JPH0657944B2 - Crimping type post-fixing fixtures for prestressed concrete piles and pile head treatment method using post-fixing fixtures - Google Patents

Description

Detailed Description of the Invention

[Industrial applications]

TECHNICAL FIELD The present invention relates to a fixing tool for joining a pile head of a prestressed concrete pile and a reinforcing bar (anchor bolt) and a pile head treatment method using the fixing tool.

【Purpose】

The present invention is intended to obtain a highly earthquake-resistant pile head joint structure in a prestressed concrete pile foundation structure for construction and civil engineering, and can be easily retrofitted to a normal prestressed concrete pile without changing its structure, and An object of the present invention is to provide a crimping type post-fixing fixture that can secure a connection performance equivalent to the durability performance of a PC steel rod and a pile head treatment method using the fixing fixture.

[Prior art]

The prestressed concrete pile is a type of pile in which a high bending strength is generated by combining a high-strength concrete and a high-strength PC steel rod and introducing prestress by tensioning the PC steel rod. In the foundation method using this pile type, a high-strength and high-quality pile body part is formed by factory manufacturing, but in the earthquake resistance of the pile head joint, the pile end structure and the reinforcing bar (anchor bolt) that rebars the foundation slab. Since it has not been manufactured in consideration of joining, the connection metal fittings have not been developed, and the current situation is that the connection structure and connection construction have not been adequately dealt with. Conventionally, the following have been disclosed as a pile head processing method and a fixing tool for obtaining a pile head joint having a slightly high earthquake resistance. Method of embedding female screw coupler in pile head and forming fixing hole of superstructure connection reinforcing bar Method of simply fixing reinforcing bar having male screw part in female screw hole provided on end plate (Japanese Patent Publication No. 53-40802) Synthetic resin molding With a connector of the product, a taper is formed in the lower part, it fits into the tapered hole of the dish part, and a female screw is drilled in the upper part of the connector, and this female screw is screwed to the tip of the vertical bar of the reinforcing bar. Japanese Patent Laid-Open No. 58-54449 discloses a structure in which a male screw is screwed and connected and fixed. The nut is screwed into the PC steel rod 3 to fix the foundation, and the tip of the PC steel rod 3 is projected from the nut.
Next, a coupler is screwed into the tip of the protruding PC steel rod 3 and a half of the PC steel rod 4 penetrating the cushion ring base from the opposite side of the coupler.
A configuration for connecting with the C steel rod 4 is disclosed (Actually, Shokai 4
9-126395).

[Problems to be solved]

However, the above conventional technique has the following problems. The former requires the improvement of the manufacturing process of piles, the reduction of manufacturing efficiency, structural imperfections, and the situation where pile heads are cut off (cutoff) when the construction of piles is not performed accurately. There was a problem that it was wasted. On the other hand, in the latter, the thickness of the end plate for fixing the reinforcing bar is usually 9 mm ~
Since the internal thread of the pile head end plate is as thin as about 19 mm and it is an incomplete bolt hole having a “gourd-shaped” defect, there is a problem that the fixing performance required for strength cannot be secured. For example, the internal thread of the pile head end plate is made of mild steel, so it may be damaged and the strength may be reduced during construction.If the connecting rebar is simply connected, the fixing force of the joint will reach the specified strength. It is not possible to confirm whether or not it is. In order to use an incomplete bolt hole having a defective portion as a bolt hole of a permanent structure, it is necessary to confirm and guarantee the strength. Further, in the above-mentioned publicly disclosed technique, the connection with the dish portion is made by loading the taper hole, and the connection with the lower PC steel bar has no structure. The disclosed technology is to vertically connect an upper PC steel bar and a lower PC steel bar. The tip of the lower PC steel rod penetrates the nut, and the nut is merely a connection fitting and cannot apply downward contact pressure to the PC steel rod. Also, since there is no male screw structure, there is no fixing force to the pile head end plate.

[Means for solving problems]

The present invention solves the above-mentioned problems by developing a post-fixing fixing device of a crimping type that is attached to a pile head end plate. [Structure of anchoring device] The anchoring device is to be screwed into the pile head end plate of the prestressed concrete pile and to connect the connecting reinforcing bar (anchor bolt) of the foundation slab to this, and the female screw fixing hole into which the connecting reinforcing bar is screwed Is provided on the upper surface, and a head is provided on the lower surface, which has a crimp fixing portion for crimping to the end of the PC steel rod and a bearing fixing portion for supporting the upper surface of the pile head end plate, A male screw that is screwed into the female screw hole of the pile head end plate is formed. In the fixing tool, the male screw of the fixing tool is inserted and screwed into the female screw hole provided near the PC steel rod fixing portion of the pile head end plate, and then the head of the fixing tool (because it is tightened with a wrench etc. The outer periphery is preferably a nut shape such as a hexagon), and is crimped, and the PC steel rod end is moved through the pile head end plate in a direction opposite to the pushing direction of the crimp fixing part (arrow 12 in the figure). A contact pressure is generated between the rod end and the crimp fixing part to fix it to the pile head end plate. Further, in the tightening of the fixing tool by screwing, a fixing force equal to or higher than the tensile strength of the connecting rebar (anchor bolt) to be fixed to the pile later is generated by tightening the head with a predetermined torque or the like. Then, by firmly tightening the fixing tool, a contact pressure is generated between the pile head end plate and the fixing tool. The fixing device of the present invention is designed to be strongly screwed in advance and the lower surface thereof is crimped to the end portion of the PC steel rod and the upper surface of the end plate, and the connecting reinforcing bar can be easily connected to the pile. [Construction of pile head treatment method] In the pile head treatment method using the fixing tool, the male screw of the fixing tool is formed in a female screw hole provided in the pile head end plate of the prestressed concrete pile near the fixing portion of the PC steel rod. By screwing by tightening the head, a fixing force greater than the tensile strength of the connecting reinforcing bar is generated, and a contact pressure is generated between the crimping fixing portion and the end of the PC steel rod to fix it to the pile head end plate, and then the fixing tool. It is characterized in that a connecting reinforcing bar is connected to and the connecting reinforcing bar is used as a connecting bar between the foundation slab and the pile. This process is a pile head treatment method that integrates the foundation slab and prestressed concrete pile. After this, concrete is placed and the foundation is constructed. This method does not require the crushing of pile heads,
It is possible to provide a structure in which the C steel rod and the connecting rebar have a linear and rigid connection structure and excellent earthquake resistance.

【Example】

Here, an embodiment of the fixing tool of the present invention and a construction method using the fixing tool will be specifically described with reference to the drawings. [Fixing Tool] The fixing tool 20 connects the pile head end plate 9 of the prestressed concrete pile and the connecting reinforcing bar (anchor bolt) 1 of the foundation slab, and the female screw fixing hole 2 of the connecting reinforcing bar 1 is provided on the upper surface. It has a head portion 6 provided with a reinforcing bar fixing portion 3, a crimp fixing portion 4 for crimping the end of the PC steel rod 10 on the lower surface, and a bearing pressure fixing portion 5 for generating bearing pressure on the upper surface of the pile head end plate 9. A male screw 7 is formed on the lower surface thereof. The shape of the fixing device 20 shown is a shape in which a thin short tube portion is formed in the upper portion and the lower portion is expanded in a cone shape. Since the fixing tool 20 has its head 6 tightened with a wrench or the like, the outer shape of the head 6 is molded into a shape that is easy to tighten. This fixing tool 20 has a male screw 7 below a female screw hole 8 provided in the pile head end plate 9 in the vicinity of the end (fixing portion) 11 of the PC steel rod 10.
Screw in and then tighten the head 6 to tighten the pile head end plate 9
Then, the PC steel rod end 11 is moved in the direction opposite to the propelling direction of the crimp fixing part 4 (arrow 12 in the figure), and the PC steel rod end 11 and the crimp fixing part 4 are crimped and attached. In this fixing state, an upward acting force 12 is exerted on the end portion 11 of the PC steel rod 10 and a downward resistance force 13 is exerted on the crimp fixing portion 4.
Is occurring. That is, contact pressure is generated. In this fixing tool 20, the connection reinforcing bar 1 is fixed by screwing to the female screw fixing hole 2 in the reinforcing bar fixing section 3, but the structural integrity of the reinforcing bar fixing section 3 and the crimp fixing section 4 is determined by the fixing tool 20. Head 6
Is secured by the strength and rigidity possessed as a support structure connected to the PC steel rod 10. The fixing tool 20 is attached to the pile head end plate 9 with a strong fixing force so as to press the PC steel rod end 11 in advance at a factory or the like. An appropriate number of fixing tools 20 are attached according to the size of the annular pile head end plate 9 and the number of PC steel rods. The fixing tool 20 proposed by the present invention is used in advance in a factory or the like in order to remove the pile head end plate 9
Since the connecting rebar 1 is attached to the prestressed concrete pile afterwards, it is referred to as a crimp type post-fixing fixture. The pile head end plate 9 is an annular plate made of metal and provided with a PC steel rod fixing portion which is a conical insertion hole for exposing the end portion 11 of the PC steel rod 10 on the upper surface, and penetrates through this. An appropriate number of PC steel rods 10 are stretched, and an appropriate number of female screw holes 8 are provided near the PC steel rod end portion 11.
Is provided. In the fixing tool 20, the male screw 7 is screwed into the female screw hole 8 of the pile head end plate 9, and, for example, the PC steel rod end portions 11 located on the left and right are crimped by the fixing fixing portion 4 as shown in FIG. The upper surface of the pile head end plate 9 is supported by the support pressure fixing portion 5 at a position located at. Unlike FIG. 2, FIG. 3 is a crimp type post-fixing fixture for fixing one connecting rebar 1 to one PC steel rod 10.
FIG. 20 is a cross-sectional view showing a state where 20 is crimped to the pile end portion. This fixing tool 20 has an end portion of the PC steel rod 10 on one side of the male screw portion 7.
The crimp fixing part 4 for crimping 11 is provided, and the pressure supporting part 5 for generating and resisting the supporting pressure on the pile head end plate 9 against the bending moment generated by this contact pressure is used as the crimp fixing part 4.
It is formed on the lower surface of the head portion 6 on the opposite side. Since the crimp fixing portion 4 and the bearing supporting portion 5 are in pressure contact with the pile head end plate 9, even if a lateral load is applied to the connecting rebar 1 which is connected and erected, due to the contact pressure, 7 parts of the male screw of the fixing tool 20 are attached. It has a structure that can reduce the direct load on. The PC steel rod 10 of the prestressed concrete pile connected using the fixing tool 20 and the connecting rebar 1 are linearly connected. [Pile head treatment method] In the pile head treatment method using the fixing tool 20, the fixing tool 20 is fixed to the pile head end plate 9 of the prestressed concrete pile, and then the connecting rebar 1 is fixed to the fixing tool 20. This is a pile head treatment method using a retrofitting fixing tool, characterized in that the reinforcing bar 1 is used as a connecting bar between a foundation slab and a pile. Explaining in detail in the order of construction work, A: In a factory or the like, the fixing tool 20 is preliminarily attached to the pile head end plate 9 of the prestressed concrete pile so that the lower surface thereof is crimped to the PC steel rod end portion 11 and bears against the upper surface of the end plate 9. Install. As a work procedure, the mounting position of the fixing tool 20 is marked on the pile head end plate 9, the female screw hole of the pile head end plate 9 is cleaned, and the fixing tool 20 is temporarily tightened. Then tighten the book. After that, as before, the prestressed concrete pile is carried into the site, sunk, and after sunk, root cutting is performed so that the fixing tool 20 is not damaged, and concrete is placed on the root cutting bottom. B: Attach the connection bar (anchor bolt) 1 of the base slab to the female screw 2 on the upper surface of the fixing tool 20 and plant it. This is the pile head treatment method that integrates the connecting bar of the foundation slab and the prestressed concrete pile by the process of. . After this, concrete is poured and the foundation is constructed. This construction method can provide a structure in which the connection structure of the PC steel rod and the connecting rebar is linear and strong and has excellent earthquake resistance, as well as the need for crushing the pile head (cutoff). Note that these examples are merely examples, and the idea of the present invention is not limited to these.

【The invention's effect】

"Crimping type post-fixing fixture for prestressed concrete pile and pile head treatment method by post-fixing fixture" according to the present invention,
The above-mentioned configuration and operation have the following unique technical effects. ◇ The fixing tool with the required fixing performance can be fixed to the pile head end by the tightening condition (torque and rotation angle adjustment) applied to the head of the fixing tool. ◇ Since the PC steel rod and the connecting rebar are directly connected through the fixing tool, a highly earthquake-resistant pile head joint structure with an efficient stress transmission mechanism is formed. ◇ Since it protrudes high on the pile head end plate of the fixing tool, it is easy to remove and clean the mud and soil cement adhering to the fixing tool when the pile is sunk. ◇ Concerning the pile construction results, construction can be performed after ensuring that pile head processing by retrofitting is possible, so there is no waste and no waste. ◇ No decrease in strength and no antibody damage due to reduction in prestress amount due to crushing (cutoff). ◇ It can be applied as is to conventional prestressed concrete piles with end structures. ◇ The structure (economically) can be manufactured at a low cost, and the pile head crushing treatment cost and the filling work cost for filling in the middle due to crushing are unnecessary. ◇ Pile head crushing work is not required, and special work techniques are not required, which shortens the construction period and meets site requirements. ◇ The fixing tool is pressed against the pile head end plate by a downward force, and the male screw is screwed into the steel plate to give a vertical force to the PC steel bar due to the contact pressure and to the upper end of the PC steel bar in the downward direction. Since force is applied, firm fixation can be achieved. As described above, the present invention, in the joining technology of the pile head and the foundation slab, can improve the joining performance and safety, and should be a valuable and excellent invention that provides great utility to the pile head treatment method. .

[Brief description of drawings]

The drawings show an embodiment of a fixing tool of "crimp type post-fixing fixture for prestressed concrete pile and pile head treatment method using post-fixing fixture" according to the present invention, and FIG. 1 is a plan view of the fixing fixture of the present invention. FIG. 2 is a sectional view of a state in which the fixing tool is attached to the pile head end plate. FIG. 3 is a cross-sectional view showing another embodiment of the fixing tool, in which a fixing tool of a type for fixing one connecting rebar to one PC steel rod is crimped to the pile head end plate. . Short description of the code 1 …… Connecting rebar 20 …… Fixing tool 2 …… Female thread fixing hole of connecting rebar 3 …… Reinforcing bar fixing section of fixing tool 4 …… Crimping fixing section of fixing tool for crimping to PC steel rod end 5 …… Fixing tool bearing pressure fixing part 6 …… Fixing tool head 7 …… Fixing tool male screw part 8 …… Female screw hole provided in pile head end plate 9 …… Pile head end plate 10 …… PC steel Rod 11 …… PC steel rod end 12 …… Upward acting force generated at the PC steel rod end in the crimped state 13 …… Downward resistance force generated at the crimp fixed part in the crimped state

Claims (2)

[Claims] 1. A prestressed concrete pile for connecting a reinforcing bar 1 of a foundation slab, wherein a prestressed concrete pile head and an end of a PC steel rod 10 are connected.
11 is penetrated to the fixing portion of the PC steel rod and the end portion of the PC steel rod is
Providing a pile head end plate 9 provided with a female screw hole 8 in the vicinity of 11, and as a fixing tool for connecting the connecting rebar 1 to the pile head end plate 9,
Reinforcing bar fixing part 3 provided with female screw fixing hole 2 of connecting reinforcing bar 1 on the upper surface, crimp fixing part 4 for crimping to PC steel rod end part 11 on the lower surface, and bearing pressure fixing part for generating bearing pressure on the pile head end plate 9. A crimping type post-fixing fixture for a prestressed concrete pile, comprising a head 6 provided with 5 and further having a male screw 7 screwed into the female screw hole 8 of the pile head end plate 9 on the lower surface. 2. Reinforcing bar fixing part 3 having female screw fixing hole 2 of connecting reinforcing bar 1 on the upper surface, crimp fixing part 4 for crimping to PC steel rod end 11 of pile head end plate 9 on the lower surface, and said pile head end plate. 9 has a head portion 6 provided with a bearing fixing portion 5 for bearing a pressure and a male screw 7 of a fixing tool 20 having a male screw 7 on the lower surface thereof is used to fix a PC steel rod fixing portion of a pile head end plate 9 of a prestressed concrete pile. 3 is screwed into the female screw hole 8 provided in the vicinity of 3 by tightening the head of the fixing tool to generate a fixing force equal to or higher than the tensile strength of the connecting rebar 1, and the crimp fixing part 4 is directed downward with respect to the PC steel rod end 11. While the resistance force is being generated, the male screw 7 is screwed in to generate an upward acting force on the PC steel rod end 11 to fix it to the pile head end plate 9, after which the connecting rebar 1 is connected to the fixing tool 20 and this connection is made. Reinforcing bar 1 is used as a connecting bar between the foundation slab and the prestressed concrete pile. Pile processing method by the fixing device with after that.