Dam structure and method for constructing the same

Abstract

To provide a technique capable of accurately and easily building a capturing body on an existing dam.SOLUTION: A construction method of a dam structure includes: attachment steps S11, S12 of, on the wall surface facing the upstream side of a dam to which a capturing body is connected in the direction of river flow, driving multiple anchor bolts at positions where the multiple column members of the capturing body, which are installed at predetermined intervals in the width direction of the river, are connected, attaching anchor plates to the anchor bolts so that all the anchor plates are substantially on the same plane at the positions and driving the multiple anchor bolts at the positions of the wall surface, where side beam members provided between the column members provided at both ends of the multiple column members and the wall surface are connected, and attaching the anchor plates to the anchor bolts so that all the anchor plates are substantially on the same plane at the positions; and connection steps S31, S32 of connecting the column members and the side beam members of the capturing body to the corresponding anchor plates.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a dam structure and a method for constructing a dam structure. [Background technology]

[0002] Dams are installed in rivers in mountainous areas to prevent landslides caused by typhoons and heavy rains (see, for example, Patent Document 1). Dams allow water to pass through while preventing rocks and driftwood contained in debris flows from passing through, and their walls act to weaken the force of debris flows and also to hold back rocks and driftwood.

[0003] In recent years, so-called permeable dams have been constructed, in which slits are formed in part of the dam and fence-like trapping bodies made of steel pipes or the like are installed in the slits to capture rocks and driftwood without blocking the passage of water (see, for example, Patent Document 2).

[0004] Furthermore, in order to reduce damage caused by landslides, attempts have been made to install new trapping bodies on the upstream wall surfaces of existing impermeable dams that do not have trapping bodies installed (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2-55566 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-63840 [Patent Document 3] Patent Publication No. 2021-085198 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the upstream wall surface of an existing dam where a new trap will be installed may have unevenness due to aging of the dam itself, or may have portions that are missing or deformed due to debris flows, etc. If the upstream wall surface is deformed, it may be difficult to accurately and reliably install the trap on the existing dam, so it is necessary to repair the deformed portions by leveling them out.

[0007] For example, as in Patent Document 3, a measure has been considered in which a steel formwork is installed on the upstream wall surface and concrete is poured into the formwork to construct an adjusted concrete section with a flat surface on the upstream wall surface of an existing dam. This measure involves waiting for the concrete to harden and then driving in anchor bolts after the adjusted concrete has been constructed, and considering subsequent processes, it was necessary to make the surface of the adjusted concrete accurately flat.

[0008] Therefore, the present invention has been made in consideration of the above problems, and aims to provide a technology that allows for accurate and easy construction of a capture body on an existing dam. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a construction method for constructing a dam structure by additionally installing a capture body on an existing impermeable dam having a water passage portion, the construction method comprising the steps of: driving a plurality of anchor bolts into a wall surface facing the upstream side of the dam to which the capture body is connected in the direction of river flow, at each position where a plurality of pillar members of the capture body are connected, the pillar members being provided at predetermined intervals in the width direction of the river; attaching anchor plates to the anchor bolts so that all of the anchor plates are substantially on the same plane at each of the positions; driving a plurality of anchor bolts into each position on the wall surface where beam members provided between pillar members provided at both ends of the plurality of pillar members are connected to the wall surface; attaching anchor plates to the anchor bolts so that all of the anchor plates are substantially on the same plane at each of the positions; and connecting the pillar members and beam members of the capture body to the corresponding anchor plates.

[0010] In addition, in one aspect of the construction method according to the present invention, the gap between the wall surface and the anchor plate may be adjusted by moving the anchor plate relative to the anchor bolt.

[0011] In one aspect of the construction method according to the present invention, a structural anchor bolt may be used as the anchor bolt.

[0012] In addition, one aspect of the construction method according to the present invention may further include a step of filling a gap between the anchor plate and the wall surface with non-shrinkage mortar.

[0013] In addition, one aspect of the construction method of the present invention may further include a step of pouring concrete into the connection portion between the anchor plate and one end of the column member and the beam member to construct a root wrapping portion on the wall surface.

[0014] In addition, in one aspect of the construction method of the present invention, base plates provided at one end of each of the column member and the beam member connected to the anchor plate via the anchor bolt may have holes through which the anchor bolts are inserted, and the fixed positions of the column member and the beam member relative to the wall surface may be adjusted via a gap between the inner surface of the holes and the outer surface of the anchor bolts.

[0015] In addition, in one aspect of the construction method of the present invention, the column member and the beam member may be connected to the anchor plate, the column member and the beam member having a base plate provided at one end that is connected to the anchor plate via the anchor bolt, and a plurality of rib plates provided on the base plate so as to sandwich each anchor bolt in the column member and the beam member, respectively. [Effects of the Invention]

[0016] According to the present invention, a trap can be constructed on an existing dam with high accuracy and ease. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a front view of a dam structure constructed by a first construction method according to the present invention, viewed from the upstream side. [Figure 2] 1 is a perspective view of a dam structure constructed by a first construction method according to the present invention, viewed from the upstream side. FIG. [Figure 3] FIG. 1 is a side view of a dam structure constructed by a first construction method according to the present invention. [Figure 4A] FIG. 10 is a perspective view of the fixing portion of the main body and the sleeve portion. [Figure 4B] FIG. 4 is a cross-sectional view taken along line IVB-IVB in FIG. [Figure 5A] FIG. 10 is a side view of a leg member of the pillar member. [Figure 5B] 10 is a partially enlarged view showing a connecting portion between the first leg portion and the second leg portion of the pillar member and the fixed portion. FIG. [Figure 5C] FIG. 4 is an enlarged cross-sectional view of a portion VC in FIG. 3. [Figure 6] FIG. 10 is a front view of the central upright member of the pillar member as seen from the upstream side. [Figure 7A] FIG. 10 is a front view of the upright end member of the pillar member as seen from the upstream side. [Figure 7B] FIG. 10 is a side view of the end upright member of the pillar member. [Figure 8A] 8 is an enlarged view of a portion VIIIA in FIG. 2, showing a side beam member. [Figure 8B] FIG. 10 is a plan view schematically showing a connecting portion between a side beam member and a fixing portion. [Figure 8C] FIG. 8 is an enlarged cross-sectional view of a portion VIIIC in FIG. 3. [Figure 9] 1 is a flow chart showing steps in a first construction method. [Figure 10A] FIG. 1 is a front view showing an existing dam with an anchor plate attached. [Figure 10B] 10A and 10B are diagrams illustrating the process of attaching an anchor plate to an existing dam. [Figure 11A] FIG. 10 is a view showing a state in which a leg member is connected to a fixing portion. [Figure 11B] FIG. 10 is a view showing a state in which a side beam member is connected to a fixing portion. [Figure 11C] FIG. 10 is a view showing a state in which an upright member is connected to a leg member. [Figure 12] This is a front view of a dam structure constructed using the second construction method, viewed from the upstream side. [Figure 13] FIG. 10 is a cross-sectional view of a dam structure constructed by a second construction method. [Figure 14] 10 is a flow chart showing steps in a second construction method. [Figure 15] FIG. 1 is a front view showing an existing dam with an anchor plate attached. [Figure 16A] FIG. 10 is a view showing a state in which the leg member is connected to the anchor plate. [Figure 16B] 10 is a view showing a state in which a side beam member is connected to an anchor plate. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in the following description, the drawings are schematic, and the dimensional relationships and ratios of elements may differ from the actual ones. The dimensional relationships and ratios may differ between the drawings.

[0019] <Configuration of dam structure> Fig. 1 is a front view of a dam structure 1 constructed by a first construction method according to the present invention, viewed from the upstream side. Fig. 2 is a perspective view of a dam structure 1 constructed by a first construction method according to the present invention, viewed from the upstream side. Fig. 3 is a side view of a dam structure 1 constructed by a first construction method according to the present invention. For ease of explanation, the width direction of the river is designated "W", the flow direction of the river is designated "F", and the height direction of the dam structure 1 is designated "H".

[0020] The dam structure 1 comprises a dam 2 and a capture body 3. The dam structure 1 according to the present invention is constructed by newly installing the capture body 3 on an existing impermeable dam installed in a river, thereby enhancing the capture function of capturing driftwood, rocks, and other objects (objects) in addition to sediment flowing from the upstream of the river.

[0021] (dam) The dam 2 has its bottom buried in the ground and is constructed to extend across the river in the width direction W. The dam 2 is constructed as an impermeable dam, and is constructed, for example, from concrete or soil cement. Note that in the dam 2, the upstream wall surfaces 211, 222 facing the upstream side of the river and the downstream wall surfaces 212, 223 facing the downstream side may be steel plate walls formed by connecting multiple steel segments, and the interiors of these may be filled with concrete or soil cement.

[0022] The dam 2 has a main body 21 and a pair of sleeves 22, with a water passage 23 formed between the pair of sleeves 22. The main body 21 is provided on the river bottom side of the dam 2 and is constructed at a predetermined height in the height direction H from the river ground so as to block sediment flowing from the upstream side. The main body 21 is connected to both banks of the river. The main body 21 is formed in a substantially trapezoidal shape in side view. An upstream wall surface 211 of the main body 21 facing the upstream side slopes downstream as it extends upward from the river bottom toward the sleeves 22. Furthermore, a downstream wall surface 212 of the main body 21 facing downstream slopes downstream as it extends upward from the river bottom toward the sleeves 22. The inclination angle of the upstream wall surface 211 is smaller than the inclination angle of the downstream wall surface 212. The upstream wall surface 211 and the downstream wall surface 212 of the main body 21 may extend vertically from the bottom of the river toward the sleeve portion 22.

[0023] A plurality of fixing portions 213 are formed on the upstream wall surface 211. In this embodiment, two rows of 12 fixing portions 213 are provided along the width direction W. One row of the fixing portions 213 is provided at a predetermined interval from the other row of the fixing portions 213 in the height direction H of the dam structure 1. Three fixing portions 213 at both ends of each row in the width direction W are provided in positions overlapping with the sleeve portions 22, and six fixing portions 213 are provided in positions overlapping with the water passage portions 23. Note that the number of fixing portions 213 is an example and can be changed as appropriate depending on the size of the dam structure 1, etc., and is not particularly limited.

[0024] Each sleeve 22 is provided on the main body 21. The sleeves 22 are provided connected to both banks of the river at intervals in the width direction W of the river. Each sleeve 22 has a top surface 221, an upstream wall surface 222, a downstream wall surface 223, and a side wall surface 224. The top surface 221 is a flat surface facing upward of the dam structure 1. The top surface 221 extends horizontally or approximately horizontally from both banks toward the water passage portion 23, and then extends diagonally downward toward the side wall surface 224 (described later) toward the main body 21.

[0025] Upstream wall surface 222 faces the upstream side of the river, is continuous with upstream wall surface 211 of main body 21, and extends vertically from upstream wall surface 211 of main body 21 toward top surface 221. Downstream wall surface 223 faces the downstream side of the river, is continuous with downstream wall surface 212 of main body 21, and extends vertically from downstream wall surface 212 toward top surface 221. Note that upstream wall surface 222 may be inclined downstream from main body 21 toward top surface 221, and downstream wall surface 223 may be inclined upstream from main body 21 toward top surface 221.

[0026] A fixing portion 225 is formed on the upstream wall surface 222 of each sleeve portion 22. In the width direction W, the fixing portion 225 is provided at a position overlapping with the fixing portions 213 of the main body 21 at each end.

[0027] The side wall surfaces 224 extend between the upstream wall surface 222 and the downstream wall surface 223 along the river flow direction F. The side wall surfaces 224 of each sleeve portion 22 face each other at a predetermined interval in the width direction W, and a water passage portion 23 is formed between the side wall surfaces 224. The side wall surfaces 224 extend from the main body 21 side toward the top surface 221, sloping away from each other.

[0028] The water passage section 23 is provided near the center of the dam 2 in the width direction W of the river. Specifically, the water passage section 23 is formed as a recess between the side wall surfaces 224 of the sleeve section 22 that extends from both banks of the river on which the dam structure 1 is constructed to the center of the river. The water passage section 23 is formed to collect water flowing from upstream near the center of the dam 2 and direct it downstream.

[0029] (Capture body) The capture body 3 has a plurality of pillar members 31 and side beam members (beam members) 33. The capture body 3 is a structure that captures objects flowing from upstream in the river and allows the flowing water to pass through. The capture body 3 is provided upstream of the main body 21 and sleeve 22 of the dam 2 so as to face the water passage section 23 in the flow direction F. The capture body 3 is provided along the extension direction of the dam 2, i.e., the width direction W of the river. The capture body 3 is constructed so that the length in the width direction W is longer than the width of the water passage section 23. Both ends of the capture body 3 in the width direction W are positioned so as to face at least the sleeve 22 of the dam 2. The capture body 3 is provided on the dam 2 so that at least a portion of it is located above the bottom surface of the water passage section 23 of the dam 2.

[0030] The capturing body 3 is fixed to the main body 21 and the sleeve portion 22 via fixing portions 213 and 225, respectively. Fig. 4A is a perspective view of fixing portions 213 and 225 of the main body 21 and the sleeve portion 22. Fig. 4B is an enlarged cross-sectional view showing portion IVB in Fig. 1.

[0031] Each fixing portion 213 is a portion that protrudes from the slope of the upstream wall surface 211, and is formed in a rectangular or approximately rectangular shape in plan view. One end of a pillar member 31 of the capture body 3, which will be described later, is fixed to the fixing portion 213. The fixing portion 213 has a mortar portion 214, an anchor plate 215 formed from a steel plate, and, for example, a structural anchor bolt 216.

[0032] The mortar portion 214 is formed of, for example, mortar, particularly non-shrinkage mortar. The surface of the mortar portion 214 facing the side opposite the upstream wall surface 211 is covered with an anchor plate 215. A surface 215a of the anchor plate 215 is parallel or approximately parallel to the upstream wall surface 211. The anchor plate 215 has holes 215b, through which anchor bolts 216 are inserted, spaced equally around its center point. The surfaces 215a of the anchor plates 215 in each fixing portion 213 are on or are included in substantially the same plane P in the width direction W.

[0033] Here, "substantially on the same plane or included in a plane" means that, assuming a virtual plane P that is parallel to an ideal upstream wall surface 211 with no unevenness, the virtual plane P and the surface 215a of the anchor plate 215 are flush to an extent including construction tolerances, and do not necessarily need to be perfectly aligned.

[0034] Anchor bolt 216 is driven into main body 21 to a predetermined depth perpendicular or approximately perpendicular to upstream wall surface 211, penetrates mortar portion 214, and is inserted into hole 215b of anchor plate 215. The free end side of anchor bolt 216 extends a predetermined length from anchor plate 215. The position of anchor bolt 216 in each fixing portion 213 is all the same (see FIG. 4A).

[0035] Each fixing portion 225 is a portion that protrudes from the upstream wall surface 222 and is formed in a rectangular or approximately rectangular shape in plan view. One end of a side beam member 33 of the capture body 3, which will be described later, is fixed to the fixing portion 225. The fixing portion 225 has a mortar portion 226, an anchor plate 227 formed from a steel plate, and, for example, a structural anchor bolt 228.

[0036] The mortar portion 226 is formed of, for example, mortar, particularly non-shrinkage mortar. The surface of the mortar portion 226 facing the side opposite the upstream wall surface 222 is covered with an anchor plate 227. A surface 227a of the anchor plate 227 is parallel or approximately parallel to the upstream wall surface 222. The anchor plate 227 has holes 227b at its four corners through which anchor bolts 228 are inserted. The surfaces 227a of the anchor plates 227 in each fixing portion 225 are on or included in substantially the same plane in the width direction W.

[0037] Here, "substantially on the same plane or included in the plane" means that, assuming a virtual plane parallel to an ideal upstream wall surface 222 with no unevenness, the virtual plane and the surface 227a of the anchor plate 215 are flush with each other to an extent including construction tolerances, and do not necessarily need to be perfectly aligned.

[0038] Anchor bolts 228 are driven perpendicularly or approximately perpendicularly to the upstream wall surface 222 to a predetermined depth into each sleeve portion 22, penetrate the mortar portion 226, and are inserted into holes 227b in the anchor plate 227. The free ends of the anchor bolts 228 extend a predetermined length from the anchor plate 227. The positions of the anchor bolts 228 in each fixing portion 225 are all the same (see FIG. 4A).

[0039] The pillar members 31 are mainly formed of steel pipes, and are fixed to the respective fixing portions 213 of the main body 21 (see FIG. 3). Specifically, one pillar member 31 is fixed to two of the two rows of fixing portions 213 that are at the same position in the width direction W. The pillar members 31 are provided at a predetermined interval from each other along the width direction W, and are also provided at a predetermined interval from the dam 2 in the flow direction F. The interval between adjacent pillar members 31 is preferably half the length of driftwood expected to flow down the river, or a length equivalent to twice the diameter of the largest gravel expected to flow down the river.

[0040] The pillar member 31 has a leg member 310 and an upright member 313. For ease of explanation, the central pillar member 31 in the width direction W of the river among the pillar members 31 will also be referred to as the central pillar member 31a, and the pillar members 31 at both ends will also be referred to as the end pillar members 31b (see Figures 1 and 2). When there is no need to particularly distinguish between the two, they will simply be referred to as "pillar member 31." The leg member 310 is formed in a bifurcated shape and has a first leg portion 311 and a second leg portion 312 that are manufactured integrally with each other.

[0041] Fig. 5A is a side view of the leg member 310 of the pole member 31. Fig. 5B is a partially enlarged view of the connecting portion between the first leg portion 311 and the second leg portion 312 of the pole member 31 and the fixing portion 213. Fig. 5C is an enlarged cross-sectional view of portion VC in Fig. 3. One end of the first leg portion 311 is fixed to the lower fixing portion 213 of the two rows of fixing portions 213 in the main body 21. The first leg portion 311 extends obliquely upward from the fixing portion 213 toward the upstream side. The first leg portion 311 extends in the height direction H of the dam structure 1 to a position at least facing the upstream wall surface 222 of the sleeve portion 22 or the water passage portion 23.

[0042] The first leg portion 311 has a base plate 311a at one end connected to the fixed portion 213. The base plate 311a is formed from a steel material that is circular or approximately circular in plan view. The outer periphery of the base plate 311a protrudes outward in an annular shape from the tubular portion of the first leg portion 311. The base plate 311a has four holes 311b formed at predetermined intervals in the circumferential direction. The inner diameter of the holes 311b is larger than the diameter of the anchor bolt 216, and when the anchor bolt 216 is inserted through the holes 311b, there is a gap between the inner periphery of the holes 311b and the outer periphery of the anchor bolt 216 that is large enough to absorb construction errors when connecting the first leg portion 311 to the fixed portion 213.

[0043] Anchor bolts 216 extend from the holes 311b in the base plate 311a of the first leg 311, and nuts N1 are fastened to the extending portions of the anchor bolts 216. As a result, the first leg 311 is connected to the anchor plate 215 and fixed to the main body 21 via the fixing parts 213.

[0044] The first leg 311 has eight rib plates 311c at its end on the base plate 311a side. The rib plates 311c are provided at equal intervals in the circumferential direction on the outer circumferential surface of the first leg 311 and are attached in an upright position to the tubular portion of the first leg 311 and the base plate 311a by, for example, welding.

[0045] The rib plate 311c is formed in the shape of a right triangle or approximately a right triangle, with the right angle portion provided to correspond to the transition portion between the tubular portion of the first leg 311 and the base plate 311a. One end of the hypotenuse of the rib plate 311c reaches the peripheral edge of the base plate 311a, and the other end is located in the tubular portion of the first leg 311, farther from the base plate 311a than the one end. Each of the four anchor bolts 216 is located between two of the rib plates 311c.

[0046] The other end of the first leg 311 extends vertically and has a flange plate 311d. The first leg 311 is connected to an upright member 313 (described later) via the flange plate 311d. The flange plate 311d has the same configuration as the base plate 311a, except that it does not have the rib plate 311c.

[0047] One end of the second leg 312 is fixed to the upper one of the two rows of fixing portions 213 on the main body 21. The second leg 312 extends obliquely upward from the fixing portion 213 toward the upstream side. The other end of the second leg 312 is integrally connected to the first leg 311. The first leg 311 and second leg 312 of the pillar member 31 are constructed in a generally λ-shape when viewed from the side.

[0048] If the second leg 312 is arranged so as to follow the slope of the riverbed on the upstream side, the force of the debris flow can be received along the axial direction of the second leg 312. This is preferable because the second leg 312 can reduce the force that tries to peel the capture body 3 off the upstream wall surface 211 of the main body 21.

[0049] The second leg portion 312 has a base plate 312a at one end connected to the fixed portion 213. The base plate 312a is formed from a steel material that is circular or approximately circular in plan view. The outer periphery of the base plate 312a protrudes outward in an annular shape from the tubular portion of the second leg portion 312. The base plate 312a has four holes 312b formed at predetermined intervals in the circumferential direction. The inner diameter of the holes 312b is larger than the diameter of the anchor bolt 216, and when the anchor bolt 216 is inserted through the holes 312b, there is a gap between the inner periphery of the holes 312b and the outer periphery of the anchor bolt 216 that is large enough to absorb construction errors when connecting the second leg portion 312 to the fixed portion 213.

[0050] Anchor bolts 216 extend from the holes 312b in the base plate 312a of the second leg 312, and nuts N1 are fastened to the extending portions of the anchor bolts 216. As a result, the second leg 312 is connected to the anchor plate 215 and fixed to the main body 21 via the fixing parts 213.

[0051] The second leg 312 has eight rib plates 312c at its end on the base plate 312a side. The rib plates 312c are provided at equal intervals in the circumferential direction on the outer circumferential surface of the first leg 311 and are attached in an upright position to the tubular portion of the second leg 312 and the base plate 312a by, for example, welding.

[0052] The rib plate 312c is formed in the shape of a right triangle or approximately a right triangle, with the right angle corresponding to the transition between the tubular portion of the second leg 312 and the base plate 312a. One end of the hypotenuse of the rib plate 312c reaches the periphery of the base plate 312a, and the other end is located in the tubular portion of the second leg 312, farther from the base plate 312a than the one end. Each of the four anchor bolts 216 is located between two of the rib plates 312c.

[0053] One end of the upright member 313 is connected to the flange plate 311d of the first leg 311. The upright member 313 is provided above the first leg 311, which extends at an angle toward the upstream side, so as to change the oblique extension direction of the pillar member 31 to a vertical direction. Of the upright members 313, the member connected to the central pillar member 31a is referred to as the central upright member 313a, and the member connected to the end pillar member 31b is referred to as the end upright member 313b. When there is no need to particularly distinguish between the two, they will simply be referred to as the "upright member 313."

[0054] 6 is a front view of the central upright member 313a of the pillar member 31 as seen from the upstream side. The central upright member 313a has an upright portion 314 and a pair of beam portions 315. The upright portion 314 is connected to the first leg portion 311 and extends in the vertical direction or approximately vertical direction. The upright portion 314 has a flange plate 314a that is connected to the flange plate 311d of the central pillar member 31a of the pillar member 31.

[0055] The central upright member 313a has a pair of beams 315. The pair of beams 315 extend from the upright portion 314, crossing the upright portion 314 and facing each other in the width direction W, on the side closer to the end opposite the end connected to the first leg portion 311. A base plate 315a is provided at the free end of each beam 315. The uprights 314 are connected to each other via flange plates 315a of the beams 315 of the central pillar member 313a adjacent to each other in the width direction W, and flange plates 317a of the end upright members 313b, which will be described later.

[0056] Fig. 7A is a front view of the end upright member 313b of the pillar member 31 as seen from the upstream side. Fig. 7B is a side view of the end upright member 313b of the pillar member 31 as seen from the side. Here, the end upright member 313b at the left end as seen from the upstream side will be described as an example. The end upright member 313b has an upright portion 316 and two beam portions 317, 318. The upright portion 316 is connected at one end to the first leg portion 311. The beam portions 317, 318 extend vertically or approximately vertically from the outer circumferential surface of the upright portion 316, forming right angles with each other.

[0057] When the upright portion 316 is connected to the first leg portion 311, the beam portion 317 extends in the width direction W, and the beam portion 318 extends in the flow direction F. Both beam portions 317, 318 have flange plates 317a, 318a, respectively. The beam portion 317 is connected to the beam portion 315 of the central upright member 313a via the flange plate 317a, and the beam portion 318 is connected to the side beam member 33 described below via the flange plate 318a. When the upright members 313 are connected to all the first leg portions 311, the beam portions 315, 317 of the upright members 313 adjacent in the width direction W are connected to each other to form a beam 32 facing the upstream side of the capture body 3 and extending in the width direction W (see FIGS. 1 and 2).

[0058] 8A is an enlarged view of the side beam member 33 by enlarging the portion VIIIA in FIG. 2. FIG. 8B is a plan view schematically showing the connecting portion between the side beam member 33 and the fixing portion 225. FIG. 8C is a cross-sectional view showing an enlarged portion VIIIC in FIG. 3. One end of the side beam member 33 is connected to the end column member 31b, and the other end is fixed to the sleeve portion 22 via the fixing portion 225. The side beam member 33 captures objects such as driftwood that go around the capturing body 3 from the side. The side beam member 33 has a beam portion 331 and two upright portions 332.

[0059] The beam portion 331 has a base plate 331a at one end connected to the fixed portion 225 and a flange plate 331b at one end connected to the beam portion 331 of the end column member 31b. The base plate 331a is formed of steel material and has a circular or approximately circular shape in a plan view. The outer periphery of the base plate 331a protrudes outward in an annular shape from the tubular portion of the beam portion 331. The base plate 331a has four holes 331d formed at predetermined intervals in the circumferential direction. The inner diameter of the holes 331d in the base plate 331a is larger than the diameter of the anchor bolts 228 (described later). When the anchor bolts 228 (described later) are inserted through the holes in the base plate 331a, there is a gap between the inner periphery of the holes 331d and the outer periphery of the anchor bolts 216 (described later) that is large enough to absorb construction errors when connecting the second leg portion 312 to the main body 21.

[0060] An anchor bolt 228 extends from each hole, and a nut N2 is fastened to the extending portion of the anchor bolt 228. As a result, the side beam member 33 is connected to the anchor plate 227 and fixed to the sleeve portion 22 via the fixing portion 225.

[0061] The side beam member 33 has eight rib plates 331c at the end on the base plate 331a side. The rib plates 331c are provided at equal intervals in the circumferential direction on the outer circumferential surface of the side beam member 33 and are attached to the tubular portion of the side beam member 33 and the base plate 331a by, for example, welding.

[0062] The rib plate 331c is formed in the shape of a right triangle or a nearly right triangle, with the right angle portion positioned to correspond to the transition between the tubular portion of the side beam member 33 and the base plate 331a. One end of the hypotenuse of the rib plate 331c is located on the periphery of the base plate 331a, and the other end is located in the tubular portion of the side beam member 33, farther from the base plate 331a than the one end. Each of the four anchor bolts 228 is located between two of the rib plates 331c. The flange plate 331b has the same configuration as the base plate 331a, except that it does not have the rib plate 331c.

[0063] The two upright portions 332 protrude in two directions (up and down) in the vertical or approximately vertical direction from the outer peripheral surface of the beam portion 331. The upright portions 332 are provided at a predetermined interval from each other along the extension direction of the beam portion 331 (flow direction F).

[0064] <First construction method> The steps of constructing a dam structure 1 by installing a capture body 3 on an existing impermeable dam 100 will be described below. Figure 9 is a flow chart showing the steps of a first construction method. The construction method for a dam structure 1 according to the present invention is a construction method for constructing a dam structure 1 by additionally installing a capture body 3 on an existing impermeable dam 100 having a water passage portion 23, and involves driving a plurality of anchor bolts 216 into a wall surface 211 facing the upstream side of the dam 100 to which the capture body 3 is connected in the river flow direction F, at positions where a plurality of pillar members 31 of the capture body 3 are connected, which are provided at predetermined intervals in the width direction W of the river, and attaching anchor plates 217 to the anchor bolts 216 so that all anchor plates 217 are on substantially the same plane P at each position. and driving a plurality of anchor bolts 228 into positions on the wall surface 222 to which side beam members 33 provided between the wall surface 222 and the pillar members 31b provided at both ends of the plurality of pillar members 31 are connected, and attaching anchor plates 227 to the anchor bolts 228 so that all of the anchor plates 227 are on substantially the same plane at each position; and connecting steps S31 and S32 to connect the pillar members 31 and side beam members 33 of the capture body 3 to the corresponding anchor plates 215, 227. A method for constructing the dam structure 1 according to the present invention will be specifically described below.

[0065] The upstream wall surfaces 211, 222 of the existing dam 100 may become uneven due to, for example, aging or deterioration. If the upstream wall surfaces 211, 222 are uneven, construction errors may occur in the pillar members 31 of the capture body 3 attached to the upstream wall surfaces 211, 222, making it difficult to accurately and reliably construct the capture body 3 on the existing dam 100.

[0066] Fig. 10A is a front view showing an existing dam 100 to which anchor plates 215, 227 are attached. Fig. 10B is a diagram illustrating the process of attaching the anchor plates 215, 227 to the existing dam 100. In the present invention, first, the anchor plates 215, 227 to which each pillar member 31 and side beam member 33 of the capture body 3 are connected are attached to the upstream wall surfaces 211, 222 (pillar anchor plate attaching step S11 and side beam member anchor plate attaching step S12). In this case, the anchor plates 215 for the pillar members 31 attached to the upstream wall surface 211 are attached to the upstream wall surface 211 so that, for example, all of the anchor plates 215 are on substantially the same plane P.

[0067] In the pillar anchor plate installation process S11, first, the upstream wall surface 211 is marked out to determine the fixing positions of the leg members 310 of the pillar member 31. Based on the marking out, four anchor bolts 216 are driven into each position of the upstream wall surface 211 of the main body 21 where the pillar member 31 will be installed. Next, nuts N3 (see FIG. 4B) are fastened to each of the four anchor bolts 216 to attach the anchor plate 215 to the anchor bolts 216. This operation is performed at each position where the pillar member 31 will be installed. Next, it is confirmed that all of the anchor plates 215 are on substantially the same plane P.

[0068] For example, if the anchor plate 215 at one position is located away from the upstream wall surface 211 (not on the same plane P) relative to the anchor plate 215 at another position, the position of the anchor plate 215 can be adjusted by adjusting the position of the nut N3 attached to the anchor bolt 216.

[0069] In the side beam member anchor plate attachment process S12, first, the upstream wall surface 211 is marked out to determine the fixing positions of the leg members 310 of the column member 31. Based on the marking out, four anchor bolts 228 are driven into the upstream wall surface 221 of each sleeve section 22 where the side beam members 33 will be installed. Next, nuts N4 (see FIG. 5) are fastened to each of the four anchor bolts 228 to attach the anchor plates 227 to the anchor bolts 228. Next, it is confirmed that all of the anchor plates 227 are on substantially the same plane.

[0070] For example, if the anchor plate 227 at one position is located away from the upstream wall surface 222 (is not on the same plane) as the anchor plate 227 at another position, the position of the anchor plate 227 can be adjusted by adjusting the position of the nut N4 attached to the anchor bolt 228.

[0071] The order in which the pillar anchor plate attaching step S11 and the side beam member anchor plate attaching step S12 are performed is not particularly limited.

[0072] Next, the gaps between the anchor plates 215, 227 and the upstream wall surfaces 211, 222 are filled with, for example, mortar, particularly non-shrink mortar (mortar filling step S21), to form the mortar portions 214, 226. Specifically, formwork (not shown) is installed around the anchor plates 215, 227, except for the top surface 221 of the sleeve portion 22, and mortar is poured into the formwork. The formwork is removed after the mortar has hardened. This forms the fixing portion 213 of the main body 21 and the fixing portion 225 of the sleeve portion 22 (fixing portion forming step S22).

[0073] FIG. 11A is a diagram showing a state in which the leg member 310 is connected to the fixing portion 213. FIG. 11B is a diagram showing a state in which the side beam member 33 is connected to the fixing portion 225. FIG. 12C is a diagram showing a state in which the upright member 313 is connected to the leg member 310. Next, the pillar member 31 and the side beam member 33 are connected to each fixing portion 213, 225 (pillar member connecting step S31 and side beam member connecting step S32). First, with the leg member 310 hoisted by a crane, anchor bolts 216 are inserted into holes 311b, 312b in the base plate 311a of the first leg portion 311 and the base plate 312a of the second leg portion 312, respectively. With the leg member 310 hoisted, a desired position and posture are determined, and nuts N1 are tightened onto the anchor bolts 216 protruding from each base plate 311a, 312a. As a result, the leg member 310 is connected to the fixing portion 213 .

[0074] The leg members 310 are connected to the fixed portion 213 alternately on the left and right sides from the center of the installation width of the capture body 3, with the central upright member 313a connected to each central pillar member 31a. Adjacent leg members 310 may also be connected to each other via two length-adjustable connecting members (not shown).

[0075] Next, the side beam member 33, suspended by a crane, is brought close to the position where the side beam member 33 is to be attached. The anchor bolts 228 protruding from the fixing parts 225 are inserted into the holes in the base plates 331a of the beam parts 331 of the side beam member 33, and nuts N2 are fastened to the anchor bolts 228 protruding from each base plate 331a. This connects the side beam member 33 to the fixing parts 225.

[0076] Next, the end upright member 313b is connected to the central upright member 313a and the side beam member 33. The end column member 31b and the central upright member 313a are connected to each other via their respective flange plates 317b and 315a. Furthermore, the side beam member 33 and the end upright member 313b are connected to each other via their respective flange plates 331b and 318a. Through the above steps, a dam structure 1 is constructed in which a capture body 3 is installed on an existing dam 100.

[0077] According to the above construction method, in order to attach the capture body 3 to the existing dam 100, fixing portions 213, 225 are provided on the upstream wall surface 211 of the main body 21 and the upstream wall surface 222 of the sleeve portion 22, respectively, so that the capture body 3 can be constructed accurately and easily even if the existing dam 100 is uneven.

[0078] According to the first construction method of the present invention, the anchor plates 215, 227 of the fixing portions 213, 225 are adjusted so as to be included in substantially the same plane, and attached to the anchor bolts 216, 228, respectively. As a result, even if the upstream wall surfaces 211, 222 of the existing dam 100 are uneven, the capture body 3 can be installed on the existing dam 100 without being adversely affected by the unevenness. By additionally forming the fixing portions 213, 225 on the upstream wall surfaces 211, 222 of the existing dam 100, there is no need to cut the existing dam 100 itself to form a flat portion.

[0079] Furthermore, since structural anchor bolts 216, 228 are used in the fixing parts 213, 225, they have greater resistance to external forces than, for example, installation anchor bolts, and there is no need to cover the connection parts between the fixing parts 213, 225 and the pillar member 31 with concrete.

[0080] Furthermore, in the fixing parts 213, 225, the mortar parts 214, 226 are formed from non-shrinking mortar, which can suppress expansion during hardening and shrinkage after hardening, ensuring the strength of the fixing parts 213, 225, and also providing excellent water resistance, making them less susceptible to deterioration over time.

[0081] Furthermore, rib plates 311c, 312c are erected on the first leg 311 and the second leg 312 of the pillar member 31 so as to sandwich the anchor bolts 216, 228, thereby increasing the strength of the fixing portions 213, 225 of the pillar member 31 and preventing direct collision of gravel and the like with the anchor bolts 216, 228.

[0082] <Second construction method> Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and includes all aspects encompassed by the concept and scope of the claims. Furthermore, the configurations of the above embodiments may be appropriately and selectively combined to achieve at least some of the above-described problems and advantages. For example, in the first construction method, fixing portions 213, 225 made of non-shrinkage mortar are provided at the positions where the column member 31 and the side beam member 33 are fixed, but root wrapping portions 213A, 225A made of concrete may also be formed.

[0083] Figure 12 is a front view of a dam structure 1A constructed by a second construction method according to the present invention, viewed from the upstream side. The following description focuses only on the differences from the dam structure 1. The dam structure 1A comprises a dam 2 and a capture body 3. The dam structure 1 is constructed by newly installing a capture body 3 on the dam 2 of an existing impermeable dam installed in a river, thereby enhancing the capture function of capturing driftwood, rocks, and other objects in addition to sediment flowing from the upstream of the river. The second construction method uses column members 31 and side beam members 33 that do not have rib plates 311c, 312c, and 331c.

[0084] The dam 2 has a main body 21, a pair of sleeves 22, and a water passage section 23. A concrete wrapped section 213A is formed on the upstream wall surface 211 of the main body 21. Fig. 13 is a cross-sectional view of a dam structure 1A constructed by the second construction method. The wrapped section 213A is formed in a rectangular or approximately rectangular shape in a plan view, and is provided beyond the pillar member 31 in the width direction W. In the height direction H, it is provided, for example, from the bottom surface of the water passage section 23 to a position slightly beyond the first leg section 311. Note that the wrapped section 213A may extend in the height direction H up to the installation surface of the river on which the dam structure 1A is to be installed.

[0085] One ends of the first leg portion 311 and the second leg portion 312 are embedded in the root wrapping portion 213A. Furthermore, anchor plates 215 and, for example, installation anchor bolts 216A are provided inside the root wrapping portion 213A at each position where the pillar member 31 is to be installed, and the first leg portion 311 and the second leg portion 312 are each connected to the corresponding anchor plate 215. Surfaces 215a of the anchor plates 215 are arranged to be on or included in substantially the same plane.

[0086] A root wrapping portion 225A is formed on the upstream wall surface 222 of each sleeve portion 22. The root wrapping portion 225A is made of concrete and is located at the same position as the column members 31 at both ends in the width direction W. Each root wrapping portion 225A is a portion that protrudes from the upstream wall surface 222 and is formed in a rectangular or approximately rectangular shape in a plan view. One end of a side beam member 33 is embedded in the root wrapping portion 225A. An anchor plate 227 and, for example, an anchor bolt 228A for installation are provided inside the root wrapping portion 225A, and the side beam member 33 is connected to the anchor plate 227. The surfaces 227a of the two anchor plates 227 are arranged to be on or included in substantially the same plane.

[0087] The following describes the steps of constructing a dam structure 1A with a trapping body 3 by installing the trapping body 3 on an existing impermeable dam 100. Fig. 14 is a flow chart showing the steps in the second construction method. Fig. 16 is a front view showing an existing dam with an anchor plate attached.

[0088] In the second construction method, first, the anchor plates 215, 227 to which each pillar member 31 and side beam member 33 of the capture body 3 is attached are attached to the upstream wall surfaces 211, 222. The anchor plates 215, 227 are attached to the upstream wall surfaces 211, 222 so that the anchor plates 215, 227 are aligned in the same plane (pillar anchor plate attaching step S11A and side beam member anchor plate attaching step S12A). In this case, the anchor plates 215 for the pillar members 31 attached to the upstream wall surface 211 are attached so that all of the anchor plates 215 are on substantially the same plane, for example.

[0089] In the pillar anchor plate installation process S11A, first, the upstream wall surface 211 is marked out to determine the fixing positions of the leg members 310 of the pillar member 31. Based on the marking out, four anchor bolts 216 are driven into each position of the upstream wall surface 211 of the main body 21 where the pillar member 31 will be installed. Next, nuts N3 are fastened to each of the four anchor bolts 216 to attach the anchor plate 215 to the anchor bolts 216. This operation is performed at each position where the pillar member 31 will be installed. Next, it is confirmed that all of the anchor plates 215 are on substantially the same plane.

[0090] For example, if the anchor plate 215 at one position is located away from the upstream wall surface 211 (not on the same plane P) relative to the anchor plate 215 at another position, the position of the anchor plate 215 can be adjusted by adjusting the position of the nut N3 attached to the anchor bolt 216.

[0091] In the side beam member anchor plate attachment process S12A, first, the upstream wall surface 211 is marked out to determine the fixing positions of the leg members 310 of the column members 31. Based on the marking out, four anchor bolts 228 are driven into the upstream wall surface 221 of each sleeve section 22 where the side beam members 33 will be installed. Next, nuts N4 are fastened to each of the four anchor bolts 228, and the anchor plates 227 are attached to the anchor bolts 228. Next, it is confirmed that all of the anchor plates 227 are on substantially the same plane.

[0092] For example, if the anchor plate 227 at one position is located away from the upstream wall surface 222 (is not on the same plane) as the anchor plate 227 at another position, the position of the anchor plate 227 can be adjusted by adjusting the position of the nut N4 attached to the anchor bolt 228.

[0093] The order in which the pillar anchor plate attaching step S11A and the side beam member anchor plate attaching step S12A are performed is not particularly limited.

[0094] Fig. 16A is a diagram showing a state in which the leg member 31 is connected to the anchor plate 215. Fig. 16B is a diagram showing a state in which the side beam member 33 is connected to the anchor plate 227. Next, the pillar member 31 and the side beam member 33 are connected to each anchor plate 215, 227 (pillar member connecting step S21A and side beam member connecting step S22A).

[0095] With the leg member 310 hoisted by the crane, anchor bolts 216 are inserted through holes 311b, 312b in the base plate 311a of the first leg portion 311 and the base plate 312a of the second leg portion 312. With the leg member 310 hoisted, a desired position and posture are determined, and nuts N1 are fastened to the anchor bolts 216 protruding from the base plates 311a, 312a. This connects the leg member 310 to the anchor plate 215.

[0096] The leg members 310 are connected to the anchor plate 215 alternately on the left and right sides from the center of the installation width of the capture body 3, with the central upright member 313a connected to each central pillar member 31a. In this case, the end upright member 313b is not connected to the end pillar member 31b. Adjacent leg members 310 may also be connected to each other via two length-adjustable connecting members (not shown).

[0097] Next, the side beam member 33, suspended by a crane, is brought close to the position where the side beam member 33 is to be attached. The anchor bolts 228 protruding from the anchor plate 227 are inserted into the holes in the base plates 331a of the beam portions 331 of the side beam member 33, and nuts N2 are fastened to the anchor bolts 228 protruding from each base plate 331a. This connects the side beam member 33 to the anchor plates 227.

[0098] Next, the end upright member 313b is connected to the central pillar member 31a and the side beam member 33. The central pillar member 31a and the end pillar member 31b are connected to each other via their respective base plates 317b and 315a. In addition, the side beam member 33 and the end upright member 313b are connected to each other via their respective base plates 331b and 318a.

[0099] Next, concrete is poured around the connection portions between each anchor plate 215, 227 and the pillar members 31 and side beam members 33 of the capture body 3 (concrete pouring step S31A) to form the root wrapping portion 213A (see FIGS. 12 and 13). Specifically, a formwork (not shown) is installed to surround all of the leg members 310 of the pillar members 31 in the width direction W and height direction H, excluding the top surface 221 of the sleeve portion 22, and concrete is poured into the formwork. The formwork is removed after the concrete has hardened. As a result, the connection portions between the pillar members 31 and side beam members 33 of the capture body 3 and the anchor plates 215, 227 are covered with the root wrapping portion 213A (root wrapping portion forming step S32A). Through the above steps, a dam structure 1A in which the capture body 3 is installed on the existing dam 100 is constructed.

[0100] The second construction method can achieve the same effects as the first construction method. Furthermore, according to the second construction method, in order to attach the capture body 3 to an existing dam 100, a root wrapping portion 213A in which one end of the pillar member 31 and one end of the side beam member 33 are buried is provided on each of the upstream wall surface 211 of the main body 21 and the upstream wall surface 222 of the sleeve portion 22. This can improve the integration of the main body 21, the pillar member 31, the sleeve portion 22, and the side beam member 33.

[0101] In addition, one end of the pillar member 31 and the side beam member 33 is buried in the root wrapping portion 213A, and the connecting portion with the anchor plates 215, 227 is within the root wrapping portion 213A, so that gravel and the like are prevented from directly colliding with the connecting portion.

[0102] In the second construction method, rib plates 311c and 312c may be provided on the first leg 311 and the second leg 312 of the pillar member 31, and a rib plate 331c may be provided on the side beam member 33. This can increase the durability of the capture body 3. [Explanation of symbols]

[0103] 1,1A···Dam structure 2. Dam 21... main body, 22... sleeve portion, 23... water passage portion 211, 222···Upstream wall surface (wall surface), 213, 225···Fixing portion, 213A, 225A···Root wrapping portion, 214, 226···Mortar portion, 215, 227···Anchor plate, 216, 216A, 228, 228A···Anchor bolt 3. Capture body 31 Column member, 32 Beam, 33 Side beam member (beam member) 100 Existing impermeable dam

Claims

1. an attachment process of driving a plurality of anchor bolts into a wall surface facing the upstream side of a dam to which a capture body is connected in the river flow direction at each position where a plurality of pillar members of the capture body, which are provided at predetermined intervals in the width direction of the river, are connected, and attaching anchor plates to the anchor bolts so that all of the anchor plates are on substantially the same plane at each of the positions, and driving a plurality of anchor bolts into each position of the wall surface where beam members provided between pillar members provided at both ends of the plurality of pillar members and the wall surface are connected, and attaching anchor plates to the anchor bolts so that all of the anchor plates are on substantially the same plane at each of the positions; a connecting step of connecting the pillar members and the beam members of the capture body to the corresponding anchor plates, respectively; Including, A method for constructing a dam structure, further comprising the step of filling a gap between the anchor plate and the wall surface with non-shrinkage mortar.

2. A method for constructing a dam structure as described in claim 1, characterized in that structural anchor bolts are used as the anchor bolts.

3. An installation process comprising driving a plurality of anchor bolts into a wall surface facing the upstream side of a dam to which a capture body is connected in the direction of river flow at each position where a plurality of pillar members of the capture body, which are arranged at predetermined intervals in the width direction of the river, are connected, and attaching anchor plates to the anchor bolts so that all anchor plates are substantially on the same plane at each of the positions, and driving a plurality of anchor bolts into each position on the wall surface where beam members arranged between pillar members arranged at both ends of the plurality of pillar members and the wall surface are connected, and attaching anchor plates to the anchor bolts so that all anchor plates are substantially on the same plane at each of the positions; a connecting step of connecting the pillar members and the beam members of the capture body to the corresponding anchor plates, respectively; Including, A method for constructing a dam structure, further comprising a step of pouring concrete into the connecting portion between the anchor plate and one end of the column member and the beam member to construct a root wrapping portion on the wall surface.

4. An installation process comprising driving a plurality of anchor bolts into a wall surface facing the upstream side of a dam to which a capture body is connected in the direction of river flow at each position where a plurality of pillar members of the capture body, which are arranged at predetermined intervals in the width direction of the river, are connected, and attaching anchor plates to the anchor bolts so that all anchor plates are substantially on the same plane at each of the positions, and driving a plurality of anchor bolts into each position on the wall surface where beam members arranged between pillar members arranged at both ends of the plurality of pillar members and the wall surface are connected, and attaching anchor plates to the anchor bolts so that all anchor plates are substantially on the same plane at each of the positions; a connecting step of connecting the pillar members and the beam members of the capture body to the corresponding anchor plates, respectively; Including, a base plate provided at one end of each of the column member and the beam member connected to the anchor plate via the anchor bolt, the base plate having a hole through which the anchor bolt is inserted, and the fixing positions of the column member and the beam member relative to the wall surface are adjusted via a gap between the inner surface of the hole and the outer surface of the anchor bolt.

5. A method for constructing a dam structure as described in any one of claims 1 to 4, characterized in that the gap between the wall surface and the anchor plate is adjusted by moving the anchor plate relative to the anchor bolt.

6. A method for constructing a dam structure as described in any one of claims 1 to 5, characterized in that the column members and beam members have a base plate provided at one end that is connected to the anchor plate via the anchor bolt, and a plurality of rib plates provided on the base plate so as to sandwich each anchor bolt in the column members and the beam members, respectively.

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