JP5835010B2 - Construction method of Z-shaped steel sheet pile - Google Patents

Description

The present invention relates to a Z-shaped steel sheet pile having a web portion and flange portions formed at both ends of the web portion, and more particularly to a construction method for the Z-shaped steel sheet pile.

  A so-called Z-shaped steel sheet pile having flange portions at both ends and a web portion at an intermediate portion is known (see Patent Document 1).

JP 2002-294691 A

Since the Z-shaped steel sheet pile has an asymmetric cross-sectional shape, rotation occurs during the placement when placing each sheet. For this reason, the straightness of the steel sheet pile is not maintained, and the resistance of the fitting joint that is fitted increases, so that there are many cases where the construction becomes difficult, and there is a problem that the workability is poor.
As a technique for improving this, two Z-shaped steel sheet piles are connected in advance so as to form a so-called hat shape whose cross-sectional shape is a target (see FIG. 11 of Patent Document 1), and the fitted joint portion is caulked or There is a method of connecting and fixing by welding or the like.
However, when two Z-shaped steel sheet piles are connected to form a symmetric cross-sectional shape, the steel sheet pile cross-section becomes large and the penetration resistance at the time of driving increases, so that a special driving machine is required.
In addition, in order to transmit the propulsion force of the driving machine to the steel sheet pile normally, the chucking method of the steel sheet pile also requires two-point chucking, in which the web part of each Z-shaped steel sheet pile is individually required. A special one is required.

This invention is made | formed in order to solve this subject, and obtains the construction method of the Z-shaped steel sheet pile which can construct a Z-shaped steel sheet pile, suppressing rotation etc., without requiring a special driving machine. It is an object.

The inventor examined the cause of the rotation (twisting) of the conventional Z-shaped steel sheet pile during placement. FIGS. 16 and 17 are explanatory views for explaining the result of the examination. FIGS. 16 and 17 illustrate a general Z-shaped steel sheet pile 21 having flange portions 25a and 25b at both ends of the web portion 23. FIG. .
At the time of placing, the surrounding ground (regions A and B surrounded by the broken line circles in FIG. 16 are locally subjected to large shear in the corners 29a and 29b of the Z-shaped steel sheet pile 21. The state of particle arrangement changes and volume expansion occurs (soil dilatency phenomenon) .When volume expansion occurs in the surrounding ground, an uneven earth pressure is generated in which the earth pressure at the site increases locally, and the Z shape The steel sheet pile 21 receives a force in the direction of the arrow shown in FIG. 17 and is deformed and rotated (twisted).
From the above examination, the inventor suppresses deformation and rotation (twist) generated in the Z-shaped steel sheet pile by allowing the Z-shaped steel sheet pile 21 to receive an earth pressure that balances the uneven earth pressure from the surrounding ground. Therefore, it was considered that the straightness of the Z-shaped steel sheet piles can be maintained at the time of placing.
The present invention has been made based on such findings, and specifically comprises the following configuration.

(1) The Z-shaped steel sheet pile construction method according to the present invention includes a web portion, a flange portion formed at both ends of the web portion, and a joint portion formed at the end of the flange portion. A steel sheet pile construction method,
To both sides of the web portion centered on the outer surface side and / or the web portion outer surface of the flange portion in said Z-shaped steel sheet pile, it has a projecting edge portion of the above height 50mm that projects outward, the Z-shaped The Z-shaped steel sheet pile is driven in a state where an auxiliary member made of a member different from the steel sheet pile is attached.

(2) Moreover, in the thing as described in said (1), the said auxiliary member has the length over the full length of a Z-shaped steel sheet pile, It is characterized by the above-mentioned.

(3) Further, in the above (1) or (2), the auxiliary member has a lateral side portion extending in a direction intersecting with the protruding side portion on the proximal end side of the protruding side portion in the cross-sectional shape. It is characterized by this.

(4) Moreover, in the thing in any one of said (1) thru | or (3), as for the said auxiliary member, cross-sectional shape is either L shape, I shape, T shape, C shape, or H shape It is characterized by being.

(5) Moreover, in the thing as described in said (3) or (4), the said auxiliary member arrange | positions so that a side part may straddle a web center while arrange | positioning a projecting side part on both sides on both sides of a web center The horizontal side portion is chucked by a chuck of a driving machine to perform the driving.

(6) Further, in the device according to any one of the above (1) to (5), the auxiliary member is placed in a state of being temporarily fixed to the head of the Z-shaped steel sheet pile, and then temporarily fixed. The member is removed from the Z-shaped steel sheet pile, and only the auxiliary member is pulled up from the ground.

In the present invention, an auxiliary member having a protruding side portion protruding outward is attached to both sides sandwiching the web portion center on the outer surface side of the flange portion and / or the web portion outer surface side in the Z-shaped steel sheet pile. Since the Z-shaped steel sheet piles are driven in, even if Z-shaped steel sheet piles that are asymmetrical are driven one by one, the rotation and twisting during the driving are suppressed, and the Z-shaped steel sheet piles go straight. It becomes possible to maintain the sex.
By maintaining the straightness of the Z-shaped steel sheet pile, it becomes easy to form the steel sheet pile wall at a predetermined position, and the resistance of the fitting part fitting portion when placing the Z-shaped steel sheet pile is reduced. Construction speed and construction accuracy can be increased without using a simple construction machine.

It is explanatory drawing of the construction method of the Z-shaped steel sheet pile which concerns on one embodiment of this invention. It is explanatory drawing of the whole shape of the Z-shaped steel sheet pile shown in FIG. It is explanatory drawing explaining the effect | action of the construction method of the Z-shaped steel sheet pile shown in FIG. 1 (the 1). It is explanatory drawing explaining the effect | action of the construction method of the Z-shaped steel sheet pile shown in FIG. 1 (the 2). It is explanatory drawing of the other aspect of the construction method of the Z-shaped steel sheet pile which concerns on one embodiment of this invention. It is explanatory drawing of the whole shape of the Z-shaped steel sheet pile shown in FIG. It is explanatory drawing explaining the effect | action of the construction method of the Z-shaped steel sheet pile shown in FIG. 5 (the 1). It is explanatory drawing explaining the effect | action of the construction method of the Z-shaped steel sheet pile shown in FIG. 5 (the 2). It is explanatory drawing of the guide jig used for the construction method of the Z-shaped steel sheet pile which concerns on one embodiment of this invention. It is explanatory drawing of the other aspect of the attachment method of the auxiliary member used for the construction method of the Z-shaped steel sheet pile which concerns on one embodiment of this invention. It is explanatory drawing of the other aspect of the auxiliary member used for the construction method of the Z-shaped steel sheet pile which concerns on one embodiment of this invention. It is an explanatory view illustrating a Z-shaped steel sheet pile (Model) used in the experiments shown in the embodiment of the present invention. It is explanatory drawing of the construction method of the Z-shaped steel sheet pile of Example 1 of this invention. It is explanatory drawing of the construction method of the Z-shaped steel sheet pile of Example 2 of this invention. It is explanatory drawing of the construction method of the Z-shaped steel sheet pile of Example 3 of this invention. It is explanatory drawing explaining the mechanism in which rotation (twisting) arises at the time of casting at the time of Z-shaped steel sheet pile placing (the 1). It is explanatory drawing explaining the mechanism in which rotation (twisting) arises at the time of casting at the time of Z-shaped steel sheet pile placing (the 2).

The Z-shaped steel sheet pile 1 according to the present embodiment has a web portion 3 and flange portions 5a and 5b at both ends of the web portion 3, and joint portions 7a and 7b are formed at both ends of the flange portions 5a and 5b. Yes.
In the following description, as shown in FIG. 1, a line passing through the center of the web portion 3 and parallel to the flange portions 5a and 5b is defined as a boundary line (a chain line in the figure). The inside of the corner portion 9a formed by the portion 5a and the web portion 3 is the inner surface side, and the outer side is the outer surface side. Similarly, on the lower side of the boundary line, the inner side of the corner portion 9b is the inner surface side, and the outer side is the outer surface side.
In the construction method of the Z-shaped steel sheet pile 1 according to the present embodiment, auxiliary members 11a and 11b having protruding side portions 10a and 10b protruding outward are attached to the outer surface side of the flange portions 5a and 5b. The Z-shaped steel sheet pile 1 is driven in a state.

  The auxiliary members 11a and 11b of the present embodiment are members having an L-shaped cross section, and the auxiliary members 11a and 11b are attached so that the side portions 12a and 12b are along the vicinity of the joint portion on the outer surface side of the flange portions 5a and 5b. It is touched. The contact means that the auxiliary members 11a and 11b are fixed to the Z-shaped steel sheet pile 1 and fixed or temporarily fixed. The fixing method may be fastening with bolts and nuts, welding or fixing with an adhesive. Moreover, as a method of temporary fixing, it may be a method of temporary welding or adhesion that can be fastened and detached with bolts and nuts, or chucking with a steel sheet pile when a steel sheet pile construction machine is gripped.

In addition, when auxiliary member 11a, 11b is fixed, auxiliary member 11a, 11b will be buried without removing the Z-shaped steel sheet pile 1 after construction . On the other hand, when the auxiliary members 11a and 11b are temporarily fixed, after the Z-shaped steel sheet pile 1 is placed, the temporary fixing may be removed and only the auxiliary members 11a and 11b may be lifted to the ground. When the auxiliary members 11a and 11b are temporarily fixed, the auxiliary members 11a and 11b can be removed from the Z-shaped steel sheet pile 1 after the placement is completed. Moreover, since the auxiliary members 11a and 11b can be repeatedly used, the economy is excellent.
In addition, although the timing which removes auxiliary member 11a, 11b from the Z-shaped steel sheet pile 1 is normally performed after completion of the placement of the Z-shaped steel sheet pile 1, it is suitable for the removal and there is a problem in the subsequent placement. If not, it may be before the placement is completed.

  As shown in FIG. 2, the auxiliary members 11a and 11b can be easily fixed temporarily at the head of the Z-shaped steel sheet pile 1 by using the same length as that of the Z-shaped steel sheet pile 1, as described above. An effect is obtained. But when fixing auxiliary member 11a, 11b, you may provide continuously in the predetermined range near only the lower end part of Z-shaped steel sheet pile 1, or the front-end | tip part of Z-shaped steel sheet pile 1. FIG. As a predetermined range, about 1/2 to 1/3 of the full length from the front-end | tip part of the Z-shaped steel sheet pile 1 is mentioned as an example. When the auxiliary members 11a and 11b are attached in a predetermined range, a plurality of auxiliary members 11a and 11b having a short length may be discretely attached to the Z-shaped steel sheet pile 1.

The effect | action of the Z-shaped steel sheet pile 1 comprised as mentioned above is demonstrated based on FIG. 3, FIG.
At the time of placing, as described above, the surrounding ground (regions A and B surrounded by the broken line circles in FIG. 3) locally has a large shear inside the corner portions 9a and 9b of the Z-shaped steel sheet pile 1. receive. On the other hand, since auxiliary members 11a and 11b are provided outside the corner portions 9a and 9b, the surrounding ground (regions C and D surrounded by broken lines in FIG. 3) also has a large shear force locally. receive.
Therefore, as shown in FIG. 4, uneven earth pressure is generated inside and outside the corner portions 9a and 9b, and these cancel out the uneven earth pressure, thereby preventing the occurrence of rotation (twisting) when placing the steel sheet pile. it can. Therefore, even when the Z-shaped steel sheet piles 1 having an asymmetric shape are driven one by one, the straightness of the steel sheet piles can be maintained.
Moreover, while maintaining the straightness of the Z-shaped steel sheet pile 1, it becomes easy to form the steel sheet pile wall constructed by the Z-shaped steel sheet pile 1 at a predetermined position, and the joint portion at the time of steel sheet pile driving The resistance of the fitting portion is reduced, and the construction speed and workability can be improved without using a special construction machine.

  In addition, since the auxiliary members 11a and 11b are for generating an unloading pressure that balances the unloading pressure generated inside the corner portions 9a and 9b, the height H of the protruding side portions 10a and 10b is: What is necessary is just to make it change according to the uneven earth pressure which generate | occur | produces inside corner part 9a, 9b. However, in order to generate a large local shear in the surrounding ground of the auxiliary members 11a and 11b and to exert a sufficient rotation (twist) suppression effect, the height H of the protruding side portions 10a and 10b should be 50 mm or more. desirable.

In the above example, the auxiliary members 11a and 11b are attached to the outer surface side of the flange portion. However, the position where the auxiliary members 11a and 11b are attached may be the web portion 3 of the Z-shaped steel sheet pile 1. When contacting the web part 3, as shown in FIGS. 5 and 6, the web part 3 is attached to the outer surface side of the web part with the center of the web part (dashed line) interposed therebetween. By attaching the auxiliary members 11a and 11b over the entire length of the Z-shaped steel sheet pile 1 as shown in FIG. 6, the same effects as those of FIG. 2 described above can be obtained.
Since there is a case where a cut beam or an upset is joined to the outer surface side of the flange portion of the Z-shaped steel sheet pile 1, if the auxiliary members 11a and 11b are fixed, the attachment positions of the auxiliary members 11a and 11b are web portions. 3 is preferable. In this case, it is more preferable that the protruding side portions 10a and 10b of the auxiliary members 11a and 11b do not protrude outwardly from the extension line of the flange portion outer surface.

  In addition, when the auxiliary members 11a and 11b are brought into contact with the web portion 3, if the protruding side portions 10a and 10b of the auxiliary members 11a and 11b are too close to the center of the web portion, the earth pressure generated inside the corner portions 9a and 9b. Therefore, it is necessary to move away from the center of the web portion by a predetermined distance toward the flange portions 5a and 5b. If the distance from the center of the web part to the outer surface of the flange part is Wo, the predetermined distance is preferably 0.5 Wo or more.

  Even when the auxiliary members 11a and 11b are brought into contact with the web portion 3 of the Z-shaped steel sheet pile 1, as shown in FIGS. 7 and 8, the steel sheet pile has been described with reference to FIGS. By the same operation, it is possible to maintain the straightness of the steel sheet pile even when the Z-shaped steel sheet piles 1 are driven one by one.

  In addition, when attaching the auxiliary members 11a and 11b to the Z-shaped steel sheet pile 1, as shown in FIG. A guide jig 13 may be attached. The guide jig 13 may be only the steel sheet pile tip, or may be attached to the steel sheet pile tip and the steel sheet pile head, or an intermediate position as necessary.

Further, as shown in FIG. 10, when the auxiliary members 11a and 11b having an L-shaped cross section are attached to the web portion 3, the protruding side portions 10a and 10b are arranged on both sides of the web center 3a and the lateral side in the L shape. By arranging the portions 12a and 12b so as to straddle the web center 3a , the auxiliary members 11a and 11b can be connected to the web portion 3 if the vicinity of the web center 3a is chucked by the chuck of the placing machine when the Z-shaped steel sheet pile 1 is placed. of the chuck and it is possible to chuck at the same time, excellent workability.

In the above description, the shape of the auxiliary members 11a and 11b has been described by taking the L-shaped cross section as an example, but in the case of the L-shaped cross section, either the equilateral L shape or the unequal side L shape may be used. Alternatively, in addition to the L-shaped section, for example, a T-shaped section as shown in FIG. 11 may be used, or the sectional shape may be an I-shaped, H-shaped, or C-shaped (channel material).
However, the auxiliary members 11a and 11b preferably have lateral side portions 12a and 12b extending in a crossing direction with the protruding side portions 10a and 10b on the base end side of the protruding side portions 10a and 10b in the cross-sectional shape. If it is a simple shape, the horizontal sides 12a and 12b can be easily fixed and temporarily fixed along the flanges 5a and 5b of the Z-shaped steel sheet pile 1 and the web 3.

An embodiment of the present invention will be described with reference to FIGS.
A 9 mm thick plate is formed into a Z shape by bending (sheet pile height 400 mm, sheet pile width 450 mm), and the joint members 14 a and 14 b (model) are welded to the ends to form a Z-shaped steel sheet pile (model) 15. Formed (see FIG. 12). The steel sheet pile length was 12 m, and the construction completion length (placement length) was 11 m.
Example 1 in which auxiliary members 11a and 11b arranged on the outer surface side of the flange portion of the Z-shaped steel sheet pile (model) 15 are fixed and attached at the head of the Z-shaped steel sheet pile (model) 15 (see FIG. 13). And Example 2 (refer FIG. 14) which fixed and joined auxiliary member 11a, 11b arrange | positioned in the corner | angular part 9a, 9b vicinity in the web part 3 with the head of Z-shaped steel sheet pile (model) 15, For Example 3 (see FIG. 15) in which the auxiliary members 11a and 11b arranged near the center of the web part 3 are chucked simultaneously with the web part 3 by the chuck of the placing machine, the Z-shaped steel sheet pile (model) 15 is struck alone. Was implemented.
For comparison, the same placement was carried out as a comparative example with respect to the members not attached to the auxiliary members 11a and 11b shown in FIG.
The results are shown in Table 1.

The “punchable length of second sheet placement (with joint fitting)” in each case in Table 1 indicates the length that can actually be placed in each case.
In the comparative example in which the auxiliary members 11a and 11b were not attached, the “punchable length of the second piece placement (with fitting fitting)” was 3 m. This is because, as described above, when the first sheet is placed alone, the steel sheet pile is rotated (twisted) in the ground due to local earth pressure (uneven earth pressure), so the second sheet is placed (with joint fitting). This is because the resistance of the joint fitting portion is increased.
On the other hand, in all of Examples 1 to 3 in which the auxiliary members 11a and 11b are attached, the “installable length of the second sheet placement (with joint fitting)” is the construction completion length (placement length). It reached 11m. This is because the effect of the auxiliary members 11a and 11b restrains the rotation (twisting) of the steel sheet pile when the first piece is placed alone, so that the joint fitting portion is provided when the second piece is placed (with joint fitting). This is because the resistance did not increase.
From the above experiments, the effects of the auxiliary members 11a and 11b were confirmed.

A, B, C, D area 1 Z-shaped steel sheet pile 3 Web part
3a Web center 5a, 5b Flange part 7a, 7b Joint part 9a, 9b Corner part 10a, 10b Protruding side part 11a, 11b Auxiliary member 12a, 12b Lateral side part 13 Guide jig 14a, 14b Joint member 15 Z-shaped steel sheet pile ( model)
21 Z-shaped steel sheet pile (conventional example)
23 Web part 25a, 25b Flange part 29a, 29b Corner part

Claims (6)

It is a construction method of a Z-shaped steel sheet pile having a web part, a flange part formed at both ends of the web part, and a joint part formed at an end part of the flange part,
To both sides of the web portion centered on the outer surface side and / or the web portion outer surface of the flange portion in said Z-shaped steel sheet pile, has a projecting edge portion of the above height 50mm that projects outward, the Z-shaped A construction method of a Z-shaped steel sheet pile, wherein the Z-shaped steel sheet pile is driven in a state in which an auxiliary member made of a member different from the steel sheet pile is attached.   The construction method for a Z-shaped steel sheet pile according to claim 1, wherein the auxiliary member has a length extending over the entire length of the Z-shaped steel sheet pile.   The construction of the Z-shaped steel sheet pile according to claim 1, wherein the auxiliary member has a lateral side portion extending in a direction intersecting with the protruding side portion on the base end side of the protruding side portion in a cross-sectional shape. Method.   The Z shape according to any one of claims 1 to 3, wherein the auxiliary member has a cross-sectional shape of any one of an L shape, an I shape, a T shape, a C shape, and an H shape. Steel sheet pile construction method. The auxiliary member is provided with projecting side portions on both sides sandwiching the web center and with the lateral side portions straddling the web center, and the lateral side portions are chucked by a chuck of a placement machine for placement. The construction method of the Z-shaped steel sheet pile of Claim 3 or 4 characterized by the above-mentioned. The auxiliary member is placed in a state of being temporarily fixed to the head of the Z-shaped steel sheet pile, and then the temporarily fixed auxiliary member is removed from the Z-shaped steel sheet pile, and only the auxiliary member is pulled up from the ground. The construction method of the Z-shaped steel sheet pile as described in any one of Claim 1 thru | or 5.