JP2017198008A - Installation structure, base member, and installation method of bridge guard fence - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an installation structure of a bridge guard fence that ensures sufficient strength even when a ground cover is narrow.SOLUTION: An installation structure for a bridge guard fence includes: a plurality of anchor bolts B1 fitted on a top surface of a ground cover W of a road bridge and arranged to form two or more rows in a direction of extension of the ground cover W; a base member 3 fixed to project outward in a bridge width direction from the ground cover W; a support post 1 fixed on the base member 3; and a beam fitted on the support post 1. The base member 3 includes a plurality of anchor bolt fitting holes 311 through which each of the plurality of anchor bolts B1 penetrates. An interval between the plurality of anchor bolt fitting holes 311 arranged in the direction of extension of the ground cover W is of a ratio between 0.5 and 3.0 with respect to an embedded depth of the plurality of anchor bolts B1 into the ground cover W.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an installation structure of a bridge protection fence, particularly a base member for the bridge protection fence, and an installation method of the bridge protection fence, which are particularly suitable for renewing an existing bridge protection fence.

  In recent years, serious accidents such as casualties have occurred due to damage to social infrastructure such as aging road structures. For this reason, renewal of aging social infrastructure is urgently needed, and this renewal is promoted by the government and local governments.

  Regarding the renewal method of the existing bridge guard fence related to this, for example, the method described in Patent Document 1 has been proposed by the applicant of the present application. This method first removes the existing bridge guard fence from the concrete ground cover, and further removes the portion of the existing anchor bolt protruding from the ground cover. Thereafter, a new anchor bolt (for example, post-installed anchor bolt) is installed on the ground cover, and a new bridge protection fence is attached to the ground cover.

  By the way, bridges (road bridges) that are managed by local governments (prefectures and municipalities) in particular are less likely to cover the ground due to, for example, the installation time being shorter or the length of the bridge being shorter than bridges managed by the government. In many cases, the width is narrow. For such a narrow ground cover, conventionally, when updating an existing bridge guard fence, new anchor bolts cannot be installed in multiple rows in the direction of the ground cover extension. It was dealt with by embedding it deeply.

  However, when post-installed anchor bolts are installed on a narrow ground cover, it is necessary to embed the anchor bolts deeply in order to secure an effective shear area of concrete that can withstand vehicle collisions. Since it is low and the distance to the floor slab is small, there are many cases where it is difficult to install the anchor bolt with a sufficient embedding depth. For this reason, for example, when a vehicle collides with a guard fence for a bridge, the anchor bolt is pulled out from the ground cover by the force applied to the anchor bolt due to this collision, so that the guard fence for the bridge falls into the river and the vehicle There was also a problem that could fall into the river. Moreover, even if an anchor bolt can be installed, there are many cases where the building limit defined in the road structure ordinance cannot be secured due to the narrow width of the ground cover.

  In addition, there is a method of re-forming the widened ground cover after removing the existing ground cover, but because the construction becomes large, the construction period is long and traffic control is required over a long period of time. large. And since the weight of the widened ground cover increases from before the widening, the load on the bridge slab and the pier is increased.

  There is also a method to fix the bracket with anchor bolts on the outer surface of the bridge in the width direction of the bridge (the surface on the opposite side of the road facing the road or the surface on the river side) and attach a new strut to the bracket. However, since there is a possibility that a pulling load is always applied to the anchor bolt for fixing the metal fitting, there is a difficulty in safety and durability. And, in order to construct anchor bolts on the outer surface in the bridge width direction of the ground cover, it is necessary to assemble a temporary scaffold on the river, so the construction cost increases.

Japanese Patent No. 5190599

  In view of the above problems, the present invention provides an installation structure of a bridge protection fence, a base member for the bridge protection fence, and an installation method of the bridge protection fence that can sufficiently secure strength even in a narrow ground cover. The task is to do.

  The present invention provides a plurality of anchor bolts that are attached to the upper surface of a ground cover in a road bridge and are arranged in two or more rows in the extending direction of the ground surface, and project from the ground surface to the outside in the bridge width direction. A base member fixed by the plurality of anchor bolts, a support post fixed on the base member, and a cross beam attached to the support post, wherein the base member includes each of the plurality of anchor bolts. A plurality of anchor bolt mounting holes penetrating therethrough, wherein the plurality of anchor bolt mounting holes is a ratio based on the embedding depth of the plurality of anchor bolts in the ground cover with respect to the arrangement interval in the extending direction of the ground cover. This is an installation structure of bridge guard fences arranged at intervals of 0.5 to 3.0.

  Further, the present invention is provided with a plurality of anchor bolt mounting holes that are attached to the top surface of the ground in the road bridge and through which each of the plurality of anchor bolts arranged so as to be in two or more rows in the extending direction of the ground cover. A pillar mounting bolt hole for mounting a bridge guard fence post, and when fixed to the ground cover, one end is located outward from the outer surface in the bridge width direction of the ground cover, the plurality The anchor bolt mounting holes are arranged at intervals of 0.5 to 3.0 with respect to the arrangement interval in the extending direction of the ground cover in a ratio based on the embedding depth of the plurality of anchor bolts in the ground cover. Base member.

  According to these structures, a support | pillar can be displaced from a ground cover by providing a base member between a ground cover and a support | pillar. A sufficient amount of anchor bolts to be arranged in two or more rows in the extending direction of the ground cover on the top surface of the ground cover is sufficient even if the ground cover has a narrow width by the amount of the displacement. Space is reserved. For this reason, even if it is a narrow ground cover, a pillar can be fixed using a plurality of anchor bolts. Therefore, the column is fixed with sufficient strength by the plurality of anchor bolts.

  Furthermore, the plurality of anchor bolt mounting holes are arranged at intervals of 0.5 to 3.0 in terms of the interval of arrangement in the extending direction of the ground cover, with the ratio based on the embedding depth of the plurality of anchor bolts in the ground cover. Because it is arranged, the area where the cone breakage occurs in the concrete that constitutes the cover can be separated from the adjacent cone breakage area at least according to the distance between the anchor bolt mounting holes in the extension direction of the cover. The strength against the external force in the pulling direction acting on the anchor bolt and the external force in the horizontal direction can be improved.

  The present invention also includes a plurality of anchor bolts that are attached to the upper surface of the ground cover of the road bridge and are arranged in two or more rows in the extending direction of the ground cover, and project outward from the ground surface in the bridge width direction. A base member fixed by the plurality of anchor bolts, a support post fixed on the base member, and a cross beam attached to the support post, wherein the base member is each of the plurality of anchor bolts Is provided with a plurality of anchor bolt mounting holes, wherein the plurality of anchor bolt mounting holes is an installation structure of a guard fence for a bridge in which the hole interval in the inner row is larger than the hole interval in the outer row in the bridge width direction. .

  Further, the present invention is provided with a plurality of anchor bolt mounting holes that are attached to the top surface of the ground in the road bridge and through which each of the plurality of anchor bolts arranged so as to be in two or more rows in the extending direction of the ground cover. A pillar mounting bolt hole for mounting a bridge guard fence post, and when fixed to the ground cover, one end is located outward from the outer surface in the bridge width direction of the ground cover, the plurality The anchor bolt mounting hole is a base member having a hole interval in the inner row larger than a hole interval in the outer row in the bridge width direction.

  According to these structures, a support | pillar can be displaced from a ground cover by providing a base member between a ground cover and a support | pillar. A sufficient amount of anchor bolts to be arranged in two or more rows in the extending direction of the ground cover on the top surface of the ground cover is sufficient even if the ground cover has a narrow width by the amount of the displacement. Space is reserved. For this reason, even if it is a narrow ground cover, a pillar can be fixed using a plurality of anchor bolts. Therefore, the column is fixed with sufficient strength by the plurality of anchor bolts.

  Furthermore, with respect to the hole spacing of the plurality of anchor bolt mounting holes arranged so that there are two or more rows in the extending direction of the ground cover, the hole spacing in the inner row is larger than the hole spacing in the outer row in the bridge width direction. Since it is large, the area where the cone breakage occurs in the concrete constituting the ground cover can be appropriately separated from the area where the adjacent cone breakage occurs according to the distance between the anchor bolt mounting holes in each row direction and in the bridge width direction. Therefore, the strength against the external force in the pulling direction acting on the anchor bolt and the external force in the horizontal direction can be improved.

  Further, the base member can be projected outward in the bridge width direction with respect to the ground cover so as to have a space between the bottom surface of the base member and the outer surface in the bridge width direction of the ground cover.

  According to this configuration, there is a space between the bottom surface of the base member and the outer surface in the bridge width direction of the ground cover (the surface on the opposite side of the road facing the road or the surface on the river side). Thus, even when an external force that falls to the outer side in the bridge width direction is applied to the base member, the external force is not transmitted to the outer surface in the bridge width direction of the ground cover, so that the ground cover can be prevented from being destroyed.

  Further, the support column is fixed to the base member by a bolt, and the base member is capable of contacting the bolt in a downward extending direction of the bolt for fixing the support column, and faces the space. It is possible to provide a lid member that performs.

  According to this structure, it can prevent that the volt | bolt of the state before fixing a support | pillar falls out to the said space by a cover member.

  The present invention also includes a step of embedding a plurality of anchor bolts in the ground cover, and disposing the base member on the ground cover, and fixing the base member to the ground cover by screwing a nut into the anchor bolt. A step of mounting the column to the base member by placing a column on the base member and screwing a nut into a bolt mounted in the column mounting bolt hole; A method of installing a guard fence for a bridge having a mounting process.

  According to this method, it is possible to provide a guard fence for a bridge in which a column is fixed with sufficient strength even in a narrow ground cover.

  According to the present invention, by providing the base member between the ground cover and the support column, the support column is fixed to the ground cover with sufficient strength. Therefore, it is possible to provide an installation structure of a bridge protection fence, a base member for the bridge protection fence, and an installation method of the bridge protection fence that can sufficiently secure strength even in a narrow ground cover.

It is a perspective view at the time of seeing from the diagonally upper direction which shows the state which provided the guard fence for bridges (except a cross beam) concerning one embodiment on the ground cover concerning this invention. It is a perspective view at the time of seeing from the diagonally lower direction which shows the state which abbreviate | omitted the ground cover by the protective fence for bridges (except a horizontal beam). The protection fence for the bridge (excluding the horizontal beam) is shown on the ground cover, (a) is a front view, (b) is a plan view, and (c) is a longitudinal section taken along line II in (b). It is a surface figure (a horizontal beam is displayed with a dashed-two dotted line). The base member of the protection fence for bridges is shown, (a) is a perspective view at the time of seeing from diagonally upward, (b) is a perspective view at the time of seeing from diagonally downward. The base member of the protection fence for bridges is shown, (a) is a top view, (b) is a bottom view, (c) is a longitudinal cross-sectional view of the II-II arrow of (b). The present invention shows a state in which a guard fence for a bridge according to an embodiment provided with an entire cover is provided on the ground cover, (a) is a front view, (b) is a plan view, and (c) is a view of (b). It is a longitudinal cross-sectional view of III-III arrow. It is the schematic shown in order for (a)-(f) about the installation construction method of the guard fence for bridges.

  Next, embodiments of the present invention will be described. Note that this embodiment is merely an example for understanding the present invention, and variations other than the present embodiment regarding the shape, structure, material, and the like of each part are within the scope of the present invention. It goes without saying that it is allowed.

  In addition, the expression “front / rear / left / right” in the following description is based on the directions described in FIGS. 1, 4A, 4B, and 5A, and the expression “vertical direction” is described in FIG. Based on direction.

  As shown in FIG. 1, FIG. 2, FIG. 3 (a) to (c), the installation structure of the bridge guard fence according to the present embodiment is configured as shown in FIG. 1, FIG. In addition to the bridge guard fence formed by combining (only)), a base member 3 functioning as an attachment disposed between the ground cover W and the support column 1 is provided.

  The base member 3 is made of cast iron (more specifically, made of ductile cast iron). However, the material of the base member 3 is not limited to this, and can be formed of various materials such as an aluminum casting, iron, and a stainless alloy. The base member 3 has a shape shown in FIGS. 4A and 4B and FIGS. 5A to 5C. When the base member 3 is disposed on the ground cover W as shown in FIG. 1 and FIGS. 3A to 3C, the base member 3 is positioned so that the front faces the road on the bridge, and the horizontal direction is It is located in the extending direction (left-right direction) of the ground cover W. The base member 3 is fixed on the ground cover W so as to protrude rearward from the ground cover W, that is, outward in the bridge width direction (front-rear direction).

  An anchor bolt mounting portion 31 is formed at a position near the front of the base member 3. The anchor bolt mounting portion 31 is formed with four anchor bolt mounting holes 311 and is fastened with nuts to the anchor bolt B1 embedded in the ground cover W from the upper surface. The anchor bolt B1 is embedded in the ground cover W so as to extend in the vertical direction. The anchor bolt mounting hole 311 is a long hole extending in the left-right direction, that is, a long hole extending along the extending direction (left-right direction) of the ground cover W when installed on the ground cover W. In addition, the extending direction of the ground cover W is a direction intersecting (orthogonal in the present embodiment) with respect to the bridge width direction. Thus, when the anchor bolt mounting hole 311 is a long hole, for example, when there is a reinforcing bar inside the ground cover W at a position where the anchor bolt B1 is to be installed, the anchor bolt B1 can be shifted and installed to avoid the reinforcing bar. .

  In the anchor bolt mounting portion 31 of this embodiment, four anchor bolt mounting holes 311 are formed in two rows in the extending direction of the ground cover W, but the number of anchor bolt mounting holes 311 formed is limited to this. Not. For example, the anchor bolt mounting portion 31 can be configured so that two anchor bolts B1 can be mounted so as to share three elongated holes formed as the anchor bolt mounting holes 311. You can also

  The anchor bolt mounting portion 31 has a recess 312 as shown in FIGS. 4 (a) and 5 (a) (c). The recess 312 has a space opened forward. For this reason, the tool for tightening the anchor bolt B1 hardly interferes with the base member 3, and the tightening operation by the worker can be performed smoothly. Two recesses 312 are formed with two anchor bolt mounting holes 311 that are displaced in the front-rear and left-right directions.

  In this embodiment, four anchor bolt mounting holes 311 are formed for each base member 3. As shown in FIG. 5 (a), two of them located in the rear row (outside in the bridge width direction) are provided with a relatively small interval (hole interval) W311b in the left-right direction, and the front side (in the bridge width direction). Are located at a relatively large gap (hole gap) W311f in the left-right direction. That is, the anchor bolt mounting holes 311 belonging to the front and rear rows are arranged so as to be shifted in the front-rear direction. However, the present invention is not limited to this, and for example, by providing two pieces located in the front and two pieces located in the rear at the same interval, the anchor bolt mounting holes 311 belonging to each row are arranged in the front-rear direction. May be. Further, it is preferable that the left and right intervals W311b and W311f of the anchor bolt mounting hole 311 are set larger than the width dimension of the support column 1 (dimension in the extending direction of the ground cover W). This is because when the anchor bolts B1 are arranged at an interval smaller than the width dimension of the support column 1, sufficient anchor strength cannot be expected.

  The plurality of anchor bolt mounting holes 311 is a ratio based on the embedding depth DB1 (see FIG. 3C) of the plurality of anchor bolts B1 in the ground cover W with respect to the arrangement interval in the extending direction of the ground cover W. It is 0.5-3.0, Preferably, it arrange | positions by the space | interval which becomes 0.5-2.0 by the said ratio from the conditions from which the punching shear area of the ground cover W becomes the maximum. It should be noted that an average value is used as the embedding depth DB1 of the plurality of anchor bolts B1 when there are variations in individual dimensions. According to this arrangement, the concrete constituting the ground cover W is destroyed by cone according to the distance between the anchor bolt mounting holes 311 in at least the extending direction of the ground cover W. A region where the corresponding (development depth DB1) occurs can be appropriately separated from an adjacent region where cone fracture occurs. That is, it is possible to avoid overlapping regions where a plurality of cone breaks occur as much as possible. In particular, the anchor bolt mounting holes 311 belonging to each row (in this embodiment, the anchor bolt mounting holes 311 located in the row on the rear side (outside in the bridge width direction) and the row on the front side (inside in the bridge width direction) are located. When the anchor bolt mounting holes 311) are arranged so as to be shifted in the left-right direction, even if the distance between the front and rear rows is the same as compared to the case where the anchor bolt mounting holes 311 belonging to each row are arranged straight forward and backward, The region where the cone breakage occurs can be easily separated. By arranging the plurality of anchor bolt mounting holes 311 as in the present embodiment, it is possible to improve the external force in the pulling direction acting on the anchor bolt B1 and the strength against the external force in the horizontal direction. Therefore, the base member 3 can be reliably supported by the plurality of anchor bolts B1 even in the case of the narrow ground cover W in which the volume of the concrete cannot be sufficiently secured.

  In the base member 3, the distance from the bottom surface 3a to the top surface 3b (the distance from the upper end of the recess 312 to the bottom surface 3a of the base member 3) is greater than the height at which the anchor bolt B1 protrudes from the top surface of the ground cover W. ing. Therefore, as shown in FIGS. 3A and 3C, the upper end portion of the anchor bolt B1 protruding from the ground cover W can be accommodated in the recess 312 and can be prevented from protruding from the upper surface 3b of the base member 3. . Therefore, when the cover 5 described later is not provided, the aesthetic appearance when the base member 3 is mounted on the ground cover W is excellent. Furthermore, even if the vehicle rides on the base member 3, the anchor bolt B1 is surrounded by “walls” from three sides, so that there is nothing around the anchor bolt B1. In comparison, since the upper end portion of the anchor bolt B1 can be prevented from hitting the tire, tire damage such as burst is unlikely to occur.

  A column attachment portion 32 is formed in the rear region of the base member 3. The upper surface of the column attachment portion 32 is shaped such that the lower end plate 11 of the column 1 can be disposed. A column mounting bolt hole 321 is formed in the column mounting portion 32, and a column mounting bolt B <b> 2 is mounted to fix the lower end plate 11 of the column 1. As shown in FIG. 3C, the base member 3 has a cross-sectional performance required from the bottom surface 3a to the top surface 3b in the column mounting portion 32, and the load of the column 1 and the cross beam 2 and, for example, strong wind The bending force of the base member 3 is set within the elastic range with respect to the bending stress acting on the base member 3 when the column 1 and the cross beam 2 try to fall outside (backward) in the width direction of the bridge at the time of a vehicle collision. It is possible to keep it below the proof stress value.

  Four column mounting bolt holes 321 are provided in the column mounting part 32. Of these, the two positioned forward are provided with a relatively small interval in the left-right direction, and the two positioned rearward are provided with a relatively large interval in the left-right direction. In addition, it is not limited to this, For example, two located in the front and two located in the back can also be provided at the same interval. As shown in FIG.5 (c), the column attachment bolt hole 321 has the enlarged part 321a expanded in the bottom face 3a side. As shown in FIGS. 4B and 5B, the enlarged portion 321a has a shape having a flat surface 321b facing in the left-right direction when viewed from the bottom. When a hexagonal bolt is used as the post mounting bolt B2, as shown in FIG. 3C, the bolt head is positioned at the enlarged portion 321a. The bolt head is brought into contact with the flat surface 321b, thereby preventing the column mounting bolt B2 from rotating. For this reason, the support | pillar 1 can be fixed to the base member 3 only by screwing a nut from the upper surface 3b side with respect to the support | pillar mounting bolt B2.

  Further, as shown in FIG. 2, the base member 3 can abut on the column mounting bolt B2 in the downward extending direction of the column mounting bolt B2 for fixing the column 1 and is in the space S (FIG. 3 ( It is also possible to provide a lid member 4 facing c). When this lid member 4 is provided, it is possible to effectively prevent the column mounting bolt B2 in a state before fixing the column 1 from dropping into the space S below. In addition to the lid member 4, for example, the expansion portion 321 a is provided with a drop-off preventing mechanism for preventing the column mounting bolt B <b> 2 from dropping from the column mounting bolt hole 321, so that the column mounting bolt B <b> 2 does not fall off. It may be.

  The column attachment portion 32 is located away from the anchor bolt attachment portion 31 at the rear (outside in the bridge width direction of the ground cover W). For this reason, by providing the base member 3 between the ground cover W and the support 1, the support 1 can be shifted from the cover W. Even if the width of the ground cover W is narrow, the two or more rows in the extending direction of the ground cover W (in other words, the inside and outside of the bridge width direction) A sufficient space for mounting a plurality of (four in this embodiment) anchor bolts B1 arranged so as to be in at least two rows. The “two rows in the extending direction of the ground cover W” means that there are two rows in the extending direction (left and right direction) of the ground cover W so that they are aligned in the bridge width direction (front and rear direction). Meaning. The “two rows” includes a case where each row is composed of only one anchor bolt B1. For this reason, even if it is the ground cover W with a narrow width | variety, the support | pillar 1 can be fixed using the some anchor bolt B1 arrange | positioned so that it may become 2 or more rows toward the extension direction of the ground cover W. Therefore, the support column 1 is fixed with sufficient strength by the plurality of anchor bolts B1.

  Further, the column mounting bolt B2 is provided separately from the anchor bolt B1. For this reason, it is assumed that the column mounting bolt B2 can bear the deformation load of the base member 3, and assuming this assumption, the anchor bolt B1 does not have a pulling load generated when a vehicle collides with the bridge guard fence. Since it can bear, the load burdened by the column mounting bolt B2 and the anchor bolt B1 can be dispersed. Therefore, it is considered that the embedding depth of the anchor bolt B1 into the ground cover W can be reduced by the amount of load that should be borne by the anchor bolt B1.

  Further, the anchor bolt B1 and the column mounting bolt B2 do not interfere with each other. Therefore, since the fixing of the base member 3 to the ground cover W and the fixing of the support column 1 to the base member 3 can be performed in separate steps, the bridge guard fence can be updated efficiently.

  Note that unlike the present embodiment, a part or all of the anchor bolt mounting hole 311 can also serve as the column mounting bolt hole 321. In this case, a part or all of the anchor bolt B <b> 1 can be used to fix the column 1 to the base member 3. However, in this case, in order to adapt to the construction limit of the road structure ordinance described later, for example, it is necessary to prepare a column 1 having a special shape. Therefore, as in this embodiment, the anchor bolt mounting hole 311 and the column mounting column are used. It is desirable to form it separately from the bolt hole 321.

  A suspension hole 33 is formed behind the base member 3 and closer to the end in the left-right direction than the column attachment portion 32. By passing a suspension belt or the like through the suspension hole 33, the base member 3 can be easily suspended using a heavy machine or the like, and the base member 3 can be easily placed on the ground cover W. The suspension hole 33 can also be used as a handle of an operator. In this case, the base member 3 can be easily transported manually. Further, as shown in FIG. 4B, a meat stealing portion 34 opened on the bottom side is formed on the left and right portions of the column mounting bolt holes 321 that do not directly contribute to the load burden on the base member 3. This contributes to the weight reduction of the base member 3. Furthermore, since the section modulus (second moment of section) can be increased by forming a portion having a space such as the meat stealing portion 34, the strength (rigidity) of the base member 3 can be improved.

  The base member 3 is attached to the ground cover W as shown in FIG. 1 and FIGS. 3A to 3C, the front end is located on the ground cover W as shown, and the rear end is the ground cover. Projects beyond W (outside in the width direction of the bridge). The column 1 attached in this state is in a state of being offset backward (outside in the bridge width direction) with respect to the ground cover W. Can be adapted to building limits.

  As shown in FIG. 3C, the protrusion of the base member 3 to the outer side in the bridge width direction with respect to the ground cover W is the outer surface (the road on the bridge) of the bottom surface 3a of the base member 3 and the ground width W in the bridge width direction. A space S is formed between the first side W1 and the opposite side or the river side surface. With this configuration, even when an external force is applied to the base member 3 that falls outward in the bridge width direction, the external force is not transmitted to the outer surface W1 in the bridge width direction of the ground cover W, and the external force is transmitted to the outer surface W1. It can suppress that the concrete which comprises the ground cover W is destroyed because of this.

  The strut 1 and the cross beam 2 can have the same structure as that conventionally used. A lower end plate 11 is provided at the lower end of the column 1. The lower end plate 11 and the base member 3 are fastened with a fixing member. For this reason, a bolt through hole 111 is formed in the lower end plate 11 (see FIGS. 3C and 7D). In the present embodiment, the column mounting bolts B2 and nuts are used as the fixing members, but other fastening means may be used. Moreover, in this embodiment, although the hexagon bolt is used as the support | pillar mounting bolt B2, bolts other than a hexagon bolt can also be used. In some cases (specifically, when the base member 3 is formed of a weldable material), the lower end plate 11 can be welded to the base member 3. As shown in FIG. 3C, the cross beam 2 is attached to a recess formed in front of the support column 1, and is positioned along the extending direction of the ground cover W as shown in FIG.

  In addition, it is also possible to comprise the support | pillar 1 and the base member 3 integrally, and in this structure, there exists an advantage that the effort which fixes the support | pillar 1 to the base member 3 can be saved. However, in this configuration, the weight of the combined body of the support column 1 and the base member 3 is larger than the respective weights, and in some cases, heavy equipment is required, and it is difficult to adjust the position of the support column 1 with respect to the ground cover W. There is a demerit that Further, when the support column 1 and the base member 3 are integrally formed, for example, even if only one of the support column 1 and the base member 3 is damaged, the entire structure must be replaced. Only damaged parts can be replaced. Accordingly, it is desirable that the support column 1 and the base member 3 are configured separately.

  Here, the road construction limit is defined in the road structure ordinance (decree). According to this, it is required that the structure be separated from the outer end of the roadway, that is, the inner surface of the ground cover W by 250 mm or more.

  When anchor bolts are installed on the ground cover W, sufficient pullout strength cannot be exhibited unless the anchor bolts B1 are arranged in a region surrounded by the reinforcing bars inside the ground cover W, particularly the hoop bars. On the other hand, it is difficult to adapt to the construction limit while arranging anchor bolts in this region, particularly in the case of the narrow ground cover W.

  In the present embodiment, since the column 1 can be offset backward (in the direction of the bridge width direction) by the base member 3, the horizontal distance X from the inner surface of the ground cover W to the position closest to the road among the horizontal beams 2 (FIG. 3). (See (c)) can be 250 mm or more. For this reason, it is possible to easily satisfy the requirements of the road structure ordinance. In the present embodiment, all four anchor bolts B1 are positioned within the range of the horizontal distance X as shown in FIG. However, the present invention is not limited to this, and for example, at least a part of the plurality of anchor bolts such as the anchor bolt B1 positioned at the front can be configured to be positioned within the range of the horizontal distance X. As mentioned above, since the support | pillar 1 is offset back, the update of the protection fence in the bridge which has the narrow ground cover W can be accelerated | stimulated. Moreover, by using the base member 3, the column 1 and the cross beam 2 can be used as they are, without using a special shape for satisfying the building limit.

  Four anchor bolts B1 of this embodiment are used for each column 1. Three or five or more can also be used. Even if the embedding length of each anchor bolt B1 in the ground cover W is not increased, the burden load per anchor bolt B1 is reduced as the number of anchor bolts B1 increases. Sufficient pulling strength can be secured with a small embedding length. As the anchor bolt B1, a post-installed anchor such as a chemical anchor can be used.

  In the present embodiment, the cover 5 is attached so as to cover the base member 3. The cover 5 is formed, for example, by bending a steel plate into a substantially U-shape, and is implemented as an entire cover that covers the base member 3 and the upper portion of the ground cover W as shown in FIGS. be able to. In addition, it can also be implemented as a partial cover that covers only the base member 3 or covers only between the base members 3. The cover 5 can be attached by various means. For example, it can be performed by fitting to the base member 3, bolting, fixing to a rail installed on the ground cover W, or the like. In addition, the material of the cover 5 is not limited to this, For example, it can form with various materials, such as an aluminum alloy and a synthetic resin.

  The cover 5 has a shape protruding rearward from the ground cover W as shown in FIG. The rearwardly projecting portion corresponds to the projecting of the base member 3 with respect to the ground cover W as shown in FIG.

  A reinforcing member 6 is disposed between the cover 5 and the ground cover W. In this embodiment, the reinforcing member 6 is a long body having a hollow cross section made of a metal extrusion material such as an aluminum alloy. By forming it hollow, it is possible to reduce the weight while maintaining the strength of the reinforcing material 6. The reinforcing material 6 is not limited to extrusion, and can be formed by bending or pressing. It can also be formed of synthetic resin, carbon fiber, or FRP. In the present embodiment, a plurality of reinforcing members 6 are arranged in the width direction of the ground cover W. Specifically, the two reinforcing members 6 are juxtaposed on the ground cover W. The height of the reinforcing member 6 is substantially the same as the height of the base member 3. In this way, by configuring the reinforcing material 6 so that a plurality of the reinforcing materials 6 can be arranged in the width direction of the ground cover W, if the reinforcing material 6 having a certain width is prepared, the position of the reinforcing material 6 and the quantity to be arranged in parallel are determined. Since it can adjust and apply to the ground cover W of various width dimensions, it is excellent in versatility. As shown in FIG. 6C, the reinforcing member 6 is fixed to the ground cover W by anchor bolts B3, and the cover 5 is fixed to the reinforcing member 6 by screwing or the like.

  By providing the cover 5, the beauty of the bridge guard fence can be improved, and the rain can be prevented from being directly applied to the base member 3 and the anchor bolt B <b> 1, and the corrosion can be suppressed. Moreover, even if it is a case where a vehicle runs on a base member, it can suppress that each of a vehicle, the base member 3, and the ground cover W is damaged. In particular, since the cover 5 of the present embodiment is an entire cover and can prevent the upper surface of the cover 5 from being uneven, even if the vehicle rides on the base member, the vehicle tire is used as the base member. Since it is unlikely to get caught at the portion 3, the vehicle can be promptly returned to the road. In particular, when the cover 5 is formed of a lightweight material such as a synthetic resin, even if the cover 5 is detached from the ground cover W due to a vehicle collision, strong wind, or increase in river water, a pedestrian or other structure is used. The danger which arises when the cover 5 hits an object can be reduced.

  And the intensity | strength of the cover 5 can be improved by arrange | positioning the reinforcing material 6 between the cover 5 and the ground cover W. FIG. For this reason, even when the vehicle rides on the base member as described above, damage to the cover 5 can be suppressed.

  Next, an update method for an existing bridge protection fence, which is an example of a bridge protection fence installation method using the bridge protection fence according to the present embodiment, will be described. However, the construction order is not limited to the following description order, and the order can be appropriately changed. First, the pillars and lateral beams of the existing bridge protective fence are removed from the ground cover W. Next, among the existing anchor bolts embedded in the ground cover W, at least a portion protruding from the upper surface of the ground cover W is removed. If necessary, repair the surface of the ground cover W or the like. Next, as shown in FIG. 7A, four new anchor bolts B1 are embedded in the ground cover W. Next, as shown in FIG. 7 (b), the base member 3 that has been passed through the column mounting bolt B2 from below the column mounting bolt hole 321 is positioned on the ground cover W, and FIG. As shown, the nut N1 is screwed into the anchor bolt mounting hole 311 of the base member 3 through the anchor bolt B1. The nut N1 is temporarily fixed at this stage.

  Next, as shown in FIG. 7 (d), the support 1 is positioned on the support attachment portion 32 of the base member 3, and as shown in FIG. 7 (e), the bolt through hole 111 of the lower end plate 11 in the support 1. The nut N2 is screwed into the column mounting bolt B2 penetrating through the nut N2. The nut N2 is temporarily set at this stage. Next, as shown in FIG. 7 (f), the cross beam 2 is attached to the column 1. Thereafter, the positional relationship of each part is adjusted, and the nuts N1 and N2 screwed into the anchor bolt B1 and the column mounting bolt B2 and the bolts and nuts for mounting the horizontal beam 2 are finally tightened to complete.

  As described above, in the present embodiment, the base member 3 acts as a “ground cover extending member” which is an attachment that extends the ground cover W rearward (outward in the bridge width direction). For this reason, even if it is the narrow ground cover W, the support | pillar 1 is attached with the anchor bolt B1 arrange | positioned so that it may become 2 or more rows toward the extension direction of the ground cover W (four in this embodiment). I can support it. Moreover, building limits can be secured. For this reason, safety is high while ensuring strength. Moreover, there is no need to reconstruct the ground cover W. In addition, since the work of renewal of the existing fence guard can be completed only on the ground cover W (it can be constructed only on the bridge), a temporary scaffold is installed behind (outside) the bridge on the river. There is no need, and the construction period can be shortened and the construction cost can be reduced. Moreover, since each member for carrying out the renewal construction method can be configured so that the worker can carry it by manpower, it is not necessary to use heavy machinery and construction costs can be reduced.

  In addition, the construction method of this embodiment is not limited only to the update of the existing bridge protection fence described so far. For example, a new bridge protection fence is provided for the ground cover W in which the bridge protection fence is not provided. It can also be applied when providing. Furthermore, this construction method can also be applied to the newly formed ground cover W.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to each said embodiment, A various change can be added in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Support | pillar 2 Horizontal beam 3 Base member 3a Bottom surface of base member 3b Upper surface of base member 311 Anchor bolt mounting hole 312 Recess 321 Support bolt mounting bolt hole 4 Cover member 5 Cover B1 Anchor bolt B2 Bolt for fixing the support, fixing member, Strut mounting bolt W Ground cover W1 Outer surface in the width direction of the bridge S space DB1 Depth of anchor bolt embedding W311b Spacing distance of anchor bolt mounting holes, spacing of anchor bolt mounting holes in the outer rows in the bridge width direction W311f Anchor bolt mounting hole spacing, anchor bolt mounting hole spacing in the inner row in the bridge width direction

Claims (7)

A plurality of anchor bolts attached to the upper surface of the ground cover in the road bridge and arranged in two or more rows in the extending direction of the ground surface;
A base member fixed by the plurality of anchor bolts so as to project outward from the ground cover in the bridge width direction;
A column fixed on the base member;
A transverse beam attached to the column,
The base member includes a plurality of anchor bolt mounting holes through which each of the plurality of anchor bolts passes,
The plurality of anchor bolt mounting holes are spaced at intervals of 0.5 to 3.0 with respect to the arrangement interval in the extending direction of the ground cover, with a ratio based on the embedding depth of the plurality of anchor bolts in the ground cover. The installation structure of the guard fence for the arranged bridge. A plurality of anchor bolts attached to the upper surface of the ground cover in the road bridge and arranged in two or more rows in the extending direction of the ground surface;
A base member fixed by the plurality of anchor bolts so as to project outward from the ground cover in the bridge width direction;
A column fixed on the base member;
A transverse beam attached to the column,
The base member includes a plurality of anchor bolt mounting holes through which each of the plurality of anchor bolts passes,
The plurality of anchor bolt mounting holes have a bridge guard fence installation structure in which the hole interval in the inner row is larger than the hole interval in the outer row in the bridge width direction.   The overhang of the base member to the outside in the bridge width direction with respect to the ground cover is made to have a space between the bottom surface of the base member and the outer surface in the bridge width direction of the ground cover. Installation structure of the guard fence for the described bridge. The column is fixed to the base member with a bolt,
The bridge guard fence according to claim 3, wherein the base member includes a lid member that can contact the bolt in a downward extending direction of the bolt for fixing the support and faces the space. Installation structure. A plurality of anchor bolt mounting holes through which each of a plurality of anchor bolts that are attached to the top surface of the road bridge and are arranged in two or more rows in the extending direction of the ground cover;
A post mounting bolt hole for mounting a bridge guard fence post,
When fixed to the ground cover, one end is located outside the outer surface in the bridge width direction of the ground cover,
The plurality of anchor bolt mounting holes are spaced at intervals of 0.5 to 3.0 with respect to the arrangement interval in the extending direction of the ground cover, with a ratio based on the embedding depth of the plurality of anchor bolts in the ground cover. Base member for the guard fence for the arranged bridge. A plurality of anchor bolt mounting holes through which each of a plurality of anchor bolts that are attached to the top surface of the road bridge and are arranged in two or more rows in the extending direction of the ground cover;
A post mounting bolt hole for mounting a bridge guard fence post,
When fixed to the ground cover, one end is located outside the outer surface in the bridge width direction of the ground cover,
The plurality of anchor bolt mounting holes are base members for a guard fence for a bridge in which the hole interval in the inner row is larger than the hole interval in the outer row in the bridge width direction. Embedding a plurality of anchor bolts in the ground cover;
A step of placing the base member according to claim 5 or 6 on the ground cover, and fixing the base member to the ground cover by screwing a nut into the anchor bolt;
A step of mounting the column to the base member by placing a column on the base member and screwing a nut into the bolt attached to the column mounting bolt hole;
A method of installing a guard fence for a bridge, comprising attaching a horizontal beam to the support column.

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