JP5226584B2 - Steel slit dam, its construction method and repair method - Google Patents

Description

  The present invention relates to a steel slit dam suitably used for debris flow in rivers, driftwood countermeasures, etc., a construction method thereof, and a repair method.

  Conventionally, steel slit dams as disclosed in Patent Documents 1 and 2 have been proposed in order to prevent outflow of boulders and driftwood flowing through the river when debris flows are generated to the downstream side of the river. FIG. 13 is a perspective view showing one embodiment of the steel slit dam 101.

  This steel slit dam 101 is a column composed of a plurality of steel pipes standing between concrete dykes 105 constructed with a gap in the river width direction of the river 103 and having their lower ends buried in the foundation concrete 107. 111, a sheath pipe 119 embedded in the bank body 105, and a cross beam 115 made of a plurality of steel pipes, the end portion 115a of which is inserted into the sheath pipe 119 and spanned between the bank body 105 and connected to the support column 111. I have.

  FIG. 14 is a cross-sectional view showing the configuration of the end 115a of the transverse beam 115 inserted into the sheath tube 119. As shown in FIG. As shown in FIG. 14, in the steel slit dam 101, the end 115a of the transverse beam 115 is simply inserted into the sheath tube 119, and the transverse beam 115 is joined to the sheath tube 119 with a bolt or the like. In other words, a gap 120 is provided between the cross beam 115 and the sheath tube 119 as a margin for the relative movement of the cross beam 115 relative to the sheath tube 119.

  For this reason, even if there are manufacturing errors and construction errors of the steel slit dam 101, it is possible to absorb these manufacturing errors and the like by the gap 120 as a margin and improve workability. In addition, when the concrete constituting the dam body 105 or the steel material constituting the transverse beam 115 expands or contracts due to the temperature change, if the end 115a of the transverse beam 115 is fixed to the sheath tube 119, the thermal stress is applied to the transverse beam 115. In addition to excessive loads such as static loads and impact loads generated when trapping boulders and the like, excessive stress acts on the cross beam 115, so a large size and high strength member is required as the cross beam 115. . However, the steel slit dam 101 can absorb the expansion and contraction of the concrete and the steel pipe by the gap 120 as the allowance, so that the structure is not easily affected by temperature stress due to temperature change.

  Further, the steel slit dam 101 is configured by connecting a plurality of column members and beam members obtained by dividing the columns 111 and the horizontal beams 115 in the respective longitudinal directions by bolts and nuts. For this reason, after capturing boulders, driftwood, etc. by the columns 111 and the cross beams 115, and repairing the ends 115a of the cross beams 115 damaged by the capture of these boulders, etc., the bolts and nuts are removed to remove the cross beams 115 from the plurality of beams. By disassembling into a steel pipe and extracting the end 115a of the transverse beam 115 from the inside of the sheath pipe 119, repair work can be easily performed.

JP 2007-277972 A JP 2008-266981 A

  By the way, the above-described steel slit dam 101 has the following problems.

  FIG. 15A is a side view modeling the structure of the steel slit dam 101. When the steel slit dam 101 captures boulders, driftwood, etc., and a large load acts on the support column 111 and the cross beam 115 toward the downstream side, the cross beam 115 is formed between the end portion 115a of the cross beam 115 and the sheath tube 119. Since there is a gap 120 as an allowance between them, as shown in FIG. 15B, the gap 120 moves to the downstream side until it comes into contact with the sheath tube 119.

  Here, paying attention to the deformation behavior of the column 111 connected to the horizontal beam 115, the lower end of the column 111 is embedded in the foundation concrete 107, so that until the horizontal beam 115 contacts the sheath tube 119, Deformation behavior similar to that of a cantilever beam having a lower end side as a fixed end and an upper end side as a free end is exhibited. For a structural member that exhibits deformation behavior such as a cantilever beam, a large bending moment is applied to the root portion 111a of the column 111 in the vicinity of the fixed end as shown in FIG. Will work. For this reason, for example, when the gap 120 between the end 115a of the cross beam 115 and the sheath tube 119 is adjusted to be wide from the viewpoint of facilitating repair work, the amount of displacement of the cross beam 115 to the downstream side increases. The bending moment acting on the base portion 111a of the column 111 may exceed the elastic range of the column 111 and the column 111 may yield.

  When the support column 111 yields, the load generated at the time of capturing boulders and the like is transmitted to the foundation concrete 107 and the embankments 105 on both sides via the support columns 111 and the cross beams 115 and resists. There is a risk that it can only be transmitted to the body 5 and the boulders cannot be captured sufficiently.

  As a technical means for solving this, the end portion 115a of the transverse beam 115 is filled in the sheath tube 119 by filling a gap 120 between the end portion 115a of the transverse beam 115 and the sheath tube 119 with a curable filler such as mortar. On the other hand, it is conceivable that the bending moment of the base portion 111a of the support column 111 generated when capturing boulders or the like is firmly fixed. However, if the end portion 115a of the cross beam 115 is fixed in this way, the gap 120 as a margin for the end portion 115a of the cross beam 115 to move relative to the sheath tube 119 disappears, and the temperature changes. Due to this, when the concrete and steel materials expand and contract, temperature stress is generated. Further, in this case, it becomes difficult to disassemble the cross beam 115 into a plurality of steel pipes during the repair work and extract the end portion 115a of the cross beam 115 from the sheath pipe 119, leading to a reduction in workability during the repair work.

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is a steel slit dam having a structure in which an end portion of a transverse beam is inserted into a sheath tube, and a steel material due to temperature change. Steel slit dam, its construction method and repair, which can reduce the bending moment acting on the strut at the time of collision with boulders, etc. while exhibiting the function of absorbing the expansion and contraction of concrete and preventing the generation of temperature stress It is to provide a method.

  In order to solve the above-mentioned problems, the inventor has invented the following steel slit dam, its construction method, and repair method after intensive studies.

  A steel slit dam according to a first aspect of the present invention includes a column erected between concrete dam bodies constructed at intervals in the river width direction of a river, a sheath pipe embedded in the dam body, an end In a steel slit dam having a transverse beam inserted into the sheath pipe and spanned between the dam bodies and connected to the support column, a downstream outer peripheral surface of the transverse beam and a downstream inner peripheral surface of the sheath pipe And a gap maintaining member interposed so as to be inserted and removed from the opening of the sheath tube.

  A steel slit dam according to a second invention further comprises a positioning member fixed to a downstream inner peripheral surface of the sheath tube in the first invention, and the spacing member is at least the positioning member in the gap. It is characterized by being interposed by being supported by a member.

  A steel slit dam according to a third aspect of the present invention is the second aspect of the invention, further comprising a pair of upper and lower positioning members fixed to the inner peripheral surface on the downstream side of the sheath tube, wherein the spacing member is the pair of upper and lower parts. It is characterized by being interposed between positioning members.

  In a steel slit dam according to a fourth invention, in any one of the first to third inventions, the spacing member is covered with an elastic sealing material filled in a gap between the transverse beam and the sheath tube. It is characterized by being inserted in the state of being.

  The steel slit dam according to a fifth invention is the steel slit dam according to any one of the first to fourth inventions, wherein the spacing member is at least two above and below sandwiching a horizontal plane passing through the axis of the sheath tube. It is characterized by being interposed.

  The construction method of the steel slit dam according to the sixth invention is the construction method of the steel slit dam according to any one of the first to fifth inventions, wherein the end portion of the transverse beam is inserted into the sheath tube. After that, a spacing member is interposed in a gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube.

  According to a seventh aspect of the present invention, there is provided a method for constructing a steel slit dam according to the sixth aspect, wherein an end beam member constituting a part of the horizontal beam is inserted into the sheath tube and connected to the column. After connecting the end beam member to the intermediate beam member constituting the section, a spacing member is interposed in the gap between the downstream outer peripheral surface of the end beam member and the downstream inner peripheral surface of the sheath tube. It is characterized by that.

  The construction method of the steel slit dam according to the eighth invention is the construction of the sixth or seventh invention, wherein the downstream outer peripheral surface of the transverse beam and the sheath tube are formed from a plurality of spacing members of different thicknesses prepared in advance. An interval holding member having a thickness corresponding to the radial length of the gap with the downstream inner peripheral surface is interposed.

  The steel slit dam repair method according to the ninth invention is a steel slit dam repair method for repairing the damaged beam end of the steel slit dam according to any one of the first to fifth inventions. The existing spacing member is extracted from the sheath tube, the end of the existing cross beam is extracted from the sheath tube, and the end of the new cross beam is inserted into the sheath tube, and then the outer periphery on the downstream side of the cross beam. A spacing member is interposed in the gap between the surface and the downstream inner peripheral surface of the sheath tube.

  A steel slit dam repair method according to a tenth aspect of the present invention is the ninth aspect of the present invention, in which the existing interval holding member is extracted from the sheath tube and part of the transverse beam connected to the support column is formed. Remove the existing end beam member that constitutes a part of the transverse beam from the beam member, extract it from the sheath tube, insert the new end beam member into the sheath tube, and insert the end beam member into the intermediate beam member After connecting the beam member, a spacing member is interposed in a gap between the downstream outer peripheral surface of the end beam member and the downstream inner peripheral surface of the sheath tube.

  A repair method for a steel slit dam according to an eleventh aspect of the invention is the ninth or tenth aspect of the invention, in which the downstream outer peripheral surface of the transverse beam and the downstream side of the sheath pipe are separated from a spacing member having different thicknesses prepared in advance. An interval holding member having a thickness corresponding to the radial length of the gap with the inner peripheral surface is interposed.

  According to the first invention, since the spacing member is interposed in the gap between the downstream outer peripheral surface of the horizontal beam and the downstream inner peripheral surface of the sheath tube, the amount of displacement of the end portion of the horizontal beam to the downstream side is reduced. This makes it possible to reduce the bending moment acting on the base portion of the column. In addition, according to the present invention, since the end portion of the cross beam is not firmly fixed to the sheath tube, the expansion and contraction can be absorbed when the steel material and concrete expand and contract due to temperature change. In addition, according to the present invention, it is possible to absorb construction errors and the like by not interposing the spacing members when assembling the columns and cross beams, and by installing the spacing members after assembly, etc. The effect of making it possible to absorb the expansion and contraction of a steel material or the like due to a temperature change while suppressing the bending moment acting on the steel can be exhibited.

  According to the third aspect of the invention, the upper and lower positioning members function as a guide for guiding the spacing member to be accurately inserted at a predetermined position, and the upper spacing member collides with a boulder or the like. At this time, the function of preventing the interval holding member from floating and falling off from the lower interval holding member is exhibited, and the workability and the structural reliability are improved.

  According to the fourth aspect of the present invention, it is possible to almost certainly prevent the gap holding member from moving and falling off while preventing corrosion of the end portions of the sheath tube and the transverse beam due to water entering the sheath tube by the elastic sealing material. Is possible.

  According to the fifth aspect, it is possible to stably exhibit the effect of reducing the amount of displacement of the end portion of the cross beam toward the downstream side.

It is a perspective view which shows the structure of the steel slit dam which concerns on this invention. It is front sectional drawing which shows the structure of the steel slit dam which concerns on this invention. It is an enlarged view of S1 part in FIG. It is the sectional view on the AA line in FIG. (A) is an enlarged view of S2 part in FIG. 4, (b) is an enlarged view of S3 part in FIG. It is a disassembled perspective view which shows the state before providing a space | interval holding member and a cross beam in a sheath pipe. It is front sectional drawing for demonstrating an example of the construction method of the steel slit dam which concerns on this invention. It is the elements on larger scale for demonstrating an example of the construction method of the steel slit dam which concerns on this invention. It is sectional drawing for demonstrating the procedure at the time of inserting a space | interval holding member in a sheath pipe in the construction method of the steel slit dam which concerns on this invention. It is front sectional drawing for demonstrating the repair method of the steel slit dam which concerns on this invention. (A) is front sectional drawing which shows 2nd Embodiment of the steel slit dam which concerns on this invention, (b) is BB sectional drawing of (a). It is sectional drawing which shows 3rd Embodiment of the steel slit dam which concerns on this invention. It is a perspective view which shows the structure of the conventional steel slit dam. It is sectional drawing which shows the structure of the cross beam in a sheath pipe in the conventional steel slit dam. It is the side view which modeled the structure of the conventional steel slit dam.

  Hereinafter, as a form for carrying out the present invention, a steel slit dam applied to a river or the like, a construction method thereof, and a repair method will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a configuration of a steel slit dam 1 according to the present invention, FIG. 2 is a front sectional view thereof, and FIG. 3 is an enlarged view of a portion S1 in FIG.

  The steel slit dam 1 to which the present invention is applied is applied to a river 3 as shown in FIGS. 1 and 2, for example. In this river 3, foundation concrete 7 is constructed on the river bed 4, and a plurality of concrete dam bodies 5 are constructed at intervals in the river width direction. In the river 3, water flows from the upstream side to the downstream side in the flow path 3 a formed by being surrounded by the plurality of levee bodies 5 and the foundation concrete 7.

  A steel slit dam 1 to which the present invention is applied includes a column 11 erected between a plurality of dam bodies 5, a sheath pipe 19 embedded in the dam body 5, and end portions 15a on both sides within the sheath pipe 19. And a horizontal beam 15 which is installed between the plurality of dam bodies 5 and connected to the support column 11.

  A plurality of pillars 11 are provided substantially vertically at intervals in the river width direction of the river 3. Each support | pillar 11 is comprised by the some pillar members 12 and 13 which consist of steel pipes etc., for example, and one support | pillar 11 is the base part pillar member 12 embed | buried in the foundation concrete 7 in this embodiment. The intermediate portion column member 13 is connected to the base portion column member 12 and the cross beam 15 on both upper and lower sides. In the present embodiment, three struts 11 are erected in the river width direction of the river 3.

  A plurality of horizontal beams 15 are installed substantially horizontally at intervals in the height direction. Each transverse beam 15 is constituted by a plurality of beam members 16 and 17 made of, for example, steel pipes, and one transverse beam 15 is an end portion inserted into the sheath tube 19 on both sides in the river width direction in this embodiment. It consists of a beam member 16 and an intermediate beam member 17 whose left and right sides are connected to two end beam members 16 spaced in the river width direction. In the present embodiment, two horizontal beams 15 are installed in the height direction.

  The two intermediate beam members 17 in this embodiment are provided with a plurality of branch pipes 17a that are branched on one or both sides of the upper and lower sides so as to intersect in a T shape or a cross shape. Each intermediate column member 13 constituting the column 11 is connected to the branch pipe 17 a of the intermediate beam member 17.

  Each column member 12 and 13, the beam members 16 and 17, and the branch pipe 17a which consist of the steel pipe which comprises the support | pillar 11 and the cross beam 15 have the flange 18 attached to the one end or both ends, and connect the flange 18 mutually. The flanges 18 of the other members are brought into contact with the flanges 18 and bolted to the flanges 18 so as to be detachably connected to each other. In addition, as a connection method between the members constituting the support column 11 and the cross beam 15, any method using the flange 18 may be applied, or connection may be performed by welding or the like without forming the flange 18. From the viewpoint of facilitating construction work and repair work of the steel slit dam 1, it is preferable to apply a method of detachably connecting by bolt joining.

  The support column 11 and the cross beam 15 are connected so as to form a lattice-like structure, and thereby configured to be able to capture boulders, driftwood, and the like flowing in the river 3.

  4 is a cross-sectional view taken along line AA in FIG. 5A is an enlarged view of a portion S2 in FIG. 4, and FIG. 5B is an enlarged view of a portion S3 in FIG. FIG. 6 is an exploded perspective view showing a state before the spacing member 21 and the cross beam 15 are provided in the sheath tube 19.

  As shown in FIGS. 3 and 4, the steel slit dam 1 according to the present invention is disposed in a gap 20 between the downstream outer peripheral surface 15 b of the cross beam 15 and the downstream inner peripheral surface 19 b of the sheath tube 19. The holding member 21 and a pair of upper and lower positioning members 23 and 24 fixed to the downstream inner peripheral surface 19b of the sheath tube 19 are further provided.

  The sheath pipe 19 is embedded in the bank body 5 so as to be opened toward the flow path 3a between the bank bodies 5, and is made of, for example, a steel pipe. The end portion 15a of the cross beam 15 is inserted inside the sheath tube 19, and in this embodiment, the end beam member 16 constituting a part of the cross beam 15 is inserted. The cross beam 15 into which the end portion 15a is inserted into the sheath tube 19 is supported by the column 11, and is not in contact with the sheath tube 19 in the radial direction or the axial direction as shown in FIGS. Or you may contact in part.

  The spacing member 21 holds the spacing so that the spacing of the end 15a of the transverse beam 15 relative to the sheath tube 19 is not displaced too much when the transverse beam 15 is about to be displaced downstream by capturing boulders or the like. For the purpose. The spacing member 21 is composed of, for example, a steel member obtained by cutting a steel plate into a rectangular parallelepiped shape. However, the material is not particularly limited as long as a certain degree of strength and rigidity can be secured. You may be comprised from a ferrous metal, a nonferrous metal, a plastic, hard rubber, wood, etc. Further, the cross-sectional shape of the spacing member 21 is not particularly limited.

Further, since the spacing member 21 transmits a load such as a static load or an impact load on the cross beam 15 generated when capturing boulders or the like to the dam body 5 via the spacing member 21, the spacing member 21 is downstream from the cross beam 15. In order to prevent buckling earlier than the lateral beam 15 when a load is applied toward the side, it is preferable that the compressive strength is equal to or higher than the compressive strength of the lateral beam 15. For example, when the cross beam 15 is made of a steel material having a compressive strength of 200 N / mm ² , the spacing member 21 may be made of a steel material having the same degree as this compressive strength.

  The lower positioning member 23 of the pair of upper and lower positioning members 23, 24 prevents the interval holding member 21 placed thereon from falling between the sheath tube 19 and the cross beam 15, thereby holding the interval. The member 21 is fixed so as to be interposed at a predetermined position. The spacing member 21 is interposed by being supported by the positioning member 23, the sheath tube 19, or the cross beam 15.

  In the present embodiment, two spacing members 21 are interposed in one sheath tube 19, but this support mode will be described with reference to the example of the drawing. The spacing member 21 on the upper side is shown in FIG. ), The lower positioning member 23 and the cross beam 15 are engaged with each other and supported so as not to fall down between the positioning member 23 and the cross beam 15. Further, as shown in FIG. 5 (b), the lower spacing member 21 is engaged with the lower positioning member 23 and the sheath tube 19, and falls down from between the positioning member 23 and the cross beam 15. It is supported not to. As described above, the spacing member 21 only needs to be interposed by being supported by at least the positioning member 23.

  The spacing member 21 supported by the lower positioning member 23 is in a state of being supported with respect to the positioning member 23 and is interposed in a state where it can be inserted and removed from the opening 19 a of the sheath tube 19. . The position in the axial direction in the sheath tube 19 in which the spacing member 21 is interposed is close to the opening 19a in the sheath tube 19 as shown in FIG. Although it is preferable to be interposed, it is not limited to this.

  The axial length of the spacing member 21 is not particularly limited, but if it is too short, the position thereof is not stable, and if it is too long, the end beam member 16 and the intermediate beam member 17 are connected. It becomes difficult to insert and remove from the opening 19a of the sheath tube 19 because the flange 18 is obstructed. For this reason, the axial length of the spacing member 21 may be appropriately set in consideration of this, and is preferably about 50 to 100 mm, for example. In the present embodiment, the axial length of the sheath tube 19 is about 1900 mm, and the axial length of the spacing member 21 is about 100 mm.

  The upper positioning member 24 guides the spacing member 21 together with the lower positioning member 23 so that the spacing member 21 is accurately inserted at a predetermined position when the spacing member 21 is inserted into and removed from the opening 19a of the sheath tube 19. The interval holding member 21 is interposed between a pair of upper and lower positioning members 23 and 24. Further, when the boulder or the like collides with the support column 11 or the cross beam 15 and the impact load is transmitted to the interval holding member 21, the upper positioning member 24 floats and falls off the lower positioning member 23. It also has a function to prevent this. Thus, by providing the upper positioning member 24, it is possible to improve the workability and the structural reliability. However, it is not essential to provide this, and only the lower positioning member 23 may be provided.

  As shown in FIGS. 3 and 6, a stopper member 25 is fixed to the sheath tube 19 on the back side of the sheath tube 19 with respect to the pair of upper and lower positioning members 23 and 24. The stopper member 25 is composed of a plate-like member or the like. When the interval holding member 21 is inserted between the pair of positioning members 23 and 24, the stopper member 25 comes into contact with the inserted interval holding member 21 and the back of the sheath tube 19. It is intended to prevent excessive insertion into the side. Providing the stopper member 25 is not essential.

  The pair of upper and lower positioning members 23 and 24 and the stopper member 25 are, for example, fixed by welding a steel plate-like member as in the present embodiment to the sheath tube 19, but its cross-sectional shape The material and the fixing method are not particularly limited.

  The pair of upper and lower positioning members 23 and 24 and the stopper member 25 correspond to the number of spacing members 21 to be interposed in the gap 20 between the downstream outer peripheral surface of the cross beam 15 and the downstream inner peripheral surface 19b of the sheath tube 19. It is sufficient that the sheath tube 19 is fixed to the number of the sheath tube 19, and the sheath tube 19 may be fixed from the previous stage of transporting the sheath tube 19 to the construction site, or may be fixed on the construction site.

  When boulders and driftwood flowing from the upstream side to the downstream side of the river 3 are captured by the struts 11 and the cross beams 15 of the steel slit dam 1 according to the present invention having such a configuration, static loads and impacts from the boulders etc. A load such as a load is transmitted to the foundation concrete 7 and the dam bodies 5 on both sides via the support 11 and the cross beam 15 to resist the load. In this case, the horizontal beam 15 tends to move downstream until a load from a boulder or the like can be transmitted to the levee body 5 through the sheath pipe 19.

  Here, in the steel slit dam 1 according to the present invention, the spacing member 21 is interposed in the gap 20 between the downstream outer peripheral surface 15b of the cross beam 15 and the downstream inner peripheral surface 19b of the sheath tube 19, It is possible to reduce the amount of displacement of the end portion 15a of the cross beam 15 to the downstream side, thereby reducing the amount of displacement of the column 11 connected to the cross beam 15 to the downstream side. It has become. For this reason, the bending moment which acts on the base part 11a etc. of the support | pillar 11 can also be suppressed, As a result, even when a boulder etc. are captured, the possibility that the support | pillar 11 yields can be reduced significantly.

  Further, the steel slit dam 1 according to the present invention is spaced from the gap 20 between the transverse beam 15 and the sheath tube 19 to the gap 20 between the downstream outer peripheral surface 15b of the transverse beam 15 and the downstream inner peripheral surface 19b of the sheath tube 19. Since the holding member 21 is interposed and the end portion 15a of the cross beam 15 is not firmly fixed to the sheath tube 19, when the steel material or concrete expands or contracts due to temperature change, for example, upstream of the cross beam 15 This expansion / contraction is performed by a gap 26 between the side outer peripheral surface 15c and the upstream inner peripheral surface 19c of the sheath tube 19, a gap 28 between the axial end portion 15d of the cross beam 15 and the rear end portion 19d of the sheath tube 19, or the like. Can be absorbed. For this reason, while suppressing the bending moment which acts on the base part 11a etc. of the support | pillar 11, it is possible to exhibit the function which absorbs the expansion-contraction of the steel materials and concrete by a temperature change, and prevents generation | occurrence | production of a temperature stress. .

  In addition, the number of the interval holding members 21 interposed per one sheath tube 19 is not particularly limited, and only one may be interposed. Further, when two or more spacing members 21 are interposed, as shown in FIG. 4, the gap between the end portion 15 a of the cross beam 15 and the sheath tube 19 is formed in the sheath tube 19 for the reason described below. It is preferable that at least one piece is interposed above and below the virtual horizontal plane P1 passing through the axis G.

  When boulders or the like collide with the cross beam 15 inserted in the sheath tube 19, these boulders or the like collide with the cross beam 15 from various positions on the upstream side. For this reason, when a collision load is applied due to a collision with a boulder or the like, the end portions 15a of the cross beam 15 are not only in the horizontal direction toward the downstream side but also in various directions toward the downstream side inclined up and down with respect to the horizontal plane. An attempt is made to move within the sheath tube 19. Here, if the two spacing members 21 are interposed under the above-described conditions, the effect of reducing the amount of displacement of the end portion 15a of the cross beam 15 that is going to move in various directions toward the downstream side is achieved. It becomes possible to demonstrate stably.

  In addition, the spacing member 21 defines, as inclined planes P2 and P3, virtual planes that are inclined at 45 ° upward and downward with respect to the horizontal plane P1 passing through the axis G of the sheath tube 19 around the axis G. In such a case, it is preferable to be interposed so as to be included in the range between the inclined surfaces P2 and P3. If the spacing member 21 is interposed at a position that exceeds this range, the amount of displacement of the end 15a of the cross beam 15 that attempts to move in various directions toward the downstream side as described above can be stably reduced. This is because it becomes difficult to exert the effect.

  Further, as shown in FIG. 5, the gap holding member 21 in the present invention may have a gap 27 between the gap holding member 21 and the cross beam 15 or the sheath tube 19, but the gap 27 may be small. The smaller it is, the more preferable it is possible to suppress the downstream displacement of the end 15a of the cross beam 15. Of course, the clearance 27 may be adjusted to be zero.

  The radial length L1 of the gap 27 is the displacement of the column 11 connected to the horizontal beam 15 when the end 15a of the horizontal beam 15 is to be displaced downstream in the sheath pipe 19 by capturing boulders and the like. It is sufficient that the amount is adjusted to be within the elastic range. The radial length L1 of the gap 27 is preferably adjusted to be, for example, 3 mm or less, so that the base 11a and the like of the column 11 can be stably stabilized regardless of the size and strength of the column 11 and the cross beam 15. It is possible to prevent surrender. This is based on experimental findings made by the present inventors.

  In adjusting the radial length L1 of the gap 27, when the steel slit dam 1 is constructed and repaired, a plurality of spacing members 21 having different thicknesses at a predetermined pitch such as 3 mm pitch are provided. It is preferable to prepare in advance. Accordingly, the radial length of the gap 20 between the sheath tube 19 and the end portion 15a of the cross beam 15 formed after the end portion 15a of the cross beam 15 is inserted into the sheath tube 19 from the plurality of spacing members 21. Correspondingly, by interposing a gap holding member 21 that is closest to the radial direction length of the gap 20 and is thinner than this, the radial length L1 of the gap 27 is always kept below a certain value such as 3 mm or less. It becomes possible to suppress.

  In addition, when boulders and the like are captured by a plurality of horizontal beams 15 installed in the height direction, the horizontal displacement amount has the greatest influence on the bending moment of the base portion 11a of the support column 11 because a plurality of installed beams are installed. It becomes the horizontal beam 15 in the lowest position among the horizontal beams 15 that are present. That is, if it is assumed that only each of the plurality of transverse beams 15 is displaced by a certain amount in the horizontal direction, the inclination angle with respect to the vertical surface of the column 11 becomes larger as the one assumed to be displaced becomes lower, The bending moment acting on the root portion 11a of the column 11 is increased. For this reason, the spacing member 21 is interposed only between the end portion 15a of the cross beam 15 on the low position side in the height direction and the sheath tube 19, and the end portion of the cross beam 15 on the high position side in the height direction. The spacing member 21 may not be interposed between 15a and the sheath tube 19. As a result, it is possible to reduce the number of members and the number of work steps required for interposing the interval holding member 21, thereby reducing the construction cost and the construction period.

  Further, the lower positioning member 23 may not be provided as long as the state in which the interval holding member 21 is interposed at a predetermined position can be held.

  Next, an example of a construction method of the steel slit dam 1 having such a configuration will be described. FIG. 7 is a front sectional view for explaining the procedure of this construction method, FIG. 8 is a partially enlarged view for explaining the procedure of this construction method, and FIG. It is sectional drawing for demonstrating the procedure at the time of interposing.

  First, in the site where the steel slit dam 1 is to be constructed, the floor moat and leveling of the river bed 4 are performed, and then the concrete is placed on the river bed 4 as shown in FIG. 7 (a). 7 and the bank 5 are constructed. When the foundation concrete 7 is constructed, the concrete is placed so that the foundation column member 12 constituting the column 11 is embedded in a predetermined position, and when the dam body 5 is constructed, the sheath pipe 19 is embedded in the predetermined position. Concrete is placed so that The order in which the foundation concrete 7 and the bank body 5 are constructed is not particularly limited. In constructing the levee body 5, a reinforced structure in which steel plates or the like are previously assembled in a cubic lattice shape is installed on the river bed 4 or the foundation concrete 7, and the sheath pipe 19 is supported on the reinforced structure. You may make it cast concrete in the state made to do.

  Subsequently, as shown in FIG. 7A, the end portion 15a of the cross beam 15 is inserted from the opening 19a into the sheath pipe 19 embedded in the constructed dyke body 5. In the present embodiment, the end beam member 16 constituting a part of the horizontal beam 15 is inserted into the sheath tube 19.

  Subsequently, as shown by a two-dot chain line in FIG. 7 (b), the intermediate column member 13 constituting a part of the column 11 and the intermediate beam member 17 constituting a part of the cross beam 15 are replaced with the base column member 12. Are connected in order, and the column 11 and the cross beam 15 are assembled. Here, the end beam member 16 is connected to the intermediate column member 13 after the intermediate column member 13 to be connected to the end beam member 16 is connected to the column 11, and until that time, In the meantime, the gap holding member 21 is not interposed and is placed in the sheath tube 19. As a result, even if there is a construction error or manufacturing error due to the foundation concrete 7, the column 11, the cross beam 15 or the like when the steel slit dam 1 is constructed, the margin for the space is increased by the amount that the spacing member 21 is not interposed. The gap is between the sheath tube 19 and the end 15a of the cross beam 15, and this gap absorbs these construction errors and the like, thereby improving the workability.

  After assembling the support column 11 and the cross beam 15, as shown in FIG. 8, the gap holding member 21 is inserted into the gap 20 between the end portion 15 a of the cross beam 15 and the sheath tube 19. In this case, since the gap 20 between the end portion 15a of the cross beam 15 and the sheath tube 19 is used to absorb construction errors and the like as described above, the end portion 15a of the cross beam 15 to the sheath tube 19 is not provided. Depending on the insertion state, the radial length varies as shown in FIGS. 4 and 9A to 9C. In addition, the range which the dashed-two dotted line T in FIG.9 (a)-FIG.9 (c) shows has shown the same position as the position of the cross beam 15 in FIG.

  For this reason, in order to exhibit the effect of the present invention stably regardless of the insertion state of the end portion 15a of the cross beam 15 into the sheath tube 19, the thickness differs at a predetermined pitch prepared in advance as described above. It is preferable to interpose the spacing members 21 having a thickness corresponding to the radial length of the gap 20 between the sheath tube 19 and the end 15a of the cross beam 15 from the plurality of spacing members 21. As a result, the radial length L1 of the gap 27 formed between the spacing member 21 and the cross beam 15 or the sheath tube 19 as shown in FIG. 5 can always be kept below a certain value.

  For example, as shown in FIG. 9A, when the horizontal beam 15 is inserted at a position downstream of the position of the horizontal beam 15 in FIG. 4, the thickness is smaller than that of the spacing member 21 in FIG. 9B, when the horizontal beam 15 is inserted at a position displaced upstream from the position of the horizontal beam 15 in FIG. 4, the thickness is larger than the spacing member 21 in FIG. What is necessary is just to use.

  In this way, the construction work of the steel slit dam 1 is completed by interposing the interval holding member 21 having a thickness as required for each of the plurality of sheath tubes 19.

  As shown in FIG. 9 (c), since there are a plurality of sheath pipes 19 for one steel slit dam 1, depending on the sheath pipe 19, the lateral beam 15 is located downstream of the position of the lateral beam 15 in FIG. There is a case where it is displaced so much that it is displaced to the extent that it contacts the positioning members 23, 24. In this case, since the end portion 15a of such a cross beam 15 cannot be greatly displaced downstream even when a boulder or the like is captured, the interval holding member 21 may not be interposed.

  According to the construction method of the steel slit dam 1 according to the present invention having such a configuration, the gap 20 between the sheath tube 19 and the end portion 15a of the cross beam 15 is maintained at the time of assembling the support column 11 and the cross beam 15. As a result of not interposing the member 21, it is possible to absorb the construction error and the like by the gap 20 even if there are construction errors and manufacturing errors due to the foundation concrete 7 and the columns 11. Further, after assembling the support column 11 and the cross beam 15, by inserting the gap holding member 21 into the gap 20 between the end 15 a of the cross beam 15 and the sheath tube 19, the steel material or the like caused by the temperature change as described above can be used. While exhibiting the function of absorbing expansion and contraction and preventing the generation of temperature stress, it is possible to exhibit the effect of suppressing the bending moment acting on the root portion 11a of the column 11 and the like.

  Next, an example of a repair method for the steel slit dam 1 according to the present invention will be described. FIG. 10 is a front sectional view for explaining the procedure of this repair method.

  By capturing boulders and the like with the pillars 11 and the cross beams 15 of the steel slit dam 1 according to the present invention, the column members 12 and 13 and the beam members 16 and 17 constituting the pillars 11 and the cross beams 15 may be damaged. . In this case, the damaged member is replaced. When the end 15a of the cross beam 15 inserted into the sheath tube 19 is damaged, the end 15a of the damaged cross beam 15 is replaced and repaired. In order to do this, it is necessary to extract the end 15a of the cross beam 15 from the sheath tube 19.

  At the time of repairing the end portion 15a of the horizontal beam 15, first, as shown in FIGS. 10 (a) and 10 (b), the existing spacing member 21 is extracted from the inside of the sheath tube 19, and from the inside of the sheath tube 19. The end 15a of the existing cross beam 15 is extracted. In this case, the existing spacing member 21 may be extracted first, or the end 15a of the existing cross beam 15 may be extracted first. The end portion 15a of the existing cross beam 15 is usually provided with a gap 26 between the upstream outer peripheral surface 15c thereof and the upstream inner peripheral surface 19c of the sheath tube 19, so It is possible to easily perform the operation of extracting the end 15a of the horizontal beam 15. In the present embodiment, as shown in FIG. 10A, after the existing spacing member 21 is extracted from the inside of the sheath tube 19, the existing end beam member 16A constituting a part of the cross beam 15 is placed in the middle. After removing from the beam member 17, the end beam member 16 </ b> A which is the end 15 a of the lateral beam 15 is extracted from the inside of the sheath tube 19 as shown in FIG. 10B.

  Subsequently, as shown in FIG. 10B, the end 15 a of the newly installed cross beam 15 is inserted into the sheath tube 19. In the present embodiment, the newly installed end beam member 16 </ b> B is inserted into the sheath tube 19.

  Subsequently, as shown in FIG. 10 (c), a spacing member 21 is inserted and interposed in a gap 20 between the downstream outer peripheral surface 15 b of the cross beam 15 and the downstream inner peripheral surface 19 b of the sheath tube 19. In the present embodiment, after the end beam member 16B is connected to the intermediate beam member 17, the spacing member 21 is interposed.

  Thus, according to the steel slit dam 1 according to the present invention, while exerting the effect of suppressing the bending moment acting on the root portion 11a and the like of the column 11 while preventing the generation of the temperature stress as described above. However, the end 15a of the cross beam 15 can be easily replaced even during the repair work of the end 15a of the cross beam 15, and the workability during the repair work is excellent.

  If members other than the end portion 15a of the cross beam 15 are damaged during repair work, the damaged other member may be replaced with the end portion 15a of the cross beam 15.

  Next, another embodiment of the steel slit dam 1 according to the present invention will be described.

  Fig.11 (a) is front sectional drawing which shows 2nd Embodiment of the steel slit dam 1 which concerns on this invention, FIG.11 (b) is BB sectional drawing of Fig.11 (a). In this embodiment, the gap between the cross beam 15 and the sheath tube 19 is filled with the elastic sealing material 31, and the spacing member 21 is in a state where a part of the axial direction is covered with the elastic sealing material 31. It is intervened.

  This elastic sealing material 31 is provided over the entire circumferential range of the gap between the sheath tube 19 and the lateral beam 15 in order to prevent corrosion of the sheath tube 19 and the end portion 15a of the lateral beam 15 due to water entering the sheath tube 19. It is to be filled. In addition, the interval holding member 21 is shifted from the position where the interval holding member 21 is interposed or dropped off when the elastic sealing material 31 covers about half of the axial length. Can be prevented almost certainly. In particular, even if the concrete or steel material expands or contracts due to temperature changes, the elastic sealing material 31 has elasticity, so that the end 15a of the cross beam 15 and the sheath tube 19 can move relative to each other. Yes, this expansion and contraction can be absorbed and the function of preventing the generation of temperature stress can be exhibited. In addition, the axial direction length in which the space | interval holding member 21 is covered with the elastic sealing material 31 is not specifically limited, The whole axial direction of the space | interval holding member 21 may be covered with the elastic sealing material 31.

  The elastic sealing material 31 may be any material as long as it can be easily removed at the time of repairing the end portion 15a of the cross beam 15, has elasticity even after curing, and is durable without deterioration due to paint. For example, it is desirable to use one-component or two-component compositions such as acrylic, silicon, urethane, polysulfide, and oily. Further, from the viewpoint of preventing corrosion, it is sufficient that at least the opening 19a of the sheath tube 19 is filled. The spacing member 21 embedded in the elastic seal material 31 can be easily inserted and removed from the opening 19a of the sheath tube 19 by cutting the elastic seal material 31 with a blade.

  FIG. 12 is a cross-sectional view showing a third embodiment of the steel slit dam 1 according to the present invention. The interval holding member 21 and the pair of upper and lower positioning members 23 and 24 in the present embodiment are made of steel bars having a circular cross section. Thus, the interval holding member 21 and the pair of upper and lower positioning members 23 and 24 are not particularly limited in cross-sectional shape.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the embodiment mentioned above showed only the example of actualization in implementing this invention, and these are the technical aspects of this invention. The range should not be construed as limiting.

  For example, if the pillar 11 and the cross beam 15 of the steel slit dam 1 according to the present invention have a lattice-like structure capable of capturing boulders and the like flowing in the river 3, the cross-sectional shape and size of the members constituting them, The number and arrangement mode are not particularly limited to the above-described embodiment. For this reason, each column member 12, 13 constituting the column 11 has a branch pipe branched to the left and right sides or one side so as to intersect the column members 12, 13 in a T shape or a cross shape. Further, it may be provided. In addition, the steel slit dam 1 forms a further lattice-like structure downstream of the river 3 than one lattice-like structure constituted by a plurality of support columns 11 and cross beams 15, and these are connected by other members. It may be configured as described.

  Moreover, two or more flow paths 3a are provided by constructing three or more embankments 5 at intervals in the river width direction, and the steel slit dam 1 as described above is constructed for each flow path 3a. It is good.

1: Steel slit dam 3: River 4: River bed 5: Embankment 7: Foundation concrete 11: Post 12: Foundation column member 13: Intermediate column member 15: Cross beam 16: End beam member 17: Intermediate beam member 18: flange 19: sheath tube 20: gap 21: spacing member 23: positioning member 24: positioning member 25: stopper member 31: elastic sealing material

Claims (11)

Columns erected between concrete dam bodies constructed at intervals in the river width direction of the river, a sheath pipe embedded in the dam body, and an end portion inserted into the scabbard and the dam body In a steel slit dam provided with a cross beam laid between and connected to the support column,
A steel slit dam characterized by comprising a spacing member interposed in the gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube so that it can be inserted and removed from the opening of the sheath tube. A positioning member fixed to the inner peripheral surface on the downstream side of the sheath tube,
The steel slit dam according to claim 1, wherein the spacing member is interposed in the gap by being supported by at least the positioning member. Further comprising a pair of upper and lower positioning members fixed to the inner peripheral surface on the downstream side of the sheath tube,
The steel slit dam according to claim 2, wherein the spacing member is interposed between the pair of upper and lower positioning members. The said space | interval holding member is interposed in the state covered with the elastic sealing material with which the gap | interval of the said horizontal beam and the said sheath pipe was filled, The any one of Claims 1-3 characterized by the above-mentioned. Steel slit dam. The steel slit according to any one of claims 1 to 4, wherein at least two of the spacing members are interposed in the upper and lower sides sandwiching a horizontal plane passing through the axis of the sheath tube. dam. A construction method of a steel slit dam according to any one of claims 1 to 5,
After inserting the end portion of the transverse beam into the sheath tube, a spacing member is interposed in the gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube. How to build a dam. After the end beam member constituting a part of the transverse beam is inserted into the sheath tube and the end beam member is connected to the intermediate beam member constituting the part of the transverse beam connected to the support column, the end beam member is The method for constructing a steel slit dam according to claim 6, wherein a spacing member is interposed in a gap between the downstream outer peripheral surface of the beam member and the downstream inner peripheral surface of the sheath tube. An interval holding member having a thickness corresponding to the radial length of the gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube is provided from a plurality of interval holding members of different thicknesses prepared in advance. A construction method of a steel slit dam according to claim 6 or 7. A repair method of a steel slit dam for repairing an end portion of a damaged transverse beam of the steel slit dam according to any one of claims 1 to 5,
Withdrawing the existing spacing member from the sheath tube, withdrawing the end of the existing cross beam from the sheath tube,
After inserting the end portion of the newly installed transverse beam into the sheath tube, a spacing member is interposed in the gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube. How to repair slit dams. The existing spacing member is extracted from the sheath tube, and the existing end beam member constituting a part of the transverse beam is removed from the existing intermediate beam member constituting the part of the transverse beam connected to the support column. Extract from the sheath,
After inserting a new end beam member into the sheath tube and connecting the end beam member to the intermediate beam member, a downstream outer peripheral surface of the end beam member and a downstream inner peripheral surface of the sheath tube A method for repairing a steel slit dam according to claim 9, wherein a gap holding member is interposed in the gap between the steel slit dam and the steel slit dam. An interval holding member having a thickness corresponding to the radial length of the gap between the downstream outer peripheral surface of the transverse beam and the downstream inner peripheral surface of the sheath tube is interposed from the interval holding members of different thicknesses prepared in advance. The repair method of the steel slit dam of Claim 9 or 10 characterized by these.

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