Water-stopping structure in joints

Abstract

To prevent an in-joint cut-off structure which can prevent water from leaking below a water supply structure from a joint even when a joint material installed in the joint of the water supply structure is partially damaged to leak.SOLUTION: An in-joint cut-off structure 4 for preventing water from leaking below a water supply structure from a joint 7 of a water supply structure (apron 1) includes a first layer of a grout material (for example, shrinkage-compensating mortar) 8 which is installed at a lower part in the joint 7, and a second layer of a water expansion cut-off material 10 installed in the joint 7 so as to overlap the first layer. The water expansion cut-off material 10 is composed of water expansion rubber 11 arranged in the width-direction center of the joint 7, and one pack type water expansion elastic seal materials 12 which are arranged in width-direction both sides of the water expansion rubber 11, and fill a gap between the water expansion rubber 11 and a side wall of the joint 7.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] This invention relates to an in-joint water-stopping structure that is installed in concrete joints forming hydraulic structures (e.g., dam aprons, riverbeds, etc.) and prevents water from leaking downward through the joints. [Background technology]

[0002] Conventionally, concrete aprons of dams as hydraulic structures have joints at appropriate intervals, and the joints absorb deformation (expansion or contraction) of the concrete caused by environmental changes (e.g., temperature changes) around the dam, preventing damage (e.g., cracking) of the concrete caused by excessive deformation. If a power station is installed below the apron, joint material (e.g., elastic filler) is placed in the joints to prevent water from leaking from the joints into the power station (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-245912 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the joint material in the apron joints may be damaged or washed away due to the force of the water flowing over the apron when water is discharged. In such cases, there is a risk that water will leak from the damaged or washed away joint material into the power plant located under the apron, causing the generator to stop.

[0005] Therefore, an object of the present invention is to provide an in-joint water-stopping structure that can prevent water from leaking from the joint to below the hydraulic structure (for example, to the power plant side below the apron) even if the joint material is partially damaged or leaks out. [Means for solving the problem]

[0006] The present invention relates to an in-joint water stop structure 4 that prevents water leakage from a joint 7 of a hydraulic structure (e.g., an apron 1 of a dam 3) to below the hydraulic structure. The in-joint water stop structure 4 of the present invention comprises a first layer of grout material (non-shrink mortar) 8 installed in the lower part of the joint 7, and a second layer of a water-expanding water stop material 10 installed in the joint 7 and overlapping the first layer. Effect of the Invention

[0007] In the water-stopping structure in joints according to the present invention, even if the second layer of water-expansion water-stopping material is damaged or washed away, the first layer of grout material seals the joints, preventing water from leaking out of the joints below the hydraulic structure. [Brief description of the drawings]

[0008] [Figure 1] This is a cross-sectional view of a part of a dam with a power station under the apron. [Diagram 2] Figure 2(a) is a plan view of the apron (a view taken along arrow A in Figure 1 rotated 90 degrees clockwise), Figure 2(b) is a cross-sectional view of a first embodiment of an intra-joint water-stopping structure taken along line BB in Figure 2(a), Figure 2(c) is a cross-sectional view of a second embodiment of an intra-joint water-stopping structure taken along line BB in Figure 2(a), and Figure 2(d) is a cross-sectional view of a third embodiment of an intra-joint water-stopping structure taken along line BB in Figure 2(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that, although the following embodiments will be described taking a dam apron as an example of a hydraulic structure, the present invention can be widely applied to other hydraulic structures (e.g., riverbeds, etc.).

[0010] (First embodiment) FIG. 1 is a partial cross-sectional view of a dam 3 equipped with a powerhouse 2 under (on the back side of) an apron 1. FIG. 2(a) is a plan view of the apron 1 (a view taken along the arrow A in FIG. 1 rotated 90° clockwise). FIG. 2(b) is an enlarged cross-sectional view of a first embodiment of an intra-joint water-stopping structure 4 taken along line B1-B1 in FIG. 2(a). The cross-sectional view taken along line B2-B2 in FIG. 2(a) is the same as the cross-sectional view shown in FIG. 2(b).

[0011] As shown in Figures 1 and 2(a)-(b), when water is discharged from the outlet 5 of the dam 3, it flows down with force along a slope 6, and the water that flows down the slope 6 flows downstream (to the right side in Figure 1, or the lower side in Figure 2(a)) along the surface (upper surface) 1a of the apron 1.

[0012] The apron 1 of the dam 3 is mainly made of concrete because it needs to be strong enough to support the water flow when the water is discharged. However, if the apron 1 of the dam 3 is made of concrete, it will deform due to environmental changes (e.g., temperature changes) around the dam 3, and will be susceptible to damage such as cracks. For this reason, the apron 1 of the dam 3 is generally configured with joints (gaps) 7 at appropriate intervals (at appropriate intervals along the width direction shown in FIG. 2(a) and at appropriate intervals along the flow direction shown in FIG. 2(a)) to absorb deformation of the concrete with the joints 7, so that the concrete will not be damaged by environmental changes (e.g., temperature changes) around the dam 3. The concrete apron 1 is supported on the underside 1b side by a steel frame material such as an I-beam (not shown).

[0013] In this embodiment, the power station 2 is installed directly below the apron 1. In other words, the ceiling of the power station 2 is formed by the apron 1. Therefore, if water leaks from the apron 1, water will fall from the apron 1 into the power station 2, and the water may splash on equipment such as a generator installed in the power station 2, causing the generator to break down. Therefore, as shown in FIG. 2(b), the apron 1 according to this embodiment employs an in-joint water-stopping structure 4 that closes the joint (gap) 7, thereby preventing water from leaking from the joint 7 into the power station 2.

[0014] The water-sealing structure 4 in the joint shown in FIG. 2(b) has a two-layer structure, in which the first layer installed in the lower part of the joint 7 (deep on the power station 2 side) is made of grout material (e.g., non-shrink mortar) 8, and the second layer installed in the joint 7 and on top of the first layer of grout material 8 is made of water-expanding water-sealing material 10 (water-expanding rubber 11 (e.g., elastic filler) and one-component water-expanding elastic sealant 12 (e.g., Polysealer UK by ThreeBond Unicom Co., Ltd.)). The water-expanding water-sealing material 10 constituting the water-sealing structure 4 in the joint is arranged in a position where its upper surface 10a is recessed from the surface 1a of the apron 1, and is designed not to come into direct contact with water flowing over the surface 1a of the apron 1 (not to be directly impacted by the flowing water). Furthermore, the water-expanding water-stopping material 10 has a water-expanding rubber 11 disposed in the widthwise center of the joint 7, and a one-component water-expanding elastic sealant 12 disposed on both widthwise sides of the water-expanding rubber 11, so that the one-component water-expanding elastic sealant 12 fills the gap between the water-expanding rubber 11 and the side walls of the joint 7. The intra-joint water-stopping structure 4 shown in Fig. 2(b) can be used in place of a conventional intra-joint water-stopping structure not only when a new apron 1 is installed, but also when the apron 1 is repaired, to reliably prevent water leakage from the joint 7.

[0015] In this embodiment, as shown in Fig. 2(b), a gutter 13 is installed along the joint 7 on the underside 1b of the apron 1 (ceiling surface of the power station 2). As a result, even if the water-stopping function of the in-joint water-stopping structure 4 becomes insufficient for some reason, the gutter 13 can receive water leaking from the joint 7 and guide it to a drain outlet not shown in the figure, thereby preventing the water leaking from the joint 7 from falling onto equipment in the power station 2. In other words, in this embodiment, the in-joint water-stopping structure 4 installed in the joint 7 of the apron 1 and the gutter 13 installed along the joint 7 on the ceiling surface of the power station 2 constitute a double water-leakage prevention structure against water leaking from the joint 7 of the apron 1, and a fail-safe technical concept is applied.

[0016] (Effects of the first embodiment) In the joint water-stopping structure 4 of this embodiment, the upper surface 10a of the second layer of water-expanding water-stopping material 10 is positioned at a position recessed from the surface 1a of the apron 1 and does not directly contact the water flowing over the surface 1a of the apron 1. As a result, the second layer of water-expanding water-stopping material 10 is less likely to be damaged or flow out for a long period of time, and water leakage from the joint 7 to the power plant 2 can be prevented for a long period of time.

[0017] In the joint water-stopping structure 4 of this embodiment, even if the second layer of water-expanding water-stopping material 10 is damaged or washed away for some reason, the first layer of grout material 8 seals the joint 7, preventing water from leaking from the joint 7 into the power plant 2.

[0018] (Second Example) Fig. 2(c) is a diagram showing an intra-joint water stop structure 4 according to a second embodiment of the present invention, which is a modified example of the intra-joint water stop structure 4 shown in Fig. 2(b). In this embodiment, the same parts as those in the intra-joint water stop structure 4 of the first embodiment are denoted by the same reference numerals, and explanations that overlap with those in the first embodiment will be omitted.

[0019] As shown in Figure 2(c), the joint water-stopping structure 4 of this embodiment is formed so that the upper surface 10a of the second layer of water-expanding water-stopping material 10 is located on the same plane as the surface 1a of the apron 1 (without protruding upward from the surface 1a of the apron 1).

[0020] In the joint water-stopping structure 4 of this embodiment, the upper surface 10a of the second layer of water-expanding water-stopping material 10 does not protrude from the surface 1a of the apron 1, and the second layer of water-expanding water-stopping material 10 does not collide with water flowing on the surface 1a of the apron 1. As a result, the second layer of water-expanding water-stopping material 10 is less likely to be damaged or flow out for a long period of time, and water leakage from the joint 7 to the power plant 2 side can be prevented for a long period of time.

[0021] Furthermore, in the joint water-stopping structure 4 of this embodiment, like the joint water-stopping structure 4 of the first embodiment, even if the second layer of water-expanding water-stopping material 10 is damaged or washed away for some reason, the first layer of grout material 8 seals the joint 7, preventing water from leaking from the joint 7 into the power plant 2.

[0022] (Third Example) Fig. 2(d) is a diagram showing an intra-joint water stop structure 4 according to a third embodiment of the present invention, which is a modified example of the intra-joint water stop structure 4 shown in Fig. 2(b). In this embodiment, the same parts as those in the intra-joint water stop structure 4 of the first embodiment are denoted by the same reference numerals, and explanations that overlap with those in the first embodiment will be omitted.

[0023] As shown in FIG. 2(d), the joint water-stopping structure 4 of this embodiment is composed of a first layer of grout material (e.g., non-shrink mortar) 8, a second layer of water-expanding water-stopping material 10, and a third layer of grout material 14 (e.g., polymer cement mortar, underwater adhesive, high-fluidity epoxy grout (Alphatech 841, product name by Alpha Industries, etc.). The third layer of grout material 14 is placed on top of the second layer of water-expanding water-stopping material 10, and is formed so that its upper surface 14a is located on the same plane as the surface 1a of the apron 1 (without protruding upward from the surface 1a of the apron 1).

[0024] In the intra-joint water stop structure 4 according to this embodiment, the upper surface 14a of the third layer of grout material 14 does not protrude from the surface 1a of the apron 1, and the third layer of grout material 14 does not collide with water flowing on the surface 1a of the apron 1, so the third layer of grout material 14 is unlikely to be damaged or washed away for a long period of time, and the third layer of grout material 14 can prevent the second layer of water-expanding water stop material 10 from being damaged or washed away for a long period of time. As a result, the intra-joint water stop structure 4 according to this embodiment is more effective at preventing water leakage from the joint 7 to the power plant 2 side than the first and second embodiments.

[0025] Furthermore, even if the third layer of grout material 14 of the joint water stopping structure 4 of this embodiment is damaged or leaks out for some reason, the overall structure will be the same as that of the joint water stopping structure 4 of the first embodiment, and the second layer of water-expanding water stopping material 10 and the first layer of grout material 8 will continue to seal the joint 7, so that water can be prevented from leaking from the joint 7 into the power plant 2 in the same way as the joint water stopping structure 4 of the first embodiment.

[0026] Furthermore, in the joint water-stopping structure 4 of this embodiment, even if the third layer of grout material 14 and the second layer of water-expanding water-stopping material 10 are damaged or washed away for some reason, the first layer of grout material 8 seals the joint 7, preventing water from leaking from the joint 7 into the power plant 2.

[0027] (Other Examples) The present invention is not limited to the hydraulic structures (apron 1 of dam 3) in each of the above-mentioned embodiments, but can be widely applied to cases where, for example, the riverbed of a river (the structure facing apron 1) as a hydraulic structure is made of concrete, joints are formed in the riverbed, and a railway tunnel or road (the structure corresponding to power plant 2) is installed below the riverbed. [Explanation of symbols]

[0028] 1...Apron (hydraulic structure), 4...Water-stopping structure in joint, 7...Joint, 8...Grout material, 10...Water-expanding water-stopping material

Claims

1. In a water-stopping structure in a joint that prevents water from leaking from the joint of a hydraulic structure to below the hydraulic structure, a first layer of grout material disposed in a lower portion of the joint; A second layer of water-expanding water-stopping material is installed in the joint and on top of the first layer; Equipped with The water-expanding waterproofing material is composed of a water-expanding rubber disposed in the widthwise center of the joint, and a one-component water-expanding elastic sealant disposed on both sides of the water-expanding rubber in the widthwise direction, filling the gap between the water-expanding rubber and the side walls of the joint. A water-stopping structure within a joint.

2. a third layer of grout material disposed within the joint and overlying the second layer; 2. The water-stopping structure according to claim 1,

3. The second layer is installed at a position recessed from the upper surface of the water structure.

2. The water-stopping structure according to claim 1,

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