Manufacturing method of hat-shaped steel sheet pile and steel sheet pile wall

Abstract

This improves workability by reducing the horizontal deflection deformation that occurs above ground when hat-shaped steel sheet piles are driven. [Solution] The hat-shaped steel sheet pile comprises, in a cross section perpendicular to the longitudinal direction, a web 2 extending along the width direction, a pair of flanges extending from both ends of the web in the width direction, a pair of arms extending from the respective ends of the pair of flanges on a second side in the depth direction, and fitting joints formed at the ends of each of the pair of arms on the opposite side from the pair of flanges. The second moment of area I of the hat-shaped steel sheet pile in the cross section, the distance d between the line corresponding to the second side surface of the pair of arms in the depth direction in the cross section and the centroid of the hat-shaped steel sheet pile, and the effective width W of the hat-shaped steel sheet pile satisfy the relationship of formula (i), and the effective width W is 115 cm or more, and the second moment of area I is 9500 cm 4 Larger and 40,000 cm 4 is smaller than. d / W≦4.75×10 -5 ×I / d+0.085 (i)

Description

[Technical field]

[0001] The present invention relates to a manufacturing method of a hat-shaped steel sheet pile and a steel sheet pile wall. [Background technology]

[0002] Hat-shaped steel sheet piles are widely used in civil engineering and construction work to build walls for retaining soil and water blocking. Hat-shaped steel sheet piles are penetrated into the ground during driving, so a technique has been proposed to improve workability by reducing the penetration resistance. For example, Patent Document 1 describes a technique for suppressing the earth discharge pressure during driving and improving workability by setting the flange angle, i.e., the angle between the flange and the web and the arm, so that the intersection of the perpendicular lines passing through the center of each flange in the cross section of the hat-shaped steel sheet pile is located outside the cross section of the groove of the hat-shaped steel sheet pile. Patent Document 2 also describes a technique for minimizing the penetration resistance by optimizing the flange angle. Patent Document 3 describes a technique for setting the flange angle based on an economic index and a workability index indicating the penetration resistance at the bottom end of the steel sheet pile. Patent Document 4 describes a technique for setting the cross-sectional shape of a steel sheet pile that is excellent in at least one of the performances of economy and workability, based on the relationship between an economic evaluation index and a workability evaluation index indicating the ratio of the blockage resistance acting on the bottom end of the steel sheet pile during driving to the cross-sectional area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3488230 [Patent Document 2] Patent No. 3488233 [Patent Document 3] Patent No. 5764945 [Patent Document 4] JP 2014-148798 A Summary of the Invention [Problem to be solved by the invention]

[0004] The techniques described in the above Patent Documents 1 to 4 all focus on the behavior of the steel sheet pile in the ground, and aim to improve the workability by reducing the penetration resistance and blockage resistance that act after the steel sheet pile is penetrated into the ground. That is, as a method for evaluating the workability of a steel sheet pile, the optimum steel sheet pile shape has been sought based on the relationship with the ground resistance and soil particle behavior around the steel sheet pile, focusing only on the mechanism when the steel sheet pile is inserted in the ground. However, according to the knowledge obtained by the inventors, in addition to the behavior of the steel sheet pile in the ground, the behavior above ground during driving also affects the workability. In other words, the actual driving of the steel sheet pile proceeds in a manner in which the steel sheet pile is driven into the ground and the state where it protrudes above ground proceed in parallel, and the workability of the steel sheet pile is affected by the coupled behavior of the steel sheet pile in the ground and above ground. Specifically, it was found that when steel sheet piles are cast while being connected widthwise with joints, horizontal deflection deformation occurs in the hat-shaped steel sheet piles, which are cast with the joints restrained to the previously cast steel sheet pile, reducing workability.

[0005] Specifically, if deformation such as twisting or bending occurs in the hat-shaped steel sheet pile, the penetration resistance from the ground from the bottom end of the steel sheet pile or the side of the steel sheet pile during driving, and the fitting resistance with the joint of the steel sheet pile driven before may increase. In addition, if deformation such as bending or twisting occurs in the hat-shaped steel sheet pile above ground, the construction machine such as a vibro hammer may tilt or swing, and the vibration energy of the construction machine, which is originally used to vibrate the hat-shaped steel sheet pile in the vertical direction, may be lost as energy for the horizontal vibration and rotational behavior of the hat-shaped steel sheet pile, resulting in a decrease in the penetration speed of the hat-shaped steel sheet pile into the ground. If the construction machine tilts or swings, a horizontal load is applied to the head of the steel sheet pile, which may increase the deflection and twisting behavior of the steel sheet pile, resulting in a vicious cycle in which the loss of vibration energy increases. Therefore, in order to ensure good workability of steel sheet piles, it is important to suppress not only their behavior in the ground but also the deflection and torsional deformation of the steel sheet piles above ground.

[0006] However, the behavior of the hat-shaped steel sheet pile above ground, which may cause such a decrease in workability, is not described in the above-mentioned Patent Documents 1 to 4. In evaluating the driveability of a steel sheet pile, it has not been done to search for an optimal cross-sectional shape of the steel sheet pile by looking at the overall behavior of the steel sheet pile, including the aboveground part, as well as the behavior in the ground. One reason 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 is not significantly eccentric from the cross-sectional center of gravity of the steel sheet pile, and therefore deformation such as bending and twisting of the steel sheet pile that affects the workability is unlikely to occur in the aboveground part. Therefore, it has been thought that the workability of the steel sheet pile is dominated by resistance from the ground. In fact, if the steel sheet pile is small, the cross-sectional deformation of the steel sheet pile during driving is not significantly exposed in the aboveground part, and the relationship between the deformation behavior in the aboveground part and the workability has not been paid attention to, and there has been no knowledge about the relationship between the two. However, in recent years, the increase in the cross section of hat-shaped steel sheet piles has led to an increase in deformation behavior, such as torsion and deflection, of the hat-shaped steel sheet piles at above-ground sections, which may affect constructability.

[0007] Therefore, the present invention aims to provide a new and improved manufacturing method for hat-shaped steel sheet piles and steel sheet pile walls that can improve workability by reducing the horizontal deflection deformation that occurs at the above-ground part when the hat-shaped steel sheet piles are driven. [Means for solving the problem]

[0008] According to an aspect of the present invention, a hat-shaped steel sheet pile includes, in a cross section perpendicular to the longitudinal direction, a web extending along the width direction on a first side in the depth direction, a pair of flanges extending from both ends of the web in the width direction to both sides in the width direction and toward a second side in the depth direction, a pair of arms extending from each end of the pair of flanges along the width direction and toward both sides in the width direction on the second side in the depth direction, and fitting joints formed at ends of the pair of arms opposite to the pair of flanges. The moment of inertia I (cm) of the hat-shaped steel sheet pile in the cross section is 4), the distance d (cm) between the straight line corresponding to the second side surface of the pair of arms in the depth direction in the cross section and the centroid of the hat-shaped steel sheet pile, and the effective width W (cm) of the hat-shaped steel sheet pile satisfy the relationship of the following formula (i), and the effective width W is 115 cm or more and the area secondary moment I is 9500 cm 4 Larger than 40000cm 4 Less than. d / W≦4.75×10 -5 ×I / d+0.085 (i)

[0009] In the above hat-shaped steel sheet pile, the area second moment I, the distance d, and the effective width W may satisfy the relationships of the following formula (ii) and formula (iii). d / W≦1.90×10 -5 ×I / d+0.111 (ii) I / d≧828 (iii)

[0010] According to another aspect of the present invention, there is provided a method for manufacturing a steel sheet pile wall using the above-mentioned hat-shaped steel sheet pile. The method for manufacturing a steel sheet pile wall may include 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 into a fitting joint of a steel sheet pile driven in advance.

[0011] According to the above-mentioned configuration, the horizontal deflection deformation occurring in the above-ground part when the hat-shaped steel sheet pile is driven can be reduced, thereby improving workability. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view of a hat-shaped steel sheet pile according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining a fitting center in a fitting joint of the hat-shaped steel sheet pile shown in FIG. [Diagram 3] FIG. 13 is a diagram showing the boundary conditions of the hat-shaped steel sheet pile during driving, and conceptually explaining the engagement with the preceding sheet pile and the gripping state of the hat-shaped steel sheet pile by the vibro hammer. [Figure 4]FIG. 13 is a diagram for conceptually explaining the horizontal deflection deformation that occurs in a hat-shaped steel sheet pile during driving. [Diagram 5] 1 is a graph plotting comparative examples and examples of the present invention with the ratio I / d of the area second moment I to the distance d on the horizontal axis and the deflection amount f shown as a ratio to the deflection amount generated in a conventional hat-shaped steel sheet pile on the vertical axis. [Figure 6] 1 is a graph plotting comparative examples and examples of the present invention with the ratio I / d of the area second moment I to the distance d on the horizontal axis and the ratio d / W of the distance d to the effective width W on the vertical axis. [Figure 7] This is a graph in which only the examples in which the deflection amount f is reduced to less than 80% of that of a conventional hat-type steel sheet pile are extracted from the examples shown in the graph of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and duplicated explanations will be omitted.

[0014] Fig. 1 is a cross-sectional view of a hat-shaped steel sheet pile according to an embodiment of the present invention. As shown in Fig. 1, the hat-shaped steel sheet pile 1 includes, in a cross section perpendicular to the longitudinal direction (z direction in the figure), a web 2 extending along the width direction (x direction in the figure) on a first side in the depth direction (the back side in the y direction in the figure), flanges 3A, 3B extending from both ends of the web 2 in the width direction to both sides in the width direction and toward a second side in the depth direction (the front side in the y direction in the figure) and forming a flange angle θ (acute angle side) with the width direction, arms 4A, 4B extending from the respective ends of the flanges 3A, 3B along the width direction and toward both sides in the width direction on the second side in the depth direction, and fitting joints 5A, 5B formed at the ends of the arms 4A, 4B opposite to the flanges 3A, 3B.

[0015] As described later, the moment of inertia I (cm 4) and a straight line L corresponding to the surface of the second side in the depth direction of the arms 4A and 4B in the cross section (the front side in the y direction in the drawing). A The distance d (cm) between the center C of the hat-shaped steel sheet pile 1 and the effective width W (cm) of the hat-shaped steel sheet pile 1 satisfies the following formula (1). A ,E B is equal to the distance between d / W≦4.75×10 -5 ×I / d+0.085 (1)

[0016] Here, the line L A However, even in such a case, in the cross section of the hat-shaped steel sheet pile 1 shown in the design drawing, for example, the second side surfaces in the depth direction of the arms 4A and 4B are on the same straight line, and the straight line L corresponding to these surfaces is A In this case, the direction in which the arms 4A, 4B extend 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, the second side faces in the depth direction of the arms 4A, 4B may not be strictly on the same straight line, for example, at the head end face of the hat-shaped steel sheet pile 1 exposed above ground, due to deformation of the arms 4A, 4B during construction, etc. However, even in this case, the straight line L corresponding to the second side faces in the depth direction of the arms 4A, 4B shown on the same straight line in the design drawing showing the state before driving, for example, may be determined. A In the case where the design drawing is not used, the fitting center E located at each end of the arms 4A and 4B on the head end face of the hat-shaped steel sheet pile 1 exposed on the ground can be specified. A ,E B The straight line connecting the arms 4A and 4B is the design thickness center line L C (See Fig. 2) and the plate thickness center line L C By translating the arms 4A and 4B in the direction of the depth to the second side by half the thickness of the plates, a straight line L A can be identified.

[0017] When the shape of the hat-shaped steel sheet pile 1 shown in Fig. 1 is geometrically valid, the arm length Ba, effective width W, web length Bw, height H and flange angle θ satisfy the relationship W-Bw-2H / tan θ>0. Here, the height H is the height of the cross section of the hat-shaped steel sheet pile 1, including the plate thicknesses of the web 2 and arms 4A, 4B, but not including the overhangs of the fitting joints 5A, 5B.

[0018] Fig. 2 is a diagram for explaining the fitting center of the fitting joint of the hat-shaped steel sheet pile shown in Fig. 1. As shown in the figure, 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 that is driven adjacently. The fitting center E of the fitting joint 5A A is a designed thickness center line L of the arm 4A and the arm 4B, which is located midway between the end position of the arm 4A where the fitting joint 5A is formed and the end position of the arm 4B where the virtual fitting joint 5B is formed, when the arm 4B and the fitting joint 5B are virtually arranged. C The center of engagement E of the engagement joint 5B located on the opposite side of the hat-shaped steel sheet pile 1 can be defined as the point on the B can be defined in the same way. As mentioned above, the fitting center E A ,E B is related to the effective width W of the hat-shaped steel sheet pile 1.

[0019] 3 and 4 are diagrams for conceptually explaining the horizontal deflection deformation that occurs in a hat-shaped steel sheet pile during driving. Fig. 3 is a plan view of a hat-shaped steel sheet pile 1 showing a boundary state that causes horizontal deflection deformation in the hat-shaped steel sheet pile, and Fig. 4 is a side view of the hat-shaped steel sheet pile 1. As shown in Figs. 3 and 4, the hat-shaped steel sheet pile 1 is driven by a vertical vibration load B applied from a vibro hammer 6 that clamps flanges 3A and 3B at the upper end. In order to stably support the hat-shaped steel sheet pile 1, the vibro hammer 6 is placed so that its position in the depth direction (y direction in the figure) approximately coincides with the centroid C of the cross section.

[0020] Here, a hat-shaped steel sheet pile 1P is installed near the ground surface, and the hat-shaped steel sheet pile 1 is installed while fitting the fitting joint 5A to the fitting joint 5B of the hat-shaped steel sheet pile 1P. 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 located at the fitting center E of the fitting joint 5B. A The horizontal displacement is restrained by contacting the vibro hammer 6 at multiple points near the ground. Therefore, the hat-shaped steel sheet pile 1 is restrained by the fitting joint and the ground at the lower part in the longitudinal direction protruding above ground. On the other hand, the centroid C, which is the point of application of the vibration load by the vibro hammer 6, is located at a distance d in the depth direction, i.e., in the weak axis direction of the cross section of the hat-shaped steel sheet pile 1, from the fitting joint part where the horizontal displacement is restrained. Therefore, according to this distance d, as shown in Fig. 4, a bending moment M due to the vibration load B acts on the part of the hat-shaped steel sheet pile 1 above the upper end of the hat-shaped steel sheet pile 1P. As a result, a deflection f in the depth direction (y direction in the figure) occurs in the hat-shaped steel sheet pile 1. If the deflection f becomes large, a part of the vertical vibration load B by the vibro hammer 6 is converted into horizontal vibration, and the vibration load in the casting direction is not effectively transmitted to the ground, resulting in energy loss and reduced workability.

[0021] According to the experience of the inventors, when a conventional hat-shaped steel sheet pile of 16 m in length was driven with a vibro hammer suspended from a crawler crane under a vibration load of 33 kN and a maximum amplitude of 6 mm in the vertical direction, when the hat-shaped steel sheet pile engaged with the adjacent hat-shaped steel sheet pile at a total of 6 m (5 m underground and 1 m above ground), the vibration in the depth direction of the remaining 10 m above the upper end of the adjacent hat-shaped steel sheet pile increased and reached a maximum amplitude of 6 mm. As a result, the vibro hammer swung and the vibration load was no longer effective, and the driving speed of the hat-shaped steel sheet pile decreased.

[0022] In this embodiment, in order to prevent deterioration of workability, the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the deflection amount f compared to the conventional hat-shaped steel sheet pile was examined as a cantilever model in which the hat-shaped steel sheet pile protruding above ground is a fixed end whose lower end is restrained by the fitting joint part with the preceding sheet pile and the ground, and the upper end is a free end that receives a bending moment due to a vibration load. The inventors focused on the following points in the examination. First, in order to reduce the horizontal deflection amount f against the bending moment M as shown in FIG. 4, it is advantageous to reduce the bending moment M and to increase the second moment of area I of the hat-shaped steel sheet pile 1, which is an index of resistance to the bending moment M. Here, since the bending moment M is proportional to the distance between the joint fitting position and the cross-sectional centroid which is the position where the steel sheet pile is gripped by the construction machine, the centroid distance d shown in FIG. 3 can be used as an index representing the bending moment M. In order to reduce the bending moment M, it is advantageous to reduce the centroid distance d. I / d, which combines the centroid distance d, which is an index of bending moment M, and the second moment of area I, is an index that indicates that the deflection amount f is reduced as the value increases.

[0023] On the other hand, we aimed not only to make a steel sheet pile that can reduce the amount of deflection but also to make the cross section economical, so we aimed to make the cross section larger and incorporated the effective width W as an indicator. By making the width wider, the web width can be increased and the area ratio of the flange portion to the specified width can be reduced, so that the geometric moment of inertia per specified width, i.e., bending rigidity, can be secured with a smaller cross-sectional area. In other words, a large geometric moment of inertia I can be obtained with an economical cross section. In other words, when the effective width W is large, even if the geometric moment of inertia per wall width is the same, the geometric moment of inertia I of a single hat-shaped steel sheet pile 1 (per piece) becomes larger, and the range of bending moment M that can keep the amount of deflection f within an allowable range can be increased.

[0024] Here, since the bending moment M and the centroid distance d are proportional to each other, increasing the centroid distance d increases the bending moment M, but in this case, if the effective width W is also increased, the deflection f can be kept within an allowable range by increasing the area second moment I. In other words, by keeping d / W below a specified value, the deflection f can be kept within an allowable range.

[0025] Therefore, the following study is intended to specify the conditions of the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the deflection amount f, focusing on the values ​​of I / d and d / W.

[0026] The results of the study are shown in Tables 1 to 4. The study was carried out on the moment of inertia I per 1m of wall width of a wall in which hat-shaped steel sheet piles 1 are connected in the width direction. W is 10000cm 4 / m level, 25000cm 4 / m level, 45000cm 4 / m level, and 50000cm 4 The tests were carried out for each of the cases of 0.1 mm to 1.2 mm, and examples in which the deflection f was reduced compared to the conventional hat-shaped steel sheet piles shown as Comparative Examples 1 to 4 are shown as Examples 1 to 32. 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.

[0027] [Table 1]

[0028] [Table 2]

[0029] [Table 3]

[0030] [Table 4]

[0031] FIG. 5 shows the results of the comparisons 1 to 4 and examples 1 to 32 in terms of the moment of inertia I (cm 4 The graph is a plot of the ratio I / d of the moment of inertia (in mm) to the distance d (cm) on the horizontal axis and the amount of deflection f (comparison with the conventional method) on the vertical axis. W The levels are divided into groups of points E1-E7, points E8-E16, points E17-E29, and points E30-E32. As shown in the graph in Figure 5, the value of I / d is the moment of inertia I W Although it differed for each level, within each level, there was a tendency for the deflection amount f to decrease as the I / d value increased.

[0032] FIG. 6 shows the results of the comparisons 1 to 4 and examples 1 to 32 in terms of the moment of inertia I (cm 4 6 is a graph plotting the ratio I / d of the distance d (cm) to the effective width W (cm) on the horizontal axis and the ratio d / W of the distance d (cm) to the effective width W (cm) on the vertical axis. -5 ×I / d+0.085. In contrast, points P1 to P4, which are comparative examples, are in the range of d / W>4.75×10 -5 ×I / d+0.085. Therefore, from the results of the above study, the following formula (1) can be specified as the condition for the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the deflection amount f. d / W≦4.75×10 -5 ×I / d+0.085 (1)

[0033] Here, since the area moment of inertia I increases in proportion to the square of the distance d, the larger the area moment of inertia I, the larger the d / W. Also, since the rate of increase of the area moment of inertia I is greater than the rate of increase of the distance d, the larger the area moment of inertia I, the larger the I / d. In other words, I / d tends to increase with an increase in d / W. Therefore, in the hat-shaped steel sheet pile, I / d and d / W are correlated indexes, and for example, in Comparative Examples 1 to 4 (points P1 to P4) in FIG. 6, they are almost proportional. In the case of the hat-shaped steel sheet pile, when the width is increased to obtain an economical cross section and the value of d is increased to secure a large area moment of inertia, there was no standard for how to appropriately determine the effective width W and the distance d, respectively, in order to keep the deflection within an allowable range. In the above study, it was found that, from the viewpoint of reducing the deflection amount f, it is effective to set d / W to a value equal to or less than a predetermined value determined according to I / d. As a result, the relationship between I / d and d / W in equation (1) was defined as the condition for keeping the deflection amount below that which occurs in conventional steel sheet piles, and a criterion was provided for determining the effective width W and distance d according to the second moment of area I.

[0034] In addition, in the above-mentioned Examples 1 to 32, the moment of inertia I per 1 m of wall width of the wall bodies connected in the width direction is W is 10000cm 4 / m level, 25000cm 4 / m level, 45000cm 4 / m level, and 50000cm 4 The hat-shaped steel sheet piles 1 are included at the / m level, and the moment of inertia I of each of these hat-shaped steel sheet piles 1 is 9500 cm 4 Larger and 80,000 cm 4 in the range smaller than (9500 cm 4 <I<80000cm 4 ).

[0035] Furthermore, for the hat-shaped steel sheet pile with an expanded width, i.e., a so-called thin-walled, large cross section, it is preferable to make the cross section more compact when considering manufacturability. From this viewpoint, among the examples considered above, the hat-shaped steel sheet pile 1 with a moment of inertia I of 9500 cm 4 Larger than 40000cm 4 in the range smaller than (9500 cm 4 <I<40000cm 4 ) is more preferable.

[0036] Fig. 7 is a graph in which only examples in which the deflection amount f (comparison with the conventional example) is less than 0.8, that is, the deflection amount f is reduced to less than 80% of that of the conventional hat-shaped steel sheet pile, are extracted from Examples 1 to 32 shown in the graph of Fig. 6. Specifically, Examples 1 to 7, Examples 9 to 16, and Examples 22 to 32 are extracted. In the graph of Fig. 7, points E1 to E7, E9 to E16, and E22 to E32 showing the extracted examples are within the range of d / W≦1.90×10 -5 ×I / d+0.111 and I / d≧828. In contrast, points P1 to P4, which are comparative examples, are in the range of d / W>1.90×10 -5 ×I / d+0.111. Therefore, the following formula (2) and formula (3) can be specified as the conditions for the cross-sectional shape of the hat-shaped steel sheet pile 1 that can reduce the deflection f to a level at which a significant effect is observed in practice, specifically, to less than 80% of that of the conventional hat-shaped steel sheet pile. d / W≦1.90×10 -5 ×I / d+0.111 (2) I / d≧828 (3)

[0037] In addition, the above study was carried out in the study of expanding the effective width W of the hat-shaped steel sheet pile 1 beyond 90 cm, which is the effective width of the conventional hat-shaped steel sheet pile, in order to construct a cross section that is more efficient and economical than the conventional hat-shaped steel sheet pile, so the effective width W is 100 cm or more in Examples 1 to 32. However, under the conditions of the above formulas (1) to (3), the cross section that reduces the amount of deflection more than the conventional hat-shaped steel sheet pile is defined only as the relationship between the ratio d / W of the effective width W to the distance d and the ratio I / d of the distance d to the area second moment I, so it is considered that it can be applied, for example, even when the effective width W is less than 100 cm as a cross-sectional shape that can ensure a cross section more economical than the conventional hat-shaped steel sheet pile.

[0038] On the other hand, from the viewpoint of economical construction, it is desirable to be able to reuse existing construction machines even if the effective width of the hat-shaped steel sheet pile is enlarged. As a type of construction machine, a press-in machine that can handle an effective width of 90 cm (Comparative Examples 1 to 4) is widely used, and as a press-in machine that can be applied to sizes with an effective width of more than 90 cm, there are press-in machines that can handle an effective width of 115 cm to 146.1 cm. In other words, from the above viewpoint, it is preferable that the effective width W of the hat-shaped steel sheet pile is 115 cm or more.

[0039] According to the embodiment of the present invention described above, a hat-shaped steel sheet pile having a cross-sectional shape that effectively reduces horizontal deflection deformation occurring during driving is provided. Such a hat-shaped steel sheet pile is particularly advantageous in a manufacturing method for a steel sheet pile wall including a process of driving a hat-shaped steel sheet pile into the ground while fitting only one of a pair of fitting joints of the hat-shaped steel sheet pile into the fitting joint of a steel sheet pile previously driven. In such a manufacturing method for a steel sheet pile wall, a moment that causes deflection deformation is likely to occur in the hat-shaped steel sheet pile because the position where the construction machine supports the steel sheet pile and applies a vertical vibration load is eccentric to the position where one joint of the hat-shaped steel sheet pile fits into the joint of the steel sheet pile previously driven. However, by applying the embodiment of the present invention, the deflection deformation can be effectively suppressed.

[0040] By suppressing the deflection deformation of the hat-shaped steel sheet pile, the lateral vibration of the hat-shaped steel sheet pile at the aboveground part is reduced, and the driving energy from the construction machine is transmitted to the hat-shaped steel sheet pile with little loss and efficient use of the construction machine's capacity, allowing the penetration speed of the hat-shaped steel sheet pile into the ground to be kept high, and economical construction with good fuel efficiency of the construction machine is possible. In addition, by suppressing the deflection 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 associated with construction can be reduced. If the construction machine becomes larger due to the large cross-section of the hat-shaped steel sheet pile, noise and vibration may also increase, but by suppressing the deflection deformation of the hat-shaped steel sheet pile, construction with suppressed noise and vibration is possible.

[0041] In addition, by suppressing the flexural deformation of the hat-shaped steel sheet pile, the fitting resistance with the joint of the previously cast steel sheet pile can be reduced, thereby reducing the resistance of the entire hat-shaped steel sheet pile when being cast and preventing scraping and welding at the contact surface of the joint.

[0042] Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0043] 1...Hat-shaped steel sheet pile, 2...Web, 3A, 3B...Flange, 4A, 4B...Arm, 5A, 5B...Fitting joint, 6...Vibro hammer, C...Centroid, E A ,E B ...Mating center.

Claims

1. A hat-shaped steel sheet pile, In a cross section perpendicular to the longitudinal direction, the panel comprises a web extending along the width direction on a first side in the depth direction, a pair of flanges extending from both ends of the web in the width direction to both sides in the width direction and toward a second side in the depth direction, a pair of arms extending from each end of the pair of flanges along the width direction and toward both sides in the width direction on the second side in the depth direction, and fitting joints formed at the ends of each of the pair of arms opposite to the pair of flanges, The moment of inertia of the hat-shaped steel sheet pile at the cross section I (cm ４ ), a distance d (cm) between a straight line corresponding to a surface of the second side of the pair of arms in the depth direction in the cross section and the centroid of the hat-shaped steel sheet pile, and an effective width W (cm) of the hat-shaped steel sheet pile satisfy the relationship of the following formula (i), the effective width W is 115 cm or more, and the area secondary moment I is 9500 cm ４ Larger and 40,000 cm ４ A hat-shaped steel sheet pile that is smaller than the above. d / W≦4.75×10 －５ ×I / d+0.085 ・・・(i)

2. The hat-shaped steel sheet pile according to claim 1 , wherein the area second moment I, the distance d, and the effective width W satisfy the relationships of the following formulas (ii) and (iii). d / W≦1.90×10 －５ ×I / d+0.111 ・・・(ii) I / d≧828...(iii)

3. A manufacturing method of a steel sheet pile wall using the hat-shaped steel sheet pile according to claim 1 or 2, A manufacturing method for a steel sheet pile wall, comprising: a step of driving the hat-shaped steel sheet pile into the ground while engaging only one of the fitting joints of the hat-shaped steel sheet pile with a fitting joint of a steel sheet pile driven in advance.

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