JP7525789B2 - Connection structure and method for steel pipe and precast member - Google Patents

Description

The present invention relates to a connection structure and a connection method for steel pipes and precast members used in seawalls and beam-column structures.

In the fields of architecture and civil engineering, there is known technology for constructing seawalls, beam-column structures, and the like, using pile foundations that protrude above ground and a structure (foundation body) that is connected to the heads (pile heads) of the pile foundations. For example, Patent Document 1 discloses a connection structure (connection structure) between a footing installed at the bottom of a structure and a pile installed at the bottom of the footing. The connection structure described in Patent Document 1 reliably supports a structure, can withstand earthquake forces, and realizes a structure that is easy to construct and economical.

In recent years, from the standpoint of ease of construction and shortening construction time, a technique has become common for constructing various structures using so-called precast concrete members (also simply called precast members), in which members prefabricated in a factory or other location are brought to the site and assembled to existing members. Therefore, a connection structure can be considered in which a precast member with an opening for inserting the pile foundation is installed on top of the pile foundation and then fixed in place with mortar or the like.

JP 2004-132009 A

When constructing a connection structure using precast members and foundation piles (steel pipe piles, etc.), a large opening is required, so measures are taken such as fitting large precast members around the foundation piles. With large precast members, the thickness around the opening is made larger than the width of the pile foundation, and the larger the pile diameter of the pile foundation, the larger the precast members will be, raising concerns about increased costs.

In this regard, the connection structure described in Patent Document 1 uses steel connecting members with a smaller outer diameter than the steel pipe pile, thereby preventing the precast members from becoming larger, and improving workability and economy. On the other hand, the technology in Patent Document 1 has a configuration in which a specified gap is provided between the footing and the pile and the concrete in the pile, and there is no contact between the footing and the pile and the concrete in the pile, except for the steel connecting members. This has the effect of preventing fatal damage such as the collapse of the structure during an earthquake, but since there is no contact between the footing and the pile and the concrete in the pile, compressive stress is not transmitted due to contact between the concrete, and there is a risk that the bending strength of the entire connection structure will not be sufficiently guaranteed.

Furthermore, after extensive research by the inventors, it was found that if foundation piles (steel pipes, steel pipe piles, etc.) were to come into direct contact with precast concrete members, localized bearing pressure would be generated at the contact points, raising concerns that cracks would form in the precast concrete members.

In view of the above circumstances, the object of the present invention is to provide a connection structure and a method for connecting steel pipes and precast members that uses a connection member with a smaller outer diameter than the steel pipe when constructing a connection structure between the steel pipes and precast members, is easy to install and economical, and can fully ensure the bending strength of the connection structure without direct contact between the steel pipes and the precast members.

In order to achieve the above-mentioned object, according to the present invention, there is provided a connection structure comprising a precast concrete member, a steel pipe, and a connection member arranged across the precast member and the steel pipe, wherein one end of the connection member is contained within the steel pipe, and the other end of the connection member is contained within an insertion hole formed in the precast member, the connection member is fixed by a time-hardening material filled within the steel pipe and the insertion hole, a part of the connection end face of the precast member and an end face of the time-hardening material filled within the insertion hole are in direct contact with the end face of the time-hardening material filled within the steel pipe, and a contact avoidance means is provided between the connection end face of the precast member and the end face of the steel pipe to avoid direct contact , the precast member is a wall structure comprising a bulge portion as a lower structure and a panel portion as an upper structure, the thickness of the bulge portion is configured to be thicker than the thickness of the panel portion, and the insertion hole is formed in the bulge portion .

The contact avoidance means may be a cushioning material applied to the end face of the steel pipe.

The contact avoidance means may be a circular cutout formed on the end face of the precast member and corresponding to the shape of the end face of the steel pipe.

The contact avoidance means is a time-hardening material that covers the end surface of the steel pipe, and the time-hardening material may be integrated with the time-hardening material filled inside the steel pipe.

The insertion hole formed in the precast member may be a through hole that passes through the precast member.

According to another aspect of the present invention, there is provided a connection method for connecting a precast member and a steel pipe using the above-described connection structure, characterized in that the steel pipe is installed at a desired position, one end of the connection member is enclosed in the steel pipe and the other end is arranged protruding from the steel pipe, the precast member is moved so that the other end of the connection member is inserted into the insertion hole, and with the other end of the connection member enclosed in the insertion hole, a time-hardening material is filled into the insertion hole, and the precast member and the steel pipe are integrated together.

The present invention also provides a connection method for connecting a precast member and a steel pipe using the above-described connection structure, which is characterized in that the steel pipe is installed at a desired position, one end of the connection member is placed inside the steel pipe and the other end is placed protruding from the steel pipe, a formwork sheath tube having an outer diameter larger than the steel pipe is inserted outside the tip of the steel pipe, a time-hardening material is filled inside the steel pipe and the formwork sheath tube, the precast member is moved so that the other end of the connection member is inserted into the insertion hole, the time-hardening material is filled into the insertion hole with the other end of the connection member contained in the insertion hole, and the precast member and the steel pipe are integrated together.

According to the present invention, when constructing a connection structure between a steel pipe and a precast member, the connection is made using a connection member with an outer diameter smaller than that of the steel pipe, and a connection structure and connection method therefor are provided that are excellent in workability and economy, and can fully ensure the bending strength of the connection structure without direct contact between the steel pipe and the precast member.

1 is a schematic cross-sectional side view of a seawall constructed using a connection structure according to a first embodiment of the present invention. 1 is a schematic front cross-sectional view of a seawall constructed using a connection structure according to a first embodiment of the present invention. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is a schematic explanatory diagram showing a method for constructing a seawall according to the first embodiment. FIG. 2 is an explanatory diagram relating to a force transmission mechanism in the seawall according to the first embodiment. FIG. 2 is an explanatory diagram relating to a force transmission mechanism in the seawall according to the first embodiment. 11 is a schematic explanatory diagram of a beam-column structure constructed using a connection structure according to a second embodiment of the present invention. FIG. FIG. 1 is a schematic cross-sectional plan view of a beam-column structure. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. 13 is a schematic explanatory diagram showing a method for constructing a beam-column structure according to the second embodiment. FIG. FIG. 11 is a schematic explanatory diagram of a connection structure according to a first modified example of the present invention. FIG. 11 is a schematic explanatory diagram of a connection structure according to a second modified example of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. Note that in this specification and the drawings, components that have substantially the same functional configuration may be given the same reference numerals to avoid repeated explanation. In other words, in the following specification, components that are common to each embodiment may be illustrated with the same reference numerals, and their explanation may be omitted. Also, for the sake of explanation, the ground and ground surface may not be illustrated.

<First embodiment: seawall>
(Configuration of seawall)
1 and 2 are schematic explanatory diagrams of a seawall 10 consisting of one or more panel members 10a constructed using a connection structure 1 according to a first embodiment of the present invention, with Fig. 1 being a schematic side cross-sectional view and Fig. 2 being a schematic front cross-sectional view. Fig. 2 shows a state in which a plurality of (three) panel members 10a are installed side by side.

As shown in Figures 1 and 2, the seawall 10 (panel member 10a) comprises one or more steel pipe piles 12, which are cylindrical steel pipes driven into the ground as foundation piles, a concrete precast member 20 provided above the steel pipe pile 12, and a connecting member 30 installed protruding upward from inside the steel pipe pile 12. There are no particular limitations on the method of driving the steel pipe pile 12 into the ground. The precast member 20 may be a wall structure consisting of a bulging portion 20a as a lower structure and a panel portion 20b as an upper structure, in which case the bulging portion 20a is thicker than the panel portion 20b.

Here, the bulging portion 20a of the precast member 20 has an insertion hole 22 that opens up and down in the vertical direction, and the internal space of the insertion hole 22 is arranged so that it passes through the inside of the steel pipe pile 12. The seawall 10 is configured so that, with the precast member 20 installed above the steel pipe pile 12, these insertion holes 22 and the inside of the steel pipe pile 12 are filled with time-hardening material U to form an integrated structure.

When constructing the seawall 10, the connection member 30 is inserted so as to penetrate the internal space of the insertion hole 22 and the internal space of the steel pipe pile 12, and then the internal spaces are filled with a time-hardening material U. The time-hardening material U may be, for example, concrete, mortar, grout, etc., and the connection member 30 may be, for example, a steel member such as an H-shaped steel or an I-shaped steel.

In addition, at the connection point between the precast member 20 and the steel pipe pile 12 (the connection end surface near the ground surface), the precast member 20 and the steel pipe pile 12 are not in contact with each other strictly speaking. That is, the insertion hole 22 provided in the precast member 20 communicates with the inside of the steel pipe pile 12, and is integrated by filling the insertion hole 22 with a time-hardening material U and hardening it, but a contact avoidance means is provided so that the upper end surface of the steel pipe pile 12 (the upper end of the annular steel pipe) and the connection end surface of the precast member 20 do not come into direct contact with each other. In the configuration according to this embodiment, as shown in Figs. 1 and 2, an annular buffer material 40 is applied to the upper end surface of the steel pipe pile 12 as a contact avoidance means, and the steel pipe pile 12 and the precast member 20 are integrated with the buffer material 40. The buffer material 40 is, for example, resin or rubber applied to the end surface of the steel pipe pile 12.

In other words, in the space where the insertion hole 22 provided in the precast member 20 is connected to the inside of the steel pipe pile 12, if the time-hardening material inside the steel pipe pile 12 is U1 and the time-hardening material inside the insertion hole 22 is U2, a part of the connection end face (bottom surface) of the precast member 20 and the end face (bottom surface) of the time-hardening material U2 are in direct contact (adherent adhesion) with the time-hardening material U1, but there is no direct contact between the connection end face of the precast member 20 and the upper end face of the steel pipe pile 12 due to the presence of the buffer material 40.

In addition, multiple main reinforcing bars 50 extending vertically are provided inside the precast member 20 to improve strength. Furthermore, multiple shear reinforcement bars 53 configured in a horizontal, approximately circular shape to bundle the multiple main reinforcing bars 50 are provided inside the bulging portion 20a. Note that the number and shapes of these main reinforcing bars 50 and shear reinforcement bars 53 are not limited to the configurations shown in Figures 1 and 2, but are designed as desired to match the shape and configuration of the precast member 20.

In the seawall 10 configured as described with reference to Figures 1 and 2, the construction of the entire seawall 10 using the steel pipe piles 12, connecting members 30, and time-hardening material U is carried out on-site. On the other hand, the precast members 20 themselves are manufactured in advance in a factory or the like and transported to the site for use. In other words, the use of precast members 20 improves the efficiency of construction and shortens the construction period. In particular, when high members such as the panel portion 20b are manufactured on-site, they must be constructed using scaffolding, and various processes such as assembling and dismantling the scaffolding are required, so there is a great advantage to using the half-precast structure of the seawall 10 using the precast members 20.

In addition, in the seawall 10 according to this embodiment, when connecting the steel pipe pile 12 and the precast member 20, a connection structure 1 is used that uses a connection member 30 that is inserted so as to pass through the internal space of the insertion hole 22 and the internal space of the steel pipe pile 12, and a time-hardening material U that covers the periphery. This realizes a connection structure 1 that ensures sufficient bending strength without making the precast member 20 larger than necessary, and realizes a structure that is easy to construct and economical. In addition, in the configuration according to this embodiment, a buffer material 40 is interposed between the steel pipe pile 12 and the precast member 20 as a contact avoidance means. This makes it possible to avoid problems such as local bearing pressure occurring at the contact point when the steel pipe pile 12 and the precast member 20 made of concrete are brought into direct contact with each other, causing cracks in the precast member 20.

(How to construct seawalls)
The method for constructing the seawall 10 according to this embodiment is as follows. Figures 3 to 9, which will be referred to below, are schematic explanatory diagrams showing the method for constructing the seawall 10 according to the first embodiment, and the construction method will be described below with reference to Figures 3 to 9.

First, as shown in FIG. 3, a steel pipe pile 12 is driven into the ground. Then, a connecting member 30 is placed so that it protrudes a predetermined length from the inside of the steel pipe pile 12 to the ground surface. Here, the steel pipe pile 12 is driven so that its entirety is buried in the ground, and a circular buffer material 40 is attached to the upper end surface of the steel pipe pile 12 as a contact avoidance means.

Next, as shown in FIG. 4, the inside of the steel pipe pile 12 is filled with time-hardening material U1. The top surface of the filled time-hardening material U1 is made to be at roughly the same height level as the ground surface. This fixes the connecting member 30 arranged to protrude from the inside of the steel pipe pile 12. Note that, while soil and sand may get into a part of the lower internal space inside the steel pipe pile 12 when it is driven, it is sufficient to secure a space high enough to accommodate the connecting member 30.

Next, as shown in FIG. 5, the precast member 20 with the insertion hole 22 formed therein is lowered from above the steel pipe pile 12, and the upper part of the connection member 30 is inserted into the insertion hole 22. Then, as shown in FIG. 6, the connection end surface (lower surface) of the precast member 20 is installed so as to be in close contact with the upper surface (surface) of the time-hardening material U1 filled inside the steel pipe pile 12. On the other hand, since the upper end surface of the steel pipe pile 12 is provided with the buffer material 40, the precast member 20 does not come into contact with the upper end surface of the steel pipe pile 12 itself, and the steel pipe pile 12 and the precast member 20 are in a non-contact relationship via the buffer material 40.

As shown in FIG. 7, with the precast member 20 installed on the steel pipe pile 12, the time-hardening material U2 is filled into the insertion hole 22 from the upper opening of the insertion hole 22. As shown in the figure, the lower surface of the time-hardening material U2 comes into close contact with a part of the upper surface of the time-hardening material U1, and is integrated with it by hardening. Note that FIG. 8 is a schematic plan cross-sectional view of the seawall 10, where (a) shows the A-A cross section of FIG. 7 and (b) shows the B-B cross section of FIG. 7. Also, FIG. 9 is a schematic front cross-sectional view of the seawall 10. The shape of the insertion hole 22 is arbitrary, but as shown in FIG. 8(a), from the viewpoint of being able to insert the connection member 30 and suppressing the filling amount of the time-hardening material U2, if the connection member 30 is an H-shaped steel, it is preferable that the cross section be rectangular.

The seawall 10 is constructed by the method described above with reference to Figures 3 to 9. The seawall 10 constructed in this way ensures sufficient bending strength in the connection structure 1. The mechanism behind this is described below with reference to the drawings.

(Force transmission mechanism in seawalls)
Figures 10 and 11 are explanatory diagrams relating to the force transmission mechanism when the seawall 10 according to this embodiment is in use. Note that Figure 11 is an enlarged view of a portion of Figure 10, and in addition to the seawall 10, Figures 10 and 11 also show the distribution of the applied load W acting on the members.

As shown in Figures 10 and 11, when a force is applied to the seawall 10 due to a tsunami or the like, the connection end face of the precast member 20 and the time-hardening material U1 inside the steel pipe pile 12 are in direct contact, and when bending is applied, the force is transmitted so that the compressive force is borne by the time-hardening material such as concrete, and the tensile force is borne by the connection member 30.

The elastic modulus of the time-hardening material U such as concrete and the steel pipe pile 12 differs by about 10 times, and the material of the steel pipe pile 12 is generally harder. When force is applied to the seawall 10, the precast member 20 is bent, and if it is in direct contact with the steel pipe pile 12, there is a concern that cracks will occur at the contact point due to the localized force. Therefore, in this embodiment, a ring-shaped buffer material 40 is applied to the upper end surface of the steel pipe pile 12 as a contact avoidance means. On the other hand, since the connection end surface of the precast member 20 and the time-hardening material U1 inside the steel pipe pile 12 are in direct contact with each other, it is considered that force is transmitted sufficiently as shown in Figures 10 and 11, and sufficient bending strength is ensured.

To prevent cracks from occurring, the elastic modulus of the buffer material 40 must be smaller than that of time-hardening materials such as concrete. In addition, the buffer material 40 must be strong enough to function as a formwork for the upper end of the steel pipe pile 12 when filled with the time-hardening material U, and specifically, it is preferable for the buffer material 40 to be made of resin or rubber.

<Second embodiment: beam-column structure>
(Beam-column structure configuration)
Fig. 12 is a schematic explanatory diagram of a beam-column structure 60 constructed using a connection structure 1 according to a second embodiment of the present invention. Fig. 13 is a schematic plan sectional view of the beam-column structure 60, where (a) shows the A-A section in Fig. 12 and (b) shows the B-B section in Fig. 12. In the description of this embodiment, components having the same functional configuration as those in the first embodiment are illustrated with the same reference numerals, and their description may be omitted.

As shown in FIG. 12, the beam-column structure 60 includes a central steel pipe column 12a and a pair of precast beam members 65 (65a, 65b) at both ends. The steel pipe column 12a and the precast beam member 65 are connected via a connection structure 1 using a connection member 30. As shown in FIG. 13, each of the precast beam members 65a, 65b has an insertion hole formed in the center for filling with a time-hardening material U. As an example, a non-through hole 70 may be formed as an insertion hole in one precast beam member 65a, and a through hole 71 may be formed as an insertion hole in the other precast beam member 65b.

In the beam-column structure 60, two connection members 30 (30a, 30b) are included inside both ends of the steel pipe column 12a and at positions where they are inserted across the non-through hole 70 and the through hole 71. The non-through hole 70, the through hole 71, and the internal space of the steel pipe column 12a are inserted, and the interior is filled with a time-hardening material U.

Here, contact avoidance means are provided between both end faces of the steel pipe column 12a and the precast beam members 65a, 65b to prevent direct contact between the two. Specifically, annular cushioning materials 40 (40a, 40b) are provided on both end faces of the steel pipe column 12a as contact avoidance means, and the steel pipe column 12a and the precast beam members 65a, 65b are integrated through the cushioning materials 40 (40a, 40b).

As shown in FIG. 13, the cross-sectional shape of the non-through holes 70 and through holes 71 is preferably rectangular, as in the first embodiment. In addition, multiple main reinforcement bars and shear reinforcement bars (not shown) may be provided inside the precast beam members 65a and 65b, and the number and shape of the bars can be designed as desired.

In the beam-column structure 60 configured as shown in Figures 12 and 13, the entire beam-column structure 60 is constructed on-site using the steel pipe column 12a, the connection members 30 (30a, 30b), and the time-hardening material U. On the other hand, the precast beam members 65a, 65b themselves are manufactured in advance at a factory or the like and transported to the site for use. This improves the efficiency of construction and shortens the construction period. In addition, a connection structure 1 is realized that ensures sufficient bending strength without making the precast beam members 65a, 65b larger than necessary, resulting in a structure with excellent workability and economy. In addition, a buffer material 40 (40a, 40b) is interposed between the steel pipe column 12a and the precast beam members 65a, 65b as a contact avoidance means. This makes it possible to avoid problems such as local support pressure occurring at the contact points when the steel pipe column 12a and the precast beam members 65a, 65b made of concrete are brought into direct contact with each other, causing cracks in the precast beam members 65.

(How to build a beam-column structure)
The method for constructing the beam-column structure 60 according to this embodiment is as follows. Figures 14 to 21, which will be referred to below, are schematic explanatory diagrams showing the method for constructing the beam-column structure 60 according to the second embodiment, and the construction method will be described below with reference to these Figures 14 to 21.

First, as shown in FIG. 14, a first precast beam member 65a having a non-through hole 70 formed therein is installed in a predetermined position. Then, as shown in FIG. 15, a connecting member 30a is placed in the non-through hole 70 so that a predetermined upper length of the connecting member 30a protrudes upward from the first precast beam member 65a. In this state, the non-through hole 70 is filled with time-hardening material U3 (U).

Next, as shown in FIG. 16, the steel pipe column 12a is placed on the upper surface of the first precast beam member 65a so as to enclose the connection member 30a. Both end surfaces of the steel pipe column 12a are provided with cushioning materials 40 (40a, 40b) as contact avoidance means, so that the lower end surface of the steel pipe column 12a and the first precast beam member 65a do not come into direct contact with each other.

Next, as shown in FIG. 17, the steel pipe column 12a is filled with time-hardening material U4 (U) to a predetermined height. At this time, it is necessary to provide a certain amount of unfilled space of the time-hardening material U at the upper end side of the interior of the steel pipe column 12a in order to place the connecting member 30b. Then, as shown in FIG. 18, the connecting member 30b is placed at the upper end side of the steel pipe column 12a so that a portion of it is contained within the interior of the steel pipe column 12a.

Then, as shown in FIG. 19, the time-hardening material U4'(U) is filled into the steel pipe column 12a with a part of the connection member 30b contained within the steel pipe column 12a. As a result, the connection member 30b is fixed with a part protruding from the upper end of the steel pipe column 12a. Next, as shown in FIG. 20, the connection member 30b is contained within the through hole 71, and the second precast beam member 65b is lowered from above to a position where the connection member 30b contacts the buffer material 40b applied to the upper end surface of the steel pipe column 12a. At that time, the upper end surface of the steel pipe column 12a and the second precast beam member 65b are not in direct contact with each other due to the buffer material 40b previously applied to the upper end surface of the steel pipe column 12a.

Then, as shown in FIG. 21, the time-hardening material U5 is filled into the through hole 71 formed in the second precast beam member 65b from the upper opening of the through hole 71. Here, in this construction method, the non-through hole 70, the through hole 71, and the internal space of the steel pipe column 12a are inserted, and the time-hardening materials U3, U4 (including U4'), and U5 filled into these spaces are integrated and hardened. As a result, the first precast beam member 65a, the steel pipe column 12a, and the second precast beam member 65b are integrated by the time-hardening material U, and the beam-column structure 60 is constructed. As described above, the construction method described with reference to FIGS. 14 to 21 constructs the beam-column structure 60 using the connection structure 1 according to this embodiment.

(Action and Effect)
According to the seawall 10 and beam-column structure 60 constructed using the connection structure 1 according to the embodiment of the present invention configured as described above, a construction method using precast members (precast members 20, precast beam members 65) is adopted, which improves the efficiency of construction and shortens the construction period, etc. Also, as described with reference to Figures 10 and 11, the steel pipe pile 12 and the precast members (precast members 20, precast beam members 65) are connected using the connection structure 1 combining the connection member 30 and the time-hardening material U, so that a structure with excellent workability and economy while ensuring bending strength is realized.

In addition, in both the seawall 10 and the beam-column structure 60, cushioning material 40 is provided between the steel pipe piles 12 or steel pipe columns 12a and the precast members (precast members 20, precast beam members 65) as a contact avoidance means, and a configuration is adopted in which the two do not come into direct contact. This makes it possible to avoid problems such as localized bearing pressure occurring at the contact points and cracks occurring when the steel pipe piles 12 or steel pipe columns 12a come into direct contact with the precast members (precast members 20, precast beam members 65) made of concrete.

Although one embodiment of the present invention has been described above, the present invention is not limited to the illustrated form. It is clear that a person skilled in the art can conceive of various modified or revised examples within the scope of the ideas described in the claims, and it is understood that these naturally fall within the technical scope of the present invention. Therefore, modified examples of the present invention will be described below with reference to the drawings. Note that in the following modified examples, components having the same functional configuration as the above-mentioned embodiments are illustrated with the same reference numerals, and their description may be omitted.

<Modification: Modification of Contact Avoidance Means>
In the connection structure 1 according to the above embodiment, a configuration in which the buffer material 40 is applied to the end surface of the steel pipe pile 12 or the steel pipe column 12a is illustrated and described as a contact avoidance means, but the contact avoidance means is not limited to this. Therefore, as a modification of the present invention, other configurations of the contact avoidance means will be described with reference to the drawings. Note that components having the same functional configuration as those in the above embodiment are illustrated with the same reference numerals, and their description may be omitted.

(First Modification)
FIG. 22 is a schematic diagram of the connection structure 1a according to the first modified example of the present invention, and shows an enlarged view of the connection portion between the precast member 20 and the steel pipe pile 12. As shown in FIG. 22, in this modified example, a notch 80, which is a circular groove, is formed on the end face (lower surface) of the precast member 20. The notch 80 is formed in a shape corresponding to the end face shape of the steel pipe pile 12, and the end face of the precast member 20 and the steel pipe pile 12 are not in direct contact with each other. On the other hand, the precast member 20 and the steel pipe pile 12 are integrally constructed because the time-hardening material U filled inside each of them is integrated, and even if the precast member 20 and the steel pipe pile 12 are not in direct contact with each other, they are integrally constructed as the connection structure 1a, and sufficient bending strength is ensured.

In this first modified example, a configuration in which a notch 80 is formed as a means for preventing contact between the precast member 20 and the steel pipe pile 12 is described, but a configuration in which a cushioning material is applied to the formed notch is also conceivable.

(Second Modification)
23 is a schematic explanatory diagram of a connection structure 1b according to a second modified example of the present invention, which shows an enlarged connection portion between a precast member 20 and a steel pipe pile 12. As shown in FIG. 23, in this modified example, the steel pipe pile 12 and the precast member 20 are not in contact with each other, and the time-hardening material U is configured to cover the inside of the steel pipe pile 12 as well as the upper end surface of the steel pipe pile 12. The time-hardening material U is configured as shown in the figure by filling and solidifying the time-hardening material U in a state where a formwork sheath pipe 90 having an outer diameter larger than that of the steel pipe pile 12 is inserted outside the tip of the steel pipe pile 12 so that the formwork sheath pipe 90 protrudes from the tip of the steel pipe pile 12 toward the precast member 20, and the time-hardening material U is constructed as an integral part of the time-hardening material U inside the steel pipe pile 12. That is, the time-hardening material U is filled inside the formwork sheath pipe 90 in a state where the outer diameter is larger than that of the steel pipe pile 12, and the upper end surface of the steel pipe pile 12 is covered with the time-hardening material U.

In this modified example, the formwork sheath tube 90 may be left in place after the time-hardening material U has hardened, or may be removed. The material of the formwork sheath tube 90 is not particularly limited as long as it has the strength required for the formwork when filling it with the time-hardening material U. For example, it may be made of a material with cushioning properties, such as resin or rubber, or it may be made of steel.

However, when using a steel formwork sheath pipe 90, a configuration is required that prevents localized pressure from occurring at the contact points between the formwork sheath pipe 90 and the precast member 20, which would cause cracks in the precast member. For example, when inserting the formwork sheath pipe 90 onto the steel pipe pile 12, the formwork sheath pipe 90 may be fixed to a minimum extent so that it can easily slide on the outer surface of the steel pipe pile 12 when a load is applied. As an example, the formwork sheath pipe 90 may be fixed to the steel pipe pile 12 with a minimum of spot welding.

In the above embodiment, the steel pipe piles 12 and steel pipe columns 12a, which are typical cylindrical steel pipes, are used as foundation piles, but the present invention is not limited to this. For example, steel pipes and steel pipe sheet piles of various shapes may be used as foundation piles.

The present invention can be applied to the connection structure and connection method between steel pipes and precast members used in seawalls and beam-column structures.

Reference Signs List 1...Connection structure 10...Tide embankment 12...Steel pipe pile 12a...Steel pipe column 20...Precast member 22...Insertion hole 30...Connection member 40, 40a, 40b...Buffer material 50...Main steel bar 53...Shear reinforcement bar 60...Beam-column structure 65 (65a, 65b)...Precast beam member 70...Non-through hole 71...Through hole 80...Notch 90...Formwork sheath tube U (U1 to U5)...Time-hardening material

Claims (7)

A connection structure comprising a concrete precast member, a steel pipe, and a connection member disposed across the precast member and the steel pipe,
One end of the connection member is contained within the steel pipe, and the other end of the connection member is contained within an insertion hole formed in the precast member,
The connection member is fixed by a time-hardening material filled in the inside of the steel pipe and the inside of the insertion hole,
a part of the connection end face of the precast member and an end face of the time-hardened material filled inside the insertion hole are in direct contact with an end face of the time-hardened material filled inside the steel pipe, and a contact avoidance means is provided between the connection end face of the precast member and the end face of the steel pipe to avoid direct contact ;
A connection structure characterized in that the precast member is a wall structure consisting of a bulge portion as a lower structure and a panel portion as an upper structure, the thickness of the bulge portion is configured to be thicker than the thickness of the panel portion, and the insertion hole is formed in the bulge portion . The connection structure according to claim 1, characterized in that the contact avoidance means is a cushioning material applied to the end face of the steel pipe. The connection structure described in claim 1, characterized in that the contact avoidance means is a circular cutout portion formed on the end face of the precast member and corresponding to the shape of the end face of the steel pipe. The connection structure described in claim 1, characterized in that the contact avoidance means is a time-hardening material covering the end surface of the steel pipe, and the time-hardening material is integrated with the time-hardening material filled inside the steel pipe. The connection structure according to any one of claims 1 to 4, characterized in that the insertion hole formed in the precast member is a through hole penetrating the precast member. A connection method for connecting a precast member and a steel pipe using the connection structure according to any one of claims 1 to 5,
The steel pipe is installed at a desired position,
In a connection member in which one end is contained in the steel pipe and the other end is arranged protruding from the steel pipe, the precast member is moved so that the other end of the connection member is inserted into the insertion hole;
A connection method characterized by filling the insertion hole with a time-hardening material while the other end of the connection member is enclosed in the insertion hole, thereby integrating the precast member and the steel pipe. A connection method for connecting a precast member and a steel pipe using the connection structure according to claim 4,
The steel pipe is installed at a desired position, and the connecting member is arranged so that one end is contained within the steel pipe and the other end protrudes from the steel pipe,
A formwork sheath pipe having an outer diameter larger than that of the steel pipe is inserted outside the tip of the steel pipe, and a time-hardening material is filled inside the steel pipe and the formwork sheath pipe in this state;
The precast member is moved so that the other end of the connecting member is inserted into the insertion hole;
A connection method characterized by filling the insertion hole with a time-hardening material while the other end of the connection member is enclosed in the insertion hole, thereby integrating the precast member and the steel pipe.

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