JP3741426B2 - Pile head and structure joining apparatus and installation method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The experience of earthquake disasters including the 1995 Hanshin-Awaji Earthquake has pointed out the importance of seismic safety not only for the structure itself but also for the foundation structure, especially the pile foundation. The present invention relates to a method for joining pile heads that rationally and economically improves the seismic safety performance of a pile foundation that supports a structure.
[0002]
[Prior art]
When constructing structures on soft ground, various pile foundations such as steel piles, prestressed reinforced concrete piles, steel pipe covered concrete piles, and cast-in-place concrete piles are used to support the structure. . These piles are originally intended to support the weight of the structure during normal times, but since many cases of pile damage have been reported in past earthquakes, it is important to improve the seismic performance of the pile foundation in terms of seismic design. It has been pointed out as an issue.
[0003]
The most common method for improving the seismic performance of piles is the seismic stress (= bending moment and horizontal shear) generated in the pile body due to forced deformation caused by horizontal force transmitted by the structure or horizontal displacement of the surrounding layer of the pile. This is a method of increasing the horizontal strength (= bending strength and shear strength) of the pile body so that it can withstand the force. In Japan, various methods for increasing the horizontal strength of pile bodies have been developed and put into practical use for many years.
[0004]
The conventional method for increasing the horizontal strength of piles is based on the assumption that the pile body is fixed to the upper structure or foundation footing by a rigid connection so as to constrain the rotational displacement of the pile head. It is said. However, in order to restrain the rotation of the pile head, a large bending moment and shear force are generated at the pile head.
[0005]
As a method to eliminate this unreasonableness, if the joint condition of this pile head is changed from "Pile head fixed" to "Pile head pin joint", "Semi-rigid joint" or "Elastic rotary spring joint", it will occur at the pile head It has been conventionally known that the stress during earthquakes is theoretically relieved greatly.
[0006]
In recent years, several attempts have been made to realize this pile head pin joint in the wake of the Great Hanshin Awaji Earthquake. The pile head joining methods that have been put to practical use are as follows: (1) Introducing a ball seat on the pile head to make a rotating pin joint, (2) Sliding support between the pile head and the foundation bottom , (3) Those trying to join a rotary spring with an elastic material such as rubber in the pile head, (4) Lowering the bending rigidity by making the pile head smaller than the pile shaft, and plasticity of the part There are some that try to limit the generation of bending stress by permitting the deformation and damage.
[0007]
[Problems to be solved by the invention]
The present invention is a “pile body” capable of “reasonably and economically” realizing “pile head pin joint” or “pile head rotation spring joint” that can greatly reduce the stress at the time of an earthquake occurring in a pile body, particularly a pile head. The main subject is to provide a “joining method between the head and its upper structure or basic footing”.
[0008]
In addition, because it is a practical joining method, it can be “simple and quick in construction”, it is a low-cost and economical method, and it can be applied to both ready-made piles and cast-in-place concrete piles. It is an important condition that it is a “joining method”.
[0009]
In particular, the present invention makes it an important subject to realize a joining method that overcomes and solves the problems and weaknesses of each of the existing pile head pin joining methods developed so far described in the above-described conventional technology. Since the problems differ depending on the individual construction methods, the problems and solutions of the methods (1) to (4) will be described below.
[0010]
[Means for Solving the Problems]
The present invention adopts the following configuration in order to solve the above points.
<Configuration 1>
It is a pile head joining device arranged between the head of the pile body that supports the structure and the foundation footing of the structure or structure, and has an outer peripheral flat plate portion that transmits a vertical load on the upper surface of the pile body, The pile side joining member A which has the recessed part which becomes the concave load receiving part which the inner side became depressed in the shape of a mortar, and it arrange | positions above the said pile side joining member A, and touches the center upper surface of the recessed part of the said pile side joining member A concerned. Consists of a base-side joining member B consisting of a convex part and a flat plate part that is present on the upper surface and joined to the upper foundation footing, and the contact surfaces of both the pile-side joining member A and the foundation-side joining member B , The curvature radius of the concave portion of the pile-side joining member A is larger than the curvature radius of the convex portion of the foundation-side joining member B, and the periphery of the convex portion of the foundation-side joining member B and the concave portion of the pile-side joining member A A gap is secured between the inner walls. Body head and joining apparatus of the structure.
[0011]
<Configuration 2>
It is a pile head joint device arranged between the head of the pile body that supports the structure and the foundation footing of the structure or structure, and has an outer peripheral flat plate portion that transmits a vertical load on the upper surface of the pile body, The pile-side joining member A having a convex portion protruding convexly on the upper side, and a downward concave load transmitting portion that is disposed on the upper side of the pile-side joining member A and covers the convex portion of the pile-side joining member A The pile-side joining member A and the foundation-side joining member B are both composed of a flat plate portion that is present on the upper surface and joined to the upper foundation footing. The curvature radius of the concave portion of the foundation-side joining member B is larger than the curvature radius of the convex portion of the pile-side joining member A, and the convex portion of the pile-side joining member A There is a gap between the periphery and the inner wall surface of the concave portion of the base side joining member B Bonding apparatus of Kuitai head and the structure, characterized in that it is holding.
[0012]
<Configuration 3>
In the pile head joining apparatus according to Configuration 1 or Configuration 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 substantially flat (curvature radius≈infinite In the range, the convex portion can be displaced in the horizontal direction with respect to the concave portion, and the pile side joining member A and the foundation side joining member B are relatively inclined and horizontally deformed. A device for joining a pile head and a structure, which is deformable.
[0013]
<Configuration 4>
In the pile head joining apparatus according to any one of the above-described configurations 1 to 3, the contact surfaces of the pile-side joining member A and the foundation-side joining member B are both in the vicinity of the center of the center contact portion of the convex portion and the concave portion. There is a tip fitting portion made of small irregularities for limiting positional deviation, and the pile side joint is provided between the periphery of the convex portion of the tip fitting portion and the inner wall surface of the concave portion of the tip fitting portion. A joining apparatus for a pile body head and a structure, wherein the member A and the foundation-side joining member B have a slight gap that can be relatively inclined and deformed.
[0014]
<Configuration 5>
In the pile head joining device according to any one of the above configurations 1 to 3, the displacement at the center contact portion in the pile side joining member A and the foundation side joining member B reaches a certain value or more, 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 convex peripheral wall and the concave inner wall surface of both the pile-side joining member A and the foundation-side joining member B are A joint device between a pile body head and a structure, wherein a gap between both the pile-side joining member A and the foundation-side joining member B is set so as to come into contact.
[0015]
<Configuration 6>
In the pile head joining device according to any one of the above configurations 1 to 3, of the gaps between both the pile side joining member A and the foundation side joining member B, the pile side joining member A and the foundation side joining member B both. The peripheral gap in the vicinity of the central contact portion is small, and when the central contact portion is displaced by a predetermined value 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 the pile body head to the structure.
[0016]
<Configuration 7>
In the pile head joining apparatus according to any one of the above-described configurations 1 to 3, the contact surfaces near the center contact portions of the pile side joining member A and the foundation side joining member B, or the concave and convex portions face each other. A lubricating liquid coating layer, a rust preventive liquid coating layer, a lubricating liquid filling portion, a rust preventing liquid filling portion, a solid lubricant film, or an elastic material is interposed on the peripheral wall surface. A device for joining the head of the pile body and the structure.
[0017]
<Configuration 8>
In the pile head joining apparatus according to any one of the above configurations 1 to 3, a foam material or a foam material or a backfill soil around the pile head is not mixed in a gap between the pile side joining member A and the foundation side joining member B. A coupling device for a pile body head and a structure characterized by being filled with a sponge-like substance.
[0018]
<Configuration 9>
In the pile head joining device according to any one of the above-described configurations 1 to 3, the gap between the pile side joining member A and the foundation side joining member B, or the peripheral flat plate portion of the pile side joining member and the foundation side joining member at the top thereof. An elastic material is disposed between them, and a restoring force for the relative displacement and inclination of the pile-side joining member A and the foundation-side joining member B is given, and at the same time as an elastic spring joint for horizontal deformation and rotational deformation of the pile head, An apparatus for joining a pile head and a structure, characterized by preventing backfilling soil around the apparatus from being mixed.
[0019]
<Configuration 10>
In the pile head joining device according to any one of the above-described configurations 1 to 3, a stud bolt joined by welding, a stud bolt joined by screwing, or an upper foundation footing joined to the upper surface of the joining flat plate on the foundation side joining member B. It has a protrusion fixed on the side, and the connecting plate and the upper structure can be connected and integrated by placing a concrete of the foundation of the structure on the upper part of the protrusion. To connect the pile head to the structure.
[0020]
<Configuration 11>
In the pile head joining apparatus described in the above configuration 1, the outer periphery of the concave portion of the pile side joining member A is slightly smaller than the inner diameter of the ready-made pile head, and a slight horizontal deviation occurs between the pile side joining member A and the pile body. Then, the pile body head and the structure joining device characterized by being capable of transmitting a horizontal shearing force in contact with the inner wall surface of the inside diameter of the pile body.
[0021]
<Configuration 12>
In the pile head joining apparatus described in the above configuration 2, a cylindrical insertion portion that is slightly smaller than the inner diameter of the pre-made pile head is provided at the lower part of the pile side joining member A, and between the pile side joining member A and the pile body. A device for joining a pile body head and a structure capable of transmitting a horizontal shearing force by contacting the inner wall surface of the inside diameter of the pile body when a slight horizontal deviation occurs.
[0022]
<Configuration 13>
The pile head joining apparatus according to any one of the above configurations 1 to 12, wherein the pile side joining member A and the foundation side joining member B are made of steel or casting, and the pile body head and structure Joining device with.
[0023]
<Configuration 14>
Using the pile head joining device according to any one of the above-described configurations 1 to 13, the outer peripheral diameter of the concave portion of the joining member A is slightly smaller than the inner diameter of the steel pipe-made ready-made pile, Inserted into the inner surface of the upper end that has been cut after installation, if the level of pile-side joining member A can be set below a certain value, leave it as is, and if the level of pile-side joining member A cannot be kept below a certain value, pile side A method for installing a pile head joining device on a steel pipe pile, wherein the pile body and the pile side joining member A are welded and joined while the joining member A is kept horizontal.
[0024]
<Configuration 15>
When the pile head joining device according to any one of the above configurations 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, and the level of the pile-side joining member A can be set to a certain value or less. If the horizontality of the pile-side joining member A cannot be secured below a certain value, the pile-side joining member A is inserted into the inner surface of the upper end of the pile after the upper surface of the pile body is repaired horizontally with a curable material. The installation method to the concrete-type ready-made pile of the characteristic pile head joining apparatus.
[0025]
<Configuration 16>
The entire pile head joining device according to any one of the above-described configurations 1 to 13, or only the pile-side joining member A, or a cylindrical member slightly larger than the outer peripheral diameter of the concave portion of the pile-side joining member A is used for concrete casting of cast-in-place concrete piles. A method for installing a pile head joining apparatus on a cast-in-place concrete pile, wherein the pile body concrete is placed at a predetermined position before installation, pile concrete is placed, and the remaining part B or the whole is inserted and installed after curing.
[0026]
<Configuration 17>
The entire pile head joining apparatus according to any one of the above-described configurations 1 to 13 or only the pile side joining member A is installed at a predetermined position after the concrete casting of the cast-in-place concrete pile, and the periphery of the pile side joining member A Post-placed anchor bolts are installed in the anchor bolt hole positions on the flat plate part to fix the pile head joining device, and a sponge-like material such as foamed polystyrene or foamed urethane is placed around it and the foundation is placed above it. A method of installing a pile head joining device on a cast-in-place concrete pile, characterized by placing side concrete.
<Overview>
First, the pile head pin joining method (Fig. 1) in which the ball seat is introduced into the pile head of the above existing method (1) is to support a large load relatively easily 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 ball seat, both concave and convex spherical surfaces having the same radius of curvature are in contact with each other, and the radius of curvature is usually around 10 cm and does not exceed several tens of cm at most. On the other hand, the deformation of the pile at the time of the earthquake causes the slope to be dragged by the horizontal shear displacement of the formation, so the rotation center position near the pile head is 2-3 m below the pile head (curvature radius ≈ 2-3 m) It is often a few meters below (curvature radius ≈ several m) or more, and the position varies depending on the combination of pile and ground conditions and the earthquake motion.
[0027]
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 the pin joint using the ball seat, as shown in FIG. 2, the rotation center of the ball seat and the rotation center of the pile inclination do not coincide with each other. An open discrepancy occurs. As a result, there is a possibility that a very large frictional force is generated, a foreign matter is mixed into a spherical surface with a gap between them and the ball seat function is impaired, or the ball seat itself may be damaged in some cases.
[0028]
In order to eliminate this drawback, it is necessary to abandon the basic mechanism of the ball seat called surface contact with the same curvature. That is, the present invention negates the conventional surface contact condition of the ball seat and establishes the point contact condition. Point contact without an area does not actually exist, but the point is to establish the point contact condition at the pile head joint position when the inclined deformation state of the pile is viewed macroscopically. For this purpose, the concave and convex two members are provided on both the pile side joining member and the foundation side joining member, and the curvature radius on the concave side is set larger than the curvature radius on the convex side on the contact surface. And a clearance gap is ensured around the convex member a little away from the contact part of both. By these two conditions, the convex pile material having a small curvature radius can be freely inclined with respect to the concave material, and as a result, the point contact condition is established. Since the curvature radii of both the unevenness are originally different, the pile material can be smoothly tilted and rotated independently of the rotation center position of the pile material.
[0029]
Next, the method of sliding support between the pile head and the foundation bottom in the existing method (2) has a fatal defect. That is, as shown in FIG. 3, since the pile material itself is inclined, the sliding surface of the pile head itself is also inclined, and the sliding surface side of the foundation bottom is rotationally restrained by the underground beam. A gap due to an inclination is generated on the contact surface of the contact surface and a normal sliding surface mechanism is not established. In addition, there is a claim that this mechanism can also be expected to have a seismic isolation effect due to slipping, but the base bottom itself is buried in the ground and the ground and structure (foundation) are integrated, but the seismic isolation effect The claim of expecting has a fundamental contradiction.
[0030]
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 of not transmitting all of the earthquake inertia force generated on the building side to the pile, but allowing the seismic force in the building to flow as much as possible to the ground side. This is a new point of view that was not found in the conventional design concept of pile foundations, and the present invention incorporates slip = "deviation" that incorporates only its advantages. However, if this deviation becomes excessive, a Pδ moment due to the deviation is added to the pile, so that the deviation is limited to a small value. In addition, the present invention is configured such that both contact surfaces are curved surfaces having different radii of curvature so that the slip condition is not disturbed by the relative inclination of the contact surface, and the slipperable region is limited to a slight range. is doing. This is configuration 3.
[0031]
Two types have been put to practical use so far in which an elastic material such as rubber is interposed between the pile heads of the existing method (3) to join a rotary spring. One is to enclose a ring-shaped rubber body in the groove, and this has a drawback that its engagement mechanism is easily disengaged by rotation or pulling force. The other uses a laminated rubber body in which one or two to three thin rubber layers are vulcanized and bonded to a steel plate. There is no mechanical defect at all and the rotational elastic spring is ideal for mechanical performance. Bonding is realized. If we dare to raise the weak point of this method, the use surface pressure of the working load is limited because of the use of a rubber material, and the manufacturing area is increased to some extent because the device area is increased.
[0032]
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 is supported by the contact of the steel material of both the concavo-convex members to ensure a large load support capability, and a rubber body is interposed in the gap between the concavo-convex both joints to obtain an elastic restoring force, The solution is to obtain an elastic restoring force. As a result, the present invention has made it possible to economically realize “elastic rotation spring joining” even for large vertical loads.
[0033]
For the existing method (4), the pile head is made smaller than the pile shaft, the bending rigidity is lowered, the plasticity and damage of the part is allowed, and the generation of bending stress is restricted. Although the idea of “allowing plasticization and damage of the part” can be reduced in cost, it 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 forgot its purpose. This contradicts the original idea, and once damaged, it cannot be repaired, so this method must be said to be an extremely incomplete solution. Therefore, the present invention denies such a solution and does not adopt it.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments.
[0035]
FIG. 1 is a basic configuration diagram of a pile head pin joint using a conventional ball seat, and FIG. 2 is an explanatory diagram showing that the basic mechanism is destroyed during an earthquake. As shown in Fig. 2 (2), the rotation of the upper foundation footing is constrained by underground beams, and the pile side tilts during an earthquake, so the rotation center of the ball seat and the rotation center of the pile head do not match, This ball seat system has a fatal defect on the basic principle.
[0036]
FIG. 3 is an explanatory diagram showing that the basic mechanism is not normally established even in the case of a pile head slide joint using a conventional slide bearing (in some cases, a wrong name is used as a pile head roller joint). is there. Fig. 3 (1) shows the case where the sliding plate is on the pile side, and Fig. 3 (2) shows the case where the sliding plate is on the foundation footing side. The normal sliding surface contact condition is not established. In addition, the eccentric moment Pδ (P is the applied vertical load) acts on the pile due to this slip amount δ, so if the slip amount is excessive, a large moment that far exceeds the moment that can be released by pin joining acts on the pile head. I will let you.
[0037]
FIG. 4 shows the basic configuration of the present joining apparatus defined in Configuration 1. FIG. 4 (1) applies to steel pipe piles, and FIG. 4 (2) applies to concrete-based ready-made piles including steel pipe coverings. When doing, FIG.4 (3) has illustrated about the case where it applies to a cast-in-place concrete pile.
[0038]
FIG. 5 shows the basic configuration of configuration 2 in which the concavo-convex configuration is turned upside down. FIG. 5 (1) is applied to a steel pipe pile, and FIG. 5 (2) is a concrete ready-made pile including a steel pipe coating. In the case of application, FIG. 5 (3) illustrates the case of application to a cast-in-place concrete pile.
[0039]
FIG. 6 illustrates the basic principle of the present joining apparatus. FIG. 6 (1) shows the case of configurations 1 and 4, and FIG. 6 (2) shows the case of configurations 2 and 5. FIG. The former (Configuration 1 / FIG. 4) is configured to bear the load on the pile-side joining member A in a tensile stress state, and the latter (Configuration 2 / FIG. 5) is configured to load the pile-side joining member A in a compressive stress state. It is configured to bear the load.
[0040]
Both AB members have a sufficiently safe member cross-section to bear the supporting load, but this member is usually made of a cast material such as steel or ductile cast iron, so that the tip cross-sectional area of the convex member is substantially equal to the pile shaft cross-section. Therefore, it can be reduced to a point contact. In addition, the concave and convex members are freely inclined and deformed by forming the tip of the convex member as a smooth curved surface, and forming the concave side in contact with this as a tray with a curved surface having a larger curvature radius, and securing a gap around it. Is possible. FIG. 6 (3) shows a method of constructing a curved surface on the contact surface between the concave and convex members.
[0041]
When the pile material inclines during an earthquake, the convex member of this device inclines around the tip contact part (= rolls), and does not perform rotational movement due to sliding of the contact surface unlike conventional ball seat bearings. . In the sliding motion of a spherical surface, the sliding friction is generated and becomes a large resistance force. However, in this device, the basic motion mechanism is not a sliding motion but a rolling rotational motion of the contact surface. Does not occur.
[0042]
FIG. 7A shows a case where a small uneven 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 that the fitting portion has a sufficient space so that the fitting deformation portion of the fitting portion does not hinder the inclined deformation of the fitting portion. This is the content of Configuration 4.
[0043]
Moreover, since this contact part is basically a rolling motion as described above, the horizontal resistance force 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 concave and convex portion of the tip, and in order to transmit a large horizontal shearing force to the pile, a gap between both the convex member and the concave member is appropriately set. The shape is set so that the two come into contact with each other at a certain slope or more and the apparatus can exhibit a sufficient shear strength. This is the content of Configuration 5.
[0044]
In order to prevent the horizontal position deviation in the vicinity of the contact portions of both the concavo-convex members and at the same time reliably transmit the horizontal shearing force, it is certain that the gap near the tip of the convex member is made small. For this purpose, FIG. 7B shows a configuration 6 in which a slip prevention projection is formed on the concave side.
[0045]
The above shows a method of configuring a pin joining mechanism by point contact of both AB members.
[0046]
As described in the explanation of the existing method (2), as the pile head joining method, by combining this pin joining method with “slight slip area”, without adding excessive Pδ moment to the pile, It is possible to transmit more earthquake inertia force directly to the ground side. In order to configure the slip region, a radius of curvature of the contact portion on the recess material side is increased and brought close to a flat plate, and a stopper projection for limiting excessive slip is configured. FIG. 7 (3) shows an example of the configuration, which is a configuration in which the configuration 3 and the configuration 6 are combined.
[0047]
In FIG. 7 (3), the direction where there is little frictional resistance of the contact part of AB both members can generate a smoother slip, and can reduce the horizontal transmission force to a pile. Configuration 7 shows a method for improving the lubrication performance of the contact portion, which is the most important part in the present joining device, and also taking measures to prevent rust on the surface of the contact surface and the concave and convex members (the inner surface side of the concave portion). Is. As a method that can satisfy both the functions of lubrication and rust prevention, the inside of the recess material is filled with lubrication / rust prevention liquid such as grease, oil, rust prevention oil, viscous fluid, etc., 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 the gap and the contact surface.
[0048]
This joining device is usually placed on the pile head and backfilled in the soil. At this time, if the backfill soil, gravel or sand from the cracking ground industry, or discarded concrete is mixed in the gap between the joining members AB, the deformation performance of the joining device may be killed. In order to prevent this loss of function and to ensure the reliable operation of the present apparatus, a gap between both the joining members AB is filled with a sponge-like material such as urethane foam or polystyrene foam as shown in FIGS. This is configuration 8. These members are sufficient to prevent the backfill soil and the like from being mixed, but they are extremely soft materials and do not affect the operation of the apparatus during an earthquake.
[0049]
Since this joining apparatus is a point contact mechanism of both concavo-convex members, rotational deformation is extremely easy and hardly generates a resistance force. As a method of giving an elastic restoring force to the present joining apparatus, a rubber body is interposed in the gap between the AB portions of the peripheral portion of the present joining apparatus as shown in Configuration 9 and FIG. 9, and the restoring force is given by elastic deformation thereof. it can. Further, as shown in the lower part of FIG. 9 (2), the entire gap between the AB members can be filled with an elastic material to give both restoring force and rust prevention performance. In the present apparatus, the vertical load is transmitted by direct contact between both the concavo-convex members, and it is not necessary to bear the vertical load with the rubber body, so that it is easy to adjust the restoring spring performance. The rubber body also functions to prevent backfilling soil and the like from being mixed into the gap between the two ABs.
[0050]
Configuration 10 and FIG. 8 relate to a method of joining the present joining apparatus and the upper foundation concrete. In this joining apparatus, a stud bolt is attached to the upper surface of the flat plate by welding or screwing. In addition, as shown in FIG. 8, a method of driving a fixing protrusion into the basic footing is also effective as a fixing function of the convex portion. Since the upper foundation and the apparatus can be integrated by simply placing the foundation concrete on the upper part of the joining member B having the stud bolts and fixing protrusions prepared in advance, the installation work is simple and quick.
[0051]
Configurations 11 and 12 relate to a method of joining the pile body and the main joining device when the ready-made pile is a target. As shown in FIGS. 4, 5, and 8, the lower part of the device is slightly less than the inner diameter of the pile head. The installation of the apparatus is completed simply by reducing the size and inserting the apparatus into the inner cylindrical portion of the pile head. The insertion depth of this apparatus is usually about 10 cm or more so that this apparatus does not come out of the pile even if there is an action of vertical movement. Originally, this device does not resist lifting and does not transmit tensile force to the pile material.
[0052]
The configuration 13 defines the constituent material of the main joining member AB of the present joining apparatus, and is manufactured from a steel material or a casting (cast iron). In particular, the uneven shape of the present apparatus is suitable for casting, and ductile cast iron is a typical material.
[0053]
Configurations 14 to 17 prescribe the installation method and construction method of the present joining apparatus. Structure 14 and FIG. 10 have shown the installation method of this joining apparatus with respect to a steel pipe pile. If the pile head after the steel pipe pile can be driven to the specified height and the pile inclination angle is not large (normally, inclination angle ≤ 1/100 rad), this joining device is connected to the pile head of the steel pipe pile. Just insert it inside.
When the slope of the steel pipe pile is large and when the steel pipe pile head is gas-cut after driving the pile, as shown in Fig. 10, the device is inserted inside the pile head and the device is kept in a horizontal state. The pile and this device are welded together. By this method, even when the steel pipe pile is inclined or the cut surface of the pile head is disturbed by gas cutting, this joining device is installed horizontally and the vertical load is transmitted normally to the pile. Pile can be protected as a pile head pin joint.
[0054]
Structure 15 and FIG. 11 have shown the installation method of this joining apparatus with respect to the concrete-type ready-made pile containing a steel pipe covering. When the pile after placing is driven vertically, it is only necessary to insert this joining device into the pile head.
If the inclination angle of the pile is large (usually inclination angle> 1/100 rad), repair the upper surface of the pile horizontally with epoxy resin or high-strength mortar, etc., and install this device after the strength is developed.
[0055]
Configurations 16 and 17 show the installation method of the present joining apparatus for cast-in-place concrete piles. Configuration 16 and FIG. 12 are construction methods in the case where the central portion of the joining member A protrudes in a concave shape, and as shown in FIG. 12 (1), the entire joining device or joining is performed before casting the cast-in-place concrete pile. This is a method of placing the concrete of the pile after attaching the member A at a predetermined position or attaching a cylindrical member into which the central portion of the joining member A can be inserted as shown in FIG.
If the method of attaching the device before the concrete is not used, in order to attach the device in which the bottom of the joining member A is convex downward, it is necessary to make a hole in the pile head concrete. It will take a lot of time and effort.
[0056]
Configuration 17 and Fig. 13 are construction methods for installing a device with a flat bottom of the joining member A. As shown in Fig. 13 (1), the installation position of this device is leveled flat after the cast-in-place concrete pile is hardened. Then, the apparatus is horizontally installed on a thin mortar or the like, and then the anchor bolt is post-placed (FIG. 13 (2)). In the case of cast-in-place concrete piles, this joining device can be easily installed at a predetermined position by this method, and then, as shown in FIG. 13 (3), soft cushioning such as polystyrene foam or urethane foam around the device. All you need to do is lay the material and place the foundation concrete on the top.
[0057]
【The invention's effect】
As described above, when the pile head joining device of the present invention is adopted, the following effects can be obtained in joining the pile body and the structure or the foundation footing, and also advantageous conditions for the existing pile head pin joining method Can be realized.
(1) The joint condition between the pile head and the foundation footing can be almost perfect pin joining.
(2) Further, the pile head can be made into an elastic rotary spring joint having an appropriate restoring force.
(3) 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.
(4) As a result, it is possible to remarkably reduce the earthquake stress generated in the pile body head, and to dramatically improve the seismic safety performance of the pile body.
(5) Since the stress generated by the earthquake at the pile head is drastically reduced, the cross section of the underground beam can be reduced. As a result, the foundation bottom is shallow, the amount of excavated soil is reduced, and the entire foundation work is reduced. Cost is greatly reduced.
{Circle around (6)} The present joining apparatus can cope with a vertical support load from a small load of 10 tons / piece or less to a large load of 1000 tons / piece or more.
(7) This joining apparatus can be applied to all types of piles including small-diameter steel pipe piles, ready-made concrete piles, steel pipe-covered concrete piles (SC piles), and cast-in-place concrete piles.
(8) It has good workability for all types of piles, and construction in a very short construction period is possible.
Specifically, after construction of the pile body, the construction is completed simply by installing this device on the pile head and placing the foundation footing or concrete of the structure on the top of the pile body. Can do.
(9) The joining members A and B of this joining device are suitable for casting, can be manufactured at low cost, and have good workability. It is a joining method.
[0058]
As described above, the present invention makes it possible to quickly construct a pile head pin joint, a slight slip-combined pin joint, and an elastic rotary spring joint that can greatly reduce the stress of a pile body during an earthquake with a simple construction method. It is a thing. Moreover, since it can be applied to all types of piles from small loads to large loads and can be supplied at low cost, the utility of the present invention is extremely high, and a pile foundation structure with excellent seismic safety performance is economical. It is possible to realize.
[Brief description of the drawings]
FIG. 1 Basic configuration diagram of a conventional pile head pin joining device using a ball seat
FIG. 2 is a diagram for explaining a malfunction of a conventional pile head pin joining device using a ball seat.
(1) Earthquake deformation state of piles under the building
(2) Illustration of the principle that the center of curvature of the ball seat and the center of rotation of the pile do not coincide near the pile head
[Fig. 3] Explanatory diagram of conventional pile head sliding (roller) joint using sliding bearing
(1) Deformation state during earthquake when slip plate is installed on the pile side (lower side)
(2) Deformation state during an earthquake when the sliding plate is installed on the foundation footing side (upper side)
FIG. 4 is an explanatory diagram of a cross-sectional configuration of a pile head joining device according to the present invention (when a concave load receiving portion is arranged on the lower side (pile side)).
(1) Device cross-sectional configuration example when applied to steel pipe piles
(2) Example when applied to concrete-based ready-made piles (including SC piles)
(3) Example of application 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) Device cross-sectional configuration example when applied to steel pipe piles
(2) Example when applied to concrete-based ready-made piles (including SC piles)
(3) Example of application to cast-in-place concrete piles
FIG. 6 is a mechanism explanatory diagram of the operating principle of the device of the present invention.
(1) When placing the concave load receiving part on the lower side (pile side)
(2) When placing the concave load receiving part on the upper side (foundation footing side)
(3) Curvature composition explanatory drawing of a concavo-convex member contact part
FIG. 7 is an explanatory diagram of the configuration around the contact portion of both concave and convex members.
(1) When a tip fitting part is provided in the center of the contact part
(2) When a protrusion for preventing misalignment is provided on the concave material side near the tip of the convex member
(3) A slip area is formed at the contact portion,
When the protrusion for preventing misalignment of (2) above is provided on the outer concave material
FIG. 8 is a diagram illustrating the structure of a member for joining a pile and a foundation.
(1) In the case of steel pipe piles
(2) For concrete ready-made piles (including SC piles)
(3) For cast-in-place concrete piles
FIG. 9 shows an example of a configuration method for applying a restoring force of a rotary elastic spring by an elastic material such as rubber.
(1) In the case of steel pipe piles
(2) For concrete ready-made piles (including SC piles)
(3) For cast-in-place concrete piles
[Fig. 10] Explanatory drawing of construction method when installing this joining device on steel pipe pile
(1) Cutting steel pipe pile heads and suspending equipment
(2) On-site welding and suspension bolt removal with the device held in place
(3) Installation state of the device protruding upward
[Fig. 11] Explanatory drawing of construction method when installing this joining device on concrete-based ready-made piles (including SC piles)
(1) Suspension of this joining device
(2) After installing this equipment, remove the suspension bolts and place the upper foundation concrete.
[Fig. 12] Explanatory drawing of the construction method when installing this joining device on cast-in-place concrete piles (in the case of the device with the recessed material protruding downward)
(1) A method of placing pile concrete after placing the lower recess material or the entire device at a predetermined position and fixing it with a reinforcing bar or temporary member.
(2) A cylindrical member capable of inserting and installing the lower concave member later is attached before pile concrete placement, and pile concrete placement is performed. Construction method to install this device later
(3) Method of inserting and installing this apparatus in the same cylindrical member as above and fixing by grouting
[Fig. 13] Explanatory drawing of construction method when installing this joining device on cast-in-place concrete pile (in the case of equipment with concave material on the upper side)
(1) The cast-in-place concrete is constructed as usual, and after placing the pile concrete, the device installation position is leveled and the device member A (lower side) is suspended.
(2) The apparatus member A is installed and an anchor bolt is post-placed on site.
(3) Suspend and install this device member B (upper side), and after placing protective materials that prevent both upper and lower concrete interference such as foamed polystyrene and backfill soil around it, the foundation concrete above the device is To cast.
[Explanation of symbols]
1: Building or superstructure
10: Basic footing
11: Underground beam
2: Pile
21: Steel pipe pile
22: Ready-made concrete piles (including SC piles)
23: Cast-in-place concrete pile
24: Pile rebar basket
3: Pile head pin joining device using ball seat
3A: Pile side member
3B: Basic footing side member
31: Contact sliding surface of the ball seat
4: Pile head joining device by sliding support
41: Sliding board
42: Sliding surface support member
5: Pile head joining device of the present invention (when the concave member is on the pile side (lower side))
5A: Pile side joint member (concave member)
5B: Foundation side joining member (convex type member)
5C: gap filling cushioning material
5D: Elastic body for restoring force (rubber body)
51: Recessed material side contact surface
52: Sliding clearance
53: Protrusion for stopper
54: Flat plate for foundation side fixing
55: Stud bolt
56: Fixing protrusion
57: Hanging bolt for installation
58: Cylindrical driving frame
59: grout wood
6: Pile head joining device of the present invention (when the concave member is on the foundation footing side (lower side))
6A: Pile side joint member (convex member)
6B: Foundation side joining member (concave member)
6C: Gap filling cushioning material
6D: Elastic body for restoring force (rubber body)
61: Contact surface on recess side
64: Flat plate for fixing on the foundation side
65: Stud bolt
66: Anchor bolt

Claims (16)

A pile head joining device arranged between the head of the pile body that supports the structure and the structure or the foundation footing of the structure,
A pile-side joining member A having an outer peripheral flat plate portion for transmitting a vertical load on the upper surface of the pile body, and having a concave portion that is a concave load receiving portion whose inside is recessed in a mortar shape,
The foundation side joining member which consists of the convex part which is arrange | positioned above the said pile side joining member A, touches the center upper surface of the recessed part of the said pile side joining member A, and exists in the upper surface, and is joined to an upper foundation footing. B,
In the contact surfaces of both the pile-side joining member A and the foundation-side joining member B, the curvature radius of the concave portion of the pile-side joining member A is larger than the curvature radius of the convex portion of the foundation-side joining member B, and the foundation A gap is secured between the periphery of the convex portion of the side joining member B and the inner wall surface of the concave portion of the pile side joining member A,
An apparatus for joining a pile body head and a structure , wherein a gap between the pile side joining member A and the foundation side joining member B is filled with a foam material or a sponge-like substance . A pile head joining device arranged between the head of the pile body that supports the structure and the structure or the foundation footing of the structure,
A pile-side joining member A having an outer peripheral flat plate portion for transmitting a vertical load on the upper surface of the pile body, and having a convex portion with a central portion projecting upward.
Arranged on the upper side of the pile-side joining member A, has a concave portion serving as a downward concave load transmitting portion covering the convex portion of the pile-side joining member A, and is present on the upper surface and joined to the upper foundation footing. Composed of a base-side joining member B composed of a flat plate portion,
The pile-side joining member A and the foundation-side joining member B are in contact with each other at the center of the plane, and the curvature radius of the concave portion of the foundation-side joining member B is the curvature radius of the convex portion of the pile-side joining member A at the contact surface. Larger than that, 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,
An apparatus for joining a pile body head and a structure , wherein a gap between the pile side joining member A and the foundation side joining member B is filled with a foam material or a sponge-like substance . In the pile head joining apparatus according to claim 1 or 2,
In the contact surface of the pile-side joining member A and the foundation-side joining member B, the vicinity of the central contact portion of the convex portion and the concave portion is substantially flat (curvature radius≈infinity), and the convex portion is a concave portion within the range. It is possible to shift horizontally with respect to
The said pile side joining member A and the foundation side joining member B can carry out the inclination deformation | transformation and horizontal deformation | transformation relatively, The joining apparatus of the pile body head and structure characterized by the above-mentioned. In the pile head joining apparatus according to any one of claims 1 to 3,
At the contact surface of the pile-side joining member A and the foundation-side joining member B, a tip fitting portion made of small irregularities for limiting the deviation of the planar positional relationship between the convex portion and the central contact portion of the concave portion. The pile-side joining member A and the foundation-side joining member B can be slightly inclined and deformed between the periphery of the convex portion of the tip fitting portion and the inner wall surface of the concave portion of the tip fitting portion. An apparatus for joining a pile body head and a structure characterized by having a gap of In the pile head joining apparatus according to any one of claims 1 to 3,
The displacement at the central contact portion in the pile side joining member A and the foundation side joining member B reaches a certain value or more, or
When the relative inclination angle between the pile-side joining member A and the foundation-side joining member B reaches a certain value or more,
The convex peripheral wall and the concave inner wall surface of both the pile side joining member A and the foundation side joining member B are in contact with each other.
A joint device between a pile body head and a structure, wherein a gap between both the pile-side joining member A and the foundation-side joining member B is set. In the pile head joining apparatus according to any one of claims 1 to 3,
In the vicinity of the center contact portion of both the pile-side joining member A and the foundation-side joining member B, a protrusion that protrudes toward the convex side is provided on the concave side.
When the central contact portion is displaced by a certain value or more, only the vicinity of the tip of the convex portion is set so as to come into contact with the protruding portion on the concave portion side, and the pile body head and the structure, Welding equipment.  The pile head joining apparatus according to any one of claims 1 to 3, wherein the vicinity of the contact surface of the center contact portion of both the pile side joining member A and the foundation side joining member B, or the relative surface of the concave portion and the convex portion. A lubricating liquid coating layer, a rust preventive liquid coating layer, a lubricating liquid filling portion, a rust preventing liquid filling portion, a solid lubricant film, or an elastic material is interposed on the peripheral wall surface A device for joining a pile body head and a structure characterized by the above. In the pile head joining apparatus according to any one of claims 1 to 3,
Between the pile-side joining member A and the foundation-side joining member B, or between the surrounding flat plate portion of the pile-side joining member and the foundation-side joining member at the upper part thereof , the relative of the pile-side joining member A and the foundation-side joining member B It is characterized by the elastic elastic body that gives the restoring force against the misalignment and inclination, and the elastic spring joint against the horizontal deformation and rotational deformation of the pile head and at the same time preventing the backfill soil around the device from mixing To connect the pile head to the structure. In the pile head joining apparatus according to any one of claims 1 to 3,
On the upper surface of the joining flat plate on the upper side of the base side joining member B, a stud bolt joined by welding, a stud bolt joined by screwing, or a protrusion fixed to the upper base footing side,
An apparatus for joining a pile head and a structure, wherein the joining flat plate and the upper structure can be connected and integrated by placing a concrete of the foundation of the structure on top of the protrusion. In the pile head joining apparatus according to claim 1,
The outer periphery of the concave portion of the pile-side joining member A is slightly smaller than the inner diameter of the ready-made pile head,
Pile body head and structure joining device characterized in that when a slight horizontal shift occurs between the pile side joining member A and the pile body, it can contact the inner wall surface of the inside diameter of the pile body and transmit a horizontal shearing force. . In the pile head joining apparatus according to claim 2,
A cylindrical insertion part slightly smaller than the inner diameter of the pre-made pile head is provided at the bottom of the pile-side joining member A,
Pile body head and structure joining device characterized in that when a slight horizontal shift occurs between the pile side joining member A and the pile body, it can contact the inner wall surface of the inside diameter of the pile body and transmit a horizontal shearing force. . In the pile head joining apparatus according to any one of claims 1 to 12 ,
The pile-side joining member A and the foundation-side joining member B are manufactured from steel materials or castings. Using the pile head joining device according to any one of claims 1 to 12 ,
The outer diameter of the concave portion of the joining member A is slightly smaller than the inner diameter of the steel pipe ready-made pile,
Insert the steel pipe pile on the inner surface of the upper end after casting or the upper end cut after casting,
When the level of pile-side joining member A can be set below a certain value, leave it as it is,
Pile head joining device, wherein the pile body and the pile side joining member A are welded and joined in a state where the pile side joining member A is kept horizontal when the level of the pile side joining member A cannot be secured below a certain value. Installation method for steel pipe piles. The pile head joining device according to any one of claims 1 to 12 ,
Insert into the inner surface of the upper end of ready-made concrete pile or steel pipe-covered ready-made concrete pile,
When the level of pile-side joining member A can be set below a certain value, leave it as it is,
When the level of pile-side joining member A cannot be secured below a certain value, after repairing the upper surface of the pile body horizontally with a curable material,
The pile side joining member A is inserted in the inner surface of the pile upper end, The installation method to the concrete type ready-made pile of the pile head joining apparatus characterized by the above-mentioned. The entire pile head joining device according to any one of claims 1 to 12 , or only the pile side joining member A, or a cylindrical member slightly larger than the outer peripheral diameter of the concave portion of the pile side joining member A,
Install in place before placing concrete in cast-in-place concrete piles,
A method for installing a pile head joining apparatus on a cast-in-place concrete pile, in which pile body concrete is placed and the remaining part B or the whole is inserted and installed after curing. The whole pile head joining device according to any one of claims 1 to 12 , or only the pile side joining member A,
Installed in place after the concrete placement of cast-in-place concrete piles,
Fix the pile head joining device by placing a post-placed anchor bolt in the field at the anchor bolt hole position provided in the peripheral plate part of the pile side joining member A,
A method for installing a pile head joining device on a cast-in-place concrete pile, characterized in that a sponge-like substance such as foamed polystyrene or urethane foam is placed around the base and concrete on the foundation side is placed thereon.

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