JP5782734B2 - Wall sheet with liquefaction measures and steel sheet pile with liquefaction suppression function - Google Patents

Description

  The present invention provides a wall for providing liquefaction countermeasures such as embankment-like structures, various underground structures, revetments, etc., provided on or in a ground where liquefaction may occur during an earthquake, and the wall The present invention relates to a steel sheet pile having a liquefaction inhibiting function that can be used in the manufacturing process.

  In landfills and other grounds where liquefaction may occur during earthquakes, drainage materials with drainage function can be placed in the ground, or drainage members can be attached to sheet piles or piles as countermeasures for liquefaction. Various technologies have been developed to suppress liquefaction by dissipating excess pore water pressure through these drainage members during an earthquake (see, for example, Patent Documents 1 to 7).

  In addition, as for the sheet pile wall as a revetment, in order to prevent the flow of groundwater from being blocked by the sheet pile wall and damaging the natural environment of the waterside, a sheet pile wall body provided with a water permeable hole is known. (For example, refer to Patent Document 8).

  In addition, Patent Document 9 describes a steel sheet pile for liquefaction countermeasures in which a water passage hole is provided in the sheet pile main body to induce and dissipate excess pore water pressure during a earthquake into a hollow drainage member. Has been.

JP-A-55-142815 Japanese Utility Model Publication No. 56-116434 Japanese Patent Publication No. 06-011990 Japanese Patent Laid-Open No. 11-158862 Japanese Patent Laid-Open No. 02-225712 JP-A-10-168868 Japanese Patent Laid-Open No. 11-117284 JP 2003-336252 A JP 09-242100 A

  As described in the background art section, when installing a liquefaction countermeasure wall on embankment, revetment, etc., as shown in FIG. 8, for example, a number of steel sheet piles attached with drainage members 33 for liquefaction suppression 32 are connected via a joint to construct the wall body 31. When the wall body 31 is provided on the ground 34 having high water permeability, the smooth flow of groundwater is obstructed at all times. At this point, there is a risk that the water level will drop in the form as shown in the right side of the figure.

  Also, as described in the background section, the sheet pile wall body is not designed to prevent liquefaction, but to prevent the groundwater flow from being blocked by the sheet pile wall and damaging the natural environment of the waterside. The one with holes is known, and it always serves its purpose, but when liquefaction occurs during an earthquake, the sand behaves like a fluid, so the earth and sand flows out from the water-permeable hole to the other side of the wall. The effect of liquefaction countermeasures will be significantly reduced.

  As an example, when a wall body without drainage function and water permeability is provided at the bottom of the embankment, when the ground is liquefied, the excess pore water pressure of the embankment side ground is higher than that of the ground opposite to the embankment due to the overload pressure of the embankment Since it is high, the earth and sand moves from the embankment side to the opposite side through the water-permeable holes in the wall. At the same time, the earth and sand also flows to the opposite side of the embankment through the opening, so that the embankment can sink greatly.

  As another example, a case is assumed where a wall body having an opening without a drainage function is installed as a protection measure for underground structures. Underground structures (such as underground underground trenches buried in the ground) are susceptible to floating damage when the ground is liquefied, so as a countermeasure against this, install walls on both sides of the structure to close the ground. It is effective to prevent the earth and sand from going around the structure.

  However, if the permeable holes are simply provided in the wall body, the excess ground water pressure is higher on the outer ground of the wall than on the structure-side ground, so the earth and sand opens from the outer side of the wall to the underground structure side. It moves through the part and can cause the structure to rise.

  The present invention is intended to solve such problems, and is highly liable to liquefaction during an earthquake, and in a ground having a sand layer with good water permeability at all times, while providing a drainage function for liquefaction suppression, An object of the present invention is to provide a wall body and a steel sheet pile provided with a water permeable hole for reducing the hindrance to the groundwater flow.

The wall body subjected to the liquefaction countermeasure according to claim 1 of the present application is made of a steel sheet pile arranged continuously in the wall direction, and the drainage member is a continuous wall body attached with a drainage member for suppressing liquefaction on at least one side. consists groove shape steel having an attached water passing holes on the steel sheet pile body, is provided with an opening for permeability of groundwater in normal times in the steel sheet pile body, steel sheet pile body of the drainage member said opening Outside the installation range, the drainage member is provided in a zigzag shape, and the drainage member is joined to the steel sheet pile main body by welding, thereby reducing the strength due to the cross-sectional defect of the steel sheet pile main body due to the opening. It is characterized by supplementing .

  The wall body that is the subject of the present invention is most commonly a steel sheet pile wall, and a large number of steel sheet piles are connected by joints formed at both ends of the steel sheet pile, and embankment, liquefaction of underground structures A wall for countermeasures or a wall as a revetment or quay is constructed.

In the case of steel sheet piles, U-shaped steel sheet piles, hat-shaped steel sheet piles that can be connected in the same direction by left and right asymmetric joints, Z-shaped steel sheet piles, linear steel sheet piles, their combined steel sheet piles, lightweight steel sheet piles, or H-shaped steel and hats combination sheet pile of shaped steel sheet pile, or a combination sheet pile which combines H-beams and SM-J pile (trade name), there is a steel sheet pile, etc., have such limited.

Liquefaction is relatively loose sand soil and sandy land Release of interstitial water saturation at a depth of within about 20m from the ground, or silty sand soil, likely occur in Tsubute混Ri sandy soil, etc. Also, drainage members for liquefaction measures may be attached within a high risk of liquefaction according to the local ground. It is also efficient to provide the opening in a highly permeable layer with a groundwater flow. Since ground with high risk of liquefaction is generally ground with high water permeability, the attachment range of the drainage member and the range in which the opening for water permeability is provided are often almost the same.

  At all times, the wall body is formed with a water-permeable opening so that the smooth flow of groundwater is not hindered. Solved.

On the other hand, in the event of an earthquake, as with conventional liquefaction countermeasures, excess pore water pressure is dissipated through the drainage members on the surface of the wall or in the vicinity, and liquefaction of the ground around the wall is suppressed, and the soil that constitutes the ground is muddy water. It does not become a shape. Therefore, the earth and sand flows out from the opening to prevent the liquefaction countermeasures, as in the case where only the opening is provided in the sheet pile wall in order to prevent the flow of groundwater from being blocked and the natural environment of the waterside from being damaged. fear not name, such as causing lost.

If drainage member is attached to the wall body, liquefaction deterrent at wall position is ensured, also it is efficient at hitting設作industry to transport and ground.

  The drainage members need not all be attached to the wall body body, and some of them may be placed away from the wall body body in the ground. It becomes possible.

  Claim 2 is a wall body to which countermeasures against liquefaction according to claim 1 are applied, wherein the steel sheet pile is a hat-shaped steel sheet pile or SM-J pile that can be connected in the same direction by a left-right asymmetric joint, and the opening portion is It is provided in a flange or a web.

In wall subjected to liquefaction measures according to 請 Motomeko 1 or 2, wastewater member ing from the groove-shaped steel having a water-passing hole which is attached to a steel sheet pile body.

  Since the highly rigid groove-shaped steel material is integrated with the steel sheet pile main body as a drainage member, it is easy to place and has an effect of compensating for strength reduction due to the opening of the steel sheet pile main body.

Claim 3 is a wall body to which countermeasures against liquefaction according to claim 1 or 2 are applied, wherein a part of the opening is provided within an installation range of the drainage member on the wall body, whereby the drainage member It is also possible to drain water from the opening through the opening.

  By connecting the drainage member and the opening of the wall body, excess pore water pressure at the time of the earthquake is dissipated from the opening of the wall body, and the ground on the side opposite to the ground where the drainage member is attached is also liquefied. It can be deterred and liquefaction deterrence can be made more efficient.

  When the drainage member is a perforated groove-shaped steel material, and the wall body body and the groove-shaped steel material form a drainage channel for preventing liquefaction, and the wall body body opening is provided in the grooved steel mounting width range, the opening In addition, it is recommended to take measures such as attaching a filter to prevent the invasion of sediment during liquefaction. As a result, maintenance of water permeability at all times can be achieved, and liquefaction on both sides of the wall body can be suppressed during an earthquake, which is efficient.

In the wall body which applied the countermeasure against liquefaction concerning Claim 4 , Claim 1, 2, or 3 , The total of the area of the said opening part was made into 0.1 to 2% of a wall body projected area. It is a feature.

  The ratio of the total area of the openings to the wall projection area (opening ratio) is preferably the minimum necessary to prevent the strength of the wall body made of steel sheet piles, etc., and the necessary water flow rate. It is necessary to ensure.

  If the aperture ratio is increased, the flow rate ratio before and after the wall body installation is large and there are few obstacles, but the cross-sectional performance of the wall body is degraded. A range in which the flow rate ratio is large and the deterioration of the cross-sectional performance is not large is preferable.

  As shown in FIG. 8, if the opening ratio is about 0.1 to 2% or less, about 70 to 95% of the water permeation flow rate can be secured if the ground is suitable for application of the steel sheet pile of the present invention.

  By setting the aperture ratio to 0.1% or more, although depending on the conditions, it is possible to secure a minimum of about 70% to which the flow rate ratio can be applied. Furthermore, by setting the aperture ratio to within 2%, the section modulus of the steel sheet pile can generally be secured at 70% or more, and the secondary moment of section can be secured at 95% or more. Economic burden due to weight increase due to up can be minimized.

  An even more preferable range is a normally required flow rate ratio before and after wall installation of 85% or more, and a decrease in cross-sectional performance due to opening (a cross-section coefficient of 85% or more can be secured and a secondary moment of section). Is 95% or more), and the aperture ratio is within a range of 0.3 to 1%.

  The position of the opening is generally a position corresponding to a water-permeable layer of the ground.

  The hole shape of the opening is not particularly limited, such as a circular shape, a rectangular shape, a long hole, and a plurality of continuous holes. However, if the target permeable ground has uniform water permeability (that is, uniform ground), the water permeability It is preferable that the hole area of each hole and the opening pitch between the holes are substantially the same so that the property is ensured uniformly.

The steel sheet pile having a liquefaction suppression function according to claim 5 is a steel sheet pile in which a drainage member for liquefaction suppression is attached to at least one side, and the drainage member has a water passage hole attached to the steel sheet pile main body. consists groove shape steel, is provided with an opening for permeability of groundwater in normal times in the steel sheet pile body, at least a portion of said opening is outside the installation range to the steel sheet pile body of the drainage member, the drainage member In addition, the drainage member is joined to the steel sheet pile main body by welding to compensate for the strength reduction due to the cross-sectional defect of the steel sheet pile main body due to the opening. Monodea Ru.

Steel sheet pile having a liquefaction suppression function according to the 請 Motomeko 6, in the steel sheet pile according to claim 5, wherein the steel sheet pile is hat-shaped steel sheet pile or SM-J pile can be connected in the same direction by asymmetrical joint It is characterized by this.

It steel sheet pile having a liquefaction suppression function according to claim 7, in which the steel sheet pile according to claim 5 or 6, is provided with a portion of the opening in the installation range of the steel sheet pile body of the drainage member It is characterized by.

  This is because at least a part of the opening is overlapped at the installation position of the drainage member on the steel sheet pile main body, so that the pore water in the ground opposite to the drainage member mounting side is discharged through the opening of the steel sheet pile main body. It is possible to prevent liquefaction.

A steel sheet pile having a liquefaction inhibiting function according to claim 8 is the steel sheet pile according to claim 5, 6 or 7 , wherein the total area of the openings is 0 of the projected area of the steel sheet pile located in the openings. Ru der which is characterized in that as a .1～2%.

請 steel sheet piles according to Motomeko 5-8, in addition to being able to prevent liquefaction of the wall on both sides of the ground efficiently while providing a constant water permeability, the steel as high groove shape steel drainage member rigidity since integrated with sheet pile body, two lifting the effect of compensate strength reduction due to the opening of the steel sheet pile body with a easy pouring.

The flat at all times, that the opening for water flow to the wall body is formed, without smooth flow of ground water is inhibited, conventionally, wither wells in the wall behind it has been a problem and the drawdown there is no problem.

  On the other hand, at the time of an earthquake, like the conventional liquefaction countermeasures, excessive pore water pressure is dissipated through the wall surface or the drainage member in the vicinity, and liquefaction of the ground is suppressed. Therefore, the flow of groundwater is simply cut off, and soil and sand flow out from the opening to reduce the effect of liquefaction countermeasures, as in the case where an opening is provided in the sheet pile wall to prevent damage to the natural environment of the waterside. There is no fear of letting it go.

It is a vertical sectional view for explaining the outline and function of the wall body to which the liquefaction countermeasure of the present invention is applied. It is a perspective view of a steel sheet pile in the actual Example 1. It is a perspective view of a steel sheet pile in the real施例2. Shows a steel sheet pile in the real施例3 is a perspective view seen from (a), (b) the opposite sides. Shows a modification of the steel sheet pile in the real施例3, (a) is a perspective view of the case of the staggered across the drain member opening, (b) further openings in triplicate hole FIG. The example of a steel sheet pile and a drainage member is shown, (a) is a horizontal sectional view, (b) is an elevation view. It shows an example of a steel sheet pile and drainage member, (a) is a horizontal sectional view, (b) is an elevation view, (c) is a perspective view of a steel sheet pile, (d), (e) is a drainage member A cross-sectional view is shown. It is a vertical sectional view for explaining an outline and a function of a wall body to which a conventional liquefaction countermeasure is applied as a comparative example. The relationship between the wall opening ratio and the flow ratio before and after wall installation in a general ground was obtained. (A) is an analysis model, and (b) is the opening ratio and flow ratio before and after wall installation. It is a graph which shows the relationship.

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

Figure 2 is a perspective view of a steel sheet pile 11 in the actual Example 1, steel sheet pile comprising a possible hat-shaped steel sheet pile connected in the same direction by the asymmetric joints in Example 1 or SM-J Pyle (trade name) The sheet resin 13a constituting the drainage member is attached to the inside surrounded by the 11 body web 11a and the flange 11b, and a large number of water permeable holes 12 are formed in the steel sheet pile 11 body web 11a.

  By placing such a steel sheet pile 11 in the ground while fitting the joints 11c and 11d on both the left and right sides, a steel sheet pile wall with a countermeasure against liquefaction in the ground is constructed.

  The planar resin material 13a has a water passage inside, and a sheet-like filter is attached to the outer surface as necessary, and a hole, a welded wire mesh or expanded metal, A protective member made of a net-like resin material or the like is attached.

  FIG. 1 is a vertical cross-sectional view for explaining the outline and function of a wall body to which liquefaction measures of the present invention are applied, and by providing a water permeable hole 12 in a web 11a of a steel sheet pile 11 body, The smooth flow of groundwater is not hindered, and there is no problem of well drainage and water level drop behind the wall, which has been a problem in the past.

On the other hand, at the time of earthquake, the drain member 3 Through, excess pore water pressure is dissipated, ground liquefaction is suppressed.

  Since the functions and principles of the present invention shown in FIG. 1 are the same in the second embodiment and later, which will be described later, repeated description will be omitted in the second and subsequent embodiments.

  In the first embodiment, since the water permeable holes 12 are also provided at the mounting position of the planar resin material 13a, the excess pore water pressure during an earthquake can be dissipated through the water permeable holes 12 as well.

Figure 3 is a perspective view of a steel sheet pile in the real施例2, inside surrounded by the web 11a and flange 11b of the steel sheet pile 11 body of hat-shaped steel sheet pile also in Example 2, constituting the drain member A sheet-like resin material 13 a is attached, and a large number of water-permeable holes 12 are formed in the web 11 a of the steel sheet pile main body 11.

  The point which attaches a sheet-like filter to an outer surface as needed, or attaches a protection member to the outer surface is the same as that of the case of Example 2.

  In Example 2, the water permeable hole 12 is not provided at the attachment position of the planar resin material 13a, but instead the water permeable hole 12 is also formed in the flange 11b portion of the steel sheet pile 11 main body.

FIG. 4 shows a steel sheet pile in the real施例3 is a perspective view seen from (a), (b) the opposite sides.

  The drainage member in Example 3 is made of a groove-shaped steel material 13b having a water passage hole 14 with a filter, and in the event of an earthquake, an internal hollow space in which excess pore water is surrounded by the steel sheet pile 11 body and the groove-shaped steel material 13b. It enters the space, the excess pore water pressure is dissipated, and liquefaction is suppressed.

  Moreover, normally, the flow of groundwater is ensured by the water-permeable holes 12 formed on both sides in the width direction of the web 11a portion of the steel sheet pile 11 body.

  FIG. 5 (a) is a modified example of the steel sheet pile according to the third embodiment, in which openings are provided so as to be staggered with a drainage member interposed therebetween. Thus, if it opens like a zigzag shape on both sides of a drainage member, since the cross-sectional defect | deletion of a steel sheet pile main body does not concentrate on the same height, it is suitable. Moreover, if the groove-shaped steel material is joined to the steel sheet pile main body by welding or the like in the opened cross-sectional defect portion, the steel sheet pile is reinforced, and the strength reduction due to the cross-sectional defect can be compensated.

  Therefore, if the drainage member is integrated with the steel sheet pile body by welding, etc., and if the opening is provided in the drainage member mounting section, it is possible to suppress the liquefaction with minimum strength and ensure the necessary water permeability. Moreover, the steel sheet pile and wall of the present invention can be provided.

  FIG. 5B shows a case where a plurality of openings in the drainage member mounting section are connected, for example, three continuous holes, as another modification. Depending on the type and model of the steel sheet pile, there is a problem because if the web is narrow and one hole is required to secure the required area, the long hole and the rectangular hole will have a long hole length and will require both labor and cost. A plurality of (three in this example) circular holes that are mechanically easy to open are connected in series. By this method, one hole can be substantially enlarged, and the labor for opening can be reduced.

  4 and 5, the steel sheet pile main body may be any type such as a U-shaped steel sheet pile and a hat-shaped steel sheet pile.

FIG. 6 shows an example of a steel sheet pile and a drainage member, where (a) is a horizontal sectional view and (b) is an elevational view.

  In this example, as a drainage member, a resin-made three-dimensional network structure 23a having a filter function on the outer peripheral surface, for example, a filter is placed around the three-dimensional network structure, and the web 21a and flange of the U-shaped steel sheet pile 21 main body. A large number of water permeable holes 22 communicating with the inside of the three-dimensional network structure 23a are formed in the web 21a of the U-shaped steel sheet pile 21 main body while being attached to the inside surrounded by 21b.

  The three-dimensional network structure 23a is covered with a protective metal mesh 23b. Further, the protective wire mesh may be a protective plate having a large number of holes, a cylindrical body, or the like.

FIG. 7 shows another example of the steel sheet pile and the drainage member. (A) is a horizontal sectional view, (b) is an elevation view, and (c) is a perspective view of the steel sheet pile as seen from the drainage member mounting side. , (D) is a cross-sectional view of the three-dimensional network structure 25 (the mesh density of the network structure is dense on the outside; that is, the density is adjusted so as to have a function of preventing intrusion of earth and sand; the inside is sparse; (E) is a cross-sectional view of a three-dimensional network structure (having a filter function to prevent the sand and sand from entering the drainage member on the outside of the network structure and having a hollow portion on the inside). is there.

  In this example, as a drainage member, a three-dimensional network structure 25 made of a resin having a mesh structure on the surface side that is denser than the inner network structure on the peripheral surface and having a filter function on the peripheral surface is used as a hat-shaped steel sheet pile. 24 is attached to the inside surrounded by the web 24a of the main body and the flange 24b, and a plurality of water-permeable holes (openings) 22 communicating with the inside of the three-dimensional network structure 25 are formed in the web 24a of the hat-shaped steel sheet pile 24 main body. It is.

  In such a structure, the network structure around the drainage member that has a filter function can eliminate practically no damage during steel sheet pile manufacturing, transportation, and placement on the ground, so it is easy to handle and environmentally friendly. It is possible to provide a steel sheet pile having a function to suppress the crystallization.

  In this way, the three-dimensional network structure 25 incorporating the filter function on the outer peripheral surface side is protected on the surface as long as the surroundings are resistant to friction and retain the liquefaction suppression function and do not substantially damage even if placed on the ground. There is no need to cover the material.

  However, in the case where the steel sheet pile 24 of this example is placed on the ground mixed with hard and sharp crushed stone, a part of the periphery of this special network structure or the ground surface side is made of a metal mesh, a perforated plate or a perforated plate. It may be protected by a cylindrical body, or a filter such as a resin or non-woven fabric that is different from the network structure may be provided around the network structure 25, and the protective material as described above may be installed outside the filter.

  The drainage member 25 in this example has a net-like structure on the surface side that is denser than the inner mesh-like structure over the peripheral surface, and has a drainage part outer periphery side filter function. It is only necessary to have a dense mesh layer on the outside, which has a filter function that prevents intrusion inside and dissipates excess pore water pressure of the ground, and the inside of this layer with this filter function is the outer layer What is necessary is just to make it less sparse and to reduce the resistance to movement of the pore water in the ground.

  The order of this sparseness / sparseness may gradually become sparse as it goes inward, and there may be a dense layer in the middle and sparse inside (eg, sparse on the outermost side). It may be a structure. In short, in a three-dimensional network structure as a drainage member, in order to suppress the intrusion of earth and sand from the outside, the drainage member outer side is made denser to have a filter function, and the inside of the member has a sparse space, that is, the movement resistance of water. It is sufficient if a small space can be secured.

  In an extreme case, as shown in FIG. 7 (e), the inner side of the drainage member 25b may be hollow. If the inner side is hollow, the drainage resistance is reduced, so that the liquefaction suppression function is excellent. In this case, the pressure resistance is slightly lowered, but practically no problem.

  In addition, regardless of the structure of the drainage member having a liquefaction suppression function, having a hollow part inside the drainage member increases the liquefaction suppression function when the liquefaction is less due to drainage resistance above the ground. In addition, it is possible to dissipate the water pressure promptly and always alleviate the adverse effects on the steel sheet pile wall even in the case of the back ground or the front ground with the pressurized water layer.

  In this example, since the opening of the steel sheet pile main body is provided in the installation range of the drainage member 25 to the steel sheet pile main body, the liquefaction in the direction opposite to the drainage member 25 installation side ground can also be suppressed as shown in FIG. Same as example.

  Moreover, normally, the ground water permeability to the opposite ground can be maintained from the opening of the steel sheet pile main body through the drainage member.

  Regarding the cross-sectional shape of the drainage member (three-dimensional network structure) shown in Fig. 7 (d) or (e), the outer side is rectangular and the height is too high from the viewpoint of processing and transportation, and from the ease of placing on the ground. Nothing is good. As shown in FIG. 7 (c), in order to prevent damage to the drainage member and to penetrate into the ground, measures such as attaching the drainage member protective material may be taken while devising the processing of the tip.

  In addition, the sheet pile having the drainage member 25 is not particularly limited, such as a U-shaped steel sheet pile, a Z-shaped steel sheet pile, a linear steel sheet pile, a lightweight steel sheet pile, and a concrete sheet pile. In addition, as shown in FIG. 7, all or a part of the openings provided in the sheet pile body may be provided in a predetermined area ratio within the drainage member attachment range, and conversely, provided in a predetermined area ratio outside the drainage member attachment range. May be.

  In the case of a steel sheet pile retaining wall that requires constant drainage from the ground even under conditions where the ground is not liquefied, a rectangular shape with a filter function that prevents intrusion of soil and sand, as in this example. When a three-dimensional network structure is attached to the back ground side in contact with the steel sheet pile main body, and the opening of the steel sheet pile main body is provided within the attachment range, the opening does not have a filter attached to the water from the opening. The drainage can be stopped, the escape of earth and sand from the opening can be stopped, and the drainage member having a large projected area efficiently collects water from the back ground, so that a suitable steel sheet pile retaining wall can be provided.

  Next, the area of the opening will be described. FIG. 8 shows the influence of the opening ratio of the wall body on the flow rate ratio before and after installing the wall body in a certain general ground.

  Not only the aperture ratio but also the wall thickness (steel sheet pile) affects the flow rate ratio. However, the thickness of the steel sheet pile is usually 50 mm or less, and in order to ensure a flow rate of 70% or more of the flow rate when the wall body is not provided, which is a range in which a large hindrance is not normally caused in normal water permeability. The aperture ratio is preferably 0.1% or more of the wall area (projected area).

  More preferably, the aperture ratio should be 0.3% or more so that the flow rate ratio can be secured to 0.85 or more. When the aperture ratio is 2%, the flow rate ratio is 0.95 or more, and even when the aperture ratio is higher than that, the rate of increase in the flow rate ratio tends to be small and converge to a constant value.

  The liquefaction-preventing wall body and steel sheet pile with liquefaction suppression function according to the present invention are used for liquefaction countermeasures such as embankments, dams, retaining walls, etc. on the ground where liquefaction may occur during an earthquake. ), Or underpass, digging roads, underground tunnels, water and sewage facilities including sand basins, waterways, pumping and drainage station facilities, tunnels, underground structures such as underground pipes, revetments, quay walls, etc. be able to.

DESCRIPTION OF SYMBOLS 1 ... Wall body, 2 ... Steel sheet pile, 3 ... Drainage member, 4 ... Ground in danger of liquefaction, 5 ... Embankment,
11 ... Steel sheet pile, 11a ... Web, 11b ... Flange, 11c, 11d ... Joint,
12 ... Water-permeable hole (opening), 13a ... Planar resin material, 13b ... Groove-shaped steel material, 14 ... Water passage hole with filter,
21 ... U-shaped steel sheet pile, 21a ... Web, 21b ... Flange, 21c, 21d ... Fitting,
22 ... Water-permeable holes (openings), 23a ... Three-dimensional network structure, 23b ... Protective wire mesh,
24 ... Hat-shaped steel sheet pile, 24a ... Web, 24b ... Flange, 25 ... Three-dimensional network structure of the present invention, 25a ... Three-dimensional network structure of the present invention (three-dimensional network structure outer dense (with filter function), inner dense ), 25b ... the three-dimensional network structure of the present invention (the three-dimensional network structure has a filter function on the outside and a hollow portion on the inside),
31 ... Wall body, 32 ... Steel sheet pile, 33 ... Drainage member, 34 ... Ground with high water permeability, 35 ... Embankment

Claims (8)

In a continuous wall body comprising steel sheet piles arranged in a wall direction and having a liquefaction-suppressing drainage member attached to at least one surface, the drainage member is made of a groove-shaped steel material having water passage holes attached to the steel sheet pile body. The steel sheet pile main body is provided with an opening for water permeability of groundwater in normal times, and at least a part of the opening is staggered across the drainage member outside the installation range of the drainage member on the steel sheet pile main body. A liquefaction countermeasure characterized in that the drainage member is joined to the steel sheet pile main body by welding to compensate for strength reduction due to a cross-sectional defect of the steel sheet pile main body due to the opening. Wall body which we gave.   2. The liquefaction countermeasure according to claim 1, wherein the steel sheet pile is a hat-shaped steel sheet pile or SM-J pile that can be connected in the same direction by a left-right asymmetric joint, and the opening is provided in a flange or a web. Wall body given. A portion of the opening, by providing within the installation range of the wall body of the drainage member, according to claim 1 or 2, characterized in that you have allow drainage through the opening from the drainage member Wall body with the liquefaction countermeasures described. The wall body subjected to liquefaction countermeasures according to claim 1, 2 or 3, wherein the total area of the openings is 0.1 to 2% of the projected area of the wall body. In the steel sheet pile to which a drainage member for suppressing liquefaction is attached on at least one side, the drainage member is made of a groove-shaped steel material having a water passage hole attached to the steel sheet pile main body, and the steel sheet pile main body in normal groundwater And at least a part of the opening is provided outside the installation range of the drainage member on the steel sheet pile main body so as to have a staggered shape with the drainage member interposed therebetween, and the drainage member. A steel sheet pile having a liquefaction suppression function characterized in that, by joining the steel sheet pile body by welding, the strength reduction due to a cross-sectional defect of the steel sheet pile body due to the opening is compensated . 6. The steel sheet pile with anti-liquefaction measures according to claim 5, wherein the steel sheet pile is a hat-shaped steel sheet pile or SM-J pile that can be connected in the same direction by a left-right asymmetric joint. The steel sheet pile having a liquefaction inhibiting function according to claim 5 or 6 , wherein a part of the opening is provided within a range of installation of the drainage member on the steel sheet pile main body. The liquefaction suppression function according to claim 5, 6 or 7 , wherein the total area of the openings is 0.1 to 2% of the projected area of the steel sheet pile located in the openings. Steel sheet pile with

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