JP6415283B2 - Steel pipe connection structure and method for forming the same - Google Patents

Description

  The present invention relates to a steel pipe connection structure in which two or more steel pipes having a relatively large thickness are connected to each other, and a method for forming a steel pipe connection structure that forms the steel pipe connection structure inside a steel pipe installation hole. It is.

  When using a steel pipe for the foundation or earth retaining of a structure, such as when the steel pipe to be used has a length exceeding the specified length, or because a construction of a relatively short steel pipe in a construction hole due to restrictions at the construction site, etc. Under the environment, construction is performed in which two or more steel pipes are built in the erection hole while being connected on site.

  When the diameter of the steel pipe used is about 1000 mm or more, the wall thickness naturally increases, and a steel pipe with a thickness of 30 mm or more, or a steel pipe with a thickness of 40 mm or more is often used. .

  The connection between the above steel pipes is generally done by on-site circumferential welding such as self-shielded arc welding, but when welding steel pipes with a wall thickness of 30 mm or more, in addition to requiring a huge amount of time for welding, Whether or not the welding operation is possible is affected by the weather, and a welder having skilled skills is required. For example, in railway construction where there are many time restrictions on the construction, welding work that requires an enormous amount of time can be one of the factors for extending the construction period.

  Therefore, it is possible to shorten the work period by connecting the steel pipes using mechanical joints that have various forms instead of connecting the steel pipes with relatively thick walls by field welding. become.

  In this mechanical joint, a threaded end is provided at the joint end of the steel pipe, and both ends are screwed together and a shear key (transmission key) is inserted through the ends of both steel pipes to be connected. There is a form of a pin joint structure in which a groove to be inserted is provided and a transmission key is inserted into both grooves to connect steel pipes. This latter joint structure is referred to as a lacnican joint (registered trademark), and disclosed techniques relating to this are disclosed in Patent Documents 1 and 2 and the like.

  By the way, when the thickness of the steel pipe exceeds 30 mm, there is currently no commercially available mechanical joint with a wall thickness exceeding 30 mm.

  For example, when connecting steel pipes with a thickness of 30 mm with mechanical joints, it is possible to use commercially available mechanical joints, but when connecting steel pipes with a thickness of about 40 mm with mechanical joints, Since the thickness of the part remains at about 30 mm, the difference in thickness of about 10 mm or more occurs between the general steel pipe part and the joint part, and it is inevitable that the joint part becomes a weak structural part.

  Therefore, in the past, connection between steel pipes exceeding 30 mm has to be relied upon on-site welding, and the above-mentioned construction period has to be allowed to be extended.

JP 2000-319874 A JP 11-36285 A

  The present invention has been made in view of the problems described above, and when connecting thick steel pipes, a steel pipe connection structure in which the joint portion does not become a structural weak part while shortening the process by using a mechanical joint. It aims to provide a body and its formation method.

In order to achieve the above object, the steel pipe connection structure according to the present invention includes two or more steel pipes having a mechanical joint provided at a joint side end of a steel pipe connected to the other steel pipe. 1 or more steel pipe connection parts are formed, the steel pipe and the mechanical joint part have a welded part joined by welding, and the inner diameter of the steel pipe and the mechanical joint part in the welded part is the same, The thickness of the mechanical joint is thinner than the steel pipe, and two or more divided pipes are arranged to cover the outside of the steel pipe connecting part, and the two or more divided pipes are connected to the steel pipe and the steel pipe along their contours. A steel pipe reinforcement body is formed by welding to the joint, and the internal connection body connects both the steel pipe connection section and the steel pipe reinforcement body so that the outer diameter of the steel pipe reinforcement body is approximately the same as the outer diameter of the steel pipe The steel pipe connection part and the steel pipe reinforcement are integrated by the internal connection body. Those that are configured.

  The steel pipe connection structure of the present invention is a steel pipe reinforcement in which two or more divided pipes are welded and joined to the outside of a steel pipe connection part formed by connecting two or more steel pipes between respective mechanical joint parts. In addition to the formation of the body, the steel pipe connection part and the steel pipe reinforcement body are connected to each other by the internal connection body between them, so that the steel pipe connection part and the steel pipe reinforcement body are integrated, and the steel pipe connection is achieved. This is a steel pipe connection structure in which the part is effectively a structural weak part.

  By reinforcing the steel pipe connecting portion with a steel pipe reinforcing body, the steel pipe that is a constituent element of the steel pipe connecting structure of the present invention is mainly a steel pipe having a relatively large thickness, and includes a steel pipe having a thickness of 30 mm or more. . However, this does not exclude steel pipes with a relatively thin wall thickness of less than 30 mm.

  In addition, the “mechanical joint” includes various forms other than a welded joint. Both ends of the steel pipe are threaded, and the other end is screwed into one end. Examples include a form of connection and a form of a pin joint structure in which the grooves at the ends of both steel pipes are positioned and the transmission key is inserted into both the grooves to connect the steel pipes.

  For example, the above mechanical joint is connected to the end of a steel pipe by factory welding, etc., and the steel pipe with the mechanical joint is transported on-site and suspended in a construction yard or heavy machinery, and the mechanical type of two or more steel pipes. The joints are connected according to the joint mode and inserted into the steel pipe erection hole.

  The “two or more split pipes” include two half pipes, three or more split pipes, etc., but the connection between the split pipes and the connection between the end of the split pipe and the steel pipe connecting portion It is preferable to apply two halves that shorten the weld length because they are performed by field welding.

  When the thickness of the steel pipe exceeds 30 mm, the thickness of the steel pipe connection portion formed by connecting the mechanical joint portions can be smaller than the thickness of the steel pipe. Therefore, by arranging a steel pipe reinforcement body composed of two or more divided pipes outside the steel pipe connection part, the wall thickness of the connection part is equal to the wall thickness of the steel pipe or as necessary. It is possible to make it thicker.

  However, simply connecting the contour edge of the steel pipe reinforcement to the steel pipe connection is not connected between the steel pipe reinforcement and the steel pipe connection, so the steel pipe reinforcement and the steel pipe connection are integrated. It is also assumed that buckling occurs when a compressive load is applied to the steel pipe reinforcement. In addition, since the steel pipe reinforcement and the steel pipe connection part cannot be integrated, the cross-sectional rigidity of the steel pipe connection part cannot be said to be comparable to the cross-sectional rigidity of the general part of the steel pipe. In terms of yield strength and the like, it must be said that the steel pipe connection portion becomes a structural weak portion.

  Therefore, in the steel pipe connection structure of the present invention, the steel pipe connection portion and the steel pipe reinforcement body are integrated by forming an internal connection body that connects both between the steel pipe connection portion and the steel pipe reinforcement body. A steel pipe connection structure is obtained in which the steel pipe connection portion does not become a structural weak portion.

  Here, as embodiments of the “internal connection body”, for example, the following two embodiments can be cited.

  One form of the internal connection body is one in which the internal connection body is formed from an adhesive filler filled between the steel pipe connection portion and the steel pipe reinforcement.

  Examples of the adhesive filler include mortar, cement, and concrete.

  Adhesive filler is filled between the steel pipe connection part and the steel pipe reinforcement body, and the steel pipe connection part and the steel pipe reinforcement body can be connected on their entire surface by hardening, and the steel pipe connection part and the steel pipe reinforcement body are high. Integration can be achieved.

  Further, another form of the internal connection body is formed by plug welding in which the internal connection body connects the steel pipe connection portion and the steel pipe reinforcement body through the holes on the premise that the split pipe has a plurality of holes. It is what has been.

  By performing plug welding through a plurality of holes provided in the divided pipe, the steel pipe connecting portion and the steel pipe reinforcing body can be spot-connected at the positions of the holes.

  The present invention also extends to a method for forming a steel pipe connection structure, which includes two or more steel pipes provided with a mechanical joint at the joint side end of the steel pipe connected to the other steel pipe. Are connected by mechanical joints to form a steel pipe connection part, and a steel pipe connection intermediate structure in which two or more steel pipes are connected by one or more steel pipe connection parts is formed in advance. The first step of building the structure into the steel pipe installation hole, two or more divided pipes are arranged outside the steel pipe connecting portion of the steel pipe connecting intermediate structure, and the two or more divided pipes are arranged along their contours. A second step of forming a steel pipe reinforcement on the outside of the steel pipe connection by welding to the connection, forming an internal connection that connects both the steel pipe connection and the steel pipe reinforcement, the internal connection The steel pipe connection is made by integrating the steel pipe connection part and the steel pipe reinforcement body. It is made of a third step of forming a structure.

  The timing of the construction of the steel pipe erection hole and the construction of the steel pipe connection intermediate structure in the first step is diverse, and the steel pipe connection intermediate structure suspended by heavy machinery is built in sequence while the steel pipe erection hole is sequentially created. And a method of building a steel pipe connecting intermediate structure at once after building a steel pipe erection hole to a predetermined flooring level.

  According to the method for forming a steel pipe connection structure of the present invention, since the steel pipes are connected to each other via a mechanical joint portion, the work period can be significantly shortened as compared with welding connection, and a thick steel pipe is formed. Even when it is set as a construction target, a steel pipe connection structure in which the steel pipe joint portion does not become a structural weak portion can be formed.

  In addition, in this method of forming a steel pipe connection structure, two embodiments can be given as a method of forming an internal connection, and one of the forms is that in the third step, the steel pipe connection portion and the steel pipe reinforcement are provided. An internal connection body is formed by filling an adhesive filler between the bodies. According to another aspect, in the second step, a steel pipe reinforcing body is formed using a split pipe having a plurality of holes, and in the third step, the steel pipe connecting portion and the steel pipe are formed via the holes. The reinforcing bodies are connected by plug welding, and the internal connection body is formed by plug welding.

  As can be understood from the above description, according to the steel pipe connection structure of the present invention and the method for forming the steel pipe connection structure, the steel pipe connection portion formed by connecting two or more steel pipes between the mechanical joint portions, In addition to the fact that a steel pipe reinforcement body formed by welding and joining two or more divided pipes to the outside is formed, the steel pipe connection portion and the steel pipe reinforcement bodies are connected by an internal connection body between them, By connecting the mechanical joints, the construction period can be greatly shortened, and even when the steel pipe is thick, the steel pipe reinforcement disposed on the outer periphery of the steel pipe connection part is connected via the internal connection body. It is effectively eliminated that the steel pipe connection part becomes a structural weak part.

It is the figure explaining the 1st step of embodiment of the formation method of the steel pipe connection structure of the present invention, and is the figure explaining the mechanical joint part of two steel pipes to be connected. It is the figure explaining the 1st step of the formation method following Drawing 1, and is the figure showing the steel pipe connection intermediate structure. It is a figure explaining the 2nd step of the formation method of a steel pipe connection structure, and is a figure explaining the situation where two divided pipes (half pipe) to be connected are attached. It is the figure explaining the 2nd step of the formation method following FIG. 3, Comprising: It is the figure which showed the condition in which the steel pipe reinforcement body was formed in the outer side of the steel pipe connection part. It is the figure explaining the 3rd step of the formation method of a steel pipe connection structure, and is the figure showing the situation where the steel pipe connection structure was formed. It is VI-VI arrow line view of FIG. It is the figure which showed the state in which the steel pipe connection structure is formed in the ground.

  Embodiments of a steel pipe connection structure and a method for forming the same according to the present invention will be described below with reference to the drawings. In addition, although the mechanical joint of the example of illustration is a lacnican joint, it cannot be overemphasized that various other mechanical joints are applicable.

(Embodiment of steel pipe connection structure and its forming method)
1 to 5 are flow charts explaining the steel pipe connection structure of the present invention and the forming method thereof in that order. More specifically, FIG. 1 is a diagram illustrating a first step of the embodiment of the forming method, and is a diagram illustrating a mechanical joint portion of two steel pipes to be connected. FIG. It is the figure explaining the 1st step of the formation method following, and is a figure showing the steel pipe connection intermediate structure. FIG. 3 is a diagram illustrating a second step of the method for forming the steel pipe connection structure, and is a diagram illustrating a situation where two divided pipes (half pipes) to be connected are attached, and FIG. It is the figure explaining the 2nd step of the formation method following FIG. 3, Comprising: It is the figure which showed the condition in which the steel pipe reinforcement body was formed in the outer side of the steel pipe connection part. Furthermore, FIG. 5 is a figure explaining the 3rd step of the formation method of a steel pipe connection structure, Comprising: It is the figure which showed the condition in which the steel pipe connection structure was formed. 6 is a view taken along the line VI-VI in FIG. 5, and FIG. 7 is a view showing a state in which the steel pipe connection structure is formed in the ground.

  In the method for forming a steel pipe connection structure according to the present invention, a steel pipe connection structure is formed in the ground by connecting two or more steel pipes with mechanical joints provided at their ends.

  FIG. 1 is an enlarged view of mechanical joints 2A and 2B at the ends of two steel pipes 1A and 1B connected to each other, and a part thereof is broken to show steel pipes 1A and 1B and a mechanical joint 2A. , 2B can be visually recognized, and only the ends of the steel pipes 1A, 1B are shown.

  Mechanical joints 2A and 2B are connected to the ends of the steel pipes 1A and 1B in advance at the factory or the like via the welded portion Y, and are transported on-site. Here, the thickness t1 of the steel pipes 1A and 1B is 30 mm or more, for example, a steel pipe having a large thickness of about 40 mm.

  One mechanical joint portion 2A has a groove 2Aa extending in the circumferential direction on the inner surface thereof. The groove 2Aa accommodates a load transmission key 2Ac fitted with a plurality of set bolts 2Ab at intervals, and the set bolt 2Ab Faces the bolt hole 2Ad that connects the groove 2Aa and the outer surface of the mechanical joint 2A.

  At the site, the mechanical joint 2A is fitted to the mechanical joint 2B, both grooves 2Aa and 2Ba are positioned, and an operator uses a hexagon wrench or the like to set the bolt 2Ab via the bolt hole 2Ad. , And the load transmission key 2Ac is set at a position straddling both the grooves 2Aa and 2Ba. As a result, as shown in FIG. 2, the steel pipes 1A and 1B are connected to each other via the steel pipe connection part 2 including the mechanical joint parts 2A and 2B.

  If three or more steel pipes are connected, the three steel pipes are connected via two steel pipe connection portions 2.

  Thus, the steel pipe connection intermediate structure 10 which consists of two or more steel pipes 1A and 1B and the steel pipe connection part 2 which connects each steel pipe 1A and 1B is formed in the field.

  Here, the steel pipe connection intermediate structure 10 is formed by using the steel pipe connection intermediate structure 10 formed at the site yard with respect to the steel pipe installation hole 20 (see FIG. 7) that has been previously built up to the flooring level. The steel pipe 1B is installed in the steel pipe installation hole that has been excavated halfway, and the other steel pipe 1A suspended by a heavy machine is connected to the steel pipe 1B in the steel pipe installation hole, and the remaining excavation. The method of forming the steel pipe connection intermediate structure 10 and the timing and the steel pipe installation hole 20 such as a method of forming the steel pipe connection hole to the flooring level and completing the installation of the steel pipe connection intermediate structure 10 at that stage There are various combinations of generation methods and timings (the first step of the method for forming the steel pipe connection structure).

  As shown in FIG. 6, the thickness t2 of the steel pipe connection portion 2 constituted by the mechanical joint portions 2A and 2B is thinner than the steel pipes 1A and 1B having the thick wall thickness t1, for example, the thickness t1 is 40 mm. On the other hand, the thickness t2 is at most about 30 mm. Therefore, since the thickness of the steel pipe connection part 2 is thin with respect to the general part of the steel pipes 1A and 1B, there is a possibility that the steel pipe connection part 2 becomes a structural weak part.

  Therefore, in order to reinforce the steel pipe connection part 2, as shown in FIG. 3, two half pipes (divided pipes) 3A and 3B are disposed outside the steel pipe connection part 2 of the steel pipe connection intermediate structure 10 (X direction).

  As shown in FIG. 4, two half pipes 3A and 3B are put on the outside of the steel pipe connection part 2, and these are connected to the steel pipe connection part 2 through the welded portion Y along the outline of the half pipes 3A and 3B. At the same time, the ends of the half pipes 3A and 3B are also connected to each other via the welded portion Y, so that the steel pipe reinforcing body 3 constituted by the half pipes 3A and 3B is attached to the outside of the steel pipe connecting portion 2. This construction is performed by a method in which the half pipes 3A and 3B are suspended in the steel pipe installation hole 20 by a heavy machine, and a worker on the workbench in the steel pipe connection portion 2 performs welding (the foregoing). The second step of the method for forming the steel pipe connection structure).

  The steel pipe reinforcement body 3 is attached to the outside of the steel pipe connection portion 2 in the second step. However, simply by connecting the contour edge of the steel pipe reinforcement body 3 to the steel pipe connection portion 2 by welding, the steel pipe reinforcement is performed. The body 3 and the steel pipe connection part 2 are not connected. Therefore, the steel pipe reinforcing body 3 and the steel pipe connecting portion 2 cannot be integrated, and it is assumed that the steel pipe reinforcing body 3 buckles when a compressive load is applied to the steel pipe reinforcing body 3. Further, since the steel pipe reinforcing body 3 and the steel pipe connecting portion 2 are not integrated, the cross-sectional rigidity of the steel pipe connecting portion 2 cannot be said to be comparable to the cross-sectional rigidity of the general steel pipes such as the steel pipes 1A and 1B. With regard to bending strength, buckling strength, and the like when acting, the steel pipe connection portion 2 can still be a weak structural portion.

  Therefore, as shown in FIG. 5, an internal connection body 4 is formed between the steel pipe connection portion 2 and the steel pipe reinforcement body 3 so as to connect both.

  Specifically, plug welding is performed in which the steel pipe connection portion 2 and the steel pipe reinforcing body 3 are formed at the positions of the plurality of holes 3a by performing plug welding through the plurality of holes 3a provided in the half pipes 3A and 3B. It is connected in a spot manner by the part 4 (internal connection body 4).

  By integrating the steel pipe connecting portion 2 and the steel pipe reinforcing body 3 by a large number of plug welds 4, a steel pipe connecting structure 100 in which the steel pipe connecting portion 2 does not become a structural weak portion is formed in the steel pipe erected hole 20. (Thus, the 3rd step of the formation method of a steel pipe connection structure).

  As shown in FIG. 6, with respect to the thickness t1 of the steel pipes 1A, 1B, the thickness t2 of the steel pipe connection part 2 composed of the mechanical joint parts 2A, 2B and the steel pipe connection part via the plug weld part 4 The sum of the thicknesses t3 of the steel pipe reinforcing bodies 3 integrally connected to 2 increases (t2 + t3 ≧ t1).

  Thus, by adjusting the thickness of the mechanical joints 2A and 2B to be used and the thickness of the half pipes 3A and 3B to the thick steel pipes 1A and 1B having the wall thickness t1, the steel pipe joints are adjusted as desired. Can be made the same thickness as the steel pipes 1A and 1B or thicker than the steel pipes 1A and 1B.

  In FIG. 7, a steel pipe connection structure 100 configured by connecting three steel pipes 1A, 1B, and 1C by two steel pipe joints is formed in a steel pipe installation hole 20 formed in the ground G. The form is shown.

  Here, although not shown in the drawings, in addition to the plug welded portion 4 in the illustrated example, an adhesive filler such as mortar, cement, or concrete is used for the internal connection body, and a steel pipe reinforcement body and a steel pipe in which no holes are formed. There is also a form in which the gap is filled between the connecting portions 2 and cured so as to integrate them.

  In this form, when connecting a steel pipe reinforcement to the outer side of the steel pipe connection part 2 by welding, it is necessary to ensure the filling port of a filler.

  Thus, according to the illustrated steel pipe connection structure 100 and its forming method, first, since both the steel pipes 1A and 1B are connected by the mechanical joint parts 2A and 2B, the ends of the steel pipe are connected by welding. The construction period can be greatly shortened compared to the method of doing this. Furthermore, even if the thickness of the steel pipes 1A and 1B to be connected is thick and the thickness of the mechanical joint portion is not the same as the thickness of the steel pipe, the steel pipe disposed on the outer periphery of the steel pipe connection portion 2 Since the reinforcing body 3 is integrated through the internal connection body 4, it is effectively eliminated that the steel pipe connection portion 2 becomes a structural weak portion.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

  1A, 1B, 1C ... Steel pipe, 2 ... Steel pipe connection part, 2A, 2B ... Mechanical joint part, 2Aa ... Groove, 2Ab ... Set bolt, 2Ac ... Load transmission key, 2Ad ... Bolt hole, 3 ... Steel pipe reinforcement, 3A 3B ... Half pipe (split pipe), 3a ... hole, 4 ... internal connection body (plug welded part), 10 ... steel pipe connection intermediate structure, 20 ... steel pipe installation hole, 100 ... steel pipe connection structure, Y ... Welded part, t1 ... thickness of steel pipe, t2 ... thickness of steel pipe connecting part, t3 ... thickness of steel pipe reinforcement

Claims (4)

Two or more steel pipes provided with a mechanical joint portion at the joint side end of the steel pipe connected to the other steel pipe are connected to each other by the mechanical joint portions to form one or more steel pipe connection portions,
The steel pipe and the mechanical joint have a weld joined by welding,
The inner diameter of the steel pipe and the mechanical joint in the weld is the same, and the thickness of the mechanical joint is thinner than the steel pipe.
Two or more split pipes are disposed so as to cover the outside of the steel pipe connection portion, and the two or more split pipes are welded and joined to the steel pipe and the steel pipe connection portion along their contours to form a steel pipe reinforcement.
An internal connection body is formed between the steel pipe connection portion and the steel pipe reinforcement body so that the outer diameter of the steel pipe reinforcement body is approximately the same as the outer diameter of the steel pipe,
A steel pipe connection structure in which a steel pipe connection portion and a steel pipe reinforcement are integrated by an internal connection body. Two or more steel pipes provided with a mechanical joint portion at the joint side end of the steel pipe connected to the other steel pipe are connected to each other by the mechanical joint portions to form one or more steel pipe connection portions,
Two or more divided pipes are disposed outside the steel pipe connecting portion, and the two or more divided pipes are welded and joined to the steel pipe connecting portion along their outlines to form a steel pipe reinforcing body,
An internal connection that connects both the steel pipe connection and the steel pipe reinforcement is formed,
The dividing tube has a plurality of holes,
The internal connection body is formed by plug welding that connects the steel pipe connection portion and the steel pipe reinforcement body through the hole ,
A steel pipe connection structure in which a steel pipe connection portion and a steel pipe reinforcement are integrated by an internal connection body. Two or more steel pipes provided with a mechanical joint portion at the joint side end of the steel pipe connected to the other steel pipe are connected to each other by mechanical joint portions to form a steel pipe connection portion. One or more steel pipe connection portions A steel pipe connection intermediate structure in which two or more steel pipes are connected in advance, and a first step of building the steel pipe connection intermediate structure in the steel pipe installation hole;
Two or more split pipes are disposed outside the steel pipe connection portion of the steel pipe connection intermediate structure, and the two or more split pipes are welded and joined to the steel pipe connection portion along their contours. A second step of forming a steel pipe reinforcement,
A third step of forming an internal connection body for connecting both the steel pipe connection portion and the steel pipe reinforcement body, and forming a steel pipe connection structure in which the steel pipe connection portion and the steel pipe reinforcement body are integrated by the internal connection body. A method for forming a steel pipe connection structure. In the second step, a steel pipe reinforcing body is formed using a divided pipe having a plurality of holes,
The method of forming a steel pipe connection structure according to claim 3, wherein, in the third step, the steel pipe connection portion and the steel pipe reinforcing body are connected by plug welding through the hole, and the internal connection body is formed by the plug welding. .

Images