JP2009228313A - Connecting material for pile head joint, and pile head joint structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting material for a pile head joint, which dispenses with welding operations on a job site and drilling operations around a pile head section, which can improve an operation of attachment to a steel pipe pile without decreasing a coupling force between the steel pipe pile and a structure, and which can be applied to the pile head section cut due to the difficulty of the further driving of the pile. <P>SOLUTION: In this connecting material 20 for the pile head joint, an upper end of a steel pipe body 21 with a required length and an outside diameter slightly smaller than an inside diameter of the steel pipe pile 5 is equipped with an anchoring portion 24 which is composed of a circular steel plate with a diameter larger than the outside diameter; and each of a central portion and a lower end is equipped with a sealing portion 23 which is composed of a flange-formed portion 22 and a circular steel plate. The connecting material 20 inserted from above the steel pipe pile 5 is locked in a prescribed position by making the flange-formed portion 22 abut on the upper end surface of the steel pipe pile 5. A grout material 6, which is infilled in a gap between the connecting material 20 and the inner peripheral surface of the steel pipe pile 5 from an injection hole provided in the flange-formed portion 22, is solidified so that the connecting material 20 can be firmly fixed to the pile head section of the steel pipe pile 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connecting material used for joining a pile head of a steel pipe pile and a foundation concrete in which the pile head of the steel pipe pile is buried inside a footing concrete, and a pile head joining structure to which this connecting material is applied. Is.

  Regarding the installation of steel pipe piles in the construction of various civil engineering structures, the foundation of the pile is connected to the pile head by connecting reinforcing bars such as deformed bars and threaded joints to the footing concrete on the structure side. The method of joining a pile and a structure is generally performed widely. This type of pile head rebar connection method includes welding the lower end of the pile head rebar directly to the outer periphery of the pile head, or threaded joints via a coupler welded to the outer periphery of the pile head. There are widely known ones in which a deformed rebar with a threaded end is screwed. However, when welding a pile head reinforcement or a coupler for connecting it to an upright state on the pile head of a steel pipe pile embedded in the ground, the working environment is limited. Moreover, since it is a troublesome welding work along each pile head rebar or coupler, it is difficult to shorten the work time, and it is also affected by the weather, and the welding quality tends to become unstable. There were not a few problems above. On the other hand, when the welding work is performed in advance in a place other than the site such as a factory, when the steel pipe pile is driven, the pile head rebar or coupler welded to the end of the steel pipe pile interferes with the driving work. It is easy to lead to decline. In addition, when the steel pipe pile hits hard ground or rocks during driving and it becomes difficult to drive further (high stop), an extra part so that the protruding length from the ground surface will be the predetermined length After cutting out, there was a problem that there was a case where the reinforcing bars and couplers had to be re-welded to the pile head.

Then, various methods other than welding are proposed as a connection method to the steel pipe pile of the pile head reinforcement which joins a steel pipe pile and foundation concrete. For example, there is one in which a pile head hardware formed by welding a plurality of pile head rebars in a standing state on the outer periphery of a cylindrical lid body whose upper end is closed is put on the head of a steel pipe pile from above (Patent Document 1). . In addition, the outer steel pipe is covered on the outer side of the pile head, and a plurality of pile head reinforcing bars are arranged at predetermined intervals along the inner peripheral surface of the outer steel pipe, and then the concrete is filled in the outer steel pipe to thereby make the pile head There is also what fixes a reinforcing bar (patent document 2). Furthermore, a cylindrical steel ring with an inner diameter slightly larger than that of the steel pipe pile, or a pile head reinforcing member formed by welding a plurality of pile head rebars to the outer peripheral surface of the outer steel pipe is externally fitted to the pile head. There has also been proposed a method of joining pile head reinforcing bars by filling mortar or the like in the gaps (Patent Documents 3 and 4). However, in the non-weld type pile head rebar connection technology described in Patent Documents 1 to 4, all of the soil around the pile head must be excavated greatly when connecting the steel pipe pile to the pile head. There was a problem.
JP-A-11-280063 JP 2004-162455 A JP 2005-105812 A JP 2005-139731 A

  The present invention has been made in view of the state of the prior art as described above, and does not require welding work at the construction site and excavation work around the pile head, and the coupling force between the steel pipe pile and the structure is low. A connection material for pile head joining that is stable, can be easily attached to the steel pipe pile, and can be applied to a pile head cut by a high-stop, and a steel pipe pile using this The purpose is to provide a joint structure with foundation concrete.

In order to solve the above-mentioned problems of the prior art, the invention according to claim 1 of the present application extends upward from the pile head of a steel pipe pile placed in the ground, and is embedded in the foundation concrete above the pile head. A connecting member for connecting a pile head and foundation concrete, wherein the lower end side is loosely inserted into the pile head of the steel pipe pile and a non-insertion portion is provided with a fixing portion for the foundation concrete. Therefore, the steel pipe pile is fixed to the steel pipe pile by a grout material filled in a gap between the inner peripheral surface of the pile head and the steel pipe pile facing the outer peripheral surface in the insertion portion.

  Furthermore, in the connecting member for pile head connection according to claim 1 described above, the fixing portion of the steel pipe body is an enlarged diameter portion protruding outward in the radial direction from the outer peripheral surface (claim 2) or a pipe wall. The structure (Claim 3) made into the several through-hole penetrated is employable. Furthermore, the structure which provided the hook-shaped part which contact | abuts the pile head end surface of a steel pipe pile in the boundary of the insertion part of the said steel pipe body and a non-insertion part (Claim 4), In the lower end part of the said steel pipe body, It is also possible to adopt a configuration (Claim 5) in which a sealing portion that closes the entire circumference of the gap with the inner peripheral surface of the pile head facing the outer peripheral surface on the lower end side is provided. Moreover, the invention which concerns on Claim 6 of this application is the pile head junction structure using the connection material for pile head joining as described in any one of the said Claim 1 thru | or 5.

In the connection material for pile head joining which concerns on this invention, and the pile head joining structure using this, the following effect can be acquired by employ | adopting the above structures.
(1) Since a steel pipe body is used as a connecting material for pile head joining, and this is inserted into the pile head of the steel pipe pile, it is fixed via a grout material filled between both peripheral surfaces. No welding work or excavation work around the pile head is required, and the connection work of the connecting material for pile head joining to the pile head is extremely simple.
(2) The mounting work of the connecting material for pile head connection to the steel pipe pile is performed by filling the grout material, so it is less affected by the weather in the field compared to the conventional welding method, and quality is not required by skilled workers. A stable connection state can be obtained.
(3) The grout material filled in the gap between the pile head inner peripheral surface of the steel pipe pile and the outer peripheral surface of the steel pipe body, which is the pile head joint connecting material, is inserted into the pipe head joint connecting portion. Since it is in a state of being constrained between the walls, its strength increases due to the mutual constraining effect (confined effect), and a strong coupling state of the connecting material is obtained with respect to the pile head of the steel pipe pile. The connection strength of the connecting material for the pile head connection to the pile head of is increased.
(4) Since the connecting material for connecting the pile heads can be installed at a desired position from the upper end surface side of the pile head after installation of the steel pipe pile without any processing on the pile head of the steel pipe pile, Even when the pile head is cut due to the high stop, it can be applied without hindrance and does not get in the way when the steel pipe pile is driven.
(5) When a saddle-like part that can contact the pile head end face of the steel pipe pile is provided at the boundary between the insertion part and non-insertion part of the steel pipe body, a compressive force is applied to the saddle-like part from above. Since the lower grout material is also restrained from the upper surface, the connection strength between the pile head joint and the pile head of the steel pipe pile is further increased. Furthermore, the presence of the hook-shaped portion is advantageous in terms of construction because it can easily determine the protruding length of the connecting material for pile head bonding with respect to the pile head and can reliably hold the insertion state.
(6) When a sealing portion capable of sealing the entire circumference of the gap between the lower end portion of the steel pipe body and the inner peripheral surface of the pile head facing the outer peripheral surface on the lower end side in the insertion portion is provided, the grout material Leakage downwards can be reliably prevented during filling.

  As described above, the connecting material for pile head joining according to the present invention is composed of a steel pipe body provided with a fixing portion for foundation concrete such as an enlarged diameter portion or a through hole at a pipe wall or an end portion, and a lower end side of the steel pipe pile. Easy installation of the pile head at the construction site by adopting a structure that is fixed upright with respect to the steel pipe pile with the grout material filled in the gap between the two in the state of loose insertion in the head At the same time, it has a great feature in that a stable connection state is realized. That is, when attaching the connecting material for pile head connection, no processing is required on the pile head of the steel pipe pile, and it can be easily and reliably installed even by an unskilled person. It greatly contributes to the rationalization of work. In particular, in the installation work of the steel pipe pile, there is an advantage that the connecting material for pile head joining can be applied as it is even when the pile head is cut by a high stop. Further, the material of the grout material used in the present invention is not particularly limited, but specifically, cement milk, mortar, synthetic resin, and the like are preferable. Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is of course not limited to these embodiments, and within the technical idea of the present invention, such as changes in the material, shape, quantity, and position of each component. Of course, various modifications can be made.

  FIG. 1 is a cross-sectional view illustrating a first embodiment of a connecting member for pile head bonding according to the present invention and showing a use state thereof. In the illustrated pile head joint 1, a steel disc 3 having an outer diameter somewhat larger than the outer diameter is fixed to the upper end of a steel pipe body 2 having a required length and outer diameter by welding or the like. While functioning as a fixing portion (expanded diameter portion), the lower end side of the steel pipe body 2 is opened as it is. Such a pile-head-joining connecting material 1 is inserted into the pile head of the steel pipe pile 5 projecting on the surface of the ground 4 with its lower end portion being loosely fitted by a predetermined length, It is integrated with the steel pipe pile 5 by being fixed via the grout material 6 filled in the gap formed therebetween. When filling the grout material 6, an appropriate closing material (not shown) may be packed in the lower end side portion of the gap in order to prevent the downward flow.

FIG. 2 is an explanatory view schematically showing a stress transmission mechanism in a pile head joint structure using the connecting member 1 for pile head joint. In other words, the pile head of the steel pipe pile 5 and the connecting member 1 for connecting the pile head protruding upward are embedded in the footing 7 constituting the foundation concrete. A vertical load (axial force) N from the upper structure loaded on the footing 7 is transmitted to the steel disc 3 on the upper end surface of the steel pipe 2 and further solidified grout material on the lower end side of the steel pipe 2. 6 is transmitted to the steel pipe pile 5 through frictional force on the inner and outer surfaces. Further, the pulling load generated from the upper structure is transmitted from the steel pipe body 2 to the steel pipe pile 5 via the grout material 6 by the fixing portion 3 (steel disk). In the pile head joint structure according to the present invention, with respect to the bending moment M from the footing 7 to the pile head of the steel pipe pile 5 at the time of an earthquake, a large compressive force is exerted on the grout by the repulsive action as the steel pipe body 2 is inclined. However, since the grout is constrained by the steel pipe pile 5 and the steel pipe body 12, the compressive strength is greatly improved, and the joint strength between the steel pipe pile 5 and the connecting material 1 for pile head joining is further increased.

3 and 4 are a partial cross-sectional view showing a use state of a pile head joint connection material according to a second embodiment of the present invention, and a cross-sectional view taken along line AA of the pile head joint connection material. Note that the description of the same parts as in the above embodiment is omitted. In the illustrated connecting member 10 for pile head bonding, six through holes 12 are provided at the same height position at equal intervals in the upper end side portion of the steel pipe body 11. The through-hole 12 is not limited to a circular shape, and various shapes can be adopted. In this case, when the pile heads of the steel pipe piles 5 are embedded in the footing, the through holes 12 are substantially fixed by being integrated in a state where the concrete is filled in the through holes 12. Will function as. Although not shown, when the pile head connection material 10 is embedded in the footing, a bottom plate or the like is provided in the steel pipe body 11 so that excess concrete is not filled in the steel pipe pile 5. It is possible to save the amount of concrete during construction. In addition, a fixing function can be obtained by forming a plurality of circumferentially extending grooves or protrusions on the outer peripheral surface of the steel pipe body 11 in place of the through holes 12, but the through holes are advantageous in terms of cost. At the same time, it leads to weight reduction of the connecting material for pile head joining.

FIG. 5: is sectional drawing which shows the use condition of the coupling material for pile head joining which concerns on 3rd Example of this invention. In the connecting member 20 for pile head joining shown in the figure, the fixing portion 24 on the upper end surface of the steel pipe body 21 is the same as that of the first embodiment, but the hook-like portion 22 is integrally formed in the middle portion of the steel pipe body 21. Furthermore, it is the structure which provided the sealing part 23 in the lower end side. In this case, the bowl-shaped portion 22 is fixed to the outer peripheral surface at the substantially center in the axial direction of the steel pipe body 21 by welding or the like. The position of the hook-like portion 22 is set at the boundary between the insertion portion with respect to the steel pipe pile 5 and the non-insertion portion above the insertion portion. That is, the fixing unit 24 functions as a fixing unit for the foundation concrete 7. Therefore, the length of the non-insertion portion of the steel pipe body 21 needs to be long enough to prevent the foundation concrete 7 from having a cone-like fixing failure. Further, the length of the insertion portion needs to be a length capable of transmitting stress to the steel pipe pile 5 through the grout material 6 with respect to the tensile force and supporting pressure acting on the steel pipe body 21.

In the said Example, the saddle-like part 22 has the effect which receives the vertical load of the building concerning the steel pipe pile 5, and when compared with the case where a vertical load is received only at the end surface of a normal steel pipe pile, the bearing stress of foundation concrete To prevent crushing of pile upper foundation concrete. Moreover, the hook-shaped part 22 is utilized also as a positioning means by contact | abutting to the end surface of the steel pipe pile 5 in the case of construction. Furthermore, the vertical load has an effect of pressing down the bowl-shaped portion 22 and pressing the grout material 6 filled in the gap between the outer peripheral surface of the steel pipe body 21 and the inner peripheral surface of the steel pipe pile 5 on the upper surface side. For this reason, the grouting material 6 which receives compressive stress due to the bending effect of the bending resistance of the steel pipe body 21 is restrained from above by the ridge-shaped portion 22, and the compression proof stress of the grouting material 6 is increased to make a stronger grouting joint. Can do. Note that the bowl-shaped portion 22 is provided with a small hole for injecting the grout material 6 from above. The sealing portion 23 is formed by concentrically fixing a steel disk having a diameter substantially close to the inner diameter of the steel pipe pile 5 to the lower end surface of the steel pipe body 21. Block outflow. The fixing portion 24 on the upper end surface of the steel pipe body 21 is the same as that in the first embodiment.

  FIG. 6 is an explanatory diagram of the stress transmission mechanism in the pile head joint structure using the pile head joint material 20 according to the third embodiment. In this case, the compressive stress due to the axial force N from the footing 7 is transmitted to the fixing portion 24 as in the first embodiment, but is also transmitted to the flange-shaped portion 22 protruding outward in the radial direction of the steel pipe body 21. As a result, by constraining the grout material 6 filled on the lower surface side from the upper surface side in addition to the restraining effect in the radial direction, the proof strength of the grout material 6 is further increased, and a strong pile head joint state is obtained. It is done.

  FIG. 7 thru | or FIG. 9 is a partial sectional view which is a modification of the connection material 20 for pile head joining which concerns on the said 3rd Example provided with a hook-shaped part and a sealing part, and shows a use condition. The pile head connecting material 30 in FIG. 7 uses a diameter-expanded portion, which is a trumpet-shaped outer end portion of the steel pipe body 31, as the fixing portion 32. The pile-head-joining connecting member 40 in FIG. 8 has a long hole-like through hole 42 provided in the upper part of the steel pipe body 41 as a fixing portion. The pile-head-joining connecting member 50 shown in FIG. 9 has a further improved fixing strength by attaching a deformed reinforcing bar 52 to the outer peripheral surface of the steel pipe body 51. In addition, in the connection material for pile head joining that uses the through hole in the upper part of the steel pipe body as a fixing part as shown in FIG. 3, FIG. 8, and FIG. 9, the through hole should be used for applications that do not stop at the concrete distribution hole. You can also. That is, when the reinforcing bar is inserted so as to penetrate the steel pipe body in the horizontal direction, the fixing strength of the through hole can be further improved.

It is sectional drawing which shows the use condition of the coupling material for pile head joining which concerns on 1st Example of this invention. It is explanatory drawing which showed typically the stress transmission mechanism in the pile head joining structure using the connection material for pile head joining of FIG. It is a fragmentary sectional view which shows the use condition of the connection material for pile head joining which concerns on 2nd Example of this invention. FIG. 4 is a cross-sectional view taken along line AA in the second embodiment of FIG. 3. It is sectional drawing which shows the use condition of the coupling material for pile head joining which concerns on 3rd Example of this invention. It is explanatory drawing which showed typically the stress transmission mechanism in the pile head joining structure using the connection material for pile head joining of FIG. It is a fragmentary sectional view showing the modification of the connection material for pile head joining concerning the 3rd example. It is a fragmentary sectional view showing the modification of the connection material for pile head joining concerning the 3rd example. It is a fragmentary sectional view showing the modification of the connection material for pile head joining concerning the 3rd example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10,20,30,40,50 ... Connection material for pile head joining, 2, 11, 21, 31, 41, 51 ... Steel pipe body, 3, 12, 24, 32, 42 ... Fixing part, 4 ... Ground 5 ... steel pipe pile, 6 ... grout material, 7 ... footing, 22 ... bowl-shaped part, 23 ... sealing part, 52 ... rebar

Claims (6)

A pile head joint connecting material that extends upward from the pile head of a steel pipe pile placed in the ground, is buried in the foundation concrete above the pile head, and joins the pile head and the foundation concrete, It consists of a steel pipe body with a lower end side loosely inserted into the pile head of the steel pipe pile and having a fixing part for foundation concrete in the non-insertion part, and the pile head inner peripheral surface of the steel pipe pile facing the outer peripheral surface in the insertion part; A pile head jointing material characterized in that it is fixed to a steel pipe pile by a grout material filled in the gap of the pile.   The connecting member for pile head joining according to claim 1, wherein the fixing portion of the steel pipe body is a diameter-expanded portion protruding radially outward from the outer peripheral surface. The connecting member for pile head joining according to claim 1, wherein the fixing portion of the steel pipe body is a plurality of through holes penetrating the pipe wall. The pile head according to any one of claims 1 to 3, wherein a saddle-shaped portion that abuts against a pile head end face of the steel pipe pile is provided at a boundary between the insertion portion and the non-insertion portion of the steel pipe body. Connecting material for bonding. The sealing part which closes the crevice perimeter with the pile head inner peripheral surface which counters the outer peripheral surface in the lower end side in an insertion part was provided in the lower end part of the above-mentioned steel pipe. The connection material for pile head joining as described in any one of Claims.   A pile head joint structure in which the pile head of a steel pipe pile placed in the ground and the foundation concrete above it are joined via a connecting material that extends upward from the pile head and is embedded in the foundation concrete. In addition, the said connection material is the connection material for pile head joining as described in any one of Claim 1 thru | or 5. The pile head joining structure characterized by the above-mentioned.

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