JPH0377323B2 - - Google Patents

Description

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

(Prior Art) As is well known, in the construction of pier foundations, rock walls, artificial islands, etc., cells 1 and 2 as shown in FIGS. 10 and 11 are often constructed. Cell 1 is a combination of a straight steel sheet pile 3 and a straight steel sheet pile 5 to which a reinforcing material 4 made of T-shaped steel is welded. Steel pipe sheet pile 8 with welded joints 7a and 7b
It is constructed by connecting these alternately. These cells 1 and 2 can be constructed by driving unit steel sheet piles into the ground one after another and connecting them together, or by making cells of the planned dimensions in advance, integrating them with reinforcing rings, hoisting them with a crane, etc., and using a vibrohammer at the planned location. Methods such as pouring are used.

In addition, as shown in Figure 12, the diameter is 5 to 10 m.
A cell 9 made of a welded structural steel pipe body is also adopted.

As shown in the schematic plan views of FIGS. 13a to 13d, the straight steel pipe sheet pile 5 used in the cell 1 has the following structure.
Scalene angle steel 10a, 1 is placed on the back side of the straight steel sheet pile 3.
A steel sheet pile 11 formed by welding 0b in a gassho shape, a T-shaped steel 12 and angle steel 13a, 1 on the back of a straight steel sheet pile 3.
3b, a steel sheet pile 17 made by welding a channel steel 15 and angle steel 16a, 16b to the back of the straight steel sheet pile 3, and a similar rip channel steel 18 and angle steel 19a to the back of the straight steel sheet pile 3. , 19b are welded together.

Further, as shown in the schematic explanatory diagram of FIG. 14, the steel pipe sheet pile 8 used in the cell 2 has joints 7a and 7 formed of half-cut straight steel sheet piles at both ends of the round steel pipe 6.
Similar steel pipe sheet piles 8a may be successively connected to form a cell, and the steel pipe sheet pile 8 is a prefabricated steel pipe sheet pile cell published by the Prefabricated Steel Sheet Pile Cell Method Study Group in March 1981. This is disclosed on page 26 of the construction method research report.

Furthermore, as shown in Fig. 15, as shown in Fig. 15, rectangular steel bars 21a, 21b and steel pipes 22a, 22b with slits are welded to both ends of the square steel pipe sheet piles used for continuous underground walls, etc., as shown in JP-A-55-68921. A square steel pipe sheet pile 25 has been proposed in which flange steel plates 23a and 23b are welded together with web steel plates 24a and 24b.

(Problems to be Solved by the Invention) Since the steel sheet piles 11, 14, 17, and 20 are all made of rolled steel, there are restrictions on dimensions due to various rolling conditions, and the application is limited to small cells. However, there is a problem that the welding cost increases significantly due to the large number of welded parts, and it also has the disadvantage that it cannot be used on hard ground or in deep water areas.

In addition, the steel pipe sheet pile 8 can be driven into deep ground and has high overall rigidity, making it possible to construct large cells, but it is prone to excessive deformation when hoop tension is applied. There is a problem in that filling is required.

Furthermore, the square steel pipe sheet pile 25 has a flange steel plate 2
3a, 23b and the web steel plates 24a, 24b, which increases welding costs, and the welded portions tend to become structural weaknesses.

Furthermore, although the cell 9 has the advantage of being economically manufacturable, it has the problem of being difficult to install in places where the ground is sloping.

The objects of the present invention are to be easy to manufacture, have a large degree of freedom in design, have no structural weaknesses, have sufficient resistance to large earth pressure and water pressure, be easy to construct, and be economical. The purpose of the present invention is to provide a square steel pipe sheet pile that can be manufactured in a number of ways, and another purpose is to provide a square steel pipe sheet pile that is particularly suitable for constructing large cells, wells, etc.

(Means for Solving the Problems) In order to achieve the object, the square steel pipe sheet pile of the present invention consists of a square steel pipe body and a fitting joint welded to both end corners of one flange side of the square steel pipe body. It is characterized by becoming.

(Function) Since the main body of the steel pipe sheet pile of the present invention is a square steel pipe, it is easy to manufacture in terms of production technology, and the degree of freedom in manufacturing dimensions is extremely high, so it meets the needs for the most economical design in the fields of civil engineering, architecture, marine structures, etc. It is possible to respond to

In addition, since the square steel pipe sheet pile of the present invention has fitting joints welded to the corners of both ends on one flange side of the square steel pipe body, it has a high resistance value against tensile force in the extension direction of the flange, and also has a high resistance value to the tensile force in the extension direction of the flange. The steel pipe body has high structural reliability against horizontal and vertical forces.

Furthermore, since the square steel pipe main body has high rigidity and good straightness during pouring, it is possible to accurately construct a structure at a desired position.

In addition, since the fitting joint extends in the direction of extension of one flange side of the square steel pipe body, when constructing a large cell or continuous underground wall, it is smooth and free of protrusions and has no structural weaknesses. It is possible to form a surface wall surface.

Since the inside of the square steel pipe body is completely hollow, quick and economical construction is possible by employing the press-in method.

In addition, since only one pair of fitting joints is required, there are fewer welding points and manufacturing costs are reduced.

In addition, since the arms of the joint are welded to the corners of the square steel pipe body, welding is extremely easy, fewer jigs and tools are required for welding, and inspection for welding defects is simple, so welding costs are extremely low.

In addition, the square steel pipe body is under biaxial stress in the vertical direction and the hoop direction, so it can exhibit sufficient strength, and has strong resistance not only to hoop tension but also to bending from a direction perpendicular to the axial direction. Therefore, unlike round steel pipe sheet piles, there is little need for filling concrete, making it extremely advantageous economically. Since the square steel pipe sheet pile according to the present invention has high rigidity, it can be erected on hard ground, which was difficult to accommodate with conventional steel sheet piles.

Furthermore, there are no structural problems with production technology, so
Dimensions, plate thickness, and materials can be changed according to demand, and fitting joints can be selected with any shape and strength, so there is an extremely large degree of freedom in design.

(Example) Fig. 1 is a plan view of a square steel pipe sheet pile 26 according to the present invention, in which both end corners 29a of a flange 28a on one side of the flanges 28a, 28b of a square steel pipe main body 27,
Fitting joints 30a and 30b are attached to flange 29b.
It is welded along the extending direction of 8a.

FIG. 2 is a plan view of another square steel pipe sheet pile 31 according to the present invention.
Fitting joints 35 are provided at both end corners 34a and 34b of a.
a and 35b are welded along the extending direction of the flange 33a.

In this way, the fitting joints 30a, 30b and 35a, 35b are welded along the extending direction of the flanges 28a and 33a so that their axes coincide with each other. It is said that it will exist.

The fitting joints 30a, 30b, 35a,
If 35b are made of the same type of interlocking fitting joint, it is economically extremely advantageous because there are fewer types of parts, and the fitability and watertightness are good, and in addition, the strength as a joint is extremely high.

Fitting joints 30a, 30b and 35a, 35b
It is extremely advantageous in terms of manufacturing costs to use semi-cut straight steel sheet piles.

Now, the square steel pipe sheet piles 26 and 31 have the above-mentioned effects due to their structural characteristics, and are easy to manufacture, have high strength, and have extremely good workability. 400mm or more 800×
It can be applied to large cross-sections of about 800 mm, but if larger dimensions and greater strength are required, the third method is applicable.
Square steel pipe sheet piles 36 and 37 as shown in FIG. 4 are suitable. The square steel pipe sheet pile 36 has corner portions 4 at both ends of one flange 39 of a square steel pipe main body 38 having a square cross section.
Of the corners 0a and 40b, a male joint 43 made by welding an arm 42 made of a flat steel plate to a round steel bar 41 is attached to the corner 40a, and a slit 45 is attached to the steel pipe 44 at the corner 40b.
An arm 46 made of a flat steel plate is welded to a female joint 47. In addition, the square steel pipe sheet pile 37 has a joint 52 formed by welding an arm 51 made of a flat steel plate to a small diameter steel pipe 50 to each of the corner portions 49a and 49b at both ends of the square steel pipe main body 48, and a large diameter steel pipe 54 having a slit 53 and a flat steel plate. A female joint 56 formed by welding an arm 55 consisting of a flange 57 extends in the direction in which the flange 57 extends.

When seamless steel pipes are used for the steel pipes 44 and large-diameter steel pipes 54, due to their high physical strength, it is possible to obtain joints with high strength that cannot be seen in conventional joints. ~
It is possible to economically manufacture square steel pipe sheet piles with square steel pipe bodies of 1500 x 1500 mm or more.

Further, as the square steel pipe body in the present invention, a square steel pipe obtained by roll forming an electric resistance welded steel pipe, or a square steel pipe formed by press bending or roll forming a flat steel plate into a square steel pipe shape, and then welding may be used as appropriate. . When ERW steel pipes are used as the material for square steel pipes, there are many economic advantages, especially when manufacturing long square steel pipe sheet piles, since there is a large degree of freedom in the length of the pipes in addition to the plate thickness and diameter.

Next, regarding the ease of welding of the fitted joint in the present invention and its excellent physical strength, the fifth point is as follows.
This will be explained according to the diagram.

FIG. 5 is a partially enlarged view of the corner of the square steel pipe sheet pile 26 shown in FIG. 1, and a fitting joint 30b is welded to the corner 29b along the axis XX of the flange 28a. Further, 58 indicates a welded metal.

In the present invention, since welding can be performed from the outside of the square steel pipe body 27, there are no particular restrictions on the welding method, and a simple support is required to maintain the welding posture of the square steel pipe body 27 and the fitting joint 30b, so welding costs are reduced. This has the advantage that it is inexpensive and inspection of welded parts is easy. In tests conducted by the present inventors, it has been found that when the radius of curvature of the corners is in the range of 1.0 to 5.0 times the plate thickness t, welding costs can be significantly reduced and welding defects are less likely to occur.

In this way, by making the axis of the flange coincide or almost coincide with the axis of the fitting joint, an extremely large yield strength can be obtained for the hoop tension.

Next, FIGS. 6 and 7 are plan views of the square steel pipe sheet piles 37 shown in FIG. structure can be constructed economically. This example has strong resistance to hoop tension in the direction of the mating joint, so
There is no need to apply filling concrete to prevent deformation like the steel pipe sheet pile 8 shown in FIG. 14 described above.

Moreover, FIG. 8 is a schematic plan view showing a situation in which a continuous underground wall 61 for the foundation of a large building is constructed using square steel pipe sheet piles 37, and shows the square steel pipe sheet piles 62a to 6 at the corners.
2d is a female joint 6 that protrudes diagonally at 135 degrees from the corner.
3a, 63b (represented by square steel pipe sheet pile 62c)
and is fitted with male joints 64a, 64b of adjacent square steel pipe sheet piles 37a, 37b. For this type of joint, it is often convenient to use a pipe joint that is highly responsive to construction errors. Other joints can be freely employed as long as they have strength within a range that does not depart from the purpose of the present invention.

Next, FIG. 9 is a partial schematic diagram of a continuous underground wall 65 constructed using square steel pipe sheet piles according to the present invention in the same manner as in FIG. An example using 67 is shown below.

As described above in detail, the square steel pipe sheet pile of the present invention allows large structures to be manufactured quickly and economically.

(Effects of the Invention) The square steel pipe sheet pile of the present invention has excellent physical properties that can be applied to heavy-load structures that generate biaxial stress in the horizontal and vertical directions, and is also easy to construct on-site. Compared to its performance, the production cost is low and its practical value is high, and the economic effect is great.

[Brief explanation of drawings]

Figures 1, 2, 3, and 4 are schematic plan views showing examples of square steel pipe sheet piles according to the present invention, and Figure 5 is a partial explanatory diagram of the welded portions of square steel pipe corners and fitting joints. , FIG. 6, FIG. 7, and FIG. 8 are schematic plan views of a structure constructed using the square steel pipe sheet piles of the present invention, FIG. 10
Figure 11 is a schematic perspective view of a large cell constructed using conventional steel sheet piles, Figure 12 is a schematic perspective view of a large cell with a steel pipe structure, and Figures 13 a to d are straight lines with reinforcing materials. FIG. 14 is a schematic plan view of a well-known steel pipe sheet pile, and FIG. 15 is a schematic plan view of a box-type square steel pipe sheet pile. 1, 2... Cell, 3... Straight steel sheet pile, 4...
Reinforcement material, 5... Straight steel sheet pile, 6... Round steel pipe, 7
a, 7b...Joint, 8, 8b...Steel pipe sheet pile, 9...
... Cell, 10a, 10b ... Scalene angle steel, 11
...Steel sheet pile, 12...T-shaped steel, 13a, 13b...
...Angle steel, 14... Steel sheet pile, 15... Channel steel, 1
6a, 16b...Angle steel, 17...Steel sheet pile, 18
...Rip channel steel, 19a, 19b...Angle steel,
20...Steel sheet pile, 21a, 21b...Rectangular steel bar,
22a, 22b... steel pipe, 23a, 23b... flange steel plate, 24a, 24b... web steel plate, 2
5...Square steel pipe sheet pile, 26...Square steel pipe sheet pile, 27...
... Square steel pipe body, 28a, 28b ... Flange, 2
9a, 29b... Corner, 30a, 30b... Fitting joint, 31... Square steel pipe sheet pile, 32... Square steel pipe body, 33a, 33b... Flange, 34a, 34
b... Corner, 35a, 35b... Fitting joint, 3
6, 37, 37a, 37b...Square steel pipe sheet pile, 38
... Square steel pipe body, 39 ... Flange, 40a, 4
0b... corner, 41... round steel bar, 42... arm, 43... male joint, 44... steel pipe, 45... slit, 46... arm, 47... female joint, 48
... Square steel pipe body, 49a, 49b ... Corner, 50
... Small diameter steel pipe, 51 ... Arm, 52 ... Male joint, 53 ... Slit, 54 ... Large diameter steel pipe, 55
... Arm, 56 ... Female joint, 57 ... Flange, 58 ... Welded metal, 59 ... Earth retaining, 60 ...
Large cell, 61... Continuous underground wall, 62a to 62d
...Square steel pipe sheet pile, 63a, 63b...Female joint, 6
4a, 64b...Male joint, 65...Continuous underground wall,
66a, 66b...Female joint, 67...Steel pipe sheet pile.

Claims (1)

[Scope of Claims] 1. A square steel pipe sheet pile comprising a square steel pipe body and a fitting joint welded to both corner portions of one flange side of the square steel pipe body. 2. The square steel pipe sheet pile according to claim 1, wherein the fitting joints are the same type of interlocking fitting joints. 3. The square steel pipe sheet pile according to claim 1, wherein the square steel pipe has a square, rectangular or trapezoidal cross section. 4 The radius of curvature of the corners at both ends of the square steel pipe is 1.0 or more than the plate thickness.
The square steel pipe sheet pile according to claim 1, which is 5.0 times larger. 5. The square steel pipe sheet pile according to claim 1 or 4, wherein the square steel pipe main body is a square steel pipe formed by molding an electric resistance welded steel pipe.