JP2012140813A - Sheet pile with drainage function, and sheet pile bulkhead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet pile with a drainage function and a sheet pile bulkhead, easy to manufacture and handle, excellent in workability, and hard to clog with sediment.SOLUTION: Inside a steel sheet pile 2 in a U-shape, a hat-shape or the like, e.g., a drainage member 4 is mounted which is formed in a solid netted structure. The solid netted structure formed by welding the contact points of linear bodies of polypropylene or the like to one another has a tight portion 4a near the surface and a rough portion 4b inside thereof and may also have a hollow portion 4c inside thereof. It is wholly shaped long cylindrical with an approximately rectangular cross section or the like. The drainage member 4 whose lower and upper ends are mounted on a web 2a of the steel sheet pile 2 in a U-shape, a hat-shape or the like via a front end mounting member 5 and a rear end mounting member 6, respectively. The lower and upper ends are integrated with the steel sheet pile 2 to be placed in a ground as it is. The tight portion 4a near the surface functions to prevent the entry of sediment during earthquake, and the rough portion 4b and the hollow portion 4c inside thereof disperse excess pore water pressure to inhibit the liquefaction of the ground.

Description

  TECHNICAL FIELD The present invention relates to a seismic reinforcing wall body, earth retaining wall, sheet pile with drainage function and sheet pile wall used in ground where liquefaction may occur during an earthquake.

  In landfills and other grounds where liquefaction may occur during an earthquake, drainage members (drain materials) with a drainage function are placed in the ground or drained into sheet piles or piles as a countermeasure against liquefaction. Various techniques have been developed to suppress liquefaction by attaching and laying members and dissipating excess pore water pressure through these drainage members during an earthquake.

  For example, Patent Document 1 discloses a drain pipe for preventing liquefaction, in which a mesh filter for preventing infiltration of soil particles is covered on the outer periphery of a pipe having a large number of holes for water permeability.

  In addition, in Patent Document 2 by the applicant of the present application, a three-dimensional network structure is attached to the outer periphery of a steel pipe, a resin pipe, a steel bar or other rod-like body, and a filter for preventing intrusion of earth and sand is further attached to the outer periphery. A drainage member for countermeasures against liquefaction is disclosed.

  Similarly, Patent Document 3 by the applicant of the present application discloses that a ribbed flat plate having a large number of openings is attached to a predetermined section of a sheet pile to form a drainage space for liquefaction countermeasures. A filter to prevent intrusion of earth and sand is also attached to the flat plate opening.

  In addition, Patent Document 4 discloses a structure in which a drain member is integrated with a sheet pile so that the drain member and the sheet pile can be driven simultaneously.

  Moreover, in patent document 5 by the applicant of this application, grooved steel is attached to the web part of a hat-shaped steel sheet pile, and many drain holes with a filter are provided in the web part or grooved steel of a hat-shaped steel sheet pile, Or what attached the perforated board which provided many drainage holes with a filter between the flange parts, and formed the drainage space for liquefaction countermeasures is disclosed.

  In addition, as the above-described three-dimensional network structure, for example, there is one in which a contact of a resin linear body such as polypropylene is welded, and as described in Non-Patent Document 1, it is commercially available as a drainage member for civil engineering. .

Japanese Patent Publication No. 06-011990 Japanese Patent No. 2663603 Japanese Patent No. 3031336 JP-A-10-168868 JP 09-242100 A

"Hetimaron and civil engineering use", [online], Shinko Nylon Co., Ltd. [searched on November 26, 2010], Internet <URL: http://www.shinko-nylon.co.jp/doboku/index.html >

  In the conventional drainage member for countermeasures against liquefaction as described above, it is common to use a synthetic resin having a fine mesh or a thin filter made of synthetic fiber in order to prevent clogging due to intrusion of earth and sand.

  However, these filters have a problem that they are easily damaged when being placed on the ground such as a drainage member or a sheet pile integrated with the drainage member, or when transported.

  In some cases, a filter protection member may be attached to the outer periphery of the filter. However, the production labor, construction labor, and material costs for attaching the protection member will increase, and if the protection member is left in the ground, the water permeability will be increased accordingly. There is also the problem of being damaged.

  Further, in the type in which an opening is provided in a steel material or a resin pipe constituting the drainage and the filter is attached to the opening, damage to the filter can be suppressed to some extent, but there is a problem that production costs and material costs increase.

  The present invention is intended to solve such problems, and as a sheet pile in which drainage members are integrated, it is easy to manufacture and handle, has excellent workability, and does not easily cause clogging due to earth and sand. It is intended to provide a sheet pile wall.

  In the invention according to claim 1 of the present application, a drainage member made of a resin three-dimensional network structure extending in the longitudinal direction of the sheet pile main body is integrated with a sheet pile main body that is placed in the soil or in water to form a wall body. In the sheet pile with drainage function, the network structure near the surface of the drainage member is made denser than the inner network structure.

  When the sheet pile body is a steel sheet pile, the steel sheet pile includes a U-shaped steel sheet pile, a hat-shaped steel sheet pile, a Z-shaped steel sheet pile, a straight steel sheet pile, an H-shaped steel sheet, and a hat-shaped steel sheet pile ( Or the steel materials which combined the left-right asymmetric steel sheet pile), the combination steel sheet pile of steel sheet piles, a steel pipe sheet pile, an H-shaped steel sheet pile, etc. can be mention | raise | lifted. The sheet pile body may be concrete. In any case, the sheet pile with a drainage function of the present invention can be easily manufactured by attaching a drainage member.

  In addition, these sheet piles can be easily connected by fitting the joints on both sides when placing in the soil or in the water. Can be placed at the same time.

  A drainage member made of a resinous three-dimensional network structure is typically formed by welding contacts of a resin linear body such as polypropylene, polyethylene terephthalate, or polyester, and by changing the thickness or density of the linear body, The size of the internal space can be adjusted.

  In the present invention, for the resin three-dimensional network structure as the drainage member, the network structure near the surface is made denser than the inner network structure, so that the drainage performance upward is exerted mainly on the inner side where the network structure becomes rough. In addition, since the surface side where the network structure is dense exhibits a filter function to prevent intrusion of earth and sand, a filter made of synthetic fibers or the like, which has conventionally been a problem of damage, can be omitted.

  In addition, the resin-made three-dimensional network structure is hard to be damaged because it is more resistant to wear than a general filter, and even if it is partially damaged, the gap is formed in a three-dimensional shape, so there is almost no effect on performance. In addition, it has pressure resistance and can maintain a shape shaped by itself.

  Therefore, it is possible to directly install in the ground without providing a protection member for the drainage member. However, the combined use of a filter and a protective member is not hindered.

  The density of the network structure in the vicinity of the surface and the inner network structure is not limited to the two steps of dense and coarse, but may be changed in multiple steps, or may be changed continuously.

  In addition, since liquefaction is likely to occur in a relatively loose sandy ground where the pore water at a depth of about 20 m or less from the ground surface is saturated, drainage members for liquefaction measures are also liquid depending on the local ground. What is necessary is just to attach to a required range with respect to the layer determined to be a formation layer.

  In the event of an earthquake, as with conventional liquefaction countermeasures, excess pore water pressure is dissipated through the drainage member, and liquefaction of the ground is suppressed.

  According to a second aspect of the present invention, in the sheet pile with drainage function according to the first aspect, the interior of the drainage member is hollow.

  If the interior of the drainage member is made hollow, there is almost no resistance to drainage in the hollow part, so that drainage performance can be improved. However, it may be advantageous to have no hollow portion in terms of shaping and pressure resistance.

  According to a third aspect of the present invention, in the sheet pile with drainage function according to the first or second aspect, at least a part of the drainage member is joined to the sheet pile main body.

  In the present invention, the integration of the drainage member and the three-dimensional resin network structure may be performed as long as the drainage member is mounted on the sheet pile main body and can be placed in the soil or in water at the same time. Attached to the main body, or simply fixed with a jig or steel wire, etc., only the lower part of the drainage member joined to the sheet pile body, and the lower part of the drainage member and the intermediate position of the drainage member etc. Etc. Moreover, even if the drainage member is slightly separated from the sheet pile main body, it is sufficient that some part of the drainage member is fastened to the sheet pile main body.

  According to a fourth aspect of the present invention, in the sheet pile with a drainage function according to the first, second, or third aspect, an area ratio of a gap in the network structure in the vicinity of the surface of the drainage member is 4% or more.

  If the area ratio of the gaps in the network structure in the vicinity of the surface of the drainage member is about 4% or more, it is considered that the drainage performance is not greatly impaired.

  According to a fifth aspect of the present invention, in the sheet pile with a drainage function according to any one of the first to fourth aspects, one or a plurality of the drainage members are attached to one side or both sides of the sheet pile main body.

  Depending on the width and cross-sectional shape of the sheet pile, multiple drainage members may be attached in the width direction of one sheet pile main body. Also, if liquefaction measures are required on both sides of the wall body, or the mounting area to the wall body When increasing, it can also attach to both surfaces of a sheet pile main body.

  Claim 6 is a sheet pile with a drainage function according to claims 1 to 5, and when the outer surface of the drainage member and / or the interior of the drainage member is hollow, the inner surface of the hollow side is covered with a filter. It is characterized by this.

  In the present invention, since the surface side of the resinous three-dimensional network structure that is dense has a filter function to prevent intrusion of earth and sand, a filter made of synthetic fibers or the like that has been a problem of damage is omitted. However, under conditions where the filter is less damaged, it is possible to prevent the entry of finer soil particles and prevent clogging of the three-dimensional network structure by using a filter made of synthetic fibers, etc. It can be further ensured.

  In this case, the filter is preferably made of synthetic fiber or synthetic resin. For example, a warp knitted fabric made of nylon or polyethylene monofilament, or a nonwoven fabric made of polypropylene or polyester fiber can be used. . Alternatively, a filter may be formed by combining synthetic fibers, synthetic resins, or combining or overlapping synthetic resins and synthetic resins.

  The mesh interval or gap between warp woven fabric and non-woven fabric as a filter may cause clogging of the filter due to soil taking into account the particle size distribution of the soil (generally sand ground) to be liquefied. Set to not.

As a method of attaching the filter to the surface of the three-dimensional network structure, the filter can be wound around the outer periphery of the three-dimensional network structure and the end of the filter is fastened with a fastener. Further, the outer periphery of the wound filter may be fastened with a wire, a rope or the like, or may be fastened with a fastening band or the like.
As another method for attaching the filter, when the hollow portion is provided in the three-dimensional network structure, the filter may be installed near the outer surface of the hollow portion.

  A seventh aspect of the present invention is the sheet pile with a drainage function according to the first to sixth aspects, wherein the drainage member is protected by a protective member.

  When the protective member is covered with a resin-made three-dimensional network structure or a filter made of synthetic fibers or the like, the protective member is integrated with the purpose of preventing damage to the filter, or a resin-made three-dimensional network structure. Used for smooth sheet pile placement.

  For example, even when placing on a hard ground mixed with pointed stones or the like, the sheet pile with a drainage member can be more safely placed on the ground by using the protective member together. In other words, when protecting a drainage member covered with a conventional filter with a protective member having a large number of small holes, it was difficult to drive without damaging the filter. Can be placed even on harsh ground with almost no degradation of the filter function.

  In addition, if an auxiliary method such as a water jet or prior stirring of the ground is used, the sheet pile with a drainage member of the present invention can be placed more safely.

  The protective member may be made of metal such as steel or stainless steel, or synthetic resin such as polyethylene or reinforced plastic.

  When leaving the protective member in the soil as it is after placing the sheet pile with the drainage member, it is necessary to use a material having water permeability by providing a large number of small holes. When pulling out later, a protective member without a hole can also be used.

  Moreover, the structure which protects the outer peripheral part of a drainage member entirely using a cylindrical body may be sufficient as a protection member.

  An eighth aspect of the present invention is the sheet pile with a drainage function according to the seventh aspect, wherein the protective member is a protective member having an opening ratio of 4% or more.

  Claim 8 is defined from the viewpoint of drainage performance as a countermeasure against liquefaction, as in Claim 4, and if the opening ratio of the protective member is about 4% or more, it is considered that drainage performance is not greatly impaired. .

  From the viewpoint of drainage performance, more preferably, if the opening ratio of the protective member is 8% or more, the drainage function of the drainage material is not significantly impaired, and the function of liquefaction countermeasures can be effectively exhibited.

  However, when the opening ratio of the protective member is 20% or more, it is preferable in terms of drainage performance, but the cost increases and the opening ratio increases in order to ensure the strength and rigidity as the protective member. This is disadvantageous in terms of protecting drainage members or filters.

  According to a ninth aspect of the present invention, in the sheet pile with a drainage function according to the seventh or eighth aspect, the protection member is detachable from the sheet pile main body or the drainage member.

  By making the protection member detachable with respect to the sheet pile main body or the drainage member, the protection member can be pulled out and diverted after placing the sheet pile with the drainage member.

  In addition, when leaving the protective member in the soil as it is after placing it, it is necessary to use a material having water permeability by providing a large number of small holes, etc., but when pulling out after placing the sheet pile with the drainage member Since a protective member without a hole can be used, damage to the resin-made three-dimensional network structure and the filter at the time of placing can be more reliably prevented.

  The sheet pile wall with a drainage function according to claim 10 is a sheet pile wall formed by connecting a number of sheet piles with a drainage function according to claims 1 to 9, and is attached to one side with respect to the projected area of the sheet pile wall. Further, the projected area of the drainage portion of the drainage member is 8% or more.

  It is self-evident that the drainage section provided on the sheet pile increases the drainage / collection function as the width in the sheet pile wall direction increases, but it is often selected in terms of workability and rigidity. U-shaped steel sheet piles and hats When a steel sheet pile is considered, the position and width at which the drainage member can be provided is limited from the shape of the sheet pile.

  In addition, when considering the installation cost, ease of construction, drainage efficiency, etc., analytically related to the width of the sheet pile wall and the width of the drainage section in the direction of the sheet pile wall (the sum of the widths of multiple drainage sections) The projected area of the drainage part of the drainage member relative to the projected area of the sheet pile wall is desirably 8% or more in general ground.

  Furthermore, although it depends on the nature of the ground, if the projected area of the drainage part of the drainage member relative to the projected area of the sheet pile wall is 10% or more, it is greatly reduced compared to the case where the projected area of the drainage part is 100%. It is considered that the drainage function can be performed.

  In the present invention, the network structure in the vicinity of the surface of the resin three-dimensional network structure as a drainage member integrated with the sheet pile is made denser than the inner network structure, so that the vicinity of the surface where the network structure becomes dense is intruded by earth and sand. It is possible to omit a filter made of a synthetic fiber or the like that has exhibited a filter function for preventing the damage and has been a problem of damage in the past.

  In addition, the resin-made three-dimensional network structure is less likely to be damaged than a general filter, and even if it is partially damaged, the gap is formed in a three-dimensional shape, so there is almost no influence on the performance and the pressure resistance is improved. It is possible to keep the shape shaped by itself.

  Therefore, it is also possible to directly drive and install in the ground without providing a drainage member protection member. Depending on the use environment and conditions, a filter or a protective member may be applied.

  Since the drainage member is attached to the sheet pile main body constituting the wall body, the effect of suppressing liquefaction at the wall body position is ensured, and since the drainage member is integrated with the sheet pile, transportation and grounding are performed. Efficient in installation work.

1 shows an embodiment of a sheet pile with a drainage function of the present invention, (a) is a sectional view perpendicular to the member axial direction, (b) is a front view, (c) is an enlarged sectional view of only a drainage member, d) is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a perspective view corresponding to FIG. 1. It is a perspective view at the time of applying to a U-shaped steel sheet pile as other embodiment of the sheet pile with a drainage function of this invention. (a)-(d) is sectional drawing which shows the variation of the drainage member used by this invention. (a)-(d) is a horizontal sectional view which shows the example of the sheet pile wall using the sheet pile with a drainage function of this invention, respectively. The case where a protection member is provided is shown as other embodiments of a sheet pile with a drainage function of the present invention, (a) is a sectional view perpendicular to the member axial direction, and (b) is a perspective view. 6A and 6B show a case where the protective member is a flat punching metal as a modification of the embodiment of FIG. 6, in which FIG. 6A is a cross-sectional view perpendicular to the member axial direction, and FIG. It is the perspective view which showed the case where a protection member is a welded wire mesh as another modification of embodiment of FIG. An embodiment in which the protective member is detachable from the sheet pile, (a) is a perspective view of the entire sheet pile with a drainage function, (b) is a sectional view of the detachable part, (c) is the detachable part. It is sectional drawing of another example. It is the perspective view which showed the attachment / detachment mechanism and extraction procedure in the case of drawing out only a protection member after placement using a protection member without an opening part as other embodiment. It is explanatory drawing regarding the attachment area ratio with respect to the sheet pile wall of a drainage member, (a) is a top view, (b) is a front view.

  Hereinafter, specific embodiments of the present invention will be described. Note that the present invention is not limited to the embodiments described below.

  FIG. 1 shows an embodiment of a sheet pile with a drainage function of the present invention, where (a) is a cross-sectional view perpendicular to the member axial direction, (b) is a front view, and (c) is an enlarged view of only a drainage member. Sectional drawing, (d) is an AA sectional view of (a), and FIG. 2 is a perspective view corresponding to FIG.

  In this embodiment, as shown in FIG. 1 (a), the sheet pile body is surrounded by a hat-shaped steel sheet pile 2 that can be connected in the same direction by a left-right asymmetric joint, a web 2a of J pile (trade name), and a flange 2b. A drainage member 4 made of a three-dimensional network structure is attached to the inside.

  In the present embodiment, the three-dimensional network structure constituting the drainage member 4 is formed by welding the contacts of a linear body such as polypropylene, and as shown in FIG. A rough portion 4b is formed on the inner side, and a hollow portion 4c is further formed on the inner side, and the whole is shaped into a long cylindrical body having a substantially rectangular cross section.

  The drainage member 4 shaped in this way is placed along the longitudinal direction of the hat-shaped steel sheet pile 2, as shown in FIGS. 1 (b), (d) and FIG. In this example, the drainage member 4 is integrated with the hat-shaped steel sheet pile 2 by attaching the lower end and upper end of the drainage member 4 to the web 2a of the hat-shaped steel sheet pile 2 with the front end mounting member 5 and the rear end mounting member 6, respectively. It can be set up.

  By providing the drainage member protection plate 7 on the top of the tip mounting member 5 as shown in FIG. 1, the drainage member is damaged due to the effect of temporarily relaxing the ground density in the vicinity of the drainage member when placing the ground of the sheet pile. Concerns can be reduced.

  The drainage member 4 may be attached by fixing the tip and restraining the intermediate portion of the drainage member 4 to the sheet pile body.

  The dense portion 4a in the vicinity of the surface has a function of preventing intrusion of earth and sand. Preferably, the gap in the network structure of the dense portion 4a (referring to the interval excluding the fiber thickness of the network) is within an average of 10 mm. Depending on the ground conditions, for example, it may be about 0.5 mm or about 1 mm. Moreover, even if it is the same clearance gap, if the thickness of the dense part 4a is made thick, the penetration | invasion suppression effect of a soil particle is large. Practically, it is sufficient in many cases if the invasion of soil particles having a size of about 0.2 mm to 0.5 mm or more can be considerably prevented, and the gap and thickness of the dense portion 4a in the vicinity of the surface are set as such. do it. Some intrusion of sand or silt with a particle size of less than that is often not a problem from the viewpoint of maintaining the drainage function, but the invasion of finer particles is suppressed depending on the ground conditions and usage conditions. The gap and thickness of the dense portion 4a may be selected.

  The rough portion 4b and the hollow portion 4c inside the drainage member 4 have a drainage function. That is, the underground interstitial water that has flowed into the drainage member 4 is drained from the upper end portion of the drainage member 4 through the rough portion 4b and / or the hollow portion with low water resistance.

  In addition, about the front-end | tip attachment member 5, as shown in FIG.1 (d), the resistance in placing in the ground is reduced by tapering a lower end so that it can be driven smoothly.

  FIG. 3: is a perspective view at the time of applying to the U-shaped steel sheet pile 3 as a sheet pile main body as another form of a sheet pile with a drainage function. The drainage member 4 is aligned with the longitudinal direction of the U-shaped steel sheet pile 3, and the lower end and the upper end thereof are attached to the web 3a of the U-shaped steel sheet pile 3 by the front end attachment member 5 and the rear end attachment member 6, respectively. 3 is the same as that of the hat-shaped steel sheet pile 2 in FIG. 2 so that it can be placed in the ground as it is.

  4A to 4D are sectional views perpendicular to the axial direction showing variations of the drainage member 4 used in the present invention.

  In the example of FIG. 4A, as in FIG. 1, a dense portion 4a is formed in the vicinity of the surface, a rough portion 4b is formed inside, and a hollow portion 4c is further formed inside thereof. Shaped into a long cylindrical body.

  In this example, the core material 4d is inserted in order to form the hollow portion 4c, but the core material 4d may be omitted. As the core material 4d, a hollow tube having a hole or a wire net rolled into a cylindrical shape can be used.

  The example of FIG. 4B is a case where there is no hollow portion 4c as compared with the example of FIG. The example of FIG.4 (c) is a case where the drainage member 4 is shape | molded into the elongate cylindrical body of a cylindrical cross section as a whole with respect to the example of Fig.4 (a). Further, the example of FIG. 4D is a case where there is no hollow portion 4c as compared with the example of FIG.

  In addition, various variations are conceivable, such as the shape, the arrangement of dense and rough portions, and the case of using a faithful core material.

  5A to 5D are horizontal sectional views showing examples of sheet pile walls using the sheet pile with a drainage function of the present invention.

  5 (a), like FIG. 1, the drainage member 4 is attached to the inner side surrounded by the web 2a and the flange 2b of the hat-shaped steel sheet pile 2, and connected in the same direction by a left-right asymmetric joint. 1 is constructed.

  At the time of an earthquake, excess pore water pressure is dissipated through the drainage member 4, and liquefaction of the ground is suppressed.

  FIG. 5B shows the sheet pile wall 1 by attaching the drainage member 4 to the inner side surrounded by the web 3a and the flange 3b of the U-shaped steel sheet pile 3 and connecting the orientations alternately by joints at both ends. It is a thing.

  In the above example, the drainage member 4 includes one web (in the case of FIG. 5 (a)) surrounded by the web 2 a of the hat-shaped steel sheet pile 2 and the flange 2 b, or the web 3 a of the U-shaped steel sheet pile 3. Although one strip (in the case of FIG. 5B) is attached to the inner side surrounded by the flange 3b, it can also be attached to the opposite side of the webs 2a and 3a. A plurality of drainage members 4 may be attached to one sheet pile main body.

  FIGS. 5C and 5D correspond to FIGS. 5A and 5B in which the drainage members 4 are attached to the surfaces on both sides of the webs 2a and 3a, respectively.

  FIG. 6 shows a case where a protective member is provided as another embodiment of the sheet pile with a drainage function of the present invention, wherein (a) is a cross-sectional view perpendicular to the member axial direction, and (b) is a perspective view. is there.

  In this example, a protective member 21 having a large number of small holes 22 provided in the web portion of the grooved steel 21a is used as the protective member, and the protective member 21 is attached along the longitudinal direction of the U-shaped steel sheet pile 3. 4 is attached to cover the surface.

  The protective member 21 made of the channel steel 21a can be attached to the web 3a of the U-shaped steel sheet pile 3 by spot welding or the like, for example.

  The small holes 22 are not limited to circular holes as shown in the figure, and may be rectangular or slit-shaped. In this case, in order not to impair the drainage function of the drainage member 4, the aperture ratio of the many small holes 22 on the front surface of the protection member 21 is set to 4% or more, more preferably 10% or more.

  The configuration other than the protection member 21 is basically the same as the embodiment of FIG. The tip mounting member 5 for fastening the drainage member 4 and the lower end of the protection member 21 may be simply joined by spot welding or the like.

  Although not shown in FIG. 6 because the protective member 21 is used, if the surface of the drainage member 4 is covered with a synthetic fiber filter to prevent the entry of fine soil particles, a three-dimensional network structure Further prevention of clogging of the body drainage member 4 can be further ensured.

  Moreover, in this example, although the type of FIG.4 (b) is shown as the drainage member 4, the type which has the hollow part 4c of Fig.4 (a) may be used.

  FIG. 7 shows a case where the protective member 21 is a flat punching metal 21b as a modification of the embodiment of FIG. 6, wherein (a) is a sectional view perpendicular to the member axial direction, and (b) is a perspective view. FIG.

  The protective member 21 may be any member that has strength and rigidity that can prevent damage to the drainage member 4 and the like during placement, and FIG. 7 uses a punching metal 21b instead of the perforated channel steel 21a shown in FIG. It is. In this case, the side surface of the drainage member 4 is exposed.

  The concept of the aperture ratio of the punching metal 21b as the protective member 21 is the same as in the case of FIG. 6, and may be 4% or more, more preferably 10% or more.

  FIG. 8 is a perspective view showing a case where the protective member is a welded wire mesh 21c as still another modification of the embodiment of FIG.

  The basic concept of the embodiment of FIG. 8 is the same as that of the embodiment of FIGS. 6 and 7, but the protective member 21 is cheaper and easy to install. In this case, the strength and rigidity of the welded wire mesh 21c do not matter so much, but it is necessary to pay attention so that the surface of the drainage member 4 and the like is not damaged by increasing the aperture ratio.

  In this example, the front end mounting member 5 and the rear end mounting member 6 for mounting the drainage member 4 also serve as a fixture for the welded wire mesh 21 c as the protection member 21.

  FIG. 9 shows an embodiment in which the protective member is detachable from the sheet pile, (a) is a perspective view of the entire sheet pile with a drainage function, (b) is a sectional view of the detachable portion, (c) FIG. 9 is a cross-sectional view of another example of the detachable portion.

  In this embodiment, as shown to Fig.9 (a), the drainage member 4 which consists of a solid network structure is attached to the inner side surrounded by the web 3a and the flange 3b of the U-shaped steel sheet pile 3, The U-shaped steel sheet pile 3 is provided with a perforated plate 21d having a large number of small holes 22 (water-permeable holes) as a removable protective member 21.

  As shown in FIG. 9B, the hole-piercing plate 21d as the protection member 21 is inserted inside the locking member 23 provided on the flange 3b of the U-shaped steel sheet pile 3, and the drainage member 4 and the locking member 23 are inserted. The U-shaped steel sheet pile 3 and the drainage member 4 are placed as they are. The locking member 23 may be continuous in the longitudinal direction of the U-shaped steel sheet pile 3, but rather it is easier to install a short one discontinuously at a predetermined interval.

  At the time of placement, the drainage member 4 is protected by the perforated plate 21d as the protection member 21 so that the drainage member 4 is not damaged. After the placement, only the protection member 21 is pulled upward so that the protection member 21 is drained. No obstruction to water flow to 4.

  In this way, on the premise that the protective member 21 is removed after the placement, the protective member 21 may not have the small hole 22, and a steel plate or other panel without a hole having a necessary strength may be used.

  FIG. 9 (c) is such that a perforated plate 21d as the protective member 21 is placed between the doubly provided locking members 23. Compared to that of FIG. 9 (b), the protective member 21 is It can be delivered stably.

  FIG. 10 is a perspective view showing an attaching / detaching mechanism and a pulling-out procedure when a protective member without an opening is used as another embodiment and only the protective member is pulled out after placement.

  The structure which attaches the drainage member 4 which consists of a three-dimensional network structure to the inner side surrounded by the web 3a and the flange 3b of the U-shaped steel sheet pile 3, and attaches the removable protective member 21 to the front side of the U-shaped steel sheet pile 3 Is the same as in the case of FIG. 9, and in this embodiment, a grooved steel 21 e without an opening is used as the protective member 21.

  When placing the U-shaped steel sheet pile 3, the tip of the grooved steel 21e as the protective member, that is, the lower end, is attached to the tip mounting member 5 by spot welding 26 or the like with the drainage member 4 covered with the protective member 21. It is simply joined (see FIG. 9 (a)).

  A gripping piece 24 is welded 25 to the upper end of the grooved steel 21e having no opening as the protective member 21. After placing, the gripping piece 24 is gripped by a chuck of a drawing machine or the gripping piece. And a wire or the like is passed through the hole, and only the protective member 21 is pulled up (see FIG. 9B).

  By completely pulling out the channel steel 21e, only the U-shaped steel sheet pile 3 and the drainage member 4 remain in the ground, and there is no possibility that the protection member 21 impedes drainage efficiency (see FIG. 9 (c)).

  FIGS. 11A and 11B are explanatory diagrams regarding a mounting area ratio of the drainage member to the sheet pile wall, where FIG. 11A is a plan view and FIG. 11B is a front view.

  As mentioned above, since liquefaction is likely to occur in loose sandy ground where the pore water at a depth of about 20m or less from the ground surface is saturated, drainage members for liquefaction countermeasures also depend on the local ground. What is necessary is just to attach to the range required with respect to the layer determined to be a liquefied formation layer.

  Also, considering the installation cost, ease of construction, drainage efficiency, etc., the drainage efficiency is analytically calculated as the width of the sheet pile wall and the width of the drainage section in the direction of the sheet pile wall (the sum of the widths of multiple drainage sections). It is reasonable to think that it is related and limited to that scope.

  From such a viewpoint, FIG. 11 tries to perform analysis based on the projected area of the drainage portion of the drainage member with respect to the projected area of the sheet pile wall.

The projected area of the drainage part of the drainage member relative to the projected area of the sheet pile wall to be obtained here (drainage member attachment area ratio R _A ) is referred to with reference to FIG. 11, and R _A = (2 × c × d) / (a Xb).

In consideration of cost, ease of construction, drainage efficiency, etc., this _RA is preferably 10% or more, and more preferably 20% or more when the projected area of the drainage is 100%. Compared with, drainage function comparable to that can be demonstrated.

  The sheet pile with drainage function of the present invention is a subterranean structure such as an underpass, a sand basin, a joint ditch, a cave, a river levee, a dam, a railroad embankment, a railroad in a ground where liquefaction may occur during an earthquake. It can be used as a liquefaction countermeasure wall, seismic reinforcement wall, or a retaining wall, revetment, quay, etc., provided for stabilization of embankment-like structures such as retaining walls and roads.

DESCRIPTION OF SYMBOLS 1 ... Sheet pile wall, 2 ... Hat-shaped steel sheet pile, 2a ... Web, 2b ... Flange, 3 ... U-shaped steel sheet pile, 3a ... Web, 3b ... Flange, 4 ... Drainage member (three-dimensional network structure), 4a ... Dense 4b ... hollow portion 4d ... core material 4e ... core material 5 ... tip mounting member 6 ... rear end mounting member 7 ... drainage member protection plate,
DESCRIPTION OF SYMBOLS 21 ... Protection member, 21a ... Perforated channel steel, 21b ... Punching metal, 21c ... Welded wire mesh, 21d ... Hole punching plate, 21e ... Channel steel, 22 ... Small hole, 23 ... Locking member, 24 ... Holding piece 25 ... Welding, 26 ... Spot welding

Claims (10)

  In the sheet pile with drainage function, which is formed by integrating a drainage member made of a resin solid network structure extending in the longitudinal direction of the sheet pile main body into a sheet pile main body that is placed in the soil or in water to constitute a wall body, the drainage member A sheet pile with a drainage function, characterized in that the net structure in the vicinity of the surface is denser than the inner net structure.   The sheet pile with drainage function according to claim 1, wherein the interior of the drainage member is hollow.   The sheet pile with drainage function according to claim 1 or 2, wherein at least a part of the drainage member is joined to a sheet pile main body.   The sheet pile with a drainage function according to claim 1, 2, or 3, wherein an area ratio of a gap in a network structure in the vicinity of the surface of the drainage member is 4% or more.   5. The sheet pile with drainage function according to claim 1, wherein the drainage member is attached to one or both sides of the sheet pile main body on one or a plurality.   The outer surface of the drainage member and / or when the interior of the drainage member is hollow, the inner surface of the hollow side is covered with a filter. Sheet pile with drainage function.   The said drainage member is protected by the protection member, The sheet pile with a drainage function as described in any one of Claims 1-6 characterized by the above-mentioned.   The sheet pile with drainage function according to claim 7, wherein the protection member is a protection member having an opening ratio of 4% or more.   The sheet pile with drainage function according to claim 7 or 8, wherein the protection member is detachable from the sheet pile body or the drainage member. It is a sheet pile wall which connects many sheet piles with a drainage function as described in any one of Claims 1-9, Comprising: With respect to the projection area of the said sheet pile wall, the drainage part of the drainage member attached to one side A sheet pile wall with a drainage function, wherein the projected area is 8% or more.

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