A method of unloading construction

Abstract

The present application relates to a kind of unloading construction methods, construction in the bottom of box girder, the bottom of the box girder is provided with several steel pipe piles, the top of the steel pipe pile is provided with load-bearing beam, the top of the load-bearing beam is provided with the support column of supporting the box girder, the construction method includes the following steps: selecting the steel pipe pile to be unloaded, cutting off the support column of the top of the steel pipe pile to be unloaded;Lifting the load-bearing beam;Cut off part of the steel pipe pile to be unloaded, and weld steel plate on the top of the cut-off steel pipe pile;Lower the load-bearing beam, so that the load-bearing beam is set on the top of the steel plate, weld the load-bearing beam and the steel plate;Load sand box is constructed on the top of the load-bearing beam, and fixed column is arranged between the load sand box and the box girder;Repeat the above steps until several steel pipe piles are constructed, simple operation, and wide application range.

Description

Technical Field

[0001] This invention relates to the field of construction engineering, and specifically to a method for unloading construction. Background Technology

[0002] With the development of modern cities, the demand for landscape enhancement is increasing, and bridge designs are becoming more diversified. Because steel structures typically have smaller bending moments under vertical loads than continuous beams or simply supported beams of the same span, their spanning capacity is greater than that of beam bridges, leading to their growing popularity. Steel structure bridges are usually manufactured in factories and assembled on-site.

[0003] Temporary supports need to be added in the middle of long-span steel beams. In water-crossing sections, temporary steel pipe supports are usually used in the water. To ensure construction safety and support stability, a combination of steel pipe piles, scissor bracing, load-bearing beams, and support columns is used. The length of the support columns is usually not too long to prevent the support columns from tilting and deforming due to temperature deformation of the steel beams. This makes it difficult to unload the supports when the pre-camber of some steel structure bridges is large (even if all the support columns are cut off, the pre-camber release height will not be met).

[0004] Meanwhile, steel structure bridges have a longer construction period (which may span summer and winter, as well as seasonal flood season) and lower stiffness. In contrast, cast-in-place beams have a shorter construction period and higher stiffness. Therefore, unloading sand boxes cannot be installed on the support frame in advance to prevent displacement. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an unloading construction method that cuts off a portion of the steel pipe pile to meet the pre-arch release height.

[0006] The technical solution to achieve the above objective is an unloading construction method, which is constructed at the bottom of a box girder. Several steel pipe piles are installed below the box girder, a load-bearing beam is installed on top of the steel pipe piles, and a support column supporting the box girder is installed on top of the load-bearing beam. The construction method includes the following steps:

[0007] Select the steel pipe pile to be unloaded and cut off the support column at the top of the steel pipe pile to be unloaded;

[0008] Raise the load-bearing beam;

[0009] Part of the steel pipe pile to be unloaded is cut off, and a steel plate is welded to the top of the cut steel pipe pile;

[0010] Lower the load-bearing beam so that it is positioned on top of the steel plate, and weld the load-bearing beam and the steel plate together.

[0011] A load-bearing sand box is constructed on top of the load-bearing beam, and a fixing column is installed between the load-bearing sand box and the box beam;

[0012] Repeat the above steps until all of the steel pipe piles have been constructed.

[0013] Furthermore, several of the steel pipe piles are arranged opposite each other, and a distribution beam is provided between two oppositely arranged steel pipe piles. The distribution beam is located between the load-bearing beam and the steel pipe pile.

[0014] Before removing the support column, cut the distribution beam located between the steel pipe pile to be unloaded and another steel pipe pile;

[0015] After the load-bearing beam is lifted, the cut-off distribution beam is removed from the top of the steel pipe pile to be unloaded.

[0016] Furthermore, before removing the support column, the support columns at the top of the remaining steel pipe piles are reinforced.

[0017] Furthermore, after the steel pipe pile is cut off, stiffening ribs are welded to the side of the cut-off steel pipe pile.

[0018] Furthermore, the load-bearing beam can be raised or lowered using a hand-operated hoist.

[0019] Furthermore, after the support columns are removed, the elevation changes of the box girder are monitored throughout the process.

[0020] Furthermore, the length of the fixed column is adapted to the distance between the load sand box and the box girder.

[0021] Furthermore, the cutting thickness of the steel pipe pile is determined based on the actual construction conditions on site.

[0022] Furthermore, the load-bearing sand box is positioned at the center of the load-bearing beam.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The remaining support columns are reinforced first to prevent danger during use, and the excess parts of the steel pipe piles are cut off to meet the pre-arch release height. Attached Figure Description

[0025] Figure 1 This is an overall structural diagram of an unloading construction method according to the present invention.

[0026] Figure 2 This is a rendering of the cutting and distribution beam in an unloading construction method according to the present invention.

[0027] Figure 3 This is a diagram illustrating the effect of cutting off a support column in an unloading construction method according to the present invention.

[0028] Figure 4This is a diagram illustrating the effect of cutting off the distribution beam in an unloading construction method according to the present invention.

[0029] Figure 5 This is a diagram illustrating the effect of cutting steel pipe piles using an unloading construction method according to the present invention.

[0030] Figure 6 This is a rendering of the effect of lowering a load-bearing beam according to the unloading construction method of the present invention.

[0031] Figure 7 This is a diagram illustrating the effect of a load sand box construction method according to the present invention.

[0032] Figure 8 This is a construction completion diagram of an unloading construction method according to the present invention.

[0033] Legend: 1. Box girder; 2. Steel pipe pile; 3. Load-bearing beam; 4. Support column; 5. Distribution beam; 6. Working platform; 7. Load sand box; 8. Fixed column. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] See Figure 1 , Figure 3 , Figure 5 , Figure 6 , Figure 7 and Figure 8 A method for unloading construction is described, involving construction at the bottom of a box girder 1. Several steel pipe piles 2 are installed below the box girder 1, and a load-bearing beam 3 is installed on top of each steel pipe pile 2. A support column 4 supporting the box girder 1 is installed on top of the load-bearing beam 3. The construction method includes the following steps: selecting the steel pipe piles 2 to be unloaded; cutting off the support column 4 on top of the steel pipe piles 2 to be unloaded; raising the load-bearing beam 3; cutting off a portion of the steel pipe piles 2 to be unloaded, and welding a steel plate to the top of the cut steel pipe piles 2; lowering the load-bearing beam 3 so that it is positioned on top of the steel plate, and welding the load-bearing beam 3 and the steel plate together; constructing a load sand box 7 on top of the load-bearing beam 3, and installing a fixing column 8 between the load sand box 7 and the box girder 1; repeating the above steps until all the steel pipe piles 2 are constructed.

[0036] In a preferred embodiment of this invention, a working platform 6 is provided on two adjacent steel pipe piles 2. The height of the working platform 6 is lower than the height of the steel pipe pile 2 after it has been cut. Through the working platform 6, construction personnel can conveniently carry out construction on the steel pipe piles 2. To ensure safety during construction, shear bracing is provided at the bottom of the working platform 6. The shear bracing improves the load-bearing capacity of the working platform 6, thereby significantly increasing the safety of the operation. To ensure the strength of the support, the support column 4 is supported by short steel pipes, the specific length of which is determined by on-site measurements. The support column 4 and the load-bearing beam 3 are fixed by welding. To ensure the support effect, multiple support columns 4 are provided. After the overall structure is erected, one of the steel pipe piles 2 is selected, and the pile located above it is... The supporting column 4 is cut off. During the cutting, an intermittent cutting method should be used to avoid the box girder 1 tilting due to stress concentration after cutting. Then, the load-bearing beam 3 is raised and the steel pipe pile 2 located below is cut off. The thickness of the cut is determined according to the actual needs of the site. Then, the load-bearing beam 3 is lowered. When raising and lowering the load-bearing beam 3 and cutting off the steel pipe pile 2, care should be taken to avoid collisions with the steel pipe pile 2, which could damage the steel pipe pile 2 and lead to rework. When fixing the load-bearing beam 3 and the steel plate, ensure that the bottom of the load-bearing beam 3 is flush to avoid stress concentration during subsequent construction. An unloading sand box is set on the top of the load-bearing beam 3. The sand inside the unloading sand box needs to be compacted precisely, and the outside is firmly connected to the load-bearing beam 3 to prevent deformation, tilting and displacement due to temperature changes of the box girder 1.

[0037] See Figure 2 and Figure 4 Furthermore, several steel pipe piles 2 are arranged opposite each other, and a distribution beam 5 is provided between two oppositely arranged steel pipe piles 2. The distribution beam 5 is located between the load-bearing beam 3 and the steel pipe pile 2. Before cutting off the support column 4, the distribution beam 5 located between the steel pipe pile 2 to be unloaded and another steel pipe pile 2 is cut off. After lifting the load-bearing beam 3, the cut distribution beam 5 is cut off at the top of the steel pipe pile 2 to be unloaded. Preferably, during on-site construction, 140a I-beams are used as distribution beams 5. When disconnecting the distribution beam 5, it is usually separated at the center position of the distribution beam 5, that is, separated in the middle of the two oppositely arranged steel pipe piles 2, so as to avoid the difficulty of subsequent demolition due to excessive stress on one side.

[0038] Furthermore, before removing the support column 4, the support columns 4 at the top of the remaining steel pipe piles 2 are reinforced. This reinforcement of the support columns 4 prevents the box girder 1 located above from deflecting.

[0039] Furthermore, after the steel pipe pile 2 is cut off, stiffening ribs are welded to the side of the cut steel pipe pile 2. The top elevation of the stiffening ribs is level with the top elevation of the cut steel pipe pile 2.

[0040] Furthermore, the load-bearing beam 3 is raised or lowered using hand-operated hoists. Four sets of 20t hand-operated hoists are used simultaneously to raise or lower the 2H500×200 load-bearing beam 3.

[0041] Furthermore, after the support column 4 is removed, the elevation change of the box girder 1 is monitored throughout the process.

[0042] Furthermore, the length of the fixed column 8 is adapted to the distance between the load sand box 7 and the box beam 1.

[0043] Furthermore, the cutting thickness of the steel pipe pile 2 is determined based on the actual construction conditions on site.

[0044] Furthermore, the load sand box 7 is located at the center of the load-bearing beam 3.

[0045] The following describes the process of using the unloading construction method of the present invention.

[0046] A working platform 6 is set on two adjacent steel pipe piles 2. The height of the working platform 6 is lower than the height of the steel pipe pile 2 after it has been cut. Through the working platform 6, construction workers can easily carry out construction on the steel pipe pile 2 and cut the distribution beam 5. To ensure safety during construction, shear bracing is installed at the bottom of the working platform 6. The shear bracing can improve the load-bearing capacity of the working platform 6, thereby greatly increasing the safety of the operation. To ensure the strength of the support, the support column 4 is supported by short steel pipes. The specific length is based on the actual measurement value on site. The support column 4 and the load-bearing beam 3 are fixed by welding. To ensure the support effect, multiple support columns 4 are set. After the overall structure is erected, one of the steel pipe piles 2 is selected, and the upper part of the support column 4 is then installed on top of the steel pipe pile 2. The supporting column 4 is cut off. During the cutting, an intermittent cutting method should be used to avoid the box girder 1 tilting due to stress concentration after cutting. Then, the load-bearing beam 3 is raised and the steel pipe pile 2 located below is cut off. The thickness of the cut is determined according to the actual needs of the site. Then, the load-bearing beam 3 is lowered. When raising and lowering the load-bearing beam 3 and cutting off the steel pipe pile 2, care should be taken to avoid collisions with the steel pipe pile 2, which could damage the steel pipe pile 2 and lead to rework. When fixing the load-bearing beam 3 and the steel plate, ensure that the bottom of the load-bearing beam 3 is flush to avoid stress concentration during subsequent construction. An unloading sand box is set on the top of the load-bearing beam 3. The sand inside the unloading sand box must be compacted precisely, and the outside must be firmly connected to the load-bearing beam 3 to prevent deformation, tilting, and displacement due to temperature changes in the box girder 1.

[0047] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for unloading construction, the bottom of the box girder is provided with a plurality of steel pipe piles, the top of the steel pipe pile is provided with a bearing beam, the top of the bearing beam is provided with a support column supporting the box girder, characterized in that, The construction method comprises the following steps: The steel pipe piles are oppositely arranged, and a distribution beam is arranged between two oppositely arranged steel pipe piles, and the distribution beam is located between the load-bearing beam and the steel pipe pile; the steel pipe pile to be unloaded is selected, the support column at the top of the remaining steel pipe piles is reinforced, the distribution beam between the steel pipe pile to be unloaded and another steel pipe pile is cut off, and the support column at the top of the steel pipe pile to be unloaded is cut off; The load-bearing beam is lifted, and then the cut-off distribution beam at the top of the steel pipe pile to be unloaded is cut off; Part of the steel pipe pile to be unloaded is cut off, and a steel plate is welded at the top of the cut-off steel pipe pile; The load-bearing beam is lowered, so that the load-bearing beam is arranged at the top of the steel plate, and the load-bearing beam and the steel plate are welded and fixed; A load sand box is constructed at the top of the load-bearing beam, and a fixing column is arranged between the load sand box and the box girder; The above steps are repeated until the construction of the steel pipe piles is completed.

2. The method of claim 1, wherein: After the steel pipe pile is cut off, a stiffening rib is welded at the side of the cut-off steel pipe pile.

3. The method of claim 1, wherein: The load-bearing beam is lifted or lowered by a hand-operated hoist.

4. The method of claim 1, wherein: After the support column is cut off, the change of the elevation of the box girder is monitored.

5. The method of claim 1, wherein: The length of the fixing column is matched with the distance between the load sand box and the box girder.

6. The method of claim 1, wherein: The cutting thickness of the steel pipe pile is determined according to the actual construction condition on site.

7. The method of claim 1, wherein: the method further comprises: determining a load on the one or more actuators; and adjusting the one or more actuators to reduce the load on the one or more actuators. The load sand box is arranged at the center of the load-bearing beam.

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