Fabricated storage tank dome structure and construction method

Abstract

The invention discloses an assembly type storage tank dome structure and a construction method, and relates to the technical field of oil and gas storage facilities, in particular to the construction method of the assembly type storage tank dome structure, which comprises the following steps of: 1, adjusting a curve equation of a dome from an arc curve to a reasonable arch axis according to the span and the rise of the dome of a storage tank, the stress state on any section is close to a pure pressure state which is only subjected to axial pressure; and 2, reasonably arranging a dome bottom steel framework according to the reasonable arch axis so as to split the upper concrete dome. The storage tank dome is provided with a reasonable arch axis, and the stress state is theoretically a pure pressure state only bearing axial pressure; considering that various unavoidable errors occur in the implementation process, the actual stress state of the dome is very close to a pure pressure state. All components of the dome steel framework can also be precisely machined in a factory and then assembled on site; connection nodes of all the components can be welded connection and bolt connection.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas storage facilities, and particularly to a prefabricated storage tank dome structure and a construction method thereof. Background Art

[0002] LNG, that is, liquefied natural gas, liquefies gaseous natural gas through low temperature, and its storage requires special large storage tanks. Large prestressed concrete LNG storage tanks, with a storage capacity of more than 100,000 cubic meters, mainly consist of an inner tank and an outer tank; the inner tank is a steel tank for directly storing LNG; the outer tank is a monolithic cast-in-place prestressed reinforced concrete structure, including wall panels, a dome and a bottom plate, and its bottom plate also serves as the pile cap at the lower part of the storage tank, as Figure 1 shown. The main function of the outer tank is to protect the inner tank, store the gas in the interlayer between the inner and outer tanks, and store the leaked liquid under leakage conditions. Large prestressed concrete LNG storage tanks are as Figure 1 shown.

[0003] For existing large prestressed concrete storage tanks, their domes generally adopt spherical surfaces, and the cross-sectional stress state at any point on the dome coexists with axial force, bending moment and shear force, and the stress state is complex. The construction method of the dome is on-site integral casting; during the construction process of the dome, first, line setting, measurement and positioning are required, and then formwork support is carried out. Since the dome is a spherical surface, it is very difficult to shape and fix the formwork, and it is difficult to ensure the accuracy; a large amount of aerial work is required for steel bar arrangement, binding, formwork support, concrete pouring, etc., and it is difficult to ensure the construction accuracy and personnel safety. In addition, cast-in-place reinforced concrete requires a certain curing period and curing conditions, which prolongs the project cycle. Finally, the prefabricated construction of the dome is energy-saving and environmentally friendly, and conforms to the national policy of vigorously promoting the development of prefabricated buildings. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a prefabricated storage tank dome structure and a construction method thereof, which solve the problems put forward in the above background art.

[0006] (2) Technical Solutions

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions: A construction method for a prefabricated storage tank dome structure includes the following steps:

[0008] Step 1: According to the span and rise of the storage tank dome, adjust the curve equation of the dome from an arc curve to a reasonable arch axis, so that the stress state on any cross-section is close to a pure compression state only under axial compression;

[0009] Step 2: Reasonably arrange the steel skeleton at the bottom of the dome according to the reasonable arch axis to facilitate the disassembly of the upper concrete dome;

[0010] Step 3: Split the upper concrete dome according to the steel skeleton layout plan;

[0011] Step 4: Prefabricate the steel skeleton members in the factory according to the reasonable arch axis equation;

[0012] Step 5: According to the splitting plan and the block size, prefabricate the segmental plates and reinforced concrete in the factory according to the reasonable arch axis equation; stud bolts are set on the segmental plates to ensure reliable connection between the concrete and the segmental plates, forming precast plates; extension segmental plates and steel bar heads are reserved around the precast plates for convenient joint connection;

[0013] Step 6: After the steel skeleton is in place, weld and fix the steel skeleton to the bearing ring on the dome strengthening beam;

[0014] Step 7: In accordance with the symmetrical construction sequence, hoist and place the precast plates on the same arch axis in turn, leaving good connection gaps;

[0015] Step 8: Full penetration butt weld the reserved extension segmental plates at the bottom of each placed precast plate; connect the reserved extension steel bar heads of the precast plates to each other through additional longitudinal bars at the gaps;

[0016] Step 9: Pour and connect the gaps between the precast plates with a higher grade of slightly expanding concrete, and cure it under standard curing conditions until it reaches the design strength to form an integral body, so that this arch axis has load-bearing capacity;

[0017] Step 10: Repeat construction steps 7 to 9, and sequentially complete the assembly construction of the precast plates on all arch axes according to symmetry, so that the dome structure of the storage tank forms an integral body.

[0018] Optionally, in the above step 1, according to the span and rise of the storage tank dome, determine the relationship between the dome span and the dome rise, establish a mechanical model of the storage tank dome, and the reasonable arch axis equation is: In the formula: f is the rise of the dome, and l is the span of the dome.

[0019] Optionally, assume that the dome section equation is y = f(x), and there is a uniformly distributed load q acting on it. According to the knowledge of structural mechanics, the internal force at any point (x, y) on the dome section is:

[0020] Bending moment: M(x) = M 0 (x) - F H y(1)

[0021] Shearing force:

[0022] Axial force:

[0023] In the formula,

[0024] Optimize the dome cross-section curve equation to find the optimal curve equation, so that the bending moment at any point on the dome is 0, and then the dome is only subjected to axial force, giving full play to the compressive performance of the concrete material;

[0025] Let: Obtain:

[0026] Substitute Equation (5) into Equations (2) and (3), and the shear force and axial force at any point (x, y) on the dome of the optimal curve equation can be obtained as follows:

[0027]

[0028]

[0029]

[0030]

[0031] In fact, is the reasonable arch axis of a two-foot arch with a span of l and a rise of f; it can be seen from Equations (6) and (9) that when the dome curve equation adopts the reasonable arch axis, the bending moment and shear force on any cross-section of the dome are both 0, and only axial force acts;

[0032] To sum up, when the dome span l and rise f are both fixed values, its optimal curve equation is unique, that is Essentially, it is the reasonable arch axis equation of a two-foot arch; at any point on the dome of the optimal curve equation, the bending moment and shear force are both 0, and it is only subjected to axial compression, and the dome reaches the best stress state, and no tensile stress will be generated on the entire cross-section, and the concrete on the inner and outer surfaces of the dome will not be cracked due to tension.

[0033] Optionally, the magnitudes of the axial forces at the center and ends of the dome are shown in Equations (10) and (11) respectively:

[0034] When

[0035] When x = 0 and x = l,

[0036] Optionally, in the above step three, after the overall splitting of the upper concrete dome is completed, further reasonable splitting is carried out on the petal plates and the concrete dome in the upper concrete dome.

[0037] An assembled storage tank dome structure, the overall shape of the assembled storage tank dome structure is a paraboloid, which is assembled and combined by a steel framework at the bottom and an upper concrete dome. The upper concrete dome is laid above the steel framework; the steel framework is composed of a plurality of circumferential beams and a plurality of radial beams. The number of radial beams is an even number, and each radial beam is arranged annularly on the circumferential beam, and each radial beam and each circumferential beam are fixedly connected by combined assembly; the upper concrete dome is formed by assembling and fixedly connecting each precast slab; the precast slab is composed of a segmental plate and a concrete dome, and the concrete dome is cast on the segmental plate and the two are fixedly connected.

[0038] Optionally, outstretched segmental plates and outstretched steel bar heads are reserved on the peripheral sides of the precast slab. The precast slab is laid above the space between two adjacent radial beams and two adjacent circumferential beams, and the precast slab is fixedly connected to the radial beam and the circumferential beam located below it; the outstretched segmental plates of two adjacent precast slabs are abutted against each other, and are fixedly connected by welding at the abutting position; the outstretched steel bar heads of two adjacent precast slabs are fixedly connected by additional longitudinal bars.

[0039] Optionally, concrete is poured into the gap between two adjacent precast slabs, so that the connection between adjacent precast slabs is more firm by pouring concrete into the gap.

[0040] (III) Beneficial effects

[0041] The present invention provides an assembled storage tank dome structure and a construction method, which have the following beneficial effects:

[0042] 1. Adjust the curve equation of the dome from an arc curve to a reasonable arch axis, so that the stress state on any cross-section is close to a pure compression state only under axial compression, thereby making the splitting and prefabrication of the dome not restricted and affected by the sectional bending moment and shear force, and also ensuring the safety of the precast slab connection nodes, thus ensuring the safety of the storage tank dome.

[0043] 2. According to the steel skeleton layout scheme at the bottom of the entire storage tank dome, split the entire storage tank dome into small upper concrete dome blocks of multiple specifications (the upper concrete dome is split into individual parts), prefabricate the upper concrete dome individuals in the factory, that is, make precast slabs, and then transport the precast slabs to the construction site for hoisting and complete the node connection. By adopting an assembled construction method, the production accuracy and construction accuracy of each component of the storage tank dome are relatively high, the construction difficulty is low, the construction period is short, and it is energy-saving and environmentally friendly. Description of the drawings

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0045] Figure 1 It is a schematic cross-sectional structure diagram of the outer tank of the LNG storage tank;

[0046] Figure 2 It is a mechanical model diagram of a construction method for an assembled storage tank dome structure of the present invention;

[0047] Figure 3 It is a schematic structural diagram of the steel framework of an assembled storage tank dome structure of the present invention;

[0048] Figure 4 It is a schematic cross-sectional structure diagram of the steel framework of an assembled storage tank dome structure of the present invention;

[0049] Figure 5 It is Figure 4 a schematic connection structure diagram of node I in

[0050] Figure 6 It is Figure 4 a schematic connection structure diagram of nodes II, III, IV, V, VI, VII in

[0051] Figure 7 It is Figure 4 a schematic connection structure diagram of node X in

[0052] Figure 8 It is Figure 7 a sectional view along A-A in

[0053] Figure 9 It is a schematic diagram of the splitting of the segment plate and the concrete dome of an assembled storage tank dome structure of the present invention;

[0054] Figure 10 It is a schematic structural diagram of an assembled storage tank dome structure of the present invention for precast slabs (such as precast slab one, precast slab two, etc.);

[0055] Figure 11 It is a schematic structural diagram of an assembled storage tank dome structure of the present invention for a precast slab (such as precast slab six);

[0056] Figure 12 It is a schematic cross-sectional structure diagram of a single precast slab in an assembled storage tank dome structure of the present invention (i.e., Figure 14 sectional view along B-B in Figure 14 sectional view along C-C in Figure 15Cross-section view D-D);

[0057] Figure 13 Schematic diagram of the connection structure of the precast slab at node XI of the dome structure of an assembled storage tank according to the present invention;

[0058] Figure 14 is Figure 13 Cross-section view E-E in;

[0059] Figure 15 Schematic diagram of the connection structure between the dome structure of an assembled storage tank and the strengthening beam according to the present invention;

[0060] Figure 16 Mechanical analysis diagram of the construction method of the dome structure of an assembled storage tank according to the present invention;

[0061] Figure 17 Optimal curve dome axial force distribution diagram of the construction method of the dome structure of an assembled storage tank according to the present invention.

[0062] In the figure: 1, radial beam one; 2, radial beam two; 3, radial beam three; 4, circumferential beam one; 5, circumferential beam two; 6, circumferential beam three; 7, circumferential beam four; 8, circumferential beam five; 9, circumferential beam six; 10, seamless steel pipe; 11, plate one; 12, plate two; 13, upper ring plate; 14, cylinder; 15, lower ring plate; 23, precast slab one; 24, precast slab two; 25, precast slab three; 26, precast slab four; 27, precast slab five; 28, precast slab six; 29, reinforced concrete; 30, segmental plate; 31, stud; 32, extended reinforcing bar head; 33, additional longitudinal reinforcement; 34, cast-in-place material; 35, reserved reinforcing bar head of the strengthening beam; 36, dome strengthening beam; 37, bearing ring. Specific embodiments

[0063] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0064] Please refer to Figures 1 to 17 , the present invention provides a technical solution: an assembled storage tank dome structure, the assembled storage tank dome structure is a paraboloid as a whole, and is assembled and combined by a steel framework at the bottom and an upper concrete dome, and the upper concrete dome is laid above the steel framework. Among them, the cross-section of the steel framework is arched, conforming to the reasonable arch axis, and the stress state on any cross-section is close to the pure compression state only subjected to axial pressure. For its mechanical model, please refer to Figure 2 .

[0065] The steel framework is composed of multiple circumferential beams and multiple radial beams. The number of radial beams is an even number. Each radial beam is arranged in a ring on the circumferential beams, and each radial beam and each circumferential beam are fixedly connected through combined assembly.

[0066] Among them, for the connection and structural composition of the steel framework, please refer to Figures 3 to 8 . The fixed connection points between each circumferential beam and each radial beam form each node. Nodes refer to Node I, Node II, Node III, Node IV, Node V, Node VI, Node VII, Node VIII, Node X, Node IX, etc. Radial beams refer to Radial Beam 1, Radial Beam 2, Radial Beam 3, etc. Circumferential beams refer to Circumferential Beam 1, Circumferential Beam 2, Circumferential Beam 3, Circumferential Beam 4, Circumferential Beam 5, Circumferential Beam 6, etc. For the structure at each node of the steel framework, please refer to Figures 3 to 8 . At Node I, the circumferential beam includes an upper ring plate 13 and a lower ring plate 15. One end of Radial Beam 3 is fixedly connected to the upper ring plate 13 and the lower ring plate 15 of the circumferential beam through Plate 2 12. One end of Radial Beam 3 is fixedly connected to the seamless steel pipe 10 through Plate 1 11. A cylinder 14 is arranged on the circumferential beam.

[0067] The upper concrete dome is formed by assembling and fixedly connecting each precast slab; the precast slab is composed of a segmental plate and a concrete dome. The concrete dome is cast on the segmental plate and the two are fixedly connected.

[0068] Among them, precast slabs refer to Precast Slab 1 23, Precast Slab 2 24, Precast Slab 3 25, Precast Slab 4 26, Precast Slab 5 27, Precast Slab 6 28, etc. The concrete dome is composed of building components such as reinforced concrete. Multiple stud bolts 31 are arranged on the upper surface of the segmental plate 30. When manufacturing a single precast slab, the steel bars in the concrete dome are tied to each stud bolt 31, and the concrete is cast on the upper surface of the segmental plate 30. By casting the concrete at the positions of the steel bars and stud bolts, the segmental plate 30 and the solidified concrete are firmly connected together.

[0069] Specifically, the outer side wall of the precast slab is reserved with an extended segmental plate and extended steel bar heads. The precast slab is laid above the space between two adjacent radial beams and two adjacent circumferential beams, and the precast slab is fixedly connected to the radial beam and circumferential beam located below it; the extended segmental plates of two adjacent precast slabs are in contact with each other, and are welded and fixed at the contact position; the extended steel bar heads of two adjacent precast slabs are fixedly connected through additional longitudinal bars. Concrete is poured into the gap between two adjacent precast slabs, and by pouring the concrete into the gap, the connection between two adjacent precast slabs is made more firm.

[0070] A construction method for an assembled storage tank dome structure includes the following steps:

[0071] Step 1: According to the span and rise of the storage tank dome, adjust the curve equation of the dome from an arc curve to a reasonable arch axis, so that the stress state on any cross-section is close to a pure compression state where only axial compression is applied. In specific implementation, conduct a survey of the storage tank construction site, measure the span and rise of the storage tank dome, and establish a mechanical model of the dome based on the span and rise of the dome.

[0072] More specifically, determine the relationship between the span and rise of the dome according to the span and rise of the storage tank dome, establish a mechanical model of the storage tank dome, and the reasonable arch axis equation is: In the formula: f is the rise of the dome, and l is the span of the dome.

[0073] Even more specifically, please refer to Figure 2 、 Figure 16 、 Figure 17 , assuming that the dome cross-section equation is y = f(x), and there is a uniformly distributed load q acting on it. According to the knowledge of structural mechanics, the internal force at any point (x, y) on the dome cross-section is:

[0074] Bending moment: M(x) = M 0 (x) - F H y(1)

[0075] Shear force:

[0076] Axial force:

[0077] In the formula,

[0078] Optimize the dome cross-section curve equation to find the optimal curve equation, so that the bending moment at any point on the dome is 0, and further make the dome only subjected to axial force, giving full play to the compressive performance of the concrete material.

[0079] Let: We get:

[0080] Substitute Equation (5) into Equation (2) and Equation (3), and the shear force and axial force at any point (x, y) on the dome of the optimal curve equation can be obtained as follows:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] In fact, is the reasonable arch axis of a two-foot arch with a span of l and a rise of f. It can be seen from equations (6) and (9) that when the dome curve equation adopts the reasonable arch axis, the bending moment and shear force on any cross-section of the dome are both 0, and only axial force acts.

[0087] To sum up, when the dome span l and rise f are both fixed values, its optimal curve equation is unique, that is Essentially, it is the reasonable arch axis equation of a two-foot arch. At any point on the dome of the optimal curve equation, the bending moment and shear force are both 0, and it is only subjected to axial compression. The dome reaches the best stress state, no tensile stress will be generated on the entire cross-section, the concrete on the inner and outer surfaces of the dome will not be cracked due to tension, which can not only give full play to the compressive properties of concrete and steel bars, but also protect the steel bars inside the concrete well, and can also save the amount of concrete and steel bars, reducing costs. The magnitudes of the axial forces at the center and ends of the dome are shown in equations (10) and (11) respectively, and the axial force distribution on the entire cross-section is as Figure 17 shown.

[0088] When

[0089] x = 0 and x = l,

[0090] Step 2: Reasonably arrange the steel skeleton at the bottom of the dome according to the reasonable arch axis to facilitate the splitting of the upper concrete dome. In specific implementation, arrange the steel frame at the bottom of the dome according to the dome mechanical model in Step 1, so that the overall structure of the steel frame conforms to the reasonable arch axis, that is, the overall stress principle of the steel frame conforms to the reasonable arch axis equation:

[0091] Step 3: Split the upper concrete dome according to the steel skeleton layout plan.

[0092] Among them, split the upper concrete dome according to the reasonable arch axis and the layout of the steel frame (the splitting here refers to the model splitting). The upper concrete dome is split into multiple parts, and each part has corresponding specifications and dimensions to adapt to the layout of the steel frame, and the upper concrete dome also conforms to the stress condition of the reasonable arch axis. (Steps 1, 2, and 3 are all the theoretical preparation stages for the construction of the storage tank dome, including surveying and mapping, drawing design, etc.)

[0093] Step 4: Prefabricate the steel skeleton components in the factory according to the reasonable arch axis equation.

[0094] Among them, the steel skeleton is composed of various steel skeleton components, and the steel skeleton components can refer to various radial beams, various circumferential beams, etc.

[0095] Step Five: According to the splitting scheme and the block size, prefabricate the segmental plates and the reinforced concrete 29 in the factory according to the reasonable arch axis equation. Multiple stud bolts 31 are arranged on the segmental plates to enable reliable connection between the concrete and the segmental plates, forming precast slabs; extension segmental plates and steel bar heads are reserved around the precast slabs for facilitating joint connection.

[0096] Among them, multiple stud bolts 31 are arranged on the upper surface of the segmental plate 30. When fabricating a single precast slab, bind the steel bars to each stud bolt 31, pour the concrete on the upper surface of the segmental plate 30, and through the concrete pouring at the positions of the steel bars and the stud bolts, tightly connect the segmental plate 30 with the solidified concrete together, thereby realizing the integral fabrication of a single precast slab.

[0097] Step Six: After the steel framework is in place, weld and fix the steel framework to the bearing ring on the dome strengthening beam 36.

[0098] Among them, please refer to Figure 15 , the dome strengthening beam 36 includes a bearing ring 37 and a reserved steel bar head 35 for the strengthening beam. The ends of each radial beam (including the radial beam two 2) on the steel framework are welded to the bearing ring 37 on the dome strengthening beam 36. The extended steel bar heads 32 and the extended segmental plates of each precast slab located at the outermost ring of the dome are welded to the dome strengthening beam 36. Specifically, the extended steel bar heads 32 of each precast slab located at the outermost ring of the dome are welded to the reserved steel bar head 35 for the strengthening beam.

[0099] Step Seven: In accordance with the symmetrical construction sequence, hoist and place in position the precast slabs on the same arch axis in turn (the precast slabs are hoisted onto the steel framework and the precast slabs are assembled with the steel framework), and leave connection gaps between each precast slab.

[0100] Step Eight: Carry out full penetration butt welding on the reserved extended segmental plates at the bottom of each placed precast slab; connect the reserved extended steel bar heads 32 of the precast slabs to each other through additional longitudinal bars 33 at the gaps.

[0101] Among them, the extended parts of the segmental plates at the bottom of adjacent precast slabs are fully penetrated and welded, so that adjacent precast slabs are welded and fixed through the segmental plate 30. The reserved extended steel bar heads 32 of adjacent precast slabs are tied through additional longitudinal bars 33 at the gaps.

[0102] Step Nine: Pour and connect the gaps between each precast slab with a micro-expansion concrete of a higher grade (the freshly poured material 34), and cure under standard curing conditions until the design strength is reached to form an integral body, so that this arch axis has the load-bearing capacity.

[0103] Step Ten: Repeat construction steps Seven to Nine, and sequentially complete the assembly construction of the precast slabs on all arch axes according to symmetry, so that the dome structure of the storage tank forms an integral body.

[0104] The assembled storage tank dome structure and construction method of the present invention have a reasonable arch axis, and the stress state is theoretically a pure compression state only under axial pressure; considering various inevitable errors in the implementation process, the actual stress state of the dome is very close to the pure compression state. Each component of the dome steel skeleton can also be accurately processed in the factory and then assembled on site; the connection nodes of each component can be welded connections or bolt connections. The layout scheme of the dome steel skeleton, that is, the spacing of the radial and circumferential beams can be adjusted appropriately, and the size of the precast reinforced concrete slab can also be adjusted appropriately. The embedded parts of the attached structures at the top of the reinforced concrete dome can be prefabricated into the precast slab in the factory in advance according to the positions marked on the design drawings.

[0105] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A construction method for an assembled storage tank dome structure, characterized in that: It includes the following steps: Step 1: According to the span and rise of the storage tank dome, adjust the curve equation of the dome from an arc curve to a reasonable arch axis, so that the stress state on any cross-section is close to a pure compression state only subjected to axial pressure; Step 2: Reasonably arrange the steel skeleton at the bottom of the dome according to the reasonable arch axis to facilitate the splitting of the upper concrete dome; Step 3: Split the upper concrete dome according to the steel skeleton layout plan; Step 4: Prefabricate the steel skeleton members in the factory according to the reasonable arch axis equation; Step 5: According to the splitting plan and block size, prefabricate the segmental plates and reinforced concrete in the factory according to the reasonable arch axis equation; stud bolts are arranged on the segmental plates to reliably connect the concrete and the segmental plates to form precast plates; extension segmental plates and steel bar heads are reserved around the precast plates for facilitating node connection; Step 6: After the steel skeleton is in place, weld and fix the steel skeleton to the bearing ring on the dome strengthening beam; Step 7: In accordance with the symmetric construction sequence, hoist and place in position the precast plates on the same arch axis in turn, leaving connection gaps; Step 8: Full penetration butt weld the reserved extension segmental plates at the bottom of each placed precast plate; connect the reserved extension steel bar heads of the precast plates to each other through additional longitudinal bars at the gaps; Step 9: Pour and connect the gaps of the precast plates with a micro-expansion concrete of a higher grade, and cure under standard curing conditions until the design strength to form an integral body, so that this arch axis has load-bearing capacity; Step 10: Repeat construction steps 7 to 9, and successively complete the assembly construction of the precast plates on all arch axes in accordance with symmetry, so that the storage tank dome structure forms an integral body.

2. A construction method for an assembled storage tank dome structure according to claim 1, characterized in that: In the first step above, according to the span and rise of the storage tank dome, the relationship between the dome span and the dome rise is determined, a mechanical model of the storage tank dome is established, and the reasonable arch axis equation is: Where: f is the rise of the dome, and l is the span of the dome.

3. A construction method for an assembled storage tank dome structure according to claim 2, characterized in that: Assume that the dome cross-section equation is y = f(x), and a uniform load q acts on it. According to the knowledge of structural mechanics, the internal force at any point (x, y) on the dome cross-section is: Bending moment: M(x) = M 0 (x) - F H y(1) Shearing force: Axial force: Wherein, Optimize the dome cross-section curve equation to seek the optimal curve equation, so that the bending moment at any point on the dome is 0, and further make the dome only subjected to axial force, giving full play to the compressive performance of the concrete material; Let: Obtained: Substitute Equation (5) into Equations (2) and (3), and the shear force and axial force at any point (x, y) on the dome of the optimal curve equation can be obtained as follows: In fact, is the reasonable arch axis of a two-hinged arch with a span of l and a rise of f; it can be seen from equations (6) and (9) that when the dome curve equation adopts the reasonable arch axis, the bending moment and shear force on any section of the dome are both 0, and only axial force acts; In summary, when the dome span \(l\) and rise \(f\) are both fixed values, the optimal curve equation is unique, that is essentially the reasonable arch axis equation of a two-hinged arch; at any point on the dome of the optimal curve equation, the bending moment and shear force are both 0, and it is only under axial compression. The dome reaches the best stress state, no tensile stress will be generated on the entire cross-section, and the concrete on the inner and outer surfaces of the dome will not be cracked due to tension.

4. A construction method for an assembled storage tank dome structure according to claim 3, characterized in that: The magnitudes of the axial forces at the dome center and ends are shown in Equations (10) and (11) respectively: When when x = 0 and x = l 5. A construction method for an assembled storage tank dome structure according to claim 1, characterized in that: In the above step 3, after the overall splitting of the upper concrete dome is completed, further reasonably split the segmental plates and the concrete dome in the upper concrete dome.

6. An assembled storage tank dome structure, characterized in that: The overall assembled storage tank dome structure is a paraboloid, which is assembled and combined by a steel framework at the bottom and an upper concrete dome. The upper concrete dome is laid above the steel framework. The steel framework is composed of a plurality of circumferential beams and a plurality of radial beams. The number of radial beams is an even number. Each radial beam is arranged annularly on the circumferential beam, and each radial beam is fixedly connected to each circumferential beam through combined assembly. The upper concrete dome is formed by fixedly connecting each precast slab after assembly; the precast slab is composed of a segmental plate and a concrete dome. The concrete dome is poured on the segmental plate and the two are fixedly connected.

7. An assembled storage tank dome structure according to claim 6, characterized in that: Outrigger segmental plates and outrigger steel bar heads are reserved on the peripheral sides of the precast slab. The precast slab is laid above the space between two adjacent radial beams and two adjacent circumferential beams, and the precast slab is fixedly connected to the radial beam and the circumferential beam located below it; the outrigger segmental plates of two adjacent precast slabs are in contact with each other, and are fixedly connected by welding at the contact position; the outrigger steel bar heads of two adjacent precast slabs are fixedly connected through additional longitudinal bars.

8. An assembled storage tank dome structure according to claim 7, characterized in that: Concrete is poured into the gap between two adjacent precast slabs, so that the connection between adjacent precast slabs is made more firm by pouring concrete into the gap.

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