KR102680217B1 - Load transfer system using post-tension for vertical story-addedextension of buildings - Google Patents

Abstract

The present invention relates to a load transfer system for vertical expansion using post-tension, which can appropriately adjust the strength ratio of existing piles by transferring the load by introducing prestress to transition walls such as existing basement walls during vertical expansion in building remodeling work.
The present invention is installed on a transition wall, which is the lower underground part of an existing wall, in order to transfer the upper load from a vertically expanded structure and adjust the capacity ratio of the existing pile that supports the structure, and is installed at two points spaced apart from each other of the transition wall. A first anchor and a second anchor respectively fixedly installed; Tension members, both ends of which are respectively fixed to the first anchor and the second anchor, introduce vertical prestress through post-tension to the transition wall and introduce vertical axial force to reduce the reaction force; and a deflection port provided on the transition wall at a point spaced apart from the connection line between the first anchor and the second anchor, to bend the tension member. Consisting of the first anchor, second anchor and deflection, the tension member is formed in an L-type or U-shape, and the vertical portion of the tension member is disposed on the side of the existing pile where load capacity ratio reduction is required.

Description

Load transfer system using post-tension for vertical story-addedextension of buildings}

The present invention relates to a load transfer system for vertical expansion using post-tension, which can appropriately adjust the strength ratio of existing piles by transferring the load by introducing prestress to transition walls such as existing basement walls during vertical expansion in building remodeling work.

As 30 years have passed since the construction of the first new cities, such as Bundang, Ilsan, Pyeongchon, Jungdong, and Sanbon, where apartments were supplied on a large scale, the number of aging apartments is rapidly increasing, and remodeling is attracting attention as an alternative due to the recent strengthening of private reconstruction regulations. I'm dragging.

Remodeling is the act of making major repairs or extending or remodeling part of a building to prevent deterioration of the building or improve its function (Article 2, Paragraph 1, Item 10 of the Building Act). Accordingly, unlike new construction or reconstruction, it refers to activities that preserve existing buildings without demolishing them, maintaining the physical performance of the building in use while improving social performance.

Among these remodeling projects, there is a lot of interest in extensions that can increase the total floor area of existing buildings. In particular, vertical expansion has better business feasibility than horizontal expansion, which inevitably requires additional building space, and with the recent partial relaxation of regulations related to vertical expansion, related projects are expected to expand.

Vertical expansion increases the vertical load, so additional piles must be constructed to support the added vertical load.

For this purpose, conventionally, the foundation was drilled to form a through hole, and reinforcement piles were inserted into the ground through the through hole for construction. However, since the reinforcing piles are constructed in the indoor space underground of the existing structure, construction is very difficult and construction costs are high.

In addition, while existing piles already support the load of the existing structure, they receive additional load due to expansion, while newly constructed reinforced piles only receive additional load due to expansion without the burden of the load of the existing structure. Therefore, a load imbalance occurs between the existing pile and the newly constructed reinforced pile.

In addition, the existing piles that are already installed and the newly installed reinforced piles have different frictional forces due to the difference in displacement of the surrounding ground, and the amount of elastic deformation of the piles is also different, showing different behavior characteristics.

Therefore, if the pile is designed without considering the unevenness of load and behavior, there is a problem of uneven settlement or additional moment occurring in the foundation, which increases the burden on the foundation.

Registered Patent No. 10-1494260 was developed to solve problems caused by additional construction of existing reinforcement piles. The registered technology resolves the load imbalance with existing piles by installing supports and preload jacks on the top of additionally constructed reinforcing piles and anchoring the piles to the foundation base plate while applying a preload to the newly constructed reinforcing piles (Figure One).

However, this method of applying a preload requires installing a large support to apply the preload, and this work is performed in an underground space, making construction difficult. In addition, the work is cumbersome because the support must be removed again after applying the preload.

In order to solve the above problems, the present invention is a post-tension system that can appropriately adjust the strength ratio of existing piles by transferring the load by introducing pre-stress to transition walls such as basement walls by post-tension during vertical expansion in building remodeling construction. The aim is to provide a load transfer system for vertical expansion using .

The present invention seeks to provide a load transfer system for vertical expansion using post-tension, which is easy to construct because it does not require the loading and removal process of a preceding load and therefore does not require installation of large-scale supports in the underground space.

The present invention according to a preferred embodiment is installed on a transition wall, which is the lower underground part of an existing wall, in order to transfer the upper load from a vertically expanded structure and adjust the capacity ratio of the existing pile supporting the structure, and the transition wall is connected to each other. A first anchor and a second anchor respectively fixedly installed at two spaced apart points; Tension members, both ends of which are respectively fixed to the first anchor and the second anchor, introduce vertical prestress through post-tension to the transition wall and introduce vertical axial force to reduce the reaction force; and a deflection port provided on the transition wall at a point spaced apart from the connection line between the first anchor and the second anchor, to bend the tension member. It consists of a post-tensioner, wherein the first anchor, the second anchor and the deflection port are arranged so that the tension member is formed in an L-type or U-shape so that the vertical portion of the tension member is located on the side of the existing pile where the strength ratio needs to be reduced. Provides a load transfer system for vertical expansion using

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In the present invention according to another preferred embodiment, a first anchor, a second anchor and a deflection are disposed so that the tension member applies prestress in a vertical direction to the outer side of the transition wall, and a transition is provided at one or both ends of the transition wall. A frame is provided, and a load transfer system for vertical expansion using post-tension is provided, wherein the ground below the transition frame is provided with reinforcing piles to support the vertical load transferred to the transition frame.

The present invention according to another preferred embodiment provides a load transfer system for vertical expansion using post-tension, wherein the transition frame includes an inclined strut whose upper end is fixed to the upper side of the transition wall.

According to the present invention, it is possible to provide a load transfer system for vertical expansion using post-tension, which includes a tension member that introduces prestress to a transition wall such as a basement wall of an existing structure.

Accordingly, during vertical expansion during building remodeling work, the load capacity ratio of the existing pile can be appropriately adjusted by introducing prestress through post-tension to the transition wall and transferring the load.

In addition, there is no need for a process of applying or removing a preload, and there is no need to install a large support in the underground space to apply a preload, making construction easy.

In addition, since the length of the tendon can be increased by using a deflection groove, the size of the final tension that can be introduced after the tension of the tendon is lost can be increased.

Figure 1 is a diagram showing existing patent registration No. 10-1494260.
Figure 2 is a perspective view showing a load transfer system for vertical expansion of the present invention.
Figure 3 is an elevation view showing the stress change when prestress is introduced into the tendon.
Figure 4 is a perspective view showing another embodiment of a tendon arranged in an L shape.
Figure 5 is a perspective view showing an embodiment in which L-shaped tendons are arranged symmetrically left and right.
Figure 6 is a perspective view showing an example of a tendon arranged in a U shape.
Figure 7 is a perspective view showing an example of a tendon arranged in an inverted U shape.
Figure 8 is a perspective view showing an embodiment equipped with a transition frame.
Figure 9 is an elevation view showing the load transfer process when a transition frame is provided.

Hereinafter, the present invention will be described in detail according to the accompanying drawings and preferred embodiments.

Figure 2 is a perspective view showing the load transfer system for vertical expansion of the present invention, and Figure 3 is an elevation view showing the stress change when prestress is introduced into the tendon.

As shown in Figures 2 and 3, the load transfer system for vertical expansion using post-tension of the present invention transfers the upper load from the vertically expanded structure to adjust the load capacity ratio of the existing pile 13 supporting the structure. It is installed on the transition wall (11), which is the lower underground part of the existing wall (1), and the first anchor (2) and the second anchor (3) are respectively fixed and installed at two spaced apart points of the transition wall (11). ; Tension material, both ends of which are respectively fixed to the first anchor (2) and the second anchor (3), introduces prestress in the vertical direction through post-tension to the transition wall (11), thereby reducing the action reaction force by introducing axial force in the vertical direction. (4); and a deflection port (5) provided on the transition wall (11) at a point spaced apart from the connection line between the first anchor (2) and the second anchor (3) to bend the tension member (4); It is characterized by being composed of.

The present invention is for vertical expansion using post-tension, which can appropriately adjust the load capacity ratio of the existing pile (13) by transferring the load by introducing pre-stress to the transition wall (11) by post-tension during vertical expansion in building remodeling work. It is intended to provide a load transfer system.

The present invention is intended to control the capacity ratio of the existing pile 13 by transferring the additional load of the vertically expanded structure during remodeling work, but in some cases, it can also be applied to horizontal expansion or reinforcement of the existing structure.

For this purpose, the lower load-bearing wall, which is the lower part of the existing wall (1), is used as the transition wall (11).

In other words, the transition wall 11 is not a transition member of an existing structure, but a part that becomes a transition member by introducing prestress through post-tension to the general load-bearing wall of the existing structure.

If the existing structure is an apartment complex, the transition wall 11 may be an underground wall. An existing base plate (12) is provided at the lower part of the wall (1) of the existing structure.

In particular, when using the underground PIT floor wall as a transition wall (11), additional vertical load can be transferred without hindering the use of underground spaces such as underground parking lots.

The present invention is configured to include a first anchorage member (2), a second anchorage member (3), a tension member (4), and a deflection member (5).

The first anchor (2) and the second anchor (3) are for fixing and fixing both ends of the tension member (4) to the transition wall (11), and are respectively fixed and installed at two spaced apart points of the transition wall (11). do.

The first anchor 2 and the second anchor 3 can be fixed to the transition wall 11 using anchors or the like.

Between the first anchoring port (2) and the second anchoring port (3), a tension member (4) is provided at both ends of which are fixed to the first anchoring port (2) and the second anchoring port (3), respectively.

The tension member 4 may be a strand, steel wire, or steel bar.

After tensioning the tendon member 4 by post-tensioning, prestress is introduced in the vertical direction to the transition wall 11 by anchoring the end of the tendon member 4 to the first anchoring port 2 and the second anchoring port 3.

In this way, by introducing the axial force in the vertical direction to the transition wall 11, the action reaction force can be reduced and the upper load can be transferred to the desired position.

In addition, construction is easy because there is no process of applying or removing the preceding load, and there is no need to install a large support in the underground space to apply the preceding load.

Meanwhile, when introducing tension to the tension member 4 through post-tensioning, short- and long-term loss of tension due to wedge slip of the anchors 2 and 3 and relaxation of the tension member 4 is inevitable.

The loss force generated in the tendon 4 to which tension force is introduced in this way is closely related to the length of the tendon 4, and the shorter the length of the tendon 4, the greater the loss.

In other words, the final tension force introduced into the tendon material 4 after it is settled is a load that takes into account short-term and long-term losses. The shorter the length of the tendon material 4, the greater the loss, and the smaller the amount of tension that can be introduced. .

In particular, when constructing the tension member (4) on the PIT floor during remodeling, the length of the tension member (4) that can be constructed is limited due to restrictions on the floor height (approximately 2.8 m) of the existing structure.

Therefore, a deviator (5) can be used to increase the amount of final tension that can be introduced after tension loss.

The deflection port (5) is installed on the transition wall (11) at a point spaced apart from the virtual connection line connecting the first anchorage port (2) and the second anchorage port (3).

By bending the tension member 4 by hooking the midpoint of the tension member 4 to the deflection hole 5, the length of the tendon member 4 can be increased.

The deflection hole (5) is formed in an arc shape, and the tension member (4) is supported on the outer peripheral surface.

The deflection sphere 5 is preferably used with a curvature of 50D (D=diameter of the tendon) or more to prevent the yielding of the tendon 4 and crushing of the concrete due to bending of the tendon 4.

In the present invention, considering the nominal strength of the transition wall 11 and the load capacity ratio of the existing pile 13, axial force can be introduced by applying prestress as necessary for each part.

That is, the upper load can be transferred to a desired position by adjusting the number, position, installation angle, etc. of the tendons 4.

The tension member 4 may be provided on one side or both sides of the transition wall 11.

The strength ratio of each existing pile 13 is different depending on load distribution, arrangement status of the existing pile 13, etc.

Therefore, the prestress introduction position can be adjusted to selectively reduce the bearing capacity ratio for piles that are expected to have a large increase in bearing capacity ratio due to vertical expansion among the existing piles 13.

For this purpose, part or all of the tendon material 4 can be installed in a vertical direction on the side of the existing pile 13 where the strength ratio needs to be reduced, and the tendon material 4 can be tensioned. As a result, prestress can be intensively introduced along the transition wall 11 on the target existing pile 13 side to reduce the reaction force in that part, thereby reducing the bearing capacity ratio of the target existing pile 13.

In Figure 3, the hatch portion shown on the side of the transition wall 11 represents the change in stress of the transition wall 11.

Figure 4 is a perspective view showing another example of a tension member arranged in an L shape, and Figure 5 is a perspective view showing an embodiment in which an L-shaped tension member is arranged symmetrically left and right.

As shown in FIG. 2, etc., the first anchoring port 2, the second anchoring port 3, and the deflection port 5 may be arranged so that the tendon member 4 forms an L shape.

In FIG. 2, the first anchor (2) is installed on the upper outer side of the transition wall (11), the second anchor (3) is installed on the inner lower part of the transition wall (11), and the deflection port (5) is the first anchor (5). Installed at the lower part of the anchorage (2), the tension member (4) was formed in an L shape.

At this time, the tension member 4 in the portion between the first anchorage hole 2 and the deflection hole 5 is arranged in the vertical direction up and down, thereby reducing the bearing capacity ratio of the existing pile 13 located at the bottom.

As shown in Figure 4, the first anchor (2) is installed in the lower portion of the outer side of the transition wall (11), the second anchor (3) is installed in the upper inner side of the transition wall (11), and the deflection port (5) may be installed above the position of the first anchor (2) to form the tendon (4) in an L shape.

In addition, as shown in FIG. 5, depending on the width of the transition wall 11 or the location of the pile to be reduced in strength ratio, a pair of tendons 4 may be provided in an L-shape symmetrically left and right.

Figure 6 is a perspective view showing an example of a tension member arranged in a U shape, and Figure 7 is a perspective view showing an example of a tension member arranged in an inverted U shape.

As shown in FIG. 6, the first anchor 2, the second anchor 3, and the deflection port 5 may be arranged so that the tension member 4 forms a U shape.

In Figure 6, the first anchor (2) is installed on the upper outer side of the transition wall (11), the second anchor (3) is installed on the upper inner side of the transition wall (11), and the deflection port (5) is the first anchor (5). It was installed in the lower part of the center between the anchorage (2) and the second anchorage (3).

In this case, the left and right portions of the deflection groove 5 of the tendon 4 introduce vertical prestress, respectively.

Alternatively, as shown in FIG. 7, the first anchor (2) and the second anchor (3) are installed on the upper part of the transition wall (11) so that the tension member (4) forms an inverted U shape, and the deflection port (5) It may be installed at the upper part of the center between the first anchorage port (2) and the second anchorage port (3).

Depending on the width of the transition wall 11, a pair of tension members 4 may be provided symmetrically left and right, or one tension member 4 may be provided symmetrically left and right about the deflection hole 5.

FIG. 8 is a perspective view showing an embodiment equipped with a transition frame, and FIG. 9 is an elevation view showing a load transfer process when a transition frame is provided.

As shown in FIGS. 8 and 9, the tension member 4 is provided with a first anchor 2, a second anchor 3, and a deflection hole ( 5) is disposed, and a transition frame (6) is provided at one or both ends of the transition wall (11), and the vertical load transferred to the transition frame (6) is supported on the ground below the transition frame (6). A reinforcing pile 7 may be provided.

Additional reinforcing piles (7) may need to be installed to account for the additional load resulting from vertical expansion. At this time, if reinforcing piles 7 are installed within the existing structure, constructability is greatly reduced and construction time and construction costs are increased.

Therefore, the reinforcing pile 7 can be constructed outside the existing structure, and the load acting on the existing structure can be transferred to the reinforcing pile 7.

For this purpose, a reinforcing pile (7) is installed on the outside of the transition wall (11) to support additional load. And a transition frame (6) connected to the side end of the transition wall (11) is installed on the upper part of the reinforcement pile (7).

At this time, a part of the tension member (4) is placed close to the outer part of the transition wall (11), that is, close to the transition frame (6), so that the prestress introduced into the transition wall (11) by the tension of the tension member (4) is transferred. It can be transferred to the frame (6) side.

When prestress is introduced to the side edge of the transition wall 11, the transition frame 6 acts as a reaction arm to introduce axial force, and the load is transferred to the reinforcement pile 7 below the transition frame 6 (FIG. 9) .

The transition frame 6 can be manufactured from a steel member or a PC member.

When a horizontal extension of a structure is made to the side of an existing structure, the horizontally extended structure can be used as a transition frame (6).

A reinforcing base plate (8) extending from the existing base plate (12) may be installed at the lower part of the transition frame (6) to stably transfer the load of the transition frame (6) to the newly installed reinforcement pile (7). .

As shown in FIGS. 8 and 9, the transition frame 6 may be configured to include an inclined strut 63 whose upper end is fixed to the upper side end of the transition wall 11.

The transition frame (6) transfers the vertical load transferred from the transition wall (11) to the lower reinforcement pile (7). At this time, since the reinforcing pile (7) is installed at a certain distance from the existing structure, the transition frame (6) is inclined in order to transfer the load of the transition wall (11) to the reinforcing pile (7) by the vertical component. It can be configured to include a strut (63).

The top of the strut 63 may be coupled to the side end of the transition wall 11 at a height corresponding to the height of the top of the tension member 4 installed on the transition wall 11.

The strut 63 is provided at an angle and can be located at the top of the reinforcement pile 7 whose lower end is newly installed.

The transition frame 6 may be composed of a plurality of layers in consideration of the height of the anchorage where the top of the tension member 4 is anchored, the size of the transition frame 6, etc.

In this case, in order to support and transmit the horizontal and vertical components of the strut 63, the transition frame 6 may be configured in the form of a truss by including vertical members 61 and horizontal members 62.

1: Existing wall
11: Transition wall
12: Existing base plate
13: Existing file
2: First settlement
3: Second Settlement
4: tension material
5: Pyeongyang-gu
6: Transition frame
61: Vertical material
62: horizontal material
63: strut
7: Reinforcement pile
8: Reinforced base plate

Claims (5)

It is installed on the transition wall 11, which is the lower underground part of the existing wall 1, in order to adjust the load capacity ratio of the existing pile 13, which transfers the upper load from the vertically expanded structure and supports the structure.
A first anchor (2) and a second anchor (3) respectively fixed and installed at two points spaced apart from each other on the transition wall (11);
Tension material, both ends of which are respectively fixed to the first anchor (2) and the second anchor (3), introduces prestress in the vertical direction through post-tension to the transition wall (11) and introduces axial force in the vertical direction, thereby reducing the action reaction force. (4); and
A deflection port (5) provided on the transition wall (11) at a point spaced apart from the connection line between the first anchor (2) and the second anchor (3) to bend the tension member (4); It consists of,
The first anchor (2), the second anchor (3), and the deflection port (5) have a tension material (4) formed in an L or U shape, so that the vertical portion of the tension material (4) is an existing pile ( 13) A load transfer system for vertical expansion using post-tension, characterized in that it is arranged to be located on the side.
delete delete In paragraph 1:
The first anchor (2), the second anchor (3), and the deflection port (5) are arranged so that the tension member (4) applies prestress in the vertical direction to the outer side of the transition wall (11),
A transition frame (6) is provided at one or both ends of the transition wall (11), and a reinforcing pile (7) is provided in the ground below the transition frame (6) to support the vertical load transferred to the transition frame (6). A load transfer system for vertical expansion using post-tension, characterized in that it is provided.
In paragraph 4,
The transition frame (6) is a load transfer system for vertical expansion using post-tension, characterized in that it includes an inclined strut (63) whose upper end is fixed to the upper side end of the transition wall (11).

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