JP2003253688A - Connection device between pile head and structural body and its installation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pile head connection device and an installation method for it capable of easily and economically realizing pile head connection for improving aseismatic safety performance of a pile. <P>SOLUTION: This pile head connection device is constructed of two members, that is, a recess type connection member and a projection type connection member, and the tip of the projection type member and the center of the recess type member inside face are brought into contact mutually. On the contact faces of the both members, a radius of curvature of a recess type member curved face is set to be larger than that of a projection type member curved face, and a clearance is secured between the both members around the contact faces, so that the projection type member can be freely tilted or deformed inside the recess type member curved face. In this way, a point contact condition can be offered in the pile head part in this pile head connection member. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

[Technical field to which the invention belongs] Experiences of earthquake disasters including the Great Hanshin-Awaji Earthquake in 1995 have pointed out the importance of seismic safety of not only the main body of the structure but also its foundation structure, especially the pile foundation. There is. The present invention relates to a method of joining pile heads that reasonably and economically enhances the seismic safety performance of a pile foundation that supports a structure.

[0002]

2. Description of the Related Art When constructing a structure on soft ground,
Various types of pile foundations such as steel piles, prestressed reinforced concrete piles, steel pipe-covered concrete piles, or cast-in-place concrete piles are used to support structures. The original purpose of these piles is to support the weight of the structure in normal times, but since many cases of pile damage have been reported in the past damaging earthquakes, it is important to improve the seismic performance of pile foundations in terms of seismic design. It has been pointed out as an issue.

The most general method of improving the seismic performance of piles is the stress during earthquake (= bending moment) generated in the pile body by being subjected to the forced deformation due to the horizontal force transmitted by the structure or the horizontal displacement of the stratum surrounding the pile. It is a method of increasing the horizontal strength (= bending strength and shear strength) of the pile body so that it can withstand the horizontal shear force). In Japan, various methods for increasing the horizontal bearing capacity of piles have been developed and put into practical use for many years.

In the previous methods for increasing the horizontal bearing capacity of piles, the pile body is rigidly connected to the upper structure or foundation footing by a rigid connection so as to restrain the rotational displacement of the pile head. Is a prerequisite. But,
On the contrary, in order to restrain the rotation of the pile head, a large bending moment and shear force are generated at the pile head during an earthquake.

As a method of eliminating this irrational, the conditions for joining the pile head are changed from "fixing the pile head" to "joining the pile head pin",
It has been conventionally known that, by changing to “semi-rigid joint” or “elastic rotary spring joint”, the stress during earthquake occurring in the pile head is theoretically significantly reduced.

[0006] In the wake of the Great Hanshin Awaji Earthquake, several attempts have been made in recent years to realize this pile head pin connection, and there are already practical methods. Pile head joint construction methods that have been put into practical use so far include those that introduce a ball seat into the pile head for rotary pin joints, those that use sliding bearings between the pile head and the bottom of the pile, Rotating spring joints with an elastic material such as rubber interposed between them, and the pile head is made smaller in cross section than the pile shaft to reduce bending rigidity, allowing plasticization and damage at that portion to prevent bending stress. There are things to try to limit.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a "pile head pin joint" or "pile head rotary spring joint" which can significantly reduce the stress generated in a pile body, particularly a pile head during an earthquake. The main objective is to provide "a method of joining the pile head and the structure or foundation footing above it" that can be realized economically.

Further, since it is a practical joining method,
The important conditions are "easy and quick construction", low cost and economical method, and "joining method with a wide range of application" that can be applied to both ready-made piles and cast-in-place concrete piles. .

In particular, the present invention makes it an important issue to realize a joining method that overcomes and solves the problems and weaknesses of each of the existing pile head pin joining methods that have been developed up to now as described in the above-mentioned prior art. Since the problems differ for each construction method, the problems and solutions of the following methods will be described below.

[0010]

The present invention adopts the following constitution in order to solve the above points. <Structure 1> A pile head joining device arranged between a head of a pile supporting a structure and a structure or a foundation footing of the structure, and an outer peripheral flat plate portion for transmitting a vertical load to the upper surface of the pile. And a pile-side joining member A having a concave portion that is a concave load receiving portion that is recessed in a mortar shape, and a concave portion of the pile-side joining member A that is arranged above the pile-side joining member A. It is composed of a base side joint member B consisting of a convex portion in contact with the central upper surface and a flat plate portion existing on the upper surface and joined to the upper base footing, and the pile side joint member A and the base side joint member B are On both contact surfaces, the radius of curvature of the recess of the pile-side joining member A is larger than the radius of curvature of the protrusion of the foundation-side joining member B, and the circumference of the protrusion of the foundation-side joining member B and the pile-side joining member. Make sure that a gap is secured between the inner wall surfaces of the A recess. Bonding apparatus of Kuitai head and the structure to symptoms.

<Structure 2> A pile head joining device arranged between a head of a pile supporting a structure and a structure or a foundation footing of the structure, and an outer circumference for transmitting a vertical load to the upper surface of the pile. A pile-side joining member A that has a flat plate portion and a convex portion that protrudes upward in the central portion, and a downward direction that is arranged above the pile-side joining member A and covers the convex portion of the pile-side joining member A. Of the pile-side joining member A and the pile-side joining member A, which has a concave portion serving as a concave load transmitting portion, and is formed of a flat plate portion existing on the upper surface and joined to the upper foundation footing. The foundation-side joining member B is in contact with each other in the center of the plane, and the radius of curvature of the recess of the foundation-side joining member B is larger than the radius of curvature of the protrusion of the pile-side joining member A at the contact surface, and the pile-side Between the convex portion of the joint member A and the base-side joint member B Bonding apparatus of Kuitai head and the structure, wherein a gap is secured between the inner wall surface of the part.

<Structure 3> In the pile head bonding apparatus according to Structure 1 or Structure 2, in the contact surface between the pile-side joining member A and the foundation-side joining member B, the vicinity of the central contact portion between the convex portion and the concave portion is almost the same. It has a flat plate shape (radius of curvature ≈ infinity), and the convex portion can be displaced horizontally with respect to the concave portion within the range, and the pile-side joining member A and the foundation-side joining member B are A device for joining a pile head and a structure, which is capable of relatively oblique deformation and horizontal deformation.

<Structure 4> In the pile head bonding apparatus according to any one of Structures 1 to 3, the contact surfaces of the pile-side joining member A and the foundation-side joining member B are the central contact portions of the convex portion and the concave portion. There is a tip fitting part consisting of small irregularities near the center to limit the deviation of the two-dimensional positional relationship, and between the convex part of the tip fitting part and the inner wall surface of the recess of the tip fitting part. In the above, the pile-side joining member A and the foundation-side joining member B have a slight gap to allow relative inclination deformation, and a joining device for a pile head and a structure.

<Structure 5> In the pile head bonding apparatus according to any one of Structures 1 to 3, the displacement at the central contact portion between the pile-side joining member A and the foundation-side joining member B is a certain value or more. Or the relative inclination angle between both the pile-side joining member A and the foundation-side joining member B reaches a certain value or more, the protrusions of both the pile-side joining member A and the foundation-side joining member B are convex. Make sure that the peripheral wall and the inner wall surface of the recess are in contact,
A joining device for a pile head and a structure, wherein a gap is set between the pile-side joining member A and the foundation-side joining member B.

<Structure 6> In the pile head bonding apparatus according to any one of Structures 1 to 3, the pile-side bonding member A and the pile-side bonding member A are included in the gap between the pile-side bonding member A and the foundation-side bonding member B. The peripheral gap in the vicinity of the central contact portion between the base-side joining members B is small, and when the central contact portion is displaced by a certain amount or more, only the vicinity of the tip of the convex portion comes into contact with the side wall of the concave portion. A device for joining a pile head and a structure, which is set.

<Structure 7> In the pile head bonding apparatus according to any one of Structures 1 to 3, near the contact surfaces of the central contact portions of both the pile-side joining member A and the foundation-side joining member B, or the recessed portion. On the peripheral wall surface facing the convex portion and the convex portion, a coating layer of a lubricating liquid, a coating layer of a rust preventing liquid, a filling portion of the lubricating liquid,
A device for joining a pile head and a structure, wherein a filling portion for a rust preventing liquid, a solid lubricant film, or an elastic material is interposed.

<Structure 8> In the pile head joining device according to any one of the above structures 1 to 3, the backfill soil around the pile head is mixed in the gap between the pile side joining member A and the foundation side joining member B. A device for connecting a pile head and a structure, which is filled with a foam material or a sponge-like substance so as not to do so.

<Structure 9> In the pile head bonding apparatus according to any one of Structures 1 to 3, a gap between the pile-side joining member A and the foundation-side joining member B, or a peripheral flat plate portion of the pile-side joining member and the same. An elastic material is disposed between the upper foundation-side joint members to give a restoring force to the relative displacement and inclination of the pile-side joint member A and the foundation-side joint member B to prevent horizontal deformation and rotational deformation of the pile head. A device for joining a pile head and a structure, which uses elastic spring joining and at the same time prevents entry of backfilling soil around the device.

<Structure 10> In the pile head bonding apparatus according to any one of Structures 1 to 3, the stud bolts are joined by welding to the upper surface of the flat plate for joining above the base-side joining member B, and joined by screwing. It has a stud bolt or a protrusion fixed to the footing side of the upper foundation, and the concrete of the structure foundation is placed on the upper portion of this protrusion to connect the flat plate for joining and the upper structure. -A device for joining a pile head and a structure, which can be integrated.

<Structure 11> In the pile head bonding apparatus according to Structure 1, the outer circumference of the recess of the pile-side bonding member A is slightly smaller than the inner diameter of the ready-made pile head, and the space between the pile-side bonding member A and the pile body is small. A device for joining a pile head and a structure, which is capable of transmitting a horizontal shearing force by contacting the inner wall surface of the inner diameter of the pile when a slight horizontal shift occurs in the pile.

<Structure 12> In the pile head joining apparatus according to the above-mentioned Structure 2, a cylindrical insert portion slightly smaller than the inner diameter of the ready-made pile head is provided below the pile side joining member A, and the pile side joining member is provided. When a slight horizontal displacement occurs between A and the pile body, it can contact the inner wall surface of the inner diameter of the pile body to transmit a horizontal shearing force, and a joining device for a pile body head and a structure.

<Structure 13> In the pile head bonding apparatus according to any one of Structures 1 to 12, the pile-side joining member A and the foundation-side joining member B are made of steel or castings. Joining device for pile head and structure.

<Structure 14> Using the pile head bonding apparatus according to any one of Structures 1 to 13, the outer diameter of the recess of the bonding member A is made slightly smaller than the inner diameter of the steel pipe ready-made pile,
When the steel pipe pile is inserted into the inner surface of the upper end after piling or the upper end cut after piling, and the level of the pile-side joint member A can be set below a certain value, leave it as it is, and the level of the pile-side joint member A is constant. A method for installing a pile head joining device to a steel pipe pile, characterized in that when the pile side joining member A is held horizontally, the pile body and the pile side joining member A are welded and joined when the pile head joining member A is kept horizontal.

<Structure 15> The pile head joining device according to any one of Structures 1 to 13 is inserted into the inner surface of the upper end of a ready-made concrete pile or a steel pipe-covered ready-made concrete pile,
If the level of the pile-side joint member A can be set below a certain value, leave it as it is. If the level of the pile-side joint member A cannot be maintained below a certain value, after repairing the pile top surface horizontally with a curable material , A method for installing a pile head joining device on a concrete prefabricated pile, characterized in that the pile side joining member A is inserted into the inner surface of the upper end of the pile.

<Structure 16> The pile head bonding apparatus as a whole according to any one of Structures 1 to 13 or a pile side bonding member A
Only, or a cylindrical member slightly larger than the outer diameter of the concave portion of the pile-side joining member A is installed at a predetermined position before concrete casting of cast-in-place concrete piles, and the pile concrete is cast, and the remaining B after hardening is applied. A method for installing a pile head joining device on a cast-in-place concrete pile, which is characterized by inserting and installing a part or the whole.

<Structure 17> The whole pile head bonding apparatus according to any one of Structures 1 to 13 or only the pile side bonding member A is installed at a predetermined position after concrete casting of cast-in-place concrete piles, A post-strike anchor bolt is driven on site to fix the pile head joint device at the anchor bolt hole position provided on the peripheral flat plate portion of the pile side joint member A, and a sponge-like substance such as expanded polystyrene or expanded urethane is provided around it. A method for installing a pile head joining device to a cast-in-place concrete pile, which is characterized in that it is placed and concrete is laid on the foundation side. <Outline> First, the pile head pin joining method (Fig. 1), which introduces a ball seat into the pile head of the above existing method, makes it relatively easy to support a large load because the ball seat is usually made of steel. Although it has the advantage of being easy, it has a fatal flaw in its basic mechanism. That is, in the spherical seat, both concave and convex spherical surfaces having the same radius of curvature are in face-to-face contact with each other, and the radius of curvature is usually around 10 cm, and even if large, it does not exceed several tens of cm. On the other hand, the deformation of the pile during the earthquake causes an inclination due to the horizontal shear displacement of the stratum, so the rotation center position near the pile head is 2 to 3 m below the pile head (radius of curvature ≈ 2
It is often up to 3 m) or several m below (curvature radius ≈ several m) or more, and its position varies depending on the combination of pile and ground conditions and earthquake motion.

Since the foundation footing on the upper side of the pile is constrained from rotating by the underground beam, the upper surface side of the ball seat does not rotate, and only the pile is inclined and deformed. Therefore, in pin joining using a ball seat, as shown in FIG. 2, the center of rotation of the ball seat does not match the center of rotation of the pile inclination, so normal rotation motion of the ball seat cannot be established, and the contact surface does not touch the mouth. There is a gap that opens. As a result, a very large frictional force may be generated, foreign matter may be mixed into the spherical surface having a gap to impair the function of the ball seat, or the ball seat itself may be damaged in some cases.

To solve this drawback, the basic mechanism of the spherical seat, that is, the surface contact with the same curvature, is abandoned. That is, the present invention negates the conventional surface contact condition of the ball seat and establishes the point contact condition. Although there is no point contact without an area in reality, the point is to establish the point contact condition at the pile head joint position when macroscopically observing the inclined deformation state of the pile. For this purpose, two concave and convex members are provided on both the pile-side joining member and the foundation-side joining member, and the radius of curvature on the concave side is set to be larger than the radius of curvature on the convex side on the contact surface. Then, a gap is secured around the convex member that is slightly apart from the contact portion between the both. By these two conditions, the convex pile material having a small radius of curvature can be freely tilted with respect to the concave material, and as a result, the point contact condition is satisfied. Since the radii of curvature of the unevenness are originally different from each other, it is possible to smoothly incline and rotate the pile material regardless of the position of the center of rotation of the pile material.

Next, the existing method of sliding support between the pile head and the bottom of the foundation also has a fatal defect. That is,
As shown in Fig. 3, since the pile material itself is inclined, the slip surface itself of the pile head is also inclined, and the sliding surface side of the foundation bottom is rotationally constrained by the underground beam. A gap is generated on the surface due to the inclination, and the normal sliding surface mechanism is not established. There is also an assertion that this mechanism can be expected to have a seismic isolation effect, but the foundation floor itself is buried in the ground, and the seismic isolation effect is achieved while the ground and structure (foundation body) are integrated. The claim to expect has a fundamental contradiction.

However, there is another meaning in introducing "a certain amount of relative slip" between the pile head and the foundation bottom. That is, the relative displacement is effective from the viewpoint that the inertial force at the time of the earthquake generated on the building side is not transmitted to the piles and the seismic force in the building is made to flow to the ground side as much as possible. This is a new perspective that was not found in the conventional design concept of pile foundations.
In the present invention, slip that takes only that advantage = "shift"
Is incorporated. However, if this gap becomes too large,
Since the Pδ moment due to the deviation is added to the pile, the deviation amount is limited to a small value, which is an important condition. Further, according to the present invention, the contact surfaces of the two are configured by curved surfaces having different radii of curvature so that the slip condition is not broken even by the relative inclination of the contact surfaces, and the slippable region is limited to a small range. is doing. This is configuration 3.

Up to now, two types have been put into practical use in which a spring spring is to be joined by interposing an elastic material such as rubber on the pile head of the existing construction method. One is to enclose a ring-shaped rubber body in the groove, which has a drawback that the meshing mechanism is easily disengaged due to rotation and pulling force. The other uses a laminated rubber body in which one layer or a thin rubber layer of about 2 to 3 layers is vulcanized and adhered to a steel plate. It has no mechanical defects and is ideal for elastic performance. It realizes joining. The weak point of this method is that the use of a rubber material limits the working surface pressure of the working load, and the area of the device increases, resulting in some manufacturing cost.

However, the use of a rubber elastic body has an advantage that an elastic restoring force spring cannot be obtained by other methods. Therefore, in the present invention, the vertical load secures a large load supporting ability by supporting the steel materials of both the concave and convex members, and a rubber body is interposed in the gap between the concave and convex joints to obtain an elastic restoring force, The solution is to obtain elastic restoring force. As a result, the present invention makes it possible to economically realize "elastic rotary spring joining" even with a large vertical load.

Regarding the existing construction method in which the pile head is made smaller in cross section than the pile shaft portion to reduce the bending rigidity, and the plasticization and damage of the portion are allowed to limit the generation of bending stress,
The idea of “allowing the plasticization and damage of the pile head” allows cost reduction, but does not conform to the design idea of the present inventor whose primary purpose is to improve seismic safety. The idea of the pile head joining method is to improve the seismic performance of the pile and prevent damage to the pile body, but the method that assumes damage to the most important part is a solution that forgets the purpose. However, this method is an extremely incomplete solution because it contradicts the original purpose and cannot be repaired once it has been damaged. Therefore, the present invention denies and does not employ such a solution.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing embodiments.

FIG. 1 is a basic configuration diagram of a conventional pile head pin connection using a ball seat, and FIG. 2 is an explanatory diagram that the basic mechanism collapses during an earthquake. As shown in Fig. 2 (2), the rotation of the upper foundation footing is restricted by the underground beam, and the pile side inclines when an earthquake occurs, so the rotation center of the ball seat and the rotation center of the pile head do not match, This spherical seat system has a fatal defect in the basic principle.

FIG. 3 shows that the basic mechanism is not normally established even in the case of pile head slip joints (which may be erroneously called pile head roller joints) using conventional slide bearings. FIG. Fig. 3 (1) shows the case where the slip plate is on the pile side, and (2) shows the case where the slip plate is on the foundation footing side. In both cases, the slip surface is the mouth because the pile side only inclines and rotates during an earthquake. Open, and the contact condition of the normal sliding surface is not satisfied. In addition, since the eccentric moment Pδ (P is an acting vertical load) acts on the pile due to this slip amount δ, a large moment far exceeding the moment that can be released by pin joining acts on the pile head when the slip amount becomes excessive. I will let you.

FIG. 4 shows the basic constitution of the present joining apparatus defined in constitution 1. When FIG. 4 (1) is applied to a steel pipe pile, FIG. 4 (2) shows a concrete-based ready-made concrete pipe containing a steel pipe coating. When applied to piles, FIG. 4 (3) exemplifies the case applied to cast-in-place concrete piles.

FIG. 5 shows a configuration 2 in which the concavo-convex configuration is turned upside down.
5 (1) is applied to a steel pipe pile, FIG. 5 (2) is applied to a concrete prefabricated pile including a steel pipe coating, and FIG. 5 (3) is a cast-in-place concrete. This is an example of application to a pile.

FIG. 6 illustrates the basic principle of the present joining device. FIG. 6 (1) shows the case of configuration 1 and FIG.
Is the case of configuration 2 and FIG. The former (Structure 1 / Figure 4)
Is configured to bear the load on the pile-side joining member A in a tensile stress state, and the latter (Configuration 2 and FIG. 5) is configured to bear the load on the pile-side joining member A in a compressive stress state. There is.

Both AB members have a member cross section that is sufficiently safe to bear the supporting load, but since this member is usually made of steel or a casting such as ductile cast iron, the tip cross-sectional area of the convex member corresponds to the pile shaft cross section. On the other hand, it is possible to make it small enough to be regarded as a point contact. Further, the convex member tip has a smooth curved surface, and the concave portion contacting the convex member is configured as a saucer of a curved surface having a larger radius of curvature, and a gap is secured around it, so that both the concave and convex members can be freely inclined and deformed. Is possible. FIG. 6C shows a method of forming a curved surface on the contact surfaces of both the concave and convex members.

When the pile material is tilted during an earthquake, the convex member of this device tilts (= rolls) around the tip contact portion, so that the sliding movement of the contact surface is performed like the conventional ball bearing. Not a thing. Sliding friction of a spherical surface causes a large amount of sliding friction, which results in a large resistance force.However, in this device, the mechanism of the basic motion is not rolling but rolling rolling motion of the contact surface. Does not occur.

FIG. 7A shows a case where a small concave-convex fitting portion is provided at the center of the contact surface in order to prevent the position of the tip of the convex portion from shifting. However, it is important to provide a sufficient allowance in the fitting portion of the both so that the fitting portion does not hinder the inclination deformation of the both. This is the content of configuration 4.

Further, since this contact portion is basically a rolling motion as described above, the horizontal resistance is extremely small. For this reason, it is preferable to secure a certain amount of shear strength in the convex member cross section of the convex-concave portion at the tip, and in order to transmit a large horizontal shearing force to the pile, the gap between the convex member and the concave member should be set appropriately. The shape is set so that both of them will come into contact with each other at a certain inclination deformation or more and the device can exhibit sufficient shear strength. This is the content of configuration 5.

In order to prevent the horizontal displacement from occurring in the vicinity of the contact portion between the concave and convex members and at the same time reliably transmit the horizontal shearing force, it is necessary to make the gap near the tip of the convex member small. Is. For this reason, FIG. 7B and FIG. 7 show that the shift-preventing projection is formed on the concave side.

The method for constructing the pin joining mechanism by point contact between both AB members has been described above.

As described in the explanation of the existing construction method, as the pile head joint construction method, by combining this pin joint construction method with "a slight amount of slip area", it is possible to construct the pile side without adding an excessive Pδ moment to the pile side. More seismic inertial force can be directly transmitted to the ground side. In order to form the slip region, the radius of curvature of the contact portion on the concave member side is increased to approach the flat plate, and then a stopper projection portion for limiting excessive slip is formed. FIG. 7C shows an example of the configuration, which is a configuration in which the configurations 3 and 6 are combined.

In FIG. 7 (3), smoother sliding can be generated and frictional force can be reduced when the frictional resistance between the contact portions of both AB members is smaller. Configuration 7 shows a method of improving the lubrication performance of this contact portion, which is the most important portion in the present joining device, and also taking measures to prevent rust on the contact surface and the surfaces of both the concave and convex members (the inner surface of the concave member). It is a thing. As a method that can satisfy both functions of lubrication and rust prevention at the same time, a method of filling the inside of the recessed material with a lubrication and rust prevention liquid such as grease, oil, rust prevention oil, and viscous fluid, solid lubrication such as PTFE and molybdenum disulfide There is a method of forming an agent film, and an elastic film such as a rubber film can be interposed between a gap and a contact surface between the two.

The present joining device is usually placed on the pile head and backfilled in the soil. At this time, if backfilling soil, gravel or sand from the ground breaking work, or waste concrete is mixed into the gap between the joining members AB, the deformability of the joining device may be impaired. In order to prevent this loss of function and ensure the reliable operation of this apparatus, a sponge-like substance such as urethane foam or styrene foam is filled in the gap between both joining members AB as shown in FIGS. This is composition 8
Is. Although these members are sufficient to prevent backfilling soil and the like, they are extremely soft materials and do not affect the operation of this device during an earthquake.

Since the present joining device is a point contact mechanism for both concave and convex members, rotational deformation is extremely easy and almost no resistance force is generated. As a method of applying an elastic restoring force to the main joining device, a rubber body is interposed in a gap between both AB on the peripheral portion of the main joining device as shown in FIG. 9, and the restoring force is applied by elastic deformation thereof. it can. Further, as shown in the lower part of FIG. 9 (2), an elastic material may be filled in the entire gap between the AB members to provide both restoring force and rust preventive performance. In this device, the vertical load is transmitted by direct contact between the concave and convex members, and it is not necessary for the rubber body to bear the vertical load. Therefore, the restoring spring performance can be easily adjusted. Also, this rubber body is A
B It also fulfills the function of preventing backfilling soil from entering the gap between them.

Structure 10 and FIG. 8 relate to a method of joining the present joining device and the upper foundation concrete. In this joining device, stud bolts are attached to the upper surface of the flat plate by welding or screwing. Further, as shown in FIG. 8, it is also effective to drive the fixing protrusion into the basic footing, which also has the function of fixing the protrusion. Since the upper foundation and this device can be integrated by simply placing the foundation concrete on the upper portion of the joining member B in which the stud bolt and the protrusion for fixing are prepared in advance, the installation work is simple and quick construction is possible.

Structures 11 and 12 relate to a method of joining the pile body and the main joining device in the case of a ready-made pile. As shown in FIGS. 4, 5 and 8, the lower part of the device is the inner diameter of the pile head. It is made slightly smaller, and the installation of this device is completed simply by inserting this device into the inner cylindrical portion of the pile head. The insertion depth of this device is usually about 10 cm or more,
Even if there is a vertical movement, this device does not come out of the pile. Originally, this device does not resist lifting and does not transmit tensile force to the pile.

Structure 13 is a main joining member A of the present joining device.
The constituent material of B is specified, and it is manufactured by a steel material or a casting (cast iron). In particular, the concavo-convex shape of this device is suitable for casting molding, and ductile cast iron is a typical material.

Structures 14 to 17 define the installation method and construction method of the present joining device. Structure 14 / Fig. 10
Shows the installation method of the present joining device for steel pipe piles. The pile head after driving the steel pipe pile can be driven to a predetermined height, and the inclination angle of the pile is not large (usually, the inclination angle ≤ 1/100 rad)
In this case, it suffices to insert the joining device into the inside of the pile head of the steel pipe pile. When the inclination of the steel pipe pile is large and the pile head of the steel pipe pile is gas-cut after the pile is laid, as shown in Fig. 10, this device is inserted inside the pile head and the device is kept horizontal. Weld the pile and this device together. By this method, even if the steel pipe pile is tilted or the pile head cut surface is jagged due to gas cutting, this joining device is installed horizontally and the vertical load is normally transmitted to the pile, and in the event of an earthquake The pile can be protected as a pile head pin joint.

Structure 15: FIG. 11 shows a method of installing the present joining apparatus on a concrete prefabricated pile including a steel pipe coating. If the piles that have been placed are placed vertically,
All that is required is to insert the joining device inside the pile head. If the pile has a large inclination (usually> 1/100 rad), repair the top of the pile horizontally with epoxy resin or high-strength mortar, and install this device after the strength is manifested.

Structures 16 and 17 show a method of installing the present joining device on cast-in-place concrete piles. Configuration 16
-Fig. 12 shows a construction method when the central portion of the joining member A is projected downward, and as shown in Fig. 12 (1), the entire joining device or the joining member A is placed before concrete placing of the cast-in-place concrete pile. 12 in place or
As shown in (2), it is a method of placing the concrete of the pile after attaching the cylindrical member into which the central portion of the joining member A can be inserted. If this method of mounting the device before concrete placement is not used, it is necessary to make a hole in the concrete of the pile head in order to mount the device in which the bottom of the joining member A is convex downward. , It takes a lot of time and effort.

Structure 17: FIG. 13 shows a construction method when a device having a flat bottom of the joining member A is installed.
After the concrete of the cast-in-place concrete pile is hardened, the installation position of this device is leveled flat, the device is installed horizontally on a thin mortar, etc., and then the anchor bolt is post-dried (Fig. 13 (2)). . In the case of cast-in-place concrete piles, this method can easily install the joining device at a predetermined position, and then, as shown in Fig. 13 (3), a soft buffer such as styrene foam or urethane foam around the device. Lay the material and place the foundation concrete on top.

[0057]

As described above, when the pile head joining device of the present invention is adopted, the following effects can be obtained in joining a pile body to a structure or foundation footing, and in addition to the existing pile head pin joining method. However, advantageous conditions can be realized. The pin head and foundation footing can be joined with almost perfect pin joints. Further, the pile head can be an elastic rotary spring joint having an appropriate restoring force. In addition, a slight slip deformation can be allowed between the foundation bottom and the pile head, and the horizontal force transmitted to the pile can be reduced. As a result, the stress generated at the head of the pile body during an earthquake can be significantly reduced, and the seismic safety performance of the pile body can be dramatically improved. Since the stress generated at the head of the pile during an earthquake is dramatically reduced,
The cross section of the underground beam can be made smaller, resulting in a shallower foundation floor, reduced excavated soil volume, and a significant reduction in overall construction costs. The present joining device can handle a small vertical load of 10 tons / piece to a large load of 1000 tons / piece or more. This joining device is used for small diameter steel pipe piles, ready-made concrete piles,
It can be applied to all types of steel pipe covered concrete piles (SC piles) and cast-in-place concrete piles. It has good workability for all types of piles and can be built in a very short period of time. In particular,
After the construction of the pile body, the construction is completed simply by installing this device on the pile head and placing the foundation footing or the concrete of the structure on the top of the pile body, so the construction can be performed easily, easily and quickly. The joining members A and B of the present joining device are suitable for casting molding, can be manufactured at low cost, and have good workability. Therefore, both the device and the installation work are economical with the pile head joining method. is there.

As described above, according to the present invention, it is possible to quickly construct a pile head pin joint capable of greatly reducing the stress of the pile body during an earthquake, a pin joint joint with some slip, and an elastic rotary spring joint by a simple construction method. Is made possible. Moreover, since it can handle all types of piles from small loads to large loads, and can be supplied at low cost, the practicality of the present invention is extremely high, and a pile foundation structure excellent in seismic safety performance can be economically provided. It was possible to realize.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a conventional pile head pin joining device using a ball seat.

[Fig. 2] Defect explanation diagram of the conventional pile head pin joining device using a ball seat (1) Deformation state of a pile under a building during an earthquake (2) Center of curvature of a ball seat near the pile head and center of rotation of the pile Illustration of the principle that the two do not match

[Fig. 3] Defect explanation diagram of conventional pile head slide (roller) joining using a slide bearing (1) Deformation state during an earthquake when the slide plate is installed on the pile side (lower side) (2) Basic footing of the slide plate Deformation during earthquake when installed on the side (upper side)

FIG. 4 is a sectional configuration explanatory view of the pile head joining device of the present invention (when the concave load receiving portion is arranged on the lower side (pile side))
(1) Example of device cross-sectional configuration when applied to steel pipe piles (2) Example when applied to concrete concrete prefabricated piles (including SC piles) (3) Example when applied to cast-in-place concrete piles

FIG. 5 is a cross-sectional configuration explanatory view of the pile head joining device of the present invention (when the concave load receiving portion is arranged on the upper side (foundation footing side)) (1) Cross-sectional configuration example of the device when applied to a steel pipe pile (2) Example of application to ready-made concrete piles (including SC piles) (3) Example of application to cast-in-place concrete piles

FIG. 6 is a mechanism explanatory view of the operation principle of the device of the present invention (1) When the concave load receiving portion is arranged on the lower side (pile side) (2) When the concave load receiving portion is arranged on the upper side (foundation footing side) (3) Explanatory view of curvature of the uneven member contact portion

FIG. 7 is an explanatory view of a configuration around the contact portions of both the concave and convex members (1) When a tip fitting portion is provided at the center of the contact portion (2) When a protrusion for preventing deviation is provided on the concave material side near the tip of the convex member (3) In the case where a sliding area is formed in the contact portion and the deviation preventing protrusion of (2) above is provided in the recessed material outside thereof.

FIG. 8 is a structural explanatory view of a member for joining a pile and a foundation. (1) For steel pipe piles (2) In case of ready-made concrete piles (including SC piles) (3) For cast-in-place concrete piles

[Fig. 9] An example of a construction method in which a restoring force of a rotary elastic spring is imparted by an elastic material such as rubber (1) In the case of a steel pipe pile (2) In the case of a concrete-based ready-made pile (including SC pile) (3) Cast-in-place concrete For piles

[Fig. 10] An explanatory view of a construction method when the present joining device is installed in a steel pipe pile (1) Cutting of a steel pipe pile head and suspending the device (2) On-site welding while the device is kept in a predetermined position, Removal of hanging bolts (3) Installation state of the device with a convex top

FIG. 11 is an explanatory view of a construction method when the main joining device is installed in a concrete-based ready-made pile (including SC pile) (1) Suspending the main joining device (2) After installing the device, removing the hanging bolts and upper foundation concrete Casting

[Fig. 12] An explanatory view of a construction method when the present joining device is installed in a cast-in-place concrete pile (in the case of a device in which the recessed material is exposed on the lower side) (1) The lower recessed material or the entire device is placed at a predetermined position. After arranging and fixing with a rebar cage or temporary member, a method of placing pile concrete (2) A cylindrical member into which the lower concave material can be inserted and installed later is attached before pile concrete placing, and pile concrete is placed. Installation method to install this device later (3) Same as above Inserting and installing this device into a cylindrical member and fixing with a grout

[Fig. 13] An explanatory view of a construction method when the present joining device is installed on a cast-in-place concrete pile (in the case of a device having a recessed material on the upper side) (1) Construct cast-in-place concrete as usual The device installation position is leveled, and the device member A (lower side) is suspended. (2) The device member A is installed and the anchor bolt is post-struck on site. (3) The device member B (upper side) is hung up and installed, and a protective material such as Styrofoam that prevents the interference of upper and lower concrete and the mixture of backfilling soil is arranged around it, and then the basic concrete on the upper part of the device is placed. To set.

[Explanation of symbols]

1: Building or superstructure 10: Foundation footing 11: Underground beam 2: Pile 21: Steel pipe pile 22: Concrete-made prefabricated pile (including SC pile) 23: Cast-in-place concrete pile 24: Reinforcing cage for pile 3: Ball seat Pile head pin joining device 3A: Pile side member 3B: Foundation footing side member 31: Contact sliding surface of ball seat 4: Pile head joining device 41 by sliding bearing 41: Sliding plate 42: Sliding surface supporting member 5: of the present invention Pile head joining device (when the concave member is on the pile side (lower side)) 5A: Pile side joining member (concave member) 5B: Foundation side joining member (convex member) 5C: Gap filling cushioning material 5D: Elasticity for restoring force Body (rubber body) 51: Recessed material side contact surface 52: Slip clearance 53: Stopper protrusion 54: Foundation side fixing flat plate 55: Stud bolt 56: Fixing protrusion 57: Installation hanging bolt 58: Cylindrical type Driving frame 59: Grout material 6: Pile head joining device of the present invention (the concave member is the foundation frame) 6A: pile side joining member (convex member) 6B: foundation side joining member (concave member) 6C: gap filling cushioning material 6D: elastic body for restoring force (rubber body) 61: concave Member side contact surface 64: Foundation side fixing flat plate 65: Stud bolt 66: Anchor bolt

Claims (17)

[Claims] 1. A pile head joining device arranged between a head of a pile supporting a structure and a structure or a foundation footing of the structure, wherein an outer peripheral flat plate portion for transmitting a vertical load to the upper surface of the pile. And a pile-side joining member A having a concave portion that has a concave load receiving portion that is recessed in a mortar shape, and a concave portion of the pile-side joining member A that is arranged above the pile-side joining member A. The base side joint member B is composed of a convex portion that contacts the central upper surface of the base and a flat plate portion that is present on the upper surface and that is joined to the upper foundation footing. In both contact surfaces, the radius of curvature of the concave portion of the pile-side joint member A is larger than the radius of curvature of the convex portion of the base-side joint member B,
Moreover, a gap is secured between the periphery of the convex portion of the base-side joining member B and the inner wall surface of the recess of the pile-side joining member A, and the joining device for a pile head and a structure. 2. A pile head joining device arranged between a head of a pile supporting a structure and a structure or a foundation footing of the structure, and an outer peripheral flat plate portion for transmitting a vertical load to the upper surface of the pile. And a pile-side joining member A having a convex portion with a central portion protruding upward.
And a recessed portion that is arranged on the upper side of the pile-side joint member A and serves as a downward concave load transmission portion that covers the convex portion of the pile-side joint member A, and that exists on the upper surface of the upper footing. It is composed of a foundation side joining member B composed of flat plate portions to be joined, and the pile side joining member A and the foundation side joining member B are in contact with each other in the plane center of both, and the foundation side joining member B is in the contact surface. The radius of curvature of the concave portion is larger than the radius of curvature of the convex portion of the pile-side joining member A, and a gap is secured between the periphery of the convex portion of the pile-side joining member A and the inner wall surface of the concave portion of the foundation-side joining member B. A device for joining a pile head and a structure, which is characterized by being provided. 3. The pile head joining apparatus according to claim 1 or 2, wherein the contact surface between the pile-side joining member A and the foundation-side joining member B is substantially in the vicinity of the central contact portion between the convex portion and the concave portion. It has a flat plate shape (radius of curvature ≈ infinity), and the convex portion can be displaced horizontally with respect to the concave portion within the range, and the pile-side joining member A and the foundation-side joining member B are A device for joining a pile head and a structure, which is capable of relatively oblique deformation and horizontal deformation. 4. The pile head joining apparatus according to any one of claims 1 to 3, wherein a contact surface between the pile-side joining member A and the foundation-side joining member B has a center of a central contact portion between a convex portion and a concave portion. In the vicinity, there is a tip fitting part consisting of small irregularities for limiting the deviation of the plane positional relationship between the two, and between the periphery of the convex part of the tip fitting part and the inner wall surface of the concave part of the tip fitting part. Is the pile-side joining member A and the foundation-side joining member B
Has a slight gap that allows relative inclination deformation, and a joining device for a pile head and a structure. 5. The pile head joining apparatus according to any one of claims 1 to 3, wherein a deviation at the central contact portion between the pile side joining member A and the foundation side joining member B is a certain value or more. When it reaches or when the relative inclination angle between both the pile-side joining member A and the foundation-side joining member B reaches a certain value or more, the protrusions of both the pile-side joining member A and the foundation-side joining member B A joining device for a pile head and a structure, wherein a gap between the pile-side joining member A and the foundation-side joining member B is set so that the peripheral wall and the inner wall surface of the recess come into contact with each other. 6. The pile head joining apparatus according to any one of claims 1 to 3, wherein the pile side joining member A and the foundation are included in a gap between the pile side joining member A and the foundation side joining member B. The peripheral gap in the vicinity of the central contact portion between both side joining members B is small, and when the central contact portion is displaced by a certain amount or more, only the vicinity of the tip of the convex portion is set to contact the side wall of the concave portion. A device for joining a pile head and a structure, which is characterized by being provided. 7. The pile head joining apparatus according to claim 1, wherein the pile side joining member A and the foundation side joining member B are both in the vicinity of a contact surface of a central contact portion, or in the concave portion. A coating layer of a lubricating liquid, a coating layer of a rust preventing liquid, a filling portion of a lubricating liquid, a filling portion of a rust preventing liquid, a solid lubricant film, or an elastic material is provided on the peripheral wall surfaces facing each other of the convex portion. A device for joining a pile head and a structure, characterized by being interposed. 8. The pile head joining apparatus according to any one of claims 1 to 3, wherein the gap between the pile side joining member A and the foundation side joining member B does not contain backfill soil around the pile head. As described above, a device for connecting a pile head and a structure, which is filled with a foam material or a sponge-like substance. 9. The pile head joining apparatus according to claim 1, wherein a gap between the pile-side joining member A and the foundation-side joining member B, or a peripheral flat plate portion of the pile-side joining member and an upper portion thereof. An elastic material is disposed between the foundation-side joining members of No. 1, and a restoring force against the relative displacement and inclination of the pile-side joining members A and the foundation-side joining members B is applied to provide elasticity to the horizontal and rotational deformation of the pile head. A joining device for a pile head and a structure, which is spring-joined and at the same time prevents backfilling soil around the device from entering. 10. The pile head joining apparatus according to any one of claims 1 to 3, wherein a stud bolt joined by welding and a stud joined by screwing are provided on an upper surface of the joining flat plate above the foundation-side joining member B. It has a bolt or a protrusion that is fixed to the upper foundation footing side.By placing a concrete of the structure foundation on the upper portion of this protrusion, the above-mentioned joining flat plate and the upper structure are connected. A device for joining a pile head and a structure, which can be integrated. 11. The pile head joining device according to claim 1, wherein the outer circumference of the recess of the pile side joining member A is slightly smaller than the inner diameter of the ready-made pile head, and the gap between the pile side joining member A and the pile body. A joining device between a pile head and a structure, which is capable of transmitting a horizontal shearing force by contacting an inner wall surface of the inner diameter of a pile when a slight horizontal shift occurs. 12. The pile head joining device according to claim 2, wherein a cylindrical insert portion slightly smaller than the inner diameter of the ready-made pile head is provided in the lower portion of the pile side joining member A. When a slight horizontal displacement occurs between the pile body and the pile body, it is possible to contact the inner wall surface of the inner diameter of the pile body and transmit the horizontal shearing force. 13. The pile head joining device according to claim 1, wherein the pile-side joining member A and the foundation-side joining member B are made of steel or casting. A device that joins the body to the structure. 14. The pile head joining apparatus according to claim 1, wherein the outer diameter of the recess of the joining member A is made slightly smaller than the inner diameter of the steel pipe prefabricated pile. If it can be installed on the inner surface of the upper end after installation or the upper end cut after driving, and if the level of the pile-side joining member A can be installed below a certain value, leave it as it is, and keep the level of the pile-side connecting member A below a certain value. When it is not possible to secure the pile side joining member A, the pile head and the pile side joining member A are welded and joined in a state where the pile side joining member A is kept horizontal. 15. The pile head joining device according to any one of claims 1 to 13 is inserted into an inner surface of an upper end of a ready-made concrete pile or a steel pipe-covered ready-made concrete pile, and the level of the pile-side joining member A is constant. If it can be installed below the value, leave it as it is, and if the level of the pile-side joint member A cannot be maintained below a certain value, after repairing the pile top surface horizontally with a curable material, the pile-side joint member A is A method for installing a pile head joining device, which is characterized in that it is inserted into an inner surface, on a concrete prefabricated pile. 16. The whole pile head joining device according to any one of claims 1 to 13 or only a pile side joining member A,
Alternatively, a cylindrical member slightly larger than the outer diameter of the concave portion of the pile-side joining member A is installed at a predetermined position before concrete-casting of cast-in-place concrete piles, the pile concrete is cast, and the remaining part B after hardening or A method for installing a pile head joining device to a cast-in-place concrete pile, which is characterized in that the whole is inserted and installed. 17. The pile head joint apparatus according to any one of claims 1 to 13 or only the pile side joint member A is installed at a predetermined position after concrete casting of cast-in-place concrete pile, A post-strike anchor bolt is struck on site to fix the pile head joining device at the position of the anchor bolt hole provided on the peripheral flat plate portion of the side joining member A, and a sponge-like substance such as styrene foam or urethane foam is placed around it. A method for installing a pile head joining device to a cast-in-place concrete pile, characterized by placing concrete on the foundation on the upper part of the slope.