A method for dismantling post-tensioned bonded prestressed beams

Abstract

The present invention relates to a method for dismantling a post-tensioned bonded prestressed beam, comprising a post-tensioned bonded prestressed beam, a frame column, a beam prestressed steel strand, a support frame, and a temporary support. The post-tensioned bonded prestressed beam needs to be dismantled due to the adjustment of the building function. Direct dismantling will endanger the safety of construction workers and may cause damage to the structure itself. The method utilizes the principle of mechanics, and cuts the post-tensioned bonded prestressed beam symmetrically and in sections from the mid-span to both sides. The beam prestressed steel strand is retained during the cutting process. After the segmented cutting is completed, the beam is continued to be cut symmetrically and in sections from the mid-span to both sides until the beam is completely cut off. In the process of the segmented cutting of the post-tensioned bonded prestressed beam, the stress is gradually released, leaving time for the structural system to adjust the stress. After the stress of the structural system is adjusted in place, the post-tensioned bonded prestressed beam is completely cut off. The method is safe, reliable, and highly practical.

Description

Technical Field

[0001] The invention relates to the field of building structures, in particular to building structure reconstruction, and is a method for dismantling post-tensioned bonded prestressed beams. Background Art

[0002] Most of the large-span prestressed beams in the field of building structures are post-tensioned bonded prestressed beams. Due to the adjustment of building functions, changes in building space sometimes involve the removal of large-span prestressed beams of the original structure. The prestressed beams have large cross-sections and self-weight, and the tension of the prestressed tendons in the beams is large. Rash removal will cause the contraction of the prestressed tendons in the beams, and the stress adjustment of the columns connected to the beams will endanger the safety of the construction workers and may cause damage to the structure itself. The traditional removal method is usually to remove the anchor nodes at the ends of the prestressed tendons first, and then remove the prestressed beams after the stress of the prestressed tendons is released. Since the anchor nodes are often enclosed in the frame columns or frame beams, the removal process is very troublesome. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects and to provide a method for dismantling a post-tensioned bonded prestressed beam.

[0004] In order to achieve the above object, the present invention is implemented by the following technical scheme: a method for dismantling a post-tensioned bonded prestressed beam, comprising the following steps:

[0005] 1) The post-tensioned bonded prestressed beam is supported by the support frame and temporary support;

[0006] 2) Cutting the post-tensioned bonded prestressed beam from top to bottom with a cutting machine in the middle of the span of the post-tensioned bonded prestressed beam, and stopping when approaching the prestressed tendons of the post-tensioned bonded prestressed beam, to form a non-through cutting seam in the middle of the span;

[0007] 3) Cut the post-tensioned bonded prestressed beams in sections from the mid-span to both sides of the post-tensioned bonded prestressed beams, and stop when all cuts are close to the prestressed tendons of the post-tensioned bonded prestressed beams, forming multiple non-penetrating cut seams on the span sides. Structural monitoring should be done well during the construction process. If the column deformation is too large or the main structure vibrates greatly, the demolition should be stopped to find the cause;

[0008] 4) Continue cutting downward along the non-penetrating cutting seam in the mid-span until the post-tensioned bonded prestressed beam is completely cut off;

[0009] 5) Continue cutting downward along multiple non-penetrating cutting seams along the span until the post-tensioned bonded prestressed beam is completely cut off;

[0010] 6) Transport the cut post-tensioned bonded prestressed beams away and remove the supporting frame and temporary supports.

[0011] The prestressed tendons of the post-tensioned bonded prestressed beam are prestressed steel strands.

[0012] The step 3) is segmented cutting from the mid-span of the post-tensioned bonded prestressed beam to both sides. The segmented cutting in the post-tensioned bonded prestressed beam is symmetrical segmented cutting with the mid-span of the post-tensioned bonded prestressed beam as the symmetry line.

[0013] The multiple non-penetrating cut seams on the side of the span are symmetrically distributed along a symmetry line in the middle of the span of the post-tensioned bonded prestressed beam.

[0014] The present invention uses a cutting machine to cut the post-tensioned bonded prestressed beam from top to bottom in the mid-span of the post-tensioned bonded prestressed beam, forming a non-through cut seam in the mid-span; and gradually cuts in sections to gradually release the stress, leaving time for the structural system to adjust the stress. After the stress of the structural system is adjusted to the right point, the post-tensioned bonded prestressed beam is completely cut off, which is safe, reliable and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Side view of post-tensioned bonded prestressed beam.

[0016] Figure 2 for Figure 1 Side view of a post-tensioned bonded prestressed beam after partial cutaway under temporary support.

[0017] Figure 3 for Figure 2 Sectional view of post-tensioned bonded prestressed beam 1-1 (section at the cutting seam after partial cutting). Implementation

[0018] The present invention is further described below through specific embodiments. The drawings are only used for exemplary descriptions, and are only schematic diagrams, not physical drawings, and cannot be understood as limitations on this patent; in order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0019] The present invention comprises: a post-tensioned bonded prestressed beam 1, a frame column 2, a beam prestressed steel strand 3, a support frame 4, a temporary support 5, and a cutting seam 6.

[0020] Examples, such as Figure 1-3 Due to the need for building adjustment, the large-span post-tensioned bonded prestressed beams 1 between the frame columns 2 need to be removed. According to the patent of the present invention, the removal is safe and reliable, meeting the requirements of building adjustment.

[0021] An embodiment of a method for dismantling a post-tensioned bonded prestressed beam according to the present invention comprises the following steps:

[0022] (1) The post-tensioned bonded prestressed beam 1 is supported by the support frame 4 and the temporary support 5.

[0023] (2) A cutting machine is used to cut the bonded prestressed beam 1 from top to bottom in the mid-span, and the cutting machine stops when it approaches the prestressed tendons 3, forming a non-through cutting seam 6 in the mid-span.

[0024] (3) Cut the bonded prestressed beam 1 symmetrically from the mid-span to both sides, and stop when all cuts are close to the prestressed steel strands 3, forming multiple cutting seams 6. The structure should be monitored during the construction process. If the column deformation is too large or the main structure vibrates greatly, the demolition should be stopped to find the cause.

[0025] (4) Continue cutting downward along the mid-span cutting seam 6 until the beam is completely cut off.

[0026] (5) Continue cutting symmetrically and in sections from the mid-span to both sides along the cutting seam 6 until the beam is completely cut off.

[0027] (6) The segmented prestressed beam 1 is transported away, and the support frame 4 and temporary support 5 are dismantled.

[0028] During the construction process of the present invention, the building structure connected by the post-tensioned bonded prestressed beams is monitored.

[0029] The prestressed tendons are prestressed steel strands.

[0030] The segmented cutting from the mid-span of the post-tensioned bonded prestressed beam to both sides is a symmetrical segmented cutting with the mid-span of the post-tensioned bonded prestressed beam as the symmetry line.

[0031] The multiple non-penetrating cut seams on the side of the span are symmetrically distributed along the symmetry line in the middle of the span of the post-tensioned bonded prestressed beam.

[0032] In the process of segmented and step-by-step cutting, the present invention gradually releases stress, leaving time for the structural system to adjust the stress. After the stress of the structural system is adjusted to the right position, the post-tensioned bonded prestressed beam is completely cut off, which is safe, reliable and highly practical.

[0033] The embodiments are only for the purpose of explaining the outstanding features of the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above descriptions, and if no creative improvements are made, they all fall within the scope of protection of the present invention.

Claims

1. A method for dismantling a post-tensioned bonded prestressed beam, characterized in that: The following steps are involved: 1) Supporting the post-tensioned bonded prestressed beam by means of a support frame and temporary supports; 2) Cutting the post-tensioned bonded prestressed beam from top to bottom with a cutting machine in the middle of the span of the post-tensioned bonded prestressed beam, and stopping when approaching the prestressed tendons of the post-tensioned bonded prestressed beam, to form a non-through cutting seam in the middle of the span; 3) Cut the post-tensioned bonded prestressed beam in sections from the mid-span of the post-tensioned bonded prestressed beam to both sides, and stop when all the cutting is close to the prestressed tendons of the post-tensioned bonded prestressed beam, so as to form a plurality of non-penetrating cutting seams on the side of the span; the plurality of non-penetrating cutting seams on the side of the span of the post-tensioned bonded prestressed beam are symmetrically distributed with the mid-span of the post-tensioned bonded prestressed beam being a symmetry line; 4) Continue cutting downward along the mid-span non-penetrating cutting seam in step 2) until the post-tensioned bonded prestressed beam is completely cut off; 5) Continue cutting downward along the multiple non-penetrating cutting seams along the side of the span in step 3) until the post-tensioned bonded prestressed beam is completely cut off; 6) The cut post-tensioned bonded prestressed beam is transported away, and the support frame and the temporary support are dismantled.

2. The dismantling method according to claim 1, characterized in that: The building structure with post-tensioned bonded prestressed beam connections is monitored during the construction process from step 2) to step 5).

3. The dismantling method according to claim 1, characterized in that: The prestressed tendons are prestressed steel strands.

4. The removal method according to claim 1 or 2, characterized in that: The step 3) is segmented cutting from the mid-span of the post-tensioned bonded prestressed beam to both sides. The segmented cutting in the post-tensioned bonded prestressed beam is symmetrical segmented cutting with the mid-span of the post-tensioned bonded prestressed beam as the symmetry line.

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