JP7143887B2 - Manufacturing method of hat-shaped steel sheet pile - Google Patents

Description

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

Hat-shaped steel sheet piles are widely used in civil engineering and construction work to build walls for retaining earth and stopping water. Since hat-shaped steel sheet piles are forced to penetrate into the ground during placement, techniques have been proposed to improve workability by reducing the penetration resistance. For example, in Patent Document 1, the flange angle, that is, the distance between the web and the arm, is such that the intersection of the perpendicular lines passing through the centers of the respective flanges in the cross section of the hat-shaped steel sheet pile is positioned outside the groove cross section of the hat-shaped steel sheet pile. It describes a technique for improving workability by suppressing the pressure of soil discharge during placing by setting the angle to be made to . Patent Literature 2 also describes a technique for minimizing penetration resistance by optimizing the flange angle. Further, Patent Literature 3 describes a technique for setting the flange angle based on an economic index and a workability index that indicates the penetration resistance at the lower end of the steel sheet pile. Patent Document 4 describes at least one of economic efficiency and workability based on the relationship between the economic evaluation index and the workability evaluation index that indicates the ratio of the clogging resistance acting on the lower end of the steel sheet pile during placement to the cross-sectional area. A technique for setting the cross-sectional shape of a steel sheet pile with 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 Document 1 to Patent Document 4 above focus on the behavior of steel sheet piles in the ground, and reduce the penetration resistance and blockage resistance that act after they are penetrated into the ground. The purpose is to improve workability by In other words, as a method to evaluate the workability of steel sheet piles, until now, we have focused only on the mechanism when steel sheet piles are inserted into the ground, and from the relationship with the soil resistance and soil particle behavior around the steel sheet pile, we have determined the optimum 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 such steel sheet piles in the ground, the behavior of the steel sheet pile on the ground during placement also affects workability. In other words, in the actual driving of steel sheet piles, the situation in which the steel sheet piles are driven into the ground and the situation in which they protrude above the ground proceed in parallel. It is affected by the coupled behavior of steel sheet piles inside and aboveground. Specifically, when the steel sheet piles are driven while being connected in the width direction by joints, the cross-sectional view of the hat-shaped steel sheet pile that is driven while the joints are restrained by the previously driven steel sheet pile. It was found that the workability deteriorated due to the torsional deformation of the

Specifically, when a hat-shaped steel sheet pile undergoes deformation such as torsion or deflection, penetration resistance received from the ground below the bottom end of the steel sheet pile or from the side of the steel sheet pile during driving, Engagement resistance with the joint may increase. In addition, when deformation such as bending or twisting occurs in the hat-shaped steel sheet pile on the ground, the construction machine such as the vibro hammer tilts and swings, which originally causes the hat-shaped steel sheet pile to vibrate in the vertical direction. Vibrational energy of the construction machine used for this is lost as energy of horizontal vibration and rotational behavior of the hat-shaped steel sheet pile, and as a result, there is a possibility that the penetrating speed of the hat-shaped steel sheet pile into the ground decreases. If the construction machine tilts or swings, a horizontal load is applied to the head of the steel sheet pile, which increases the bending and twisting behavior of the steel sheet pile, further increasing the loss of vibration energy, creating a vicious circle. may fall into Therefore, in order to ensure good workability of steel sheet piles, it is important to suppress deflection and torsional deformation of steel sheet piles not only in the ground but also on the ground.

However, Patent Documents 1 to 4 do not describe the behavior of the hat-shaped steel sheet pile on the ground, which can cause such deterioration in workability. In order to evaluate the driving performance of steel sheet piles, it has been conventional practice to search for the optimum cross-sectional shape of steel sheet piles by looking not only at the behavior in the ground but also at the ground and the behavior of the entire steel sheet pile. I didn't. One of the reasons for this is that when the cross section of the steel sheet pile is small, the position where the construction machine supports the steel sheet pile does not deviate greatly from the center of gravity of the cross section of the steel sheet pile. This is because deformation such as bending and twisting of steel sheet piles 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 pile is small, the cross-sectional deformation of the steel sheet pile at the time of placing is not conspicuously exposed on the ground, and the relationship between the deformation behavior on the ground and workability is not focused. , there was no knowledge of the relationship between the two. However, in recent years, as the cross section of hat-shaped steel sheet piles has increased, the deformation behavior of the hat-shaped steel sheet piles on the ground, such as torsion and deflection, has increased, which may affect workability.

Therefore, the present invention provides a new and improved hat- shaped steel sheet pile that can improve workability by reducing torsional deformation in the cross section that occurs in the above-ground portion when the hat-shaped steel sheet pile is placed. It aims at providing the manufacturing method of.

According to one aspect of the present invention, the hat-shaped steel sheet pile includes, in a cross section orthogonal to the longitudinal direction, a web extending along the width direction on a first side in the depth direction, and a and a pair of flanges extending toward the second side in the depth direction, along the width direction from each end of the pair of flanges on the second side in the depth direction, and on both sides in the width direction and a mating joint formed at the end of each of the pair of arms opposite to the pair of flanges. The cross-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 given by the following formula (i): satisfy relationships,
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. Also, 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 formula (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 manufacturing method of the steel sheet pile wall includes 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 previously driven steel sheet pile. may include the step of

According to the above configuration, it is possible to improve the workability by reducing the torsional deformation in the cross section that occurs in the ground portion when the hat-shaped steel sheet pile is placed.

1 is a cross-sectional view of a hat-shaped steel sheet pile according to an embodiment of the present invention; FIG. 1. It is a figure for demonstrating the fitting center in the fitting joint of the hat-shaped steel sheet pile shown by FIG. FIG. 4 is a diagram for conceptually explaining a fitting state with a preceding sheet pile and a gripping state of the hat-shaped steel sheet pile by a vibro-hammer, showing boundary conditions of the hat-shaped steel sheet pile during driving. FIG. 4 is a diagram for conceptually explaining horizontal torsional deformation that occurs in the hat-shaped steel sheet pile during placement. The comparative examples, examples, and reference examples of the present invention were plotted with the effective width W on 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 on the vertical axis. graph. FIG. 6 is a graph showing only examples with an effective width W of 135 cm or more extracted from the examples shown in the graph of FIG. 5 ; FIG.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

FIG. 1 is a cross-sectional view of a hat-shaped steel sheet pile according to one embodiment of the present invention. As shown in FIG. 1, the hat-shaped steel sheet pile 1, in a cross section orthogonal to the longitudinal direction (the z direction in the figure), has a width direction on the first side in the depth direction (back side in the y direction in the figure). A web 2 extending 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 the second side in the depth direction (the front side in the y direction in the figure) Flanges 3A and 3B extend and form a flange angle θ (acute angle side) with the width direction, and along the width direction from each end of the flanges 3A and 3B on the second side in the depth direction, and in the width direction and fitting joints 5A, 5B formed at the ends of the arms 4A, 4B opposite the flanges 3A, 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 region 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 formula (1), and the effective width W is 110 cm or more. Note that the effective width W is equal to the distance between the fitting centers E _A and E _B of the fitting joints 5A and 5B in cross section. In addition, the height H is the width It is equal to the distance between the second side in the depth direction (front side in the y direction in the figure) of the arms 4A and 4B that match the direction.
Ae/(W·H)≧0.04 (1)

It should be noted that the "surfaces on the second side in the depth direction of the arms 4A and 4B" when defining the height H may not strictly match the actual surfaces of the arms 4A and 4B due to manufacturing errors and the like. be. 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 planes of the arms 4A and 4B are on the same straight line, and this plane is called the "depth direction of the arms 4A and 4B." can be identified as "the surface on the second side of". 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 . In addition, in the hat-shaped steel sheet pile 1 driven into the ground after construction, due to deformation of the arms 4A and 4B during construction, for example, the head end surface of the hat-shaped steel sheet pile 1 exposed above the ground "arm 4A, 4B in the depth direction" may not necessarily exactly match the actual surfaces of the arms 4A and 4B. However, even in this case, for example, the planes of the arms 4A and 4B shown on the same straight line in the design drawing showing the situation before placing are specified as "the planes on the second side in the depth direction of the arms 4A and 4B." be able to. If it is not based on the design drawing, on the head end surface of the hat-shaped steel sheet pile 1 exposed on the ground, a straight line connecting the fitting centers EA and _EB located at the respective ends of the arms 4A and _4B is drawn as the arm 4A. , 4B, and by translating this straight line to the second side in the depth direction by half the thickness of the arms 4A and 4B, the second depth direction of the arms 4A and 4B is obtained. side surface" can be specified.

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

FIG. 2 is a diagram for explaining the fitting center in the fitting joint of the hat-shaped steel sheet pile shown in FIG. As illustrated, the fitting joint 5A of the hat-shaped steel sheet pile 1 is fitted with the fitting joint 5B of another hat-shaped steel sheet pile 1 driven adjacently. The fitting center _EA of the fitting joint 5A is the end position of the arm 4A where the fitting joint 5A is formed when the arm 4B and the fitting joint 5B to be fitted thereto are arranged virtually, and the imaginary It can be defined as a point on the design plate thickness centerline of arms 4A and 4B that is located midway between the end position of arm 4B at which fitting joint 5B is formed. The fitting center EB of the fitting joint _5B located on the opposite side of the hat-shaped steel sheet pile 1 can be similarly defined. As described above, the distance between the engagement centers E _A and E _B is equal to the effective width W of the hat-shaped steel sheet pile 1 .

3 and 4 are diagrams for conceptually explaining horizontal torsional deformation that occurs in the hat-shaped steel sheet pile during placement. As shown in FIG. 3, the hat-shaped steel sheet pile 1 is driven by a vertical load applied from the vibro-hammers 6 sandwiching the flanges 3A and 3B at their upper ends. In order to stably support the hat-shaped steel sheet pile 1, the vibro-hammer 6 is arranged such that the position in the depth direction (the y direction in the drawing) substantially coincides with the centroid C of the cross section.

Here, there is a hat-shaped steel sheet pile 1P that has been driven in advance near the ground surface, and the hat-shaped steel sheet pile 1 is driven while fitting the fitting joint 5A to the fitting joint 5B of the hat-shaped steel sheet pile 1P. is set. 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. The fitting joint 5A is restrained from horizontal displacement by contacting the fitting joint 5B at a plurality of points in the vicinity of the fitting center _EA . Therefore, the hat-shaped steel sheet pile 1 is restrained by the fitting joint portion and the ground at the longitudinally lower portion that protrudes above the ground. 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 constraining point of the horizontal displacement as described above, the hat-shaped steel sheet pile 1 does not bend in the direction of twisting the cross section. Moments occur.

Here, since the distance between the fitting center EA and the centroid _C differs between the width direction (x direction in the drawing) and the depth direction (y direction in the drawing) of the hat-shaped steel sheet pile 1, The magnitude of the bending moment generated in each direction is different. In addition, since the cross-sectional moment of inertia of the hat-shaped steel sheet pile 1 in each direction is also different, a difference in deflection occurs in each direction, and torsional deformation occurs in the cross section. Since the upper and lower ends of the hat-shaped steel sheet pile 1 are constrained by the vibro-hammer 6 and the ground, respectively, pure torsion is predominantly generated in the hat-shaped steel sheet pile 1 compared to warp torsion due to the above bending moment. As shown in FIG. 4, the torsion angle φ of pure torsion centered on an arbitrary point in the cross section of the hat-shaped steel sheet pile 1 is expressed by the following equation (2). Mt is the bending moment of pure torsion around the center, G is the shear elastic modulus of the hat-shaped steel sheet pile 1, and J is the sectional torsional moment of the hat-shaped steel sheet pile 1.
φ=Mt/(G・J) (2)

In general, the mating joints 5A, 5B are designed to allow a certain degree of torsion 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 driven in advance increases. As a result, there is a possibility that the fitting joints 5A and 5B will be damaged, or that the workability will be reduced due to an increase in the resistance at the time of placing.

Here, from the viewpoint of economic efficiency of the cross section of the hat-shaped steel sheet pile 1, it is advantageous to increase the effective width W and reduce the thickness. However, if the thickness is reduced, the cross-sectional area that resists the bending moment decreases, the cross-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 certain or more cross-sectional area. When expanding the effective width W, within the range of the effective width and height occupied by the single hat-shaped steel sheet pile 1, the cross-sectional torsional moment It is necessary to secure J, but if the plate thickness is increased, the economic efficiency of the cross section is lowered.

In view of the above points, the present inventors have developed a hat-shaped steel sheet pile 1 that can reduce the torsion angle φ more than that of a conventional hat-shaped steel sheet pile while increasing the effective width W more than that of a conventional hat-shaped steel sheet pile. A hat-shaped steel sheet pile is used as an indicator of the cross-sectional shape, and the displacement in the longitudinal direction is fixed at the upper and lower ends of the longitudinal direction. A study was made by applying the state occurring in the ground part in the longitudinal direction of the section steel sheet pile 1 . In the following examination, the effective width of the hat-shaped steel sheet pile 1 as a parameter reflecting the thickness of the web 2, the flanges 3A and 3B, and the arms 4A and 4B is the cross-sectional area Ae, and the parameter reflecting the magnitude of the bending moment Mt is By using W and height H respectively, it is intended to simply specify the conditions of the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the torsion angle φ.

Tables 1 to 4 show the results of the study. In the study, the geometrical moment of inertia _IW per wall width of 1 m of the wall connecting the hat-shaped steel sheet piles 1 in the width direction was 10000 cm ⁴ /m level, 25000 cm ⁴ /m level, 45000 cm ⁴ /m level, and 50000 cm ⁴ /m level, and examples in which the torsion angle φ is reduced as compared to the conventional hat-shaped steel sheet piles shown as Comparative Examples 1 to 4 are given as Examples 1 to 21, and conventional hat-shaped steels 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, the effective width W of the hat-shaped steel sheet pile is intended to be wider than that of the conventional hat-shaped steel sheet pile. W is 110 cm or more. Also, the dimensions represented by the web thickness tw (cm), web width Bw (cm), and arm width Ba (cm) shown in Tables 1 to 4 are shown in FIG. As described above, when expanding the effective width W of the hat-shaped steel sheet pile 1 in order to satisfy the performance as a steel sheet pile with less twisting compared to the conventional hat-shaped steel sheet pile and to pursue economic merits, In order to ensure productivity from the viewpoint of performance, etc., it is desirable that the height H be within a range smaller than the effective width W, and a cross section with a height of 45 cm or less is pursued. Therefore, in Examples 1 to 21, the height H is 45 cm or less (the largest being H=40.2 cm in Example 21). Even if the effective width is wide and the height is low, by setting the ratio of the cross-sectional area to the effective width and height within a predetermined range, it aims to form a cross section that satisfies a predetermined torsion resistance performance.

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

Here, the index using the cross-sectional dimensions of the hat-shaped steel sheet pile set as the axis of the graph in FIG. 5 will be described. The bending moment that causes the torsion of the hat-shaped steel sheet pile increases in proportion to the distance between the fitting center EA and the centroid _C in the width direction and the depth direction. The magnitude of the torsion angle φ is proportional to the bending moment and inversely proportional to the cross-sectional torsion moment. Therefore, regarding the magnitude of the bending moment, the effective width W and height H of the cross section of the steel sheet pile are used as indices representing the respective distances in the width direction and depth direction between the fitting center _EA and the centroid C. The product of both measures was used to include the effects of both measures simultaneously. Moreover, the cross-sectional area Ae was used as an index representing the magnitude of the cross-sectional torsional moment.

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

Specifically, in order to reduce the torsion angle φ, it is advantageous to increase the value of Ae/(W·H). A small value of is advantageous. In other words, if the value of Ae/(W H) is too large, the torsion angle φ becomes small, but the economy deteriorates. The torsion angle φ becomes large although the result is good. By using the index of Ae/(W·H), it is possible to achieve a balance between the reduction of the torsion angle φ and economic efficiency, that is, both workability and economic efficiency can be easily determined at the same time.

On the other hand, in order to make the cross section of the hat-shaped steel sheet pile economical, it is effective to increase the width. This is because the web width can be increased and the ratio of the area of the flange portion to the predetermined width can be reduced, so that the second moment of area per predetermined width, that is, the 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, taking into consideration the evaluation of the economic efficiency with respect to the 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-R14 and points R2-R10. Points E1 to E21 indicating the embodiment are included in the range of Ae/(W·H)≧0.04. On the other hand, the points R2 to R10 representing 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 formula (1) can be specified as a condition for 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, the so-called thin-walled, large-section hat-shaped steel sheet pile with increased width is preferably made to have a more compact section in consideration of manufacturability. From this point of view, among the examples examined above, those in which the geometrical moment of inertia _IW per 1 m of wall width of the wall connecting the hat-shaped steel sheet piles 1 in the width direction is 25000 cm ⁴ /m level or less, that is, the implementation Examples 1-8 are more preferred. In Examples 1 to 8, the following formula (2) is satisfied in addition to the above formula (1).
Ae/(W·H)≦0.048 (2)

FIG. 6 is a graph in which only examples with a wider 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, Examples 13 to 18, Example 20, and Example 21 are extracted. As in the graph of FIG. 5, points E2 to E7, E13 to E18, E20, and E21 are included in the range of Ae/(W·H)≧0.04 in the graph of FIG. Here, as shown in Tables 1, 3, and 4 above, Examples 2 to 7, Examples 13 to 18, Example 20, and Example 21 have an effective width W of 135 cm. In addition to the above, the torsion angle φ (compared to the conventional one) is reduced to less than 0.95, that is, less than 95% of the conventional hat-shaped steel sheet pile, and the reduction range of the torsion angle φ is greater than that of other examples. is also a large example. The torsional deformation that occurs in the hat-shaped steel sheet pile during driving deteriorates the fitability with the joint of the hat-shaped steel sheet pile that has been previously driven into the ground. Here, the fitting angle tolerance of the hat-shaped steel sheet pile joint is usually manufactured within a very narrow range of ±4 degrees or less. is less than 1 degree, the torsion amount is accumulated in the longitudinal direction of the hat-shaped steel sheet pile, which tends to lead to an increase in fitting resistance. Therefore, it is useful to reduce the amount of twist even by a very small amount. It is possible to further reduce the contact resistance between the preceding steel sheet pile and the joint associated with this, and it is possible to more effectively reduce the effect on workability. Therefore, the above formula (1) is a cross-section that can significantly reduce the torsion angle φ for the hat-shaped steel sheet pile 1 with an effective width W of 135 cm or more, where the torsion angle φ (compared to the conventional one) is less than 0.95. It can be applied more advantageously as a shape condition.

According to the embodiments of the present invention as described above, there is provided a hat-shaped steel sheet pile with a cross-sectional shape that effectively reduces torsional deformation in the cross-section that occurs during placement. Such a hat-shaped steel sheet pile is manufactured, for example, by fitting only one of a pair of fitting joints of the hat-shaped steel sheet pile to the fitting joint of the previously driven steel sheet pile. It is particularly advantageous in a method of manufacturing a steel sheet pile wall that includes driving into the ground. In this method of 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 previously driven steel sheet pile. Since the position where the vertical vibration load is applied is eccentric, a moment that causes torsional deformation is likely to occur in the hat-shaped steel sheet pile, but by applying the embodiment of the present invention, torsional deformation can be effectively suppressed.

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 heavy functional force is efficiently utilized with little driving energy loss from the construction machine, and into the ground of the hat-shaped steel sheet pile. It is possible to maintain a high penetration speed and achieve economical construction with good fuel efficiency of construction heavy machinery. In addition, by suppressing the torsional deformation of the hat-shaped steel sheet pile, the flapping of the hat-shaped steel sheet pile during driving is reduced, and noise and vibration accompanying construction can be reduced. Larger cross-sections of hat-shaped steel sheet piles may increase the size of the construction machine, but noise and vibration may also increase. Become.

In addition, by suppressing the torsional deformation of the hat-shaped steel sheet pile, it is possible to reduce the fitting resistance of the previously driven steel sheet pile with the joint, so that the resistance during driving of the entire hat-shaped steel sheet pile can be reduced. can be reduced, and scraping and welding on the contact surface of the joint can be prevented.

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications 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.

DESCRIPTION OF SYMBOLS 1... Hat-shaped steel sheet pile, 2... Web, 3A, 3B... Flange, 4A, 4B... Arm, 5A, _5B ... Fitting joint, 6... Vibro hammer, EA, _EB ... Fitting center.

Claims (1)

A method for manufacturing a hat-shaped steel sheet pile,
In a cross section orthogonal to the longitudinal direction, the hat-shaped steel sheet pile includes a web extending along the width direction on a first side in the depth direction, both sides in the width direction from both ends of the web in the width direction, and the a pair of flanges extending toward a second side in the depth direction, and along the width direction from respective ends of the pair of flanges on the second side in the depth direction and on both sides in the width direction. a pair of arms extending toward and a fitting joint formed at an end of each of the pair of arms opposite the pair of flanges;
The cross-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 obtained by the following formula A method of manufacturing a hat-shaped steel sheet pile, which satisfies the relationship (i) and includes the step of designing the cross section so that the effective width W is 110 cm or more.
Ae/(W·H)≧0.04 (i)

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