A construction method for a free-form concrete thick-shell tie rod system

Abstract

This invention relates to a construction method for a free-form concrete thick shell tie rod system, comprising: bottom formwork construction; laying the bottom layer of reinforcing steel; drilling tie rod holes in the bottom formwork; inserting the lower first tie rod; laying the next layer of reinforcing steel and connecting the next tie rod; repeating the previous step until the top of the tie rod reaches the upper surface reinforcing steel layer of the thick shell and then connecting the two; covering and precisely positioning the upper surface formwork, marking the location of the tie rod holes in the upper surface formwork; removing the upper surface curved formwork; welding the upper first tie rod; covering and precisely positioning the upper surface formwork again; connecting the upper second tie rod; sealing and reinforcing the upper surface tie rod holes. This invention's construction method for a free-form concrete thick shell tie rod system solves the problem of not being able to construct tie rods on both sides of the free-form concrete thick shell formwork, ensuring that the formwork support system has sufficient horizontal lateral bearing capacity to meet construction requirements.

Description

Technical Field

[0001] This invention relates to the field of civil engineering construction, specifically to a construction method for a free-form concrete thick shell tie rod system. Background Technology

[0002] Unlike planar or gently sloping concrete structures, cast-in-place reinforced concrete sloping panels, shells, and inclined walls with steep slopes require a double-sided formwork system during construction. The lower formwork needs vertical supports similar to those used for horizontal construction, and a horizontal lateral force balancing system, such as tie rods, is also required between the two sides of the formwork. However, using both support systems simultaneously can lead to limited construction space, necessitating careful attention to the construction sequence.

[0003] When the thickness of the sloping panel, shell, and sloping wall is large, the self-weight of the component increases, requiring the strengthening of the vertical support system's bearing capacity. More importantly, the steel bars of thicker components often have more layers and are denser. If the tie rods are inserted in the conventional order after the bottom support, bottom formwork, and all steel bars are completed, the excessive and dense steel bars will make it almost impossible to insert the tie rods, making the construction very difficult.

[0004] However, for thick curved concrete cast-in-place slabs, shells, and curved walls (hereinafter referred to as thick curved concrete shells), especially free-form thick curved concrete shells with large curvature, the reinforcement is not only more numerous and denser than that of planar components, but its arrangement often follows the curvature of the surface, further increasing the difficulty of threading tie rods. Furthermore, curved concrete often uses custom-made curved formwork, which comes in many varieties, but generally cannot be used to create holes at will according to the location of the tie rods on site; various openings must be pre-drilled, which further increases the difficulty of threading tie rods through pre-drilled openings. Therefore, for this type of free-form curved cast-in-place thick concrete shell structure, the existing formwork support, tie rod system, and construction technology cannot meet the construction requirements, and there is no clearly feasible construction method, presenting a technical barrier.

[0005] Existing technology (CN110424640A) discloses a construction method for a sloping roof concrete structure, which includes the following steps: S1, constructing a sloping roof support system; S2, erecting a bottom formwork on the sloping surface of the sloping roof support system; S3, tying a reinforcing cage to the side of the bottom formwork away from the sloping roof support system; S4, roughening the joint between the sloping roof and the lower building structure; S5, erecting an outer formwork on the side of the reinforcing cage away from the bottom formwork and reinforcing the outer formwork; S6, pouring concrete; S7, after the concrete has solidified, removing the outer formwork and the bottom formwork. This method uses a double-formwork structure, ensuring that the sloping roof panel formed after concrete pouring has good flatness, no honeycomb or pitted surface, and good connection with the joint, but it does not solve the problem of the high construction difficulty of the tie rod system. Summary of the Invention

[0006] To address the technical problems existing in the prior art, this invention provides a construction method for a free-form concrete thick shell tie rod system, which can solve the problem of the inability to construct tie rods on both sides of the free-form concrete thick shell formwork, and ensure that the formwork support system has sufficient horizontal lateral bearing capacity to meet construction requirements.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A construction method for a free-form concrete thick-shell tie rod system, comprising the following steps:

[0009] Step 1: Construct the support system under the bottom formwork of the free-form concrete thick shell, and lay and fix the bottom formwork.

[0010] Step 2: Lay the bottom layer of reinforced concrete shell, pre-drill holes for tie rods in the bottom formwork, and pass the first section of tie rods through the holes to fix them to the bottom formwork.

[0011] Step 3: Continue laying the next layer of steel reinforcement for the thick concrete shell. Based on the height of the next layer of steel reinforcement, connect the next section of tie rod to the first section of tie rod at the bottom.

[0012] Step 4: Repeat Step 3 until the top of the tie rod reaches the upper surface steel reinforcement layer of the thick concrete shell, connect the tie rod to the upper surface steel reinforcement layer, and cut off the excess section of the tie rod that extends beyond the upper surface steel reinforcement layer.

[0013] Step 5: On the upper surface curved template of the thick concrete shell, make tie rod holes according to the tie rod arrangement spacing;

[0014] Step 6: First, cover the upper curved surface template onto the thick concrete shell reinforcement and position it.

[0015] Step 7: After positioning is completed, mark the hole positions on the upper surface of the concrete thick shell steel bars through the tie rod holes on the upper surface.

[0016] Step 8: After marking all hole locations, remove the upper surface curved template;

[0017] Step 9: Weld the first tie rod at the marked location on the upper surface of the reinforcing bar;

[0018] Step 10: Cover the upper curved surface template onto the reinforced concrete shell again and position it.

[0019] Step 11: Connect the second section of the upper tie rod to the first section of the upper tie rod through the tie rod hole on the upper surface;

[0020] Step 12: Seal the tie rod holes on the upper surface and fix the upper tie rod to the upper curved surface template to complete the construction of the free-form concrete thick shell tie rod system.

[0021] As a preferred technical solution, in step two, the bottom template is a customized free-form surface template, and the first section of tie rod is fixedly connected to the bottom template through a mountain-shaped clamp and a steel pipe.

[0022] As a preferred technical solution, in step three, according to the spacing of the reinforcing bars in each layer and the length of the tie rod, before constructing the first tie rod section at the bottom, a middle layer of reinforcing bars is laid in the thick concrete shell, avoiding the holes of the tie rod when laying the reinforcing bars.

[0023] As a preferred technical solution, in step seven, the location of the holes is marked by brushing paint.

[0024] As a preferred technical solution, in step nine, a water-stop nut is pre-installed on the top of the upper first section of the tie rod, and in step eleven, the upper second section of the tie rod is connected to the upper first section of the tie rod through the water-stop nut.

[0025] As a preferred technical solution, when the curvature of the concrete thick shell surface is small, in step nine, the top of the upper first section tie rod extends out of the concrete surface, thus omitting step eleven.

[0026] As a preferred technical solution, the tie rod adopts a bolt-type screw.

[0027] Compared with the prior art, the beneficial effects of the construction method of the free-form concrete thick shell tie rod system of the present invention are as follows:

[0028] (1) By using the structural steel reinforcement layer as the force transfer layer of the segmented tie rod, the problem that the entire tie rod cannot pass through the steel reinforcement layer with many layers, dense distribution and inconsistent direction in the free-form concrete thick shell in one go is solved;

[0029] (2) The lower part of the transfer layer adopts a segmented tie rod system. The tie rod is constructed layer by layer, which greatly improves the convenience of construction of each steel reinforcement layer; otherwise, the construction of a tie rod that is too long at one time will cause great obstacles to the construction of the middle steel reinforcement layer.

[0030] (3) The segmented tie rod system on the upper part of the conversion layer can solve the problem that when the curvature of the curved surface is large, the customized template of the curved surface cannot pass through the tie rod that is too long in one construction.

[0031] (4) The tie rod holes on the customized template can be opened arbitrarily; the difficulty of mold detailing design is reduced; the accuracy requirements for the positioning and opening of tie rod holes in the production and processing of curved templates are reduced; the problem of sealing tie rod holes is solved; the situation of secondary hole opening or hole enlargement on the construction site is avoided; for customized templates that need to be reused, the damage to customized templates caused by on-site hole opening is further reduced, thereby ensuring the number of template turnovers and saving the construction cost of free-form concrete structures. Attached Figure Description

[0032] Figure 1 This is an operation flowchart of a construction method for a free-form concrete thick shell tie rod system according to the present invention;

[0033] Figure 2 This is a schematic diagram of step two in the construction method of a free-form concrete thick shell tie rod system according to the present invention.

[0034] Figure 3 This is a schematic diagram of step three in the construction method of a free-form concrete thick shell tie rod system according to the present invention;

[0035] Figure 4 This is a schematic diagram of step four in the construction method of a free-form concrete thick shell tie rod system according to the present invention.

[0036] Figure 5 This is a schematic diagram of step six in the construction method of a free-form concrete thick shell tie rod system according to the present invention;

[0037] Figure 6 This is a schematic diagram of step eight in the construction method of a free-form concrete thick shell tie rod system of the present invention.

[0038] Figure 7 This is a schematic diagram of step ten in the construction method of a free-form concrete thick shell tie rod system according to the present invention.

[0039] In the diagram: 1. Support system; 2. Bottom formwork; 3. Bottom layer reinforcement of the thick concrete shell; 4. Tie rod holes in the bottom formwork; 5. Lower first section of tie rod; 6. Mountain-shaped clamp; 7. Steel pipe; 8. Middle two layers of reinforcement in the thick concrete shell; 9. Lower second section of tie rod; 10. Top two layers of reinforcement in the thick concrete shell; 11. Lower last section of tie rod; 12. Upper curved formwork; 13. Tie rod holes on the upper surface; 14. Hole location markings; 15. Upper first section of tie rod; 16. Water-stop nut; 17. Upper second section of tie rod. Detailed Implementation

[0040] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0041] A construction method for a free-form concrete thick shell tie rod system. In this embodiment, a free-form concrete thick shell structure with a thickness of 800 mm contains 6 layers of bidirectional reinforcing bars. Figure 1 As shown, the construction method of the tie rod system of the present invention includes the following steps:

[0042] Step 1, as follows Figure 2 As shown, the support system 1 is located below the bottom formwork 2 of the free-form concrete thick shell. The bottom formwork 2 is laid and fixed. The bottom formwork 2 is a customized free-form formwork.

[0043] Step two, as Figure 3 As shown, the bottom layer of reinforced concrete shell 3 is laid. Tie rod holes 4 are pre-drilled in the bottom formwork 2. Based on the spacing of each layer of reinforcement and the length of the tie rods, the middle two layers of reinforced concrete shell 8 are laid before constructing the first section of tie rods. The reinforcement is laid away from the tie rod holes. The first section of tie rods 5 is passed through the tie rod holes 4 in the bottom formwork, and is fixedly connected to the bottom formwork 2 using U-shaped clamps 6 and steel pipes 7. In this embodiment, all tie rods are connected by threads.

[0044] Step 3, as Figure 3 As shown, continue laying the next layer of steel reinforcement for the thick concrete shell. Based on the height of the next layer of steel reinforcement, connect the second section of tie rod to the first section of tie rod 5 at the bottom.

[0045] Step four, as Figure 4As shown, repeat step three to continue laying the top two layers of reinforcing bars 10 of the concrete shell. Connect the bottom third tie rod 11 to the bottom second tie rod 9. In this embodiment, the bottom third tie rod 11 is the bottom last tie rod. Cut off the excess section of the bottom third tie rod 11 that extends beyond the top two layers of reinforcing bars 10 of the concrete shell, or bend the top of the bottom third tie rod 11, and then weld the bottom third tie rod 11 to the top two layers of reinforcing bars 10 of the concrete shell.

[0046] Step 5: On the upper surface curved template 12 of the thick concrete shell, make upper surface tie rod holes 13 according to the tie rod arrangement spacing;

[0047] Step six, as follows Figure 5 As shown, the upper surface curved template 12 is first placed on the two layers of steel bars 10 on top of the thick concrete shell, and positioned according to the accuracy requirements; in this embodiment, the upper surface curved template 12 is also a customized free-form template.

[0048] Step 7: After positioning is completed, mark the hole positions 14 on the two layers of steel bars 10 at the top of the concrete thick shell by using paint through the upper surface tie rod holes 13 pre-drilled on the upper surface curved template 12.

[0049] Step eight, as Figure 6 As shown, after all hole locations 14 are marked, remove the upper surface curved template 12;

[0050] Step 9: Weld the upper first section tie rod 15 at the marked hole position 14 on the two layers of steel bars 10 at the top of the concrete thick shell, and pre-install water-stop nuts 16 on the top of the upper first section tie rod 15.

[0051] Step 10, as follows Figure 7 As shown, the upper surface curved template 12 is once again placed over the two layers of steel bars 10 on top of the concrete thick shell and positioned.

[0052] Step 11: Connect the upper second tie rod 17 to the upper first tie rod 15 through the tie rod hole 13 on the upper surface and the water-stop nut 16;

[0053] When the curvature of the concrete shell is small, the top of the first tie rod 15 extends directly out of the concrete surface, and the upper surface curved template 12 directly covers the two layers of steel bars 10 at the top of the concrete shell. In this case, step eleven can be omitted, and the upper tie rod does not need to be segmented.

[0054] Step 12: Seal the tie rod hole 13 on the upper surface and fix the upper second tie rod 17 to the upper curved template 12 to complete the construction of the free-form concrete thick shell tie rod system.

[0055] This embodiment is merely a further explanation of the present invention and is not intended to limit the present invention. Those skilled in the art can make non-inventive modifications to this embodiment as needed after reading this specification, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A construction method for a free-form concrete thick-shell tie rod system, characterized in that, The method includes the following steps: Step 1: Construct the support system under the bottom formwork of the free-form concrete thick shell, and lay and fix the bottom formwork. Step 2: Lay the bottom layer of reinforced concrete shell. Pre-drill holes for tie rods in the bottom template and pass the first section of tie rods through the holes to fix them to the bottom template. Step 3: Continue laying the next layer of steel reinforcement for the thick concrete shell. Based on the height of the next layer of steel reinforcement, connect the next section of tie rod to the first section of tie rod at the bottom. Step 4: Repeat Step 3 until the top of the tie rod reaches the upper surface steel reinforcement layer of the concrete shell, connect the tie rod to the upper surface steel reinforcement layer, and cut off the excess section of the tie rod that extends beyond the upper surface steel reinforcement layer. Step 5: On the upper surface curved template of the concrete thick shell, make tie rod holes according to the tie rod arrangement spacing; Step 6: First, cover the upper surface curved template onto the thick concrete shell reinforcement and position it. Step 7: After positioning is completed, mark the hole positions on the upper surface of the concrete thick shell steel bars through the tie rod holes on the upper surface. Step 8: After all hole locations have been marked, remove the upper surface curved template; Step 9: Weld the first section of the upper tie rod at the marked location on the upper surface reinforcing bar; Step 10: Cover the upper surface curved template onto the concrete thick shell reinforcement again and position it. Step 11: Connect the upper second section of the tie rod to the upper first section of the tie rod through the tie rod hole on the upper surface; Step 12: Seal the tie rod holes on the upper surface and fix the upper tie rod to the upper surface curved template to complete the construction of the free-form concrete thick shell tie rod system.

2. The construction method of a free-form concrete thick shell tie rod system according to claim 1, characterized in that, In step two, the bottom template is a customized free-form surface template, and the first tie rod is fixedly connected to the bottom template by a mountain-shaped clamp and a steel pipe.

3. The construction method of a free-form concrete thick shell tie rod system according to claim 1, wherein in step three, according to the spacing of each layer of reinforcing bars and the length of the tie rod, before constructing the lower first section of tie rod, a middle layer of reinforcing bars is laid in the concrete thick shell, avoiding the tie rod holes when laying the reinforcing bars.

4. The construction method of a free-form concrete thick shell tie rod system according to claim 1, characterized in that, In step seven, the locations of the holes are marked by applying paint.

5. The construction method of a free-form concrete thick shell tie rod system according to claim 1, characterized in that, In step nine, a water-stop nut is pre-installed on the top of the upper first section of the tie rod. In step eleven, the upper second section of the tie rod is connected to the upper first section of the tie rod through the water-stop nut.

6. The construction method of a free-form concrete thick shell tie rod system according to claim 1, characterized in that, When the curvature of the concrete shell is small, in step nine, the top of the first tie rod at the top extends out of the concrete surface, thus omitting step eleven.

7. The construction method of a free-form concrete thick shell tie rod system according to claim 1, characterized in that, The tie rod is a bolt-type screw.

Images