Earth retention wall and method for constructing an earth retention wall

Abstract

This invention provides a retaining wall and a method for constructing a retaining wall that can efficiently stop water leakage from the ground on the back side to the excavation side. [Solution] The present invention provides a retaining wall 10 comprising a plurality of main piles 11 driven into the ground at predetermined intervals, a plurality of horizontal sheet piles 12 stacked and spread between the main piles 11, and a water-swellable waterproofing agent 13 provided between the plurality of horizontal sheet piles 12. The water-swellable waterproofing agent 13 preferably contains at least one selected from a urethane-based swelling resin and a superabsorbent polymer.

Description

Technical Field

[0004] , , , , , , , ,

[0001] The present disclosure relates to a retaining wall and a method for constructing a retaining wall.

Background Art

[0002] When constructing a structure underground, after excavating the ground to form a cavity, a retaining wall is constructed to prevent the side surface of the surrounding ground from collapsing. Generally, a sheet pile wall with anchor piles or a soil-cement column wall is used as the retaining wall. Depending on the groundwater level of the underground ground, groundwater may seep out from the retaining wall. In particular, the sheet pile wall with anchor piles has a large amount of water leakage and is not applicable in a ground where the groundwater level is shallower than the excavated ground (also referred to as the floor surface), and it is common to use other construction methods. In a similar construction method to the sheet pile wall with anchor piles, as a countermeasure, for example, Patent Document 1 discloses a sheet pile wall with anchor piles structure including a plurality of H-shaped steels, a concrete wall cast between the H-shaped steels, and a copper sheet pile fixed to the H-shaped steels, and a configuration in which a water-expandable waterstop material is interposed between the flange of the H-shaped steel and the copper sheet pile. Examples of the water-expandable waterstop material include a water-expandable rubber member. In addition, Patent Document 2 discloses a sheet pile wall with anchor piles type waterproof and protective fence used for flood countermeasures in a river, including anchor piles and a sheet pile sandwiched between the anchor piles. This sheet pile is made of a resin plate-like body, and waterstop materials made of foamed EPDM are attached to the upper end and the lower end for the purpose of improving and ensuring the watertightness between the sheet piles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] ]]((END]]However, if the groundwater level rises further above the excavation level, water may leak into the excavation area. Also, if water leaks into the sheet pile wall due to an unexpected rise in the groundwater level, water will accumulate in the excavation area, making it difficult to continue underground construction and requiring considerable effort for drainage. Furthermore, if soil from the back of the site flows into the excavation area due to the water leakage, harmful settlement and subsidence may occur in the ground on the back side. This invention has been made in view of the above circumstances, and aims to provide a retaining wall and a method for constructing a retaining wall that can efficiently stop water leakage from the back side ground to the excavation side. [Means for solving the problem]

[0005] The present invention provides the following means. [1] The present invention relates to a retaining wall comprising a plurality of main piles driven into the ground at predetermined intervals, a plurality of horizontal sheet piles stacked while bridging between the main piles, and a water-swellable water-stopping agent provided between the plurality of horizontal sheet piles. [2] The retaining wall described in [1] above comprises at least one of a water-swellable waterproofing agent selected from a urethane-based swelling resin and a superabsorbent polymer. [3] A retaining wall as described in [1] or [2] above, wherein multiple horizontal sheetings are made of wood. [4] A method for constructing a retaining wall comprising a main pile driving step of driving multiple main piles into the ground at predetermined intervals, and a horizontal sheet pile installation step of stacking multiple horizontal sheet piles between the main piles, wherein in the horizontal sheet pile installation step, a water-swellable waterproofing agent is applied to the stacked surface of one horizontal sheet pile, and then other horizontal sheet piles are stacked on the stacked surface on which the water-swellable waterproofing agent has been applied. [5] A method for constructing a retaining wall as described in [4], wherein the water-swellable waterproofing agent contains a urethane-based swelling resin, and the water-swellable waterproofing agent is applied to the laminated surface. [6] A water-swellable water-stopping agent contains a superabsorbent polymer, and in the sheet pile installation process, an adhesive tape equipped with a superabsorbent polymer-supported layer carrying the superabsorbent polymer is attached to the laminated surface of one sheet pile as described in [4]. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a retaining wall and a method for constructing a retaining wall that can efficiently stop water leakage from the back side ground to the excavation side. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic front view showing one embodiment of a retaining wall. [Figure 2] This is a schematic plan view showing one embodiment of the earth retention wall of the present invention. [Figure 3] This is a cross-sectional view of AA in Figure 2. [Figure 4] This is a schematic front view showing another embodiment of the retaining wall. [Figure 5] This is a schematic side view showing one embodiment of a retaining wall. [Figure 6] This is a schematic front view showing the construction flow of the retaining wall. [Figure 7] This is a schematic perspective view showing horizontal sheet piles. [Figure 8] This is a schematic plan view showing another embodiment of the retaining wall. [Figure 9] This is a schematic perspective view showing the reinforcing plate. [Modes for carrying out the invention]

[0008] One embodiment of the present invention will be described in detail below with reference to the drawings.

[0009] [Earth retaining wall] The earth retention wall of the present invention prevents the collapse of the ground when excavating the construction area, and efficiently prevents groundwater from leaking out from the ground behind the earth retention wall to the excavation side due to a rise in the groundwater level. Figure 1 shows a schematic front view of the retaining wall of this embodiment. As shown in Figure 1, the retaining wall 10 comprises a plurality of main piles 11 driven into the ground at predetermined intervals, a plurality of horizontal sheet piles 12 stacked and bridged between the main piles 11, and a water-swellable water-stopping agent 13 provided between the plurality of horizontal sheet piles 12. Details of each component will be described below.

[0010] (Parent pile) In this embodiment, an H-shaped steel is used as the parent pile 11 for explanation. The H-shaped steel 11 includes a web 11a, and flanges 11b and 11c. The H-shaped steel 11 is driven into the ground G (see FIG. 5) at a predetermined interval and is rooted to a position deeper than the excavated ground 15a (see FIG. 5).

[0011] (Cross bracing sheet pile) FIG. 2 shows a plan view of the retaining wall 10. The cross bracing sheet piles 12 are bridged and laminated between the H-shaped steels 11. Specifically, as shown in FIG. 2, one cross bracing sheet pile 12 is bridged by abutting both ends of the cross bracing sheet pile 12 against the back ground G1 side of the flanges 11b of two adjacent H-shaped steels 11. Then, as shown in FIG. 1, a plurality of cross bracing sheet piles 12 are laminated while being bridged to form a wall structure. The area partitioned by the retaining wall 10 is the excavation area 15. The cross bracing sheet pile 12 used for the retaining wall 10 of the present invention is preferably made of wood so that it can be constructed and removed simply at low cost. A publicly known cross bracing sheet pile 12 made of wood can be used, and its size is appropriately adjusted according to the interval between the parent piles 11.

[0012] (Water-swellable waterstop) As shown in FIG. 1, a water-swellable waterstop 13 is provided between the upper and lower cross bracing sheet piles 12 that are laminated. The water-swellable waterstop 13 can be provided between the cross bracing sheet piles 12 by the method described later. The water-swellable waterstop 13 preferably contains at least one selected from urethane-based swellable resins and superabsorbent polymers (Super Absorbent Polymer). Examples of the water-swellable waterstop containing a urethane-based swellable resin include those containing a urethane prepolymer that swells by moisture. Among commercially available products, “Pile Lock (registered trademark) NS-v” (solvent-free type) manufactured by Nippon Chemical Paint Co., Ltd. can be mentioned.

[0013] The amount and thickness of the water-swellable waterproofing agent 13 applied should preferably be adjusted as appropriate depending on the area of ​​the laminated surface 12a of the sheet piles 12, the characteristics of the excavated ground, etc.

[0014] Examples of superabsorbent polymers include polyacrylic acid, sodium polyacrylate, polyvinyl alcohol, and polyethylene glycol. Among these, polyacrylic acid and sodium polyacrylate are preferred. Considering the ease of application to the sheet piles 12, the superabsorbent polymer is preferably used as an adhesive tape, for example, comprising an adhesive layer and a superabsorbent polymer-supported layer on which the superabsorbent polymer is carried. Examples of commercially available water-swelling waterproofing agents containing superabsorbent polymers include "Pilelock®" (quick-drying type) manufactured by Nippon Chemical Paint Co., Ltd., and "Chemica Sheet®" manufactured by Nippon Chemical Paint Co., Ltd. in tape form.

[0015] Figure 3 shows the cross-sectional view AA in Figure 2. Because a water-swellable waterproofing agent 13 is provided between the horizontal sheet piles 12, as shown in Figure 3, even if the groundwater level WL rises to a position higher than the excavated ground 15a, the water-swellable waterproofing agent 13 can absorb the groundwater that overflows to the backfill ground G1 side and swell, thereby sealing the gaps between the horizontal sheet piles 12. Therefore, although in the past groundwater sometimes leaked from the backfill ground G1 to the excavation area 15 through the gaps between the horizontal sheet piles 12, according to the present invention, it is possible to efficiently prevent the accumulation of groundwater in the excavation area 15. Furthermore, the effort required for drainage treatment, which was previously necessary when water leakage occurred, can be eliminated. Moreover, the adverse effects and risks to the surrounding area of ​​the construction site due to water leakage can also be reduced.

[0016] (Other configurations) In this embodiment, as shown in Figure 4, the retaining wall 10 may be provided with reinforcing plates 14 that span multiple sheet piles 12 in order to fix the sheet piles 12. The reinforcing plates 14 can be easily installed by arranging them so that their longitudinal direction is vertical and fixing them to the sheet piles 12 with nails or the like. Wooden boards called half-length boards can be used as the reinforcing plates 14.

[0017] [Methods for constructing retaining walls] The method for constructing a retaining wall according to this embodiment comprises a main pile driving step of driving multiple main piles into the ground at predetermined intervals, and a horizontal sheet pile installation step of stacking multiple horizontal sheet piles between the main piles, wherein in the horizontal sheet pile installation step, a water-swellable waterproofing agent is applied to the stacked surface of one horizontal sheet pile, and then other horizontal sheet piles are stacked on the stacked surface on which the water-swellable waterproofing agent has been applied. The following explains the details of each step.

[0018] (Main pile driving process) The main pile driving process involves driving multiple main piles into the ground at predetermined intervals. In this embodiment, H-shaped steel is used as the main pile. Figure 5 shows the ground G after the vertical hole 21 has been drilled, as a side view including the backfill ground G1 and the excavation area 15. Figure 6 shows the construction flow of the retaining wall as a front view. First, as shown in Figure 5, a vertical hole 21 is drilled for driving in the H-shaped steel beam 11. The vertical hole 21 is drilled vertically into the ground G of the excavation area 15 using a drilling machine such as an auger. Next, as shown in Figure 6(a), main piles 11, which are H-shaped steel beams, are driven into each of the excavated vertical holes 21 (not shown). At this time, the portion of the piles embedded below the set excavated ground 15a is filled with a foundation reinforcement material. In addition, the portion of the vertical hole 21 above the excavated ground 15a in which the main piles 11 have been driven is backfilled with soil and sand. The driving of H-shaped steel beams 11 into the ground G is generally done using a wheeled crane such as a rough terrain crane or truck crane, along with a vibro-hammer.

[0019] Next, the excavation area 15 (see Figure 5), which is separated by lines connecting the driven H-shaped steel beams 11, is excavated with the excavator 22. First, for example, excavation is carried out to a depth of 2m. Then, from the excavated area, i.e., the excavation area 15 side, the space between the main piles 11 is excavated. At this time, bracing, struts, etc., may be appropriately provided to support the retaining wall 10 being constructed from the excavation side.

[0020] (Horizontal sheet pile installation process) Next, as shown in Figure 6(b), multiple horizontal sheet piles 12 are stacked and installed between the H-shaped steel beams 11. Specifically, the ends of the horizontal sheet piles 12 are brought into contact with the flanges 11b of the adjacent H-shaped steel beams 11 (see Figure 2), thereby bridging the horizontal sheet piles 12 between the main piles 11. In this invention, during the sheet pile installation process, a water-swellable waterproofing agent 13 is applied to the laminated surface 12a (see Figure 7) of one sheet pile 12, and then another sheet pile 12 is laminated on the laminated surface 12a on which the water-swellable waterproofing agent 13 is applied. In this way, the sheet piles 12 are laminated while providing the water-swellable waterproofing agent 13 between the sheet piles 12. As described above, the water-swellable water-stopping agent 13 can be one that contains at least one of a urethane-based swelling resin and a superabsorbent polymer. If the water-swellable waterproofing agent 13 contains a urethane-based swelling resin, in the sheet pile installation process, after installing one sheet pile 12, the water-swellable waterproofing agent 13 containing the urethane-based swelling resin is applied to the laminated surface 12a of the sheet pile 12. Known methods such as brushes, rollers, and sprays can be used for application. If the water-swellable waterproofing agent 13 contains a superabsorbent polymer, in the sheet pile installation process, an adhesive tape equipped with a superabsorbent polymer-supported layer carrying the superabsorbent polymer is attached to the laminated surface 12a of one sheet pile 12.

[0021] Furthermore, as shown in Figure 6(c), the excavation of the excavation area 15 is advanced to the excavation area 15a. Then, the process of stacking the sheet piles 12 is repeated while applying the water-swellable waterproofing agent 13 to the stacking surface 12a of the sheet piles 12. The water-swellable waterproofing agent 13 may be applied to the laminated surface 12a after the horizontal sheet piles 12 have been erected between the H-shaped steel beams 11, or the horizontal sheet piles 12 with the water-swellable waterproofing agent 13 applied to the laminated surface 12a in advance may be erected between the H-shaped steel beams 11.

[0022] As described above, the retaining wall 10 of this embodiment may be provided with reinforcing plates 14 for fixing the sheet piles 12. As shown in Figure 8, the reinforcing plates 14 are installed vertically adjacent to the flange 11b of the H-shaped steel 11 and the sheet piles 12. As shown in Figure 9, it is preferable to provide a water-swellable waterproofing agent 13 on the back surface 14a that contacts the sheet piles 12 and the side surface 14b that contacts the flange 11b. As described above, if the water-swellable waterproofing agent 13 contains a urethane-based swellable resin, the water-swellable waterproofing agent containing the urethane-based swellable resin is applied to the back surface 14a and the side surface 14b, and then the plate is driven onto the sheet pile 12. Alternatively, if the water-swellable waterproofing agent 13 contains a superabsorbent polymer, a reinforcing plate 14 is prepared in advance by attaching an adhesive tape equipped with a superabsorbent polymer-supported layer to the back surface 14a that contacts the sheet pile 12 and the side surface 14b that contacts the flange 11b, and the plate is driven onto the sheet pile 12 so that the side with the adhesive tape is in contact with the flange 11b and the sheet pile 12.

[0023] The retaining wall 10 equipped with the reinforcing plate 14 absorbs and swells groundwater leaking from the gap between the flange 11b and the sheet pile 12, thereby preventing water leakage more efficiently than when the water-swellable waterproofing agent 13 is provided only between the sheet piles 12. [Explanation of Symbols]

[0024] 10 Retaining wall 11 Main pile, H-shaped steel 12 Horizontal sheet piles 12a Laminated surface 13. Water-swelling water-stopping agent 14 Reinforcement plate 15 Excavation Area 15a Excavated ground 21 Vertical hole 22 Excavators G Ground G1 back ground WL Groundwater level

Claims

1. Multiple main piles driven into the ground at predetermined intervals, Multiple horizontal sheet piles are stacked while bridging each other between the aforementioned main piles, A water-swellable water-stopping agent is provided between the aforementioned plurality of horizontal sheet piles, A retaining wall equipped with a shoring system.

2. The retaining wall according to claim 1, wherein the water-swellable water-stopping agent comprises at least one selected from a urethane-based swelling resin and a superabsorbent polymer.

3. The retaining wall according to claim 1 or 2, wherein the plurality of horizontal sheeting piles are made of wood.

4. The process involves driving multiple main piles into the ground at predetermined intervals, A process of installing horizontal sheet piles, which involves stacking multiple horizontal sheet piles while erecting them between the aforementioned main piles, A method for constructing a retaining wall comprising: A method for constructing a retaining wall, comprising the process of installing horizontal sheet piles, wherein a water-swellable waterproofing agent is applied to the laminated surface of one horizontal sheet pile, and then other horizontal sheet piles are laminated on the laminated surface on which the water-swellable waterproofing agent is applied.

5. The water-swellable water-stopping agent contains a urethane-based swelling resin, A method for constructing a retaining wall according to claim 4, wherein the water-swellable waterproofing agent is applied to the laminated surface.

6. The water-swellable water-stopping agent contains a superabsorbent polymer, The method for constructing a retaining wall according to claim 4, wherein in the step of installing the sheet piles, an adhesive tape having a water-absorbent polymer-supported layer on which the water-absorbent polymer is supported is attached to the laminated surface of one of the sheet piles.

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