact with the upper surface of the precast beam, and Each of the one ends is a shed that protrudes to the upper surface side of the precast floor slab through each of the through holes of the corresponding precast floor slab and is fixed to the upper surface of the precast floor slab using a fixing tool.

Further, among the plurality of precast beams, wherein the anchor bar the precast beams supporting each end of the two said precast slab arranged in a longitudinal direction of the passage, which is fixed to the two said precast slab Are provided in a pair along the length direction of the passage, and the one ends of the pair of anchor bars are fixed to each other by a connecting member.

The precast beam has a beam cover plate that covers a lower surface and a side surface of the concrete beam part, and a long member for reinforcing a beam part that is embedded in the concrete beam part, and the beam cover plate has a plurality of members. The covering members are connected in the longitudinal direction and are formed in a U-shaped cross section, and the long member for reinforcing the beam portion is arranged inside the beam portion covering plate in the length direction of the beam portion covering plate. The concrete beam part may be formed by casting concrete inside the beam part covering plate to which the long member for reinforcing the beam part is fixed.

For example, the plurality of covering members are formed in a U-shaped cross section by symmetrically arranging and connecting steel plates each having an L-shaped cross section, and the beam covering plate is formed by the plurality of covering members. Can be formed by connecting the ends in the length direction of the.

The precast floor slab is composed of a substantially rectangular concrete floor slab that is a main body, and a floor slab reinforcing plate that is erected in the concrete floor slab, and is installed on the upper surface of the precast beam. In this state, the floor slab reinforcing plate may be installed between the precast beams.

For example, the upper end of the floor slab reinforcement plate is projected from the upper surface of the concrete floor slab, the plurality of precast floor slabs aligned in the width direction of the passage, the upper end of the floor slab reinforcement plate. Alternatively, the vicinity thereof may be fixed to each other by a connecting member. Further, the upper end of the floor slab reinforcing plate is projected from the upper surface of the concrete floor slab, the plurality of precast slabs aligned in the length direction of the passage, the upper end of the floor slab reinforcing plate. The part or its vicinity may be fixed to each other by a connecting member.

The precast floor slab has a floor slab covering plate that covers the lower surface of the concrete floor slab, and the concrete floor slab is formed using the floor slab covering as a mold. You can

Since the shed of the present invention is configured by combining a precast beam and a precast floor slab having a unique structure with a cast-in-place concrete layer, it is possible to remarkably improve the proof stress performance against impact such as rock fall, landslide, avalanche and the like. In particular, the precast beams and the precast floor slabs are strongly joined together, and the joints are less likely to deform, so the bending moment generated in the precast slabs can be reduced when the precast floor slab is impacted by an impact such as a rock fall. The stress generated in the floor slab is effectively reduced. In addition, construction on site is easy.

It is sectional drawing (a) and front view (b) which show one Embodiment of the shed of this invention. It is the front view (a), the top view (b), and the right side view (c) which show the external appearance of the precast beam used for this embodiment. It is the top view (a) which shows the external appearance of a beam part coating plate, and the top view (b) which shows each external appearance of a 1st, 2nd, and 3rd coating member. It is the A1-A1 sectional view (a) and right side view (b) of the 1st coating member of FIG.3(b). It is the front view (a) which shows the plate for beam part reinforcement provided in the precast beam of FIG. 2, and the reinforcing bar for beam part reinforcement, and the front view (b) which shows an unbonded steel wire. It is an A2-A2 sectional view of the precast beam of FIG. 5, and is the figure (a) which looked through a concrete beam part, and the partial sectional view (b) which shows the internal structure of B3 part. It is a fragmentary sectional view showing a connecting structure of a precast beam and a precast pillar of this embodiment. It is a B1-B1 sectional view (a), B2-B2 sectional view (b) of the precast support|pillar of FIG. It is a fragmentary sectional view (a) and C1-C1 sectional view (b) which show the connection structure of a precast beam and a support wall of this embodiment. It is the front view (a) which shows the external appearance of the precast floor slab used for this embodiment, the top view (b), and the figure (c) which expanded the side surface. It is the front view (a) which looked through the concrete floor slab part of the precast floor slab of FIG. 10, the top view (b), and the figure (c) which expanded the side surface. It is a top view, a right side view, and a front view showing a state where a precast floor slab of this embodiment is laid on a precast beam and connected by a connecting member. It is sectional drawing (a) which looked at the connection structure of the precast beam and precast floor slab in FIG. 12 from the side surface side, and sectional drawing (b) seen from the front side. It is a front view (a) showing a state of receiving an impact load on the floor slab, a moment diagram (b) in the case of a conventional structure, and a moment diagram (c) in the case of this embodiment.

An embodiment of the shed according to the present invention will be described below with reference to the drawings. The shed 10 of this embodiment is installed in a passage T (road, railroad track, etc.) provided along a slope S of a mountain, and protects the passage T from rockfalls, landslides, avalanches, and the like.

As shown in FIG. 1, the shed 10 has a plurality of prismatic precast beams 12, each of which is arranged above the passage T in the width direction of the passage T and has a predetermined interval in the length direction of the passage T. Have been installed. Each precast beam 12 is supported by the upper end of the support wall 14 whose end on the slope S side of the mountain is continuous in the length direction of the passage T, and whose end on the opposite side is individually supported by the upper end of the plurality of precast columns 16. Supported by. Above the precast beam 12, a floor slab layer 20 formed by erection of a plurality of precast floor slabs 18 is formed, and is supported by the precast beam 12 to cover the upper side of the passage T. Further, a cast-in-place concrete layer 22 is cast on the upper surface of the floor board layer 20.

As shown in FIG. 2, the precast beam 12 includes a concrete beam portion 24 that is a main body, a beam portion covering plate 26 having a U-shaped cross section that covers the lower surface and the side surface of the concrete beam portion 24, and a plurality of anchor bars 28, 30. And a plurality of members for reinforcing the beam portion embedded in the concrete beam portion 24, which are manufactured in advance in a factory and transported to a site in a mountain area.

In this embodiment, the beam covering plate 26 connects the first, second and third covering members 32, 34 and 36 in the longitudinal direction as shown in FIGS. 3(a) and 3(b). Is formed by.

As shown in FIG. 4( a ), the first covering member 32 is obtained by arranging steel plates 32 a and 32 b having an L-shaped cross section symmetrically and connecting end portions of the steel plates 32 a and 32 b with a plurality of screws 38. , U-shaped in cross section. Plural studs 40a are erected on the inner side surface of the bottom plate portion, and plural studs 40b are erected on the inner side surfaces of the pair of side plate portions. The studs 40a and 40b may be those that stand and are fixed to the inner side surfaces of the steel plates 32a and 32b. For example, metal bolts can be used, and one end of the bolts can be attached to the inner side surfaces of the steel plates 32a and 32b. It is provided by welding or the like.

A joint plate 42 is attached to the right end of the first covering member 32. As shown in FIG. 4( b ), the joint plate 42 is a horseshoe-shaped flat plate, has a plurality of screw holes 42 a formed inside the outer shape at predetermined intervals, and has an outer peripheral edge end surface. The first covering member 32 is joined along the inner surface of the right end portion by welding or the like. Further, as shown in FIG. 3B, a plurality of through holes 44a are provided at a position near the left end of the bottom plate portion.

The second covering member 34 has substantially the same structure as the first covering member 32, and has an outer shape in which the length of the first covering member 32 is, for example, about 1.8 times. That is, by arranging steel plates 34a and 34b having an L-shaped cross section having a length about 1.8 times that of the steel plates 32a and 32b symmetrically and connecting the ends of the steel plates 34a and 34b with a plurality of screws 38, a U-shaped cross section is obtained. Is formed on. The numbers of the screws 38 and the studs 40a and 40b are set to appropriate numbers according to the lengths of the steel plates 34a and 34b. The joint plates 42 are attached to both the right end portion and the left end portion of the second covering member 34.

The third covering member 36 also has substantially the same structure as the first and second covering members 32 and 34, and has an outer shape in which the length of the first covering member 32 is, for example, about 1.2 times. That is, by arranging steel plates 36a and 36b having an L-shaped cross section having a length about 1.2 times that of the steel plates 32a and 32b symmetrically and connecting the ends of the steel plates 36a and 36b with a plurality of screws 38, a U-shaped cross section is formed. Is formed on. The number of the screws 38 and the studs 40a and 40b is set to an appropriate number according to the length of the steel plates 36a and 36b. The joint plate 42 is attached to the left end of the third covering member 36. Further, a plurality of through holes 44b are provided at a position near the right end of the bottom plate portion.

When connecting the left end portion of the second covering member 34 to the right end portion of the first covering member 32, as shown in FIG. 3A, the right end portion of the first covering member 32 is connected. The joint plate 42 and the joint plate 42 at the left end of the second covering member 34 are brought into contact with each other, and the screws 46 are fixed through the screw holes 42a. When connecting the left side end of another second covering member 34 to the right side end of the second covering member 34, and when connecting the third covering member 36 to the right side end of the second covering member 34. The same applies when connecting the left end of the. In this way, by connecting the relatively short first, second, and third covering members 32, 34, and 36 in the length direction, the long beam portion covering plate 26 is formed.

As shown in FIGS. 5A and 6, the precast beam 12 has a long beam portion reinforcing plate 48 (a long member for reinforcing the beam portion) embedded in a concrete beam portion 24. The beam reinforcing plate 48 is made of a strong metal plate or the like and has a substantially rectangular plate-shaped main body 48a. The plate-shaped main body 48a has a length slightly shorter than the length of the beam-covered plate 26, and a width shorter than the height of the side plate portion of the beam-covered plate 26. The beam cover plate 26 is vertically arranged between the pair of side plate portions so as to be on the lower side. The beam reinforcing plate 48 has an upper end portion 48b and a lower end portion 48c formed in a flange shape, and is formed in an H-shaped vertical sectional shape having a large second moment of area. Further, both inner corners of the flange-shaped upper end 48b are previously filled with mortar 48d.

Further, in the concrete beam portion 24, in the vicinity of the lower end portion 48c of the beam portion reinforcing plate 48 (downward), a plurality of beam portion reinforcing reinforcing bars 50 arranged in the length direction of the beam portion covering plate 26 are embedded. There is. Further, as shown in FIGS. 5B and 6, a plurality of unbonded steel wires 52 arranged in the length direction of the beam cover plate 26 are embedded in the concrete beam portion 24, and each of them is strongly tensioned. In this state, both end portions are fixed to the end surface of the concrete beam portion 24. The beam reinforcing reinforcing bar 50 and the plurality of steel wires 52 are members for further improving the load bearing capacity of the concrete beam 24.

The anchor bars 28 such as anchor bolts are each made of a PC steel rod or the like, and one end thereof projects upward from the upper surface of the concrete beam portion 24 and the other end is embedded in the concrete beam portion 24. As shown in FIGS. 2A and 2B, the anchor bars 28 are arranged at predetermined intervals in the length direction of the precast beam 12, and are provided in two rows in the width direction of the precast beam 12. .. The anchor bar 30 is also made of a PC steel rod or the like, one end thereof projects laterally from the left end surface of the concrete beam portion 24, and the other end is embedded in the concrete beam portion 24. As will be described later in detail, the anchor bar 28 is used when fixing the precast floor slab 18 to the precast beam 12, and the anchor bar 30 is used when fixing the precast beam 12 to the support wall 14.

Further, a plurality of through holes 54a penetrating in the vertical direction are formed in the left end portion of the concrete beam portion 24, and communicate with the through holes 44a of the beam portion covering plate 26. A plurality of through holes 54b penetrating in the vertical direction is also formed in the right end portion of the concrete beam portion 24 and communicates with the through hole 44b of the beam portion covering plate 26. As will be described later in detail, the through hole 54a is used when fixing the precast beam 12 to the support wall 14, and the through hole 54b is used when fixing the precast beam 12 to the precast column 16.

An example of a method of manufacturing the precast beam 12 in the factory will be described. First, the beam cover plate 26 is assembled in the state of FIG. Next, as shown in FIG. 6A, a plurality of beam reinforcing reinforcing bars 50 are put on the upper surface of the bottom plate portion of the beam covering plate 26, and the beam reinforcing plate 48 is carried above the studs 40a. The lower end portion 48c is fixed to the upper end portion of the stud 40a by welding or the like. Then, in order to increase the rigidity of the beam portion covering plate 26, the studs 40b of the opposite side plate portions are fixed to each other by the connecting bars 56a and 56b. The upper studs 40b can be directly connected to each other by using a long connecting bar 56a that passes above the beam reinforcing plate 48. For the middle stud 40b, for example, one stud 40b is connected to one side of the beam reinforcing plate 48 by a short connecting bar 56b, and the other stud 40b is opposite to the beam reinforcing plate 48 by another connecting bar 56b. The structure is such that it is connected to the surface, and the connection can be made indirectly through the beam reinforcing plate 48. The same applies to the lower studs 40b as the middle stud 40b.

Then, a plurality of unbonded steel wires 52 are erected on the side of the beam reinforcing plate 48 in a state where the steel wires 52 are not strongly tensioned. Further, the plurality of anchor bars 28 and 30 are temporarily installed at predetermined positions.

Further, before pouring concrete or the like, a dummy member (not shown) for forming the through holes 54a and 54b is temporarily installed at the positions of the through holes 44a and 44b of the bottom plate portion of the beam covering plate 26, A partition plate (not shown) is arranged at a position slightly inside the left and right ends of the beam cover plate 26 to close the left and right ends of the open beam cover plate 26.

Next, in order to form the concrete beam portion 24 in the beam portion covering plate 26, the mortar 24a which is a mixture of cement, sand, water and the like is added to the beam portion reinforcing bar 50 and the lower end portion 48c of the beam portion reinforcing plate 48. Pour to the position where is filled. Since the mortar 24a has a relatively low viscosity, the mortar 24a can smoothly flow into a narrow gap such as a plurality of beam reinforcing steel bars 50. Then, concrete 24b, which is a mixture of cement, sand, gravel, water, etc., is poured all the way to the upper end of the beam cover plate 26 on the upper surface of the hardened mortar 24a. Although the concrete 24b has a relatively high viscosity, since the inner corners of the upper end 48b of the beam reinforcing plate 48 are filled with the mortar 48d, it is possible to prevent air accumulation in this portion, and Since there is no narrow place where the concrete 24b is hard to flow into, there is no problem. The mortar 24a is preferably non-shrink mortar.

When the concrete 24b is hardened, the dummy member is removed to open the through holes 54a and 54b. Further, the partition plate is also removed, and the ends of the steel wire 52 projecting from the end surface of the concrete 24b blocked by the partition plate are strongly tensioned, and both ends thereof are fixed by the fixing tool 58. Then, as shown in FIG. 6B, the portion of the fixing tool 58 is filled with concrete 24c, whereby the precast beam 12 is completed.

The precast beam 12 has a force (impact such as a falling rock) applied to the upper surface of the concrete beam portion 24 by embedding the beam portion reinforcing plate 48, the beam portion reinforcing reinforcing bar 50, and the steel wire 52 in the concrete beam portion 24. On the other hand, the bending resistance and the shearing resistance can be made very strong. In particular, since the beam-reinforcing reinforcing bar 50 and the steel wire 52 are arranged at a position closer to the lower surface (a position where a tensile force is generated) in the concrete beam portion 24, the effect is further enhanced. Therefore, although the strength of the mortar 24a is inferior to that of the concrete 24b, the load-carrying capacity of the concrete beam portion 24 as a whole is significantly improved, and furthermore, cavities and defects are less likely to occur in the concrete beam portion 24. Also stabilizes.

Further, the side surface and the lower surface of the concrete beam portion 24 are covered with the beam portion covering plate 26, and moreover, the studs 40a and 40b are embedded and fitted in the concrete beam portion 24, and the concrete beam portion 24 and the beam portion covering plate 26 are Are closely attached to each other, the concrete beam portion 24 is restrained by the beam portion covering plate 26 when a load is applied, and the load bearing capacity of the concrete beam portion 24 is further improved.

The connecting bars 56a and 56b are members for preventing the beam covering plate 26 from being deformed when concrete or the like is poured into the beam covering plate 26. Can be set freely. If the beam cover plate 26 alone has sufficient rigidity, the connecting bars 56a and 56b may be omitted.

As shown in FIGS. 7, 8A, and 8B, the precast column 16 includes an inner steel pipe 60 and an outer steel pipe 62 having substantially the same length, a concrete portion 64 formed in a space therebetween, and a concrete portion. It is composed of a plurality of PC steel rods 66 embedded in 64, is manufactured in advance in a factory or the like, and is then transported to a site in a mountain area.

Explaining an example of a method of manufacturing the precast support columns 16 in the factory, first, the inner steel pipe 60 and the outer steel pipe 62 are concentrically arranged, and a plurality of PC steel rods 66 are appropriately provided inside the two steel pipes 60, 62 facing each other. A partition plate (not shown) is arranged at a position slightly inside from one end to close one end of the two steel pipes 60 and 62. At this time, it is preferable that the PC steel rods 66 are arranged so as to be biased to a portion (the portion on the right side in FIG. 8) that is on the valley side when the precast support columns 16 are installed on the site. Further, the partition plate side end of the PC steel rod 66 is inserted into a hole provided in the partition plate so as to slightly project, and the opposite side end is the opening of the two steel pipes 60, 62. A large amount is projected from the end portion.

Next, concrete is poured from the open ends of the two steel pipes 60 and 62. When this is hardened and the concrete portion 64 is formed, the partition plate is removed, and the slightly protruding end of the PC steel rod 66 is fixed by the fixing tool 68, whereby the precast pillar 16 is completed.

When the precast support column 16 receives a strong impact such that the precast support column 16 is deformed by rockfall or the like, a constant impact absorption effect is obtained by the operation of crushing the cavity in the inner steel pipe 60. Moreover, since the PC steel rod 66 is arranged at the position on the valley side of the concrete portion 64 (the position where a tensile force is generated), the effect of reinforcing the concrete portion 64 is large.

When installing the precast pillars 16 and the precast beams 12 on the site, first, the precast pillars 16 are erected on the upper surface of the concrete foundation 70, and the portion on the valley side at the end where the fixing tool 68 is attached is shock-absorbed. The hinge member 72 for fixing is fixed. If the shock absorbing function is not required, a rigid structure that is firmly fixed to the concrete foundation 70 may be used.

Next, the precast beams 12 are installed on the upper ends of the precast columns 16 and the support wall 14. When fixing the precast beam 12 to the upper end of the precast column 16, as shown in FIG. 7, the PC steel rod 66 of the precast column 16 is inserted into the through hole 54 b formed in the precast beam 12, and the upper surface of the precast beam 12 is fixed. The end portion protruding from is strongly tensioned and fixed by the fixing tool 74.

A step 76 is provided at the upper end of the support wall 14 on the valley side, and the other end of the precast beam 12 is fixed to the step 76. An anchor hole 78 is provided in advance on the receiving surface 76a of the step 76, and a through hole 80 penetrating laterally is provided in advance on the standing wall portion 76b on the side of the receiving surface 76a. When fixing the end portion of the precast beam 12 to the step 76, the anchor bar 30 protruding laterally from the end surface of the precast beam 12 is inserted into the through hole 80 of the standing wall portion 76b, and the end protruding from the opposite surface of the standing wall portion 76b. The part is strongly tensioned and fixed with the fixing tool 82. Further, the lower surface of the precast beam 12 is placed on the receiving surface 76a via the rubber support plate 84, the vertical anchor 86 of a predetermined length is inserted into the through hole 54a, and the through hole 54a and the anchor hole 78 are communicated with each other. Position horizontally.

Thus, the precast beams 12 and the precast columns 16 are firmly fixed to each other, but not so strongly to the support wall 14 and the concrete foundation 70. That is, when an impact such as a rock fall is received, the precast beam 12 and the precast column 16 can be displaced so that an appropriate cushioning effect can be obtained.

As shown in FIG. 1, a slab layer 20 covering the upper part of the passage T is provided above the precast beams 12, and the slab layer 20 is formed by using a plurality of precast slabs 18. As shown in FIGS. 10 and 11, the precast floor slab 18 covers the concrete floor slab 88 that is the main body, the floor slab reinforcing plate 90 for reinforcing the same, and the lower surface of the concrete floor slab 88. The floor slab cover plate 92 and the like are manufactured in advance in a factory and transported to a site in a mountain area.

The concrete floor slab 88 has a substantially rectangular outer shape in a plan view, the long sides are set to a length that allows both ends to be installed between the pair of precast beams 12, and the short sides are the length of the precast beams 12. The length is set so as to be arranged well in the depth direction, and the thickness is set to a predetermined value in consideration of strength and the like.

The floor slab reinforcing plate 90 is made of a strong metal plate or the like, has a rectangular plate-shaped main body 90a, and is arranged upright so that the pair of long sides of the plate-shaped main body 90a are the upper side and the lower side. .. The floor slab reinforcing plate 90 has an upper end 90b and a lower end 90c formed in a flange shape, and is formed in an H-shaped vertical cross-sectional shape having a large second moment of area. Therefore, by providing the floor slab reinforcement plate 90, the precast floor slab 18 is mainly subjected to a force (shock, etc.) in a direction perpendicular to the floor surface, a bending resistance force and a shear force in the longitudinal direction of the floor surface. The resistance can be very strong. The length of the floor slab reinforcing plate 90 is slightly shorter than the long side of the concrete floor slab 88, and the height from the lower end 90c to the upper end 90b is higher than the thickness of the concrete floor slab 88. An upper end portion 90b projects from the upper surface of the plate portion 88. The protruding length is such that the upper end portion 90b is located in the cast-in-place concrete layer 22 described later. The reason why the upper end 90b projects from the upper surface of the concrete floor slab 88 will be described later.

The concrete floor slab 88 is provided with two thin portions 88a. The thin portion 88a is provided by denting the lower surface side portion of the portion without the floor slab reinforcing plate 90 along the floor slab reinforcing plate 90 in a groove shape. The thickness of the thin portion 88a is, for example, about 1/4 of the total thickness. Thereby, the volume of the concrete floor slab 88 is reduced, and the weight and cost of the precast floor slab 18 are reduced.

Further, as shown in FIG. 10(a), a pair of through holes 94a penetrating in the vertical direction is formed at the left end in the longitudinal direction of the concrete floor slab 88, and a vertical direction is formed at the right end. A pair of through holes 94b that penetrates is formed. As will be described later in detail, the through holes 94a and 94b are used when fixing the precast floor slab 18 to the precast beam 12.

The floor slab covering plate 92 is an iron plate or the like, and adheres closely to the lower surface of the concrete floor slab 88 to cover the entire lower surface. Further, the inner side surface is firmly joined to the lower end portion 90c of the floor slab reinforcing plate 90 by welding or the like. Further, as shown in FIG. 11B, a through hole 96a communicating with the through hole 94a of the concrete floor slab 88 is formed at the left end in the longitudinal direction, and a through hole 94b is formed at the right end. A pair of through-holes 94a are formed so as to penetrate vertically through the through-holes 96b. The floor slab covering plate 92 may be formed by connecting a plurality of covering members in the lengthwise direction similarly to the beam covering plate 26 described above.

The floor slab cover plate 92 absorbs the impact of rockfalls and the like to improve the proof stress performance of the precast floor slab 18, and also serves to prevent a part of the concrete floor slab 88 from falling off into the passage T. Further, the floor slab covering plate 92 may be used as a formwork for forming the concrete floor slab 88 when the precast floor slab 18 is manufactured in a factory.

When assembling the floor slab layer 20 on site, as shown in FIG. 12, the required number of precast floor slabs 18 are erected on the upper surface of the precast beam 12 to cover above the passage T. When fixing the end of each precast floor slab 18 to the upper surface of the precast beam 12, the anchor bar 28 of the precast beam 12 is inserted through the through holes 94a and 94b formed in the precast floor slab 18, as shown in FIG. The end portion 28 a protruding from the upper surface of the precast floor slab 18 is strongly tensioned and fixed by the fixing tool 96. At this time, as shown in FIG. 13B, the portion where each end of the two precast floor slabs 18 aligned in the length direction of the passage T is fixed to the upper surface of one precast beam 12 has a length of the passage T. is in a state the end portion 28a with each other (the end portion 28a to each other projecting from the through hole 94a through holes 94 b) are fixed to each other by a connecting member 98 adjacent to the direction, it is preferable to fix the fixing member 96.

For example, as shown in FIG. 14A, consider a situation in which a plurality of floor slabs SY are installed on the upper surfaces of a plurality of beams HA and the impact load of rockfall RA is applied to the upper surface of a specific floor slab SY. When the fixing between the floor slab SY and the beam HA is weak like the protective structure of Patent Document 1 above, the joint portion of the beam HA and the floor slab SY has a simple double-ended support beam structure. ), a large bending moment is generated in the floor slab SH that receives an impact load, and a large stress is generated in the floor slab SY.

On the other hand, as in the present embodiment, when the upper surface of the precast beam 12 and the lower surface of the precast floor slab 18 are brought into surface contact and strongly fixed using the anchor bar 28 and the fixing tool 96, the precast beam 12 and the precast Since the joint portion with the floor slab 18 is integrated and has a structure of both ends fixed beams, bending moment is generated in the positive and negative directions in the precast floor slab 18 subjected to the impact load, as shown in the moment diagram of FIG. 14(c). However, the peak value of the bending moment is suppressed. Therefore, the stress generated in the precast floor slab 18 that receives an impact load is reduced. Further, since this impact load is effectively transmitted to the adjacent precast floor slab 12 via the connecting member 98, the stress due to the impact load is dispersed.

Next, in order to integrate the plurality of precast floor slabs 18 aligned in the width direction of the passage T (the length direction of the precast beams 12), the floor slab reinforcement plate 90 protruding from the upper surface of each concrete floor slab 88. The upper ends 90b of the two are fixed to each other by welding a plurality of reinforcing bars 100 that are connecting members. By fixing the reinforcing bars 100 in this manner, the shear resistance between the precast floor slabs 18 arranged in the width direction of the passage T is improved and the impact is dispersed.

Next, in order to integrate the plurality of precast floor slabs 18 aligned in the length direction of the passage T, as shown in FIG. 12, the floor slab reinforcing plate 90 protruding from the upper surface of each concrete floor slab 88 is provided. The upper end portions 90b are fixed to each other by welding a plurality of reinforcing bars 102 that are connecting members. The reinforcing bars 102 improve the shear resistance between the precast floor slabs 18 arranged in the lengthwise direction of the passage T, and, like the connecting member 98, serve to disperse the impact. Further, the plurality of reinforcing bars 100 are fixed to each other by welding the plurality of reinforcing bars 104, which are different connecting members, to each other. The reinforcing bar 104 functions similarly to the reinforcing bar 102.

A cast-in-place concrete layer 22 is provided on the upper surface of the floor slab layer 20. The cast-in-place concrete layer 22 is placed so that the upper end 90b of the floor slab reinforcing plate 90 and the entire reinforcing bars 100, 102, 104 are buried.

By providing the cast-in-place concrete layer 22, the strength of the shed 10 can be improved, and the joint between the laid precast floor slabs 18 can be shielded. Further, since the upper end portion 90b of the floor slab reinforcing plate 90 of the floor slab layer 20 is fitted into the cast-in-place concrete layer 22, the bonding force between the cast-in-place concrete layer 22 and the slab layer 20 is increased. You can be stronger.

As described above, since the shed 10 is configured by combining the precast beam 12 and the precast floor slab 18 having a unique structure and the cast-in-place concrete layer 22, the shed 10 has a significantly high resistance to impact such as rock fall, landslide and avalanche. Can be improved. In particular, since the precast beam 12 and the precast floor slab 18 are strongly joined and the joint portions thereof are not easily deformed, it is possible to reduce the bending moment generated in the precast floor slab 18 when an impact such as a rock fall is received. Therefore, the stress generated in the precast floor slab 18 is effectively reduced. In addition, construction on site is easy.

The shed according to the present invention is not limited to the above embodiment and modification. For example, as shown in FIGS. 13A and 13B, the structure for fixing the precast floor slab 18 to the precast beam 12 is one precast floor slab 18 as shown in FIGS. 13A and 13B. Two anchor bars 28 are provided on the precast beam 12 for one end of the. The number of anchor bar 28 can Yasu increased if necessary, can be modified to suit the number of the through holes 94a of the precast slab 10 accordingly. Further, if the area where the upper surface of the precast beam 12 and the lower surface of the precast floor slab 18 are in surface contact is large, the connecting member 98 may be omitted.

In the precast beam 12, a plurality of covering members are connected in the length direction to form the beam covering plate 26. The size, shape, and number of connecting covering members are the length and thickness of the precast beam. Now, it can be appropriately changed in consideration of the efficiency of the assembling work. Similarly, regarding the number of members (reinforcing beams, reinforcing steel bars, unbonded steel wires, studs, connecting members) for reinforcing concrete beams and beam covering plates, etc., the desired strength can be obtained as a whole. Can be changed freely. Further, the beam cover plate may be omitted if necessary.

In the floor slab, if the desired strength is obtained, the connecting member and the floor slab covering plate can be selectively omitted. Further, when a sufficient bonding force between the cast-in-place concrete layer and the floor slab is obtained, the auxiliary member may be omitted, or the upper portion of the plate may not be projected from the upper surface of the concrete body. On the contrary, when it is desired to improve the strength of the precast floor slab, the concrete floor slab may be made into a rectangular parallelepiped shape to eliminate the thin portion. In addition to the above configuration, a foamed styrene layer for cushioning, a sand layer, etc. may be provided on the upper surface of the cast-in-place concrete layer.

10 Shed 12 Precast Beam 18 Precast Floor Slab 20 Floor Slab Layer 22 Cast-in-Place Concrete Layer 24 Concrete Beam Part 24a Mortar 24b, 24c Concrete 26 Beam Part Cover Plate 28 Anchor Bar 28a Ends 32, 34, 36 First, Second, Third coating member 32a, 32b, 34a, 34b, 36a, 36b Steel plate 40a, 40b Stud 48 Beam portion reinforcing plate (long member for reinforcing beam portion)
48a Plate-shaped main body 48b Upper end portion 48c Lower end portion 48d Mortar 50 Reinforcing bar for beam portion 52 Unbonded steel wires 56a, 56b Connecting bar (connecting member)
88 concrete floor slab 88a thin portion 90 floor slab reinforcing plate 90a plate-like body 90b upper end 90c lower end 92 floor slab covering plates 94a, 94b through hole 96 fixing tool 98 connecting member 100, 102, 104 rebar (connecting Element)
S Mountain slope T Passage

Claims (4)

In the shed that protects the passage provided along the slope on the mountain side,
A plurality of precast beams arranged above the passage in the width direction of the passage and installed at predetermined intervals in the length direction of the passage, and a plurality of precast slabs are installed between the precast beams. A floor slab that covers the passage above, and a cast-in-place concrete layer cast on the upper surface of the floor slab,
The precast beam has a concrete beam portion which is a main body, and a plurality of anchor bars having one end protruding from the upper surface of the concrete beam portion,
Wherein at both ends in the longitudinal direction of the precast slab, the anchor bar wherein the end size of the through hole can through the can is formed by a plurality at intervals in the lateral direction,
The plurality of precast floor slabs are arranged side by side in the width direction of the passage, and predetermined regions of the lower surfaces of both ends in the longitudinal direction are respectively supported in a state of being in surface contact with the upper surface of the precast beam,
Each one end of the anchor bar is projected to the upper surface side of the precast floor slab through each through hole of the corresponding precast floor slab, and each is fixed to the upper surface of the precast floor slab using a fixing tool,
The precast beams supporting the end portions of the two precast floor slabs arranged in the lengthwise direction of the passage have the anchor bars fixed to the two precast floor slabs along the lengthwise direction of the passage. A shed provided in a pair, wherein the one ends of the pair of anchor bars are fixed to each other by a connecting member . The precast floor slab is composed of a substantially rectangular concrete floor slab that is a main body, and a floor slab reinforcing plate arranged in the concrete floor slab in the longitudinal direction, and erected on the upper surface of the precast beam. In the state, the upper end of the floor slab reinforcing plate is projected from the upper surface of the concrete floor slab,
The shed according to claim 1, wherein, in the plurality of precast floor slabs arranged in the length direction of the passage, the upper end portion of the floor plate reinforcing plate or its vicinity is fixed to each other by another connecting member. .. The precast floor slab is composed of the concrete floor slab and a floor slab covering plate made of an iron plate that covers the lower surface of the concrete slab, and the through holes penetrate the concrete slab and the floor slab covering plate. The shed according to claim 2, wherein The shed according to claim 3, wherein the plurality of precast floor slabs arranged in the length direction of the passage are fixed to each other at the upper end portion of the floor plate portion reinforcing plate or in the vicinity thereof.

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