Platform special for assembly type staircase for construction site

Abstract

The utility model provides a special assembled staircase platform for a construction site. The special assembled staircase platform comprises a stand column group, a horizontal connecting rod, a hoisting ring, an interlayer protection plate, an up-and-down step ladder, a platform panel and a platform cross brace, each stand column set is provided with two stand columns which are vertically arranged, the horizontal connecting rods comprise three layers, and each layer of horizontal connecting rods are formed by connecting a plurality of horizontally-arranged galvanized square pipes with the stand columns in sequence. The hoisting rings are welded to the four corners of the third layer of horizontal connecting rod. The platform panel is arranged on a second-layer horizontal connecting rod and a platform cross brace which are close to one side of the upright column group C and the upright column group D; and the up-down step ladders are divided into two groups. After floor concrete is poured, one-time hoisting is conducted, integrality is good, safety is high, the size is small, the weight is light, wall contact and attachment are better, operation is easy, construction efficiency can be effectively improved, the safety requirement is met, construction and maintenance cost is reduced, and the requirements for energy saving and material saving are met.

Description

Technical Field

[0001] The utility model relates to a special platform for assembled stairwells on construction sites, in particular to a special platform for assembled stairwells on construction sites which is easy to operate and safe and reliable. Background Art

[0002] When a project uses prefabricated staircases, they only need to be hoisted. Compared to cast-in-place structural stairs, this eliminates the need for a formwork support system, making construction more convenient. However, during construction, prefabricated stairs must be installed after the construction floor, meaning they can only be installed up to floor N-1 (floor N is the construction floor, and floor N-1 is the demolding floor for the cast-in-place structure). In this context, workers will encounter the problem of having no foothold during stairwell construction on floor N. A common method is to erect a steel pipe fastener scaffold on the stairs and lay scaffolding planks as a foothold for workers. This scaffolding also needs to be erected and dismantled floor by floor, which is labor-intensive and time-consuming, easily impacting the progress of structural construction. Furthermore, it is not secure and poses certain safety risks. Currently, there are some stairwell operating platforms on the market. While these can eliminate the need for erection and dismantling, they are generally unstable and unstable. Utility Model Content

[0003] In order to solve the deficiencies in the above technical problems, the technical solution adopted by the present invention is: a special platform for assembled stairwells for construction sites, including a column group, a horizontal connecting rod, a lifting ring, an interlayer protective plate, an upper and lower step ladder, a platform panel, and a platform cross brace; the column group includes a column group A, a column group B, a column group C, and a column group D; each column group has two vertically arranged columns, and the columns are all made of galvanized square tubes, preferably galvanized square tubes with a size of 50mm*50mm, wherein the spacing between the columns in each column group is 700mm, and the lower ends of the two columns in each group are flush;

[0004] The A column group and the B column group are in the same plane, and the A column group is located on the right side of the B column group, and the distance between the A column group and the B column group is 400mm; the C column group is located on the opposite side of the A column group, and the vertical distance between the C column group and the A column group is 1900mm; the D column group is located on the opposite side of the B column group and is in the same plane as the C column group; the horizontal connecting rods include the first layer horizontal connecting rods, the second layer horizontal connecting rods, and the third layer horizontal connecting rods. Each layer of horizontal connecting rods is composed of multiple horizontally placed galvanized square tubes connected to the columns in sequence; hoisting The ring is made of horseshoe-shaped steel bars and is welded to the four corners of the third-layer horizontal connecting rod. The lifting ring is set at a 45° angle to the third-layer horizontal connecting rod; the platform panel is set on the second-layer horizontal connecting rod and the platform cross brace close to the side of the C column group and the D column group; the platform cross brace is placed horizontally and parallel to the plane of the C column group. The two ends of the platform cross brace are vertically welded to the second-layer horizontal connecting rod located between the outer columns of the A column group and the C column group and the B column group and the D column group; the platform cross brace and the second-layer horizontal connecting rod are in the same horizontal plane.

[0005] The utility model comprises two groups of up and down step ladders. The starting position of the first group of up and down step ladders is located at the first horizontal connecting rod between the two columns of the A column group 1, and the ending position is located at the platform cross brace corresponding to the C column group; the starting position of the second group of up and down step ladders is located at the platform cross brace corresponding to the D column group, and the ending position is located at the third horizontal connecting rod between the two columns of the B column group.

[0006] In order to better play the role of reinforcement and protection, the column group of the present invention also includes an E column group; the lower ends of the two columns of the E column group are flush; the two columns of the E column group are respectively opposite to the columns on the inner side of the C column group and the D column group 4, and the vertical distance between the E column group and the C column group 3 is 500mm; the top surface of the E column group is flush with the upper surface of the third-layer horizontal connecting rod, and the bottom surface of the E column group is connected to the upper surface of the platform cross brace. More specifically, the first-layer horizontal connecting rods horizontally connect every two adjacent columns in the A column group to the D column group, and the upper surface of the first-layer horizontal connecting rods is 2700mm away from the bottom surface of the A column group; the second-layer horizontal connecting rods horizontally connect every two adjacent columns in the C column group and the D column group, horizontally connect the two outer columns of the B column group and the D column group, horizontally connect the two outer columns of the A column group and the C column group, horizontally connect the two inner columns of the A column group and the B column group, horizontally connect the columns on the inner side of the A column group and the platform cross brace, and horizontally connect the columns on the inner side of the B column group and the platform cross brace; the second-layer horizontal connecting rods are located directly above the first-layer horizontal connecting rods, and the upper surface of the second-layer horizontal connecting rods is 1450mm away from the upper surface of the first-layer horizontal connecting rods.

[0007] The third-layer horizontal connecting rods horizontally connect every two adjacent columns in the A column group and the B column group, horizontally connect the two middle and outer columns of the A column group and the C column group, horizontally connect the two middle and outer columns of the B column group and the D column group, horizontally connect the two middle and outer columns of the C column group and the D column group, and horizontally connect the corresponding columns in the A column group, the B column group and the E column group respectively; the upper surface of the third-layer horizontal connecting rods is 2850mm away from the upper surface of the first-layer horizontal connecting rods.

[0008] In order to prevent workers from stepping into empty space during construction and to enhance safety protection, the utility model is provided with an interlayer protective plate, which is specifically made of 3mm patterned steel plate. A patterned steel plate with an equal length of 700mm, a height of 50mm and a thickness of 3mm is vertically welded at 0mm and 60mm on the long side of one end of the interlayer protective plate. This makes it easier to place on the first layer of horizontal connecting rods between the A column groups and the third layer of horizontal connecting rods between the B column groups.

[0009] The platform panel is made of 3mm patterned steel plate with a size of 2000mm*600mm. The platform panel is provided with 50mm*50mm square holes at the positions corresponding to the columns of the C column group, D column group and E column group.

[0010] More specifically, the two columns of the A column group of the present invention are both 6660mm long; the two columns of the B column group are of equal length; the lower end of the B column group is welded to the upper surface of the first layer of horizontal connecting rod, and the upper end of the B column group is flush with the upper end of the A column group; the top of the inner column of the B column group is connected to the top of the inner column of the A column group through a cross brace; the top of the outer column of the B column group is connected to the top of the outer column of the D column group through a cross brace; the top of the outer column of the C column group is connected to the top of the outer column of the A column group through a cross brace; the top surface of the inner column is vertically welded to the lower surface of the third horizontal connecting rod; the bottom surface of the C column group is 1150mm higher than the bottom surface of the A column group; the upper end of the outer column of the D column group is flush with the upper end of the B column group; the top surface of the inner column of the D column group is welded to the lower surface of the third layer of horizontal connecting rod, and the bottom surface of the D column group is 1490mm higher than the bottom surface of the A column group.

[0011] The utility model is hoisted once after the floor concrete is poured. It has good integrity, high safety, small size, light weight, better contact and fit with the wall, easy operation, can effectively improve construction efficiency, ensure safety requirements, reduce construction and maintenance costs, and meet the requirements of energy saving and material saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be described in further detail below with reference to the accompanying drawings and specific implementations.

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0014] Figure 2 It is a schematic diagram of the connection structure of the column group and the horizontal connecting rod of the utility model.

[0015] Figure 3 yes Figure 1 Top view of .

[0016] Figure 4 yes Figure 1 Left view of .

[0017] Figure 5 It is a structural diagram of the platform panel.

[0018] Figure 6 It is a structural diagram of the interlayer protective plate.

[0019] In the figure: 1. Column group A; 2. Column group B; 3. Column group C; 4. Column group D; 5. First-layer horizontal connecting rod; 6. Second-layer horizontal connecting rod; 7. Third-layer horizontal connecting rod; 8. Lifting ring; 9. Interlayer protective plate; 10. Diagonal brace group A; 11. Diagonal brace group B; 12. Up and down stairs; 13. Platform panel; 14. Short diagonal brace; 15. Column group E; 16. Platform cross brace. DETAILED DESCRIPTION

[0020] like Figures 1 to 5 As shown, the utility model includes a column group, a horizontal connecting rod, a lifting ring 8, an interlayer protective plate 9, an upper and lower step ladder 12, a platform panel 13, and a platform cross brace 16; the column group includes an A column group 1, a B column group 2, a C column group 3, and a D column group 4; each column group has two vertically arranged columns, and the columns are all 50mm*50mm galvanized square tubes. The spacing between the columns in each column group is 700mm, and the lower ends of the two columns in each group are flush.

[0021] like Figure 1As shown, column group A 1 and column group B 2 are in the same plane, column group A 1 is located on the right side of column group B 2, and are 400mm apart; column group C 3 is located on the opposite side of column group A 1, and the vertical distance between column group C 3 and column group A 1 is 1900mm; column group D 4 is located on the opposite side of column group B 2, and is in the same plane as column group C 3; the horizontal connecting rods include a first-layer horizontal connecting rod 5, a second-layer horizontal connecting rod 6, and a third-layer horizontal connecting rod 7, and each layer of horizontal connecting rods is composed of a plurality of horizontally placed galvanized square tubes connected in sequence to the columns; the lifting ring 8 adopts horseshoe-shaped steel bars, which are welded to the four corners of the third-layer horizontal connecting rod 7, and the lifting ring 8 is set at a 45° angle to the third-layer horizontal connecting rod 7; the platform panel 13 is arranged on the second-layer horizontal connecting rod 6 and the platform cross brace 16 near the side of column group C 3 and column group D 4. The platform cross brace 16 is placed horizontally and parallel to the plane where the C column group 3 is located. The two ends of the platform cross brace 16 are vertically welded to the second-layer horizontal connecting rod 6 located between the outer columns of the A column group 1 and the C column group 3 and the B column group 2 and the D column group 4; the platform cross brace 16 and the second-layer horizontal connecting rod 6 are in the same horizontal plane; the up and down step ladders 12 are two groups, the starting position of the first group of up and down step ladders is located at the connection between the first horizontal connecting rod 5 and the A column group 1, and the ending position is located at the platform cross brace 16 corresponding to the C column group 3; the starting position of the second group of up and down step ladders is located at the platform cross brace 16 corresponding to the D column group 4, and the ending position is located at the connection between the B column group 2 and the first horizontal connecting rod 7.

[0022] In order to better play the role of reinforcement and protection, the utility model also adds a group of column groups, that is, the column group also includes an E column group 15; the lower ends of the two columns of the E column group 15 are flush and also use 50mm*50mm galvanized square tubes; the two columns of the E column group 15 are respectively opposite to the columns on the inner side of the C column group 3 and the D column group 4, and the vertical distance between the E column group 15 and the C column group 3 is 500mm; the top surface of the E column group 15 is flush with the upper surface of the third-layer horizontal connecting rod 7, and the bottom surface of the E column group 15 is connected to the upper surface of the platform cross brace 16.

[0023] like Figure 2As shown, the first-layer horizontal connecting rods 5 horizontally connect every two adjacent columns in column groups A 1 to D 4, with the upper surface of the first-layer horizontal connecting rods 5 being 2700mm away from the bottom surface of column group A 1. The second-layer horizontal connecting rods 6 horizontally connect every two adjacent columns in column groups C 3 and D 4, horizontally connect the two outer columns of column groups B 2 and D 4, horizontally connect the two outer columns of column groups A 1 and C 3, horizontally connect the two inner columns of column groups A 1 and B 2, horizontally connect the inner column of column group A 1 and the platform cross brace 16, and horizontally connect the inner column of column group B 2 and the platform cross brace 16. The second-layer horizontal connecting rods 6 are located directly above the first-layer horizontal connecting rods 5, with the upper surface of the second-layer horizontal connecting rods 6 being 1450mm away from the upper surface of the first-layer horizontal connecting rods 5. The third-layer horizontal connecting rod 7 horizontally connects each two adjacent columns in the A column group 1 and the B column group 2, horizontally connects the two outer columns in the A column group 1 and the C column group 3, horizontally connects the two outer columns in the B column group 2 and the D column group 4, horizontally connects the two outer columns in the C column group 3 and the D column group 4, and horizontally connects the corresponding columns in the A column group 1, the B column group 2 and the E column group 15 respectively; the upper surface of the third-layer horizontal connecting rod 7 is 2850mm away from the upper surface of the first-layer horizontal connecting rod 5.

[0024] The two columns of column group A 1 are both 6660mm long; the two columns of column group B 2 are of equal length; the lower end of column group B 2 is welded to the upper surface of the first-layer horizontal connecting rod 5, and the upper end of column group B 2 is flush with the upper end of column group A 1; the top of the inner column of column group B 2 is connected to the top of the inner column of column group A 1 through a cross brace; the top of the outer column of column group B 2 is connected to the top of the outer column of column group D 4 through a cross brace; the top of the outer column of column group C 3 is connected to the top of the outer column of column group D 4 through a cross brace; the top of the outer column of column group C 3 is connected to the top of the inner column of column group B 2 The ends are connected to the top ends of the outer columns of column group A 1 through cross braces; the top surfaces of the inner columns are vertically welded to the lower surface of the third horizontal connecting rod 7; the bottom surface of column group C 3 is 1150mm higher than the bottom surface of column group A 1; the upper ends of the outer columns of column group D 4 are flush with the upper ends of column group B 2; the top surfaces of the inner columns of column group D 4 are welded to the lower surface of the third-layer horizontal connecting rod 7, and the bottom surface of column group D 4 is 1490mm higher than the bottom surface of column group A 1.

[0025] like Figure 6 As shown, the interlayer protection plate 9 is made of 3mm patterned steel plate, and a patterned steel plate of equal length 700mm, height 50mm and thickness 3mm is vertically welded at 0mm and 60mm on the long side of one end of the interlayer protection plate 9. The groove formed is clamped on the first layer horizontal connecting rod 5 between the two columns of the A column group 1 and the third layer horizontal connecting rod 7 between the two columns of the B column group 2, so as to facilitate the fixation of the interlayer protection plate 9.

[0026] like Figure 5As shown, the platform panel 13 is made of 3mm patterned steel plate with a size of 2000mm*600mm. The platform panel 13 is provided with 50mm*50mm square holes at the positions corresponding to the columns of the C column group 3, the D column group 4, and the E column group 15, so as to facilitate the placement of the second-layer horizontal connecting rod 6 and the platform cross brace 16 on the side close to the C column group 3. The traditional 15mm wood plywood has the following disadvantages: short service life, non-recyclability, easy loosening of the board surface, low anti-slip coefficient, and the board surface is easily penetrated and damaged by objects. The platform panel 13 of the present invention is made of 3mm patterned steel plate with high rigidity, strong integrity and anti-slip surface, which can better meet the requirements of long-term stepping. At the same time, it has a long service life and can be recycled many times.

[0027] There are two groups of up and down stairs 12. The starting position of the first group of up and down stairs is at the part of the first horizontal connecting rod 5 between the two columns of the A column group 1, and the ending position is at the platform cross brace 16 corresponding to the C column group 3; the starting position of the second group of up and down stairs is at the platform cross brace 16 corresponding to the D column group 4, and the ending position is at the part of the third horizontal connecting rod 7 between the two columns of the B column group 2.

[0028] like Figure 1 and Figure 2 As shown, the lower part of the inner columns of the A column group 1 and the C column group 3 of the present invention is provided with an A diagonal brace group 10; the lower part of the outer columns of the B column group 2 and the D column group 4 is provided with a B diagonal brace group 11; the A diagonal brace group 10 and the B diagonal brace group 11 are both composed of two galvanized square tubes, and the specifications of the galvanized square tubes are 50mm*50mm. The outer columns of the A column group 1 and the second-layer horizontal connecting rod 6 are provided with short diagonal braces 14 in the up and down directions of the stairs; the outer columns of the D column group 4 and the third-layer horizontal connecting rod 7 are provided with short diagonal braces 14 in the up and down directions of the stairs; the inner columns of the A column group 1 and the second-layer horizontal connecting rod 6 are provided with short diagonal braces 14 in the up and down directions of the stairs, and the inner columns of the B column group 2 and the third-layer horizontal connecting rod 7 are provided with short diagonal braces 14 in the up and down directions of the stairs; a horizontal brace is added between the outer columns of the A column group 1 and the C column group 3 above the third-layer horizontal connecting rod 7; a horizontal brace is added between the outer columns of the B column group 2 and the D column group 4 above the third-layer horizontal connecting rod 7; the above-mentioned A diagonal brace group 10, B diagonal brace group 11, short diagonal braces 14, and horizontal braces are all for strengthening the overall structure and adding protective enclosures.

[0029] The columns, horizontal connecting rods, reinforced diagonal bracing groups, platform cross bracings, etc. of the present invention are preferably made of galvanized square tubes, mainly because of their small area, material saving, low cost, and meeting the construction cost reduction needs. In the specific construction test, a comparison was made with 16# I-beams, and it was found that if 16# I-beams were used as the main / secondary keels and diagonal supports, there would be problems such as large volume, heavy weight, difficult operation, and low construction efficiency. Moreover, due to the heavy weight, they could not fit completely with the wall when in contact, and there would be warping at the corners, and there would be waste of materials and high cost. Therefore, considering the convenience, stability, economy, and aesthetics, 50*50 galvanized square tubes were selected as the main and secondary keels and diagonal supports, namely the columns, horizontal connecting rods, diagonal bracing groups, platform cross bracings, etc. of the present invention.

[0030] The utility model is hoisted once after the floor concrete is poured. It has good integrity, high safety, small size, light weight, better contact and fit with the wall, easy operation, can effectively improve construction efficiency, ensure safety requirements, reduce construction and maintenance costs, and meet the requirements of energy saving and material saving.

[0031] The above-mentioned implementation manner is not a limitation of the present invention, and the present invention is not limited to the above-mentioned examples. Any changes, modifications, additions or substitutions made by technicians in this technical field within the scope of the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A special platform for assembled stairwells used at construction sites, characterized by: It comprises a column group, a horizontal connecting rod, a lifting ring (8), an interlayer protective plate (9), an upper and lower step ladder (12), a platform panel (13), and a platform cross brace (16); the column group comprises an A column group (1), a B column group (2), a C column group (3), and a D column group (4); each column group has two vertically arranged columns, the columns are made of galvanized square tubes, the distance between the columns in each column group is 700 mm, and the lower ends of the two columns in each group are flush; The A column group (1) and the B column group (2) are in the same plane, the A column group (1) is located on the right side of the B column group (2) and the distance between them is 400 mm; the C column group (3) is located on the opposite side of the A column group (1), and the vertical distance between the C column group (3) and the A column group (1) is 1900 mm; the D column group (4) is located on the opposite side of the B column group (2) and is in the same plane as the C column group (3); The horizontal connecting rods include a first-layer horizontal connecting rod (5), a second-layer horizontal connecting rod (6), and a third-layer horizontal connecting rod (7), and each layer of horizontal connecting rods is formed by connecting columns in sequence with a plurality of horizontally placed galvanized square tubes; the hoisting ring (8) is made of horseshoe-shaped steel bars and is welded to the four corners of the third-layer horizontal connecting rod (7), and the hoisting ring (8) and the third-layer horizontal connecting rod (7) are arranged at an angle of 45°; the platform panel (13) is arranged on the second-layer horizontal connecting rod (6) and the platform cross brace (16) on one side close to the C column group (3) and the D column group (4); The platform cross brace (16) is placed horizontally and parallel to the plane where the C column group (3) is located. The two ends of the platform cross brace (16) are vertically welded to the second-layer horizontal connecting rod (6) located on the connecting rod between the outer columns of the A column group (1) and the C column group (3) and the B column group (2) and the D column group (4); the platform cross brace (16) and the second-layer horizontal connecting rod (6) are in the same horizontal plane; The up and down step ladders (12) are divided into two groups. The starting position of the first group of up and down step ladders is located at the part of the first layer horizontal connecting rod (5) between the two columns of the A column group (1), and the ending position is located at the platform cross brace (16) corresponding to the C column group (3); the starting position of the second group of up and down step ladders is located at the part of the platform cross brace (16) corresponding to the D column group (4), and the ending position is located at the part of the third layer horizontal connecting rod (7) between the two columns of the B column group (2).

2. The special platform for assembled stairwells for construction sites according to claim 1, characterized in that: The column group also includes an E column group (15); the lower ends of the two columns of the E column group (15) are flush; the two columns of the E column group (15) are respectively opposite to the columns on the inner sides of the C column group (3) and the D column group (4), and the vertical distance between the E column group (15) and the C column group (3) is 500 mm; the top surface of the E column group (15) is flush with the upper surface of the third-layer horizontal connecting rod (7), and the bottom surface of the E column group (15) is connected to the upper surface of the platform cross brace (16).

3. The special platform for assembled stairwells for construction sites according to claim 2, characterized in that: The first-layer horizontal connecting rod (5) horizontally connects every two adjacent columns in the A column group (1) to the D column group (4), and the upper surface of the first-layer horizontal connecting rod (5) is 2700 mm away from the bottom surface of the A column group (1); The second-layer horizontal connecting rod (6) horizontally connects two adjacent columns in the C column group (3) and the D column group (4), horizontally connects the two columns on the outside of the B column group (2) and the D column group (4), horizontally connects the two columns on the outside of the A column group (1) and the C column group (3), horizontally connects the two columns on the inside of the A column group (1) and the B column group (2), horizontally connects the columns on the inside of the A column group (1) and the platform cross brace (16), and horizontally connects the columns on the inside of the B column group (2) and the platform cross brace (16); the second-layer horizontal connecting rod (6) is located directly above the first-layer horizontal connecting rod (5), and the distance between the upper surface of the second-layer horizontal connecting rod (6) and the upper surface of the first-layer horizontal connecting rod (5) is 1450 mm; The third-layer horizontal connecting rod (7) sequentially and horizontally connects each two adjacent columns in the A column group (1) and the B column group (2), horizontally connects the two middle and outer columns in the A column group (1) and the C column group (3), horizontally connects the two middle and outer columns in the B column group (2) and the D column group (4), horizontally connects the two middle and outer columns in the C column group (3) and the D column group (4), and horizontally connects the corresponding columns in the A column group (1), the B column group (2) and the E column group (15); the upper surface of the third-layer horizontal connecting rod (7) is 2850 mm away from the upper surface of the first-layer horizontal connecting rod (5).

4. The special platform for assembled stairwells for construction sites according to claim 1, characterized in that: The interlayer protection plate (9) is made of 3mm patterned steel plate, and a patterned steel plate with the same length of 700mm, height of 50mm and thickness of 3mm is vertically welded at 0mm and 60mm on the long side of one end of the interlayer protection plate (9).

5. The special platform for assembled stairwells for construction sites according to claim 1, characterized in that: The platform panel (13) is made of 3mm patterned steel plate with a size of 2000mm*600mm. The platform panel (13) is provided with 50mm*50mm square holes at positions corresponding to the columns of the C column group (3), the D column group (4), and the E column group (15).

6. The special platform for assembled stairwells for construction sites according to claim 1, characterized in that: The two columns of the A column group (1) are both 6660 mm long; the two columns of the B column group (2) are of equal length; the lower end of the B column group (2) is welded to the upper surface of the first layer of horizontal connecting rods (5), and the upper end of the B column group (2) is flush with the upper end of the A column group (1); the top of the inner column of the B column group (2) is connected to the top of the inner column of the A column group (1) through a cross brace; the top of the outer column of the B column group (2) is connected to the top of the outer column of the D column group (4) through a cross brace; the outer column of the C column group (3) is connected to the outer column of the D column group (4) through a cross brace. The top of the column is connected to the top of the column on the outside of the A column group (1) through a cross brace; the top surface of the inner column is vertically welded to the lower surface of the third-layer horizontal connecting rod (7); the bottom surface of the C column group (3) is 1150mm higher than the bottom surface of the A column group (1); the upper end of the column on the outside of the D column group (4) is flush with the upper end of the B column group (2); the top surface of the inner column of the D column group (4) is welded to the lower surface of the third-layer horizontal connecting rod (7), and the bottom surface of the D column group (4) is 1490mm higher than the bottom surface of the A column group (1).

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