KR102631860B1 - Reinforcing Structure For Steel Pipe Pile Head Connections To Improve Bending Moment and Distribute Uniform Normal Load - Google Patents

Abstract

The steel pipe pile head reinforcement structure for improving bending moment and equal vertical load distribution according to the present invention includes a steel pipe pile installed in the ground by drilling and driving and having an upper cut surface formed by cutting the upper end surface of the head; Regarding the vertical load/horizontal load/bending shear/bending load acting on the expanded foundation, which is the basic concrete of the ground superstructure in which the head of the steel pipe pile is embedded and placed, and the upper cut surface of the steel pipe pile and the expanded foundation concrete of the expanded foundation. The lower main rebar of the expanded foundation disposed for resistance, a plurality of lower layer through holes formed by drilling from the outside to the inner hollow portion along the circumferential circumference of the head of the steel pipe pile embedded in the expanded foundation, and the circumference of the steel pipe pile. On the upper side of the plurality of lower layer through holes formed along the circumference, an upper layer through hole is formed by drilling from the outside to the inner hollow side along the circumferential circumference of the steel pipe pile, and is inserted into the drilled lower layer through hole and fixed by a fixing nut. It is composed of a bending shear reinforcement including a horizontal reinforcement and an L-shaped reinforcement that is inserted into the drilled upper layer through hole and fixed by a fixing nut, so that the bending moment and lateral restraint effect are improved, thereby improving the fixation of the joint between the steel pipe pile and the expanded foundation. is improved, and the main surface resistance is generated on the main surface of the horizontal reinforcement and L-shaped reinforcement embedded in the concrete cover thickness of the bottom of the expanded foundation and the filling concrete in the hollow part of the steel pipe pile, and the filling concrete and enlarged filling in the hollow part of the steel pipe pile are improved. The outer expanded foundation concrete of the foundation is integrated, which has the effect of preventing the collapse of upper structures (buildings, bridges) placed on top of the expanded foundation.

Description

{Reinforcing Structure For Steel Pipe Pile Head Connections To Improve Bending Moment and Distribute Uniform Normal Load}

In the present invention, the main body of the steel pipe pile is buried longer up to the main rebar at the bottom of the expanded foundation, and in order to reinforce the concrete cover thickness (plain concrete) on the bottom of the expanded foundation, the horizontal reinforcement and L are penetrated through the through hole drilled in the upper part of the head of the steel pipe pile. This relates to a steel pipe pile head reinforcement structure in which a steel pipe pile and an enlarged foundation are connected to each other by inserting and fastening bending shear reinforcement including a shaped reinforcement material. More specifically, the head section of the steel pipe pile is raised and enlarged to contact the lower main rebar of the enlarged foundation. By embedding it longer into the cover thickness of the bottom of the foundation, the head joint of the steel pipe pile is created between the head cut surface of the steel pipe pile, which is the flexural shear vulnerable area that is the first to fail when bending shear such as horizontal load, lateral flow, and earthquake load is applied, and the lower main rebar of the expanded foundation. By reinforcing, the bending moment and lateral restraint effect (hoop tension effect) are improved, improving the degree of rigidity of the joint between the steel pipe pile and the expanded foundation, as well as increasing the degree of rigidity through the through hole drilled in the upper part of the head of the steel pipe pile. An extension surrounding the outer circumferential surface of a steel pipe pile, provided with a bending shear reinforcement formed of horizontal reinforcement that protrudes into and out of the steel pipe pile and an L-shaped reinforcement consisting of a horizontal part and a vertical part in the upper direction that protrude into the inside and outside of the steel pipe pile. By reinforcing the cover thickness (plain concrete) of the bottom of the expanded foundation between the foundation concrete and the steel pipe pile to ensure a stronger bond, the hoop tension effect and the non-slip bump (shear key) effect surrounding the outer peripheral surface of the steel pipe pile are maximized, and in addition, the above By providing large-diameter anchor nuts at the ends of the horizontal reinforcement and the horizontal ends of the L-shaped reinforcement, which penetrate the steel pipe pile and are disposed in the inner hollow portion of the steel pipe pile, the steel pipe pile body and the inside of the steel pipe pile hollow portion are filled. The blocking effect (the sum of the skid bump effect and the composite effect) is maximized between the concrete blocks, and the reinforcement of the lower cast iron bars of the expanded foundation is completely integrated, allowing the vertical load of the superstructure to be evenly distributed to the steel pipe pile head and steel pipe pile body. This relates to a steel pipe pile head reinforcement structure for improving bending moment and uniform vertical load distribution.

When installing a superstructure (building, bridge) on the ground, if the bearing capacity and settlement of the ground are insufficient, steel pipe piles are installed in the ground. The steel pipe piles on the design ground surface are cut and then connected to the expanded foundation. If a connecting member that meets the strong bonding condition is not installed at this connection, large deformation occurs because the stress concentration and strong bonding conditions cannot be satisfied. Therefore, the road bridge design standards (2008) specify that the structural details of the steel connection should be applied to the connection between the steel pipe pile and the expanded foundation. According to this standard, the condition for strong bonding of the head of a steel pipe pile is to install reinforcing steel (anchored steel) in a state where two rows of anti-slip ridges are necessarily installed on the inner surface of the steel pipe pile and have a complete blocking effect with the filling reinforcing bar cast in the hollow part of the pile. ) to connect to the expansion base.

Figure 1a is a drawing to explain the structural details of the steel pipe pile and expanded foundation joint presented in the Road Bridge Design Standard (2008, Korea) and the Road Bridge Specification and Commentary (2017, Japan), and Figure 1b is a view of the steel pipe pile according to the prior art and This is a drawing showing the structure of a multi-purpose head reinforcement device when combining an expanded foundation. Figure 1c is a drawing to explain various coupling methods between a steel pipe pile and an expanded foundation, and Figure 1d is a view showing the connection state between the actual steel pipe pile and the expanded foundation. This is the drawing shown. Figure 1e is a diagram showing the reinforcement status of the lower main rebar of the expanded foundation disposed and installed on the upper part of the head of the steel pipe pile.

As shown in FIGS. 1A and 1B, the method of reinforcing the head of the steel pipe pile 10 to reinforce the insufficient load capacity of the head of the steel pipe pile exposed 10 cm above the abandoned concrete 20-4 of the steel pipe pile 10 is, In connecting the filled rebar network (30) to the head of the steel pipe pile (10) and the expanded foundation (20), the filled rebar network (30) is embedded in the expanded foundation (20) as the "expanded foundation." Referred to as "reinforcement", a non-slip protrusion (12-3) is welded as shown in Figure 1a to tightly bind the steel pipe pile (10) and the filled concrete (10-3) to the inner surface of the head of the steel pipe pile (10), or As shown in Figure 1b, Registered Patent Publication No. 10-0693814 (March 13, 2007), combining with the fill reinforcing bar network (30) using dual connectors (12-1, 12-2) is referred to as "pile head reinforcement". It is said that That is, in this way, the 10 cm upper length of the head of the steel pipe pile (10) is buried in the expanded foundation (20), and the head of the steel pipe pile (10) and the expanded foundation (20) are connected to each other with the reinforcing bar structure (30).

The head of the steel pipe pile (10) is separated by the location of the filled reinforcing bar network (30) installed on the body of the steel pipe pile (10) and the non-slip bump (12-3) welded to the inner surface of the hollow portion of the steel pipe pile (10) body. It is the most important variable that constitutes strong coupling with the expanded basis (20). The non-slip bump 12-3 ensures that the filled concrete 103 filled inside the hollow portion of the steel pipe pile 10 body is integrally bound to the steel pipe pile 10 body.

Referring to the basic concept of the connection between the steel pipe pile and the enlarged foundation in FIG. 1c and the drawing showing the connection state between the actual steel pipe pile and the enlarged foundation as shown in 1d, the steel pipe pile 10 is enlarged as shown on the left side of FIG. 1c. The foundation 20 is embedded (projected) upward from the bottom 20-1 to a height corresponding to the diameter D of the steel pipe pile 10, or as shown on the right side of Figure 1c and Figure 1d, the steel pipe pile (10) is arranged to protrude 10 cm upward from the lower surface (20-1) of the expanded foundation (20), so that a small amount of horizontal displacement occurs at the joint between the steel pipe pile and the expanded foundation, and is designed to have a large degree of irregularity to prevent earthquakes. (Interpretation of Road Bridge Design Standards, 2008).

Figure 1e is a diagram showing the reinforcement state of the lower main rebar of the enlarged foundation disposed and installed on the upper part of the head of the steel pipe pile. As shown, the enlarged section is disposed and installed on the side and upper part of the upper cut surface 11 of the head of the steel pipe pile 10. Looking at the characteristics of the arrangement of the lower main rebar 21 of the foundation, as shown on the left side of Figure 1e, the lower main rebar 21 of the expanded foundation is placed on the side of the steel pipe pile 10, so that the lower main rebar 21 of the expanded foundation is continuous. Since it breaks without being connected, it has the disadvantage of complicating the arrangement of the reinforcement by additionally arranging the inclined reinforcement. This reinforcement method is suitable for fully integrated abutment bridges, retaining walls, soundproof walls, windbreak walls, etc., whose lateral direction is residential, and is a method widely used in North America and Europe.

On the other hand, as shown on the right side of Figure 1e, the lower main reinforcement bars ((21-1, 21-2)) in the transverse and longitudinal directions of the expanded foundation are placed 5 cm above the upper cut surface (11) of the steel pipe pile (10). There is an advantage that the foundation lower main reinforcing bars (21) are continuous and integrated and the reinforcement is simple. This reinforcement method is mainly used in joint bridges and semi-integral abutment bridges where the vertical load is vertical, and is mainly adopted in Southeast Asia such as Korea, Japan, China, and Vietnam.

Meanwhile, many cases of earthquake damage to PHC piles have been reported, but almost no cases have been reported for head reinforcement of steel pipe piles. However, the steel pipe pile head reinforcement as shown on the right side of Figure 1c cannot satisfy complete fixation (strong bonding) with a pile embedment depth of 10 cm as shown on the left, so in the Japanese Road Bridge Specification and East Commentary (2017), the steel pipe pile head reinforcement as shown on the right side of Figure 1c is considered to be tightly coupled.

In addition, the non-slip bump 12-3, which is an important component in the steel pipe pile head reinforcement structure of the prior art, is welded to the inner surface of the steel pipe pile 10, which is a factor in increasing construction costs. In addition, it has been reported that the filled reinforcing bar network 30 was attempted in the form of a perforated plate, but the non-slip bump 12-3 attached through the welding process was excluded and various structures and shapes for head reinforcement of the steel pipe pile were used. Research and development in various ways is also necessary.

Figure 1f is a diagram for explaining the wedge failure (crack) phenomenon at the joint between the steel pipe pile and the expanded foundation according to Figure 1a. As shown in Figures 1a, 1c, and 1d, the steel pipe pile 10 is connected to the expanded foundation. (20) By arranging it so that it protrudes 10 cm upward from the lower surface (20-1), a small amount of horizontal displacement occurs at the joint between the steel pipe pile and the expanded foundation, and by designing it to have a large degree of irregularity, it can firmly withstand earthquake resistance. However, since the cover thickness (20-5) of the bottom of the expanded foundation, which is a section with only expanded foundation concrete between the steel pipe pile (10) and the lower main rebar (21) of the expanded foundation, has only plain concrete, this section has repetitive horizontal/ When the pile head joint is subjected to bending shear due to a vertical seismic load, lateral flow, or wind load, the first section to fail is a wedge failure phenomenon at an angle of 45 to 75 degrees, as shown in the fracture line 25 shown in Figure 1f. It is expected that cracks will occur, and if bending shear failure occurs between the upper cut surface (11) of the steel pipe pile (10) embedded in the expanded foundation (20) and the lower main rebar (21) of the expanded foundation, the pile-expanded foundation joint will have resistance. Since horizontal displacement progresses rapidly without this, reinforcing elements are also urgently required.

Registered Patent Publication No. 10-0693814 (2007. 03. 13)

“Explanation of road bridge design standards (substructure edition)”, Korean Society of Civil Engineers, 2008. “Road Bridge Specification and Explanation”, Japan Road Association, 2017.

In order to solve the problems of the prior art described above, according to the present invention, as a way to prevent bending shear failure by increasing the bending moment between the steel pipe pile embedded in the expanded foundation and the lower main rebar of the expanded foundation, the head cut surface of the steel pipe pile is By embedding and raising the steel pipe piles from the bottom of the expanded foundation by more than 10 cm and less than 15 cm into the cover thickness of the bottom of the expanded foundation to contact the lower main rebar of the expanded foundation, they are destroyed first when bending shear such as horizontal load, lateral flow, and seismic load is applied. By reinforcing the head joint of the steel pipe pile between the cut surface of the head of the steel pipe pile, which is a vulnerable area due to bending shear, and the lower main rebar of the expanded foundation, the bending moment and lateral restraint effect (hoop tension effect) are improved, thereby improving the fixation in the connection between the steel pipe pile and the expanded foundation. By improving the degree of rigidity, it provides a head reinforcement structure for steel pipe piles for improved bending moment and uniform vertical load distribution.

In addition, as a way to reinforce the cover thickness (plain concrete) of the bottom of the expanded foundation between the expanded foundation concrete surrounding the outer peripheral surface of the steel pipe pile and the steel pipe pile, the steel pipe penetrates the through hole formed in the upper part of the head of the steel pipe pile. A composite effect that surrounds the outer circumferential surface of a steel pipe pile by providing a flexural shear reinforcement formed of horizontal reinforcement that protrudes into and out of the pile and an L-shaped reinforcement consisting of a horizontal part and an upper vertical part that protrude into the inside and outside of the steel pipe pile ( The goal is to provide a head reinforcement structure for steel pipe piles to maximize the hoop tension effect and non-slip bump (shear key) effect.

In addition, large diameter anchor nuts are installed at the ends of the horizontal reinforcement installed on the inner side of the steel pipe pile, which is a bending shear reinforcement formed by penetrating through the through hole at the top of the head of the steel pipe pile according to the present invention, and at the horizontal end of the L-shaped reinforcement. By providing this, the blocking effect (sum of the non-slip effect and the composite effect) is maximized between the steel pipe pile body and the concrete filled inside the hollow part of the steel pipe pile, and the lower main reinforcement of the expanded foundation is completely integrated to equalize the vertical load of the upper structure. The goal is to provide a steel pipe pile head reinforcement structure for improving bending moment and uniform vertical load distribution by distributing it to the steel pipe pile head and steel pipe pile body.

The steel pipe pile head reinforcement structure for improving bending moment and equal vertical load distribution according to the present invention includes a steel pipe pile installed in the ground by drilling and driving and having an upper cut surface formed by cutting the upper end surface of the head; About the vertical load, horizontal load, bending shear, and bending load acting on the expanded foundation, which is the basic concrete of the ground superstructure in which the head of the steel pipe pile is embedded and placed, and the upper cut surface of the steel pipe pile and the expanded foundation concrete of the expanded foundation. The lower main rebar of the expanded foundation disposed for resistance, a plurality of lower layer through holes formed by drilling from the outside to the inner hollow side along the circumferential circumference of the head of the steel pipe pile embedded in the expanded foundation, and the steel pipe pile On the upper side of the plurality of lower layer through holes formed along the circumference, an upper layer through hole is formed by drilling from the outside to the inner hollow side along the circumferential circumference of the steel pipe pile, and is inserted into the perforated lower layer through hole and fixed by a fixing nut. It is characterized in that it includes a bending shear reinforcement including a horizontal reinforcement and an L-shaped reinforcement that is inserted into the perforated upper layer through hole and fixed by a fixing nut.

According to the present invention, the horizontal reinforcement is formed with a screw tab and is inserted through the lower layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side and is fixed to the inner and outer peripheral surfaces of the steel pipe pile by a fixing nut. It is attached, and an anchor-type nut of a larger diameter is fastened and attached to one end that is formed to face toward the hollow part inside the steel pipe pile, and the other side that faces the outside of the steel pipe pile is formed to be longer and outward. do.

The L-shaped reinforcement according to the present invention is formed with a screw tab and is inserted through the upper layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side and is fixed to the inner and outer peripheral surfaces of the steel pipe pile by a fixing nut. An anchor-type nut of a larger diameter is fastened and attached to the attached horizontal portion and one end disposed in the hollow portion inside the steel pipe pile, and the other end disposed on the outside of the steel pipe pile is bent to form a band in the vertical direction at the top. It is characterized in that it is formed as a vertical part that is restrained by reinforcing bars and arranged at a height to form a small-structured reinforcing bar network structure.

The L-shaped reinforcement according to the present invention is formed with a screw tab and is inserted through the upper layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side and is fixed to the inner and outer peripheral surfaces of the steel pipe pile by a fixing nut. An anchor-type nut of a larger diameter is fastened to the attached horizontal portion and one end disposed in the hollow portion inside the steel pipe pile, and the other end disposed on the outside of the steel pipe pile is bent to form a plurality of bands in the upper vertical direction. It is characterized in that it is formed as a vertical part that is restrained by reinforcing bars and arranged at a height to form a large reinforcing bar network structure.

According to the present invention, infill reinforcement connects the head of the steel pipe pile and the expanded foundation to resist cracks and bending shear forces occurring between the head of the steel pipe pile embedded in the expanded foundation concrete filled in the expanded foundation and the lower main rebar of the expanded foundation. It is characterized in that it further includes a reinforcing bar network.

According to the present invention, the head length of the steel pipe pile embedded in the expanded foundation from the bottom surface of the expanded foundation, which is the bottom of the expanded foundation, to the upper cut surface of the steel pipe pile head is 10 to 15 cm, or the upper cut surface of the steel pipe pile and the expanded foundation The gap between the lower main rebars of the expanded foundation is 0 to 5 cm high, so that the upper cut surface of the steel pipe pile is embedded and raised longer inside the expanded foundation to the height where it contacts the lower surface of the lower main rebar of the expanded foundation (height that contacts the lower surface). It is characterized by

In order to solve the problems of the prior art described above, according to the present invention, as a way to prevent bending shear failure by increasing the bending moment between the steel pipe pile embedded in the expanded foundation and the lower main rebar of the expanded foundation, the head cut surface of the steel pipe pile is By embedding and raising the steel pipe piles from the bottom of the expanded foundation by more than 10 cm and less than 15 cm into the cover thickness of the bottom of the expanded foundation to contact the lower main rebar of the expanded foundation, they are destroyed first when bending shear such as horizontal load, lateral flow, and seismic load is applied. By reinforcing the head joint of the steel pipe pile between the cut surface of the head of the steel pipe pile, which is a vulnerable area due to bending shear, and the lower main rebar of the expanded foundation, the bending moment and lateral restraint effect (hoop tension effect) are improved, thereby improving the fixation of the joint between the steel pipe pile and the expanded foundation ( There is an effect that the degree of rigidity can be increased.

In addition, as a way to reinforce the cover thickness (plain concrete) of the bottom of the expanded foundation between the expanded foundation concrete surrounding the outer peripheral surface of the steel pipe pile and the steel pipe pile, the steel pipe penetrates the through hole formed in the upper part of the head of the steel pipe pile. A composite effect that surrounds the outer circumferential surface of a steel pipe pile by providing a flexural shear reinforcement formed of horizontal reinforcement that protrudes into and out of the pile and an L-shaped reinforcement consisting of a horizontal part and an upper vertical part that protrude into the inside and outside of the steel pipe pile ( It has the effect of maximizing the hoop tension effect and the non-slip bump (shear key) effect.

In addition, large diameter anchor nuts are installed at the ends of the horizontal reinforcement installed on the inner side of the steel pipe pile, which is a bending shear reinforcement formed by penetrating through the through hole at the top of the head of the steel pipe pile according to the present invention, and at the horizontal end of the L-shaped reinforcement. By providing it, there is an effect of maximizing the blocking effect (the sum of the slippery effect and the composite effect) between the steel pipe pile main body and the concrete filled inside the hollow part of the steel pipe pile.

Figure 1a is a drawing to explain the structural details of the steel pipe pile and expanded foundation joint presented in the Road Bridge Design Standard (2008, Korea) and the Road Bridge Specification and Commentary (2017, Japan).
Figure 1b is a diagram showing the structure of a multi-purpose head reinforcement device when combining a steel pipe pile and an expanded foundation according to the prior art.
Figure 1c is a diagram for explaining various methods of combining steel pipe piles and expanded foundations.
Figure 1d is a diagram showing the connection state between the actual steel pipe pile and the expanded foundation.
Figure 1e is a diagram showing the reinforcement status of the lower main rebar of the expanded foundation disposed and installed on the upper part of the head of the steel pipe pile.
FIG. 1F is a diagram for explaining the wedge failure (crack) phenomenon at the joint between the steel pipe pile and the expanded foundation according to FIG. 1A.
Figure 2a is an overall front view showing the combined structure of a steel pipe pile and an expanded foundation according to the first embodiment of the present invention.
Figure 2b is a perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.
Figure 2c is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.
Figure 2d is an exploded perspective view of the coupling structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.
Figure 2e is a partial enlarged view for explaining the bending shear reinforcement in the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.
Figure 2f is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.
Figure 3a is an overall front view showing the combined structure of a steel pipe pile and an expanded foundation according to the second embodiment of the present invention.
Figure 3b is a perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention.
Figure 3c is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention.
Figure 3d is an exploded perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention.
Figure 3e is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention.
Figure 4a is an overall front view showing the combined structure of a steel pipe pile and an expanded foundation according to the third embodiment of the present invention.
Figure 4b is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention.
Figure 4c is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention.
Figure 4d is an exploded perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention.
Figure 4e is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention.

Since the description of the present invention is only an example for structural or functional explanation, the scope of the present invention should not be construed as limited by the examples described in the text. In other words, since the embodiments can be modified in various ways and can have various forms, the scope of rights of the present invention should be understood to include equivalents that can realize the technical idea.

In all the drawings below, components having the same function are given the same reference numerals, so repeated descriptions are omitted, and the terms described below are defined in consideration of the functions in the present invention, which is consistent with the technical idea of the present invention. It is specified that the concept should be interpreted according to its own common meaning.

Meanwhile, the meaning of the terms described in the present invention should be understood as follows.

Terms such as “first” and “second” are used to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, a first component may be named a second component, and similarly, the second component may also be named a first component.

When a component is referred to as being “connected” to another component, it should be understood that it may be directly connected to the other component, but that other components may exist in between. On the other hand, when a component is referred to as being “directly connected” to another component, it should be understood that there are no other components in between. Meanwhile, other expressions that describe the relationship between components, such as "between" and "immediately between" or "neighboring" and "directly neighboring" should be interpreted similarly.

Singular expressions should be understood to include plural expressions, unless the context clearly indicates otherwise, and terms such as “comprise” or “have” refer to the specified features, numbers, steps, operations, components, parts, or them. It is intended to specify the existence of a combination, and should be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

For each step, identification codes (e.g., a, b, c, etc.) are used for convenience of explanation. The identification codes do not explain the order of each step, and each step clearly follows a specific order in context. Unless specified, events may occur differently from the specified order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

All terms used herein, unless otherwise defined, have the same meaning as commonly understood by a person of ordinary skill in the field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as consistent with the meaning they have in the context of the related technology, and cannot be interpreted as having an ideal or excessively formal meaning unless clearly defined in the present invention.

Additionally, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

<First Example> Steel pipe pile head reinforcement structure with filled reinforcing bar network and bending shear reinforcement

Figure 2a is an overall front view showing the combined structure of the steel pipe pile and the expanded foundation according to the first embodiment of the present invention, and Figure 2b is the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention. It is a perspective view of the steel pipe pile and the expanded foundation according to the first embodiment of the present invention, Figure 2c is a vertical cut perspective view of the combined structure of the steel pipe pile and the expanded foundation lower main rebar according to the first embodiment of the present invention, and Figure 2d is a vertical cut perspective view of the steel pipe pile and the expanded foundation according to the first embodiment of the present invention. This is an exploded perspective view of the joint structure of the lower main rebar.

As shown, the first embodiment of the present invention, a steel pipe pile head reinforcement structure for improving bending moment and uniform vertical load distribution equipped with a filled rebar network and bending shear reinforcement, will be described.

As the first embodiment of the steel pipe pile head reinforcement structure equipped with a filled reinforcing bar network and bending shear reinforcement for improving the bending moment and uniform vertical load distribution of the present invention, as shown in Figures 2a to 2d, the ground In the combined structure of the steel pipe pile 100 installed by drilling and driving and the expanded foundation 200, which is the foundation concrete of the ground superstructure, the pile head of the steel pipe pile 100 including the upper cut surface 110 is existing. It relates to a steel pipe pile head reinforcement structure for improving the bending moment in which the lateral confinement effect of the outer peripheral surface of the head of the steel pipe pile (100) embedded in the expanded foundation concrete (200) is raised higher than the embedding depth of 10 cm.

More specifically, the most vulnerable “flexural shear vulnerable part (plain concrete part)” at the joint between the head of the steel pipe pile 100 and the expanded foundation 200, that is, the repetitive horizontal load such as earthquake load, lateral flow, and wind load. When the head joint of the steel pipe pile 100 is subjected to bending shear due to, etc., the section that is most damaged is the vertical section acting on the upper cut surface 110 of the steel pipe pile 100 and the expanded foundation concrete 203 of the expanded foundation 200. The cover thickness (205) of the bottom of the expanded foundation, which is a section filled only with expanded foundation concrete (203), is installed between the lower main rebars (210) of the expanded foundation that play a role in resisting loads, horizontal loads, bending shear, and bending loads. In order to provide reinforcement, the pile head of the steel pipe pile 100 is pushed into the interior of the expanded foundation 200 so that the upper cut surface 110 of the head of the steel pipe pile 100 is raised to a height where it makes surface contact with the lower main rebar 210 of the expanded foundation. to be purchased for a longer period of time.

That is, the head length of the steel pipe pile 100 embedded in the expanded foundation from the bottom surface 201 of the expanded foundation, which is the bottom of the expanded foundation 200, to the upper cut surface 110 of the head of the steel pipe pile 100 is 10 ~ 15 cm, or the gap between the upper cut surface 110 of the steel pipe pile 100 and the lower main rebar 210 of the expanded foundation 200 is 0 to 5 cm high, and the upper cut surface 110 of the steel pipe pile 100 It is embedded and raised longer into the expanded foundation 200 to a height that contacts the lower surface of the expanded foundation lower main rebar 210 (height that contacts the lower surface).

As shown in FIGS. 2A to 2D, the steel pipe pile 100 is In order to fill the hollow portion inside the head with the filled concrete 103, a disc-shaped filled concrete form 101 is formed at the inner lower part supported by the hook 102. Therefore, the filled concrete 103 poured into the hollow portion inside the head of the steel pipe pile 100 can be cured by restraining it with the filled concrete form 101.

The expanded foundation 200 is the foundation concrete of the ground superstructure, and has an expanded foundation bottom surface 201, which is the lower cross section of the expanded foundation concrete 203, and an expanded foundation upper surface 202, which is the upper cross section of the expanded foundation concrete 203. The head of the steel pipe pile 100 is buried from the bottom surface 201 of the expanded foundation into the concrete 203 of the expanded foundation to a height of 10 cm to 15 cm based on the upper cut surface 110.

The expanded foundation lower main rebar 210 serves to resist vertical load, horizontal load, bending shear, and bending load acting on the expanded foundation concrete 203 in the expanded foundation 200, The upper expanded foundation lower main rebar 212 and the lower expanded foundation lower main rebar 211 are arranged to perpendicularly intersect each other, and the head of the steel pipe pile 100 is located below the lower expanded foundation lower main rebar 211 of the expanded foundation lower main rebar 210. This is the structure in which the main body is arranged. That is, the expanded foundation lower main rebar 210 located at a certain distance from the upper cut surface 110 of the steel pipe pile 100 is the lower layer (transverse) expanded foundation lower main rebar 211 and the upper layer ( It is a structure in which the lower main reinforcing bars 212 of the expanded foundation (in the longitudinal direction) are arranged to cross each other perpendicularly.

Therefore, the steel pipe pile head reinforcement structure for improving the bending moment by the steel pipe pile head raising structure according to the first embodiment of the present invention is the upper cut surface of the head of the steel pipe pile 100 embedded in the expanded foundation concrete 203. In order to resist and support cracks and bending shear forces occurring at the joint between (110) and the expanded foundation lower main rebar 210, the head (steel pipe) of the steel pipe pile 100 exposed to the ground and embedded in the expanded foundation 200 The upper cut surface (110) of the pile is raised to a height of 10 to 15 cm or longer than 10 cm from the bottom surface (201) of the expanded foundation (200), and the upper cut surface (110) of the maximum steel pipe pile (100) is raised to the lower part of the expanded foundation (201). By being further embedded into the expanded foundation concrete 203 of the expanded foundation 200 to a height of surface contact with the main reinforcing bar 210, the steel pipe pile ( Due to the reinforcement structure by head pulling at the joint between the heads including the upper cut surface 110 of 100), the fixation and lateral restraint effect of the steel pipe pile head are maximized to increase the horizontal force and bending shear resistance of the head of the steel pipe pile 100. This is improved and bending moment resistance is increased, which has the effect of preventing bending shear failure in advance.

In addition, as a characteristic part of the steel pipe pile head reinforcement structure equipped with a filled reinforcing bar network and bending shear reinforcement according to the first embodiment of the present invention, the covering thickness 205 of the bottom of the expanded foundation, which is a bending shear vulnerable part, is more strongly reinforced. In order to resist cracks and bending shear forces that occur between the head of the steel pipe pile (100) and the lower main reinforcing bar (210) of the expanded foundation, the bending shear reinforcement (400) is inserted and fastened into the through hole drilled in the upper part of the head of the steel pipe pile (100). is provided.

More specifically, the bending shear reinforcement 400 is made of a straight horizontal reinforcement 410 and an L-shaped reinforcement 420 formed by bending the straight shape, and the L-shaped reinforcement 420 is formed at the bent portion. As a standard, it is divided into a horizontal part (420-1) and a vertical part (420-2). At this time, the end portion of the vertical portion 420-2 is formed to be slightly higher than the height at which the expanded foundation lower main rebar 210 is disposed.

Meanwhile, on the upper part of the steel pipe pile 100 according to the present invention, a plurality of lower layer through holes 105 are formed radially by penetrating from the outside to the inner hollow side along the circumferential edge of the steel pipe pile 100, and the lower layer through holes ( 105), a plurality of upper layer penetration holes 105 are formed radially by penetrating from the outside to the inner hollow portion along the circumferential circumference of the steel pipe pile 100.

That is, the lower layer through hole 105 and the upper layer through hole 105 are formed radially when viewed from the center of the internal hollow portion of the steel pipe pile 100 and are formed in multiple layers in the vertical axis direction of the steel pipe pile 100. It is a structure that works.

Therefore, the horizontal reinforcement 410 among the bending shear reinforcements 400 is inserted into the lower layer through hole 105 and fixed by the fixing nut 411, and the bending shear reinforcement material ( 400), the horizontal portion 420-1 of the L-shaped reinforcement 410 is inserted and fixed by the fixing nut 421.

In addition, the bending shear reinforcement member 400 is a vertical portion 420 of a plurality of L-shaped reinforcement members 410 formed slightly higher than the height at which the expanded foundation lower main rebar 210 is disposed among the bending shear reinforcement members 400 - 2) can be restrained in the transverse direction by the band reinforcing bars 430 to form a circular reinforcing bar network structure.

Figure 2e is a partial enlarged view for explaining the bending shear reinforcement in the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.

As shown, the steel pipe pile (100) is embedded in the space between the bottom surface (201) of the expanded foundation of the present invention and the lower main reinforcing bar (210) of the expanded foundation, that is, embedded into the bottom cover thickness (205) of the expanded foundation. The lower layer through-holes 105 are formed by radially perforating a plurality of pairs, one on the left and right, penetrating from the outside to the inner hollow portion along the circumferential edge of the steel pipe pile 100 at the upper portion, and each of the lower layer penetration holes 105 is formed from the outside of one side of the steel pipe pile 100 to the inside. A horizontal reinforcement member 410 with a screw tab (not marked) is inserted and formed through the hollow side, and is fixed to the part in contact with the steel pipe pile 100 by a fixing nut 421, and is fixed internally to the inner peripheral surface of the steel pipe pile. It is fixed and attached by a nut (411-1), and is fixed and attached to the outer peripheral surface by an outer fixing nut (411-2), and one end of the horizontal stiffener (410) is formed to face toward the hollow portion inside the steel pipe pile (100). An anchor nut 415 of a larger diameter is fastened and attached thereto, and the other side of the horizontal stiffener 410 facing the outside of the steel pipe pile is formed to be disposed outward longer.

In addition, each of the upper layer through holes 105 formed by radially drilling a plurality of holes along the circumferential circumference of the steel pipe pile 100 from the outside toward the inner hollow portion of the lower layer through hole 105 has a steel pipe pile 100. ), the horizontal portion 420-1 of the L-shaped reinforcement 420 formed with a screw tab (unmarked) is inserted and formed by penetrating from one outer side to the inner hollow side, and similarly to the horizontal reinforcement 410, the steel pipe pile is formed. (100) After inserting the horizontal portion (420-1) located on the inner hollow portion and the outer side of the steel pipe pile (100) through the plurality of radial through holes (105) formed in the head, the steel pipe pile (100) is fixed with a nut (421). An L-type fastened and fixed to the inner and outer surfaces of the pile 100 by the inner fixing nut 421-1 and the outer fixing nut 421-2, respectively, and disposed on the inner hollow side of the steel pipe pile 100. At one end of the horizontal portion 420-1 of the reinforcing material 420, an anchor nut 415 having a larger diameter, similar to that of the horizontal reinforcing material 410, is fastened and attached.

The vertical part 420-2, which is bent on the other side of the horizontal part 420-1 of the L-shaped reinforcement 420 and extends vertically, is the expanded foundation lower main rebar 210 provided in the expanded foundation 200 according to the present invention. ) are arranged slightly higher than the surface on which the plurality of vertical parts 420-2 are arranged, and the plurality of vertical parts 420-2 are connected in knots at predetermined intervals in the transverse direction by transverse band reinforcing bars 430 and tie lines (not shown). A cylindrical reinforcing bar network structure is formed.

The height of the vertical portion according to the first embodiment of the present invention is the height of the cross section or vicinity where the other side disposed on the outside of the steel pipe pile is bent and the lower main reinforcing bar of the expanded foundation is arranged in the upper vertical direction, that is, by one band reinforcing bar. It is placed at a height to form a large cylindrical rebar network structure with a relatively low structure at a restrained height.

Therefore, according to the first embodiment of the present invention, a cylindrical concrete structure can be formed inside the expanded foundation by the new type of large cylindrical reinforcing bar network structure with a relatively low height structure.

Preferably, 4 to 12 of the horizontal reinforcement 410 and the L-shaped reinforcement 420 are inserted into the through hole 105 of the head of the steel pipe pile 100 and fixedly arranged.

According to the present invention, in order to resist cracks and bending shear forces occurring between the head of the steel pipe pile (100) embedded in the expanded foundation concrete (203) and the expanded foundation lower main rebar (210), the head and the enlarged steel pipe pile (100) are It is characterized in that it includes a filled reinforcing bar network (300) as a reinforcing medium connecting the foundation (200).

The filled reinforcing bar network 300 includes vertical reinforcing bars 310 in which a plurality of preferably 8 to 12 reinforcing bars are arranged vertically in order to reinforce the head, and an outer side of the vertical reinforcing bars 310. The reinforcing bar 320, which is formed to continuously connect along the circumference, the vertical reinforcing bar 310, and the strip reinforcing bar 320 are knotted and connected at predetermined intervals by tie lines to form a reinforcing bar network structure of a cylindrical column. do.

The lower side of the filled reinforcing bar network 300 is buried inside the hollow portion of the main body of the steel pipe pile 100, and is disposed at an interval of 10 cm from the filled concrete form 101 of the steel pipe pile 100 to the upper part, The upper side of the filled reinforcing bar network 300 is buried inside the expanded foundation 200, but is arranged at a certain length and height above the lower main rebar 210 of the expanded foundation 200, so that the expanded foundation 200 and the expanded foundation 200 are placed at a certain length and height. It is a structure in which the heads of the steel pipe piles 100 are arranged to be connected to each other.

That is, the filled rebar network 300 is disposed on the upper and lower sides based on the lower main rebar 210 of the expanded foundation 200, and the lower side is inside the hollow portion of the steel pipe pile 100. It is a structure that is inserted and placed up to 10 cm above the filled concrete form 101 of the steel pipe pile 100, and the upper side of the filled reinforcing bar network 300 is directed downward toward the upper side of the lower main rebar 210 of the expanded foundation. It is placed at a height corresponding to the length of the placed filling rebar.

At this time, the hook 102 for supporting the filled concrete form 101 is placed over the horizontal reinforcement 410 disposed in the hollow portion of the steel pipe pile 100 of the bending shear reinforcement 400.

Figure 2f is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the first embodiment of the present invention.

As shown, 2f-i is a plan view of a structure including an L-shaped reinforcement coupled to a steel pipe pile on the upper perforated surface based on the perforated cross section where the through hole is formed, and is disposed inside the steel pipe pile 100. The horizontal portion 420-1 of the L-shaped reinforcement 420 is supported and firmly fixed on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 421-1 and 421-2, and the steel pipe pile An anchor-type nut 425 is attached to one end disposed on the inner portion of 100, and a filled reinforcing bar network 300 is disposed between the steel pipe pile 100 and the anchor-type nut 425.

2f-ii is a plan view of a structure including a horizontal reinforcement material coupled to a steel pipe pile on the perforated surface of the lower layer based on the perforated cross section where the through hole is formed. The horizontal reinforcement material 410 disposed inside the steel pipe pile 100 is It is supported and firmly fixed on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 411-1 and 411-2, and an anchor-type nut ( 415) is attached, and a filled reinforcing bar network 300 is disposed between the steel pipe pile 100 and the anchor nut 425. 2f-iii is an overall plan view including the lower main rebar 210 of the expanded foundation.

According to the first embodiment of the present invention, in order to reinforce the cover thickness 205 of the bottom of the expanded foundation, the upper cut surface 110 of the head of the steel pipe pile 100 is brought into surface contact with the lower main rebar 210 of the expanded foundation. It is a structure in which the pile head of the steel pipe pile (100) is embedded longer into the interior of the expanded foundation (200) so as to be raised, and in addition, the head of the steel pipe pile (100) and the expanded foundation (200) have repetitive horizontal/ When a crack occurs in the expanded foundation concrete (203) surrounding the edge of the head of the steel pipe pile (100) embedded in the expanded foundation (200), which is the part that cracks and is destroyed first by the vertical load, the bending shear resistance rapidly increases. It is a reinforcing structure of the head joint of the steel pipe pile (100) to prevent the collapse of the superstructure (building, bridge) located on the upper side of the expanded foundation due to deterioration and ultimately rupture of the filled reinforcing bar network (300). It is a structure equipped with horizontal reinforcement (410) and L-shaped reinforcement (420), which are bending shear reinforcement (400), on the concrete cover thickness (205) of the bottom of the expanded foundation, which is the base of the head joint of the steel pipe pile.

According to the present invention, the horizontal reinforcement (410) of the bending shear reinforcement (400) is embedded in the bottom cover thickness (205) of the expanded foundation, which is the concrete covering of the main surface of the head of the steel pipe pile (100), to prevent the bending acting on the head of the steel pipe pile (100). It has the effect of not only maximizing shear resistance but also inducing strong bonding of the head joint of the steel pipe pile (100).

In addition, a new type of cylindrical shape in which the vertical portion (420-2) of the L-shaped reinforcement (420) of the bending shear reinforcement (400) installed in the vertical direction of the outermost steel pipe pile (100) is bound by the band reinforcement (430) Due to the creation of a cylindrical concrete structure by the reinforcing bar network structure, the bonding effect of the head of the steel pipe pile (100) and the expanded foundation (200) is strongly bonded, thereby improving the bending shear resistance of the head of the steel pipe pile (100). It works.

According to the present invention, the seismic load is generated by the horizontal reinforcement 410 and the horizontal portion 420-1 of the L-shaped reinforcement 420, in which protruding screw tabs are formed on the outer peripheral surface provided on the inner and outer sides of the steel pipe pile 100. Even if the head of the steel pipe pile (100) rotates due to a horizontal load, the horizontal reinforcement (410) embedded in the filling concrete (103) of the hollow part of the steel pipe pile (100) and the concrete cover thickness (205) of the bottom of the expanded foundation And the main surface resistance force is generated on the main surface of the horizontal part (420-1) of the L-shaped reinforcement (420), and the fill concrete (103) and the outer expanded foundation of the expanded foundation (200) are filled in the inner hollow part of the steel pipe pile (100). There is an effect of unifying the concrete 203.

In addition, the horizontal bending shear reinforcement (400) is inserted into the through hole (105) of the steel pipe pile (100) according to the present invention and embedded in the hollow filling concrete (103), and is embedded in the bottom cover thickness (205) of the expanded foundation. Inner/outer fixing nuts (411-1, 411-2) for fastening the reinforcing material (410) and the horizontal reinforcing material (410) to each other to the steel pipe pile (100), and the inside of the hollow portion of the steel pipe pile (100) The hollow part of the steel pipe pile (100) is filled with concrete by the anchor-type bolt (415) embedded in the filling concrete (103) and the screw tab that is derived from the outer peripheral surface of the horizontal reinforcement (410) on the inside/outside of the steel pipe pile (100). (103) and the concrete of the bottom surface cover thickness (205) of the expanded foundation on the outside of the steel pipe pile (00) perform the function of a non-slip ridge so that it is integrated, providing excellent resistance to the vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile (100). In addition, it is inserted into the through hole 105 of the steel pipe pile 100 and embedded in the hollow filling concrete 103, and is embedded in the cover thickness 205 of the bottom of the expanded foundation. 400) of the L-type reinforcement (420), inner/outer fixing nuts (412-1, 412-2), and L-type provided on the inner hollow side of the steel pipe pile (100) to secure it to the inner and outer peripheral surfaces of the steel pipe pile (100). A protruding screw tab is formed on the outer peripheral surface of the anchor nuts 415, 425 and the L-type reinforcement 420 installed at the end of the reinforcement 420 to resist the bending moment acting on the head of the steel pipe pile 100. Anchor function and non-slip bump so that the filling concrete (103) filled in the internal hollow part of the head of the steel pipe pile (100) and the expanded foundation concrete of the expanded foundation (200) existing in the outer periphery of the head of the steel pipe pile (100) are integrated. By performing its role, it can exert excellent resistance to the vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile (100), and can achieve integration of the inside and outside of the steel pipe pile (compounding effect and blocking effect of the inside and outside), so it is a horizontal load. It has the effect of strongly reinforcing the joint of the head of the steel pipe pile (100), which is the most vulnerable due to seismic load, lateral flow, wind load, etc.

< Second Example > Steel pipe pile head reinforcement structure equipped with bending shear reinforcement of a larger structure

Figure 3a is an overall combined front view showing the combined structure of the steel pipe pile and the expanded foundation according to the second embodiment of the present invention, and Figure 3b is the combined structure of the lower main rebar of the steel pipe pile and the expanded foundation according to the second embodiment of the present invention. is a perspective view of, and Figure 3c is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention, and Figure 3d is a steel pipe pile according to the second embodiment of the present invention and This is an exploded perspective view of the joint structure of the lower main rebar of the expanded foundation.

As shown, the second embodiment according to the present invention has the same basic structure as the first embodiment as described below.

The steel pipe pile 100 has a disk-shaped filled concrete form 101 formed at the inner lower part supported by hooks 102 in order to fill the hollow portion inside the head with filled concrete 103. Therefore, the filled concrete 103 poured into the hollow portion inside the head of the steel pipe pile 100 can be cured by restraining it with the filled concrete form 101.

The expanded foundation 200 is the foundation concrete of the ground superstructure, and has an expanded foundation bottom surface 201, which is the lower cross section of the expanded foundation concrete 203, and an expanded foundation upper surface 202, which is the upper cross section of the expanded foundation concrete 203. The head of the steel pipe pile 100 is buried from the bottom surface 201 of the expanded foundation into the concrete 203 of the expanded foundation to a height of 10 cm to 15 cm based on the upper cut surface 110.

The expanded foundation lower main rebar 210 serves to resist vertical load, horizontal load, bending shear, and bending load acting on the expanded foundation concrete 203 in the expanded foundation 200, The upper main rebar 212 of the upper expanded foundation and the lower main rebar 211 of the lower expanded foundation are arranged to perpendicularly intersect each other, and the head of the steel pipe pile 100 is located below the lower expanded foundation lower main rebar 211 of the expanded foundation lower main rebar 210. This is the structure in which the main body is arranged. That is, the expanded foundation lower main rebar 210 located at a certain distance from the upper cut surface 110 of the steel pipe pile 100 is the lower layer (transverse) expanded foundation lower main rebar 211 and the upper layer ( It is a structure in which the lower main reinforcing bars 212 of the expanded foundation (in the longitudinal direction) are arranged to cross each other perpendicularly.

In addition, according to the second embodiment of the present invention, it is a steel pipe pile head reinforcement structure equipped with bending shear reinforcement to form a circular reinforcing bar network structure of a larger shape, and the cover thickness 205 of the bottom of the expanded foundation, which is a bending shear vulnerable part, is A bending shear reinforcement material formed in the through hole formed at the upper end of the head of the steel pipe pile (100) to resist cracks and bending shear forces that occur between the head of the steel pipe pile (100) and the lower main rebar (210) of the expanded foundation by reinforcing it more strongly. (400) is provided.

More specifically, the bending shear reinforcement 400 is made of a straight horizontal reinforcement 410 and an L-shaped reinforcement 420 formed by bending the straight shape, and the L-shaped reinforcement 420 is a horizontal portion 420. It is divided into -1) and vertical part (420-2). At this time, the vertical portion 420-2 passes through the surface on which the lower main reinforcing bar 210 of the expanded foundation is disposed and is formed to be longer in a direction perpendicular to the upper part.

The bending shear reinforcement 400 for forming a large cylindrical rebar network structure according to the present invention has a structure very similar to the second embodiment of the present invention, and has a cover thickness of the bottom of the expanded base of the main surface of the head of the steel pipe pile 100. A horizontal reinforcement (410) that is embedded in (205) and has a straight externally protruding screw tab formed in order to maximize the bending shear resistance force acting on the head of the steel pipe pile (100) and induce strong bonding of the steel pipe pile head joint, It is formed by a horizontal part (420-1) penetrating inside the steel pipe pile (100) and a vertical part (420-2) disposed in a vertical direction to the outermost side of the steel pipe pile (100), and the inner filling of the steel pipe pile (100) is made of concrete. It includes an L-shaped reinforcement (420) formed to integrate with and improve the bending shear resistance of the head of the steel pipe pile (100), and a plurality of vertical portions arranged in a vertical direction to the outermost part of the steel pipe pile (100). It is characterized in that it further includes a band reinforcing bar (430) for binding the (420-2) to form a cylindrical reinforcing bar network structure in the shape of a cylinder.

The height of the vertical portion according to the second embodiment of the present invention is 80 cm to 1 m in the upper vertical direction when the other side disposed on the outside of the steel pipe pile is bent. This is because the band reinforcement is arranged and restrained at intervals of 15 cm, 6 to 1 m. The height restrained by the number of band reinforcing bars of about 7 is arranged at a height to form a large cylindrical reinforcing bar network structure with a relatively high length.

Therefore, according to the second embodiment of the present invention, a cylindrical concrete structure can be formed inside the expanded foundation by the new type of large cylindrical reinforcing bar network structure with a relatively high height.

In other words, it is formed by binding a plurality of vertical parts 420-2 by the band reinforcement 430, and is a cylinder with a larger structure that can resist bending moment over a larger radius based on the center of the steel pipe pile 100. (Reinforcement) Because a new type of cylindrical concrete structure is formed inside the expanded foundation (200) due to the reinforcing bar network structure, the head of the steel pipe pile (100) and the expanded foundation (200) are strongly coupled to each other, resulting in a strong bonding effect. There is an effect of improving the bending shear resistance of the head of the pile 100.

The straight horizontal reinforcement 410 of the bending shear reinforcement 400 according to the present invention, and the L-shaped reinforcement 420 consisting of a horizontal part 420-1 and a vertical part 420-2 are located on the upper part of the head of the steel pipe pile. It is fixed to a through hole 105 formed in two layers, an upper layer and a lower layer, along the circumferential edge by fixing nuts 411 and 421.

That is, the horizontal reinforcement 410 among the bending shear reinforcements 400 is inserted into the lower layer through hole 105, and an outer fixing nut (411-1) of the fixing nuts 411 is installed on the inner circumferential surface. It is fastened and fixedly arranged by 411-2), and the horizontal portion 420-1 of the L-shaped reinforcement 410 of the bending shear reinforcement 400 is inserted into the upper layer through hole 105, and a fixing nut ( 421) It is a structure that is fastened and fixed to the outer peripheral surface by the inner fixing nut 421-1 by the outer fixing nut 421-2, and also the horizontal reinforcement disposed on the inner hollow side of the steel pipe pile 100 ( One end of 410) and one end of the horizontal portion 420-1 of the L-shaped reinforcement 410 are fastened with an anchor-type nut of a larger diameter, thereby ensuring that the horizontal reinforcement 410 and the L-shaped reinforcement 420 are horizontal. One member, fixing nuts 411 and 421 for fixing to the inner and outer peripheral surfaces of the steel pipe pile 100, and an anchor fastened to one end of the horizontal reinforcement 410 disposed on the hollow side of the steel pipe pile 100. The hollow part of the steel pipe pile (100) is formed by the anti-slip effect of the anchor and anchoring function of the anchor-type nut (425) fastened to the end of the horizontal part (420-1) of the type nut (415) and the L-type reinforcement (410). The filling concrete (103), the steel pipe pile (100), and the cover thickness (205) of the bottom of the expanded foundation on the outside of the steel pipe pile are integrated with each other to demonstrate excellent resistance to the vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile (100). Therefore, the head of the steel pipe pile 100 has the effect of being reinforced under a strong bond condition.

Figure 3e is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the second embodiment of the present invention.

As shown, 3e-i is a plan view of a structure including an L-shaped reinforcement coupled to a steel pipe pile on the perforated surface of the upper layer based on the perforated cross section in which the through hole is formed, the steel pipe pile 100 The horizontal portion 420-1 of the L-shaped reinforcement 420 disposed inside is firmly supported on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 421-1 and 421-2. It is fixed, and an anchor-type nut 425 is attached to one end of the steel pipe pile 100, and a cylindrical reinforcing bar network structure with a larger structure is attached to the steel pipe pile 100 by the band reinforcement 430. It is placed on the outermost edge of.

3e-ii is a plan view of a structure including a horizontal reinforcement member coupled to a steel pipe pile on the perforated surface of the lower layer based on the perforated cross section where the through hole is formed. The horizontal reinforcement member 410 disposed inside the steel pipe pile 100 is It is supported and firmly fixed on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 411-1 and 411-2, and an anchor-type nut ( It is formed by attaching 415), and 3e-iii is an overall plan view including the lower main rebar 210 of the expanded foundation.

< Third Embodiment > Steel pipe pile head reinforcement structure with larger structure of flexural shear reinforcement and filler reinforcing bar network.

Figure 4a is an overall combined front view showing the combined structure of the steel pipe pile and the expanded foundation according to the third embodiment of the present invention, and Figure 4b is the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention. Figure 4c is a vertical cut perspective view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention, and Figure 4d is a vertical cut perspective view of the steel pipe pile according to the third embodiment of the present invention and This is an exploded perspective view of the joint structure of the lower main rebar of the expanded foundation.

As shown, the steel pipe pile head reinforcement structure having a larger structure of bending shear reinforcement and a filled reinforcing bar network according to the third embodiment of the present invention is the same as the structure of the second embodiment, and thus the filled reinforcement It is a structure that further includes a reinforcing bar network (300).

Therefore, the filled reinforcing bar network 300 is disposed inside the cylindrical rebar network structure and the steel pipe pile 100 of a larger structure by the band rebar 430 according to the second embodiment.

The filled reinforcing bar network 300 includes vertical reinforcing bars 310 in which a plurality of preferably 8 to 12 reinforcing bars are arranged vertically in order to reinforce the head, and an outer side of the vertical reinforcing bars 310. A cylindrical column structure is formed by knotting the band reinforcing bars 320, which are formed to continuously connect along the circumference, and the vertical reinforcing bars 310 and the band reinforcing bars 320 at predetermined intervals using tie lines.

In order to form a cylindrical reinforcing bar network with a larger structure formed at the outermost part of the filled reinforcing bar network 300, the vertical portions 420-2 of the L-shaped reinforcing material 420 are formed in 4 to 12 pieces. Do it as

Therefore, according to the third embodiment of the present invention, in addition to the filling reinforcing bar network 300 on the hollow side of the steel pipe pile 300, a larger cylindrical reinforcing bar network structure is used on the outside of the steel pipe pile 100. Since a larger reinforced concrete structure is formed in the expanded foundation 200, the resistance to vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile 100 is improved, resulting in a safer and superior structure.

Figure 4e is a plan view of the combined structure of the steel pipe pile and the lower main rebar of the expanded foundation according to the third embodiment of the present invention.

As shown, 4e-i is a plan view of a structure including an L-shaped reinforcement coupled to a steel pipe pile on the perforated surface of the upper layer based on the perforated cross section where the through hole is formed, and is disposed inside the steel pipe pile 100. The horizontal portion 420-1 of the L-shaped reinforcement 420 is supported and firmly fixed on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 421-1 and 421-2, and the steel pipe pile An anchor-type nut 425 is attached to one end disposed on the inner part of (100), and a filled reinforcing bar network 300 is disposed between the steel pipe pile 100 and the anchor-type nut 425, and its maximum To the outside, the vertical portion 420-2 of the L-shaped reinforcement 420 is restrained by the band reinforcing bar 430, and a circular reinforcing bar network structure with a larger structure is formed and placed.

4e-ii is a plan view of a structure including a horizontal reinforcement member coupled to a steel pipe pile on the perforated surface of the lower layer based on the perforated cross section where the through hole is formed. The horizontal reinforcement member 410 disposed inside the steel pipe pile 100 is It is supported and firmly fixed on the inner and outer peripheral surfaces of the steel pipe pile 100 by the inner and outer fixing nuts 411-1 and 411-2, and an anchor-type nut ( 415) is attached, and a filled reinforcing bar network 300 is disposed between the steel pipe pile 100 and the anchor nut 425. 4e-iii is an overall plan view including the lower main rebar 210 of the expanded foundation.

Therefore, according to the steel pipe pile head reinforcement structure provided with a larger structure of flexural shear reinforcement and a filling reinforcing bar network according to the present invention, the head cut surface of the steel pipe pile is raised to contact the lower main rebar of the expanded foundation to increase the cover thickness of the bottom of the expanded foundation. By embedding it longer into the core, the bending moment is increased by reinforcing the head joint of the steel pipe pile between the head cut surface of the steel pipe pile, which is the most vulnerable part to bending shear, which is the first to fail when bending shear such as horizontal load, lateral flow, and earthquake load is applied, and the lower main rebar of the expanded foundation. The hoop tension effect is improved, which increases the degree of rigidity of the joint between the steel pipe pile and the expanded foundation.

In addition, according to the third embodiment of the present invention, the horizontal reinforcement 410 of the bending shear reinforcement 400 is embedded in the bottom cover thickness 205 of the expanded foundation, which is the concrete covering of the main surface of the head of the steel pipe pile 100, to form a steel pipe pile ( 100) It has the effect of not only maximizing the bending shear resistance acting on the head, but also inducing strong bonding of the head joint of the steel pipe pile (100).

According to the third embodiment of the present invention, the vertical portion 420-2 of the L-shaped reinforcement 420 of the flexural shear reinforcement 400 installed in the vertical direction of the outermost steel pipe pile 100 is connected to the band reinforcement 430. The steel pipe pile ( 100) It has the effect of improving the bending and shear resistance of tofu.

According to the third embodiment of the present invention, the horizontal reinforcement 410 and the horizontal portion 420-1 of the L-shaped reinforcement 420 are formed with protruding screw tabs on the outer peripheral surface provided on the inner and outer sides of the steel pipe pile 100. ) Even if the head of the steel pipe pile (100) rotates due to an earthquake load or horizontal load, the steel pipe pile (100) is embedded in the filling concrete (103) of the hollow part and the concrete cover thickness (205) of the bottom of the expanded foundation. The main surface resistance is generated on the main surface of the horizontal part (420-1) of the horizontal reinforcement (410) and the L-type reinforcement (420), and the filling concrete (103) and expanded foundation (200) are filled in the hollow part inside the steel pipe pile (100). ), the outer expanded foundation concrete 203 is integrated, which has the effect of preventing the collapse of the upper building (building, bridge) placed on top of the expanded foundation 200.

According to the third embodiment of the present invention, a bending shear reinforcement ( The horizontal reinforcement 410 of 400, the inner/outer fixing nuts 411-1, 411-2 for fastening the horizontal reinforcement 410 to the steel pipe pile 100, and the steel pipe pile 100 ) The steel pipe pile (100) is hollowed out by the anchor-type bolt (415) embedded in the filling concrete (103) of the hollow part, and the screw tab that is derived from the outer peripheral surface of the horizontal reinforcement (410) to the inside/outside of the steel pipe pile (100). The vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile (100) performs the function of a non-slip bump so that the subfilling concrete (103) and the concrete of the bottom cover thickness (205) of the expanded foundation outside the steel pipe pile (00) are integrated. It has the effect of demonstrating excellent resistance to

In addition, according to the third embodiment of the present invention, it is inserted into the drilled through hole 105 of the steel pipe pile 100, is embedded in the hollow filling concrete 103, and is embedded in the cover thickness 205 of the bottom of the expanded foundation. In order to secure the L-shaped reinforcement (420) of the bending shear reinforcement (400) to the inner and outer peripheral surfaces of the steel pipe pile (100), the inner/outer fixing nuts (412-1, 412-2) and the inner hollow side of the steel pipe pile (100) Anchor nuts 415, 425 installed at the ends of the L-shaped reinforcement 420 and a protruding screw tab are formed on the outer circumferential surface of the L-shaped reinforcement 420, thereby forming a bending moment acting on the head of the steel pipe pile 100. The anchor function to resist and the fill concrete (103) filled in the internal hollow part of the head of the steel pipe pile (100) and the expanded foundation concrete of the expanded foundation (200) present in the outer periphery of the head of the steel pipe pile (100) are integrated. By acting as a non-slip ledge, it can exert excellent resistance to the vertical force, horizontal force, and bending moment acting on the head of the steel pipe pile (100), thereby achieving integration of the inside and outside of the steel pipe pile (compounding effect and blocking effect of the inside and outside). Therefore, there is an effect of strongly reinforcing the joint of the head of the steel pipe pile (100), which is the most vulnerable due to horizontal loads such as seismic load, lateral flow, and wind load.

5, 50: Ground 10, 100: Steel pipe pile
10-1, 101: Filled concrete form 10-2, 102: Hook
10-3, 103: Filled concrete 105: Through hole
11, 110: Upper cut surface of steel pipe pile 12: Shear key
12-1: Combined connector 1 12-2: Combined connector 2
12-3: Non-slip bump
20, 200: Enlarged base 20-1, 201: Bottom surface of expanded base
20-2, 202: Top surface of expanded foundation 20-3, 203: Concrete expanded foundation
20-4. 204: Abandoned concrete
20-5, 205: Covering thickness of bottom of expanded foundation 25: Destruction line
210: Expanded foundation lower main rebar
21-1, 211: Lower main rebar of expanded lower floor foundation
21-2, 212: Lower main rebar of upper expanded foundation
30, 300: Filled reinforcing bar network 31, 310: Vertical reinforcing bar
32, 320: Band rebar 33, 330: Assembly rebar
34: support part
400: Bending shear reinforcement material
410: Horizontal reinforcement 411: Fixing nut
411-1: Inner fixing nut 411-2: Outer fixing nut
415: Anchor type nut
420: L-shaped reinforcement 420-1: Horizontal part
420-2: Vertical part 421: Fixing nut
421-1: Inner fixing nut 421-2: Outer fixing nut
425: Anchor type nut 430: Band rebar

Claims (6)

A steel pipe pile installed in the ground by drilling and driving and having an upper cut surface formed by cutting the upper end surface of the head;
an expanded foundation which is the basic concrete of the above-ground superstructure in which the head of the steel pipe pile is embedded and placed;
Main reinforcing bars at the bottom of the expanded foundation arranged to resist vertical loads, horizontal loads, bending shear, and bending loads acting on the upper cut surface of the steel pipe pile and the expanded foundation concrete of the expanded foundation;
The upper part of the head of the steel pipe pile, including the upper cut surface formed on the upper end surface of the steel pipe pile, is disposed at the cover thickness of the bottom of the expanded foundation between the lower main rebar of the expanded foundation and the lower surface of the expanded foundation,
A plurality of lower layer through holes formed by drilling from the outside to the inner hollow portion along the circumferential circumference of the head of the steel pipe pile embedded in the expanded foundation, and an upper portion of a plurality of lower layer through holes formed along the circumference of the steel pipe pile. On the side, an upper layer through hole is formed by drilling from the outside to the inner hollow side along the circumferential circumference of the steel pipe pile; and
A bending shear reinforcement including a horizontal reinforcement inserted into the drilled lower layer through-hole and fixedly arranged by a fixing nut and an L-shaped reinforcement inserted into the perforated upper layer through-hole and fixedly arranged by a fixing nut; A steel pipe pile head reinforcement structure for improving bending moment and uniform vertical load distribution, comprising: In claim 1,
The horizontal reinforcement is formed with a screw tab and is inserted through a lower layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side and is fixed and attached to the inner peripheral surface and the outer peripheral surface of the steel pipe pile by a fixing nut, An anchor-type nut of a larger diameter is fastened and attached to one end of the steel pipe pile that is formed to face the hollow portion inside, and the other side that faces the outside of the steel pipe pile is formed to be longer and outward. Improved bending moment. Steel pipe pile head reinforcement structure for. In claim 2,
The L-shaped reinforcement is formed with a screw tab and is inserted through the upper layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side, and is a horizontal structure fixed and attached to the inner peripheral surface and the outer peripheral surface of the steel pipe pile by fixing nuts. An anchor-type nut of a larger diameter is fastened and attached to one end disposed in the hollow portion inside the steel pipe pile, and the other end disposed on the outside of the steel pipe pile is bent and secured by one band reinforcing bar in the upper vertical direction. A steel pipe pile head reinforcement structure for improving bending moment, characterized in that it is formed of vertical parts that are restrained and arranged at a height to form a small-structured reinforcing bar network structure. In claim 2,
The L-shaped reinforcement is formed with a screw tab and is inserted through the upper layer through hole drilled in the steel pipe pile from one outer side of the steel pipe pile to the inner hollow side, and is a horizontal structure fixed and attached to the inner peripheral surface and the outer peripheral surface of the steel pipe pile by fixing nuts. An anchor-type nut of a larger diameter is fastened and attached to one end disposed in the hollow portion inside the steel pipe pile, and the other end disposed on the outside of the steel pipe pile is bent and secured by a plurality of band reinforcing bars in the upper vertical direction. A steel pipe pile head reinforcement structure for improving bending moment, characterized in that it is formed of vertical parts that are restrained and arranged at a height to form a large rebar network structure. The method according to any one of claims 1 to 4,
In order to resist cracks and bending shear forces occurring between the head of the steel pipe pile embedded in the expanded foundation concrete filled in the expanded foundation and the lower main rebar of the expanded foundation, a filled reinforcing bar network is added to connect the head of the steel pipe pile and the expanded foundation. A steel pipe pile head reinforcement structure for improving bending moment and uniform vertical load distribution, which includes: In claim 5
Characterized in that the upper cut surface of the steel pipe pile is buried and raised longer into the expanded foundation so as to come into surface contact with the lower main rebar provided in the expanded foundation without a gap between the upper cut surface of the steel pipe pile and the lower main rebar provided in the expanded foundation. Steel pipe pile head reinforcement structure to improve bending moment.