Sand control dam structure, and sand control dam construction method

Abstract

To provide a sand control dam structure and a sand control dam construction method applied to the existing sand control dam and capable of suppressing deterioration of the levee widening portion of the reconstructed sand control dam.SOLUTION: A sand control dam structure comprises: an existing dam 11; a support member 12 having one end connected to the existing dam 11; an external protective material 13 connected to the other end of the support member 12 and arranged to form a space between the external protective material and the existing dam 11; and a structure 15 disposed between the existing dam 11 and the external protective material 13, the structure 15 being formed from a flow-type sand control soil cement in which sand control soil cement material is generated by mixing cement milk with on-site generated soil or a base material obtained by mixing the on-site generated soil with at least one of crushed stone and steel slag as a modifier, and the sand control soil cement material is placed between the existing dam and the external protective material and solidified.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to a sabo dam structure and a sabo dam construction method that are constructed by attaching a new sabo dam to the embankment body of an existing sabo dam. [Background technology]

[0002] In recent years, rising temperatures have led to a trend of more frequent and severe landslides. In response to this situation, there is a demand for further strengthening of hard countermeasures such as the construction of sabo facilities, while at the same time, there is also a push to make effective use of existing stocks, and existing sabo facilities are being renovated by adding reinforcement so that they comply with current standards.

[0003] When renovating an existing sabo dam and adding a belly section, it is common to embed a large number of wire rods (reinforcing bars) 21 (at approximately 1m pitch lengthwise and widthwise) into the existing dam 11 to ensure the concrete strength, attach formwork 22 to maintain the shape to the wire rods 21 to form gaps, and pour concrete 23 into these gaps to construct the belly section 20, as shown in Figures 6(A) and 6(B).

[0004] Meanwhile, a technique has been disclosed in which precast blocks are placed on an existing dam and fixed to the existing dam with filling concrete (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7228281 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the concrete of the belly portion 20 shrinks, leakage water (colored portion) W from the existing dam 11 may enter the inside of the belly portion 20 or the boundary between the existing dam 11 and the belly portion 20, which may cause the concrete to deteriorate. In addition, when using ready mixed concrete to shore up an existing sabo dam, there are cases where the dam is located far from the ready mixed concrete plant or where access to the site is not easy. Furthermore, in the future, it is expected that there will be further obstacles to concrete procurement due to a shortage of workers and changes in labor policies, such as reductions in working hours and overtime hours.

[0007] Therefore, there is a demand for technology relating to an erosion-control dam structure and an erosion-control dam construction method that can be carried out in a construction that can suppress deterioration of the apex of a reconstructed erosion-control dam during reconstruction work that adds a apex to an existing dam.

[0008] The present invention has been devised based on this technical background, and aims to provide a sabo dam structure and a sabo dam construction method that can be applied to existing sabo dams and enables construction that suppresses deterioration of the belly portion of a reconstructed sabo dam. [Means for solving the problem]

[0009] Therefore, the inventors conducted intensive research into technology for constructing erosion control dams that can suppress deterioration of the belly portion when renovating existing erosion control dams, and discovered that it is effective to install anchors in the existing dam body, and then pour fluid-type erosion control soil cement created by mixing locally generated soil or a base material made by mixing locally generated soil with modifiers such as crushed stone or steelmaking slag and cement milk into the space formed by connecting the anchors with external protective material placed on the outside of the existing dam body, and then to create a structure with an integrated structure consisting of the dam body of the existing dam and the fluid-type erosion control soil cement. Also, unlike concrete, sabo soil cement has a high water-cement ratio and contains irregular fine particles in the soil generated on-site, making it impossible to control the quality of the base material. Moreover, the gravel contained in the soil generated on-site has a variety of properties, from stable to weathered, so sabo soil cement flowable type is more susceptible to shrinkage and cracking than ready-mix concrete. Furthermore, if the existing dam body has deteriorated and formed a water channel, water may seep into the gaps created by shrinkage and cracks, leading to destruction. Therefore, it was decided to address the defects caused by the characteristics of sabo soil cement flowable type used as a material for reconstructing sabo dams, such as shrinkage and susceptibility to cracking.

[0010] The present invention relates to The existing dam and A support member having one end connected to the existing dam; an external protective material connected to the other end side of the support member and disposed to form a space between the external protective material and the existing dam; A structure disposed between the existing dam and the external protective material; Equipped with The outer protective material is provided with drainage holes, The structure is formed of an erosion control soil cement flow type in which an erosion control soil cement material is generated by mixing a base material of locally generated soil or locally generated soil mixed with at least one of modifiers, crushed stone and steel slag, with cement milk, and is cast between the existing dam and the external protective material and solidified. It is characterized by death, or A drain pipe is disposed within the structure and connected to the drain hole. It is characterized by: or The water drain pipe has an opening formed on a peripheral surface. It is characterized by: or A method for constructing a sabo dam structure comprising: an existing dam; a support member having one end connected to the existing dam; an external protective material connected to the other end of the support member and disposed opposite an outer wall surface of the existing dam; and a structure disposed between the existing dam and the external protective material, One end of the support member is connected to the outer wall surface of the existing dam, On the other end side of the support member External protection with drainage holes The existing dam and the external A space is formed between the protective members, In the space between the existing dam and the external protective material, an erosion control soil cement material is poured and solidified to form a structure made of an erosion control soil cement flow type, by mixing a base material of locally generated soil or locally generated soil mixed with at least one of modifiers of crushed stone and steel slag and cement milk with the base material. Characterized by death, or Together with the external protective material, A drain pipe connected to the drain hole is installed in correspondence with the drain hole. It is characterized by: or Together with the external protective material, a drain pipe having an opening on the periphery and connected to the drain hole is provided corresponding to the drain hole; It is characterized by the above. Effect of the Invention

[0011] According to the erosion-control dam structure and erosion-control dam construction method of the present invention, it has been pointed out that erosion-control soil cement may shrink or crack depending on the quality of the base material. However, because a structure made of flowable-type erosion-control soil cement is fastened together with external protective materials and support members, it has an integrity and the tensile strength of the structure is safe against internal water pressure, etc., making it possible to construct safe facilities regardless of the instability of the quality of the internal materials of a structure made of flowable-type erosion-control soil cement. Furthermore, by forming a drainage structure in the sabo dam structure, even if shrinkage or cracks occur due to the quality of the base material, the sabo soil cement can drain harmful water and prevent deterioration. In addition, by using a structure made of flowable erosion control soil cement, not only can the soil near the construction site be effectively utilized, but it can also make it possible to build facilities that are not dependent on the circulation of ready-mix concrete. [Brief description of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram illustrating the general configuration of a sabo dam structure according to one embodiment of the present invention, viewed along the dam length direction. FIG. [Diagram 2] FIG. 2 is a schematic configuration diagram shown in the direction of arrow II in FIG. 1 , illustrating an example of an external protective material applied to a sabo dam structure according to one embodiment. [Diagram 3] FIG. 2 is a schematic diagram illustrating an example of a drainage pipe applied to a sabo dam structure according to one embodiment. [Figure 4] FIG. 13 is a schematic diagram illustrating a modified example of a drainage pipe applied to a sabo dam structure according to one embodiment. [Diagram 5] FIG. 1 is a conceptual diagram illustrating a method for constructing a sabo dam according to one embodiment, viewed along the dam length direction. [Figure 6] FIG. 1 is a conceptual diagram illustrating problems with conventional dam reconstruction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a sabo dam structure according to one embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig. 1 is a conceptual diagram showing the schematic configuration of an erosion-control dam structure according to one embodiment of the present invention, viewed along the dam length, and Fig. 2 is a schematic configuration diagram showing an example of an external protective material applied to the erosion-control dam structure, as viewed in the direction of arrow II in Fig. 1. Fig. 3 is a schematic configuration diagram showing an example of a drainage pipe applied to the erosion-control dam structure according to one embodiment, and Fig. 4 is a schematic configuration diagram showing a modified example of the drainage pipe. In the figures, reference numeral 1 denotes the erosion-control dam structure, reference numeral 11 denotes the existing dam, reference numeral 12 denotes the support member, reference numeral 13 denotes the external protective material, reference numerals 14 and 14A denote drainage pipes, and reference numeral 15 denotes the erosion-control soil-cement structure.

[0014] 1, the sabo dam structure 1 includes, for example, an existing dam 11, a support member 12, an external protective material 13, a drainage pipe 14, and soil cement 15. In this embodiment, an outer wall surface 11A of the existing dam 11 is located on the downstream side in the event of a debris flow.

[0015] The existing dam 11 is constructed of, for example, concrete, and has a substantially trapezoidal dam body that is wider at the bottom and narrows toward the top when viewed in the dam length direction. The existing dams 11 are installed, for example, in mountainous areas where landslides are a concern, and many of them have deteriorated over time or do not meet the standards. In addition, for existing dams 11 installed in places where it is difficult to dispose of the large amounts of soil that accumulate in sabo dams and river basins after soil erosion caused by landslides, this is rational because it allows the use of such soil as material. The installation location and the number of years since installation of the existing dam 11 may be set arbitrarily. Also, it is particularly effective to apply this to an existing dam in a place where it is difficult to transport ready-mixed concrete (for example, a remote area where the road width of the transportation route is long or the transportation time is long).

[0016] The support member 12 can be set arbitrarily, but is, for example, made of a deformed round bar with one end serving as an integral anchor. The anchor portion of the support member 12 on one end is embedded and fixed from the outer wall surface 11A of the existing dam 11 into the dam body made of concrete or erosion control soil cement. It is desirable to determine the depth and thickness of the anchor portion of the support member 12 so as to be safe against water pressure and freezing.

[0017] Specifically, adhesive is injected into anchor holes drilled in advance in the existing dam 11, and one end is inserted into the anchor hole, thereby directly fixing the support member 12 via the adhesive to the concrete or erosion control soil cement that constitutes the existing dam 11. Note that the fixing of the support member 12 to the existing dam 11 can be set arbitrarily, and the support member 12 may be pressed into the existing dam 11, or a bracket connected to the outer wall surface 11A may be fixed to the existing dam 11 using an anchor member. The support members 12 are arranged, for example, at the intersections of a grid set at intervals of 1 m in the horizontal and vertical directions on the outer wall surface 11A of the existing dam 11.

[0018] The arrangement of the support members 12 and the spacing between the support members 12 can be set arbitrarily, and the spacing in the horizontal and vertical directions may be set to different dimensions, or the spacing between some of the support members 12 in either or both the horizontal and vertical directions may be made larger or smaller to set an arrangement with non-uniform spacing (locally dense or sparse). In addition, the length, embedded dimensions, and size (for example, diameter, etc.) of the support members 12 can also be set arbitrarily.

[0019] The external protective material 13 is formed, for example, from a rectangular steel plate, and as shown in Figure 2, a plurality of drainage holes 13H are formed at regular intervals in both the horizontal direction (X direction) and the vertical direction (Y direction) of the sabo dam structure 1, penetrating the external protective material 13 in the thickness direction. Further, the external protective material 13 is connected to the tip (other end side) of the support member 12 via a welded joint, and is disposed opposite the outer wall surface 11A of the existing dam 11 with a gap therebetween. Furthermore, the external protective material 13 not only secures the shape of the structure 15 as a formwork, but also has the functions of protecting against deterioration and securing the cross section, and by being in close contact with the structure 15 and acting as a part of the structure 15, it also has the function of integrating the existing dam 11 and the structure 15. (

[0020] The connection between the external protective material 13 and the support member 12 is not limited to a welded joint, and can be set arbitrarily. For example, the connection may be made to a bracket fixed to the support member 12 using a fastening member (e.g., a bolt, etc.). Furthermore, the configuration of the external protective material 13 (shape, thickness, horizontal and vertical dimensions, etc.) can be set arbitrarily, and is not limited to steel plate but may be made of concrete, expanded metal, artificial stone, landscaping materials, or a combination of these.

[0021] The arrangement, number and size of the drainage holes 13H may be set arbitrarily. In addition, since the structure 15 made of flowable type sand-control soil cement is restrained by the external protective material 13 and the embankment body of the existing dam 11, there is a possibility that cracks will appear in the hardened structure 15 made of flowable type sand-control soil cement due to shrinkage, etc., and it is preferable to set the cracks in a certain form (equally spaced, etc.) to prevent water from entering through the cracks and causing destruction due to freezing or expansion.

[0022] The drainage holes 13H may be additionally formed based on cracks in the existing dam 11, etc. The existing embankment 11 may have cracks due to deterioration over time, and these can be checked daily by observing the surface during construction. If water has seeped into the cracks, the intrusion can be confirmed by a change in color. If water intrusion is confirmed, the crack is likely to become a water channel, so drainage holes 13H and drainage pipes 14 can be installed depending on the observation results and the severity of the problem.

[0023] The drain pipe 14 is formed in a cylindrical shape that communicates with one end side 14R and the other end side 14F, and is made of a resin material such as polyvinyl chloride. As shown in FIG. 3, an opening 14H is formed in the peripheral surface in the longitudinal and circumferential directions, penetrating the peripheral surface in the thickness direction and connecting the inner peripheral surface and the outer peripheral surface. Specifically, the openings 14H are formed at 90° intervals in the circumferential direction at the same position in the longitudinal direction, and adjacent positions in the longitudinal direction are shifted by 45° in the circumferential direction. Further, the drain pipe 14 is connected to the external protective material 13 at a position corresponding to the drain hole 13H, for example by adhesive. Since the drain pipe 14 has openings 14H formed around the entire circumference, water passing below the drain pipe 14 can also be taken into the drain pipe 14.

[0024] Also, like a water drain pipe 14A shown as a modified example in FIG. 4, openings 14H may be formed in the circumferential and longitudinal directions about halfway in the circumferential direction of the cylinder. According to the water drainage pipe 14A, an opening 14H is formed on half of the circumference, and by positioning the part where the opening 14H is formed on the upper side, water in the water drainage pipe 14A is prevented from leaking into the structure 15, and the water can be efficiently passed through the water drainage pipe 14A and discharged from the drainage hole 13H of the external protective material 13.

[0025] The material (resin, metal such as iron), cross-sectional shape when viewed in the longitudinal direction (rectangular or polygonal such as square pipe), size, length, arrangement of openings 14H (pitch and circumferential angle), range, number, size, etc. of the drainage pipe 14 may be set arbitrarily. Also, a drainage pipe without openings 14H may be used. In addition, it is preferable to position the drainage hole 13H and the water drainage pipe 14 so that if there are cracks in the embankment of the existing dam 11 that could become water channels, the infiltrating water is guided to the drainage hole 13H.

[0026] The structure 15 is formed of a soil cement flow type in which an erosion control soil cement material is generated by mixing a base material, for example, locally generated soil and sand, with a modifier made of crushed stone and steel slag, with cement milk, and then poured into the space formed between the outer wall surface 11A of the existing dam 11 and the external protective member 13, and allowed to solidify. The use of steel slag as a modifier is advantageous in that the weight of the structure 15 increases. In addition, the structure 15 may be formed using a soil cement fluid type in which an erosion control soil cement material made by mixing crushed stone and cement milk with on-site soil and sand is poured and solidified, or a modifier consisting of at least one of crushed stone and steelmaking slag may be applied, or other modifiers may be mixed in addition to the modifier consisting of either one or both of crushed stone and steelmaking slag, or other modifiers may be mixed in instead of crushed stone or steelmaking slag.

[0027] Hereinafter, a method for constructing a sabo dam according to one embodiment will be described with reference to FIG. FIG. 5 is a conceptual diagram illustrating an example of a method for constructing a sabo dam according to one embodiment, taken along the dam length direction.

[0028] (1) Connection of the existing dam 11 and the support member 12 The existing dam 11 and the support member 12 are connected by burying an anchor portion (one end side) of the support member 12 from an outer wall surface 11A of the existing dam 11 as shown in FIG. 5(A). The support members 12 are positioned so as to correspond to the intersections of the grid at preset intervals in the lateral (horizontal) and vertical (height) directions. Note that when positioning the support members 12, the position of the support members 12 may be determined by observing discoloration that occurs as water passes through the outer wall surface 11A of the existing dam, or additional support members 12 may be positioned at positions determined by discoloration in addition to the above intersections.

[0029] (2) Exterior wall surface 11A and external Formation of spaces between protective members 13 As shown in FIG. 5(B), an external protective material 13 is connected to the tip (other end) of the support member 12 to form an outer wall surface 11A of the existing dam 11. externalA space is formed between the protective members 13 . The outer protection 13 is connected to the support member 12, for example by welding. It is efficient to use an external protective material 13 connected to the support member 12 that has drainage holes 13H formed in advance at a factory, etc. Note that additional drainage holes 13H may be formed on-site based on discoloration of the exterior wall surface 11A, etc. In addition, if leakage is found from a location other than the controlled location (drainage hole 13H) after construction is completed, an additional drainage hole 133H may be drilled as a measure to deal with unexpected events (in this case, since the sabo soil cement material has hardened, the drainage pipe 14 may not be installed).

[0030] (3) Installation of drain pipe 14 The drain pipe is installed on the support member 12 as shown in FIG. external After the protective member 13 is welded (connected), the water drain pipe 14 is bonded (connected) to correspond to the drain hole 13H. The drain pipe 14 is aligned with the drain hole 13H. external The protective member 13 is bonded (connected) to the rear surface (surface on the outer wall surface 11A side) of the protective member 13 and then attached to the supporting member 12. external The protective member 13 may be welded (connected), or the drain pipe 14 may be temporarily placed on the outer wall surface 11A of the existing dam 11 prior to the connection of the external protective member 13, and then the drain pipe 14 may be connected to the support member 12. external The protective member 13 may be welded (connected).

[0031] (4) Formation of a structure made of sabo soil-cement flow type When forming a structure made of erosion control soil cement flow type in the space between the existing dam 11 and the external protection material 13, for example, locally generated soil and sand mixed with modifiers made of crushed stone and steel slag is mixed with cement milk to produce erosion control soil cement material. Based on the erosion control soil cement handbook, the erosion control soil cement material is made of, for example, a design standard strength of 3N / mm 2 It is preferable to set the temperature to the above level, taking into consideration the effects of freezing and deterioration. Then, as shown in FIG. 5(D), the generated sabo soil cement material is poured into the space between the existing dam 11 and the external protective material 13 and allowed to harden to form a structure made of fluid-type sabo soil cement.

[0032] According to one embodiment of the erosion-control dam structure 1 and erosion-control dam construction method, a structure 15 made of fluid-type erosion-control soil cement is fastened by an external protective material 13 and a support member 12, and as a result the structure 15 has an integrated structure and its tensile strength is safe against internal water pressure, etc., and a safe erosion-control dam structure 1 can be constructed regardless of the instability of the quality of the internal material of the structure 15. In addition, the use of flowable erosion control soil cement not only promotes the effective use of soil and sand near the reconstruction site, but also prevents it from being dependent on the circulation of ready-mix concrete. Furthermore, since the structure 15 of the sabo dam structure 1 is formed of a fluid type sabo soil cement, it is possible to form a structure 15 having excellent density similar to that of concrete.

[0033] In addition, since the erosion-control dam structure 1 is equipped with a plurality of drainage holes 13H and water-drainage pipes 14 arranged at regular intervals, the structure 15 made of flowing type erosion-control soil cement is restrained by the external protective material 13 and the embankment body of the existing dam 11, and cracks occurring in the hardened structure 15 made of flowing type erosion-control soil cement due to shrinkage, etc. can be prevented from causing water to enter through the cracks and freeze or expand, thereby destroying the structure 15.

[0034] The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, the sand-control dam structure 1 is described as having an external protective material 13 having a drainage hole 13H formed therein, and a drainage pipe 14, but the structure may not have a drainage pipe 14, or may have an external protective material 13 in which a drainage hole 13H is not formed.

[0035] In the above embodiment, the drainage holes 13H are formed in the external protective material 13 in advance. However, the drainage holes 13H may be formed after the external protective material 13 is connected to the support member 12. In the above embodiment, the case has been described in which the bank body of the existing dam 11 is made of concrete, but it is not limited to concrete and may be made of soil cement (sabo soil cement) or the like. In the above embodiment, the sabo dam structure 1 is described as being attached to the outer wall surface 11A on the downstream side of the existing dam 11, but the present invention may be applied to a reconstructed dam in which the dam is attached to the upstream side of the existing dam 11, or to both the downstream and upstream sides of the existing dam 11. The present invention may also be applied to a reconstructed dam having a raised portion in addition to the above dam structure.

[0036] The construction method of the sabo dam described in the above embodiment is merely an example, and may be set arbitrarily without being limited thereto. For example, the installation order and connection method of each component may be set appropriately.

[0037] In the above embodiment, the drainage holes 13H are formed in the external protective material 13 in advance. However, the drainage holes may be formed after the external protective material 13 is connected to the support member 12. In addition, in the above embodiment, a case has been described in which the drainage pipe 14 is connected to the tip of the support member 12 and then adhered (connected) to correspond to the drainage hole 13H of the external protective material 13. However, for example, the external protective material 13 to which the drainage pipe 14 has already been connected may be connected to the tip of the support member 12, or the drainage pipe 14 may be temporarily placed on the outer wall surface 11A before installing the external protective material 13, and then the external protective material 13 may be connected to the support member 12. [Explanation of symbols]

[0038] 1. Sabo dam structure 11 Existing dam 12 Support member 13 External protection material 13H Drain hole 14 Drain pipe 14H opening 15 Soil-cement erosion control structure

Claims

1. The existing dam and A support member having one end connected to the existing dam; an external protective material connected to the other end side of the support member and disposed to form a space between the external protective material and the existing dam; A structure disposed between the existing dam and the external protective material; Equipped with The structure is formed of an erosion control soil cement flow type in which an erosion control soil cement material is generated by mixing a base material of locally generated soil or locally generated soil mixed with at least one of modifiers, crushed stone and steel slag, with cement milk, and is cast between the existing dam and the external protective material and solidified. A sabo dam structure characterized by the above.

2. A drainage hole is formed in the external protective material.

2. The sabo dam structure according to claim 1 .

3. A drain pipe is disposed within the structure and connected to the drain hole.

3. The sabo dam structure according to claim 2.

4. The water drain pipe has an opening formed on a peripheral surface.

4. The sabo dam structure according to claim 3.

5. A method for constructing a sabo dam structure comprising: an existing dam; a support member having one end connected to the existing dam; an external protective material connected to the other end of the support member and disposed opposite an outer wall surface of the existing dam; and a structure disposed between the existing dam and the external protective material, One end of the support member is connected to the outer wall surface of the existing dam, The external protective material is connected to the other end side of the support member to form a space between the existing dam and the protective member, In the space between the existing dam and the external protective material, an erosion control soil cement material is poured and solidified to form a structure made of an erosion control soil cement flow type, by mixing a base material of locally generated soil or locally generated soil mixed with at least one of modifiers of crushed stone and steel slag and cement milk with the base material. A method for constructing a sabo dam comprising the steps of:

6. An external protective material having a drainage hole is connected to the other end of the support member.

6. A method for constructing a sabo dam according to claim 5,

7. Together with the external protective material, A drain pipe connected to the drain hole is installed in correspondence with the drain hole.

7. A method for constructing a sabo dam according to claim 6,

8. Together with the external protective material, a drain pipe having an opening formed on the periphery thereof and connected to the drain hole is installed in correspondence with the drain hole; 7. A method for constructing a sabo dam according to claim 6,

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