JP4101077B2 - Core joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a joint portion of a core material for joining a core material arranged on the premise that a part is removed after use.
[0002]
[Prior art]
In a construction site, a core material such as H-shaped steel is sometimes installed in the ground to support a temporary stage for lining a road or a temporary pier. The core material is installed, for example, by drilling the ground, filling the hole with mortar, and building the core material. Moreover, in order to construct a soil cement underground wall, a core material such as H-shaped steel may be placed in the ground in which cement and earth and sand are mixed and stirred. Furthermore, a core material such as H-shaped steel may be placed in the ground as a support pile.
In this way, when the core material is placed in the ground and used, removal may be required after use. In particular, when a core material is placed under the road, it is required to remove all the core material from the ground surface to a depth of 3.5 m.
Conventionally, when removing a part of the core material that has been laid, excavate the ground to the depth to be removed, cut the exposed core material with a gas burner, etc., and lift the core material above the cutting part with a crane. It was removed.
In addition, as disclosed in Patent Document 1 or 2, there are several methods for providing a cutting portion in the core material in advance and releasing the connection with the reinforcing member that reinforces the cutting portion during use at the time of removal. There is.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-311150 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-13144
[Problems to be solved by the invention]
The above-described conventional structure of the joint portion of the core material and the method for extracting the core material have the following problems.
<I> It is necessary to excavate the ground to a depth at which the core material is removed, and to cut or disconnect the exposed core material.
<B> In the method of releasing the connection from the ground surface, it is necessary to extend and dispose the release mechanism from the connection part to the ground surface.
[0005]
OBJECT OF THE INVENTION
The present invention has been made in order to solve the above-described conventional problems, and provides a structure of a core material joint portion and a core material drawing method capable of reliably releasing the connection of the joint portion with a simple structure. For the purpose.
It is another object of the present invention to provide a structure of a joint portion of the core material in which the core material is not deformed at the joint portion during placement of the core material or in service.
Furthermore, it aims at providing the structure of the junction part of a core material which can be extracted with the minimum tensile force, and the core material extraction method. In particular, the structure of the joint part of the core material is not released when the core material is placed or when it is pulled up to adjust the position, and the connection of the joint material is released only when the core material is removed. The purpose is to do.
It is another object of the present invention to provide a structure of a joint portion of a core material in which only the core material can be pulled out and mortar, earth and sand, or soil cement around the core material is less likely to come out together with the core material .
The present invention achieves at least one of these objects.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the structure of the joint portion of the core material of the present invention is a structure of the joint portion of the core material that joins the core materials of long objects to each other, and has two cores. An outer shell member surrounding the outer periphery of the butting portion of the material, a joining means for joining the outer shell member and one of the core members, and a connecting member attached across the butting portion, the outer shell member, It is a structure in which the core member is contracted after being placed in the butted portion and is in close contact with the core material, and when a tensile force equal to or greater than a predetermined tensile force is applied to one of the core materials, the connecting member is near the butted portion. It breaks and the core material which faced | matched isolate | separates.
In addition, when a fracture bolt that joins the outer shell member and the other core material in place of or in combination with the connecting member is used, and a tensile force greater than a predetermined tensile force is applied to either one of the core materials In addition, it is also possible to configure so that the rupture bolt breaks and the core material butted is separated.
Moreover, one core material and the said outer shell member can also be joined with a temporary bolt.
[0007]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Embodiment 1 of the present invention will be described below with reference to the drawings.
[0008]
<A> Core Material The core material 1 used in the present invention is made of H-shaped steel, groove-shaped steel, angle steel, steel pipe, steel sheet pile, or the like having an arbitrary length. The core material 1 is placed in the ground as a support member such as a lining plate or a pile, or a core material of a soil cement underground wall.
The core material 1 used in the present invention is divided into two parts with a butt portion 11 as a boundary. The two core materials 1a and 1b may be butted together at the butting portion 11, or the core materials 1a and 1b obtained by cutting the one core material 1 into two parts may be used. The butting portion 11 is a portion where the end faces of the core materials 1a and 1b face each other, and is not joined. Further, the butting portion 11 is preferably in close contact, but may not be in complete contact, and may have a slight gap.
In the following description, the core material 1 on the drawing side will be described as the core material 1a, and the core material 1 on the side remaining in the ground will be described as the core material 1b.
[0009]
<B> Outer shell member The outer shell member 2 is a member arranged to reinforce the joint portion of the core material 1. The outer shell member 2 is disposed so as to surround the outer periphery of the butted portion 11 of the two core members 1a and 1b. For example, a box-shaped member penetrating in the vertical direction can be used as the outer shell member 2 (see FIG. 1).
Hereinafter, a method of attaching the outer shell member 2 will be described based on the embodiment shown in FIG.
FIG. 3A shows an embodiment in which the outer shell member 2 is manufactured using four plate members 21, 22, 22, and 22. First, the plate materials 21 and 21 are fixed to the flange side of the core material 1. The plate members 21 and 21 are fixed by known fastening means such as bolts 61 and vise 62. The plate members 21 and 21 attached to the flange side have a length that protrudes from the flange of the core member 1. And the board | plate materials 22 and 22 finished with the minus tolerance between the board | plate materials 21 and 21 are arrange | positioned. Since the plate members 22 and 22 are finished with a minus tolerance, a gap is generated between the plate members 21 and 21. However, the plate materials 22 and 22 are temporarily expanded by heat during the welding operation, and the plate materials 21 and 21 and the plate materials 22 and 22 can be joined.
When joined in this manner, the plate materials 22 and 22 contract after cooling and the plate materials 21 and 21 arranged on the flange side are firmly attached to the core material 1.
If the outer shell member 2 is arranged at the abutting portion 11 by applying a restraining force in this way, the reinforcing effect of the joining portion is increased, and the core material 1 is hardly deformed at the joining portion.
[0010]
The example shown in FIG. 3B is an embodiment in which the tightening direction is opposite to that in FIG. That is, it is a method in which the plate members 23 and 23 attached to the flange side are finished with a minus tolerance and joined to the web-side plate members 24 and 24. Also in this method, the thermal compression is finally generated, the outer shell member 2 is brought into close contact with the core material 1, and the joint portion can be restrained.
In the above description, the embodiment in which the plate members 22 and 23 are finished with a minus tolerance has been described. However, since the outer shell member 2 only needs to be brought into close contact with the joint portion of the core material 1, one of the plate members does not necessarily have a minus tolerance. It is not necessary to finish 22 and 23. For example, even when finished with accurate dimensions and plus tolerances, it may be possible to achieve close contact by thermal compression.
[0011]
<C> Connecting member The connecting member 3 is a member that connects the separated core members 1a and 1b. The connecting member 3 is a member that is not broken until a predetermined tensile force is reached, and is broken when a tensile force equal to or greater than a certain tensile force is applied.
The core material 1 may be subjected to a tensile force before being removed, for example, when it is transported before being placed, when it is built, or when the core material 1 that has been pushed too far is pulled up to match the ground 7. is assumed. For this reason, the connection member 3 is arrange | positioned so that between core material 1a, 1b may not isolate | separate by the tensile force which acts on the core material 1 before removal.
For example, a long plate material in which a constricted portion is disposed in the vicinity of the abutting portion 11 when attached to the core materials 1a and 1b can be used as the connecting member 3a (see FIG. 2). In the connecting member 3a, a constricted portion that is tapered near the end of the core material 1a on the drawing side is fixed by welding 31 so that the constricted portion is broken at the narrowest width, and the constricted portion is attached to the remaining core material 1b. Avoiding this, the vicinity of the end of the connecting member 3 a is fixed by welding 31. When a tensile force is applied to the core material 1a in this state, the constricted portion on the core material 1a side of the connecting member 3a is pulled up together with the core material 1a, and the constricted portion on the core material 1b side is not fixed by the welding 31. Easier to stretch than other parts, and when a predetermined tensile force is reached, the core material 1a and the constricted part are broken at the narrowest width.
In addition, although FIG. 2 demonstrated the connection member 3a which has the constriction part which a board | plate material tapers in the vicinity of the butt | matching part 11, and becomes a divergent part, it is not necessarily limited to this shape, A cutting | disconnection plan part is carried out by making a cut etc. It is also possible to apply known means for making the size smaller than other cross sections.
Further, a plate member having a uniform cross section without a constricted portion or a notch can be used as the connecting member 3. Even in this case, the welding 31 position of the connecting member 3 and the core material 1 can be adjusted as described above to be broken in the vicinity of the joint.
[0012]
The connecting member 3a shown in FIG. 2 is a member that extends along the core material 1a to the vicinity of the upper end of the core material 1a.
When the core member 1a is pulled out, the ground 7 is normally excavated until the lifting hole 12 is exposed. Therefore, if the upper end of the connecting member 3a is extended to the vicinity of the lifting hole 12, the connecting member 3a. The head can be easily exposed.
As a result, mortar and earth and sand that remain above the protruding cross section of the connecting member 3a can be eliminated, so that the pull-out load of the core material 1a is reduced and the amount of mortar and the like that rises together with the core material 1a is reduced. Can do.
In addition, when the mortar or the like is pulled out together with the core material 1a or the pulling load is slightly increased, the length of the connecting member 3a is set to a length that can be accommodated in the outer shell member 2. It is economical because it can be done.
[0013]
<D> Joining means The joining means 4 is means for joining the outer shell member 2 and one of the core members 1a and 1b.
When the outer shell member 2 is pulled out together with the core material 1a on the drawing side, the joining means 4 is used to join the core material 1a and the outer shell member 2 together.
Further, as described in the present embodiment, when the outer shell member 2 is left together with the remaining core material 1b, the joining means 4 is used for joining the core material 1b and the outer shell member 2.
As the joining means 4, for example, a fastening bracket such as a high-strength bolt or a hexagonal bolt or welding can be used. The bolt 61 used when arranging the outer shell member 2 can be used as it is as the joining means 4 without being removed.
It is preferable that the core material 1a on the side that is not joined to the outer shell member 2 by the joining means 4 is temporarily joined to the core material 1a and the outer shell member 2 by a fastener such as a temporary bolt 51. The bolt 61 used when arranging the outer shell member 2 can also be used as the temporary bolt 51.
[0014]
<E> Friction reducing means Friction reducing means can be applied to the core material 1a on the drawing side in order to reduce frictional resistance with mortar and the like.
For example, a known lubricant can be applied to the outer peripheral surface of the core material 1a before placing. Furthermore, a friction cut sheet having a smooth surface can be attached to the surface of the core material 1a.
[0015]
Hereinafter, the core material drawing method of the present invention will be described with reference to FIG.
[0016]
<I> Placing the core material (Fig. 4 (a))
Here, a case where the core material 1 is placed in a soil cement 71 constructed by stirring and mixing cement and ground will be described.
First, the ground is excavated to a predetermined depth with an earth drill or the like and stirred to form a soil cement 71 column in which earth and sand and cement are mixed.
Then, the core materials 1 a and 1 b joined by the temporary bolt 51 and the joining means 4 through the outer shell member 2 and connected by the connecting means 3 a are inserted into the soil cement 71. Usually, since the core material 1 is laid sideways, the head of the core material 1 is lifted with a wire, and is set in a vibratory hammer or the like for inserting the core material 1 into the ground and driven into the ground.
At this time, a tensile force, a lateral force, a bending force, a twisting force, and the like act on the joint, but the outer shell member 2 is disposed in close contact with the joint so as to surround the outer periphery of the butt 11. The core material 1 is not bent at the joint.
Moreover, since the outer shell member 2 and the core material 1a are joined by the temporary bolt 51 until the core material 1 is driven to a predetermined depth, the core materials 1a and 1b are not separated.
[0017]
<B> Removal of temporary bolts and resumption of placement (FIGS. 4B and 4C)
When the core materials 1a and 1b are buried to the vicinity of the butted portion 11, the driving is temporarily interrupted.
And the temporary bolt 51 which joins the core material 1a and the outer shell member 2 by the side of extraction is removed. If the core material 1 is embedded in the ground up to this depth, the temporary bolt 51 can be removed because a very large tensile force or the like is not applied to the joint.
Further, even if the temporary bolt 51 is removed, the core members 1a and 1b are connected by the connecting member 3a, so that the load is not separated if the load does not reach a predetermined tensile force.
After removing the temporary bolt 51, the placement of the core material 1 is resumed and buried to a predetermined position.
Here, the core material 1 may be driven too much and the head may be buried in the ground. In such a case, the position of the head is adjusted by slightly pulling out the core material 1, but even in this case, the core materials 1 a and 1 b are connected by the connecting member 3 a, so that they can be separated. Absent.
[0018]
<C> Pulling out the core material (FIG. 4D)
The core material 1 is pulled out after use. In this embodiment, only the upper core material 1a is pulled out.
First, the vicinity of the head portion of the core material 1a is excavated to expose the lifting holes 12 for anchoring the lifting wires and the head portions of the connecting members 3a.
Then, the wire is moored in the lifting hole 12 and pulled out with a crane or the like. The pull-out load depends on the breaking load at the planned breakage of the connecting member 3a, but it is preferable that the connecting member 3a be broken by a tensile force of about 10 t, for example. Further, it is preferable to reduce the pulling force of the crane as much as possible by using a pulley.
[0019]
Second Embodiment of the Invention
Next, an embodiment using a connecting member 3b different from the first embodiment will be described with reference to FIG. Here, since the configuration other than the connecting member 3b is the same as that of the first embodiment, the overlapping description is omitted.
[0020]
The connecting member 3b is a bar that breaks when a load equal to or greater than a predetermined tensile force is loaded. A small-sized bolt, a bolt with a cut, or the like can be used as the connecting member 3b.
First, the rib plate 32 is attached in the vicinity of the butt portion 11 of both core materials 1a and 1b to be connected. And the rib plate 32 attached to the core material 1a and the rib plate 32 attached to the core material 1b are connected by the connecting member 3b.
Although the structure of the connecting member 3b of the second embodiment may be more economical to manufacture than the structure of the connecting member 3a of the first embodiment, the rib plate 32 provides resistance when pulled out, and mortar and the like are shared. Since it may be up, it is applied according to the conditions. The connecting member 3a and the connecting member 3b can be used in combination.
[0021]
Embodiment 3 of the Invention
In the third embodiment, an embodiment using the breaking bolt 8 will be described with reference to FIG. Here, since the configuration other than the breaking bolt 8 is the same as that of the other embodiments, the overlapping description is omitted.
[0022]
The breaking bolt 8 is a bolt that breaks when a shearing force resulting from a tensile force equal to or greater than a predetermined tensile force acts on the bolt. Small sized bolts, bolts with cuts, and the like can be used as the breaking bolts 8.
In the third embodiment, the breaking bolt 8 is used instead of the connecting member 3. Note that the breaking bolt 8 and the connecting member 3 can be used in combination.
The breaking bolt 8 is used as a bolt for joining the core material 1a and the outer shell member 2, for example. The temporary bolt 51 can be used as in the other embodiments. When a tensile force is applied to pull out the core material 1a, a shearing force is applied to the breaking bolt 8 and the bolt is broken.
As a result, the connection between the core material 1a and the core material 1b is released, and only the core material 1a can be pulled out.
[0023]
【The invention's effect】
Since the structure of the joint part of the core material and the method for extracting the core material of the present invention are as described above, the following effects can be obtained.
<A> A simple structure in which the butt portion of the core material is surrounded by an outer shell member and a tensile force equal to or less than a predetermined tensile force is dealt with by a connecting member or a breaking bolt. For this reason, the connection of a junction part can be cancelled | released reliably at the time of extraction.
<B> Since the outer shell member is disposed in close contact with the joint portion, the core material is not deformed at the joint portion during the placement or operation of the core material.
<C> Since the outer shell member has a structure in which the outer shell member is contracted after being arranged at the abutting portion and is brought into close contact with the core member, the reinforcing effect of the joint portion is also increased.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an embodiment of a core material drawing method according to the present invention.
FIG. 2 is a side view of an embodiment of the structure of the joint portion of the core material.
FIG. 3A is an explanatory diagram of an embodiment of an installation method of an outer shell member when a web side plate material is finished to a minus tolerance. (B) Explanatory drawing of the Example of the installation method of the outer shell member at the time of finishing a flange side board material to a minus tolerance.
FIG. 4 is an explanatory view showing the procedure of the core material drawing method of the present invention.
FIG. 5A is a side view of a second embodiment of the structure of the joint portion of the core material. (B) AA arrow directional view of figure (a).
FIG. 6 is a side view of a third embodiment of the structure of the joint portion of the core material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Core material 1a ... Core material 1b ... Core material 11 ... Butt part 2 ... Outer shell member 3 ... Connecting member 4 ... Joining means 51 ... Temporary bolt 8 ... Breaking bolt

Claims (3)

It is a structure of the joint part of the core material that joins the core materials of long objects to each other,
An outer shell member surrounding the outer periphery of the butt portion of the two core members;
A joining means for joining the outer shell member and one of the core members;
A connecting member attached across the abutting portion,
The outer shell member has a structure in which the outer shell member is contracted after being arranged in the butting portion and is in close contact with the core material,
When a tensile force greater than or equal to a predetermined tensile force is applied to one of the core materials, the connecting member breaks in the vicinity of the butt portion, and the butt core material is separated,
Structure of the core joint. It is a structure of the joint part of the core material that joins the core materials of long objects to each other,
An outer shell member surrounding the outer periphery of the butt portion of the two core members;
A joining means for joining the outer shell member and one of the core members;
The outer shell member and a breaking bolt for joining the other core material,
The outer shell member has a structure in which the outer shell member is contracted after being arranged in the butting portion and is in close contact with the core material,
When a tensile force equal to or higher than a predetermined tensile force is applied to either one of the core materials, the core material that is abutted by breaking the rupture bolt is separated,
Structure of the core joint. In the structure of the joint part of the core material according to claim 1 or 2 ,
One core material and the outer shell member are joined with a temporary bolt,
Structure of the core joint.

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