Construction method of fabricated circular open caisson

Abstract

A construction method of an assembly type circular open caisson comprises the steps that firstly, assembly type open caisson pieces are produced through a standardized factory, a customized steel mold and a steam curing production line; 2, blade foot pad layer concrete is poured in advance on site, a flat car is adopted for transporting the pipe pieces to the open caisson construction site, the pipe pieces are assembled into ring pipes through high-strength bolts on site, longitudinal ring pieces are spliced in a staggered joint mode, and joints are waterproof through double elastic sealing gaskets; 3, assembling the fabricated open caisson segments into two layers to implement the first sinking construction of the open caisson; 4, when the assembly type open caisson sinks to be flush with the ground, the number of the assembly pipe pieces continues to be increased, and the sinking depth of the assembly type open caisson is continuously increased till the assembly type open caisson sinks to the designed depth; and 5, open caisson bottom sealing and bottom plate construction are carried out. By the adoption of the assembly type mode, the assembly type open caisson is easy to assemble and high in assembly speed, the open caisson construction period is greatly shortened, the working efficiency is more effectively improved, and the construction period is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of underground pipe gallery construction and relates to a construction method of an assembled circular caisson. Background Art

[0002] The renovation and construction of the rainwater and sewage separation network is an important part of the development of municipal pipeline construction. It not only bears the important responsibility of urban flood control and drainage, but also plays an important role in source control for the treatment of downstream black and odorous water bodies. Therefore, paying attention to the construction safety, quality, construction period, cost and other issues in the process of renovation and construction of the rainwater and sewage separation network is the focus of the current work of the construction unit. Traditional caisson construction generally uses cast-in-place reinforced concrete circular caissons and cast-in-place reinforced concrete square caissons. There are problems with on-site formwork materials, scaffolding, and labor loss. The construction of cast-in-place reinforced concrete caissons involves many dangerous and major projects, and the long maintenance time delays the construction period. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a construction method for an assembled circular caisson, which adopts an assembly method to facilitate assembly, reduce labor loss, shorten construction period, reduce construction difficulty, and reduce project cost.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a construction method of an assembled circular caisson, comprising the following steps: Step 1: Use standardized factories, customized steel molds, and steam-cured production lines to produce assembled caisson segments; Step 2: pour the blade foot cushion concrete on site in advance, use a flatbed truck to transport the pipe segments to the caisson construction site, assemble the pipe segments into ring pipes on site with high-strength bolts, and use staggered joints for longitudinal ring segments. Double-pass elastic sealing pads are used for waterproofing the joints. Step 3, assembling two layers of prefabricated caisson segments to implement the first sinking construction of the caisson; Step 4: When the assembled caisson sinks to the ground level, continue to add assembled segments and continuously increase the sinking depth of the assembled caisson until the assembled caisson sinks to the designed depth; Step 5, implement the caisson bottom sealing and bottom plate construction.

[0005] In step 1, grooves are provided in the horizontal and vertical directions of the ring segments, and two adjacent ring segments are connected by a number of high-strength bolts, and rain-expandable water stop strips are provided in the grooves.

[0006] In step 1, a blade foot is provided at the sinking end of the caisson, and the blade foot is at a certain angle to the horizontal direction.

[0007] In step 1, the size of each segment unit is consistent to form a replacement segment; the longitudinal splicing size of the caisson is controlled to achieve continuous construction.

[0008] In step 3, to ensure uniform sinking of the caisson, uniform excavation of the earth in the caisson is the primary condition. At the same time, key measures are taken to assist the caisson to sink safely and smoothly, including waxing measures and mud-assisted sinking measures in the later stages of sinking.

[0009] In step 3, scouring protection is carried out around the caisson in the later stage of sinking, and water spraying and waxing measures are used to prevent stagnation.

[0010] In step 3, the caisson wall thickness is determined by three factors: Satisfy the need for sinking; the sinking coefficient is between 1.10 and 1.25; if it is less than 1.05, it must be thickened; if it is greater than 1.25, it must be thinned. If it cannot be thinned, the height of the caisson should be reduced during sinking, that is, the deadweight of the well should be reduced; Meet the requirements of structural strength and rigidity; the determination of the wall thickness of the caisson is related to the arrangement of the vertical and horizontal wall beams in the well, and the structural strength and rigidity must be checked to determine whether the reinforcement is appropriate; To meet the anti-floating requirements, anti-floating calculations should be carried out during the construction period and the operation period after the bottom is sealed to determine whether the thickness of the caisson wall is appropriate.

[0011] In step 2, the connection method of the segments is that a number of mortises are pre-buried in an annular direction on both sides of the annular segments, and double elastic sealing pads are added in the horizontal mortise and tenon grooves for waterproofing. During the installation process, the horizontal connection holes temporarily serve as lifting holes for lifting installation.

[0012] In step 2, the blade foot cushion layer concrete is poured in advance on site and then the blade foot ring segments are installed; in order to ensure the overall strength of the caisson during construction, a reinforcement ring caisson is spliced ​​on the blade foot ring, and a double-channel elastic sealing pad is also added to the plane of the caisson ring for waterproofing.

[0013] In step 2, two adjacent ring segments are longitudinally connected by a plurality of high-strength bolt connectors; the two ends of the connectors are respectively buckled into the corresponding grooves of the two adjacent ring segments, and the adjacent ring segments are also connected by high-strength threaded bolts.

[0014] The main beneficial effects of the present invention are: The prefabrication of the pipe segments is separated from the construction site, there is basically no material stacking on site, and the construction site occupies a small area.

[0015] The segments are prefabricated in factories, with good construction conditions and easy quality control.

[0016] The number of on-site workers and the amount of work required on-site are small, and the difficulty of construction safety control is reduced.

[0017] The construction cost is lower than the original construction mode.

[0018] Prefabrication and on-site installation and sinking are carried out in parallel, which avoids the time required for concrete strength growth in the on-site cast-in-place method and speeds up the construction.

[0019] According to the sinking conditions of on-site construction, the installation height of the upper pipe segment can be flexibly increased or decreased, and the construction speed can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 It is a schematic structural diagram of the assembled caisson of the present invention.

[0022] Figure 2 It is a schematic diagram of the structure of one side of the ring tube segment blade foot ring of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the segment reinforcement ring and standard ring on one side.

[0024] Figure 4 It is a schematic diagram of the annular connection concave surface structure of the tenon grooves connecting two rings of pipe segments.

[0025] Figure 5 It is a schematic diagram of the convex structure of the annular connection of the tenon grooves of two connected rings of pipe segments.

[0026] Figure 6 It is a schematic diagram of the vertical connection concave structure of the tenon grooves connecting two rings of pipe segments.

[0027] Figure 7 It is a schematic diagram of the vertical connection convex structure of the tenon grooves connecting two rings of pipe segments.

[0028] In the figure: 1. segment; 11. segment unit; 12. blade foot ring; 13. reinforcement ring; 14. standard ring; 2. longitudinal connecting hole; 21. horizontal connecting hole; 3. mortise and tenon convex surface; 4. blade foot. DETAILED DESCRIPTION

[0029] like Figure 1 to Figure 7 A construction method of an assembled circular caisson comprises the following steps: Step 1: Use standardized factories, customized steel molds, and steam-cured production lines to produce assembled caisson segments; Step 2: pour the blade foot cushion concrete on site in advance, use a flatbed truck to transport the pipe segments to the caisson construction site, assemble the pipe segments into ring pipes on site with high-strength bolts, and use staggered joints for longitudinal ring segments. Double-pass elastic sealing pads are used for waterproofing the joints. Step 3, assembling two layers of prefabricated caisson segments to implement the first sinking construction of the caisson; Step 4: When the assembled caisson sinks to the ground level, continue to add assembled segments and continuously increase the sinking depth of the assembled caisson until the assembled caisson sinks to the designed depth; Step 5, implement the caisson bottom sealing and bottom plate construction.

[0030] Embodiment 1, By adopting the above technical scheme, the present invention ensures uniform sinking of the caisson. Uniform excavation of earth in the caisson is the primary condition. At the same time, key measures are taken to assist the caisson to sink safely and smoothly, including wax coating measures, mud-assisted sinking auxiliary measures in the later stage of sinking, etc.

[0031] Cast-in-place reinforced concrete is poured on site as a whole. The caisson is prone to tilt and cracks during the sinking process. If tilting occurs during sinking, it will affect the next reinforcement binding and concrete pouring. The construction method of the assembled caisson is adopted: each pipe segment unit is of the same size to form a replacement pipe segment. A pipe segment unit can be randomly picked up on site to splice the pipe segments of the caisson. The unit factory is processed and manufactured with high precision, high strength, not easy to crack, short construction time, and the longitudinal splicing size of the caisson can be controlled. Continuous construction can be achieved without a waiting period, the load-bearing efficiency of the caisson is improved, and the structure is simple. Grooves are provided in the horizontal and vertical directions of the annular segments. Adjacent annular segments are connected by a number of high-strength bolts. Waterstop strips that expand when exposed to rain are provided in the grooves. When the waterstop strips are under pressure, they will expand and fill the gaps when encountering water, thus achieving a water-stopping effect.

[0032] The sinking end of the caisson is provided with a blade foot, and the blade foot is at a certain angle to the horizontal direction. The blade foot is at a certain angle to the horizontal direction, which can reduce the resistance at the end of the blade foot of the caisson and speed up the sinking speed of the caisson.

[0033] By adopting the above technical solution, the high-strength bolt connector of the present invention is customized into a prefabricated part with an arc that matches the reserved hole. The structure is easy to construct and has a strong fastening force between the annular segments. By adopting the above technical scheme, the present invention performs scouring protection around the caisson in the later stage of sinking, and can solve the problem of stagnant sinking by measures such as spraying water and brushing wax; uniform sinking, monitoring, timely and slow correction, and maintaining a good geometric posture are the core elements to ensure the safety of the caisson structure and smooth construction.

[0034] Embodiment 2, The segment units 11 are manufactured in a factory, transported to the caisson site after manufacture, and installed on site to form an annular segment 1. A plurality of annular segments 1 are longitudinally assembled to complete at least a portion of the caisson; The thickness of the caisson wall is usually determined by the following three factors: ① Satisfy the need for sinking. According to construction experience, the best sinking coefficient is between 1.10 and 1.25. If it is less than 1.05, it must be thickened; if it is greater than 1.25, it must be thinned. If it cannot be thinned, the height of the caisson should be reduced during sinking, that is, the deadweight of the well should be reduced; ② Meet the requirements of structural strength and rigidity. The determination of the thickness of the caisson wall is related to the arrangement of the vertical and horizontal wall beams in the well. The structural strength and rigidity calculation must be carried out to determine whether the reinforcement is appropriate; ③ Satisfy the need for anti-floating. Anti-floating calculations should be carried out during the construction period and the operation period after the bottom is sealed to determine whether the thickness of the caisson wall is appropriate.

[0035] Embodiment 3, The specific connection method of the pipe segments is that a plurality of mortises 3 are pre-buried in an annular direction on both sides of the annular pipe segment 11, and double elastic sealing pads are added in the horizontal mortise and tenon for waterproofing; during the installation process, the horizontal connection holes 21 temporarily serve as lifting holes for lifting installation.

[0036] The blade foot cushion layer concrete is poured in advance on site and 12 blade foot ring segments are installed.

[0037] In order to ensure the overall strength of the caisson during the construction process, a 13-reinforcement ring caisson is spliced ​​on the 12-blade foot ring, and a double-channel elastic sealing pad is also added to the plane of the caisson ring for waterproofing.

[0038] Two adjacent ring segments 11 are longitudinally connected by a plurality of high-strength bolt connectors 2, the two ends of the connectors are respectively buckled into the corresponding grooves 3, 31 of the two adjacent ring segments 11, and the adjacent ring segments are also connected by high-strength threaded bolts.

[0039] Embodiment 4, like Figures 4 to 7 middle, Figure 4 It is a schematic diagram of the annular connection concave surface structure of the tenon grooves of two connected ring segments; Figure 5 It is a schematic diagram of the convex structure of the annular connection of the tenon grooves of two connected ring segments; Figure 6 It is a schematic diagram of the vertical connection concave surface structure of the tenon grooves of two connected ring segments; Figure 7 It is a schematic diagram of the vertical connection convex structure of the tenon grooves connecting two rings of pipe segments.

[0040] The dimension table of segment connection structure is as follows:

[0041] In the above embodiments, (1) Segment prefabrication is separated from the construction site, there is basically no material stacking on site, and the construction site occupies a small area; (2) The segments are prefabricated in the factory, with good construction conditions and easy quality control; (3) The number of on-site workers and the amount of on-site work required are small, and the difficulty of construction safety control is reduced; (4) The construction cost is lower than the original construction model; (5) Prefabrication and on-site installation and sinking are carried out in parallel, which avoids the time required for concrete strength growth in the on-site cast-in-place method and speeds up the construction; (6) According to the sinking conditions of on-site construction, the installation height of the upper segment can be flexibly increased or decreased, and the construction speed can be controlled. The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for constructing an assembled circular caisson, characterized in that: The steps include: Step 1: Use standardized factories, customized steel molds, and steam-cured production lines to produce assembled caisson segments; Step 2: pour the blade foot cushion concrete in advance on site, use a flatbed truck to transport the pipe segments to the caisson construction site, assemble the pipe segments into ring pipes on site with high-strength bolts, and use staggered joints for longitudinal ring segments. Double-pass elastic sealing pads are used for waterproofing the joints. Step 3, assembling two layers of prefabricated caisson segments to implement the first sinking construction of the caisson; Step 4: When the assembled caisson sinks to the ground level, continue to add assembled segments and continuously increase the sinking depth of the assembled caisson until the assembled caisson sinks to the designed depth; Step 5, implement the caisson bottom sealing and bottom plate construction.

2. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 1, grooves are provided in the horizontal and vertical directions of the ring segments, and two adjacent ring segments are connected by a number of high-strength bolts, and rain-expandable water stop strips are provided in the grooves.

3. The construction method of the assembled circular caisson according to claim 1 is characterized by: In step 1, a blade foot is provided at the sinking end of the caisson, and the blade foot is at a certain angle to the horizontal direction.

4. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 1, each segment unit has the same size to form a replacement segment; the longitudinal splicing size of the caisson is controlled to achieve continuous construction.

5. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 3, to ensure uniform sinking of the caisson, uniform excavation of the earth in the caisson is the primary condition. At the same time, key measures are taken to assist the caisson to sink safely and smoothly, including waxing measures and mud-assisted sinking measures in the later stages of sinking.

6. The construction method of the assembled circular caisson according to claim 5 is characterized in that: In step 3, flushing protection is carried out around the caisson in the later stage of sinking, and water spraying and waxing measures are used to prevent stagnation.

7. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 3, the caisson wall thickness is determined by three factors: Satisfy the need for sinking; the sinking coefficient is between 1.10 and 1.25; if it is less than 1.05, it must be thickened; if it is greater than 1.25, it must be thinned. If it cannot be thinned, the height of the caisson should be reduced during sinking, that is, the deadweight of the well should be reduced; Meet the requirements of structural strength and rigidity; the determination of the wall thickness of the caisson is related to the arrangement of the vertical and horizontal wall beams in the well, and the structural strength and rigidity must be checked to determine whether the reinforcement is appropriate; To meet the anti-floating requirements, anti-floating calculations should be carried out during the construction period and the operation period after the bottom is sealed to determine whether the thickness of the caisson wall is appropriate.

8. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 2, the connection method of the segments is that a number of mortise and tenon grooves are pre-buried on both sides of the annular segments, and double elastic sealing pads are added in the horizontal mortise and tenon grooves for waterproofing. During the installation process, the horizontal connection holes temporarily serve as lifting holes for lifting installation.

9. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 2, the blade foot cushion layer concrete is poured in advance on site and then the blade foot ring segments are installed; in order to ensure the overall strength of the caisson during the construction process, a reinforcement ring caisson is spliced ​​on the blade foot ring, and a double-channel elastic sealing pad is also added to the plane of the caisson ring for waterproofing.

10. The construction method of the assembled circular caisson according to claim 1 is characterized in that: In step 2, two adjacent ring segments are longitudinally connected by a plurality of high-strength bolt connectors; the two ends of the connectors are respectively buckled into the corresponding grooves of the two adjacent ring segments, and the adjacent ring segments are also connected by high-strength threaded bolts.

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