Drainage ditch

Abstract

To provide a drainage ditch equipped with weed suppression structure that can prevent the occurrence of gaps between side walls of a frame body supporting a water-permeable lid such as a grating through which rainwater and the like can pass and flow in, and a pavement layer surrounding an outer peripheral surface of side walls, reliably for a long term with only a simple configuration and without time-consuming advance preparation, even if the pavement layer is thick, to suppress weeds from occurring and growing in the gaps.SOLUTION: A grating support frame 5 has: one or more wedge portions 5c that extend above a base end 5c1 and have their tips 5c2 that protrude into a pavement layer 7 below a road surface 2, to suppress thermal contraction movement of the pavement layer 7 by a reaction force 11 that pushes back the pavement layer 7 with an inner surface 5c3 that faces a direction of the thermal contraction force 9 of the pavement layer 7; and protruding portions 5b that are connected perpendicularly to a side wall portion 5a and have their tips that protrude into the pavement layer 7, to suppress thermal contraction movement of the pavement layer 7 by a friction force 10 between an outer upper surface 5b5 that is outside the base end 5c1 of the wedge portion 5c, and the pavement layer 7.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a drainage channel that is buried under a road surface and has a frame body that supports a water-passing lid that communicates with the drainage channel inside its side wall. More specifically, the present invention relates to a weed control structure that can reliably prevent gaps from occurring between the side walls of a frame that supports a water-permeable lid, such as a grating, through which rainwater and the like can pass and flow, and the pavement layer surrounding the outer surface of the side walls, for a long period of time, with just a simple structure and without time-consuming advance preparation, even if the pavement layer is thick, thereby preventing weeds from occurring in the gaps and growing from there. [Background technology]

[0002] A known technology has been developed for some time now to retrofit weed-control members for blocks installed along the side of roads paved with asphalt or the like to prevent the emergence and growth of weeds by having the members comprise abutting parts fixed to the side of the blocks, an upright part connected perpendicularly to the abutting part, and a protruding part protruding upward from the end of the upright part. The protruding part is inserted into the underside of the pavement layer made of asphalt or the like, thereby preventing misalignment between the road and the blocks due to movement of the pavement layer caused by vibrations from passing vehicles and eliminating gaps that arise from this misalignment (see, for example, Patent Document 1).

[0003] Furthermore, a technology is known in which a compressed elastic body is placed between the side of the block and the surface pavement (pavement layer), and the thermal contraction of the surface pavement due to temperature changes is absorbed by the elastic deformation of the elastic body, eliminating the gap between the surface pavement and the block and preventing the emergence and growth of weeds (see, for example, Patent Document 2).

[0004] In addition, a technology is known that prevents the growth of weeds by providing an inclined portion along the side wall of the frame that supports the grating, thereby guiding the growth of weed leaves, stems, and roots in the opposite direction to their natural growth direction (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-216916 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-171605 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-81457 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the frame supports a water-permeable cover such as a grating at its top and forms a gutter-like space (hereinafter referred to as a "gutter space") below it that directs water that flows through the cover to a drainage channel, the frame becomes taller and is buried deeper, resulting in a thicker pavement layer surrounding the frame. In contrast, the weed control structure described in Patent Document 1 can increase the reaction force pushing back the moving pavement layer by extending the protrusions upward so that they penetrate deeper into the pavement layer, but this is not necessarily sufficient for pavement layers that have become thicker and more massive. For this reason, if the pavement layer is thick and the amount of thermal shrinkage increases due to large temperature changes during long-term use, the reaction force from the protrusions alone may be insufficient to resist the movement of the pavement layer, which could lead to significant movement of the pavement layer and the creation or expansion of gaps.

[0007] While it is possible to increase the number of protrusions to increase the aforementioned reaction force, this would require forming multiple protrusions into small components (weed control members) that are separate from the gutter block. This would require consolidating a complex structure into small components, which would increase the cost of parts, thereby increasing the manufacturing cost of the drainage gutter, and would also reduce rigidity due to the more complex structure.

[0008] Furthermore, the weed suppression structure described in Patent Document 2 appears at first glance to have a simple configuration in which a compressed elastic body is inserted at the interface where gaps are likely to occur, but in reality, the conditions under which gaps occur vary greatly depending on the expected maximum gap size, the thermal contraction characteristics of the pavement layer, etc. For this reason, it is necessary to accurately grasp these factors and then optimize the position and shape of the attachment points where the elastic body is attached, as well as the type and degree of compression of the elastic body itself, which poses the problem of requiring time and effort for advance preparation in order to reliably prevent pavement layer movement.

[0009] Additionally, in the weed suppression structure described in Patent Document 3, a single metal plate is precisely bent to a predetermined inclination angle, and then perforated at the bent position to create an inclined portion. This necessitates the use of complex structural components, which increases the cost of components and leads to increased manufacturing costs for the drainage ditch, as well as reduced rigidity due to the complex structure.

[0010] However, the gaps themselves were not eliminated, and the growth of weeds that had germinated there was simply hindered by the slope mentioned above. As a result, some weeds remained in the gaps for a long period of time until their growth became stunted and their proliferation was suppressed, which created the problem that it could not be said that all weed emergence and growth had been reliably suppressed.

[0011] The present invention was devised in light of the above points, and aims to provide a drainage ditch equipped with a weed-suppressing structure that can reliably prevent gaps from occurring between the side walls of a frame body that supports a water-passing lid such as a grating through which rainwater and the like can pass and flow in, and the pavement layer surrounding the outer surface of this side wall, with just a simple structure and without time-consuming advance preparation, even if the pavement layer is thick, and that can suppress weeds from occurring in these gaps and growing there. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the present invention provides a drainage ditch that is buried under the road surface and has a frame body that supports a water-passing lid inside a side wall that communicates with a drainage channel, and the frame body has one or more wedge sections that extend upward from a base end and have tips that protrude into the pavement layer under the road surface, suppressing thermal contraction movement of the pavement layer by a reaction force that pushes back the pavement layer on the side opposite the direction of movement of the pavement layer, and an overhang section that is connected perpendicularly to the side wall section and has a tip that protrudes into the pavement layer, suppressing thermal contraction movement of the pavement layer by a friction force between the surface outside the base end of the wedge section and the pavement layer.

[0013] Furthermore, when attempting to prevent the pavement layer from moving by having the wedge portion dig into the back surface of the pavement layer, even if the pavement layer is thick, the frame body is connected perpendicularly to the side wall portion, with its tip protruding into the pavement layer, and the frictional force between the surface outside the base end of the wedge portion and the pavement layer prevents the pavement layer from moving due to thermal contraction.This adds the frictional force of the protruding portion to the reaction force from the wedge portion, and provides a sufficient resistance force against the movement of even thicker pavement layers with increased mass.

[0014] This means that if the pavement layer is thick, even if the amount of thermal contraction increases due to large temperature changes during long-term use, the pavement layer will not shift significantly, and the occurrence and expansion of gaps can be reliably prevented. Moreover, because the overhanging part is a basic component of the frame, there is no need to carefully examine various conditions, as is the case when inserting a compressed elastic body, and time-consuming advance preparations can be avoided.

[0015] Furthermore, as mentioned above, the frame body extends upward from the base end, with its tip penetrating into the pavement layer below the road surface, and has one or more wedge portions that suppress the thermal contraction movement of the pavement layer by a reaction force pushing back the pavement layer on the side facing the direction of movement of the pavement layer.Since the wedge portions are a basic component of the frame body, there is no need for parts with complex structures such as those mentioned above.

[0016] This allows the number of wedges to be increased or decreased with a simple structure, allowing for fine adjustment of the resistance caused by the reaction force, thereby more reliably preventing the occurrence and expansion of gaps.

[0017] In the present invention, the base end of the wedge portion is connected to at least one of the side wall portion and the protruding portion.

[0018] In this case, when the base end of the wedge is connected to the side wall, the side of the wedge is positioned at an angle to the direction of movement of the pavement layer, so the cross-sectional area perpendicular to the direction of movement is small and the reaction force from the side of the wedge is small. Conversely, the surface of the overhanging part outside the base end of the wedge is not connected to anything and is positioned parallel to the direction of movement, so the friction force between the surface of the overhanging part and the pavement layer is large.

[0019] On the other hand, when the base end of the wedge is connected to the protruding part, the side of the wedge is arranged perpendicular to the direction of movement, so the cross-sectional area perpendicular to the direction of movement becomes large, and the reaction force by the side of the wedge is large. Conversely, when the base end of the wedge is connected halfway to the surface of the protruding part, the surface area of ​​the protruding part outside the base end becomes smaller than when there is nothing on the surface, and since the protruding part is arranged parallel to the direction of movement, the friction force between the surface of the protruding part and the pavement layer is small.

[0020] In this way, the magnitude of the reaction force and friction force can be freely adjusted simply by changing the attachment position of the base end of the wedge. By simply selecting base end attachment conditions that are appropriate for the surface roughness of the pavement layer and its mechanical properties such as elastic modulus, more sufficient resistance to pavement layer movement can be obtained, and the occurrence and expansion of gaps can be prevented more reliably.

[0021] The present invention also provides a retaining structure in which the cross-sectional area of ​​the wedge increases from the base end to the tip end. Here, the "cross-sectional area" refers to the area of ​​a cross section of the wedge taken along a plane perpendicular to the axial direction from the base end to the tip end.

[0022] In this case, even if the adhesion between the surface of the wedge and the inner surface of the pavement layer is insufficient or the amount of thermal shrinkage increases due to large temperature changes, the base end is thinner than the tip end, so the wedge is less likely to fall out of the pavement layer. This prevents a decrease in reaction force due to misalignment between the wedge and the pavement layer, and more reliably prevents the occurrence and expansion of gaps.

[0023] In addition, the present invention has a latching structure in which the side surface of the wedge portion facing the side wall portion is inclined toward the side wall portion as it moves from the base end side to the tip end side.

[0024] In this case, even if the adhesion between the surface of the wedge and the inner surface of the pavement layer is insufficient or the amount of thermal shrinkage increases due to a large temperature change, the wedge will move relatively as the pavement layer moves, and will sink into the pavement layer from the tip side. This prevents a decrease in reaction force due to misalignment between the wedge and the pavement layer, and more reliably prevents the occurrence and expansion of gaps.

[0025] In the present invention, the wedge portion has an engagement structure including an engagement portion capable of frictionally engaging with the pavement layer on at least a part of the side surface facing the side wall portion.

[0026] In this case, even if the adhesion between the surface of the wedge and the inner surface of the pavement layer is insufficient or the amount of thermal shrinkage increases due to large temperature changes, the wedge is less likely to fall out of the pavement layer because of the unevenness of the side of the wedge. This prevents a decrease in reaction force due to misalignment between the wedge and the pavement layer, and more reliably prevents the occurrence and expansion of gaps. [Effects of the Invention]

[0027] According to the present invention, in a drainage ditch that is buried under the road surface and has a frame body that supports a water-passing lid inside the side wall that communicates with a drainage channel, the occurrence of gaps between the side wall of the frame body that supports the water-passing lid, such as a grating through which rainwater and the like can pass and flow, and the pavement layer surrounding the outer surface of this side wall can be reliably prevented for a long period of time with just a simple structure, without time-consuming advance preparation, even if the pavement layer is thick, and a weed suppression structure that can suppress weeds from occurring in these gaps and growing from there can be provided. [Brief explanation of the drawings]

[0028] [Figure 1] 1(a) is a perspective view showing the overall structure of the drainage ditch, and FIG. 1(b) is a partially enlarged perspective view of FIG. 1(a). [Figure 2] FIG. [Figure 3] 3(a) and 3(b) are cross-sectional views of a drainage ditch equipped with a weed suppression structure according to the present invention, where FIG. 3(a) is a cross-sectional view showing the overall configuration of the drainage ditch, and FIG. 3(b) is an enlarged cross-sectional view of the area around the wedge portion. [Figure 4] These are cross-sectional schematic diagrams of weed suppression structures, where Figure 4(a) is a cross-sectional schematic diagram of a frame body with two wedge portions erected from a protruding portion, and Figure 4(b) is a cross-sectional schematic diagram of a frame body with wedge portions extending diagonally upward outward from a side wall portion. [Figure 5] These are cross-sectional schematic diagrams of weed suppression structures, where Figure 5(a) is a cross-sectional schematic diagram of a wedge portion having a locking structure, Figure 5(b) is a cross-sectional schematic diagram of a wedge portion having a hooking structure, and Figure 5(c) is a cross-sectional schematic diagram of a wedge portion having an engagement structure. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention relating to a drainage groove will be described with reference to the drawings to help understand the present invention. In addition, the direction indicated by arrow F in Figure 1 is the forward F in the longitudinal direction L of the drainage ditch 1 of the present invention, the direction indicated by arrow R is the right R in the width direction W of the drainage ditch 1, and the direction indicated by arrow U is the upward U in the vertical direction H of the drainage ditch 1, and the positions and directions of each component described below are based on these directions.

[0030] First, the overall configuration of a drainage ditch 1 to which the present invention is applied will be described with reference to FIGS.

[0031] This drainage ditch 1 has a groove block 3 buried deep under a road surface 2 such as a paved area used for roads and parking lots, a grating 4 which is a water-permeable cover that allows rainwater and the like from the surface of the road surface 2 to flow into this groove block 3, and a frame body 5 which is a frame body that is buried near the road surface 2 and supports this grating 4.

[0032] Inside the groove block 3, a cylindrical drainage channel 3a is formed in the longitudinal direction L to drain water that flows in from the grating 4, and this drainage channel 3a is directly connected to the river, except for domestic wastewater that is purified and treated at the water reclamation center.

[0033] A slit-shaped water conduit 3b communicating with the drainage channel 3a is provided on the upper part of the groove block 3, and a grating 4 is installed above U to cover the water conduit 3b.

[0034] As a result, the water flowing in from the grating 4 passes through the water conduit 3b and is collected in the drainage channel 3a, and then passes through the drainage channel 3a and is discharged directly into the river.

[0035] The cross-sectional shape of the drainage channel 3a is not limited to the circle shown in Figure 2, but may be any cross-sectional shape that allows the inflowing water to be efficiently drained, such as a U-shape, oval, triangle, square, or diamond.

[0036] The grating 4 also has a plurality of long, steel vertical plates 4a arranged parallel to the longitudinal direction L at a predetermined interval, and a plurality of long, steel horizontal plates 4b arranged at a predetermined interval in the width direction W that intersects with the longitudinal direction L relative to the vertical plates 4a, and these horizontal plates 4b enable the spacing between the vertical plates 4a to be maintained and fixed.

[0037] In this way, the water passage section 4c is formed by arranging multiple vertical plate materials 4a and horizontal plate materials 4b in a grid pattern in plan view and joining them by welding, etc. This water passage section 4c is inserted into a storage frame material 4d that is rectangular in plan view and communicates in the up-down direction H, at approximately the center position in the longitudinal direction L, and then joined to the inner wall of the long side 4d1 of the storage frame material 4d by welding, etc.

[0038] The water passage section 4c is not limited to the lattice shape shown in Figures 1 and 2, but may have any structure that can prevent fallen leaves, debris, etc. from entering the grating 4, such as a structure made of punched metal with many small holes drilled therein.

[0039] A partition plate 4d2 is fixed to both the front F and rear ends of the water passage section 4c, and a bottom plate 4d4 is bridged between the lower edge of this partition plate 4d2 and the lower edge of the inner wall of the short side 4d3 of the storage frame material 4d, forming a fixed recess 4d5 surrounded by the partition plate 4d2, the short side 4d3, the bottom plate 4d4, and the ends of the left and right long sides 4d1.

[0040] As a result, the aforementioned water-passing section 4c is stored and fixed within the storage frame material 4d, and fixing recesses 4d5 are provided at both longitudinal ends of the water-passing section 4c to integrate them, thereby forming a single grating 4.

[0041] Furthermore, a bolt hole 4d6 is drilled at approximately the center of this fixing recess 4d5 when viewed from above, while a screw hole 3d is formed at approximately the center of the convex portion (hereinafter referred to as the "mounting portion") 3c of the groove block 3 where no water channel 3b is provided.

[0042] As a result, the bolt 6 is threaded from above U through the bolt hole 4d6 of the fixing recess 4d5 into the screw hole 3d of the mounting portion 3c and tightened, so that the integrated grating 4 is removably fastened to the upper surface of the groove block 3, and by repeating this in the longitudinal direction L, the gratings 4 are installed in a continuous manner.

[0043] The frame body 5 is also composed of left and right grating support frames 5L and 5R that sandwich and support the left and right side surfaces of the grating 4 from the left and right R in the width direction W.

[0044] Each of the left and right grating support frames 5L and 5R has a long, plate-shaped side wall 5a made of steel that abuts from the outside against the long side 4d1 of the storage frame material 4d of the grating 4, and a long, plate-shaped protruding portion 5b made of steel that extends perpendicularly from the lower end of this side wall 5a. The inner end face of this protruding portion 5b abuts against the outer lower end face of the side wall 5a and is joined by welding or the like to form an L-shaped cross-section of the grating support frames 5L and 5R.

[0045] Of these, the overhanging portion 5b is drilled at a predetermined position in the longitudinal direction L with a bolt hole 5b1, while the groove block 3 is formed near the edge of the water channel 3b with a screw hole 3e.

[0046] This allows the bolt 6 to be inserted from above U through the bolt hole 5b1 into the screw hole 3e formed in the groove block 3, and then tightened, thereby allowing the left and right grating support frames 5L and 5R that make up the frame body 5 to be detachably fastened to the top surface of the groove block 3 via the protruding portion 5b.

[0047] The side wall portion 5a is positioned so that its upper end, together with the inner grating 4, is approximately flush with the outer road surface 2, preventing water from the road surface 2 from being blocked by the side wall portion 5a which is higher than the road surface 2, or the water flow from being partially stagnated by the groove formed by the side wall portion 5a which is lower than the road surface 2, allowing the water to flow efficiently to the grating 4.

[0048] At the same time, since the upper end of the side wall portion 5a is substantially flush with the road surface 2, the outer surface 5a1 of this side wall portion 5a functions as a pavement stopper against the end surface 7a of the pavement layer 7, the surface of which is the road surface 2.

[0049] This makes it possible to freely control the thickness of the pavement layer 7 simply by changing the height of the side wall portion 5a, greatly improving the efficiency of construction when laying pavements on roads, parking lots, etc.

[0050] With the above-described configuration, in the drainage ditch 1 having a frame 5 that is buried under the road surface 2 and supports the grating 4, which is a water-passing cover that communicates with the drainage channel 3a, inside the side wall 5a, as described above, water from the road surface 2 flows up to the grating 4, passes through the water conduit 3b above the groove block 3, is collected in the drainage channel 3a, and is then discharged directly into the river.

[0051] In the frame body 5, a protruding portion 5b is connected to the side wall portion 5a in a perpendicular direction, and the weed suppression structure 8 of the present invention is constituted by these side wall portions 5a and protruding portion 5b.

[0052] The groove blocks 3 are generally manufactured as precast concrete products in a factory, transported to the construction site, and installed in a predetermined position along the longitudinal direction L. However, the material is not limited to concrete and can be any material that meets the required strength, corrosion resistance, and other characteristics, such as plastic or metal. Furthermore, while plated steel, such as hot-dip galvanized steel, is often used for the grating 4 and its frame 5, stainless steel and non-ferrous metals such as aluminum alloys can also be used. Furthermore, the material is not limited to metals and can be any material that meets the required strength, workability, and other characteristics, such as ordinary plastics and carbon fiber reinforced plastics.

[0053] Next, the weed control structure 8 will be described with reference to FIGS.

[0054] As mentioned above, the long steel plate-shaped protrusion 5b is placed on the upper surface 3f of the groove block 3 and fastened in place by bolts 6, so that the lower surface 5b2 of the protrusion 5b is in close contact with the upper surface 3f of the groove block 3 and is not in contact with the pavement layer 7.

[0055] On the other hand, the upper surface 5b3 of the protruding portion 5b is exposed to the inside of the pavement layer 7 laid around the frame body 5 and is in contact with the pavement layer 7. In other words, the tip of the protruding portion 5b protrudes into the pavement layer 7 with its lower surface 5b2 in close contact with the upper surface 3f of the groove block 3.

[0056] Here, we will explain how the shapes of the drainage ditch 1 and the pavement layer 7 change due to changes in temperature, etc. Of the drainage ditch 1's constituent parts, the groove block 3, grating 4, and frame 5, as mentioned above, the groove block 3 is generally made of concrete, while the grating 4 and frame 5 are made of steel. While both materials have roughly the same coefficient of expansion, the pavement layer 7 is generally an asphalt mixture, and its coefficient of expansion is two to three times larger than that of the drainage ditch 1.

[0057] Therefore, compared to the drainage ditch 1, the pavement layer 7 expands significantly in high-temperature environments such as summer, but contracts significantly in low-temperature environments such as winter, resulting in the so-called thermal contraction described above. As a result, in low-temperature environments, the overall volume of the pavement layer 7 decreases, and the pavement layer 7 moves in a direction away from the drainage ditch 1, generating a thermal contraction force 9, which tends to create a gap between the outer surface 5a1 of the side wall portion 5a of the frame body 5 and the end surface 7a of the pavement layer 7.

[0058] As a result of this thermal shrinkage movement of the pavement layer 7, a frictional force 10 is generated on the upper surface 5b3 of the protruding portion 5b, which is in contact with the pavement layer 7 as described above, in a direction that suppresses the thermal shrinkage movement of the pavement layer 7 (the opposite direction to the thermal shrinkage force 9).

[0059] Furthermore, in this embodiment, a long steel wedge portion 5c is erected in the middle of the upper surface 5b3. More specifically, a base end 5c1 of the wedge portion 5c is joined to the upper surface 5b3 by welding or the like, and a tip end 5c2 extends upward from the base end 5c1 to protrude into the pavement layer 7 below the road surface 2, thereby forming the wedge portion 5c.

[0060] For this reason, even on the same upper surface 5b3 of the overhanging portion 5b, the magnitude of the frictional force 10 differs greatly between the inside and outside of the wedge portion 5c. In other words, in the region 5b4 of the upper surface 5b3 from the base end 5c1 of the wedge portion 5c to the side wall portion 5a (hereinafter referred to as the "inner upper surface"), the pavement layer 7 is constrained within the space surrounded by the three members of the side wall portion 5a, the overhanging portion 5b, and the wedge portion 5c, so the thermal contraction movement described above hardly occurs, and no frictional force 10 is generated.

[0061] In contrast, in the region 5b5 of the upper surface 5b3 outside the base end 5c1 of the wedge portion 5c (hereinafter referred to as the "outer upper surface"), the pavement layer 7 can move freely due to thermal contraction with almost no constraint, and the aforementioned friction force 10 occurs between the outer upper surface 5b5 and the pavement layer 7.

[0062] In this way, a protrusion 5b is formed on the frame body 5, which is connected perpendicularly to the side wall portion 5a and has its tip protruding into the pavement layer 7, and which suppresses thermal contraction movement of the pavement layer 7 due to the friction force 10 between the outer upper surface 5b5, which is the surface outside the base end 5c1 of the wedge portion 5c, and the pavement layer 7.

[0063] Furthermore, as mentioned above, the wedge portion 5c, which is made of steel and is a long plate, stands upright from the protruding portion 5b which is fastened and fixed to the groove block 3, so the thermal contraction force 9 received from the pavement layer 7 is significantly different between the inner surface 5c3 facing the side wall portion 5a and the outer surface 5c4 opposite this inner surface 5c3.

[0064] In other words, since the outer surface 5c4 faces the same direction as the thermal contraction force 9, the thermal contraction force 9 does not act on it and no reaction force pushing back the pavement layer 7 is generated, whereas since the inner surface 5c3 faces the direction of the thermal contraction force 9, the thermal contraction force 9 acts on it as is and a large reaction force 11 pushing back the pavement layer 7 is generated.

[0065] In this way, a wedge portion 5c is formed in the frame 5, which extends upward from the base end 5c1, with the tip end 5c2 penetrating into the pavement layer 7 below the road surface 2, and which suppresses the thermal contraction movement of the pavement layer 7 by a reaction force 11 that pushes back the pavement layer 7 on the inner side surface 5c3, which is the side surface that faces the direction of the thermal contraction force 9, which is the movement direction of the pavement layer 7. Note that, as will be described in detail later, by providing multiple wedge portions 5c, it is possible to increase the combined reaction force.

[0066] With the above-described configuration, the frame body 5 can generate a large resistance force that is the reaction force 11 plus the friction force 10, and even if the pavement layer 7 is thick and the amount of thermal shrinkage is large, thermal shrinkage movement can be reliably suppressed.

[0067] That is, in the drainage channel 1, which is buried under the road surface 2 and has a frame 5 that supports a grating 4, which is a water-permeable cover that communicates with the drainage channel 3a, inside a side wall 5a, the frame 5 has one or more wedge portions 5c that extend upward from a base end 5c1, and a tip 5c2 that protrudes into the pavement layer 7 under the road surface 2, and an inner surface 5c3 that is the side surface that faces the direction of the thermal contraction force 9, which is the movement direction of the pavement layer 7, and suppresses the thermal contraction movement of the pavement layer 7 by a reaction force 11 that pushes back the pavement layer 7, and one or more wedge portions 5c that are connected in a perpendicular direction from the side wall 5a, and a tip that protrudes into the pavement layer 7, and a friction force 10 between the pavement layer 7 and an outer upper surface 5b5 that is the surface outside the base end 5c1 of the wedge portion 5c Therefore, when it is attempted to prevent the movement of the pavement layer 7 by inserting the wedge portion 5c into the back surface of the pavement layer 7, even if the pavement layer 7 is thick, the frame body 5 is connected perpendicularly to the side wall portion 5a so that its tip protrudes into the pavement layer 7, and the frictional force 10 between the outer upper surface 5b5 outside the base end 5c1 of the wedge portion 5c and the pavement layer 7 and the protruding portion 5b suppresses the thermal contraction movement of the pavement layer 7. As a result, the frictional force 10 by the protruding portion 5b is added to the reaction force 11 by the wedge portion 5c, and it is possible to obtain a sufficient resistance force against the movement of the pavement layer 7, even if the pavement layer 7 has a large mass due to the thickness.

[0068] As a result, if the pavement layer 7 is thick, even if the amount of thermal contraction increases due to large temperature changes during long-term use, the pavement layer 7 will not move significantly, and the occurrence and expansion of gaps can be reliably prevented. Moreover, because the protruding portion 5b is a basic component of the frame body 5, there is no need to carefully examine various conditions, as is the case when inserting a compressed elastic body, and time-consuming advance preparations can be avoided.

[0069] Furthermore, the frame body 5 extends upward U from the base end 5c1, with its tip penetrating into the pavement layer 7 below the road surface 2, and has one or more wedge portions 5c that suppress the thermal contraction movement of the pavement layer 7 by a reaction force 11 that pushes back the pavement layer 7 on the inner surface 5c3 that faces the direction of the thermal contraction force 9 of the pavement layer 7.Since the wedge portions 5c are a basic component of the frame body 5, there is no need for parts with complex structures such as those described above.

[0070] This allows the number of wedge portions 5c to be increased or decreased with a simple structure, making it possible to finely adjust the resistance force of the reaction force 11, and more reliably preventing the occurrence and expansion of gaps.

[0071] Next, various forms of the above-mentioned weed control structure 8, particularly the wedge portion 5c, will be explained using Figures 3 to 5. Note that the figures mainly focus on newly changed or added symbols, and symbols for basic elements will be omitted. Furthermore, since the structure of the grating support frame is symmetrical and substantially identical on both sides, only the right grating support frame of each frame will be explained, and the left grating support frame will be omitted.

[0072] [Alternative form 1] First, a weed control structure 8a of modified embodiment 1, which is provided with a plurality of wedge portions, will be described with reference to FIG. 4(a).

[0073] In this weed control structure 8a, right grating support frame 15R of frame body 15 has multiple wedges 15c1-15c2 provided in order from closest to side wall 15a on top surface 15b1 of overhanging portion 15b, which is a basic structural part of a certain size. As a result, reaction force 16 is generated by the inner surface 15c3 of inner wedge portion 15c1 pushing back pavement layer 7, and reaction force 17 is generated by the inner surface 15c5 of outer wedge portion 15c2 pushing back pavement layer 7.

[0074] Here, even in this embodiment, in the region of the upper surface 15b1 from the base end 15c9 of the outermost outer wedge portion 15c2 to the side wall portion 15a, the pavement layer 7 is constrained within a space surrounded by four members: the side wall portion 15a, the protruding portion 15b, the inner wedge portion 15c1, and the outer wedge portion 15c2, so there is almost no thermal contraction movement and no frictional force is generated. However, in the outer upper surface 15b2 outside the base end 15c9 of the outer wedge portion 15c2, the pavement layer 7 can move freely due to thermal contraction with almost no constraint, so a frictional force 18 is generated between the outer upper surface 15b2 and the pavement layer 7.

[0075] As a result, in this embodiment, the thermal contraction force 9 of the paving layer 7 is supported by two members, the inner wedge portion 15c1 and the outer wedge portion 15c2, in addition to the protruding portion 15b, and the thermal contraction force 9 acting on each wedge portion is reduced compared to when the wedge portion is a single member, and the required rigidity for each wedge portion is smaller, which reduces component costs by making the components lighter and smaller, and improves the ease of assembly of the frame body 15.

[0076] In particular, in this embodiment, by setting upper end 15c4 of inner wedge portion 15c1 lower than upper end 15c6 of outer wedge portion 15c2, heat contraction force 9 acts on the entire inner surface 15c3 of inner wedge portion 15c1. On the other hand, in outer wedge portion 15c2, heat contraction force 9 acts on region 15c7 of inner surface 15c5 that is higher than upper end 15c4 of inner wedge portion 15c1, i.e., the region that does not overlap with inner wedge portion 15c1 when viewed from side wall portion 15a. This provides an arrangement in which multiple wedges 15c1 and 15c2 have inner surface 15c3 and region 15c7 as the surface that directly faces heat contraction force 9.

[0077] This allows the reaction forces generated by both wedge portions to be set more accurately than when the upper ends of the wedge portions are set at the same height and only the wedge portion closest to the side wall portion 15a directly faces the thermal contraction force 9.

[0078] This allows the position and size of each wedge to be changed, allowing the generated reaction force to be set to various values ​​with high precision, making it possible to more reliably prevent the occurrence and expansion of gaps.

[0079] [Alternative form 2] Further, a weed suppression structure 8b of modified form 2 in which the wedge portion is connected to the side wall portion instead of the protruding portion will be described with reference to FIG. 4(b).

[0080] In this weed suppression structure 8b, in the right grating support frame 20R of the frame body 20, the base end 20c1 of the wedge portion 20c is connected to the upper and lower middle of the outer surface 20a1 of the side wall portion 20a, and its tip 20c2 extends diagonally upward to the right into the pavement layer 7.

[0081] Since the inner surface 20c3 of the wedge portion 20c is positioned at an angle to the direction of the thermal contraction force 9, the vertical cross-sectional area in the direction of the thermal contraction force 9 is smaller than the area of ​​the inner surface 20c3, and the reaction force 21 pushing back the pavement layer 7 by the inner surface 20c3 is also smaller.

[0082] Conversely, only the pavement layer 7 is in contact with the upper surface 20b1 of the protruding portion 20b of the grating support frame 20, and since the protruding portion 20b is arranged parallel to the direction of the thermal contraction force 9, the friction force 22 between the upper surface 20b1 and the pavement layer 7 is greater than in the case of the above-mentioned weed suppression structures 8, 8a.

[0083] This allows the magnitude of the reaction force 21 and the friction force 22 to be freely adjusted simply by changing the attachment position of the base end 20c1 of the wedge portion 20c, making it possible to attach the base end in a way that is suitable for the characteristics of the pavement layer 7.

[0084] In other words, when the base ends 5c1 and 20c1 of the wedge portions 5c and 20c are connected to at least one of the side wall portion 20a and the protrusion portion 5b, as in the weed suppression structure 8b of this embodiment, the base end 20c1 of the wedge portion 20c is connected to the side wall portion 20a, the inner surface 20c3, which is the side surface of the wedge portion 20c, is positioned at an angle to the direction of the thermal contraction force 9, which is the direction of movement of the paving layer 7, so that the vertical cross-sectional area with respect to the direction of the thermal contraction force 9 is small and the reaction force 21 due to the inner surface 20c3 of the wedge portion 20c is small.

[0085] Conversely, nothing is connected to the upper surface 20b1 of the protruding portion 20b, which is the surface of the protruding portion 20b located outside the base end 20c1 of the wedge portion 20c, and furthermore, since the protruding portion 20b is arranged parallel to the direction of the thermal contraction force 9, the friction force 22 between the upper surface 20b1 of the protruding portion 20b and the pavement layer 7 is large.

[0086] On the other hand, when the base ends 5c1, 15c8, 15c9 of the wedge portions 5c, 15c1, 15c2 are connected to the protrusion portions 5b, 15b, as in the weed suppression structures 8, 8a described above, in the case of weed suppression structure 8, the inner surface 5c3, which is the side surface of the wedge portion 5c, is positioned perpendicular to the direction of the thermal contraction force 9, which is the direction of movement, so the vertical cross-sectional area in the direction of the thermal contraction force 9 becomes larger and the reaction force 11 due to the inner surface 5c3 of the wedge portion 5c is large.

[0087] Conversely, when the base end 5c1 of the wedge portion 5c is connected halfway to the upper surface 5b3, which is the surface of the protruding portion 5b, the area of ​​the outer upper surface 5b5, which is the surface of the protruding portion 5b that is outside the base end 5c1, becomes smaller than when there is nothing on the surface, and since the protruding portion 5b is arranged parallel to the direction of the thermal contraction force 9, the friction force 10 between the outer upper surface 5b5 of the protruding portion 5b and the pavement layer 7 is small.

[0088] Furthermore, when the base end of the wedge portion is connected to both the side wall portion and the protruding portion, the magnitude of the reaction force and the friction force can be adjusted more precisely.

[0089] In this way, the magnitude of the reaction force and friction force can be freely adjusted simply by changing the attachment position of the base end of the wedge portion. Furthermore, by simply selecting the attachment conditions of the base end that are suitable for the surface roughness and mechanical properties such as elastic modulus of the pavement layer 7, more sufficient resistance to movement of the pavement layer 7 can be obtained, and the occurrence and expansion of gaps can be prevented more reliably.

[0090] [Alternative form 3] A weed control structure 8c of modified embodiment 3 having a retaining structure 26 in which the cross-sectional area of ​​the wedge portion increases from the base end side toward the tip end side will be described with reference to FIG. 5(a).

[0091] In this weed suppression structure 8c, the right grating support frame 25R of the frame body 25 has a wedge portion 25c erected midway on the upper surface 25b1 of the protruding portion 25b from the side wall portion 25a.

[0092] However, this wedge portion 25c is formed so that its base end 25c1 is joined to the upper surface 25b1 by welding or the like, and its tip 25c2 extends upward from this base end 25c1 to protrude into the pavement layer 7, but while the inner surface 25c3 of the wedge portion 25c is erected vertically, the outer surface 25c4 of the wedge portion 25c extends diagonally upward to the right.

[0093] As a result, the wedge portion 25c has a slip-out prevention structure 26 in which the thickness increases toward the tip 25c2 and the cross-sectional area increases. After being embedded in the pavement layer 7, the wedge portion 25c is less likely to slip out of the pavement layer 7. Therefore, even if a large thermal contraction force 9 is acting on the inner surface 25c3, the position of the wedge portion 25c will not shift, and a stable reaction force 27 can be generated together with a friction force 28.

[0094] That is, when wedge portion 25c has retaining structure 26 in which the cross-sectional area increases from base end 25c1 toward tip 25c2, even if the adhesion between the surface of wedge portion 25c and the inner surface of pavement layer 7 is insufficient or the amount of thermal contraction increases due to a large temperature change, wedge portion 25c is less likely to fall out of pavement layer 7 because base end 25c1 is thinner than tip 25c2. This prevents a decrease in reaction force due to misalignment between wedge portion 25c and pavement layer 7, and more reliably prevents gaps from occurring or widening.

[0095] [Alternative form 4] In addition, a weed suppression structure 8d of variant 4 having a hooking structure 31 in which the side surface facing the side wall portion is inclined toward the side wall portion as the wedge portion moves from the base end to the tip end will be described with reference to Figure 5(b).

[0096] In this weed suppression structure 8d, the right grating support frame 30R of the frame body 30 has a wedge portion 30c erected midway on the upper surface 30b1 of the overhanging portion 30b.

[0097] However, this wedge portion 30c is formed so that its base end 30c1 is joined to the upper surface 30b1 by welding or the like, and its tip end 30c2 protrudes into the pavement layer 7 obliquely upward to the left.

[0098] As a result, the wedge portion 30c has a hooking structure 31 in which the inner surface 30c3, which is the side surface facing the side wall portion 30a, is inclined toward the side wall portion 30a, and after being embedded in the pavement layer 7, the tip 30c2 of the wedge portion 30c sinks into this pavement layer 7.Therefore, even if a large thermal contraction force 9 is acting on the inner surface 30c3, the position of the wedge portion 30c will not shift, and a stable magnitude of reaction force 32 can be generated together with a friction force 33.

[0099] That is, when wedge portion 30c has a hooking structure 31 in which inner surface 30c3, which is the side surface facing side wall 30a, slopes toward side wall 30a as it moves from base end 30c1 to tip 30c2, even if the adhesion between the surface of wedge portion 30c and the inner surface of pavement layer 7 is insufficient or if the amount of thermal shrinkage increases due to a large change in temperature, wedge portion 30c will move relatively as pavement layer 7 moves, and will sink into pavement layer 7 from tip 30c2. This prevents a decrease in reaction force due to misalignment between wedge portion 30c and pavement layer 7, and more reliably prevents gaps from occurring or widening.

[0100] [Alternative form 5] In addition, a weed suppression structure 8e of variant 5, in which the wedge portion has an engagement structure 36 including an engagement portion capable of frictionally engaging with the paving layer on at least a portion of the side surface facing the side wall portion, will be described with reference to Figure 5(c).

[0101] In this weed suppression structure 8e, the right grating support frame 35R of the frame body 35 has a wedge portion 35c erected midway on the upper surface 35b1 of the protruding portion 35b.

[0102] However, the wedge portion 35c has an inner surface 35c3, which in this embodiment is formed with an engagement portion 35c5 consisting of a plurality of protrusions 35c4 at approximately the center between the base end 35c1 and the tip end 35c2.

[0103] As a result, the wedge portion 35c has an engagement structure 36 including an engagement portion 35c5 that can frictionally engage with the pavement layer 7 on at least a part of the inner surface 35c3, which is the side surface facing the side wall portion 35a.After the wedge portion 35c is embedded in the pavement layer 7, the engagement portion 35c5 digs into the pavement layer 7, making it difficult for the wedge portion 35c to come out.As a result, even if a large thermal contraction force 9 is acting on the inner surface 35c3, the position of the wedge portion 35c will not shift, and a stable magnitude of reaction force 37 can be generated together with a frictional force 38.

[0104] That is, when wedge portion 35c has engagement structure 36 including engagement portion 35c5 capable of frictionally engaging with pavement layer 7 on at least a portion of inner surface 35c3 facing side wall portion 35a, even if the adhesion between the surface of wedge portion 35c and the inner surface of pavement layer 7 is insufficient or even if the amount of thermal shrinkage increases due to a large temperature change, wedge portion 35c is less likely to fall out of pavement layer 7 because engagement portion 35c5, such as an uneven surface, is present on inner surface 35c3 of wedge portion 35c. This prevents a decrease in reaction force due to misalignment between wedge portion 35c and pavement layer 7, and more reliably prevents the occurrence and expansion of gaps.

[0105] As described above, the drainage ditch of the present invention is equipped with a weed control structure that can reliably prevent gaps from occurring between the side wall of a frame that supports a water-permeable lid such as a grating through which rainwater and the like can pass and flow in, and the pavement layer surrounding the outer surface of this side wall, using only a simple structure and without time-consuming advance preparation, and can reliably prevent weeds from occurring in these gaps and growing there, even if the pavement layer is thick, for a long period of time.

[0106] Although the present invention has been described through the above-mentioned embodiments, the present invention is not limited to these. Furthermore, the above-mentioned effects are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the present embodiments. [Explanation of symbols]

[0107] 1. Drain 2 Road surface 3a Drainage channel 4 Grating (water-passing cover) 5・15・20・25・30・35 Frame 5a・15a・20a・25a・30a・35a Side wall part 5b, 15b, 20b, 25b, 30b, 35b Extension 5b5 Outer upper surface (surface outer than the base end) 5c, 15c1, 15c2, 20c, 25c, 30c, 35c Wedge 5c1・15c8・15c9・20c1・25c1・30c1・35c1 Base end 5c2·15c4·15c6·20c2·25c2·30c2·35c2 Tip 5c3 Inner surface (side facing the direction of pavement layer movement) 7 Pavement Layer 9 Heat shrink force 10·22 Frictional force 11·16·17·21 Reaction force 15c1 Inner wedge part (wedge part) 15c2 Outer wedge part (wedge part) 26 Anti-slip structure 30c3·35c3 Inner surface (side facing the side wall) 31 Latch structure 35c5 Engagement part 36 Engagement structure U upward

Claims

1. A drainage channel is buried under the road surface and has a frame body that supports a water-passing cover that communicates with the drainage channel inside a side wall portion, The frame body has: one or more wedge portions extending upward from a base end, with a tip end protruding into the pavement layer below the road surface, and a side surface facing the moving direction of the pavement layer pushing back the pavement layer with a reaction force to suppress thermal contraction movement of the pavement layer; a protruding portion extending perpendicularly from the side wall portion, the tip of which projects into the pavement layer, and which suppresses thermal contraction and movement of the pavement layer by friction between the surface of the wedge portion outside the base end and the pavement layer; A drainage ditch characterized by:

2. The base end of the wedge portion is connected to at least one of the side wall portion and the protruding portion. The drainage channel according to claim 1 .

3. The wedge portion has a retaining structure in which the cross-sectional area increases from the base end side toward the tip end side. The drainage channel according to claim 1 or 2.

4. The wedge portion has a hook structure in which the side surface facing the side wall portion is inclined toward the side wall portion from the base end side toward the tip end side. The drainage channel according to claim 1 or 2.

5. The wedge has an engagement structure including an engagement portion that can frictionally engage with the pavement layer on at least a part of the side surface facing the side wall. The drainage channel according to claim 1 or 2.

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