Push-up construction method and push-up device for structures

Abstract

This invention provides a push-up method and apparatus that allows for the stable and safe lifting of existing main columns that have been cut and left suspended in mid-air during raising work on existing structures supported by cantilevered columns. [Solution] With the beam member 5 temporarily fixed to the side of the self-supporting column 4, the hydraulic jack 7 is supported at its lower end by a jack receiving member 9 installed on the side of the self-supporting column 4. Next, the temporary fixing of the beam member 5 is released, the piston rod 7a of the hydraulic jack 7 is extended, and using the self-supporting column 4 as a guide rail, all of the existing main columns 2 are lifted simultaneously, and at a predetermined height position, the beam member 5 is temporarily fixed again to the side of the self-supporting column 2. Next, the hydraulic jack 7 separates its lower end from the jack receiving member 9, and the piston rod 7a is retracted and rises. The above procedure is repeated until the final target height is reached.

Description

Technical Field

[0001] The present invention relates to a push-up method and an apparatus used in raising work for increasing the floor height of an existing structure.

Background Art

[0002] Conventionally, in the construction of a structure, when assembling and lifting the structure at a low position, a push-up method using a hydraulic jack may be used.

[0003] In addition, in raising work for increasing the floor height of an existing structure, since an existing main pillar is cut and a new member is added, when the push-up method is used, it is required to stably hold the existing main pillar in a suspended state and lift the entire building.

[0004] For example, existing main pillars of a large-span structure such as an existing large exhibition hall or a shipping area of a market may be cantilever columns with their column heads pin-jointed to a roof structure and their column feet as fixed column feet. When such an existing structure is raised (see Fig. 1), since there is no rotational restraint at the upper and lower ends of the cut existing main pillar, the existing main pillar in a suspended state becomes unstable when only vertically supported, so a device for restraining rotation together with horizontal movement is required.

[0005] As a prior art of a push-up method for lifting a structure, for example, there is an invention described in Patent Document 1. The invention described in Patent Document 1 discloses a push-up method in which a telescopic support formed by fitting a plurality of pipe members with different diameters disposed in a shed-shaped guide tower constructed on the ground is sequentially drawn out and lifted from the outermost pipe member by a lifting member installed on the guide tower, and a structure such as a roof supported by the telescopic support is lifted.

[0006] The invention described in Patent Document 1 ensures that the roof frame is directly supported by the expansion support, thus maintaining stability even during the lifting process. When raising an existing structure using this method, the expansion support first supports the beam portion of the roof frame, the existing main columns are cut, the expansion support is extended upward, and new members of the required length are added to the existing main columns while the predetermined height is maintained.

[0007] However, it is clear that this method cannot be applied when it is difficult to support the beam section of the roof frame when raising an existing structure. In other words, it cannot be applied under the condition of directly supporting the existing main column that has been cut and lifting the existing structure, and Patent Document 1 does not describe or suggest the problem of stably lifting an existing main column that has been cut and is suspended in mid-air, nor does it suggest a solution to this problem. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 3379014 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention provides a push-up method and push-up device that, when raising an existing structure in which the top of the existing main column is pinned to the roof frame and the base of the column is supported by a cantilevered column which is a fixed column base, allows the existing main column, which has been cut and is suspended in mid-air, to be stably held and safely lifted. [Means for solving the problem]

[0010] To solve the aforementioned problem, the present invention relates to raising an existing structure supported by a cantilever column, in which the column head of the existing main column is pin-connected to the roof frame and the column base is a fixed column base. 1) Self-supporting columns fixed to their bases are arranged in close proximity to the existing main columns of the existing structure, as pairs of columns in a straight line including the existing main columns in a plan view, at least two pairs of such columns intersect at predetermined intervals. 2) Above the point where the existing main column is cut, beam members of a predetermined length are attached to the side of the existing main column in at least four directions so as to face the self-supporting column, and a gap is ensured between the side of the self-supporting column and the tip surface of the beam members so as not to come into contact.

[0011] 3) At least one pair of hydraulic jacks are vertically installed between the lower end of the beam member and directly below it, between the upper surface of the base of the column of the self-supporting column, as a pair of jacks in a straight line including the existing main column in a plan view, and the hydraulic jacks apply an upward force equivalent to the vertical load (axial force) acting on the existing main column. 4) While supported by the hydraulic jack, the existing main column is cut at an appropriate position at its lower part.

[0012] 5) After the existing main columns are cut, the piston rod of the hydraulic jack is extended, and the existing main columns are all simultaneously lifted to a predetermined height, using the self-supporting columns as guide rails. 6) At a predetermined height position where the existing main column has been lifted, the beam member is temporarily fixed to the side of the self-supporting column. 7) The hydraulic jack is raised when its lower end is separated from the upper surface of the column base of the self-supporting column and the tip of the piston rod is connected to the lower end of the beam member, and the piston rod is retracted.

[0013] 8) A jack receiving member is installed on the side of the self-supporting column at the lower end position of the hydraulic jack once it has finished rising, and the lower end of the hydraulic jack is connected to it. 9) Next, the temporary fixing of the beam member is released, the piston rod is extended again, and using the self-supporting column as a guide rail, all of the existing main columns of the existing structure are simultaneously raised to a predetermined height, and at the predetermined height position, the beam member is temporarily fixed again to the side of the self-supporting column. 10) Next, the hydraulic jack is raised as the piston rod is retracted, with its lower end separated from the jack receiving member and the tip of the piston rod connected to the lower end of the beam member.

[0014] 11) The steps in 8) to 10) above are repeated until the final target height is reached. 12) After reaching the final target height, the vertical load from the existing main column is transferred to the self-supporting column via the hydraulic jack after the lower end of the hydraulic jack is connected to the jack receiving member which has been reinstalled on the side of the self-supporting column, and the temporary fixing of the beam member is released. 13) After the vertical load from the existing main column is transferred to the self-supporting column, the existing main column is lifted and the extension member is inserted into the lifted section secured, rigidly joined to the existing main column and integrated with it, and all the beam members are permanently joined to the opposing self-supporting column, and the existing main column to which the extension member has been added and the self-supporting column are integrated as a framework. This is a structural push-up method characterized by including the above steps. Note that temporary materials such as hydraulic jacks and jack support members will be removed after step 13).

[0015] Furthermore, in the push-up construction method for the structure, the arrangement of pairs of hydraulic jacks, which are placed around the existing main column in close proximity and on a straight line including the existing main column in a plan view, may not be in the same direction for all of the existing main columns.

[0016] Furthermore, the present invention relates to a device used in the push-up method for the aforementioned structure, 1) In close proximity to the existing main column of the existing structure, self-supporting columns fixed to their bases are arranged at predetermined intervals so that at least two sets of such columns intersect, forming pairs of columns on a straight line including the existing main column in a plan view. 2) Above the position where the existing main column is cut, beam members with a predetermined length in at least four directions are rigidly joined to the side surface of the existing main column so as to face the self-supporting column, and a gap is secured between the side surface of the self-supporting column and the tip surface of the beam member such that they do not contact each other. Also, a rotation stopper for preventing the horizontal rotation of the tip surface of the beam member accompanying the rotation of the existing main column around its column axis is installed. A friction reduction material for reducing the frictional resistance when the tip surface of the beam member contacts the side surface of the self-supporting column may be provided in the gap.

[0017] 3) Between the lower end of the beam member and the upper surface of the column foot of the self-supporting column directly below it, at least one set of hydraulic jacks is installed vertically as a set of two jacks on a straight line including the existing main column in plan view. 4) The hydraulic jack having a piston rod is installed with its lower end on the upper surface of the column foot of the self-supporting column or on a jack receiving member installed on the side surface of the self-supporting column, and the tip of the piston rod is connected to the lower end of the beam member.

[0018] 5) The hydraulic jack has a capacity necessary to extend the piston rod and lift all of the existing main columns of the existing structure simultaneously in a state where the existing main column is cut. A push-up device used in a push-up method for a structure, characterized by including the above configuration.

[0019] Also, the following operations are made possible by this device. 6) In a state where the existing main column is cut, the beam member is temporarily fixed to the side surface of the self-supporting column at a predetermined height position where the piston rod of the hydraulic jack installed with its lower end on the upper surface of the column foot of the self-supporting column is extended and the existing main column is lifted. During the ascent of the existing main column, the horizontal rotation of the tip surface of the beam member is prevented by the rotation stopper. 7) In the state of 6) above, the hydraulic jack is such that its lower end is separated from the upper surface of the column leg portion of the self-standing column, and the piston rod is retracted and raised with the tip of the piston rod connected to the lower end portion of the beam member.

[0020] 8) After the hydraulic jack has completed rising, a jack receiving member connected to the lower end of the hydraulic jack is installed on the side surface of the self-standing column, and the lower end of the hydraulic jack is connected and supported. 9) Following 8) above, the temporary fixing of the beam member is released, the piston rod is extended, and all of the existing main columns are simultaneously lifted up to a predetermined height. At the predetermined height position, the beam member is temporarily fixed again to the side surface of the self-standing column. 10) Following 9) above, the hydraulic jack is such that its lower end is separated from the jack receiving member, and the piston rod is retracted and raised again with the tip of the piston rod connected to the lower end portion of the beam member. 11) Subsequently, the procedures of 8) to 10) are repeated until the final target height is reached.

[0021] 12) In the state where the final target height has been reached by the jacking-up, the vertical load from the existing main columns transmitted to the self-standing column via the beam member is transmitted to the self-standing column via the hydraulic jack after the lower end of the hydraulic jack is connected to the jack receiving member installed on the side surface of the self-standing column and the temporary fixing of the beam member is released.

[0022] Since the present invention is a construction method and apparatus as described above, for the cut existing main columns, the beam member is vertically supported by the hydraulic jack, and the self-standing column opposite to the front end surface of the beam member serves as a guide rail, so horizontal movement, inclination, and horizontal rotation around the axis of the existing main columns are suppressed even while being lifted by the piston rod.

[0023] Although a gap is ensured between the side surface of the self-supporting column and the tip surface of the beam member to prevent contact, it is desirable to provide a friction-reducing material in the gap so that the frictional resistance caused by contact between the side surface of the self-supporting column and the tip surface of the beam member while the existing main column is rising is reduced.

[0024] Furthermore, even if the gap between the side surface of the self-supporting column and the tip surface of the beam member is small, the existing main column is suspended in mid-air, so some tilt will occur. However, by adjusting the pair of hydraulic jacks positioned on either side of the existing main column, it is possible to maintain a vertical position.

[0025] Furthermore, regarding the inclination of the existing main column in the direction without the hydraulic jack, if the vertical dimension of the tip surface of the beam member attached in that direction is sufficiently high, the rotation angle relative to the small gap with the side surface of the self-supporting column can be kept to a negligible degree. Possible solutions include increasing the depth of the beam member, or attaching a rotation suppression member to the lower or upper end near the tip of the beam member so as to be opposite the side surface of the self-supporting column. Of course, another pair of hydraulic jacks may be added in the direction where there are no hydraulic jacks to adjust the inclination of the existing main column.

[0026] Furthermore, by integrating the existing main columns and the self-supporting columns as a framework, the structure, whose floor height has been increased by the raising, is reinforced against vertical loads and horizontal loads such as earthquakes. [Effects of the Invention]

[0027] Because the present invention employs the means described above, the following effects can be obtained in construction work to raise existing structures. (1) Self-supporting columns that serve as reinforcing columns are installed in advance as part of the push-up device in close proximity to the existing main columns of the existing structure, which is effective in ensuring safety against horizontal loads during the raising process, and can also be used as guide rails. (2) Since the freestanding columns are installed in close proximity to the existing main columns, the newly constructed column bases and foundations for the freestanding columns can also be used to reinforce the column bases and foundations of the existing main columns. (3) Since the self-supporting columns form the permanent framework that is integrated with the existing main columns, the amount of temporary materials used is reduced, and the effort required to remove them is also eliminated, thus reducing temporary construction costs. (4) The self-supporting columns serve as guide rails when lifting the existing main columns and also help to prevent the existing main columns from tilting while suspended, thus greatly contributing to ensuring accuracy upon completion. [Brief explanation of the drawing]

[0028] [Figure 1] This is an illustrative diagram explaining the raising of existing structure 1. [Figure 2] This diagram illustrates the procedure of the present invention, showing the state in which the first section and base portion 4a of the self-supporting column 4 and the bracket 5a for the beam member 5 attached to the existing main column 2 are installed, where (a) is a front view and (b) is a cross-sectional view taken from (a) along line (i). [Figure 3] This figure shows the state after the attachment of the second section of the self-supporting column 4 and the attachment of the beam member 5 to the existing main column 2 have been completed. [Figure 4] This diagram shows a state in which a hydraulic jack 7 is installed between the lower end of the beam member 5 and the upper surface of the column base 4a of the self-supporting column 4, where (a) is a front view, (b) is a cross-sectional view of (a) from C to C, and (c) is a cross-sectional view of (b) from H to H. [Figure 5] This figure shows the state in which the piston rod 7a of the hydraulic jack 7 is extended, and the existing main column 2, after being cut, is lifted. [Figure 6] This figure shows the state after the tip of the beam member 5 is temporarily fixed to the self-supporting column 4, the piston rod 7a is pulled back and the hydraulic jack 7 rises, and the lower end of the hydraulic jack 7 is connected to the jack receiving member 9. [Figure 7] This figure shows the state where the piston rod 7a of the hydraulic jack 7 is extended again, and the existing main column 2 is lifted further. [Figure 8]This figure shows the state in which the tip of the beam member 5 of the existing main column 2, which has been lifted again, is temporarily fixed to the self-supporting column 4 again, the piston rod 7a is pulled back and the hydraulic jack 7 rises, and the lower end of the hydraulic jack 7 is connected to the reinstalled jack receiving member 9. [Figure 9] This figure shows the existing main column 2, which has been raised to the final target height, with the extension member 10 attached. [Figure 10] This figure shows the state after the hydraulic jacks 7 and other temporary materials have been removed and the raising work has been completed. [Figure 11] This is an example of the arrangement direction of hydraulic jacks 7 placed in close proximity to an existing main column 2, where (a) shows the case where only direction A is used, and (b) shows the case where A and B are arranged alternately. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described with reference to Figures 1 to 11. As shown in Figure 1, the column heads of the existing main columns 2, 2, ... are pinned to the roof frame 3, and the column bases 2a, 2a, ... of the existing main columns 2, 2, ... are cantilever columns with fixed column bases. We will consider a case where the current effective height H is raised by an additional h. The procedure for raising the height will be described below for one existing main column 2.

[0030] 1) The first section and base portions 4a, 4a, ... of the four self-supporting columns 4, 4, ... fixed to the column base are arranged in a straight line including the existing main column 2 in a plan view, and are constructed at 90° intervals around the existing main column 2, as shown by the line I-I in the cross section of Figure 2(b). The strong axis direction of the cross section of the self-supporting columns 4, 4, ... is inclined at 45° with respect to the beam (and girder) direction of the existing structure 1. The base portions 4a, 4a, ... of the self-supporting columns 4, 4, ... are integrated with the base portion 2a of the existing main column 2, also serving to reinforce it (Figure 2). Although not shown in the diagram, the foundations of the self-supporting columns 4, 4, ... may be constructed integrally with the foundation of the existing main column 2, also serving to reinforce it.

[0031] 2) At the middle position of the existing main column 2, above the point where the existing main column 2 is cut, brackets 5a, 5a, ... for the new beam members 5, 5, ... are rigidly connected in a configuration opposite to the self-supporting columns 4, 4, ... (Figure 2). The second section of each self-supporting column 4, 4, ... is rigidly connected to the first section, and the beam members 5, 5, ... are rigidly connected to the brackets 5a, 5a, .... In addition, adjacent self-supporting columns 4, 4, ... are connected to each other by stiffening members 6, 6, ... which suppress the deformation of the self-supporting columns 4, 4, ... (Figure 3). Note that the stiffening members 6, 6, ... are omitted from the illustration in Figures 4 to 9 below.

[0032] A gap is maintained between the sides of the self-supporting columns 4, 4, ... and the tip surfaces of the beam members 5, 5, ... to prevent contact. When the existing main column 2 is rising, contact between the sides of the self-supporting columns 4, 4, ... and the tip surfaces of the beam members 5, 5, ... will generate frictional resistance, so it is desirable to provide friction-reducing material (not shown) in these gaps to reduce frictional resistance (Figure 3).

[0033] 3) As shown in Figure 4, two hydraulic jacks 7, 7 are positioned vertically and point-symmetrically in a plan view with respect to the existing main column 2, between the lower ends of the beam members 5, 5 and the upper surfaces of the column bases 4a, 4a, ... of the self-supporting columns 4, 4 directly below them. In Figure 4, there are two hydraulic jacks 7, but four may be provided by adding two more directly below the lower ends of the beam members 5, 5 (Figure 4).

[0034] The hydraulic jacks 7, 7 apply an upward force equivalent to the vertical load (axial force) acting on the existing main column 2. The hydraulic jacks 7, 7 have piston rods 7a, 7a facing upward, and their upper ends are connected to rotation-restricting members 8, 8 attached to the lower ends near the tips of the beam members 5, 5 corresponding to the hydraulic jacks 7, 7 (Figure 4(a)).

[0035] The rotation-suppressing members 8 are attached to all beam members 5 and increase the vertical dimension at the tip of each beam member 5. When the existing main column 2 rises, it comes into contact with the sides of the self-supporting columns 4, 4, ..., thereby preventing further tilting of the existing main column 2. This significantly reduces the tilt compared to when the rotation-suppressing members 8, 8, ... are not present.

[0036] Furthermore, as shown in Figure 4(a), if rotation suppression members 8, 8 are attached to the lower ends near the tips of the beam members 5, 5 to which the hydraulic jacks 7, 7 are connected, it is not strictly necessary because the tilt of the existing main column 2 can be adjusted by the hydraulic jacks 7, 7. However, it can be said that having rotation suppression members 8, 8 makes it easier to control the existing main column 2 while it is rising.

[0037] However, for the beam members 5, 5 to which the hydraulic jacks 7, 7 are not connected, it is desirable to attach rotation suppression members 8, 8 with a greater vertical dimension, as shown in Figure 4(c), to suppress the tilt of the existing main column 2 and improve stability.

[0038] 4) With the beam members 5, 5 supported by the hydraulic jacks 7, 7, the existing main column 2 is cut at an appropriate position below the beam members 5, 5, ... 5) The piston rods 7a, 7a are extended by a certain distance, and all of the existing main columns 2 are lifted simultaneously. At this time, the self-supporting columns 4, 4, ... act as guide rails (Figure 5).

[0039] Furthermore, as shown in Figure 5, even if rotation occurs around the axis of the existing main column 2 while it is being raised in a suspended state, the tip surfaces of the beam members 5, 5 to which the hydraulic jacks 7, 7 are connected are prevented from rotating horizontally by the anti-rotation members 5b, 5b attached in the longitudinal direction of the self-supporting members 4, 4. Since the horizontal rotation can be prevented by the two anti-rotation members 5b, 5b, there is no problem even if the anti-rotation members 5b, 5b are not installed on the beam members 5, 5 to which the hydraulic jacks 7, 7 are not connected.

[0040] Incidentally, the form of the anti-rotation members 5b, 5b is not limited to the above, and they may also be attached near the ends of the beam members 5, 5. Note that the rotation-preventing members 5b, 5b are not shown in Figures 6 to 9 below.

[0041] 6) At a predetermined height where the existing main column 2 has been lifted, the beam members 5, 5, ... are temporarily fixed to the sides of the self-supporting columns 4, 4, ... with bolts (Figure 5).

[0042] 7) Since the hydraulic jacks 7, 7 can hang from the temporarily fixed beam members 5, 5, the lower ends of the hydraulic jacks 7, 7 are separated from the upper surfaces of the column bases 4a, 4a of the self-supporting columns 4, 4, and the piston rods 7a, 7a are retracted and raised with their tips connected to the lower ends of the beam members 5, 5 (Figure 6).

[0043] 8) Jack receiving members 9, 9 are installed on the sides of the self-supporting columns 4, 4 at the lower end positions of the hydraulic jacks 7, 7 once they have finished rising, and the lower ends of the hydraulic jacks 7, 7 are connected to and supported (Figure 6).

[0044] 9) Next, the temporary fixing of the beam members 5, 5, ... is released, the piston rods 7a, 7a of the hydraulic jacks 7, 7 are extended, and using the self-supporting columns 4, 4, ... as guide rails, all of the existing main columns 2 of the existing structure 1 are simultaneously lifted to a predetermined height, and at the predetermined height position, the beam members 5, 5, ... are temporarily fixed again to the sides of the self-supporting columns 4, 4, ... (Figure 7).

[0045] 10) Next, the hydraulic jacks 7, 7 are retracted and raised with their lower ends separated from the jack receiving members 9, 9 and their piston rods 7a, 7a tips connected to the lower ends of the beam members 5, 5 (Figure 8).

[0046] 11) Steps 8) to 10) are repeated until the final target height (=H+h) is reached (Figures 6 to 8). If the height of the self-supporting columns 4, 4, ... is insufficient, members of the required length are added to the top of the self-supporting columns 4, 4, ... as shown in Figures 9 and 10.

[0047] 12) When the final target height is reached, the vertical load from the existing main columns 2, which was transmitted to the self-supporting columns 4, 4, ... via beam members 5, 5, ... is transferred to the self-supporting columns 4, 4 via the hydraulic jacks 7, 7 after the lower ends of the hydraulic jacks 7, 7 are connected to the jack receiving members 9, 9 installed on the sides of the self-supporting columns 4, 4, and the temporary fixing of the beam members 5, 5, ... is released (Figure 9).

[0048] 13) Once the final target height is reached and the column is supported by hydraulic jacks 7, 7, the existing main column 2 is lifted and the extension member 10 is inserted into the lifted section, rigidly connecting it to the existing main column 2 and integrating them. At the same time, all the beam members 5, 5, ... are permanently connected to the opposing self-supporting columns 4, 4, ... and further, stiffening members 6, 6, ... such as braces are attached, and the existing main column 2 with the extension member 10 added and the self-supporting columns 4, 4, ... are integrated into a single framework (Figures 9-10).

[0049] The above describes embodiments of the push-up construction method and push-up device according to the present invention. Finally, after step 13), temporary materials such as the hydraulic jacks 7, 7, rotation suppression members and jack support members 9, 9 are removed.

[0050] Furthermore, if four self-supporting columns 4, 4, ... are erected for each existing main column 2, 2, ..., and hydraulic jacks 7, 7, ... are arranged in a single row of two in the direction of arrow A, as shown in Figure 11(a), then the existing main columns 2, 2, ... after cutting can be kept vertical without tilting by finely adjusting the extension and retraction of the piston rods 7a, 7a of the two hydraulic jacks 7, 7 in the direction of arrow A, thereby preventing tilting in the direction of arrow A. However, since there are no hydraulic jacks 7, 7 in the direction of arrow B, that operation cannot be performed.

[0051] In the above embodiment, rotation-suppressing members 8,8,... are attached to the lower ends near the tips of the beam members 5,5,... even in the direction of arrow B where there are no hydraulic jacks 7,7, so it is thought that no large inclination will occur. However, since there is a small gap between the sides of the self-supporting columns 4,4,... and the tip surfaces of the beam members 5,5,..., the existing main columns 2,2,... may tilt slightly, at least during the ascent.

[0052] If all existing main columns 2, 2, ... were to tilt uniformly in the direction of arrow B, the roof frame 3 would move horizontally as shown by the dashed line in Figure 11(a), which is undesirable for ensuring accuracy after completion.

[0053] Therefore, instead of arranging the hydraulic jacks 7, 7 in the same direction, if they are arranged alternately in the direction of arrow A and arrow B, as shown in Figure 11(b), for example, fine adjustment of the extension and retraction amount of the two piston rods 7a, 7a in each direction becomes possible, making it easier to maintain the verticality of the existing main columns 2, 2, ...

[0054] Alternatively, to resolve the above problem, it is conceivable to install four hydraulic jacks 7, 7 in both the direction of arrow A and arrow B, doubling the number to four. However, this would also double the cost. Therefore, to ensure a balanced and appropriate arrangement, it may be better to limit the number of hydraulic jacks 7 to four only on some of the existing main pillars 2, 2, ... [Industrial applicability]

[0055] The present invention provides a push-up method and apparatus that allows existing main columns, which have been cut and are suspended in mid-air, to be stably held and safely lifted when raising an existing structure. This greatly contributes to improved workability and safety during construction, as well as to the technological development of the field of modification work for existing structures. [Explanation of symbols]

[0056] 1: Existing structures 2: Existing main pillars 2a: Base of existing main column 3: Roof frame 4: Freestanding pillar 4a: Base of a self-supporting column 5: Beam members 5a: Bracket 5b: Anti-rotation material 6: Stiffening member 7: Hydraulic jack 7a: Piston rod 8: Rotation suppression member 9: Jack support member 10: Extension parts

Claims

1. When raising an existing structure in which the top of the existing main column is pinned to the roof frame and the base of the column is supported by a cantilevered column with a fixed base, 1) Self-supporting columns fixed to their bases are arranged in close proximity to the existing main columns of the existing structure, as pairs of columns in a straight line including the existing main columns in a plan view, and at least two pairs of such columns are arranged at predetermined intervals so as to intersect each other. 2) Above the point where the existing main column is cut, beam members of a predetermined length are attached to the side of the existing main column in at least four directions so as to face the self-supporting column, and a gap is ensured between the side of the self-supporting column and the tip surface of the beam members so as not to come into contact. 3) At least one pair of hydraulic jacks are vertically installed between the lower end of the beam member and directly below it, between the upper surface of the base of the column of the self-supporting column, as a pair of jacks in a straight line including the existing main column in a plan view, and the hydraulic jacks apply an upward force equivalent to the vertical load (axial force) acting on the existing main column. 4) While supported by the hydraulic jack, the existing main column is cut at an appropriate position at its lower part. 5) After the existing main columns are cut, the piston rod of the hydraulic jack is extended, and the existing main columns are all simultaneously lifted to a predetermined height, using the self-supporting columns as guide rails. 6) At a predetermined height position where the existing main column has been lifted, the beam member is temporarily fixed to the side of the self-supporting column. 7) The hydraulic jack is raised when its lower end is separated from the upper surface of the column base of the self-supporting column and the tip of the piston rod is connected to the lower end of the beam member, and the piston rod is retracted. 8) A jack receiving member is installed on the side of the self-supporting column at the lower end position of the hydraulic jack once it has finished rising, and the lower end of the hydraulic jack is connected to it. 9) Next, the temporary fixing of the beam member is released, the piston rod is extended again, and using the self-supporting column as a guide rail, all of the existing main columns of the existing structure are simultaneously raised to a predetermined height, and at the predetermined height position, the beam member is temporarily fixed again to the side of the self-supporting column. 10) Next, the hydraulic jack is raised as the piston rod is retracted, with its lower end separated from the jack receiving member and the tip of the piston rod connected to the lower end of the beam member. 11) The steps in 8) to 10) above are repeated until the final target height is reached. 12) After reaching the final target height, the vertical load from the existing main column is transferred to the self-supporting column via the hydraulic jack after the lower end of the hydraulic jack is connected to the jack receiving member which has been reinstalled on the side of the self-supporting column, and the temporary fixing of the beam member is released. 13) After the vertical load from the existing main column is transferred to the self-supporting column, the existing main column is lifted and the extension member is inserted into the lifted section secured, rigidly joining it with the existing main column to form a unified structure. At the same time, all the beam members are permanently joined to the opposing self-supporting columns, and the existing main column to which the extension member has been added and the self-supporting column are integrated as a framework. A push-up method for structures, characterized by including the above steps.

2. A push-up construction method for a structure according to claim 1, characterized in that the direction in which pairs of hydraulic jacks are arranged in a straight line including the existing main column in a plan view, surrounding and in close proximity to the existing main column, is not the same for all of the existing main columns.

3. A device used in the push-up method for a structure according to claim 1, 1) In close proximity to the existing main column of the existing structure, self-supporting columns fixed to their bases are arranged at predetermined intervals so that at least two sets of such columns intersect, forming pairs of columns on a straight line including the existing main column in a plan view. 2) Above the position where the existing main column is cut, beam members of a predetermined length are rigidly joined to the side surface of the existing main column in at least four directions so as to face the self-supporting column, and a gap is ensured between the side surface of the self-supporting column and the tip surface of the beam members so as not to come into contact, and a rotation-preventing member is installed to prevent horizontal rotation of the tip surface of the beam members due to the rotation of the existing main column around its axis. 3) At least one pair of hydraulic jacks are vertically installed between the lower end of the beam member and directly below it, between the upper surface of the base of the self-supporting column, as a pair of jacks in a straight line including the existing main column in a plan view. 4) The hydraulic jack having a piston rod is mounted with its lower end on the upper surface of the column base of the self-supporting column or on a jack receiving member installed on the side of the self-supporting column, and the tip of the piston rod is connected to the lower end of the beam member. 5) The hydraulic jack has the capacity necessary to extend the piston rod and simultaneously lift all of the existing main columns of the existing structure when the existing main columns have been cut. A push-up device for use in a push-up construction method for structures, characterized by including the above configuration.

4. A push-up device for use in a push-up construction method for structures, characterized in that a rotation suppression member is attached to the lower end or upper end near the tip of the beam member attached to the existing main column, in the push-up device according to claim 3.

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