JP2006257806A - Earth retaining steel material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earth retaining steel material capable of surely checking risk of collapse and deluge of the ground, even without improving the ground, without requiring to improve the ground, due to being extremely high in water cut-off performance. <P>SOLUTION: This earth retaining steel material is formed of a U-shaped part 1d composed of a flange part 1a extending in the connecting direction of the earth retaining steel material 1 and webs 1b and 1c respectively arranged on both ends of the flange part 1a, flat parts 1e and 1f respectively arranged on the tip of the web 1b and the web 1c and extending in the connecting direction of the earth retaining steel material 1, and joint parts 1g and 1h respectively asymmetrically arranged on the tip of the flat parts 1e and 1f. The sum total (L<SB>1</SB>+L<SB>3</SB>) of the width length of the flat part 1e and the flat part 1f is formed substantially equal to the width length L<SB>2</SB>of the flange La, or the width length L<SB>2</SB>of the flange 1a is formed longer than the sum total (L<SB>1</SB>+L<SB>3</SB>) of the flat part 1e and the flat part 1f. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to earth retaining steel materials used for underground continuous walls constructed in the ground in preparation for large earth pressure and water pressure, for example, temporary earth retaining in civil engineering construction work, revetment of harbors and rivers, shafts in shield construction method It has been developed to be suitable for applications such as earth retaining walls and barrier walls required in waste disposal sites.

  Steel sheet piles are often used as earth retaining walls when constructing underground structures, provisional deadlines when constructing harbors and water facilities, and as shaft walls when constructing shafts for shield excavation. The reason is that a high-rigidity wall can be constructed within a relatively short construction period by a high-quality material called steel.

  However, when constructing earth retaining walls and temporary cut-offs for large earth pressure and water pressure using steel sheet piles, the joints between steel sheet piles cannot avoid the occurrence of gaps depending on the mating state, so water impermeability can be avoided. It has a big influence and is a big problem.

  Therefore, in general, steel sheet piles are placed in a row while fitting and connecting the joints provided on each steel sheet pile, especially in the case of a continuous wall that surrounds industrial waste that may contain harmful substances Applied a water-swellable water-stopping material inside the joint, and the water-stopping material expanded to cause clogging inside the joint, thereby exhibiting water-stopping properties. In addition, the steel sheet piles have been doubled.

Furthermore, in the shield method, in order to construct a shaft used as a shield start / arrival base with steel sheet piles, after placing the steel sheet pile and constructing the retaining wall of the shaft, the chemical solution is applied to the ground outside the retaining wall. Improving the ground of the shield construction part (shield excavation part) by injection or freezing method, etc., excavating the retaining wall, placing concrete at the wellhead in order, and then cutting and removing the steel sheet pile at the shield construction part Or pulling out the shield construction part so that the shield machine can start or reach, or as another method, after placing a steel sheet pile and building a shaft, further on the shield construction side (shield excavation side) A steel sheet pile shaft was constructed, a shield machine was installed in the shaft, backfilled, and a steel sheet pile at the shield construction part of the shaft where the shield machine was embedded was drawn. Unplug, the shield machine had to be able to start.
JP 2003-214086 A Japanese Patent No. 2640920 Japanese Patent No. 2699152

  However, swellable water-stopping materials need to be applied to the steel sheet pile joints in advance before construction, which is very troublesome and may be partially peeled off due to friction during construction. There was a possibility that water performance could not be fully exhibited.

  On the other hand, in the method of placing steel sheet piles twice, even if the steel sheet pile is driven later along the side of the steel sheet pile previously placed on the shape of the steel sheet pile, there is a large gap between the steel sheet piles. It was unavoidable that it was possible to improve the ground for this part. Moreover, the distance of the joint part between steel sheet piles cannot be earned, therefore, sufficient water stoppage was not obtained for using a large amount of steel sheet piles.

  In particular, when earth retaining work for shield excavation of steel sheet pile vertical shafts, there is a risk that the ground may collapse or flood when the steel sheet pile at the shield construction part is pulled out or cut, so this area will be improved. There is a problem that the construction process becomes complicated because it is necessary to construct the steel sheet pile twice.

  Moreover, even if the ground improvement was performed, when the steel sheet pile was pulled out from the shield construction part, the sealed state between the ground improvement part and the steel sheet pile could be cut off and the water could flow out.

  Patent Document 1 describes a method of joining two steel sheet piles like one steel sheet pile in order to solve this problem, but the work of joining and cutting the steel sheet piles is complicated, There is a risk that the construction method may be limited, or water may flow out at the time of attaching or detaching the joining part or joining part.

  Patent Documents 2 and 3 also describe a method of reducing the ground improvement range by providing a narrow space, but the ground improvement cannot be eliminated, and there is still room for improvement in order to shorten the construction period and reduce the construction cost. was there.

  The present invention has been made in view of such a situation, and has a very high water stoppage performance, requires no ground improvement, and can reliably prevent the collapse of the ground and the flooding without ground improvement. An object of the present invention is to provide a retaining steel material that can construct a continuous underground wall.

  The earth retaining steel material according to claim 1 is provided at each of a U-shaped portion composed of a flange extending in a connecting direction of the earth retaining steel material and webs provided at both ends of the flange and at the tip of the web, It has a flat part extending in the connecting direction and a joint part provided asymmetrically at the tip of the two flat parts, the earth retaining steel materials are shifted by a half pitch in the connecting direction so that the cross-sectional shape is reversed By being reversed, the flange and the flat part are formed so as to overlap each other.

  The earth retaining steel material according to claim 2 is the earth retaining steel material according to claim 1, wherein the sum of the width lengths of the flat portions is equal to the width length of the flange, or the width length of the flange is the width of the flat portion. The inner radius formed by the flange and the web is larger than the sum of the lengths, and the outer radius formed by the web and the flat portion is substantially equal to or larger than the outer radius.

  In particular, the present invention has a structure in which the size of each part of the retaining steel material and the inner radius and the outer radius formed by each part are formed in the above-described relationship, so that when retaining a plurality of retaining steel materials in a double stack, The steel materials can be placed as close as possible.

  In this case, as the gap in close contact between the retaining steel materials that are double stacked, in the case of placing in a state where the fusing protection sheet is sandwiched, it is infinitely close (0.0 mm). However, if the earth and sand (natural ground) is used as a protective layer without using the fusing protection sheet, the fusing to the back-side earth retaining steel will be possible. The thickness of the crater can be prevented from penetrating, and the safety of the earth and sand (ground mountain) falling off when the back side retaining steel material is pulled out (melting of the excavating side retaining steel material is cut out by about 30 cm square from workability) Considering a gap of 5 cm or less is desirable.

  The earth retaining steel material according to claim 3 is the earth retaining steel material according to claim 1 or 2, and guides a joint portion of the earth retaining steel material that is installed on the upper surface of the flange of the earth retaining steel material so as to overlap the earth retaining steel material. A guide portion is provided.

  The earth retaining steel material according to claim 4 is the earth retaining steel material according to claim 1 or 2, wherein the guide portion is provided continuously in an end portion in the flange axial direction or in the flange axial direction. It is.

  The invention according to claim 3 and 4 is that the retaining steel material to be cast later is provided when the retaining steel material is provided with a guide portion on the flange of the retaining steel material, and when the retaining steel material is placed in close double contact. The guide part of the earth retaining steel material that was previously placed was guided and placed, so that the earth retaining steel material that was placed later was brought as close as possible to the earth retaining steel material that was previously placed. It can be placed in a state.

  In this case, in particular, as the retaining steel material to be cast at the beginning and the end, the end of the wall body of the retaining steel material is used by using a guide portion provided continuously in the axial direction of the retaining steel material. Since it can seal, it becomes possible to improve water stop performance to each stage.

  In this case, the guide portion can be formed very simply by attaching a separately formed guide member to the flange of the retaining steel material by bolting or welding.

  The earth retaining steel material according to claim 5 is the earth retaining steel material according to claim 1 or 2, wherein the earth retaining steel materials are closely applied to the flange or the flat part of the earth retaining steel material or to both sides thereof. The guide portion for guiding the fastening steel material is an alternative to the guide portion described in claim 3 or 4, and a long member made of a reinforcing bar, a steel strip, or the like is attached to the side portion of the flange and the flat portion by spot welding over the entire length thereof. It can be easily formed by mounting.

  In order to drive the earth retaining steel material into the ground, first, the earth retaining steel materials having guide portions on the side portions of the flange and the flat portion are placed in a row by aligning the cross-sectional shape in the same direction and connecting them together. Install eyes.

  Next, the steel retaining material without the guide part is reversed so that the cross-sectional shape of the retaining steel material in the first row is opposite to that of the first row, and is shifted by a half pitch, and is superimposed on the side portion of the retaining steel material in the first row. Are connected to each other, and the flat part is inserted between the flange and the guide part of the retaining steel material in the first row, and the flange is inserted between the flat part and the guide part. The second row is constructed by casting spot welding of the guide member while separating it from the flange and the flat part. By doing this, the back side retaining steel is pressed by earth pressure through reinforcing bars, steel strips, etc., and the second row of retaining steel is as close as possible to the side of the first row of retaining steel. You can type in.

  In particular, the present invention provides a U-shaped portion comprising a flange extending in the connecting direction of the steel retaining material and webs provided at both ends of the flange, and a tip of the web. A flat part extending in the connecting direction and a joint part provided asymmetrically at the tip of the flat part, and the sum of the widths of the flat parts is equal to the width of the flange or the width of the flange Is larger than the sum of the widths of the flat portions, and the inner radius formed by the flange and the web is substantially equal to or larger than the outer radius formed by the web and the flat portion. When placing the retaining steel material in the ground, it is possible to place it in a very close state. Only fell problems such as no longer, it is possible to achieve the safety of the construction.

  In addition, since it is not necessary to improve the ground by injecting chemicals into the gap between the retaining steel materials, the construction period can be shortened, the construction cost can be reduced, and the environment can be protected. Furthermore, one of the retaining steel materials overlapping each other is driven so as to cover the joint portion of the other retaining steel material with a flange, thereby reliably improving the water stoppage of each connecting portion between the retaining steel materials. Can do.

  In addition, the guide part is provided in the earth retaining steel material, so that when the earth retaining steel material is piled up twice, the earth retaining steel in which the joint part of the earth retaining steel material to be placed later is placed first. By engaging with the guide portion of the steel material and placing it with the guide as a guide, the earth retaining steel material to be placed later is placed as close as possible to the earth retaining steel material previously cast. be able to.

  FIG. 1 (a), (b) shows an example of the underground continuous wall of this invention, and the earth retaining steel material used in order to construct | assemble the said underground continuous wall, In the figure, several earth retaining steel materials 1 are shown. The earth retaining steel material 1 is installed in the ground so that the cross-sectional shapes thereof are aligned in the same direction and are connected to each other so that the concave and convex directions are opposite to each other.

  Each earth retaining steel material 1 includes a flange 1a extending in the connecting direction of the earth retaining steel material 1, a web 1b and a web 1c provided at both ends of the flange 1a, respectively, a U-shaped portion 1d, a flange 1b, and a distal end of the flange 1c. Are formed from a flat part 1e and a flat part 1f extending in the connecting direction of the retaining steel material 1, and a joint part 1g and a joint part 1h provided asymmetrically at the ends of the flat part 1e and the flat part 1f, respectively. Has been.

The sum (L ₁ + L ₃ ) of the widths of the flat part 1e and the flat part 1f is substantially equal to the width L ₂ of the flange 1a, or the width L _{2 of the} flange 1a is equal to the flat part 1e and the flat part 1f. It is formed longer than the sum of the widths (L ₁ + L ₃ ).

The inner radius R ₁ and R ₂ forming flange 1a and the web 1b and web 1c on both sides thereof, respectively formed to be almost equal to each other, and outer radius R ₃ formed by the web 1b and a flat portion 1e and the web 1c and flat outer radius R ₄ formed between section 1f is formed to be almost equal to each other, further inner radius R ₁ and an inner radius R ₂ is greater than the outer radius R ₃ and the outer radius R _4.

The width length L ₁ of the flat portion 1e here refers to the length of the immediately before the outer radius R ₃ from the center of the joint portion 1g, does not include the outer radius. The width length L ₃ of the flat portion 1f refers to length immediately before the outer radius R ₄ from the center of the joint portion 1h, does not include the outer radius R ₄ is.

  As shown in FIG. 1A, the earth retaining steel material 1 formed in this way has the same cross-sectional shape, and the joint portions 1g and 1h are fitted to each other and connected to each other, and the unevenness is It is installed twice by driving in the ground so that they are opposite to each other.

  Moreover, the one flange 1a of the earth retaining steel materials 1 and 1 that overlap each other is placed so as to cover the connecting portions of the joint portions 1g and 1h of the other earth retaining steel materials 1 and 1. That is, the earth retaining steel materials 1 are shifted by a half pitch in the connecting direction, inverted so that the cross-sectional shape is reversed, and the flanges 1a, the flat portions 1e, and the flat portions 1f are overlapped with each other. ing.

  Thus, when the earth retaining steel material 1 is double installed in the ground, the earth retaining steel material 1 is installed in the ground by the width, inner radius, and outer radius of each part of the earth retaining steel material 1 being formed in the above-described relationship. 1 and 1 can be driven into the ground in close contact with each other, and this causes problems such as biting of the natural ground and dropping of the natural ground caused by this when the earth retaining steel 1 is placed. In addition, there is no need to improve the ground for the gap formed between the retaining steel materials.

  In addition, since one flange 1a of the earth retaining steel materials 1 and 1 that overlap each other is placed so as to cover the connecting portions of the joint portions 1g and 1h of the other earth retaining steel materials 1 and 1, the earth retaining It is possible to reliably ensure the water stoppage of each connecting portion between the steel materials 1 and 1.

  2 (a) to (g) show an example of an underground continuous wall and a retaining steel material, and the retaining steel materials shown in FIGS. 2 (b) to (g) are all shown in FIGS. It is formed from the retaining steel material having the shape described in (b) and the guide portions 2, 3 or 4 respectively provided on the flange 1a of the retaining steel material.

  Each of the guide portions 2, 3 and 4 is formed to have a predetermined length (about 10 cm) in the axial direction of the flange 1a, that is, the axial direction of the retaining steel material 1, and is welded to the axial end portion of the flange 1a. It is attached by bolting.

  In particular, in the case of the retaining steel material shown in FIG. 2B, the guide portion 2 can be engaged with a joint 1h of the retaining steel material 1 that is placed on the side portion of the retaining steel material 1 afterwards. It is formed into a shape. The same guide portions 2 and 3 are used.

  Further, in the case of the retaining steel shown in FIG. 2 (c), the guide portion 3 has a shape that can be engaged with the joint portion 1h of the retaining steel 1 that is laid on the side of the retaining steel 1 afterwards. Is formed. In the case of the retaining steel material shown in FIG. 2 (d), the guide portion 4 has a shape that can be engaged with the joint portion 1g of the retaining steel material 1 that is placed on the side portion of the retaining steel material 1 afterwards. Is formed.

  Since each earth retaining steel material 1 has the guide portions 2, 3 or 4 as described above, when the earth retaining steel material 1 is placed in a straight line while being connected to each other, the joint of the earth retaining steel material to be placed later By engaging the guide portion of the retaining steel material that was previously cast and using this as a guide, the retaining steel material that was cast later can be used as the retaining steel material that was previously cast. It can be placed as close as possible.

  In this case, the guide portions 2, 3, and 4 are each formed by attaching a separately formed guide member by welding or bolting.

  Next, a method for constructing the underground continuous wall shown in FIG. 2A using the retaining steel shown in FIGS. 2B, 2C, and 2D will be described with reference to FIG.

  First, the retaining steel material 1A illustrated in FIG. In this case, as the earth retaining steel material 1A, one in which the guide portion 2 is continuously provided in the axial direction of the flange 1a, that is, the axial direction of the earth retaining steel material 1 is used.

  Next, the joint steel 1B and the guide part of the steel retaining steel 1 in which the guide part 3 is placed on the lower side and the guide part 3 and the joint part 1h are previously placed on the retaining steel material 1B illustrated in FIG. 2 is engaged with each other, and the guide portion 2 and the joint portion 1h are used as a guide to be piled on the side portion of the earth retaining steel material 1A previously placed.

  Next, the earth retaining steel 1C shown in FIG. 2D is connected to the joint part 1g and earth retaining member of the earth retaining steel 1B in which the guide part 4 is placed downward and the guide part 4 and the joint part 1g are placed first. The steel plate 1A is engaged with the joint portion 1h of the steel material 1A, and the joint portion 1h and the joint portion 1g are used as a guide to be piled on the side portion of the earth retaining steel material 1B previously placed.

  Similarly, the earth retaining steel material 1 shown in FIGS. 2 (c) and 2 (d) is driven in piles on the side portion of the earth retaining steel material 1 previously placed, and the guide portion 3 is used as the final earth retaining steel material. Or, 4 is driven in the retaining steel material provided continuously in the axial direction of the retaining steel material.

  Here, in particular, as the first and last earth retaining steel, the earth retaining steel material in which the guide portion is continuously provided in the axial direction of the earth retaining steel material is used. This is because the edge of the retaining steel material is brought into close contact with the entire length thereof.

  It should be noted that when the retaining steel material is piled on the side portion of the retaining steel material that was previously placed, the retaining steel material that was later placed on the guide portion provided on the retaining steel material that was previously placed is used. For example, as shown in FIG. 2 (e), the joint portion of the earth retaining steel material to be placed later is cut out by the length S of the guide portion because the joint portion hits and no further driving can be performed. Alternatively, as shown in FIGS. 2 (f) and 2 (g), the guide portion can be easily detached by the impact of the joint portion of the retaining steel material that has been cast later.

  2 (f) and 2 (g), a notch 1i having a predetermined length in the axial direction of the earth retaining steel material 1 is provided at the end of the flange 1a as shown in the figure. The guide portion 2 is attached so as to be detached in the opening direction of the notch portion 1i by a bolt / nut 6 and a plate 7 that pass through the plate.

  4 (a) and 4 (b) show an example of the underground continuous wall and the retaining steel material, and the retaining steel material in this case is the retaining steel material having the shape described in FIGS. 1 (a) and 1 (b). And the flange 1a of the earth retaining steel material and a plurality of guide portions 5 provided on the flat portions 1e and 1f.

  The guide part 5 is formed continuously in the axial direction of the flange 1a, the flat parts 1e and 1f, that is, the axial direction of the earth retaining steel material 1. For example, a strip steel or a reinforcing bar is provided on the side part of the flange 1a, flat parts 1e and 1f. It is formed by attaching. In this case, the steel strip or the reinforcing bar is attached so that it can be detached by impact at the time of placing by spot welding or the like.

  In such a configuration, in order to drive the earth retaining steel material into the ground, as shown in FIGS. 5 (a) and 5 (b), the earth retaining steel material is later placed on the side portion of the earth retaining steel material 1A. Overlaying the steel retaining steel material 1B, the flange 1a is first driven between the flange 1a of the steel retaining steel material 1A in which the flat portion 1f of the steel retaining steel material 1B to be placed later is first placed and the guide portion 5. Inserted between the flat part 1f of the retaining steel material 1A and the guide part 5, and the retaining steel material 1B to be placed later in this state, the guide part 5 and the flange 1a and the flat part by the impact at the time of placing Type in while separating from 1e.

  By driving the retaining steel material 1B to be placed later in this way, the retaining steel material 1B can be driven as close as possible to the side of the retaining steel material 1A.

  Further, as another example according to the ground conditions, the guide portions 5 of the flat portions 1e and 1f shown in FIGS. 4 (a) and 4 (b) are omitted, and adjacent ones placed in the first row are arranged. It can also be constructed with the guide part 5 of the retaining steel material as a guide.

  The present invention can be used for applications such as temporary earth retaining in civil engineering construction work, revetment of harbors and rivers, earth retaining walls of shafts in shield construction, and barrier walls required in waste disposal sites, etc. it can.

The underground continuous wall constructed | assembled as a retaining wall is shown, (a) is the partial top view, (b) is a top view of the retaining steel material used for the said underground continuous wall. The underground continuous wall constructed as a retaining wall is shown, (a) is a partial plan view thereof, (b), (c), (d), (e), (f) are the underground continuous walls. An end perspective view of the earth retaining steel used, (g) is an end view, and in particular (f) and (g) are designed so that the guide part can be easily removed. (a), (b), (c), (d) is a top view which shows the construction procedure of an underground continuous wall. The underground continuous wall constructed | assembled as a retaining wall is shown, (a) is the partial top view, (b) is the edge part perspective view of the retaining steel material used for the said underground continuous wall. The underground continuous wall constructed | assembled as a retaining wall is shown, (a) is the partial top view, (b) is the II line sectional drawing in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Earth retaining steel material 1a Flange 1b Web 1c Web 1d U-shaped part 1e Flat part 1f Flat part 1g Joint part 1h Joint part 1i Notch part 2 Guide part 3 Guide part 4 Guide part 5 Guide part 6 Bolt / nut 7 Plate

Claims (5)

  A U-shaped portion composed of a flange extending in the connecting direction of the retaining steel material and webs provided at both ends of the flange, and a flat portion provided at the tip of the web and extending in the connecting direction of the retaining steel material, and both the flats Each of the retaining steel members is shifted by a half pitch in the connecting direction and inverted so that the cross-sectional shape is reversed. An earth retaining steel material formed so as to be overlapped with a portion.   The sum of the widths of the flat parts and the width of the flanges are equal, or the width of the flanges is larger than the sum of the widths of the flat parts, and the inner radius formed by the flanges and the webs is the same as that of the webs The retaining steel material according to claim 1, wherein the retaining steel material is formed to be substantially equal to or larger than an outer radius formed by the flat portion.   3. The earth retaining steel material according to claim 1, wherein a guide portion is provided on the flange surface of the earth retaining steel material to guide a joint portion of the earth retaining steel material that is installed to overlap the earth retaining steel material. .   4. The retaining steel material according to claim 3, wherein the guide portion is provided continuously in an end portion in the flange axial direction or in the flange axial direction.   The guide part which guides the earth retaining steel material piled up on the said earth retaining steel material is provided in the flange and the flat part of the earth retaining steel material so as to be detachable. Earth retaining steel.

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