JP2013163901A - Formation method of steel plate underground partition wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a formation method of a steel plate underground partition wall, which can be executed at a low cost on a site of a small-scale building.SOLUTION: A plurality of steel plate members 11 having a prescribed dimension in a horizontal direction and a prescribed length in a vertical direction are forcibly fitted underground successively so that side edges are mutually connected with adjacent steel plate members. The steel plate member includes a body part 11a for which a steel plate is bent, and a steel pipe 11b attached to the body part, and the steel plate member is forcibly fitted underground while supplying water from an upper part of the steel pipe and discharging the water from a lower end. Also, the steel pipe may be prepared separately from the steel plate member so that a position in the horizontal direction of the steel pipe is restrained by the steel plate member and they are forcibly fitted together. Further, a distal end of the steel plate member may be wound around a distal end of a highly rigid stiffening member and folded upwards to be forcibly fitted into soil together with the stiffening member. The stiffening member can be pulled out upwards after the steel plate member is forcibly fitted.

Description

  The present invention relates to a method of forming a steel plate underground partition so as to press-fit a steel plate under the ground surface and partition the ground.

In sandy ground with a high groundwater level, it is known that liquefaction is likely to occur during an earthquake, and various countermeasures have been proposed. For example, there are those described in Patent Document 1 and Patent Document 2.
The structure described in Patent Literature 1 penetrates the support pile of the building to the support layer, constructs a wall body on the outer peripheral portion of the building, and penetrates the wall body deeper than the liquefied layer. The above-mentioned wall body shall be constructed by a deep mixing agitation method using cement hardener, and deformation of the supporting pile that will be the foundation of the building by suppressing the ground from flowing laterally due to liquefaction of the ground during an earthquake Is to prevent.

  Moreover, the structure of patent document 2 constructs a steel sheet pile wall so that the circumference | surroundings of a building may be surrounded, and the lower part of the steel sheet pile is embedded in the support ground. Moreover, the restraint structure is provided in the upper part of the steel sheet pile wall so as to surround the steel sheet sheet pile continuously in the circumferential direction.

Japanese Patent Laid-Open No. 9-49239 JP 2002-167778 A

  The liquefaction of the ground has been studied mainly because it can cause serious damage to large buildings such as commercial facilities and apartment buildings, but even in small-scale buildings such as detached houses. Many damages such as uneven settlement have occurred. It is difficult to apply a conventionally proposed technique as a means of suppressing liquefaction damage in such a small-scale building. That is, if the site is narrow like a detached house, there is no room for installing facilities necessary for the deep mixing agitation method and the construction becomes difficult. Moreover, it is often difficult to drive a steel sheet pile, a steel pipe pile or the like that reaches the non-liquefied layer in a residential area. Furthermore, as a measure that can be implemented by the owner of a detached house, it must be avoided that the cost is high.

  Under such circumstances, as a partition wall provided so as to surround the ground directly under the small-scale building, it is conceivable that a steel plate member having a small cross section is press-fitted into the ground, and a plurality of these are connected to form a partition wall. If the steel plate member having a small cross section has a predetermined width and has an axis in the vertical direction, it can be press-fitted into the ground without using a large construction machine, and construction can be performed at low cost. However, in the steel plate member having a small cross section as described above, the bending rigidity in the axial direction becomes small, and there is a risk of buckling during press-fitting.

  The present invention has been made to solve the above-mentioned problems, and its object is to provide a method for forming a steel plate underground partition wall that can be constructed even on a small site and can be carried out at a low cost. It is to be.

  In order to solve the above-described problem, the invention according to claim 1 is configured such that a plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are connected to each other. The steel plate member has a portion whose horizontal cross-sectional shape is closed, and the closed portion is a tubular portion that is continuous in the vertical direction, and an upper portion of the tubular portion. A method of forming a steel plate underground partition wall is provided in which water is supplied from the bottom and the steel plate member is pressed into the ground while discharging water from the lower end.

In this method, when the steel plate member is press-fitted, water is supplied to the ground in the vicinity of the tip of the steel plate member via the tubular portion, and when it is an unsaturated sandy ground, water is filled in the gap between the sand particles. . In addition, pore water pressure rises in the sandy ground that is saturated below the groundwater level. And when a steel plate member is press-fitted from above, the pore water pressure further increases, and the meshing between the sand particles in the ground is easily released. Therefore, the ground is easily fluidized by pressing the steel plate member from above, and the steel plate member can be easily press-fitted with a small pressing force. Thereby, the compressive force which acts on a steel plate member is reduced, and the possibility of buckling is reduced.
The tubular portion may be formed by adding a tubular member such as a steel pipe to a steel plate, or may be formed by bending a steel plate into a tubular shape.

  According to a second aspect of the present invention, a plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are sequentially press-fitted into the ground so that adjacent steel plate members and side edges are connected to each other. The steel plate member has a tube holding portion whose cross-sectional shape is bent so as to be in contact with the outer peripheral surface of the tube member having an axis in the vertical direction and restrain the relative displacement in the horizontal direction of the tube member. And forming a steel plate underground partition wall by holding the tube member in the tube holding part of the steel plate member, supplying water from the upper part of the pipe member, and press-fitting the steel plate member into the ground while discharging water from the lower end. provide.

  In this method, similarly to the invention according to claim 1, when the steel plate member is press-fitted, the ground near the tip is easily fluidized by the supply of water, and the steel plate member can be easily press-fitted. Further, the position of the pipe member can be changed in the vertical direction while being held in the pipe holding portion. Therefore, it is possible to adjust the position of the tip of the pipe member so that the tip of the steel plate member protrudes substantially the same height or downward as the lower end of the steel plate member, and in a wide range in the ground near the tip of the steel plate member when the steel plate member is press-fitted. Water can be supplied. As a result, the sandy ground is more easily fluidized, and the press-fitting of the steel plate member is facilitated.

  According to a third aspect of the present invention, a plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are sequentially press-fitted into the ground so that adjacent steel plate members and side edges are connected to each other. The steel plate member has a folded portion that is bent so that the front end portion is folded upward, and the steel plate member is overlapped with a plate-shaped stiffening member made of steel, and the folded portion is A steel plate underground partition wall in which the stiffening member and the steel plate member are rolled and fitted to each other, press-fitted into the ground in a state where the stiffening member and the steel plate member are overlapped, press-fitted to a predetermined depth, and then pulled out. A forming method is provided.

  In this method, a stiffening member having a high bending rigidity can be superposed on a steel plate member during press-fitting and press-fitted as a member having a high rigidity. Therefore, most of the pressing force during press-fitting can be applied to the stiffening member, the compressive force acting on the steel plate member can be reduced, and buckling of the steel plate member can be prevented.

  The invention according to claim 4 is the method of forming a steel plate underground partition wall according to any one of claims 1 to 3, wherein the steel plate member is formed by bending a horizontal cross-sectional shape into a concave shape. The concave portion is elastically deformed so as to expand on both sides, and a shape holding member is fitted into the concave portion, and the state in which the elastic deformation is generated is maintained and the steel plate member is press-fitted into the ground. The shape holding member has a compressive strength that maintains the shape of the elastically deformed concave portion and presses the steel plate member into the ground, and maintains elastic deformation of the steel plate member by water absorption. The one that loses the compressive strength as much as possible is used.

  In this method, the steel sheet member is press-fitted into the ground in a state where the shape holding member is fitted in a portion where the horizontal cross-sectional shape of the steel sheet member is concave, and the shape holding member sufficiently absorbs water over time. Then, the shape maintaining member cannot maintain the elastic deformation of the steel plate member. For this reason, a steel plate member deform | transforms so that the dimension between both-sides edges may be reduced, and the side edge joined with the adjacent steel plate member displaces in the direction which separates both steel plate members. Thereby, the side edge part of the joined steel plate member can mutually be stuck, and it becomes possible to suppress that water flows on both sides of the steel plate underground partition.

  As described above, in the method of forming a steel plate underground partition according to the present invention, the steel plate underground partition that partitions the ground below the ground surface can be easily constructed within a narrow site at a low cost.

It is the schematic sectional drawing and schematic plan view which show the steel plate underground partition which can be formed with the method which concerns on this invention. It is the schematic perspective view which saw through the state under the ground surface of the steel plate underground partition shown in FIG. It is a top view which shows a part of steel plate underground partition shown in FIG. It is a steel plate member which comprises the steel plate underground partition shown in FIG. 1, Comprising: It is a perspective view of the steel plate member used with the method which is one Embodiment of this invention. FIG. 2 is a vertical sectional view showing a part of the steel plate underground partition wall shown in FIG. 1. It is the schematic which shows the state which press-fits the steel plate member which comprises a steel plate underground partition into the ground. It is a top view which shows the other example of the steel plate member which can be used with the method which concerns on this invention. It is a top view which shows the state which press-fits a steel plate member by the method which is other embodiment of this invention. It is a schematic sectional drawing which shows the state at the time of the press injection of the steel plate member shown in FIG. It is a perspective view which shows the state which press-fits a steel plate member by the method which is other embodiment of this invention. It is the front view and sectional drawing which show the state which press-fits the steel plate member and stiffening member shown in FIG. It is a top view which shows a state when press-fitting the steel plate member which has a tubular part with a stiffening member. It is the schematic which shows the state of making the steel plate member elastically deform and press-fitting, and the state of the steel plate member after press-fitting. It is the schematic which shows the other example of the state which produces elastic deformation and press-fits a steel plate member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view and a schematic plan view showing a steel plate underground partition wall that can be formed by the method according to the present invention. Moreover, FIG. 2 is the schematic perspective view which saw through the state under the ground surface of this steel plate underground partition.
This steel plate underground partition is formed so that the circumference | surroundings of the area | region which constructs buildings 1 such as a detached house may be surrounded. And the steel shielding board 3 is laid by the predetermined depth substantially horizontally in the whole region in the area | region enclosed by this steel plate underground partition 2. As shown in FIG. Further, the steel pile 4 is press-fitted to a position deeper than the steel plate underground partition wall 2 so as to be in contact with or close to the steel plate underground partition wall 2, and the steel pile 4 is inserted into the steel plate underground partition wall 2. Are provided at predetermined intervals in the horizontal direction.
The steel plate underground partition wall 2 is formed in a layer 6 which is easily liquefied, that is, a sandy ground having a high groundwater level, and may be provided to a depth reaching the layer 5 where liquefaction hardly occurs, but liquefaction is not necessarily easily generated. It does not have to reach the layer 5 and may remain in the layer 6 that is easily liquefied. For example, it can be an underground steel plate partition from near the ground surface to a depth of 2 m to 10 m. More preferably, the depth is 4 m to 10 m.

The steel plate underground partition 2 is formed by continuously joining a plurality of steel plate members 11 that are long in the vertical direction in the horizontal direction as shown in FIG. The said steel plate member 11 has the main-body part 11a formed by bending a steel plate with the bending line of an up-down direction, and the steel pipe 11b attached to this main-body part by welding. The main body 11a is formed by bending a steel plate having a thickness of about 0.4 mm to 6 mm, and more preferably a steel plate of about 2 mm to 5 mm. Further, the steel plate member is preferably a steel plate that has been subjected to anticorrosion processing by plating or the like, and in particular, a steel plate that has been subjected to hot dipping with an alloy of zinc, aluminum, and magnesium (for example, “High corrosion resistance” manufactured by Nisshin Steel Corporation). It is desirable to use a hot-dip plated steel sheet ZAM ", [" ZAM "is a trademark of Nisshin Steel Co., Ltd.], a steel sheet plated with an aluminum alloy, or the like.
The main body 11a of the steel plate member is provided with a joint processing portion 11c for joining with the adjacent steel plate member 11 along both side edges by bending. Further, the stiffening portion 11d having a mountain shape in the horizontal cross section is formed between both side edges by a vertical fold line, and the steel pipe 11b extends in the vertical direction, that is, the axis of the steel plate member along this portion. It is attached by welding in the direction.

  The joining processed portion 11c is provided so that the shape in the vicinity of both side edges in the horizontal cross section is axisymmetric with respect to the center line aa of the steel plate member 11. Then, as shown in FIG. 3A, bending is performed so that the vicinity of the side edge is folded back from the first surface side where the stiffening portion 11d protrudes in a convex shape to the second surface side where the stiffening portion 11d is concave. It has a processed engagement end 11e. The adjacent steel plate members 11-1 and 11-2 are joined so that the first surface and the second surface are alternately opposite to each other, and are folded back from the first surface side to the second surface side. The engaging ends 11e are engaged with each other, and are joined so that the bent inner surfaces come into contact with each other.

  As shown in FIGS. 3 and 4, the steel pipe 11b attached to the main body 11a of the steel plate member 11 has a circular cross section and is a concave surface of the stiffening portion 11d provided in the main body 11a. Are fixed along the tube to form a tubular portion. As this steel pipe 11b, for example, one having an inner diameter of about 10 mm to 50 mm can be used, and one having an inner diameter of about 15 mm to 30 mm is more preferably used. The welding for attaching the steel pipe 11b to the main body portion 11a may be performed so as to continue along the vertical direction, but may be performed by joining a limited range at every predetermined interval. And this steel pipe 11b is joined so that it may have the lower end surface 11f in the substantially same height as the lower end of the main-body part 11a, and the lower end surface 11f is opened below with the cut | disconnected cross-sectional shape. Moreover, it may be deformed so that the opening has a flat shape by applying a compressive force in the vicinity of the lower end of the steel pipe 11b. The upper end portion 11g of the steel pipe 11b is bent so as to be separated from the main body portion 11a, and water is supplied from the upper end toward the lower end.

  As shown in FIG. 3 (b), the corner 2a when the steel plate underground partition 2 is provided so as to surround the building 1 is a corner that is bent at a substantially right angle with a vertical fold line between both side edges. The steel plate member 12 for part can be used. The steel plate member 12 for the corner portion is also provided with a processing portion 12a for joining along both side edges, and is press-fitted so as to be continuous with the other steel plate members 11 so as to surround the building 1 so as to surround the building 1 A partition wall 2 can be provided.

The steel shielding plate 3 is formed so as to cover the entire area inside the steel plate underground partition wall 2 formed so as to surround the periphery of the building 1, and the steel plate member 11 forming the steel plate underground partition wall 2. , 12, and a steel plate having a thickness approximately the same as that of 12 is laid almost horizontally. The steel plates to be laid are strip-shaped, and adjacent steel plates are overlapped with each other with a predetermined width near the side edges.
The steel shielding plate 3 laid as described above is joined to the upper part of the steel plate member 11 constituting the steel plate underground partition wall 2 at the periphery. As shown in FIG. 5, the steel plate member 11 and the steel shielding plate 3 are joined by bending the peripheral portion of the steel shielding plate 3 upward and overlapping the steel plate member 11 constituting the steel plate underground partition wall 2. 21 and the nut 22.
Moreover, as shown in FIG. 3, the steel plate underground partition wall 2 has unevenness due to the cross-sectional shape of the steel plate member 11, and a gap is generated between the steel shield plate 3 and the steel shield plate 3. It is desirable that this gap be filled with mortar, rubber-like elastic member, viscoelastic sealing agent, etc. and sealed as much as possible.

  The foundation 1a of the building 1 is provided on the steel shielding plate 3, and leveling concrete or the like is spread on the steel shielding plate 3, and a reinforcing bar is placed on the concrete foundation 1a. Can be built. Outside the range where the foundation 1a is provided, the soil 7 is back-filled on the upper side of the steel shielding plate 3, and the steel shielding plate 3 is buried at a predetermined depth. Moreover, it is desirable to set the position of the upper end so that the upper part of the steel plate underground partition wall 2 to which the steel shielding plate 3 is joined is also buried below the ground surface.

  A steel pipe, H-shaped steel, or the like can be used as the steel pile 4 that is press-fitted in the substantially vertical direction along the steel plate underground partition wall 2 outside the steel plate underground partition wall 2. And it press-fits to the position deeper than the steel plate member 11 which comprises the steel plate underground partition 2. FIG. The depth at which the steel pile 4 is press-fitted does not necessarily need to be press-fitted so as to reach the layer 5 where liquefaction is unlikely to occur, but in this embodiment, liquefaction hardly penetrates through the layer 6 that is liable to liquefy. Press-fit to layer 5

  By providing such a steel plate underground partition, the lower ground of the building 1 is surrounded by the steel plate underground partition 2 and the steel shielding plate 3 on the upper surface and side surfaces, and the ground below the ground water and the building in the event of an earthquake. Is suppressed from flowing laterally. Further, even when liquefaction occurs, sand and the like are prevented from flowing upward and ejecting. Furthermore, the steel pile 4 press-fitted outside the range surrounded by the steel plate underground partition 2 is deformed so that the steel plate underground partition 2 swells outward due to the force of the ground to flow sideways. Suppress. Therefore, the building 1 is less likely to sink due to fluidization, and damage caused by liquefaction of the ground is reduced.

Next, it is one Embodiment of this invention, Comprising: The method to press-fit the said steel plate member in the ground and form a steel plate underground partition is demonstrated.
The steel plate members 11 constituting the steel plate underground partition wall 2 are sequentially press-fitted one by one, and are provided on one side edge of the previously press-fitted steel plate member 11-1 as shown in FIG. 3 (a). The joining processed portion 11c-1 and the one joining processed portion 11c-2 of the steel plate member 11-2 to be next press-fitted are aligned and press-fitted. And the steel plate member 11 is press-fitted one by one, and the steel plate underground partition is formed in the shape which planar view closed so that the building 1 may be enclosed.
The press-fitting of the steel plate member 11 is desirably performed at a position excavated from the ground surface to a predetermined depth, and the upper end of the steel plate underground partition wall 2 is desirably set to a predetermined depth from the ground surface.

  As shown in FIG. 6, press fitting of the steel plate member 11 is performed by lifting the steel plate member 11 vertically and applying a pressing force from the upper end to press it into the ground. At this time, the steel plate member 11 is made of a thin steel plate and is lightweight, and the length is about 4 m to 10 m. Therefore, it can press-fit with the small construction machine 31, and a big pile driving machine etc. are not required. The press-fitting is performed by applying a pressing force from above without driving or applying vibration.

  The main body 11a of the steel plate member is formed by bending a thin steel plate and has a small cross-sectional area and a small bending rigidity in the axial direction, that is, the vertical direction. For this reason, there exists a possibility that the steel plate member 11 may buckle when a pressing force is applied from above. On the other hand, the steel plate member 11 attaches the steel pipe 11b to the main body portion 11a to increase the bending rigidity, and supplies water into the ground near the tip of the steel plate member 11 and press-fits it. Water is supplied from the upper end 11g of the steel pipe 11b and discharged from the lower end of the steel pipe 11b into the ground. The water supply to the steel pipe 11b may be performed by connecting a hose from the water pipe to the upper end of the steel pipe 11b to supply the water, or by feeding under pressure.

  Thus, the resistance to press fitting is reduced by supplying water to the lower end of the steel plate member 11. That is, by supplying water to the ground near the lower end of the main body 11a, water is filled in the gaps between the sand particles in the sandy ground. And it is thought that the meshing between the sand particles is easily released by the pore water pressure, and the resistance to the press fitting of the steel plate member 11 is reduced. Therefore, the steel plate member 11 can be easily press-fitted without causing buckling.

  After the steel plate underground partition 2 is formed as described above, a plurality of steel piles 4 are similarly press-fitted into a position along the steel plate underground partition 2 and within the range surrounded by the steel plate underground partition 2. The steel shielding plate 3 is laid so as to cover, and the peripheral edge portion is coupled to the upper part of the steel plate underground partition 2 as shown in FIG. The foundation 11a of the building is formed by laying a leveled concrete on the steel shielding plate 3. The periphery of the foundation 11a is covered with a backfill soil 7 having a predetermined thickness. Therefore, the water pipe, the gas pipe and the like drawn into the building can be embedded above the upper end of the steel plate partition wall 2 and the steel shielding plate 3.

  In the method according to the present invention, the shape of the steel plate member is not limited to that shown in FIG. 3, and a steel plate member having another shape can be used. For example, as shown to Fig.7 (a), the steel plate member 13 from which the process parts 13a and 13b for joining provided along the both-sides edge differ from each other can be used. In this steel plate member 13, the first joining processed portion 13 a and the second joining processed portion 13 b of another steel plate member 13 of the same shape adjacent to each other can be joined to each other. When the steel plate member 13 having such a shape is used, the side surfaces of the steel plate member 13 having irregularities such as the stiffening portion 13c can be joined in the same direction, and the gap is reduced at the portion where the steel shield plate 3 is joined. can do.

Moreover, it replaces with adding the steel pipe 11b to the main-body part 11a which consists of a steel plate, and the steel plate member in this invention can use what formed the tubular part by the bending process of the steel plate. As shown in FIG. 7 (b), the stiffening portion 14a formed at the substantially central portion in the width direction of the steel plate member 14 has a cross-sectional shape closed in a loop shape. In the position 14b which closes in the closed shape, a tubular portion is formed that can be joined by welding to supply water downward from above.
Even when such a steel plate member 14 is used, water is supplied from above as in the case of using the steel plate member 11 shown in FIGS. 3 and 4 to reduce the resistance during press-fitting so that buckling does not occur. It becomes easy to press fit.

Next, another embodiment of the present invention will be described.
In this embodiment, as a structure for supplying water to the tip of the steel plate member when the steel plate member is press-fitted, the steel pipe 32 is not fixed to the steel plate member but at a position along the steel plate member 15 as shown in FIG. And press-fitting. In the steel plate member 15 shown in FIG. 8 (a), the width of the opening portion 15b on the side where the stiffening portion 15a provided at the central portion of the cross section in the horizontal direction is bent into an arc shape and the cross-sectional shape becomes concave. The inner diameter of the arcuate portion 15c is smaller. Therefore, the stiffening portion 15a functions as a tube holding portion, and the circular cross-section steel pipe 32 inserted inside the arc-shaped portion can be held and press-fitted together. The steel pipe 32 can move relative to the steel plate member 15 in the vertical direction, and the amount by which the steel pipe 32 protrudes downward from the tip of the steel plate member 15 can be adjusted.

  Even when such a steel plate member 15 and steel pipe 32 are used, the steel plate underground partition wall 2 can be formed by press-fitting in the same manner as the steel plate member 11 shown in FIGS. 3 and 4. Then, the steel plate member 15 can be easily press-fitted by supplying water into the steel pipe 32 from above and feeding water into the ground near the lower end of the steel plate member 15. Further, in this embodiment, as shown in FIGS. 9 (a) and 9 (b), the amount that the tip of the steel pipe 32 protrudes from the tip of the steel plate member 15 is changed, and as shown by the arrows in the figure, it is appropriate for the ground It is possible to appropriately reduce the press-fitting resistance by supplying water to the position. Furthermore, the amount of protrusion of the steel pipe 32 can be changed while the single steel plate member 15 is press-fitted to supply water into a wide range of ground, and the press-fit resistance of the ground to the steel plate member 15 can be reduced. The steel pipe 32 can be extracted upward after the press-fitting of the steel plate member 15 is completed.

  In the method of press-fitting a steel plate member having a tube holding portion together with the steel pipe, a steel plate member as shown in FIG. 8B can also be used. This steel plate member 16 is provided with a joining processed portion 16a having a circular cross section at both side edge portions. The above-mentioned joining processing portion 16a having a circular cross section has a radius of curvature changed in the middle of the circular arc, and the joining processing portion 16a of the adjacent steel plate member 16 and the arc-shaped portion overlap each other. Can be joined together.

  When the steel plate member 16 is press-fitted, the position of one joining processed portion 16a-1 is aligned with the joining processed portion 16a-0 of the steel plate member 16-0 that has been previously press-fitted, and both are joined. Press fit. And the steel pipe 32 is inserted in the inner side where the cross section of the other processing part 16a-2 for joining became circular arc shape, and water is supplied to the lower end vicinity of the steel plate member 16 from upper direction. After the press-fitting of the steel plate member 16 is completed, the steel pipe 32 is extracted upward from the bonding processing portion 16a-2, and this bonding processing portion 16a-2 is engaged with the bonding processing portion of the steel plate member to be pressed next. Then, the steel plate members are sequentially press-fitted.

  Even when such a steel plate member 16 is used, water is supplied to the ground in the vicinity of the tip of the steel plate member 16 and the tip of the steel pipe 32 is a steel plate as in the case of using the steel plate member 15 shown in FIG. The amount of protrusion of the member 16 is adjusted to appropriately reduce the resistance when the steel plate member 16 is press-fitted, and the steel plate member 16 can be press-fitted into the ground without buckling.

Next, another embodiment of the present invention, which is another method for press-fitting a steel plate member having low bending rigidity without causing buckling, will be described.
In this method, a steel plate member and a stiffening member having rigidity higher than that of the steel plate member are overlapped and press-fitted, and a steel plate member 17 and a steel plate thicker than the steel plate member 17 are bent as shown in FIGS. The processed stiffening member 33 is overlapped and press-fitted. The stiffening member 33 includes a stiffening portion 33a that is bent so as to protrude toward one surface at the center of the horizontal cross section, and both side portions 33b of the stiffening portion 33a are connected to the steel plate member 17. It is the opposite. The front ends of the steel plate member 17 and the stiffening member 33 have a shape in which the central portion in the width direction is convex downward and both side portions are receded upward. And the front-end | tip part of the steel plate member 17 is wound along the front-end | tip surface of the stiffening member 33, and is provided with the folding | returning part 17a turned up. Thereby, the force which press-fits the stiffening member 33 in the ground is transmitted to the steel plate member 17 through the folded portion 17a. Therefore, when the steel plate member 17 and the stiffening member 33 are overlapped and press-fitted, the compressive force of the steel plate member 17 due to the pressing force acting on the upper end is reduced, and the force to press the stiffening member 33 is reduced. 17 can be press-fitted in a superposed state while being transmitted. Thus, by reducing the compressive force of the steel plate member 17, it is possible to prevent the buckling of the steel plate member 17 and press-fit the steel plate member 17. After the steel plate member 17 is press-fitted to a predetermined depth, when the stiffening member 33 is pulled upward, the engagement between the front end portion of the steel plate member 17 and the stiffening member 33 is released, and only the stiffening member 33 is pulled out. .

  In the method of press-fitting a steel plate member together with the stiffening member 33 as described above, instead of the steel plate member 17, for example, a steel plate member 11 having a tubular portion as shown in FIGS. Water can also be supplied to the ground near the tip of the. When the steel plate member 11 having such a tubular portion is press-fitted together with the stiffening member 33, the steel plate member 11 and the stiffening member 33 can be overlapped as shown in FIG.

In addition to the embodiment described above, the present invention can include a method of bringing the processed portions for joining steel plate members into close contact with each other at the joined portions between adjacent steel plate members. This method is as follows.
As shown in FIG. 13A, the steel plate member 18 used in this embodiment has a stiffening portion 18a, that is, a tubular portion, to which a steel pipe is attached between both side edges in the horizontal cross section of the steel plate member 18. In addition, a second stiffening portion 18b that is bent into a cross-sectional shape that is long in a direction perpendicular to a line connecting both side edges is provided. Then, as shown in FIG. 13B, both sides of the second stiffening portion 18b can be elastically deformed in directions away from each other, and the concave portion of the second stiffening portion 18b is formed. Enlarged by elastic deformation. The shape holding member 34 can be inserted and sandwiched in the enlarged recess. That is, the shape maintaining member 34 can be inserted into the concave portion of the second stiffening portion 18a, and the state in which the steel plate member 18 is elastically deformed can be maintained. The shape retaining member 34 has a compressive strength that can maintain the elastic deformation of the steel plate member 18. When the water is absorbed, the compressive strength is reduced, and the steel plate member 18 that has undergone elastic deformation is restored to its original shape. Those that are unable to resist the force of returning to shape are used. For example, mudstone that collapses by absorbing water, dried and solidified clay, starchy solidified material, and the like can be used.

  The steel plate member 18 is press-fitted into the ground with the shape-retaining member 34 sandwiched between the second stiffening portions 18b and joined to adjacent steel plate members 18 'and 18 "as shown in FIG. 13 (c). In this state, a steel plate underground partition is formed.When the steel plate member 18 is press-fitted, the bonding processing portion 18c is joined to the bonding processing portions 18'c, 18 "c of the adjacent steel plate members 18 ', 18". It is difficult to sequentially press-fit in close contact with each other, and as shown in FIG. 13C, the engagement ends 18d, 18'd, 18 "d of the adjacent steel plate members 18, 18 ', 18" are separated from each other. However, after the press-fitting of the steel plate members 18, 18 ′, 18 ″, when the shape retaining member 34 absorbs water and loses the compressive strength with the passage of time, it is elastic as shown in FIG. By the shape holding member 34 of the deformed steel plate member 18 Bundle is released, it deforms in a direction in which both sides of the second stiffening part 18b approach each other. That is, it deform | transforms so that the width | variety of the steel plate member 18 may shrink. As a result, the processing portions 18c, 18'c, and 18 "c for joining adjacent steel plate members are displaced away from each other, and the engagement ends 18d, 18'd, and 18" d are brought into close contact with each other. Thereby, the water tightness in the joint part of the steel plate member 18 is improved, and the flow of water through the partition walls can be suppressed even when the pore water pressure is increased by vibration during an earthquake.

  Moreover, even if it is the steel plate member 19 which is not provided with the tubular part for supplying water near the front-end | tip of a steel plate member, the shape holding member 34 can be inserted | pinched like the 2nd stiffening part 18b shown in FIG. The steel plate member provided with the stiffening portion 19a is overlapped with the stiffening member 33 as shown in FIG. 14 and press-fitted into the ground as in the embodiment shown in FIG. 13, and the press-fitting of the steel plate member 19 is completed. The joint can be brought into close contact later.

  The present invention is not limited to the embodiments described above, and can be implemented in other forms within the scope of the present invention.

1: building, 1a: foundation of building, 2: steel plate underground partition, 2a: corner of steel plate underground partition, 3: steel shielding plate, 4: steel pile, 5: liquefied layer, 6: liquefaction Easy layer, 7: Backfill soil,
11: Steel plate member, 11a: Main body portion of the steel plate member, 11b: Steel pipe attached to the steel plate member, 11c: Processing portion for joining, 11d: Stiffening portion, 11e: Engagement end, 11f: Lower end surface of the steel pipe, 11g : Steel pipe upper end, 12: Corner steel plate member, 12a: Joining processed part, 13: Steel plate member, 13a, 13b: Joining processed part, 13c: Stiffening part, 14: Steel plate member, 14a: Loop 14a: position where the looped stiffening portion is closed, 15: steel plate member, 15a: stiffening portion, 15b: opening portion on the concave side of the stiffening portion, 15c: Arc-shaped part of stiffening part, 16: Steel plate member, 16a: Processing part for joining, 17: Steel plate member, 17a: Folding part, 18: Steel plate member, 18a: Stiffening part, 18b: Second stiffening Part, 18c: processing part for joining, 18d: engagement end , 19: Steel plate member, 19a: Stiffening part,
21: bolt, 22: nut,
31: Construction machine, 32: Steel pipe, 33: Stiffening member, 33a: Stiffening part, 33b: Both sides of stiffening part, 34: Shape retaining member

Claims (4)

A plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are sequentially pressed into the ground so that adjacent steel plate members and side edges are connected to each other,
The steel plate member has a portion whose horizontal cross-sectional shape is closed, and this closed portion is a tubular portion that is continuous in the vertical direction, supplying water from the upper portion of the tubular portion, and water from the lower end. A method of forming a steel plate underground partition wall, wherein the steel plate member is press-fitted into the ground while discharging. A plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are sequentially pressed into the ground so that adjacent steel plate members and side edges are connected to each other,
The steel plate member has a tube holding portion whose cross-sectional shape is bent so that it can abut on the outer peripheral surface of the tube member having an axis in the vertical direction and restrain the relative displacement in the horizontal direction of the tube member,
A steel plate underground partition wall characterized in that the pipe member is held by the pipe holding portion of the steel plate member, and the steel plate member is press-fitted into the ground while water is supplied from the upper part of the pipe member and water is discharged from the lower end. Forming method. A plurality of steel plate members having a predetermined size in the horizontal direction and a predetermined length in the vertical direction are sequentially pressed into the ground so that adjacent steel plate members and side edges are connected to each other,
The steel plate member has a folded portion that is bent so that the tip portion is folded upward,
The steel plate member is overlapped with a plate-shaped stiffening member made of steel, and the folded portion is wound around and fitted to the tip of the stiffening member,
Press-fit into the ground with the stiffening member and the steel plate member overlapped,
After press-fitting to a predetermined depth, the stiffening member is pulled out. The steel plate member has a portion in which a horizontal cross-sectional shape is bent into a concave shape,
Elastic deformation is generated so that the concave portion is expanded on both sides, and a shape holding member is fitted into the concave portion, and the state in which the elastic deformation is generated is maintained and the steel plate member is press-fitted into the ground. ,
The shape-retaining member has a compressive strength that maintains the shape of the elastically deformed concave portion before the steel plate member is press-fitted into the ground, and is only compressed to maintain elastic deformation of the steel plate member by water absorption. The method for forming a steel plate underground partition wall according to any one of claims 1 to 3, wherein a material that loses strength is used.

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