JP7392697B2 - Subsidence correction method for steel pipe members and buildings - Google Patents

Description

The present invention relates to a steel pipe member and a method for correcting subsidence of a building.

Techniques for correcting the inclination of buildings due to uneven ground subsidence are known.
Patent Document 1 discloses the following matters. A hole is dug under a predetermined part of the building's foundation, a steel pipe pile is placed at the bottom of the hole, and the steel pipe pile is pressed into the ground using a hydraulic jack. This process is repeated by sequentially connecting new steel pipe piles until the first steel pipe pile reaches the support layer. After the piles have been driven at a plurality of predetermined locations on the foundation, a pedestal is welded to the upper end of the steel pipe pile, a hydraulic jack is placed on the pedestal, and the building is leveled by the hydraulic jack. After this, replace the hydraulic jack with a journal jack. After the ground has cured, the inclination of the building will be adjusted using journal jacks. Then, a tubular spacer with a length matching the distance from the pedestal to the bottom surface of the foundation is attached next to the journal jack, welded to the top surface of the pedestal, and the journal jack is removed. After that, the area around the tubular spacer is fixed with mortar, etc., and the hole is backfilled with earth and sand.

Japanese Patent Application Publication No. 8-27829

By the way, in the case of conventional correction methods for buildings, after correcting the inclination of the foundation, the building consists of a pile made up of a plurality of steel pipes, a pedestal installed at the top of the pile, and a pedestal and the bottom surface of the foundation. and a support member disposed between them. The support member is fixed to the pedestal, but is not directly connected to the stake. For this reason, there is a possibility that the strength of a pile obtained by the conventional straightening method will be lower than the strength of a pile in which steel pipes are continuous under the foundation. From this point of view, there is room for improvement in the structure of piles and the method for correcting settlement of buildings.

(1) A steel pipe member that solves the above problem is a steel pipe member that connects two steel pipes, and includes a member main body and a pedestal that supports a jack, and the member main body has the same diameter as a steel pipe pile. The cradle has a receiving plate portion having a surface perpendicular to the side surface of the member main body, and the receiving plate portion is provided so as to protrude from the side surface of the member main body.

According to this configuration, the jack can be placed on the pedestal of the steel pipe member while the steel pipe member is connected to the steel pipe buried in the ground. Furthermore, a steel pipe can be connected to the member body of the steel pipe member. In this way, since the steel pipe can be connected to the member main body, the strength of the steel pipe pile can be improved compared to the case where a plate member is interposed between the steel pipe member and the steel pipe.

(2) In the steel pipe member of (1) above, a stopper for stopping the backing ring is provided on the inner peripheral surface of the member main body. According to this configuration, the backing ring can be placed at a predetermined position with respect to the member main body.

(3) A building settlement correction method that solves the above problem is a building settlement correction method in which a steel pipe pile including a steel pipe member is installed in the ground, the steel pipe member being formed by a steel pipe having the same diameter as the steel pipe pile. a first step of providing a hole at a location where the steel pipe pile is to be pushed under the foundation of the building; a second step of pushing the steel pipe until it reaches a support layer; a third step of connecting the steel pipe member to the steel pipe last connected in the second step; and placing a jack on the steel pipe member. a fourth step of adjusting the inclination of the building; and a fifth step of connecting the steel pipe that matches the distance between the steel pipe member and the foundation to the member body of the steel pipe member after adjusting the inclination of the building. process.

According to this configuration, the foundation can be supported by the steel pipe pile having the steel pipes connected to each other in the vertical direction. This facilitates the direct transmission of the building load to the support layer.

(4) In the method for correcting settlement of a building, the steel pipe member has a stopper on the inner circumferential surface of the steel pipe member for stopping a backing ring, and in the fifth step, the steel pipe member and the foundation are connected to each other. When connecting the steel pipe to the steel pipe member at a distance of The backing ring is placed in position by dropping the backing ring. According to this configuration, the steel pipe and the steel pipe member can be connected to each other by welding via the backing ring arranged at a predetermined position.

(5) In the method for correcting settlement of a building, in the fifth step, a gap is provided between the upper end of the member main body and the lower end of the steel pipe disposed between the member main body and the foundation. In this state, the upper end of the member main body and the lower end of the steel pipe are welded. According to this configuration, the steel pipe and the steel pipe member can be firmly connected.

According to the steel pipe member and building settlement correction method of the present disclosure, the strength of the steel pipe pile can be improved.

A perspective view of a steel pipe member. A cross-sectional view of the ground with a hole provided under the foundation. A cross-sectional view of the ground where a steel pipe is being pushed in by a hydraulic jack. A cross-sectional view of the ground where a new steel pipe will be placed. A sectional view of the ground in a state where a steel pipe member is connected to a steel pipe. A sectional view of the ground with an adjustment jack placed on a steel pipe member. An enlarged view of the vicinity of the steel pipe member in which the steel pipe is placed on the steel pipe member. FIG. 3 is an enlarged view of the vicinity of the steel pipe member in a state where the steel pipe is placed on the steel pipe member and the backing ring is placed in a predetermined position. A cross-sectional view of the ground after the hole has been backfilled.

<Steel pipe members and steel pipe piles>
With reference to FIG. 1, a steel pipe member 20 of this embodiment will be described.
A building 3 is built on a foundation 2 provided on the ground 1. When the ground 1 is soft, the weight of the building 3 causes uneven settlement of the ground 1, causing the building 3 to lean. In such a case, steel pipe piles 10 are buried in the ground 1 for the purpose of correcting the inclination of the building 3. The building 3 is supported by steel pipe piles 10. In one example, a plurality of steel pipe piles 10 are buried under the foundation 2, and the building 3 is supported by the plurality of steel pipe piles 10. The steel pipe pile 10 is configured to reach the support layer. The steel pipe member 20 is one of the components of the steel pipe pile 10.

The steel pipe pile 10 is divided into a plurality of elements so as to fit into the hole 4 provided under the foundation 2. Specifically, the steel pipe pile 10 includes a plurality of steel pipes 11 and a steel pipe member 20. The steel pipe 11 has a cylindrical shape. The steel pipe pile 10 is configured by connecting one or more steel pipes 11, a steel pipe member 20, and a steel pipe 11 (hereinafter also referred to as steel pipe 11A) disposed on the steel pipe member 20. The steel pipe member 20 is placed second from the top in the steel pipe pile 10. Steel pipes 11 are pushed into the ground 1 one by one. Another steel pipe 11 is added to the steel pipe 11 pushed into the ground 1. The pile to which the steel pipes 11 have been added (that is, the pile made of a plurality of steel pipes 11) is further pushed into the ground 1, thereby advancing deeper toward the support layer.

The steel pipe member 20 connects the two steel pipes 11. Specifically, the steel pipe member 20 is arranged between the steel pipe 11A arranged under the foundation 2 and the uppermost steel pipe 11 of the steel pipes 11 buried in the ground 1, and Then, the two steel pipes 11 are connected. The steel pipe member 20 supports the adjustment jack 31. In one example, a support jack 40 is used as the adjustment jack 31. The support jack 40 has a cylindrical body 41 and a bolt 42 that moves forward and backward with respect to the cylindrical body 41 (see FIG. 7). A nut 43 is engaged with the bolt 42. By arranging the nut 43 on the bolt 42 at a position where it contacts the cylindrical body 41, the position of the bolt 42 with respect to the cylindrical body 41 is fixed.

As shown in FIG. 1, the steel pipe member 20 includes a member main body 21 and a pedestal 22 that supports a jack. The member body 21 has a cylindrical shape. The member main body 21 is made of a steel pipe having the same diameter as the steel pipe 11 of the steel pipe pile 10.

The pedestal 22 has a receiving plate portion 23 having a surface perpendicular to the side surface 21A of the member main body 21. The receiving plate portion 23 is provided so as to protrude from the side surface 21A of the member main body 21.
In one example, the member main body 21 has two pedestals 22. One pedestal 22 is provided on the opposite side of the other pedestal 22 with respect to the member main body 21. The two pedestals 22 extend in a radial direction relative to the center line C of the member body 21 with respect to the member body 21 . The pedestal 22 connects the receiving plate part 23, a lower plate part 24 arranged parallel to the receiving plate part 23 with a space under the receiving plate part 23, and the receiving plate part 23 and the lower plate part 24. It includes a vertical plate part 25 and an oblique part 26. The receiving plate portion 23, the lower plate portion 24, and the vertical plate portion 25 are made of H-shaped steel or the like. The receiving plate part 23, the lower plate part 24, and the vertical plate part 25 are connected to the member main body 21 by welding. The oblique portion 26 is provided diagonally with respect to the side surface 21A of the member main body 21 and the lower plate portion 24. The diagonal portion 26 is welded to the side surface 21A of the member body 21 and the lower surface of the lower plate portion 24. The lower plate portion 24 is supported by an oblique portion 26 .

The receiving plate portion 23 is provided at a predetermined distance from the upper end 21B of the member main body 21. This makes it easier to connect the steel pipe 11A disposed on the steel pipe member 20 and the steel pipe member 20. In one example, the steel pipe 11A is connected to the steel pipe member 20 by welding.

A backing ring 36 is used when the steel pipe 11A and the steel pipe member 20 are connected by welding (see FIG. 8). The backing ring 36 is arranged inside the connection portion between the steel pipe 11A and the steel pipe member 20 when the steel pipe 11A disposed on the steel pipe member 20 and the steel pipe member 20 are connected.

In the steel pipe member 20, a stopper 27 for stopping the backing ring 36 is provided on the inner peripheral surface of the member main body 21. The stopper 27 is provided on the inner peripheral surface of the member main body 21 by welding. The stopper 27 is used as follows. Before placing the steel pipe 11A on the steel pipe member 20, the backing ring 36 is placed inside the steel pipe 11A in advance. When the steel pipe 11A is placed on the steel pipe member 20, the backing ring 36 falls off. The stopper 27 receives the backing ring 36 falling from the steel pipe 11A (see FIG. 8). The stopper 27 is configured such that the backing ring 36 extends between the steel pipe 11A and the member main body 21 in a state where the backing ring 36 is supported by the stopper 27.

<Method for correcting building subsidence>
A method for correcting subsidence of the building 3 will be explained with reference to FIGS. 2 to 9. 2 to 4 are cross-sectional views of the ground 1 and the foundation 2 seen from a predetermined direction, and FIGS. FIG. The method for correcting the subsidence of the building 3 is a method used for the purpose of correcting the inclination of the building 3 when the inclination of the building 3 occurs due to uneven subsidence of the ground 1. In the method for correcting subsidence of a building 3, a steel pipe pile 10 including a steel pipe member 20 is provided on the ground 1. The steel pipe member 20 has the structure shown above.

Before the process of straightening the building 3, the amount of settlement of the building 3 is measured in advance. The location where the steel pipe pile 10 is pushed is determined based on the amount of subsidence of the building 3. In one example, steel pipe piles 10 are driven under each of a plurality of locations on the foundation 2.

The step of straightening the building 3 includes at least five steps.
As shown in FIG. 2, in the first step, a hole 4 is provided under the foundation 2 of the building 3 at a location where the steel pipe pile 10 will be driven. In one example, the depth of the hole 4 is 0.5 m or more and 2 m or less.

As shown in FIGS. 3 and 4, in the second step, the steel pipes 11 are pushed in while connecting them until the first steel pipe 11 pushed in reaches the support layer.
Specifically, the steel pipe 11 is erected at the bottom of the hole 4 provided under the foundation 2. Next, a hydraulic jack 30 is placed between the upper end of the steel pipe 11 and the lower surface of the foundation 2, and the upper end of the hydraulic jack 30 is attached to the lower surface of the foundation 2. By jacking up the hydraulic jack 30, the load of the building 3 is transmitted to the steel pipe 11, and the steel pipe 11 is pushed into the ground 1. When the top surface of the steel pipe 11 is located near the bottom surface of the hole 4, a new steel pipe 11 is connected to the steel pipe 11 buried in the ground 1 by welding. Then, in the same manner as the first steel pipe 11, the pile made longer by connecting the steel pipes 11 is pushed into the ground 1 by the hydraulic jack 30. The connection work of connecting a new steel pipe 11 to the steel pipe 11 pushed into the ground 1 is repeated until the first steel pipe 11 reaches the support layer. Whether the first steel pipe 11 has reached the support layer is determined based on whether the steel pipe 11 is pushed into the ground 1 by the hydraulic jack 30 or not. When the foundation 2 is lifted up by the hydraulic jack 30, it is determined that the first steel pipe 11 has reached the support layer.

As shown in FIG. 5, in the third step, the steel pipe member 20 is connected to the steel pipe 11 that was last connected in the second step. Specifically, the member main body 21 of the steel pipe member 20 is connected to the steel pipe 11 so that the pedestal 22 of the steel pipe member 20 is located under the foundation 2. At this time, a hydraulic jack 30 may be placed on the member main body 21 of the steel pipe member 20, and the building 3 may be jacked up so that the inclination of the building 3 becomes horizontal. The connection between the member main body 21 of the steel pipe member 20 and the steel pipe 11 is similar to the connection between the steel pipes 11, and is performed by welding.

In the fourth step, the inclination of the building 3 is adjusted using the hydraulic jack 30 installed on the steel pipe member 20. After jacking up, an adjustment jack 31 is placed between the receiving plate portion 23 of the pedestal 22 and the lower surface of the foundation 2 in each of the two pedestals 22. Then, the rod of the adjusting jack 31 is attached to the lower surface of the foundation 2 via the iron plate 35. A support jack 40 is used as the adjustment jack 31.

As shown in FIG. 6, after the adjustment jack 31 is placed, the hydraulic jack 30 is removed. Thereafter, with the foundation 2 supported by the adjustment jack 31, the ground 1 is cured for a while. The steel pipe pile 10 is stabilized by digging into the support layer during the curing period. After the curing period, the inclination of the building 3 is adjusted. Specifically, the inclination of the building 3 is finely adjusted by jacking up or jacking down the adjustment jack 31.

As shown in FIG. 7, in the fifth step, after adjusting the inclination of the building 3, a steel pipe 11A that matches the distance between the steel pipe member 20 and the foundation 2 is placed between the steel pipe member 20 and the foundation 2. Then, the steel pipe 11A is connected to the member main body 21 of the steel pipe member 20. The length of the steel pipe 11A is slightly shorter than the distance between the steel pipe member 20 and the foundation 2. A steel pipe 11A that matches the distance between the steel pipe member 20 and the foundation 2 is created by cutting the steel pipe 11 of a predetermined length.

When connecting the steel pipe 11A to the steel pipe member 20, a backing ring 36 is placed within the steel pipe 11A. Then, the steel pipe 11A is placed between the member main body 21 of the steel pipe member 20 and the foundation 2 with the backing ring 36 placed inside the steel pipe 11A. When the center of the steel pipe 11A and the center of the member main body 21 are aligned, the backing ring 36 falls to the position of the stopper 27, and the backing ring 36 is received by the stopper 27. In this way, the backing ring 36 is placed at a predetermined position with respect to the member body 21 of the steel pipe member 20 and the steel pipe 11A. Specifically, the backing ring 36 is arranged to span the member main body 21 and the steel pipe 11A.

Next, as shown in FIG. 8, the upper end of the steel pipe 11A is brought into contact with the lower surface of the foundation 2. In this case, a gap of approximately several mm to 10 mm is created between the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A. The upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A are arranged so that a gap is maintained between the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A. A wedge or spacer 37 is placed in between. Then, with a gap provided between the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A, the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A are welded. . After this, the adjustment jack 31 may be removed.

As shown in FIG. 9, after removing the adjusting jack 31, the portion of the foundation 2 that the steel pipe pile 10 contacts is hardened with concrete 7 or the like. For example, a formwork 8 is installed around the lower part of the foundation 2 and the steel pipe 11A placed under the foundation 2, the formwork 8 is filled with concrete 7, etc., and the concrete 7 etc. is hardened. After this, the hole 4 is backfilled with soil or sandbags 6.

The operation of this embodiment will be explained.
The member main body 21 of the steel pipe member 20 has the same structure as the steel pipe 11. Further, the steel pipe member 20 connects the steel pipe 11 arranged below the steel pipe member 20 and the steel pipe 11A arranged above the steel pipe member 20. Further, the steel pipe member 20 includes a pedestal 22. For this reason, after installing a steel pipe member 20 on the steel pipe 11 buried in the ground 1 and adjusting the inclination of the building 3 with a hydraulic jack 30 placed on the steel pipe member 20, the steel pipe 11A is placed between the steel pipe member 20 and the foundation 2. can be arranged to connect the steel pipe 11A and the steel pipe member 20. The member main body 21 of the steel pipe member 20 has the same structure as the steel pipe 11. Therefore, the steel pipe pile 10 becomes a single structure in which steel pipes 11 of the same structure are connected. This structure makes it easier for the load of the building 3 to be directly transmitted to the support layer. It also has the following effects. In the conventional steel pipe pile structure, calculation of the bearing capacity of the steel pipe pile 10 was complicated because it was not continuous. However, in the structure of the steel pipe pile 10 of this embodiment, the bearing capacity of the steel pipe pile 10 can be calculated as one continuous pile. Therefore, the steel pipe pile 10 of this embodiment has the advantage that the bearing capacity can be easily calculated.

The effects of this embodiment will be explained.
(1) The steel pipe member 20 includes a member main body 21 and a pedestal 22 that supports the adjustment jack 31. The member main body 21 is made of a steel pipe having the same diameter as the steel pipe 11 of the steel pipe pile 10. The pedestal 22 has a receiving plate portion 23 having a surface perpendicular to the side surface 21A of the member main body 21. The receiving plate portion 23 is provided so as to protrude from the side surface 21A of the member main body 21.

According to this configuration, the jack can be placed on the pedestal 22 of the steel pipe member 20 in a state where the steel pipe member 20 is connected to the steel pipe 11 buried in the ground 1. Furthermore, the steel pipe 11A can be connected to the member main body 21 of the steel pipe member 20. In this way, since the steel pipe 11A can be connected to the member main body 21, the strength of the steel pipe pile 10 can be improved compared to the case where a plate member is interposed between the steel pipe member 20 and the steel pipe 11A.

(2) A stopper 27 for stopping the backing ring 36 is provided on the inner peripheral surface of the member main body 21. According to this configuration, the backing ring 36 can be placed at a predetermined position with respect to the member main body 21.

(3) The method for correcting subsidence of the building 3 includes at least a fourth step and a fifth step. In the fourth step, a hydraulic jack 30 is placed on the steel pipe member 20 to adjust the inclination of the building 3. Thereafter, the adjustment jack 31 is placed on the pedestal 22 to support the building 3. In the fifth step, after adjusting the inclination of the building 3, a steel pipe 11A that matches the distance between the steel pipe member 20 and the foundation 2 is inserted, and the steel pipe 11A is connected to the member body 21 of the steel pipe member 20. The member main body 21 is made of a steel pipe having the same diameter as the steel pipe 11 of the steel pipe pile 10.

According to this configuration, the foundation 2 can be supported by the steel pipe pile 10 having the steel pipes 11 connected to each other in the vertical direction. This makes it easier for the load of the building 3 to be directly transmitted to the support layer.

(4) In the fifth step, with the backing ring 36 placed inside the steel pipe 11A, the steel pipe 11A is placed between the member body 21 and the foundation 2, the backing ring 36 is dropped to the stopper 27, and the backing ring 36 is placed inside the steel pipe 11A. Place the abutment ring 36 in a predetermined position. According to this configuration, the steel pipe 11A and the steel pipe member 20 can be connected to each other by welding via the backing ring 36 arranged at a predetermined position.

(5) In the fifth step, a gap is provided between the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A arranged between the member main body 21 and the foundation 2. With a gap provided between the member body 21 and the steel pipe 11A in this manner, the upper end 21B of the member body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A are welded. According to this configuration, the steel pipe 11A and the steel pipe member 20 can be firmly connected.

<Modified example>
The embodiment described above is an example of the form that the method for correcting subsidence of the steel pipe member 20 and the building 3 can take, and is not intended to limit the form. The method for correcting the subsidence of the steel pipe member 20 and the building 3 may take a different form from the form illustrated in the above embodiment. An example thereof is a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment. An example of a modification of the embodiment is shown below.

- The means for connecting the steel pipes 11 to each other is not limited to welding. The steel pipes 11 may be connected to each other by coupling a screw along the periphery of the upper end of the steel pipe 11 with a screw along the periphery of the lower end of the steel pipe 11. The steel pipes 11 may be connected to each other by bolts. When using bolts, a ring-shaped connecting member along the circumference of the steel pipe 11 is used. The connecting member and the steel pipe 11 are fastened with bolts. Further, the connecting member and the steel pipe member 20 are fastened with bolts. The means for connecting the steel pipe 11A and the steel pipe member 20 may also be performed by screw connection, as described above, or by using bolts and connection members.

- The structure of the stopper 27 of the above embodiment is not limited. The stopper 27 may be formed by a bolt. For example, the bolt is configured to be inserted through a through hole that penetrates the member body 21. The bolt is fixed to the member body 21 by a nut attached to the bolt so as to contact the inner peripheral surface of the member body 21. In this case, the portion of the bolt that protrudes from the inner circumferential surface of the member main body 21 and the nut serve as the stopper 27.

- In the above embodiment, a gap is provided between the upper end 21B of the member main body 21 of the steel pipe member 20 and the lower end 11B of the steel pipe 11A. On the other hand, the member body 21 of the steel pipe member 20 and the steel pipe 11A may be welded by eliminating such a gap and bringing the lower end 11B of the steel pipe 11A into contact with the upper end 21B of the member body 21 of the steel pipe member 20. . In this case, a gap is created between the steel pipe 11A and the lower surface of the foundation 2. An iron plate or wedge is inserted into this gap.

1...Ground 2...Foundation 3...Building 4...Hole 10...Steel pipe pile 11...Steel pipe 11A...Steel pipe 20...Steel pipe member 21...Member body 22...Base 23...Base plate part 27...Stopper 31...Adjustment jack 36...Back guess ring

Claims (3)

A steel pipe member that connects two steel pipes,
Comprising a member main body and a cradle for supporting a jack,
The member main body is composed of a steel pipe having the same diameter as the steel pipe pile,
A stopper for stopping the backing ring is provided on the inner peripheral surface of the member main body,
The pedestal has a receiving plate portion having a surface perpendicular to the side surface of the member main body, and the receiving plate portion is provided so as to protrude from the side surface of the member main body.
Steel pipe parts. A method for correcting settlement of a building in which steel pipe piles including steel pipe members are installed in the ground,
The steel pipe member has a member main body made of a steel pipe having the same diameter as the steel pipe pile, and a pedestal provided on the member main body,
The steel pipe member has a stopper on an inner circumferential surface of the steel pipe member for stopping a backing ring,
A first step of providing a hole under the foundation of the building at a location where the steel pipe pile is to be pushed;
a second step of pushing the steel pipe while connecting the steel pipe until the steel pipe pushed first reaches the support layer;
a third step of connecting the steel pipe member to the steel pipe last connected in the second step;
a fourth step of adjusting the inclination of the building by placing a jack on the steel pipe member;
After adjusting the inclination of the building, with the backing ring placed within the steel pipe, the steel pipe is placed between the member body and the foundation in a manner that matches the distance between the steel pipe member and the foundation. and a fifth step of dropping the backing ring to the stopper, arranging the backing ring at a predetermined position, and connecting the steel pipe to the member body of the steel pipe member.
Method for correcting building subsidence. In the fifth step, the upper end of the member body and the lower end of the steel pipe arranged between the member body and the foundation are provided with a gap between the upper end of the member body and the lower end of the steel pipe arranged between the member body and the foundation. The method for correcting settlement of a building according to claim 2 , wherein the lower end is welded.

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