Road structure and construction method for road structure

Abstract

To provide a simple road structure with a space under a road surface, having good space utilization efficiency.SOLUTION: A road structure 10 includes: mutually opposed side walls 28 formed by steel sheet piles 18 arranged in two rows in a ground 16; a road surface floor 12 including precast concrete slabs 24 suspended between the mutually opposed side walls 28 and joined at both ends with sheet piles; and concrete underground slabs 22 formed on a bottom surface of an underground space 20 formed by digging between the mutually opposed side walls 28.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a road structure, and more particularly to a road structure having a space below the road surface and a construction method thereof. [Background technology]

[0002] A road structure in which a space is formed below the road surface is known. The following Patent Document 1 discloses a road structure in which piles (3) are erected in a grid pattern on a road body (2) dug from the ground surface, precast concrete slabs (1) are placed and fixed on the piles (3), and a space (14) is formed below the precast concrete slabs (1).

[0003] Patent Document 2 below discloses a bridge in which H-shaped steel beams (74) are erected on steel pipe sheet piles (90) arranged in two rows, and concrete (84) is poured on the H-shaped steel beams (74). Below the concrete beams (84) is a space where a river flows.

[0004] The reference numerals in the parentheses above are the reference numerals used in the relevant patent documents listed below, and are not related to the reference numerals used in the description of the embodiments of the present application. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-76307 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-23713 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the piles are arranged in a grid pattern, which may interfere with the use of the underground space. In Patent Document 2, the steel pipe sheet pile structure is complex, the side walls are thick, and construction takes time.

[0007] The present invention aims to provide a road structure with a simple configuration that has space below the road surface and that makes good space utilization efficiency, and a construction method for the same. [Means for solving the problem]

[0008] The road structure of the present invention is a road structure comprising two opposing steel sheet piles arranged in two rows in the ground. A side wall in which the surface facing away from the opposing sides of the two rows of sheet piles is in contact with the ground. The structure comprises side walls, a road slab including a precast concrete slab erected between the opposing side walls and rigidly connected to the sheet piles that form the side walls, and a concrete underground floor slab formed on the bottom of a space formed by digging down between the opposing side walls.

[0009] By using the steel sheet piles themselves as the side walls of the underground space, it is possible to install them in a narrow space. Also, by connecting the sheet piles to the precast concrete slabs erected between the side walls, it is possible to offset the force from the ground acting on the opposing sheet piles. Furthermore, by erecting the precast concrete slabs between the side walls, piles between the side walls are no longer necessary.

[0010] In addition, the sheet pile and the precast concrete slab can be joined by inserting anchor bolts embedded in concrete copings that extend along the upper edges of the side walls and are connected to the sheet piles into dowel holes formed in the precast concrete slabs, and filling the dowel holes with filler material.

[0011] In addition, the sheet pile and precast concrete slab are attached to the top of the sheet pile. To the joined support plate The bonded dowels can be inserted into dowel holes formed in the precast concrete slabs, and the dowel holes can be filled with a filler material to form a bonded structure.

[0012] Furthermore, the sheet pile and the underground floor slab can be joined by embedding dowels connected to the sides of the sheet pile into the poured concrete when pouring concrete at least in the area adjacent to the sheet pile to form the underground floor slab.

[0013] Furthermore, the road deck may include a paving deck installed on a precast concrete deck.

[0014] A road structure construction method according to another aspect of the present invention includes a first step of driving steel sheet piles into the ground in two rows, a second step of digging down between the two rows of sheet piles to form a space, a third step of forming a concrete basement floor slab at the bottom of the space, a fourth step of erecting a precast concrete slab on the top ends of the two rows of sheet piles, and a fifth step of rigidly connecting both ends of the precast concrete slab to the two rows of sheet piles. The surfaces of the two rows of sheet piles facing away from each other are maintained in contact with the ground.

[0015] In the above road structure construction method, the fifth step includes forming a concrete coping that extends along the upper edge of the side wall and is connected to the sheet pile, and embedding anchor bolts in the coping during the process of forming the coping, and the anchor bolts can be inserted into dowel holes that have been formed in advance in the precast concrete slab and filled with filler material to connect the sheet pile and the precast concrete slab.

[0016] In the above road structure construction method, the fifth step may include a step of connecting a stud dowel to the upper end of the sheet pile, and in the fifth step, the dowel connected to the upper end of the sheet pile may be inserted into a dowel hole pre-formed in the precast concrete slab, and the dowel hole may be filled with a filler material to connect the sheet pile and the precast concrete slab.

[0017] In the above road structure construction method, the third step includes a step of connecting dowels to the sides of the sheet piles, and in the third step, concrete is poured at least in the area adjacent to the sheet piles so that the dowels connected to the sides of the sheet piles are embedded, thereby connecting the sheet piles to the underground deck.

[0018] The above road structure construction method may include a sixth step of placing a paving slab on the precast concrete slab. [Effects of the Invention]

[0019] By using the steel sheet piles themselves as the side walls of the underground space, it is possible to install the underground space in a narrow space without the need to form separate side walls. In addition, the steel sheet piles themselves are thin, which also helps to install the underground space in a narrow space. Furthermore, by connecting the sheet piles to the precast concrete slabs erected between the side walls, it is possible to prevent the sheet piles from collapsing due to the force from the ground. Furthermore, by erecting the precast concrete slabs between the side walls, piles between the side walls are no longer necessary, which increases the convenience of using the underground space. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view showing a schematic configuration of a road structure according to an embodiment of the present invention; [Figure 2] 1 is a cross-sectional view schematically showing the configuration of a road structure of the present embodiment. [Figure 3] A cross-sectional view showing details of the joint between the sheet pile and the precast plate. [Figure 4] FIG. 10 is a cross-sectional view showing another embodiment of the joint between the sheet pile and the precast slab. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view showing the structure of a road structure 10, with some parts shown in a see-through state. FIG. 2 is a view showing a cross section of the road structure 10 perpendicular to the road extension direction. The road structure 10 includes a road slab 12 exposed at the ground surface and an underground structure 14 formed underground below the road slab 12. The underground structure 14 includes two rows of steel sheet piles 18 driven into the ground 16 and a concrete underground floor slab 22 formed on the bottom of an underground space 20 formed by digging between the two rows of sheet piles 18. The road slab 12 includes a precast concrete slab (hereinafter referred to as "precast slab") 24 installed between the two rows of sheet piles 18 and a pavement slab 26 installed on the precast slab 24. The precast slab is a plate-shaped concrete prefabricated in a shape and size that can be transported from a factory or the like for assembly and installation on site.

[0022] The sheet piles 18 are elongated steel members formed with a predetermined cross-sectional shape. The cross-sectional shape of the sheet piles 18 perpendicular to the longitudinal direction is a curved plate shape, and may be, for example, a shape formed by three sides of an isosceles trapezoid, excluding the longer side of two parallel sides. The sheet piles 18 are driven into the ground 16 with their longitudinal direction aligned vertically, and are then aligned along the roadway to form the side walls 28 of the underground structure 14. By arranging the sheet piles 18 with curved cross-sectional shapes, the side walls 28 are formed into a wave-like shape along the alignment direction. The underground space 20 is formed so that the lower portions of the sheet piles 18 remain in the ground 16, and the underground floor slab 22 is formed on its bottom surface. The underground floor slab 22 may be formed by pouring concrete in place. The underground floor slab 22 may be cast between two rows of sheet piles 18, with both end faces contacting the side surfaces of the sheet piles 18. By interposing the underground floor slab 22 between the sheet piles 18 on both sides, the force that each sheet pile 18 receives from the ground 16 is transmitted to the other sheet pile 18, thereby preventing the sheet piles 18 from collapsing. Alternatively, the underground floor slab 22 may be formed by installing a precast slab on the bottom surface of the underground space 20 at a distance from the sheet piles 18, and pouring concrete between the precast slab and the sheet piles 18.

[0023] To firmly connect the sheet piles 18 and the basement slab 22, stud dowels 30 can be used, for example, welded to the sheet piles 18. Before the basement slab 22 is cast, the stud dowels 30 are welded to the side of the sheet piles 18 at the depth where the basement slab 22 will be formed. These stud dowels 30 are hereinafter referred to as side stud dowels 30. The basement slab 22 is formed by pouring concrete so that the side stud dowels 30 are embedded. A stud dowel is a rod-shaped member with a thick head. When embedded in the concrete, the member to which the stud dowel is joined and the concrete are integrally bonded together. The side stud dowels 30 connect the sheet piles 18 and the basement slab 22. Instead of the stud dowels 30, other shear stop structures, such as reinforcing bar dowels or perforated steel plate dowels, can be used to connect the sheet piles 18 and the basement slab 22.

[0024] FIG. 3 shows details of the connection between the sheet piles 18 and the precast slabs 24. A concrete coping 32 extends along the upper edge of the side walls 28 formed by the sheet piles 18. The coping 32 is provided to surround the upper end of each sheet pile 18 and connects the arranged sheet piles 18 together at their upper ends. Anchor bolts 34 are embedded in the coping 32, and their upper ends protrude upward from the top surface of the coping 32. The precast slabs 24 are placed on the top surface of the coping 32 via an adjustment layer 35. The height of the support surface of the precast slab 24 is adjusted by the thickness of the adjustment layer 35. The precast slabs 24 are long, plate-like members, for example, 2 m wide. Both longitudinal ends of a single precast slab 24 are placed on two rows of sheet piles 18, and the precast slab 24 is installed between the side walls 28. A plurality of precast slabs 24 are arranged, and fiber-reinforced concrete or the like is filled into the joints 37 (see Figure 1) between adjacent precast slabs 24 to integrate the plurality of precast slabs 24. The arranged and integrated precast slabs 24 cover the underground space 20, and roads are constructed on the surface.

[0025] The precast slab 24 is formed with dowel holes 36 for receiving anchor bolts 34. The dowel holes 36 penetrate the precast slab 24 in the thickness direction and preferably have a tapered shape that is wider at the top and narrower at the bottom. When the precast slab 24 is placed on the coping 32, the anchor bolts 34 are inserted into the dowel holes 36. The horizontal cross-sectional shape of the dowel holes 36 may be an elongated hole that is long in the direction of the arrangement of the sheet piles 18, and multiple anchor bolts 34, for example, two, may be inserted into one dowel hole 36. Alternatively, one dowel hole 36 may be formed at each end of one precast slab 24. With the anchor bolts 34 inserted, the dowel holes 36 are filled with a hardening filler material 38, such as high-strength concrete. As the filler material 38 hardens, the sheet piles 18 and the precast slab 24 are bonded together and do not separate. Furthermore, this connection structure rigidly connects the sheet pile 18 and the precast slab 24, which contributes to suppressing bending in the center of the precast slab 24.

[0026] If necessary, a paving slab 26 such as asphalt or concrete road slab may be installed on the surface of the precast slab 24. A waterproof layer or a waterproof and adjustment layer may be provided between the precast slab 24 and the paving slab 26. The top surface of the precast slab 24 may be sloped to allow for drainage of rainwater and the like.

[0027] The construction method of the road structure 10 will be described. First, two rows of sheet piles 18 are driven into the ground 16. An excavation is performed between the two rows of sheet piles 18, exposing the upper portions of the opposing faces of the two rows of sheet piles 18. The exposed portions of the sheet piles 18 become the side walls 28 of the underground space 20.

[0028] Next, side stud dowels 30 are welded to the sheet piles 18 at a depth where the basement floor slab 22 will be installed. Concrete is poured onto the surface of the excavated ground 16 to form the basement floor slab 22. At this time, the side stud dowels 30 are embedded in the poured concrete. As the concrete hardens, the sheet piles 18 and the basement floor slab 22 are joined via the side stud dowels 30. Also, rather than pouring concrete onto the entire surface of the excavated ground 16, the basement floor slab 22 may be formed by placing a precast plate on the ground 16 with a gap between it and the side walls 28 on both sides, and pouring concrete between the precast plate and the side walls 28.

[0029] Next, a coping 32 is constructed along the upper edge of the side wall 28. Specifically, a form is formed at the upper end of the arranged sheet piles 18, and concrete is poured to form the coping 32. At this time, anchor bolts 34 are embedded in the coping 32, and the anchor bolts 34 are integrated with the coping 32.

[0030] Next, the precast slabs 24 are placed on the two rows of sheet piles 18. Specifically, the precast slabs 24 are placed on the copings 32 via an adjustment layer 35. At this time, anchor bolts 34 are inserted into the dowel holes 36 already drilled in the precast slab 24. The dowel holes 36 are filled with filler material 38, which is then allowed to harden. This joins the sheet piles 18 and precast slabs 24 via the copings 32 and anchor bolts 34. The precast slabs 24 are aligned in the direction in which the sheet piles 18 are aligned, i.e., in the direction in which the road extends, and the joints 37 between adjacent precast slabs 24 are filled. Finally, the paving slab 26 is laid on top of the precast slabs 24.

[0031] In the above construction method, the ground 16 between the two rows of sheet piles is excavated, the basement floor slab 22 is formed, and then the precast slab 24 is erected. However, the converse is also possible, where the precast slab 24 is erected, and then the ground 16 is excavated and the basement floor slab 22 is formed.

[0032] Figure 4 shows another embodiment of the connection between the sheet pile 18 and the precast slab 24. Components similar to those described above are assigned the same reference numerals and will not be described again. A support plate 40 is horizontally joined (e.g., welded) to the top end of the sheet pile 18 driven into the ground 16. Furthermore, stud dowels 42 are welded to the top surface of the support plate 40 along the longitudinal direction of the sheet pile 18. To distinguish them from the side stud dowels 30 described above, the stud dowels 42 will hereinafter be referred to as upper stud dowels 42. Furthermore, mortar is poured onto the top surface of the support plate 40 to form an adjustment layer 44, on which the precast slab 24 is placed. The height of the surface on which the precast slab 24 rests is adjusted by adjusting the thickness of the adjustment layer 44.

[0033] The precast slab 24 has dowel holes 36 formed therein to receive upper stud dowels 42. The dowel holes 36 penetrate the precast slab 24 in the thickness direction and preferably have a tapered shape, wider at the top and narrower at the bottom. When the precast slab 24 is placed on the support plate 40, the upper stud dowels 42 are inserted into the dowel holes 36. The dowel holes 36, with the upper stud dowels 42 inserted, are filled with a hardening filler material 38, such as high-strength concrete. As the filler material 38 hardens, the sheet piles 18 and the precast slab 24 are bonded together and do not separate. Instead of the stud dowels described above, other structures, such as rebar dowels or perforated steel plate dowels, can be used to connect the sheet piles 18 and the precast slab 24.

[0034] During the construction process, the support plate 40 is welded horizontally to the upper end of the driven sheet pile 18. An upper stud dowel 42 is welded and erected onto this support plate 40. Mortar is then poured onto the support plate 40 to form an adjustment layer 44, which adjusts the height of the surface on which the precast slab 24 rests.

[0035] A concrete wall may be provided inside or outside the sheet pile 18 so as to be integrated with it. This is expected to improve buckling strength against vertical loads, suppress bending deformation against horizontal loads, and improve watertightness and corrosion resistance.

[0036] By using the sheet piles 18 themselves as the side walls 28 of the underground space 20, an underground space can be created under the road with high spatial efficiency. For example, compared to a construction method in which a box culvert is installed in the ground, a larger underground space can be created by the wall thickness of the box culvert and the gap between the box culvert and the retaining sheet piles. When excavating the ground to bury the box culvert, retaining sheet piles are driven into both sides of the installation space for the box culvert. The box culvert is inserted or constructed between the sheet piles on both sides of the excavated area. At this time, a gap must be provided between the sheet piles and the box culvert. According to the construction method for the road structure 10 of this embodiment, the gap between the sheet piles and the box culvert and the wall thickness of the box culvert can be used as an underground space.

[0037] Furthermore, when constructing a box culvert underground, the concrete pouring for the structure must be carried out in multiple stages, for the bottom slab, side walls, and top slab, and a curing period must be set for each pour. In contrast, the construction method of the above-described embodiment reduces the number of areas that need to be formed by pouring concrete, allowing for a shorter construction period.

[0038] Furthermore, by using the sheet piles 18 as the side walls 28 of the underground space, the amount of concrete used to form the side walls can be reduced, enabling costs to be reduced.

[0039] By connecting the two rows of sheet piles 18 to the basement floor slab 22 via the precast slab 24, the forces acting on the sheet piles 18 from the ground 16 are offset, preventing the sheet piles 18 from collapsing.

[0040] By installing the pavement slabs 26 on the road surface, maintenance work can be simplified by simply replacing the pavement slabs 26 when the road surface is damaged. [Explanation of symbols]

[0041] 10 Road structure, 12 Road surface slab, 14 Underground structure, 16 Ground, 18 Sheet pile, 20 Underground space, 22 Underground floor slab, 24 Precast concrete slab (precast slab), 26 Pavement slab, 28 Side wall, 30 Side stud dowel, 32 Coping, 34 Anchor bolt, 35, 44 Adjustment layer, 36 Dowel hole, 37 Joint, 38 Filler, 40 Support plate, 42 Top stud dowel.

Claims

1. Two opposing side walls formed by sheet piles made of steel plates arranged in two rows in the ground; a road slab including a precast concrete slab installed between the opposing side walls and connected to the sheet piles at both ends; a concrete basement floor slab formed on the bottom of a space formed by digging between the opposing side walls; Equipped with a concrete coping is formed on the upper edge of the side wall, extending along the upper edge and connecting with the sheet pile; An anchor bolt is embedded in the coping, The precast concrete slab has dowel holes formed therein, The dowel holes into which the anchor bolts have been inserted are filled with a filler material to join the sheet piles and the precast concrete slab. road structure.

2. Two opposing side walls formed by sheet piles made of steel plates arranged in two rows in the ground; a road slab including a precast concrete slab installed between the opposing side walls and connected to the sheet piles at both ends; a concrete basement floor slab formed on the bottom of a space formed by digging between the opposing side walls; Equipped with A support plate is joined to the upper end of the sheet pile, and an upper dowel is further joined to the support plate, dowel holes are formed in the precast concrete slab, The dowel holes into which the upper dowels have been inserted are filled with a filler material, thereby joining the sheet piles and the precast concrete slabs. road structure.

3. 3. The road structure according to claim 1 or 2, Side dowels are connected to the sides of the sheet pile, The basement floor slab is formed by pouring concrete at least in a portion adjacent to the sheet pile, and the side dowels are embedded in the poured concrete to connect the sheet pile and the basement floor slab. road structure.

4. 4. The road structure according to claim 1, wherein the road surface slab comprises a paving slab installed on the precast concrete slab.

5. The first step is to drive two rows of steel sheet piles into the ground; a second step of digging a hole between the two rows of sheet piles to form a space; a third step of forming a concrete basement floor slab on the bottom of the space; a fourth step of erecting a precast concrete slab on the top ends of the two rows of sheet piles; a fifth step of rigidly connecting both ends of the precast concrete slab to the two rows of sheet piles, respectively; and The surfaces of the two rows of sheet piles facing away from each other are maintained in contact with the ground, A portion of the opposing surfaces of the two rows of sheet piles is maintained in a state where it directly faces the space. Construction methods for road structures.

6. The first step is to drive two rows of steel sheet piles into the ground; a second step of digging a hole between the two rows of sheet piles to form a space; a third step of forming a concrete basement floor slab on the bottom of the space; a fourth step of erecting a precast concrete slab on the top ends of the two rows of sheet piles; a fifth step of rigidly connecting both ends of the precast concrete slab to the two rows of sheet piles, respectively; and the fifth step includes a step of forming concrete copings on upper edges of the two rows of sheet piles, the concrete copings extending along the upper edges and being connected to the sheet piles, and a step of embedding anchor bolts in the copings during the process of forming the copings; and in the fifth step, the anchor bolts are inserted into dowel holes formed in advance in the precast concrete slab, and the dowel holes are filled with a filler material to connect the sheet piles to the precast concrete slab. Construction methods for road structures.

7. The first step is to drive two rows of steel sheet piles into the ground; a second step of digging a hole between the two rows of sheet piles to form a space; a third step of forming a concrete basement floor slab on the bottom of the space; a fourth step of erecting a precast concrete slab on the top ends of the two rows of sheet piles; a fifth step of rigidly connecting both ends of the precast concrete slab to the two rows of sheet piles, respectively; and the fifth step includes a step of connecting dowels to the upper ends of the sheet piles, and in the fifth step, the dowels connected to the upper ends of the sheet piles are inserted into dowel holes pre-formed in the precast concrete slab, and the dowel holes are filled with a filler material to connect the sheet piles to the precast concrete slab. Construction methods for road structures.

8. A road structure construction method according to any one of claims 5 to 7, wherein the third step includes a step of connecting dowels to the sides of the sheet piles, and in the third step, concrete is poured at least in the area adjacent to the sheet piles so that the dowels connected to the sides of the sheet piles are embedded, thereby connecting the sheet piles to the underground deck.

9. 9. The road structure construction method according to claim 5, further comprising a sixth step of placing a paving slab on the precast concrete slab.

10. 5. A road structure according to claim 1, wherein a part of the surfaces of the sheet piles arranged in two rows facing the other side directly faces the space.

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