WO2020045114A1

WO2020045114A1 - Hat-shaped steel sheet pile and production method for steel sheet pile wall

Info

Publication number: WO2020045114A1
Application number: PCT/JP2019/032110
Authority: WO
Inventors: 裕章中山; 典佳原田; 正和武野; 妙中　真治; 俊介森安
Original assignee: 日本製鉄株式会社
Priority date: 2018-08-31
Filing date: 2019-08-16
Publication date: 2020-03-05
Also published as: JP2022120104A; JPWO2020045114A1; JP7143887B2

Abstract

A hat-shaped steel sheet pile comprising, in a cross-section orthogonal to the longitudinal direction: a web extending along the width direction on a first side in the depth direction; a pair of flanges extending to both sides in the width direction from both ends of the web in the width direction and towards a second side in the depth direction; a pair of arms extending from each end section of the pair of flanges, along the width direction on the second side in the depth direction and towards both sides in the width direction; and a mating fitting formed in an end section of each of the pair of arms, on the opposite side to the pair of flanges. The cross-sectional area Ae (cm²) of the hat-shaped steel sheet pile in the cross-section, the effective width W (cm) of the hat-shaped steel sheet pile, and the height H (cm) of the hat-shaped steel sheet pile fulfill the relationship in formula (i). The effective width W is at least 110 cm. Ae/(W·H) ≥ 0.04 … (i).

Description

Hat-shaped steel sheet pile and method of manufacturing steel sheet pile wall

The present invention relates to a hat-shaped steel sheet pile and a method for manufacturing a steel sheet pile wall.

形 Hat-shaped steel sheet piles are widely used in civil engineering and construction work to construct walls for earth retaining and waterproofing. Since a hat-shaped steel sheet pile is made to penetrate into the ground at the time of driving, a technique for improving workability by reducing penetration resistance has been proposed. For example, in Patent Literature 1, in the cross section of the hat-shaped steel sheet pile, the flange angle, that is, the flange is positioned between the web and the arm such that the intersection of a perpendicular passing through the center of each flange is located outside the groove cross section of the hat-shaped steel sheet pile. There is described a technique for improving the workability by suppressing the earth pressure at the time of placing by setting an angle to be formed. Patent Literature 2 also discloses a technique for minimizing the penetration resistance by optimizing the flange angle. Patent Literature 3 describes a technique for setting a flange angle based on an economic index and a workability index indicating a penetration resistance at the lower end of a steel sheet pile. Patent Literature 4 discloses at least one of economy and workability based on a relationship between an economy evaluation index and a workability evaluation index indicating a ratio of a cross-sectional area of a closing resistance acting on a lower end of a steel sheet pile at the time of driving. A technique for setting the cross-sectional shape of a steel sheet pile having excellent performance is described.

Japanese Patent No. 3488230 Japanese Patent No. 3488233 Japanese Patent No. 5764945 JP 2014-148798 A

All of the techniques described in Patent Documents 1 to 4 above focus on the behavior of steel sheet piles in the ground, and reduce the penetration resistance and blockage resistance acting after being made to penetrate the ground. The purpose is to improve workability. In other words, as a method of evaluating the workability of steel sheet piles, the focus has been on the mechanism of steel sheet pile insertion in the ground so far, and the optimum steel sheet pile is considered from the relationship with the ground resistance and soil particle behavior around the steel sheet pile. I've been looking for a sheet pile shape. However, according to the knowledge obtained by the present inventors, in addition to the behavior of the steel sheet pile in the ground, the behavior of the steel sheet pile on the ground portion during driving also affects the workability. In other words, in actual steel sheet pile driving, the situation where the steel sheet pile is being driven into the ground and the state where it is protruding above the ground proceed in a parallel fashion, and the workability of the steel sheet pile is It is affected by the coupled behavior of steel sheet piles inside and above the ground. Specifically, when a steel sheet pile is driven while being connected in the width direction by a joint, a cross section is applied to a hat-shaped steel sheet pile that is driven with the joint restrained by the steel sheet pile previously driven. It was found that the workability deteriorated due to the occurrence of torsional deformation.

Specifically, when deformation such as torsion or bending occurs in the hat-shaped steel sheet pile, the penetration resistance received from the ground from the bottom of the steel sheet pile at the lower end or from the side of the steel sheet pile at the time of driving, or the steel sheet pile previously driven There is a possibility that the fitting resistance with the joint increases. In addition, when deformation such as bending or torsion occurs in the hat-shaped steel sheet pile on the ground part, the construction machine such as a vibratory hammer tilts and swings, which originally causes the hat-shaped steel sheet pile to vibrate vertically. The vibration energy of the construction machine used in the construction may be lost as energy of horizontal vibration and rotation behavior of the hat-shaped steel sheet pile, and as a result, the penetration speed of the hat-shaped steel sheet pile into the ground may be reduced. When the construction machine is tilted or rocked, a horizontal load is applied to the steel sheet pile head, which increases the deflection and torsion behavior of the steel sheet pile, and further increases the loss of vibration energy. May fall into Therefore, in order to ensure good workability of the steel sheet pile, it is important to suppress not only the behavior in the ground but also the bending and torsional deformation of the steel sheet pile on the ground.

However, the behavior of the hat-shaped steel sheet pile on the ground portion, which may cause such deterioration in workability, is not described in Patent Documents 1 to 4 described above. In evaluating the driving performance of steel sheet piles, it has been conventional practice to look for not only the behavior in the ground but also the overall behavior of the steel sheet piles, including the ground part, and to search for the optimum steel sheet pile cross-sectional shape. Did not. One of the reasons is that, when the cross section of the steel sheet pile is small, the position at which the construction machine supports the steel sheet pile is not largely eccentric from the center of gravity of the cross section of the steel sheet pile, and therefore, the workability is affected at the ground part. This is because deformation such as bending and twisting of the steel sheet pile was difficult to occur. Therefore, the workability of steel sheet piles has been considered to be dominated by the resistance from the ground. In fact, if the steel sheet piles are small, the section deformation of the steel sheet piles at the time of driving is not significantly exposed on the ground, and no attention is paid to the relationship between the deformation behavior on the ground and the workability. However, there was no finding regarding the relationship between the two. However, in recent years, with the enlargement of the cross section of the hat-shaped steel sheet pile, the deformation behavior of the hat-shaped steel sheet pile in the ground portion, such as torsion and deflection, has been expanded, which may affect the workability.

Accordingly, the present invention provides a new and improved hat-shaped steel sheet pile and steel capable of improving workability by reducing torsional deformation in a cross section generated on a ground portion when the hat-shaped steel sheet pile is driven. An object of the present invention is to provide a method for manufacturing a sheet pile wall.

According to an aspect of the present invention, a hat-shaped steel sheet pile includes, in a cross section orthogonal to a longitudinal direction, a web extending along a width direction on a first side in a depth direction, and a width direction from both ends in a width direction of the web. And a pair of flanges extending toward the second side in the depth direction, and both ends in the width direction along the width direction from respective ends of the pair of flanges on the second side in the depth direction. And a mating joint formed at the end of each of the pair of arms opposite the pair of flanges. The sectional area Ae (cm ² ) of the hat-shaped steel sheet pile in the cross section, the effective width W (cm) of the hat-shaped steel sheet pile, and the height H (cm) of the hat-shaped steel sheet pile are represented by the following equation (i). Fill the relationship,
The effective width W is 110 cm or more.
Ae / (W · H) ≧ 0.04 (i)

In the above hat-shaped steel sheet pile, the effective width W may be 135 cm or more, and the height H may be 45 cm or less. Further, the cross-sectional area Ae (cm ² ), the effective width W (cm), and the height H (cm) in the cross section may satisfy the relationship of the following equation (ii).
Ae / (W · H) ≦ 0.048 (ii)

According to another aspect of the present invention, there is provided a method for manufacturing a steel sheet pile wall using the above hat-shaped steel sheet pile. The method of manufacturing the steel sheet pile wall is to cast a hat-shaped steel sheet pile into the ground while fitting only one of the fitting joints of the hat-shaped steel sheet pile to the fitting joint of the steel sheet pile previously placed. May be included.

According to the above configuration, the workability can be improved by reducing the torsional deformation in the cross section generated on the ground portion when the hat-shaped steel sheet pile is driven.

It is sectional drawing of the hat-shaped steel sheet pile which concerns on one Embodiment of this invention. It is a figure for demonstrating the fitting center in the fitting joint of the hat-shaped steel sheet pile shown in FIG. It is a figure which shows the boundary condition of a hat-shaped steel sheet pile at the time of driving, and is a figure for conceptually explaining the fitting state with a preceding sheet pile, and the holding state of a hat-shaped steel sheet pile with a vibro hammer. It is a figure for conceptually explaining horizontal torsional deformation which occurs in a hat-shaped steel sheet pile at the time of driving. Comparative Examples, Examples, and Reference Examples of the present invention are plotted with the effective width W as the horizontal axis and the ratio Ae / (W · H) of the cross-sectional area Ae to the product of the effective width W and the height H as the vertical axis. It is a graph. 6 is a graph in which only examples in which the effective width W is 135 cm or more are extracted from the examples shown in the graph of FIG. 5.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the specification and the drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a sectional view of a hat-shaped steel sheet pile according to one embodiment of the present invention. As shown in FIG. 1, a hat-shaped steel sheet pile 1 has a cross section orthogonal to a longitudinal direction (z direction in the figure) and a width direction on a first side in a depth direction (a depth side in a y direction in the figure). The web 2 extends along the x direction (in the figure) and from both ends in the width direction of the web 2 toward both sides in the width direction and toward the second side in the depth direction (front side in the y direction in the figure). The

flanges

3A and 3B extend and form a flange angle θ (a sharp angle side) with the width direction, and the widthwise direction from the respective ends of the

flanges

3A and 3B on the second side in the depth direction. 4A and 4B extending toward both sides of the arm 4A, and

fitting joints

5A and 5B formed at ends of the

arms

4A and 4B opposite to the

flanges

3A and 3B, respectively.

As will be described later, the cross-sectional area of the hat-shaped steel sheet pile 1 in this section (the area of the hatched area in the figure) Ae, the effective width W of the hat-shaped steel sheet pile 1, and the height H of the hat-shaped steel sheet pile 1 Satisfies the relationship of the following expression (1), and the effective width W is 110 cm or more. Incidentally, the effective width W, fitting joint 5A in cross-section, each of the mating centers _E A of 5B, equal to the distance between the _{E B.} The height H is the width of the hat-shaped steel sheet pile 1 on the first side (rear side in the y direction in the drawing) in the depth direction of the web 2 which coincides with the width direction of the hat-shaped steel sheet pile 1. The distance is equal to the distance between the

arms

4A and 4B in the depth direction on the second side (front side in the y direction in the drawing) that matches the direction.
Ae / (W · H) ≧ 0.04 (1)

The “surface on the second side in the depth direction of the

arms

4A and 4B” when defining the height H may not always exactly match the actual surfaces of the

arms

4A and 4B due to manufacturing errors and the like. is there. However, even in such a case, for example, in the cross section of the hat-shaped steel sheet pile 1 shown in the design drawing, the surfaces of the

arms

4A and 4B are on the same straight line, and this surface is referred to as “the depth direction of the

arms

4A and 4B”. Of the second side of the ". In this case, the extending direction of the

arms

4A and 4B shown in the design drawing coincides with the width direction of the hat-shaped steel sheet pile 1. Further, in the hat-shaped steel sheet pile 1 driven into the ground after the construction, due to the deformation of the

arms

4A and 4B during the construction and the like, for example, the "

arm

4A, 4A, The surface on the second side in the depth direction of 4B "may not always exactly coincide with the actual surfaces of the

arms

4A and 4B. However, also in this case, for example, the surfaces of the

arms

4A and 4B shown on the same straight line in the design drawing showing the situation before the driving are specified as "the surface on the second side in the depth direction of the

arms

4A and 4B". be able to. If that is not based on the design drawing, at the head end face of the hat-shaped steel sheet pile 1 exposed on the ground, the arm 4A, fitting center E _A located at each end of _4B, the arm 4A of the straight line connecting the E _B , 4B as a designed thickness center line, and this straight line is moved in parallel to the second side in the depth direction by half of the thickness of the

arms

4A, 4B to obtain the “second depth direction of the

arms

4A, 4B”. Side surface "can be specified.

When the shape of the hat-shaped steel sheet pile 1 shown in FIG. 1 is geometrically established, the arm length Ba, the effective width W, the web length Bw, the height H, and the flange angle θ are W−Bw− 2H / tan θ> 0.

FIG. 2 is a view for explaining a fitting center of the hat-shaped steel sheet pile shown in FIG. 1 in the fitting joint. As shown in the figure, the fitting joint 5B of another hat-shaped steel sheet pile 1 that is driven adjacent to the fitting joint 5B of the hat-shaped steel sheet pile 1 is fitted. Fitting center E _A fitting joint 5A, when placing the arms 4B and the fitting joint 5B fitted to virtually, and the end position of the arm 4A of the fitting joint 5A is formed, the virtual Can be defined as a point on the designed thickness center line of the arm 4A and the arm 4B, which is located in the middle of the end position of the arm 4B where the typical fitting joint 5B is formed. Fitting the center of the fitting joint 5B located on the opposite side of the hat-shaped steel sheet pile 1 E _B can also be defined similarly. As mentioned above, fitting the center E _A, the distance between the E _B is equal to the effective width W of the hat-shaped steel sheet pile 1.

および FIGS. 3 and 4 are diagrams for conceptually explaining the horizontal torsional deformation occurring in the hat-shaped steel sheet pile during driving. As shown in FIG. 3, the hat-shaped steel sheet pile 1 is driven by a vertical load applied from a vibro hammer 6 sandwiching the

flanges

3A and 3B at the upper end. In order to stably support the hat-shaped steel sheet pile 1, the vibratory hammer 6 is arranged so that the position in the depth direction (the y direction in the drawing) substantially matches the center C of the cross section.

Here, there is a hat-shaped steel sheet pile 1P previously driven near the ground surface, and the hat-shaped steel sheet pile 1 is driven while the fitting joint 5A is fitted to the fitting joint 5B of the hat-shaped steel sheet pile 1P. Is established. Therefore, near the ground surface, the fitting joint 5A of the hat-shaped steel sheet pile 1 is restrained from horizontal displacement by the fitting joint 5B of the hat-shaped steel sheet pile 1P. Mating fitting 5A is constrained to horizontal displacement by contact at a plurality of points near the fitting joint 5B and the fitting center E _A. Therefore, the hat-shaped steel sheet pile 1 is restrained by the fitting joint portion and the ground at the lower portion in the longitudinal direction projecting to the ground portion. On the other hand, since the centroid C, which is the point of application of the load by the vibro-hammer 6, is located away from the constraint point of the horizontal displacement as described above, the hat-shaped steel sheet pile 1 is bent in the direction of twisting the cross section. A moment is generated.

Here, the distance between the fitting center E _A and centroid C is different between and the depth direction (x direction in the drawing) the width direction of the hat-shaped steel sheet pile 1 (y direction in the drawing), The magnitude of the bending moment generated in each direction is different. In addition, since the secondary moment of area of the hat-shaped steel sheet pile 1 in each direction is also different, a difference occurs in the bending generated in each direction, and torsional deformation occurs in the cross section. Since the upper end and the lower end of the hat-shaped steel sheet pile 1 are respectively restrained by the vibratory hammer 6 and the ground, pure torsion is predominantly generated in the hat-shaped steel sheet pile 1 as compared with the warped torsion due to the bending moment. As shown in FIG. 4, the torsion angle φ of pure torsion about an arbitrary point in the cross section of the hat-shaped steel sheet pile 1 is represented by the following equation (2). Here, Mt is the bending moment around the center of pure torsion, G is the shear modulus of elasticity of the hat-shaped steel sheet pile 1, and J is the torsional moment of the cross section of the hat-shaped steel sheet pile 1.
φ = Mt / (G · J) (2)

Generally, the

fittings

5A and 5B are designed to allow a certain degree of twist angle φ. However, when φ increases, the friction generated between the fitting joint 5A of the hat-shaped steel sheet pile 1 to be driven and the fitting joint 5B of the hat-shaped steel sheet pile 1P previously driven is increased. As a result, the

fitting joints

5A and 5B may be damaged, or the resistance at the time of driving may be increased, thereby deteriorating the workability.

Here, from the economical viewpoint of the cross section of the hat-shaped steel sheet pile 1, it is advantageous to increase the effective width W and make it thinner. However, when the thickness is reduced, the sectional area that resists the bending moment decreases, the sectional torsional moment that resists the bending moment decreases, the torsional rigidity decreases, and the torsional angle φ increases accordingly. Therefore, it is effective to secure a cross-sectional area of a certain value or more. When the effective width W is increased, the torsional moment in section is determined by the thickness of the web 2, the

flanges

3A and 3B, and the

arms

4A and 4B within the effective width and height occupied by the single hat-shaped steel sheet pile 1. Although it is necessary to secure J, it is desirable that there is a simple index indicating how much the thickness is required, because the economics of the cross section decreases when the thickness is increased.

In view of the above points, the present inventors have developed a hat-shaped steel sheet pile 1 capable of reducing the torsion angle φ from that of the conventional hat-shaped steel sheet pile while increasing the effective width W of the hat-shaped steel sheet pile. The index of the cross-sectional shape of the hat, as a hat-shaped steel sheet pile, the displacement in the longitudinal direction is fixed at the upper and lower ends of the longitudinal direction, the pure torsion to the thin open cross section against the moment to rotate the cross section around the longitudinal axis direction The study was conducted by applying a state occurring on the ground portion in the longitudinal direction of the shaped sheet pile 1. The following considerations are based on the cross-sectional area Ae as a parameter reflecting the thickness of the web 2, the

flanges

3A and 3B, and the

arms

4A and 4B, and the effective width of the hat-shaped steel sheet pile 1 as a parameter reflecting the magnitude of the bending moment Mt. By using W and the height H, it is intended to easily specify the condition of the cross-sectional shape of the hat-shaped steel sheet pile 1 capable of reducing the torsion angle φ.

Tables 1 to 4 show the results of the study. Study, geometrical moment of inertia _{I W} is 10000 cm ⁴ / m level per wall width 1m of wall linked a hat-shaped steel sheet pile 1 in the width direction, 25000 cm ⁴ / m level, 45000cm ⁴ / m level, and 50000 cm ⁴ / M level, and Examples 1 to 21 in which the torsion angle φ is smaller than those of the conventional hat-shaped steel sheet piles shown as Comparative Examples 1 to 4 are referred to as conventional hat-shaped steel sheet piles. Examples in which the torsion angle φ is larger than that of the sheet pile are shown as Reference Examples 1 to 14, respectively. As described above, in the present embodiment, since the effective width W is intended to be larger than that of the conventional hat-shaped steel sheet pile, the effective widths of the hat-shaped steel sheet piles 1 are all described in Examples 1 to 21. W is 110 cm or more. The dimensions represented by the web thickness tw (cm), the web width Bw (cm), and the arm width Ba (cm) shown in Tables 1 to 4 are shown in FIG. As described above, when the effective width W of the hat-shaped steel sheet pile 1 is increased in order to satisfy the performance as a steel sheet pile with less torsion and to pursue economical advantages as compared with the conventional hat-shaped steel sheet pile, From the viewpoint of performance and the like, in order to secure productivity, it is desirable that the height H be within a small range with respect to the effective width W, and a cross section in which the height is suppressed to 45 cm or less is pursued. Therefore, the height H in Examples 1 to 21 is 45 cm or less (the largest is H = 40.2 cm in Example 21). Even if the effective width is large and the height is low, the aim is to form a cross section that satisfies predetermined torsional performance by setting the ratio of the cross-sectional area to the effective width and height within a predetermined range.

FIG. 5 shows the above Comparative Examples 1 to 4, Examples 1 to 21, and Reference Examples 1 to 14 by plotting the effective width W (cm) on the horizontal axis, the cross-sectional area Ae and the effective width W. It is the graph which plotted the ratio Ae / (W.H) with the product of the height H as a vertical axis.

Here, an index using the cross-sectional specification of the hat-shaped steel sheet pile set as the axis of the graph of FIG. 5 will be described. Bending moment generates a torsion hat-shaped steel sheet pile is increased in proportion to the width direction and the depth direction respective distances between the mating centers E _A and centroid C. The magnitude of the torsion angle φ is proportional to the bending moment and inversely proportional to the sectional torsion moment. Therefore, reference to the size of the bending moment, as an index representing the width direction and the depth direction respective distances between the mating centers E _A and centroid C, with an effective width W and height H of the steel sheet pile section, both The product of both indices was used to simultaneously include the effects of the indices. The cross-sectional area Ae was used as an index indicating the magnitude of the torsional moment of area.

In order to make the cross section area Ae of the steel sheet pile economical within the range of the predetermined rollable area, it is preferable that the cross section area Ae of the steel sheet pile relative to the area is small. The predetermined area that can be rolled is proportional to the product of the effective width W and the height H, which is the final shape of the rolled steel sheet pile. Therefore, Ae / (W · H) is one index indicating the economics of the steel sheet pile cross section. That is, Ae / (W · H) can be an index for determining the magnitude of the torsion angle φ as described above, and can also be an index for evaluating economic efficiency. In the graph of FIG. 5, the vertical axis is Ae / (W · H), which is a simple index that can evaluate two indexes only with the three items of the cross-sectional area Ae, the effective width W, and the height H.

Specifically, it is advantageous to increase the value of Ae / (W · H) in order to reduce the torsion angle φ, and in order to obtain an economical cross section, Ae / (W · H) It is advantageous to reduce the value of. In other words, if the value of Ae / (W · H) is too large, the torsion angle φ becomes small, but the economic efficiency deteriorates. Conversely, if the value of Ae / (W · H) is too small, the economic efficiency becomes low. Although good, the torsion angle φ increases. By using the index of Ae / (W · H), it is possible to balance the reduction of the torsion angle φ and the economy, that is, to easily determine both the workability and the economy at the same time.

On the other hand, to make the hat-shaped steel sheet pile economical in cross section, it is effective to increase the width. This is because the web width can be increased and the area ratio of the flange portion to the predetermined width can be reduced, so that the secondary moment of area per predetermined width, that is, bending rigidity, can be secured with a smaller cross-sectional area. Therefore, in the graph of FIG. 5, the effective width W is plotted on the horizontal axis in view of evaluating the economic efficiency with respect to bending rigidity.

In the graph of FIG. 5 as described above, Comparative Examples 1 to 4 are shown as points P1 to P4, Examples 1 to 21 are shown as points E1 to E21, and Reference Examples 1 to Reference Example 14 is shown divided into groups of points R1, R11 to R14 and points R2 to R10. Points E1 to E21 indicating the examples are included in the range of Ae / (W · H) ≧ 0.04. On the other hand, points R2 to R10 indicating the reference example are in the range of Ae / (W · H) <0.04. On the other hand, points P1 to P4 indicating the comparative example and points R1 and R11 to R14 indicating the reference example are in the range of W <110 cm. Therefore, from the above results, the following equation (1) can be specified as a condition of the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the torsion angle φ when the effective width W is 110 cm or more.
Ae / (W · H) ≧ 0.04 (1)

Here, it is preferable that the hat-shaped steel sheet pile having a so-called thin-walled large-section having an increased width is formed to have a more compact section in consideration of manufacturability. In this respect, among the embodiments discussed above, those second moment I _W per wall width 1m of wall linked a hat-shaped steel sheet pile 1 in the width direction below 25000 cm 4 / ^m level, performed Examples 1 to 8 are more preferred. In Examples 1 to 8, the following expression (2) is satisfied in addition to the above expression (1).
Ae / (W · H) ≦ 0.048 (2)

FIG. 6 is a graph in which only the wider examples having an effective width W of 135 cm or more are extracted from Examples 1 to 21 shown in the graph of FIG. Specifically, Examples 2 to 7, Example 13 to Example 18, Example 20, and Example 21 are extracted. Like the graph of FIG. 5, also in the graph of FIG. 6, the points E2 to E7, E13 to E18, E20, and E21 are included in the range of Ae / (W · H) ≧ 0.04. Here, as shown in Tables 1, 3 and 4, the effective width W of Examples 2 to 7, Example 13 to Example 18, Example 20, and Example 21 was 135 cm. In addition to the above, the torsion angle φ (ratio to the conventional one) is reduced to less than 0.95, that is, to less than 95% of the conventional hat-shaped sheet pile, and the torsion angle φ is reduced more than other examples. Is also a large example. The torsional deformation that occurs in the hat-shaped steel sheet pile during casting impairs the fitting property of the hat-shaped steel sheet pile previously driven into the ground with the joint. Here, the tolerance of the fitting angle of the hat-shaped steel sheet pile joint is usually manufactured in a very narrow range of ± 4 degrees or less, and even if the torsion angle difference between cross sections at different depths in a certain longitudinal direction. Is less than 1 degree, the amount of torsion is accumulated in the longitudinal direction of the hat-shaped steel sheet pile, which tends to increase the fitting resistance. Therefore, it is useful to reduce the amount of torsion even if the amount is very small. However, if the amount of torsion can be reduced even by 5%, for example, the torsional deformation during the driving of a hat-shaped steel sheet pile to be driven later is performed. Therefore, the contact resistance between the preceding steel sheet pile and the joint can be further reduced, and the effect on the workability can be reduced more effectively. Therefore, the above equation (1) indicates that the torsion angle φ (compared to the prior art) is less than 0.95, and the cross section of the hat-shaped steel sheet pile 1 having an effective width W of 135 cm or more can significantly reduce the torsion angle φ. It can be applied more advantageously as a shape condition.

According to the embodiment of the present invention as described above, a hat-shaped steel sheet pile having a cross-sectional shape in which torsional deformation in a cross-section generated at the time of driving is effectively reduced is provided. Such a hat-shaped steel sheet pile is formed, for example, by fitting only one of a pair of fitting joints of the hat-shaped steel sheet pile to a fitting joint of a steel sheet pile previously driven. The method is particularly advantageous in a method for manufacturing a steel sheet pile wall including a step of placing the sheet pile in the ground. In such a method for manufacturing a steel sheet pile wall, the construction machine supports the steel sheet pile at a position where one joint of the hat-shaped steel sheet pile is fitted to the joint of the steel sheet pile previously driven. Since the position where the vertical vibration load is applied is eccentric, a moment that causes torsional deformation occurs in the hat-shaped steel sheet pile, but torsional deformation can be effectively suppressed by applying the embodiment of the present invention.

By suppressing the torsional deformation of the hat-shaped steel sheet pile, it is transmitted to the hat-shaped steel sheet pile in a state in which the construction energy from the construction machine is efficiently used with little loss and the heavy construction power is used, and the hat-shaped steel sheet pile enters the ground. The penetration speed can be kept high, and the fuel-efficient and economical construction of the heavy construction machine becomes possible. In addition, by suppressing the torsional deformation of the hat-shaped steel sheet pile, the flapping of the hat-shaped steel sheet pile during casting is reduced, and noise and vibration accompanying construction can be reduced. Noise and vibration may increase when the construction machine is enlarged due to the large cross section of the hat-shaped steel sheet pile, but by suppressing torsional deformation of the hat-shaped steel sheet pile, it is possible to perform construction with reduced noise and vibration. Become.

In addition, by suppressing the torsional deformation of the hat-shaped steel sheet pile, the fitting resistance of the steel sheet pile previously driven into the joint can be reduced. Can be reduced, and scraping and welding at the contact surface of the joint can be prevented.

Although the preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive various changes or modifications within the scope of the technical idea described in the claims. It is understood that these also belong to the technical scope of the present invention.

1 ... hat-shaped steel sheet pile, 2 ... web, 3A, 3B ... flange, 4A, 4B ... arm, 5A, 5B ... fitting joint, 6 ... vibro-hammer over, _{E A,} E B _... fitting center.

Claims

A hat-shaped steel sheet pile,
In a cross section orthogonal to the longitudinal direction, a web extending along the width direction on the first side in the depth direction, and both ends in the width direction from both ends in the width direction of the web, and the second side in the depth direction A pair of flanges extending from the respective ends of the pair of flanges on the second side in the depth direction along the width direction and toward both sides in the width direction. An arm, and a fitting joint formed at an end of each of the pair of arms opposite to the pair of flanges;
The sectional area Ae (cm 2 ) of the hat-shaped steel sheet pile in the cross section, the effective width W (cm) of the hat-shaped steel sheet pile, and the height H (cm) of the hat-shaped steel sheet pile are represented by the following equations. A hat-shaped steel sheet pile that satisfies the relationship (i) and has an effective width W of 110 cm or more.
Ae / (W · H) ≧ 0.04 (i)
ハ The hat-shaped steel sheet pile according to claim 1, wherein the effective width W is 135 cm or more.
The hat-shaped steel sheet pile according to claim 1 or 2, wherein the height H is 45 cm or less.
The said sectional area Ae (cm < 2 >) in the said cross section, the said effective width W (cm), and the said height H (cm) satisfy | fill the relationship of following formula (ii). The hat-shaped steel sheet pile according to any one of the above.
Ae / (W · H) ≦ 0.048 (ii)
A method for manufacturing a steel sheet pile wall using the hat-shaped steel sheet pile according to any one of claims 1 to 4,
A steel including a step of driving the hat-shaped steel sheet pile into the ground while fitting only one of the fitting joints of the hat-shaped steel sheet pile to the fitting joint of the steel sheet pile previously driven. Manufacturing method of sheet pile wall.