KR102650570B1 - Phc pile with shear groove and head reinforcement structure of phc pile using the same - Google Patents

Abstract

PHC piles equipped with shear grooves that can integrate PHC piles and expanded foundations by ensuring the bonding strength of PHC piles and filled concrete while cutting and constructing the PHC pile head according to changes in the stratum of the construction site, and PHC using the same A head reinforcement structure for a pile is disclosed. The PHC pile with the above shear groove and the head reinforcement structure of the PHC pile using it can shorten the construction period and significantly improve structural stability while ensuring the work safety of field workers, as well as stress on the head of the PHC pile and the expanded foundation concrete. Structural safety of structures such as buildings and bridges constructed using PHC piles by ensuring that the PHC pile head load acting on the filled concrete is not concentrated and is evenly transmitted to the entire PHC pile and transmitted to the high-quality bearing layer at the tip of the PHC pile. It has the effect of significantly improving.

Description

PHC piles with shear grooves and head reinforcement structure of PHC piles using the same {PHC PILE WITH SHEAR GROOVE AND HEAD REINFORCEMENT STRUCTURE OF PHC PILE USING THE SAME}

The present invention relates to a PHC pile having a shear groove and a head reinforcement structure of the PHC pile using the same. More specifically, the present invention relates to a PHC pile having a shear groove and a head reinforcement structure of the PHC pile using the same. More specifically, it can be used to reinforce the pile head of a PHC pile embedded in an excavation hole during foundation construction for urban building and civil engineering work. This relates to PHC piles with shear grooves and the head reinforcement structure of PHC piles using the same.

In general, in the process of constructing a structure or building such as architecture or civil engineering, piles are buried in a high-quality support layer and the structure or building is constructed on top of it to ensure stability and prevent subsidence.

Recently, with the introduction of construction and earthquake-resistant design methods in soft ground and coastal areas, PHC (Pretensioned spun high strength concrete, KS F 4306) piles are embedded vertically into the ground to ensure the stability of structures to reach a high-quality support layer. The pile method is currently being used.

The PHC pile as described above is a high-strength concrete pile made by the pretension method with a compressive strength of more than 80Mpa (N/mm ² ) of concrete manufactured by applying centrifugal force to form a cavity in the deep area, and is referred to as a general PHC pile.

On the other hand, a pile in which a PC steel bar and a reinforcing bar basket are embedded together in the PHC pile is called a PHC pile according to the specification, and a pile in which a transverse band or spiral reinforcing bar is wrapped around the PHC pile according to the specification is called a PRC pile.

The characteristics and shapes of the inner walls of general PHC piles, specification PHC piles, and PRC piles as described above are all formed the same. Typically, the three piles described above are called PHC piles, and such PHC piles carry the load of the pile head. It is used as a medium to deliver the high-quality bearing layer at the tip of the pile.

Meanwhile, in the case of superstructures installed on top of PHC piles such as bridges during earthquake loads, the rigidity of the PHC piles buried in the ground is used to suppress horizontal loads. At this time, the PHC piles and the superstructure are supported. The joint where the expanded foundation is joined is joined very strongly, exceeding the rigidity of the PHC pile, and this is called a strong joint.

Figure 1 is a drawing to explain a conventional general specification PHC pile and its construction process.

Referring to Figure 1, the components that strengthen the head of the PHC pile 300 by strongly coupling the joint between the PHC pile 300 and the expanded foundation 400 include the reinforcing bar 310 in the pile body and the main surface inside the PHC pile. It consists of filled concrete (320) and filled reinforcing bar (330) filled in the upper part. Here, the reinforcing bar (310) in the pile body embedded in the inside of the PHC pile (300) is connected to the PHC pile (300) and the expanded foundation. It refers to a reinforcing bar basket that strongly connects.

Here, the PHC pile 300 and the expanded foundation 400 are connected to each other by reinforcing bars 310 in the PHC pile body, so that the horizontal displacement of the bridge superstructure caused by horizontal loads such as earthquake load or wind load is resisted by the pile stiffness in the ground. Pile stiffness refers to the elastic modulus and secondary moment of inertia of the pile, and refers to the bending resistance of the pile.

As shown in Figure 1, looking at the construction process of the conventional PHC pile according to the specification, when manufacturing the PHC pile according to the specification, the reinforcing bar (330) and PC steel bar (340), which are rebar baskets, are purchased at the factory, and then the PC steel bar (340) is pre-stressed. After producing a high-strength concrete pile, the pile (300) is installed in the ground at the site, and the concrete at the head of the pile is crushed with a crusher to remove the reinforcing bar (330) and the PC steel bar (340) inside the pile body, which is a reinforcing bar basket, to the outside. After exposure, the exposed pile body reinforcing bars 330 and PC steel bars 340 are fixed to a certain length in the expanded foundation 400 and concrete is poured.

In the case of the PHC pile (300) with the above specifications, when the concrete at the head of the pile is crushed with a crusher, the prestress applied at the factory is released to a length of about 50 times the diameter of the PC steel bar (340), and the high-strength concrete becomes general reinforced concrete. There is a problem.

Therefore, in order to compensate for the lost head rigidity of the specification PHC pile (300), concrete is poured from the final fracture surface of the head of the specification PHC pile (300) to a depth of about 1 m into the hollow part of the specification PHC pile, which is filled with concrete (320). ).

In other words, filled concrete (320) refers to concrete poured at a certain depth in the hollow part of the head of the PHC pile (300) according to the specification, and such filled concrete (320) is filled in the hollow part of the head of the PHC pile (300) according to the specification. It has the function of reinforcing piles weakened by crushing the pile head.

As described above, the filled concrete (320) poured into the hollow part of the head of the specification PHC pile (300) is initially attached to the inner wall of the specification PHC pile (300), but over time, the drying shrinkage (volume reduction) of the concrete material characteristics decreases. ) is not only generated, but there is a problem that adhesion is lost due to the vibration of seismic load, the lubrication of the groundwater level, and the cement paste layer called the slippery and weak furnace layer of the inner wall of the PHC pile (300) according to the specifications.

Therefore, the specification PHC pile 300 and the expanded foundation 400 are required to integrate the specification PHC pile 300 and the expanded foundation 400 even if the adhesion of the filled concrete 320 is lost. In the case of the PHC pile (300), due to the nature of being made of concrete, the steel shear key cannot be welded to the inner wall of the pile like a steel pipe pile, so the adhesion between the filled concrete (320) and the inner wall of the specification PHC pile (300) is different from the material. Because it is destroyed by environmental conditions, there is a problem that a fixing point cannot be created using a shear key (non-slip bump) like a steel pipe pile.

In order to solve this problem, when manufacturing PHC piles according to specifications, the factory manufactures PHC piles according to specifications (300) by embedding reinforcing bars (310), which are rebar baskets, inside the PHC pile according to specifications, and then during construction of PHC piles according to specifications (300). According to the specifications, a method has been used to reinforce the head of the PHC pile (300) by exposing the reinforcing bar (310) in the pile body of the PHC pile (300) from concrete and anchoring it inside the expanded foundation (400).

However, in order to expose the reinforcing bars 310 and PC steel bars 340 in the specification PHC pile body, the concrete at the head of the specification PHC pile 300 must be crushed using mechanical devices such as a crusher, portable hammers, cutters, etc. At this time, not only do casualties frequently occur due to concrete fragments and the loosening of the PC steel rod 340, but there is also a problem in that it takes a very long time.

In addition, general PHC piles, which are widely used in buildings with low loads, often cause casualties due to the loosening of PC steel bars (340) when the concrete at the head of the pile is crushed or cut by man or machine, like the PHC pile (300) in the specification. There is a problem that it takes a very long time to crush concrete.

Figure 2 is a diagram for explaining the process of constructing an expanded foundation after cutting the head of a PHC pile with a single cut.

Referring to Figure 2, the fixation accuracy of the PHC pile 300 and the expanded foundation 400 is low, but for the safety of workers, the head of the PHC pile 300 is cut by circular cutting using a machine, and then the cut PHC pile is cut. A method of reinforcing the head of the PHC pile (300) is used by embedding the head of the PHC pile (300) in the expanded foundation (400) at a depth of 50 mm (buildings) to 100 mm (bridges). However, in this method, the PHC pile There is a problem in that the fixation accuracy is much lower compared to the method of exposing the internal reinforcing bar (310: see Figure 1) and embedding it in the expanded foundation 400, and if the adhesion of the filled concrete 320 is lost over time, Not only is there a problem that the fixation accuracy is further reduced, but there is also a problem that the concrete of the expanded foundation (400) around the head of the pile (300) embedded in the expanded foundation (400) is damaged.

Accordingly, as disclosed in Republic of Korea Patent Publication No. 10-0999020 (registration date December 1, 2010), a 'synthetic PHC' is formed by installing square reinforcing bars horizontally in the PHC pile body to form a non-slip ridge in the hollow part of the pile. Seed piles and synthetic PH pile construction methods' have been developed and are in use.

Such PHC piles have the problem that square horizontal reinforcing bars are factory-fabricated and installed only at the pile head, so if the support layer at the construction site is shallow, the square horizontal reinforcing bars must be cut. If the support layer at the site is deep, the square horizontal reinforcing bars are buried in the ground or piled. There is a problem that the pile tip must be installed in a stratum with insufficient bearing capacity.

Republic of Korea Patent Publication No. 10-0999020 (2010.12.01.) Republic of Korea Patent Publication No. 10-1515344 (April 21, 2015) Republic of Korea Patent Publication No. 10-1050458 (2011.07.13.) Republic of Korea Patent Publication No. 10-1414053 (2014.06.25.)

The purpose of the present invention is to construct a PHC pile with a shear groove that can integrate the PHC pile and the expanded foundation by reliably securing the adhesion strength of the PHC pile and the filled concrete while cutting and constructing the PHC pile head according to changes in the stratum at the construction site. It is intended to provide a head reinforcement structure for piles and PHC piles using them.

In order to achieve the above object, the present invention forms at least one shear groove on the inner circumferential surface of the head cut according to changes in the stratum at the construction site, so that when constructing an expanded foundation on the head, the groove is poured at a predetermined depth in the hollow part of the head. We present a PHC pile with a shear groove that ensures the bond strength between the pile head and the filled concrete by curing a portion of the filled concrete in the shear groove.

Here, a plurality of shear grooves may be formed in multiple stages on the inner peripheral surface of the pile head.

For example, the shear groove may be formed in a ring shape on the inner peripheral surface of the pile head.

For another example, the shear groove may be formed in a spiral shape on the inner peripheral surface of the pile head.

Meanwhile, the shear groove is preferably formed by cutting the PHC pile head according to changes in the stratum at the construction site and then processing the inner peripheral surface of the cut pile head at the construction site.

In addition, in order to achieve the above object, the present invention includes a PHC pile provided with at least one shear groove on the inner peripheral surface of the pile head, a lower transverse main reinforcing bar of the expanded foundation placed on the upper part of the PHC pile head, and a lower transverse bottom of the expanded foundation. The longitudinal main reinforcing bars on the lower side of the expanded foundation, which are connected to the directional main reinforcing bars, the transverse main reinforcing bars on the lower side of the expanded foundation, and the longitudinal main reinforcing bars on the lower side of the expanded foundation are embedded inside, and at the same time, the PHC pile head protruding to the outside of the stratum is embedded inside for a predetermined length. Enlarged foundation concrete is poured on the upper part of the PHC pile as much as possible, and is poured to a predetermined depth inside the PHC pile head so that at least one shear groove formed on the inner peripheral surface of the PHC pile head is partially filled. Infill concrete that unites the head of the PHC pile and the expanded foundation concrete without loss of adhesion between them, and part of the expanded foundation is embedded in the concrete, and the remaining part is embedded in the filled concrete and connected to each other by a plurality of band reinforcing bars. We present a head reinforcement structure for a PHC pile containing a plurality of connected filler rebars.

In addition, the head reinforcement structure of the PHC pile according to the present invention is covered with the cut surface of the PHC pile head embedded for a predetermined length inside the expanded foundation concrete, and the cut surface of the PHC pile head is generated as the pre-stress is released as the head of the PHC pile is cut. It may further include a cut surface reinforcement material to prevent cracking.

In addition, the head reinforcement structure of the PHC pile according to the present invention is arranged at predetermined intervals on the outside of the head of the PHC pile embedded in the expanded foundation concrete so as to be adjacent to the lower surface of the expanded foundation concrete, and are connected to each other by band reinforcing bars. At the same time, reinforcing bars for the lower surface of the expanded foundation may be further included to prevent the lower surface of the expanded foundation concrete from breaking by being embedded inside the expanded foundation concrete.

On the other hand, the bending rigidity of the PHC pile head can be increased by embedding the head inside the expanded foundation concrete by increasing the penetration depth so that the head cut surface can be in close contact with the transverse main reinforcing bar on the lower side of the expanded foundation.

As described above, in the PHC pile with shear grooves according to the present invention and the head reinforcement structure of the PHC pile using the same, a part of the fill concrete filled in the hollow part of the head of the PHC pile is used to integrate the expanded foundation and the PHC pile. It is cured while being filled in the shear groove formed on the inner peripheral surface of the head, and a part of the fill concrete filled in the shear groove functions as a non-slip ridge, so even over time, the adhesion between the fill concrete and the PHC pile is a characteristic of the concrete material in which drying shrinkage occurs. The fixed point can be continuously maintained without being lost due to environmental conditions.

Therefore, the PHC pile head load acting on the filled concrete part is transmitted evenly to the entire PHC pile, so excessive stress is not generated around the PHC pile head, and stress concentration is not generated in the PHC pile and expanded foundation concrete, so the area around the PHC pile head is It has the effect of securing structural stability.

In addition, the head of the PHC pile can be cut in response to changes in the stratum at the construction site and then connected to the expanded foundation, which has the effect of shortening the construction period and ensuring work stability.

In addition, the penetration depth of the PHC pile head embedded in the expanded foundation concrete is increased, and reinforcing bars are placed on the lower surface of the expanded foundation on the outside of the PHC pile head embedded in the expanded foundation concrete so that it is adjacent to the lower surface of the expanded foundation concrete. , By covering the cut surface of the PHC pile head cut in response to changes in the stratum at the construction site and reinforcing it, damage to the expanded foundation concrete can be prevented and the bending rigidity of the PHC pile head can be significantly increased. It has the effect of further improving structural safety by preventing cracking of the cut surface of the PHC pile head that occurs as the pre-stress is released.

Ultimately, the PHC pile with shear grooves according to the present invention and the head reinforcement structure of the PHC pile using the same can shorten the construction period and significantly improve structural safety while ensuring the work safety of field workers. Buildings and bridges constructed using PHC piles do not cause stress concentration in the expanded foundation concrete and ensure that the PHC pile head load acting on the fill concrete is evenly transmitted to the entire PHC pile and transmitted to the high-quality bearing layer at the tip of the PHC pile. It has the effect of significantly improving the structural safety of structures such as the like.

Other effects of the present invention will be readily apparent and understood by experts or researchers in the technical field through the specific details described below or during the process of implementing the present invention.

Figure 1 is a drawing to explain the conventional specification PHC pile and its construction process.
Figure 2 is a diagram illustrating the process of constructing an expanded foundation after cutting the head of a general PHC pile with a single cut.
Figure 3 is a view for explaining a PHC pile according to an embodiment of the present invention
Figure 4 is a view for explaining a PHC pile according to another embodiment of the present invention
Figure 5 is a cross-sectional view illustrating the head reinforcement structure of the PHC pile according to the present invention.
Figure 6 is a plan view illustrating the head reinforcement structure of the PHC pile according to the present invention.

Since the present invention can be subject to various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component without departing from the scope of the present invention.

The terms used in this application are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains.

Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted as having an ideal or excessively formal meaning. No.

Below, with reference to the drawings, preferred embodiments of the present invention will be described in more detail.

Figure 3 is a diagram for explaining a PHC pile according to an embodiment of the present invention, Figure 4 is a diagram for explaining a PHC pile according to another embodiment of the present invention, and Figure 5 is a diagram for explaining a PHC pile according to an embodiment of the present invention. It is a cross-sectional view for explaining the head reinforcement structure, and Figure 6 is a plan view for explaining the head reinforcement structure of the PHC pile according to the present invention.

Referring to Figures 3 to 6, the PHC pile 100 according to the present invention may have at least one shear groove 110 formed on the inner peripheral surface of the cut head according to changes in the stratum at the construction site. On the other hand, for the convenience of explanation, the PHC pile 100 shown in FIGS. 3 to 6 is shown by omitting the longitudinal steel wire or steel bar and the transverse band or spiral reinforcement that are embedded inside during pile production. did.

When constructing the expanded foundation 200 on the head of the PHC pile, the shear groove 110 is cured with a portion of the fill concrete 160 poured at a predetermined depth into the hollow portion 120 of the head of the PHC pile 100. By doing so, the attachment strength of the head of the PHC pile (100) and the filling concrete (160) is secured so that the head of the PHC pile (100) and the expanded foundation (200) can be integrated.

To explain in more detail, generally, when constructing the expanded foundation (200) on the head of the PHC pile (100), the head of the PHC pile (100) is cut in a circle to ensure work safety and shorten the construction period, and then cut. An expanded foundation (200) is constructed on the head of the PHC pile (100). At this time, in order to integrate the head of the PHC pile (100) and the expanded foundation (200), the hollow portion (120) of the head of the PHC pile (100) is filled with concrete (160) to a predetermined depth. ) is cured in a filled state.

As described above, the filled concrete 160 poured into the head hollow portion 120 of the PHC pile 100 initially remains attached to the inner peripheral surface of the PHC pile 100, but over time, the volume decreases due to the characteristics of the concrete material. Adhesion is lost due to drying shrinkage phenomenon, vibration of seismic load, lubrication of groundwater level, cement paste layer called slippery and weak road layer on the inner peripheral surface of PHC pile (100), etc.

In this way, the PHC pile (100) made of concrete material cannot weld the steel shear key to the inner circumferential surface like a steel pipe pile, so the adhesion between the filled concrete (160) and the inner circumferential surface of the PHC pile (100) depends on the characteristics of the material and environmental conditions. Because it is destroyed, it is impossible to create a fixing point, so the head of the PHC pile 100 and the expanded foundation 200 are not integrated and the connection is severed, thereby reducing structural safety.

Accordingly, the PHC pile 100 according to the present invention forms at least one shear groove 110 on the inner peripheral surface of the head of the PHC pile 100, so that a portion of the filling concrete 160 poured on the inner peripheral surface of the head of the PHC pile 100 is formed in the shear groove 110. ) and cured to function as a non-slip ledge so that the PHC pile (100) and the filled concrete (160) are integrated, so that even over time, the adhesion between the filled concrete (160) and the inner peripheral surface of the head of the PHC pile (100) is maintained. By preventing this from being lost, structural safety can be greatly improved.

For example, the shear groove 110 formed on the inner peripheral surface of the head of the PHC pile 100 may be formed in multiple stages on the inner peripheral surface of the head of the PHC pile 100.

Here, the shear groove 110 may be formed in a ring shape on the inner peripheral surface of the head of the PHC pile 100.

Meanwhile, the shear groove 110 may be formed in a spiral shape on the inner peripheral surface of the head of the PHC pile 100.

This shear groove 110 is formed by cutting the head of the PHC pile 100 according to changes in the stratum at the construction site, and then processing the inner peripheral surface of the cut head at the construction site using equipment such as an electric cutter or grinder. It can be.

As described above, the PHC pile 100 equipped with a shear groove according to the present invention is cut by circular cutting the head of the PHC pile 100 embedded in the ground layer according to changes in the ground layer at the construction site for worker safety and shortening the construction period. Even if the expanded foundation 200 is constructed on the top of the PHC pile 100, the filler concrete 160, which is poured to a predetermined depth in the hollow part 120 of the head of the PHC pile 100, is cured while being filled in the shear groove 110. It functions as a non-slip barrier, so even over time, the adhesion between the PHC pile (100) and the filled concrete (160) is not lost due to the characteristics of concrete that dries and shrinks and environmental conditions, and the fixation point is continuously maintained, so that the PHC pile (100) Since the and expanded foundation 200 can be integrated, structural safety can be greatly improved.

Next, the head reinforcement structure of the PHC pile according to the present invention will be described with reference to FIGS. 3 to 6.

Referring to Figures 3 to 6, the head reinforcement structure of the PHC pile according to the present invention includes a shear groove 110, a transverse main reinforcing bar 130 on the lower side of the expanded foundation, a longitudinal main reinforcing bar 140 on the lower side of the expanded foundation, and concrete ( 150), filled concrete (160), and filled rebar (170) may be included. An abandoned concrete layer is formed between the ground and the expanded foundation concrete (150).

At least one shear groove 110 may be formed on the inner peripheral surface of the head of the PHC pile 100, which is embedded in the stratum so that the head protrudes out of the stratum by a predetermined length and is cut in response to changes in the stratum at the construction site.

Here, the PHC pile (100) increases the insertion depth so that the head cut surface can be in close contact with the lower transverse main reinforcing bar (140) of the expanded foundation, and inserts the head inside the expanded foundation concrete (150) to attach the head of the PHC pile (100). Allows to increase bending rigidity.

To explain in more detail, the head reinforcement structure of the general PHC pile (100) is generally such that the head of the PHC pile (100) is injected from the lower surface (210) of the expanded foundation concrete (150) by about 50 mm for buildings and about 100 mm for bridges. While the bending rigidity of the head of the PHC pile (100) is somewhat weakened during construction, the head reinforcement structure of the PHC pile according to the present invention has a cut surface of the head of the PHC pile (100) on the transverse main reinforcing bar (130) on the lower side of the expanded foundation (200). To ensure close contact, the embedding depth (h) is increased to 150 mm and the head is embedded inside the expanded foundation concrete (150), thereby significantly increasing the bending rigidity of the head of the PHC pile (100).

For example, the shear groove 110 formed on the inner peripheral surface of the head of the PHC pile 100 may be formed in multiple stages on the inner peripheral surface of the head of the PHC pile 100.

Here, the shear groove 110 may be formed in a ring shape on the inner peripheral surface of the head of the PHC pile 100.

Meanwhile, the shear groove 110 may be formed in a spiral shape on the inner peripheral surface of the head of the PHC pile 100.

For example, the shear groove 110 is formed by cutting the head of the PHC pile 100 according to changes in the stratum at the construction site, and then cutting the inner peripheral surface of the head cut at the construction site using equipment such as an electric cutter or grinder. It can be formed by processing.

The transverse main reinforcing bar 130 on the lower side of the expanded foundation may be placed on the upper part of the head of the PHC pile 100.

The longitudinal main reinforcing bar 140 on the lower side of the expanded foundation may be bound to the transverse main reinforcing bar 130 on the lower side of the expanded foundation.

The expanded foundation concrete 150 has the transverse main reinforcing bar 130 on the lower side of the expanded foundation and the longitudinal main reinforcing bar 140 on the lower side of the expanded foundation embedded in the inside, and the head of the PHC pile 100 protruding to the outside of the ground layer has a predetermined depth. It can be cast on the top of the PHC pile 100 so that it is embedded inside.

The filled concrete 160 is placed at a predetermined depth inside the head of the PHC pile 100 when the expanded foundation concrete 150 is placed so that at least one shear groove 110 formed on the inner peripheral surface of the head of the PHC pile 100 is partially filled. It is poured as much as possible so that the head of the PHC pile (100) and the expanded foundation concrete (150) can be integrated and combined without loss of adhesion between the inner peripheral surface of the PHC pile (100).

That is, the filled concrete 160, which is cured in a state where the at least one shear groove 110 is partially filled, functions as a non-slip barrier, thereby allowing the PHC pile 100 and the filled concrete 160 to be integrated, thereby saving time. Even if it passes, structural safety can be significantly improved by preventing the adhesion between the filled concrete (160) and the inner peripheral surface of the head of the PHC pile (100) from being lost.

Here, in order to pour the filled concrete 160, the filled concrete support plate is first connected so that a plurality of filled concrete support plate connecting members 161 are inserted into the hollow head portion 120 of the PHC pile 100 to a predetermined depth. After fixing the upper end of the member 161 to the cut surface of the head of the PHC pile 100, the tip of the filled concrete support plate connection member 161 inserted into the hollow head 120 of the PHC pile 100 is filled with concrete. Connect the support plate (162).

Thereafter, the filled concrete 160 can be poured into the hollow head portion 120 of the PHC pile 100 so that the filled concrete 160 is supported by the filled concrete support plate 162.

For example, the upper end of the filled concrete support plate connecting member 161 may be interposed and fixed between the cut surface reinforcement 180 covered by the head cut surface of the PHC pile 100 and the head cut surface of the PHC pile 100. , The filled concrete support plate 162 may be connected to the distal end of the filled concrete support plate connecting member 161 by a connecting member 163 such as a plurality of rings.

A plurality of the filled reinforcing bars 170 may be placed so that a portion is embedded within the expanded foundation concrete 150 and the remaining portion is embedded within the filled concrete 160, and the plurality of filled reinforcing bars 170 are embedded within the expanded foundation concrete 150. The reinforcing bar 170 may be bound to a plurality of band reinforcing bars 171 and connected to each other.

In addition, the head reinforcement structure of the PHC pile according to the present invention may further include a cut surface reinforcement member 180.

The cut surface reinforcement material 180 may be covered with the cut surface of the head of the PHC pile 100 embedded within the expanded foundation concrete 150 for a predetermined length.

Such a cut surface reinforcement material 180 prevents cracking of the cut surface of the head of the PHC pile 100, which occurs when prestress is released as the head of the PHC pile 100 is cut.

The cut surface reinforcement 180 is manufactured to have a 'ㄷ'-shaped cross section so as to surround the inside and outside of the cut surface of the head of the PHC pile 100, but may also be formed integrally in a ring shape, as shown in Figure 6. It is also possible to use one formed by dividing it into multiple pieces.

In addition, the head reinforcement structure of the PHC pile according to the present invention may further include reinforcing bars 190 on the lower surface of the expanded foundation.

The reinforcing bars 190 on the lower surface of the expanded foundation are arranged at predetermined intervals on the outside of the head of the PHC pile 100 embedded in the expanded foundation concrete 150 so as to be adjacent to the lower surface 210 of the expanded foundation concrete 150. It is arranged and bound and connected to each other by the band reinforcing bars 191, and is embedded within the expanded foundation concrete 150 to prevent the lower surface 210 of the expanded foundation concrete 150 from breaking.

The reinforcing bar 190 on the lower side of the expanded foundation is an L-shaped reinforcing bar as shown in FIG. 5, and has a vertical length that is adjacent to the main reinforcing bar on the lower side of the expanded foundation from the bottom of the expanded foundation and a horizontal length that is close to the outer surface of the pile head. It is preferable that one side is adjacent to the main reinforcing bar on the lower side of the expanded foundation and the other side is installed in close contact with the outer surface of the pile head.

Again, with reference to FIGS. 3 to 6, the effect of the PHC pile having a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same will be described.

Referring to Figures 3 to 6, the PHC pile with a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are cut by one-cutting the head of the PHC pile (100) in response to changes in the stratum at the construction site. Afterwards, an expanded foundation 200 is constructed on top of it, thereby ensuring work stability and shortening the construction period.

In addition, by forming at least one shear groove 110 on the inner peripheral surface of the head of the PHC pile 100 that is cut by circular cutting, a portion of the filling concrete 160 poured into the hollow portion 120 of the head of the PHC pile 100 is formed as described above. By curing the filled concrete (160) in the shear groove (110), a portion of the filled concrete (160) filled in the shear groove (110) functions as a non-slip ridge, thereby ensuring secure attachment of the filled concrete (160) to the inner peripheral surface of the PHC pile (100). By securing strength, the PHC piles and expanded foundation can be integrated to improve structural stability.

In other words, the PHC pile with a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are made by crushing the concrete at the head of the PHC pile (100) with a crusher without exposing the reinforcing bars and PC steel bars in the pile body to the outside. Simply cut the head of the PHC pile (100) in response to changes in the stratum at the construction site, and then construct an expanded foundation (200) to reinforce the head, while filling concrete poured into the hollow portion (120) of the head of the PHC pile (100) ( A portion of 160) is filled in the shear groove 110 to function as a non-slip ledge, so that the PHC pile 100 and the filled concrete 160 can be integrated, thereby shortening the construction period, ensuring work stability, and at the same time ensuring structural stability. It also ensures safety.

In addition, the PHC pile with a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are designed so that the head cut surface of the PHC pile (100) can be in close contact with the transverse main reinforcing bar (130) on the lower side of the expanded foundation. ) By increasing the penetration depth (h) of the head and embedding it inside the expanded foundation concrete (150), not only can the bending rigidity of the head of the PHC pile (100) be significantly increased, but also the shallow penetration depth of the head of the PHC pile (100) In addition to preventing damage to the expanded foundation concrete (150), the bending rigidity of the head of the PHC pile (100) can be significantly increased.

In addition, in the case of the head of the PHC pile (100), which is embedded for a predetermined length inside the expanded foundation concrete (150), when cut in response to changes in the stratum at the construction site, the PHC pile (100) applied at the factory when manufacturing the PHC pile (100) There is a problem in that the pre-stress of the head is released and the cut surface of the head of the PHC pile 100 is broken.

Accordingly, the PHC pile with a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are formed by covering the cut surface of the head of the PHC pile (100) with a cut surface reinforcement material (180) in response to changes in the stratum at the construction site. It is also possible to prevent cracking of the cut surface of the head of the PHC pile (100) that occurs as the pre-stress of the head of the PHC pile (100) is released.

In addition, the PHC pile with a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are PHC piles embedded inside the expanded foundation concrete 150 so as to be adjacent to the lower surface 210 of the expanded foundation concrete 150 ( 100) A plurality of reinforcing bars 190 on the lower surface of the expanded foundation, which are connected to each other by band reinforcing bars 191 on the outside of the head, are placed at predetermined intervals and embedded into the expanded foundation concrete 150, thereby forming the lower part of the expanded foundation concrete 150. It even prevents the surface from breaking.

As described above, the PHC pile having a shear groove according to the present invention and the head reinforcement structure of the PHC pile using the same are designed to integrate the expanded foundation 200 and the PHC pile 100, so that the head hollow portion 120 of the PHC pile 100 is integrated. ) is cured in a state in which a part of the filling concrete (160) filled in the shear groove (110) formed on the inner peripheral surface of the head of the PHC pile (100) is filled, and a part of the filling concrete (160) filled in the shear groove (110) is cured. It functions as a non-slip ridge so that even over time, the adhesion between the filled concrete (160) and the PHC pile (100) is not lost due to the characteristics of the concrete material and environmental conditions where drying shrinkage occurs and the anchoring point can be maintained continuously. .

Therefore, the head load of the PHC pile (100) acting on the filled concrete (160) portion is evenly transmitted to the entire PHC pile (100), so excessive stress is not generated around the head of the PHC pile (100), thereby reducing the head load of the PHC pile (100). Since stress concentration does not occur in the expanded foundation concrete (150), structural stability around the head of the PHC pile (100) can be secured.

In addition, since the expanded foundation 200 can be constructed after cutting the head of the PHC pile 100 in response to changes in the stratum at the construction site, the construction period can be shortened and work stability can be ensured.

In addition, the penetration depth (h) of the head of the PHC pile 100 inserted into the expanded foundation concrete 150 is increased, and the inside of the expanded foundation concrete 150 is adjacent to the lower surface 210 of the expanded foundation concrete 150. Not only is the reinforcing bar (190) on the lower surface of the expanded foundation installed on the outside of the head of the buried PHC pile (100), but the cut surface reinforcement (180) is covered on the cut surface of the head of the PHC pile (100) that has been cut in response to changes in the stratum at the construction site. By covering and reinforcing, damage to the expanded foundation concrete (150) can be prevented and the bending rigidity of the head of the PHC pile (100) can be significantly increased, and the PHC pile (100) generated as the pre-stress of the head of the PHC pile (100) is released. 100) Even cracking of the head cutting surface can be prevented, thereby further improving structural safety.

Although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, those skilled in the art or those skilled in the art will understand the spirit of the present invention as described in the patent claims to be described later. It will be understood that the present invention can be modified and changed in various ways without departing from the technical scope.

(110): Shear groove (120): Hollow part
(130): Transverse main reinforcing bar on the lower side of the expanded foundation
(140): Lower longitudinal main reinforcing bar of expanded foundation
(150): Expanded foundation concrete (160): Filled concrete
(170): Filling rebar (180): Cut surface reinforcement
(190): Reinforcing bar at the bottom of the expanded foundation

Claims (8)

delete delete delete delete A PHC pile provided with at least one shear groove on the inner peripheral surface of the pile head;
Transverse main reinforcing bars on the lower side of the expanded foundation placed on the upper part of the PHC pile head;
Lower longitudinal main reinforcing bars of the expanded foundation bound to the lower transverse main reinforcing bars of the expanded foundation;
The expanded foundation concrete is poured on the upper part of the PHC pile so that the lower transverse main reinforcing bars of the expanded foundation and the lower longitudinal main reinforcing bars of the expanded foundation are embedded inside, and at the same time, the PHC pile head protruding to the outside of the ground layer is embedded within a predetermined length;
When pouring concrete for the expanded foundation, the concrete is poured to a predetermined depth inside the PHC pile head so that at least one shear groove formed on the inner peripheral surface of the PHC pile head is partially filled, so that the concrete is poured to a predetermined depth between the head of the PHC pile and the expanded foundation without loss of adhesion between the inner peripheral surface of the PHC pile. Filling concrete that combines concrete into one piece; and
A portion is embedded within the expanded foundation concrete, and the remaining portion is embedded within the filled concrete, and includes a plurality of filled reinforcing bars connected to each other by a plurality of band reinforcing bars,
The PHC pile increases the bending rigidity of the PHC pile head by inserting the pile head inside the concrete of the expanded foundation by increasing the penetration depth so that the cut surface of the pile head can be brought into close contact with the transverse main reinforcing bar on the lower side of the expanded foundation,
A plurality of PHC piles are placed at predetermined intervals on the outside of the head of the PHC pile embedded in the expanded foundation concrete so as to be adjacent to the lower surface of the expanded foundation concrete, and are connected to each other by band reinforcement and are simultaneously embedded within the expanded foundation concrete, thereby forming the lower surface of the expanded foundation concrete. A head reinforcement structure for PHC piles that further includes reinforcing bars at the bottom of the expanded foundation to prevent cracking. According to clause 5,
The PHC further includes a cut surface reinforcement material that covers the cut surface of the PHC pile head embedded for a predetermined length inside the expanded foundation concrete and prevents the cracking phenomenon of the PHC pile head cut surface caused by releasing prestress as the head of the PHC pile is cut. Head reinforcement structure of pile. According to clause 5,
The shear groove is a head reinforcement structure of a PHC pile having a shear groove, characterized in that a plurality of shear grooves are formed in multiple stages on the inner peripheral surface of the pile head. According to clause 5,
The shear groove is a head reinforcement structure of a PHC pile having a shear groove, characterized in that the shear groove is formed in a ring shape or spiral shape on the inner peripheral surface of the pile head.