JPH0346608B2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to square steel pipe sheet piles used for structures such as earth retaining, foundations, underground walls, wells, and cells in the fields of civil engineering, architecture, marine structures, etc. This invention relates to square steel pipe sheet piles that are particularly suitable for applications that require large size and high yield strength.

(Prior art) As is well known, various types of sheet piles are used in the fields of civil engineering, architecture, marine structures, etc. Among them, steel pipe sheet piles are increasingly used because of their high rigidity and ease of construction. Ta. However, since round steel pipe sheet piles tend to have structural weaknesses at joints and are unsuitable for constructing compact continuous underground walls, square steel pipe sheet piles have come to be used instead. .

The square steel pipe sheet pile 1 shown in the schematic perspective view of FIG. 11 was developed as a reinforcing material for continuous underground walls and concrete walls, and has flange steel plates 2a and 2b parallel to each other, and a web steel plate 4a having notched holes 3, 4b constitutes a box-shaped unit square steel pipe sheet pile 1, and is connected by pipe-shaped joints 5a to 5d provided at both ends of flange steel plates 2a and 2b, as disclosed in Japanese Patent Application Laid-Open No. 57-151725.
As disclosed in the publication, it has good workability and is used for underground walls of permanent structures.

Next, the square steel pipe sheet pile 6 shown in the schematic plan view of FIG.
was developed for reinforcing bars in continuous underground walls.
Female joints 7a, 7b and male joints 8 at both ends, respectively.
The flange steel plates 9a and 9b having a and 8b are parallel to each other, and joint reinforcing bars 10a, 10b, 10
A box-shaped unit steel sheet pile 6 is formed by welding the web steel plates 11a and 11b with the flange steel plates 9a and 9b.
As disclosed in Publication No. 68921, it is used in the construction of continuous underground walls as it has the functions of interlocking pipes, waterstops, and joints.

(Problem to be solved by the invention) In recent years, all structures in the fields of civil engineering, architecture, and marine structures have become larger, and steel sheet piles have become more difficult to withstand large loads and also to withstand large forces acting in the horizontal direction. There is now a need for functionality that can adequately counter these challenges.
Therefore, in order to improve these functions, it is necessary to increase the thickness of the steel sheet pile and increase the cross-sectional area.
When the plate thickness is increased, the price increases, the weight increases, and the workability deteriorates, and when the plate is made thin and has a large cross-sectional area, there are problems in that buckling is likely to occur.

An object of the present invention is to provide a square steel pipe sheet pile that has high rigidity, can withstand large loads, can be manufactured economically, and has excellent workability.

(Means for Solving the Problems) In order to achieve the object, the square steel pipe sheet pile of the present invention has a square steel pipe body made by abutting and joining together the lips of a lip channel steel formed by press-forming a steel plate. , a joint in which the wall body on which the joint part of the square steel pipe body is located is a flange, and the base end of the arm part is welded to each or either one of both end corners of the square steel pipe body along the extension direction of the flange. It is characterized by consisting of.

(Function) Since the present invention manufactures the square steel pipe body by abutting and joining the lips of lip channel steel,
High rigidity and large section modulus. It also has extremely high yield strength even with a thin wall, making it easy and economical to manufacture. Furthermore, the wall where the joint of the lip is located is used as a flange, and the base end of the joint arm is welded to both end corners of the square steel pipe body along the direction of extension of the flange. It has a large ability to withstand tensile force and compressive force acting in the direction opposite to the direction of extension, and the lip joint increases the rigidity of the flange wall, so it can withstand bending and vertical loads that act on square steel pipe sheet piles. It is possible to provide a large resistance force against buckling caused by vertical compressive force.

(Example) FIG. 1 is a schematic plan view of a square steel pipe sheet pile 12 according to the present invention.
14b, each lip 15a, 15b and 16
a and 16b are brought into contact with each other and welded 17a and 17b to form an integral body.

Next, both end corners 18a to 18 of the square steel pipe main body 13
d, male and female identical meshing fitting joints 19a to 19;
Arm portions 20a to 2 of d (hereinafter simply referred to as joints)
The sheet pile is constructed by welding the base ends 21a to 21d of the square steel pipe body 13, but it is recommended that the corners 18a to 18d have a radius of curvature of 1.0 to 5.0 times the thickness t of the square steel pipe body 13 in order to improve welding efficiency and strength. The present inventors have confirmed through research that this is the most preferable method in view of the above problems.

The joints 19a to 19d are half-cut bodies of straight steel sheet piles, and are excellent in terms of water-stopping properties, workability, and rigidity. Therefore, by sequentially driving and connecting the square steel pipe sheet piles 12, it is possible to create a durable continuous underground structure. It is possible to build walls.

Component parts 22a and 22 in which the lips 15a and 16a, 15b and 16b are brought into contact and welded together
b (hereinafter referred to as a joint in the present invention) has high rigidity;
As shown in Fig. 2, a force 23 acting in the vertical direction acts on the square steel pipe plate 12 due to bending, vertical loads, etc.
Demonstrates high yield strength against X and 23Y.

In the present invention, the walls on which the joints 22a and 22b are located are called flanges 24a and 24b, respectively, and the joints 19a to 19d are called flanges 24a and 24b, respectively.
Arm portion base ends 21a to 21d are attached to both end corner portions 18a to 18d of the square steel pipe main body 13 along the extension direction of the square steel tube body 4b.
It is said that they are welded together through the

Next, the bent steel pipe sheet pile 2 shown in the schematic plan view of Fig. 3
5 is a joint 19e welded to the flange 24a,
Arm parts 20e, 20f of 19f and flange 24
Arm part 2 of joints 19g and 19h welded to b
This example has different lengths, 0g and 20h, and is suitable for constructing curved wells and quays.

FIG. 4 shows an example in which different joints are provided on the square steel pipe body 13, and seamless steel pipes 26a, 26
Fitting portions 28a, 28b formed by vertically arranging slits 27a, 27b in b, and an arm portion 29 formed of a flat steel plate.
Female joints 30a and 30b formed by welding a and 29b
and round steel bars 31a, 31b on the other side.
A male joint 3 formed by welding fitting parts 32a, 32b made of
Since the square steel pipe sheet pile 35 equipped with 4a and 34b has very high physical strength as a joint, it is suitable for constructing a large square steel pipe sheet pile in which the diameter of the square steel pipe body 13 exceeds 800 to 1000 mm. Are suitable.

Next, the square steel pipe sheet pile 36 shown in FIG.
0a and 30b are the same as the example shown in FIG. 4, but the male joint has a fitting part 38a and
38b and arm portions 39a and 39b made of flat steel plates.
It has male joints 40a and 40b welded together.

It is possible to completely watertight the joint by pouring concrete using the steel pipes 37a and 37b of the male joints 40a and 40b, so it is particularly suitable for constructing continuous underground walls that require watertightness. There is.

The square steel pipe sheet pile 41 shown in FIG. 6 has a flange 24b.
It has a structure that does not have a joint on the side, and the joint 19a,
19c and joints 22a, 22b, etc., are exactly the same as those of the square steel pipe sheet pile 12 in FIG.
Used for constructing arch-shaped continuous walls and simple underground walls.

The square steel pipe sheet pile 42 in Fig. 7 is a lip groove type steel 14.
Lips 15a, 15b, 16a, 1 of a, 14b
This is an example in which groove type steels 43a, 43b are interposed instead of directly abutting flange 4 of groove type steel 43a.
4a to the lip 15a and the flange 44b to the lip 16a, the flange 44c of the channel steel 43b to the lip 15b, and the flange 44d to the lip 16b, and weld them together 45a.
45d to construct a square steel pipe main body 46, and then joints 19a to 19d are welded to the square steel pipe main body 46 in the same manner as the square steel pipe sheet pile 12 shown in FIG. Abutment joints of standard lips are also encompassed by the present invention. Therefore, the square steel pipe sheet piles 42 are suitable for economical construction of long continuous walls.

Next, the square steel pipe sheet pile 47 shown in FIG. 8 is an embodiment in which joints 19a and 19d are diagonally welded to one of the corners of both ends of the square steel pipe body 13, and is used for the same purpose as the well-known Z-type steel sheet pile. do. In the present invention, as described above, the joint is welded to each of the corners of both ends of the square steel pipe body 13 as shown in FIG. 1, and also to one of the corners of both ends as shown in FIGS. 6 and 8. By doing so, it is possible to respond accurately even when requirements differ depending on the location, such as continuous underground walls or wells.

The graph in Fig. 9 shows the shape of the square steel pipe sheet pile 12 shown in Fig. 1 when the same type of joints are welded to the square steel pipe body with a lip and the one without a lip, respectively, with a square cross section of Dmm on one side. This is a graph showing the difference in section modulus, with the horizontal axis representing the length of one side Dmm and the vertical axis representing the section modulus Zcm ³ /Kg per sheet pile weight. As is clear from the figure, the difference between the curve 48 showing the section modulus of a square steel pipe sheet pile with a lip and the curve 49 showing the section modulus of a square steel pipe sheet pile without a lip is extremely large. The plate thickness t of the square steel pipe body for comparison was 12 mm.

In addition, in research by the present inventors, the lip length d
(illustrated in FIG. 1) and the ratio D/d of the above D is:
It is desirable to design for more than 3 and less than 12.
If D/d is less than 3, it is difficult and uneconomical to manufacture, and 12
If this is the case, the effect in terms of cross-sectional performance will be reduced and it will be difficult to achieve the objective.

The square steel pipe sheet piles according to the present invention are shown in Figures 10a to 10j.
It is possible to adopt well-known joints such as those shown in Figure 1, and use them as appropriate depending on the application, but according to the knowledge of the present inventors, the first joint is the best in terms of economy, structural reliability, and workability. Male and female meshing fitting joints 19a to 19h as shown in FIGS. 3 and 3 and female joints 30a and 30 shown in FIGS.
b. Joints such as male joints 34a, 34b, 40a, and 40b were the best.

(Effects of the Invention) The square steel pipe sheet piles of the present invention can be made into a variety of sizes, and in particular can be made with thin walls and large diameter cross-sections that have never been seen before, so the economic efficiency is extremely high. It is. Furthermore, it is easy to manufacture, has good workability, and has high structural rigidity and water-stopping properties, making it highly effective in practical applications.

[Brief explanation of drawings]

Fig. 1 is a schematic plan view showing an example of a square steel pipe sheet pile according to the present invention, Fig. 2 is a schematic perspective view of the square steel pipe sheet pile for explaining buckling strength, and Fig. 3 shows different arm lengths of the joint. Schematic plan view of square steel pipe sheet piles, No. 4
The figure is a schematic plan view showing an example of a square steel pipe sheet pile having a joint using steel pipes and round steel bars according to the present invention.
The figure is a schematic plan view showing an example of a square steel pipe sheet pile using steel pipes as male and female joints. Figure 9 is a graph comparing the section modulus per square steel pipe sheet pile weight, Figures 10 a to j are schematic explanatory views of joints, Figure 11 is a schematic perspective view of a known square steel pipe sheet pile,
FIG. 12 is a schematic plan view of a known square steel pipe sheet pile. 1... Square steel pipe sheet pile, 2a, 2b... Flange steel plate, 3... Notch hole, 4a, 4b... Web steel plate,
5a-5d...pipe type joint, 6...square steel pipe sheet pile, 7a, 7b...female joint, 8a, 8b...male joint, 9a, 9b...flange steel plate, 10a-10
d...Reinforcing bar for joint, 11a, 11b...Web steel plate, 12...Square steel pipe sheet pile, 13...Square steel pipe body, 14a, 14b...Rip channel steel, 15
a, 15b, 16a, 16b...lip, 17
a, 17b...Welding, 18a-18d...Corners,
19a to 19h...Joint, 20a to 20h...Arm portion, 21a to 21d...Base end, 22a, 22
b...Joint part, 23X, 23Y...Action force, 24
a, 24b...flange, 25...square steel pipe sheet pile,
26a, 26b...Seamless steel pipe, 27a, 2
7b...slit, 28a, 28b...fitting part,
29a, 29b...arm part, 30a, 30b...
...Female joint, 31a, 31b...Round bar steel, 32a,
32b... Fitting part, 33a, 33b... Arm part, 34a, 34b... Male joint, 35, 36...
Square steel pipe sheet piles, 37a, 37b...Steel pipes, 38a,
38b... Fitting part, 39a, 39b... Arm part, 40a, 40b... Male joint, 41, 42...
Square steel pipe sheet piles, 43a, 43b...channel steel, 44a
~44d...Flange, 45a~45d...Welding, 46...Square steel pipe body, 47...Square steel pipe body,
48, 49...Curve.

Claims (1)

[Claims] 1. A square steel pipe body formed by abutting and joining the lips of a lip channel steel formed by press-forming a steel plate, and a wall body in which the joint portion of the square steel pipe body is located, as a flange, and in the extending direction of the flange. A square steel pipe sheet pile comprising a joint in which a base end of an arm part is welded to each or one of both end corners of the square steel pipe main body along the main body.