Prestress calculation method and device for prestressed concrete containment with non-bonded prestressed reinforcement

Abstract

The application discloses a prestress calculation method and device for a non-bonded prestressed concrete containment reinforcement, and the method comprises the following steps: obtaining a first total deformation of a single non-bonded steel strand under a preset single load; obtaining a first unit stress variable of the non-bonded steel strand according to the first total deformation and an elastic modulus of the steel strand; obtaining a first compensation stress load required for a bonded steel strand to be converted into the non-bonded steel strand according to the first unit stress variable and a second unit stress variable of the bonded steel strand; and determining a first prestress of the non-bonded steel strand under the preset single load according to a second prestress of the bonded steel strand under the preset single load and the first compensation stress load. The application can more accurately determine the first prestress of the steel strand under the preset single load, thereby providing support for subsequent stress calculation of concrete in a load combination condition in the design of a non-bonded prestressed concrete containment.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power technology, specifically relating to a method, apparatus, and containment for calculating the prestress of unbonded prestressed concrete containment reinforcement. Background Technology

[0002] A prestressed concrete containment shell consists of concrete and reinforcement (prestressing tendons). The prestressing tendons are multiple bundles, each containing multiple steel strands, used to provide prestress against accidental stress, without considering their load-bearing capacity contribution. The concrete bears the loads generated by the prestressing tendons and stress variations under load combinations. The combined use of both allows the prestressed concrete containment shell to exhibit better crack resistance and durability while bearing loads.

[0003] In the design process of prestressed concrete containment structures, the prestress changes of the reinforcement of the unbonded prestressed concrete containment structure under preset loads are first determined, and then the stress requirements of the concrete part are designed based on the prestress changes of the reinforcement of the unbonded prestressed concrete containment structure.

[0004] However, in existing technologies, the prestress variation of the reinforcement in unbonded prestressed concrete containment structures is replaced by the prestress of the reinforcement in bonded prestressed concrete containment structures. Since the deformation patterns of the reinforcement and concrete in unbonded prestressed concrete containment structures differ from those in bonded prestressed concrete containment structures, using the stress variation of bonded reinforcement to replace the stress variation of unbonded reinforcement results in lower accuracy of the prestress calculation for the reinforcement in unbonded prestressed concrete containment structures, thus reducing the accuracy of concrete stress calculations during the design process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art by providing a method, apparatus and system for calculating the prestress of reinforcement in unbonded prestressed concrete containment structures. Using this method, the deformation mode of reinforcement in unbonded prestressed concrete containment structures within the concrete shell can be accurately simulated, effectively improving the accuracy of prestress calculation for reinforcement in unbonded prestressed concrete containment structures.

[0006] In a first aspect, the present invention provides a method for calculating the prestress of reinforcement in unbonded prestressed concrete containment structures, comprising:

[0007] Obtain the first total deformation of a single unbonded steel strand under a preset single load;

[0008] Based on the first total deformation and the elastic modulus of the steel strand, the first unit stress variable of the unbonded steel strand is obtained;

[0009] Based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand, the first compensation stress load required to transform the bonded steel strand into an unbonded steel strand is obtained.

[0010] Based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load, the first prestress of the unbonded steel strand under the preset single load is determined.

[0011] In some embodiments, obtaining the total deformation of a single steel strand under a preset single load includes:

[0012] The second total deformation of a single bonded steel strand under a preset single load is defined as the first total deformation of a single unbonded steel strand under a preset single load, which specifically includes:

[0013] The second total deformation of the bonded steel strand under a preset single load is calculated according to the following formula (1):

[0014]

[0015] Where ΔL is the second total deformation (m) of a single bonded steel strand; L is the total length (m) of a single steel strand before the load is applied; E s σ is the elastic modulus of the steel strand (MPa); s is the distance (m) from the starting point of the steel strand to the finite element element; Δσ 有粘结 The stress variable (MPa) of the bonded prestressed steel strand under a preset single load is the second unit stress variable of the bonded steel strand.

[0016] The second total deformation is determined as the first total deformation of a single unbonded steel strand under a preset single load.

[0017] In some embodiments, calculating the first unit stress variable of the unbonded steel strand based on the first total deformation and the elastic modulus of the steel strand includes:

[0018] Assuming that the stress change of the entire unbonded steel strand is uniform under a preset single load, the stress variable of the first unit of the unbonded steel strand is calculated according to the following formula (2):

[0019] Δσ PE =ΔL / L×E s (2)

[0020] Where, Δσ PE Let be the first unit stress variable (MPa) of the unbonded prestressed steel strand, ΔL be the first total deformation (m) of a single unbonded steel strand, L be the total length (m) of a single unbonded steel strand before the load is applied, and E be the total stress variable (MPa) of the unbonded prestressed steel strand. sThe modulus of elasticity (MPa) of unbonded steel strand.

[0021] In some embodiments, calculating the first compensation stress load required for the bonded steel strand to transform into an unbonded steel strand based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand specifically includes:

[0022] The second compensating stress load required for the unbonded steel strand is calculated according to the following formula (3):

[0023] σ 补偿 =Δσ PE -Δσ 有粘结 (3)

[0024] Where, σ 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand;

[0025] The second compensating stress load is corrected according to the following formula (4) to obtain the first compensating stress load required for the conversion of bonded steel strands into unbonded steel strands, in order to compensate for the deviation caused by the elastic deformation of concrete:

[0026]

[0027] in, σ represents the first compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; A s The area of ​​each steel strand (m²) 2 );s p t is the distance between the steel strands (m); t is the thickness of the containment structure (m); E c This is the elastic modulus of concrete (MPa).

[0028] In some embodiments, determining the first prestress of the unbonded steel strand under the preset single load based on the second prestress of the bonded steel strand under the preset single load and the first compensating stress load includes:

[0029] Using finite element method (FEM) software, the second prestress of bonded steel strands in a bonded prestressed concrete containment structure under a preset single load was obtained, and...

[0030] Obtain the first compensating force of the bonded steel strands in the bonded prestressed concrete containment under the first compensating stress load;

[0031] The second prestress and the first compensating force are combined to obtain the first prestress of the unbonded steel strand in the unbonded prestressed concrete containment under a preset single load.

[0032] In some embodiments, the method further includes:

[0033] Based on the determined first prestress of the unbonded steel strand under a preset single load, calculate the first stress of the concrete in the unbonded prestressed concrete containment.

[0034] Secondly, the present invention also provides a prestress calculation device for the reinforcement of unbonded prestressed concrete containment structures, the device comprising:

[0035] The acquisition module is configured to acquire the first total deformation of a single unbonded steel strand under a preset single load.

[0036] The first obtaining module, connected to the acquisition module, is configured to obtain the first unit stress variable of the unbonded steel strand based on the first total deformation and the elastic modulus of the steel strand.

[0037] The second obtaining module is connected to the first obtaining module. It is set to obtain the first compensation stress load required for the bonded steel strand to be transformed into an unbonded steel strand based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand.

[0038] The determination module is connected to the second obtained module, which is set to determine the first prestress of the unbonded prestressed concrete containment shell reinforcement under the preset single load based on the second prestress and the first compensating stress load of the bonded prestressed concrete containment shell under the preset single load.

[0039] In some embodiments, the second obtaining module is further used for

[0040] The second compensating stress load required for the unbonded steel strand is calculated according to the following formula (3):

[0041] σ 补偿 =Δσ PE -Δσ 有粘结 (3)

[0042] Where, σ 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand;

[0043] The second compensating stress load is corrected according to the following formula (4) to obtain the first compensating stress load required for the conversion of bonded steel strands into unbonded steel strands, in order to compensate for the deviation caused by the elastic deformation of concrete:

[0044]

[0045] in, σ represents the first compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; A s The area of ​​each steel strand (m²) 2 );s p t is the distance between the steel strands (m); t is the thickness of the containment structure (m); E c This is the elastic modulus of concrete (MPa).

[0046] Thirdly, the present invention also provides a design apparatus for an unbonded prestressed concrete containment structure, comprising:

[0047] The prestress calculation device for the reinforcement of unbonded prestressed concrete containment as described in any of the preceding items is used to determine the first prestress of the unbonded steel strand under a preset single load.

[0048] The concrete design module, connected to the prestressing calculation device, is used to combine the first prestress and the preset single load to design the concrete in the unbonded prestressed concrete safety shell.

[0049] The containment design module, connected to the concrete design module, is used to design the containment based on the concrete.

[0050] Fourthly, the present invention also provides an unbonded prestressed concrete containment structure, comprising: concrete and steel strands composed of unbonded steel wires.

[0051] The unbonded prestressed concrete containment structure is designed using the aforementioned installation device.

[0052] The prestress calculation method for the reinforcement of unbonded prestressed concrete containment structures of the present invention obtains the first total deformation of a single unbonded steel strand, calculates the first unit stress variable of the unbonded steel strand, and calculates the first compensating stress load required for the conversion of bonded steel strands into unbonded steel strands. Because the first compensating stress load compensates for the incoordination between the unbonded steel strand and the concrete deformation, it can accurately simulate the stress change of the reinforcement within the concrete shell of the unbonded prestressed concrete containment structure. Therefore, it can more accurately determine the first prestress of the steel strand under a preset single load. This provides more accurate support for subsequent stress calculations of the concrete under load combinations in the design of unbonded prestressed concrete containment structures. Attached Figure Description

[0053] Figure 1A flowchart illustrating a prestress calculation method for the reinforcement of an unbonded prestressed concrete containment shell, provided as an embodiment of the present invention;

[0054] Figure 2 A flowchart illustrating an application embodiment of a prestress calculation method for the reinforcement of an unbonded prestressed concrete containment shell provided by an embodiment of the present invention;

[0055] Figure 3a and Figure 3b These are schematic diagrams showing the displacement of a bonded and unbonded prestressed concrete containment shell under accident pressure load, respectively, according to embodiments of the present invention.

[0056] Figure 4a and Figure 4b These are stress diagrams of prestressed tendons in a bonded and unbonded prestressed concrete containment shell provided in embodiments of the present invention.

[0057] Figure 5 A schematic diagram of the stress in the steel strands of a typical inverted U-shaped prestressed tendon in a bonded and unbonded prestressed containment structure provided in this embodiment of the invention;

[0058] Figure 6 A schematic diagram of the stress of a typical horizontal prestressed steel strand in a bonded and unbonded prestressed containment structure provided for an embodiment of the present invention;

[0059] Figure 7 A schematic diagram of the stress of a typical horizontal prestressed steel strand in a dome of a bonded and unbonded prestressed containment structure provided in this embodiment of the invention;

[0060] Figure 8 This is a structural diagram of a prestressing calculation device for unbonded prestressed concrete containment reinforcement, provided in an embodiment of the present invention. Detailed Implementation

[0061] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0063] In related technologies, ANSYS software struggles to simulate unbonded reinforcement. Therefore, the prestress calculation for unbonded prestressed concrete containment structures often uses the prestress of bonded prestressed concrete containment structures as an approximation. However, in bonded prestressed concrete containment structures, the steel strands deform in coordination with the concrete; while in unbonded prestressed concrete containment structures, the steel strands can still slide within the containment structure after concrete pouring, resulting in inconsistent deformation with the concrete. Under load, the internal stress of the reinforcement redistributes due to this sliding. In other words, the deformation patterns of reinforcement and concrete in unbonded prestressed concrete containment structures differ from those in bonded prestressed concrete containment structures. Therefore, using the stress changes of bonded reinforcement to replace the stress changes of unbonded reinforcement leads to lower accuracy in the prestress calculation of unbonded prestressed concrete containment structures, thus reducing the accuracy of concrete stress calculations during the design process.

[0064] Unlike bonded prestressed concrete containment structures, the prestress in unbonded prestressed concrete containment structures does not change in tandem with the deformation of the containment structure under a preset load. Instead, it is redistributed as the prestressing tendons slide inside. Therefore, accurately simulating the changes in unbonded prestress can improve the accuracy of concrete stress calculations during the design of unbonded prestressed concrete containment structures.

[0065] The inventors discovered that by first analyzing a single load on the reinforcement in bonded prestressed concrete, the total deformation of the steel strands is determined. Then, unbonded steel strands are allowed to slide freely along their length. Under a preset single load, the stress change throughout the entire steel strand is uniform, thus obtaining the element stress variable for each unbonded steel strand. Finally, the element stress variable of each steel strand is subtracted from the initial calculated stress variable of each finite element element for that strand to obtain the compensated stress variable for each finite element element of the unbonded steel strand. This compensated stress variable is applied as a load case to the bonded prestressed concrete model, accurately simulating the stress changes of the reinforcement within the concrete shell of unbonded prestressed concrete. This method overcomes the problem of incompatible deformation between the steel strands and concrete in unbonded prestressed concrete, making the prestress calculation of the reinforcement in unbonded prestressed concrete containment structures more accurate.

[0066] Based on this, in order to solve the problems of the prior art, the present invention proposes a method and apparatus for calculating the prestress of the reinforcement of unbonded prestressed concrete containment shells, which can accurately simulate the stress changes of the reinforcement in the concrete shell of unbonded prestressed concrete containment shells and improve the accuracy of the prestress calculation of the reinforcement of unbonded prestressed concrete containment shells.

[0067] Example 1:

[0068] like Figure 1 As shown, this embodiment provides a prestress calculation method for the reinforcement of unbonded prestressed concrete containment structures, mainly used in the design of containment structures in nuclear power systems, including steps S1 to S4:

[0069] Step S1. Obtain the first total deformation of a single unbonded steel strand under a preset single load.

[0070] Here, the preset single load can refer to the accident pressure load or other loads. In some implementations, the accident pressure load can be set according to the containment configuration to ensure that the containment can maintain its integrity and prevent radioactive materials from leaking into the environment under extreme conditions.

[0071] Unbonded steel strands can be PE (Polyethylene) unbonded steel strands. These strands are externally sheathed with a PE sheath and internally filled with anti-corrosion lubricating grease. They have a relatively low coefficient of friction, allowing for higher effective prestress. When applied to the prestressing system of nuclear power plant containment vessels, this can reduce the amount of prestressing material used and save construction time. It should be noted that unbonded steel strands can also be designed in other ways, and this application does not limit this approach.

[0072] During implementation, the first total deformation of a single unbonded steel strand under a preset single load is obtained, which can be specifically obtained based on the total deformation of a single bonded steel strand in bonded prestressed concrete. This is because, under a preset single load, the total deformation of the reinforcement in a bonded prestressed concrete containment structure is the same as that in an unbonded prestressed concrete containment structure.

[0073] like Figure 3a and Figure 3b As shown, the displacement of the unbonded prestressed concrete containment shell is very small compared with that of the bonded prestressed concrete containment shell. Therefore, it can be considered that under a preset single load, the total deformation of the reinforcement of the bonded prestressed concrete containment shell and the total deformation of the reinforcement of the unbonded prestressed concrete containment shell are the same.

[0074] Step S2. Based on the first total deformation and the elastic modulus of the steel strand, obtain the first unit stress variable of the unbonded steel strand.

[0075] Here, the elastic modulus of steel strand is an indicator of a material's ability to resist deformation within its elastic range. For high-strength prestressed steel strands, the elastic modulus is typically between 190 GPa and 210 GPa. In some implementations, the selection of the elastic modulus of the steel strand must also comply with the requirements of relevant national standards or industry specifications.

[0076] The stress variable of the first element is the stress variable of the finite element along the length of the steel strand, representing the first total deformation. It can be understood that in this embodiment, the unbonded steel strand slides freely along its length, and under a preset single load, the stress change of the entire steel strand is uniform.

[0077] like Figure 4a and Figure 4b As shown, under a pre-set single load (accident pressure load), the stress in each steel strand of the unbonded prestressed concrete containment shell is basically uniform.

[0078] In practice, the strain variables of the finite element of the unbonded steel strand can be determined by the first total deformation of a single unbonded steel strand and the total length of the single steel strand before the application of a preset single load; then, the first element stress variable of the unbonded steel strand can be obtained based on the strain variables of the finite element of the unbonded steel strand and the elastic modulus of the steel strand.

[0079] Step S3. Based on the stress variables of the first unit and the corresponding stress variables of the second unit of the bonded steel strand, obtain the first compensating stress load required to transform the bonded steel strand into an unbonded steel strand.

[0080] Here, existing prestressing calculation software for bonded prestressed concrete containment reinforcement can be used to perform finite element calculations to extract the second element stress variables of the bonded steel strands.

[0081] In practice, the stress variable of the bonded steel strand under the same preset single load can be subtracted from the stress variable of the first unit. The difference is the stress load that needs to be compensated for when the bonded steel strand is transformed into an unbonded steel strand.

[0082] In some implementations, the stress load that needs to be compensated for when converting bonded steel strands to unbonded steel strands can also be taken into account. When directly applied to the prestressing calculation model of the bonded prestressed concrete containment reinforcement, deviations will occur due to the elastic deformation of the concrete. Therefore, the stress load that needs to be compensated for when converting bonded steel strands to unbonded steel strands needs to be corrected to obtain the first compensating stress load.

[0083] Step S4. Determine the first prestress of the unbonded steel strand under the preset single load based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load.

[0084] Here, the second prestress characterizes the force exerted on the concrete by the bonded steel strands under a preset single load. In practice, the second prestress of the bonded steel strands under a preset single load can be obtained through finite element analysis using existing software for calculating the prestress of bonded prestressed concrete containment reinforcement.

[0085] The first prestress characterizes the force exerted by the unbonded steel strand on the concrete under a preset single load. During implementation, the second prestress exerted by the bonded steel strand on the concrete under the preset single load, and the compensating force exerted by the bonded steel strand on the concrete under the first compensating stress load, are combined to determine the first prestress of the unbonded steel strand under the preset single load.

[0086] Specifically, existing prestressing calculation software for bonded prestressed concrete containment structures can be used to simulate: the force exerted by the bonded steel strands on the concrete under a preset single load (second prestress), and the compensating force exerted by the bonded steel strands on the concrete under a first compensating stress load. By combining the force exerted by the bonded steel strands on the concrete and the compensating force, the force exerted by the unbonded steel strands on the concrete under a preset single load (first prestress) can be obtained using existing prestressing calculation software for bonded prestressed concrete containment structures.

[0087] In some other embodiments, the actual unit stress variables of the unbonded steel strand can be determined by superimposing the first compensating stress load of the corresponding unit on the second unit stress variables of each bonded steel strand in the existing prestress calculation software for bonded prestressed concrete containment structures; then, the first prestress of the unbonded steel strand under the action of a preset single load can be determined based on the actual unit stress variables of the unbonded steel strand.

[0088] In this embodiment, by obtaining the first total deformation of a single unbonded steel strand, calculating the first unit stress variable of the unbonded steel strand, and calculating the first compensating stress load required to transform the bonded steel strand into an unbonded steel strand, the first compensating stress load can accurately simulate the stress change of the reinforcement within the concrete shell in an unbonded prestressed concrete containment structure. This allows for a more accurate determination of the first prestress of the steel strand under a preset single load. Consequently, this provides more accurate support for subsequent stress calculations of the concrete under load combinations in the design of unbonded prestressed concrete containment structures.

[0089] In some embodiments, step S1 includes step S11:

[0090] Step S11. Determine the second total deformation of a single bonded steel strand under a preset single load as the first total deformation of a single unbonded steel strand under a preset single load, which specifically includes:

[0091] The second total deformation of the bonded steel strand under a preset single load is calculated according to the following formula (1):

[0092]

[0093] Where ΔL is the second total deformation (m) of a single bonded steel strand; L is the total length (m) of a single steel strand before the load is applied; E s σ is the elastic modulus of the steel strand (MPa); s is the distance (m) from the starting point of the steel strand to the finite element element; Δσ 有粘结 The stress variable (MPa) of the bonded prestressed steel strand under a preset single load is the second unit stress variable of the bonded steel strand.

[0094] The second total deformation is determined as the first total deformation of a single unbonded steel strand under a preset single load.

[0095] Understandably, for bonded steel strands (bonded prestressed concrete containment reinforcement) and unbonded steel strands (unbonded prestressed concrete containment reinforcement), under the same load, although the stress distribution of the steel strands is different, the total deformation of a single steel strand should be the same. Therefore, following the design method for bonded prestressed concrete containment reinforcement, a single load analysis is performed on the unbonded prestressed concrete containment reinforcement. The deformation of all finite element elements in each steel strand is extracted and summed to obtain the total deformation (second total deformation). This second total deformation is also the total deformation of the unbonded prestressed concrete containment reinforcement under the same single load (i.e., the first total deformation).

[0096] For example, according to the design method of reinforced prestressed concrete containment structure, by finite element extraction, for a steel strand length of 157.9284m, the length change of a single bonded steel strand under the action of accident pressure load is calculated to be 0.02718m according to formula (1). Therefore, the length change of a single unbonded steel strand under the action of accident pressure load is also 0.02718m.

[0097] In this embodiment, the total deformation of a single bonded steel strand under a preset single load is determined as the first total deformation of a single unbonded steel strand under a preset single load, thereby determining the total deformation of the unbonded prestressed concrete containment reinforcement under a preset single load, providing a basis for subsequent prestress calculation of the unbonded prestressed concrete containment reinforcement.

[0098] In some embodiments, step S2 specifically includes:

[0099] Assuming that the stress change of the entire unbonded steel strand is uniform under a preset single load, the stress variable of the first unit of the unbonded steel strand is calculated according to the following formula (2):

[0100] Δσ PE =ΔL / L×E s (2)

[0101] Where, Δσ PE Let be the first unit stress variable (MPa) of the unbonded prestressed steel strand, ΔL be the first total deformation (m) of a single unbonded steel strand, L be the total length (m) of a single unbonded steel strand before the load is applied, and E be the total stress variable (MPa) of the unbonded prestressed steel strand. s The modulus of elasticity (MPa) of unbonded steel strand.

[0102] Here, the strain variable of the finite element of the unbonded steel strand can be determined according to ΔL / L; then, by dividing the strain variable of the finite element by the elastic modulus of the steel strand, the stress variable of the finite element can be obtained, that is, the stress variable of the first element of the unbonded steel strand.

[0103] It should be noted that, under the preset single load, the stress change of the entire unbonded steel strand is uniform. This is because the unbonded steel strand can still slide freely along its length within the containment structure after the concrete is poured. Therefore, under the preset single load, the stress change (Δσ) of each finite element element is uniform. PE The stress is also uniform, so the stress variable of the first unit of the unbonded steel strand can be calculated according to the above formula (2).

[0104] In this embodiment, by setting the stress change of the entire unbonded steel strand to be uniform under a preset single load, the first unit stress variable of the unbonded steel strand can be calculated. This can simulate the uncoordinated deformation between the unbonded steel strand and the concrete, and more accurately simulate the stress change of the reinforcement in the unbonded prestressed concrete containment shell. This provides support for more accurately determining the first prestress of the steel strand under a preset single load.

[0105] In some embodiments, step S3 specifically includes steps S31 to S32:

[0106] Step S31. Calculate the second compensating stress load required for the unbonded steel strand according to the following formula (3):

[0107] σ 补偿 =Δσ PE -Δσ 有粘结 (3)

[0108] Where, σ 补偿 This is the second compensating stress load (MPa) required for the steel strand to be transformed from a bonded steel strand to an unbonded steel strand.

[0109] Here, the second compensating stress load is the stress load that each finite element needs to compensate for when it is transformed from a bonded steel strand to an unbonded steel strand.

[0110] Step S32. The second compensating stress load is corrected according to the following formula (4) to obtain the first compensating stress load required for the bonded steel strand to be transformed into an unbonded steel strand, so as to compensate for the deviation caused by the elastic deformation of the concrete:

[0111]

[0112] in, σ represents the first compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; A s The area of ​​each steel strand (m²)2 );s p t is the distance between the steel strands (m); t is the thickness of the containment structure (m); E c This is the elastic modulus of concrete (MPa).

[0113] Here, directly applying the second compensating stress load to the model for calculation will cause deviations due to the elastic deformation of concrete, so the second compensating stress load needs to be corrected.

[0114] The cross-sectional shape of prestressed steel strands can be approximately circular. The diameter and corresponding cross-sectional area of ​​standard prestressed steel strands can be determined according to specific product specifications. For example, commonly used prestressed steel strand diameters include 12.7 mm and 15.2 mm. For a standard prestressed steel strand with a diameter of 15.2 mm, its cross-sectional area is approximately 181 square millimeters.

[0115] The spacing between the steel strands refers to the arrangement interval of the prestressing tendons within the containment. The spacing of the steel strands in an unbonded prestressed concrete containment can be designed according to relevant design specifications in this field.

[0116] The thickness of the containment vessel is generally between tens of centimeters and one meter. The thickness of the containment vessel can be determined based on factors such as design standards, type of nuclear power plant, and geographical location.

[0117] The elastic modulus of concrete refers to a measure of its stiffness in the direction of stress. The elastic modulus of concrete can range from 20 GPa to 50 GPa. The specific value of the elastic modulus of concrete can be determined based on the containment design requirements.

[0118] In this embodiment, by calculating the second compensating stress load required for unbonded steel strands and determining the first compensating stress load required for converting bonded steel strands into unbonded steel strands, the deviation caused by the elastic deformation of concrete under a preset single load can be compensated. This facilitates a more accurate description of the prestressing of the reinforcement of unbonded prestressed concrete containment structures within existing bonded prestressed concrete containment structures.

[0119] In some embodiments, step S4 includes steps S41 to S42:

[0120] Step S41. Using finite element analysis software, obtain the second prestress of the bonded steel strands in the bonded prestressed concrete containment shell under a preset single load, and...

[0121] Obtain the first compensating force of the bonded steel strands in the bonded prestressed concrete containment under the first compensating stress load.

[0122] Here, the second prestress of the bonded steel strands in the bonded prestressed concrete containment shell under a preset single load can be obtained by applying a preset single load to the bonded prestressed concrete containment shell using existing prestress calculation software for bonded prestressed concrete containment shell reinforcement (e.g., finite element software). For example, the second prestress is the force composed of the stress variables of each second element.

[0123] The compensating force of the first compensating stress load on the concrete is determined by applying a first compensating stress load to the bonded prestressed concrete containment shell. For example, the first compensating force is the force constituted by each of the first compensating stress loads.

[0124] Step S42. Combine the second prestress and the first compensating force to obtain the first prestress of the unbonded steel strand in the unbonded prestressed concrete containment under a preset single load.

[0125] Here, in the finite element software, the second prestress and the first compensating force are combined to obtain the first prestress of the unbonded steel strand in the unbonded prestressed concrete containment under a preset single load.

[0126] For example, by post-processing the analysis results of a bonded prestressed containment structure, the first prestress of the unbonded prestressed steel strands under accident pressure load was found to be 10.95 MPa. Figure 5 As shown, the stress of the prestressed steel strands in the typical inverted U-shaped unbonded prestressed containment structure is basically uniform and very close to the theoretically calculated value of 10.95 MPa. This indicates that the prestress calculation of the unbonded prestressed concrete containment structure in this embodiment has high accuracy.

[0127] In this embodiment, by obtaining the second prestress of the bonded prestressed concrete containment shell under a preset single load, and by combining the second prestress and the first compensating stress load, a more accurate first prestress of the unbonded steel strands in the unbonded prestressed concrete containment shell under a preset single load can be obtained.

[0128] In some embodiments, the method further includes:

[0129] Based on the determined first prestress of the unbonded steel strand under a preset single load, calculate the first stress of the concrete in the unbonded prestressed concrete containment.

[0130] Here, the first stress can be the ultimate bearing capacity of the concrete or other stresses.

[0131] In existing bonded prestressed concrete containment systems, the first prestress of the unbonded steel strands under a preset single load is used to accurately simulate the force exerted by the reinforcement on the concrete in an unbonded prestressed concrete containment system. Specifically, in existing bonded prestressed concrete containment systems, a preset single load is applied to the concrete of the bonded prestressed concrete containment system to perform stress analysis, yielding the first analysis result. A first compensating load is then applied to the concrete of the bonded prestressed concrete containment system to perform stress analysis, yielding the second analysis result. The first and second analysis results are then combined to obtain the analysis result (i.e., the first stress) of the unbonded prestressed concrete containment system.

[0132] In some other embodiments, the first stress of the concrete in the unbonded prestressed concrete containment can be calculated by obtaining the second unit stress variables of the bonded steel strands and the first compensating stress load of the corresponding units in an existing bonded prestressed concrete containment system, determining the stress variables of each unit of the unbonded steel strands, and then applying the stress variables of each unit of the unbonded steel strands to the existing bonded prestressed concrete containment system to simulate and calculate the first stress of the concrete in the unbonded prestressed concrete containment.

[0133] In this embodiment, the first prestress is used to calculate the first stress of the concrete in the unbonded prestressed concrete containment shell. Because the first prestress has load compensation, the stress change of the reinforcement in the concrete shell of the unbonded prestressed concrete containment shell can be accurately simulated in the existing bonded prestressed concrete containment shell system, thereby improving the accuracy of the concrete stress calculation of the unbonded prestressed concrete containment shell.

[0134] Example 2:

[0135] The specific implementation process of the above method is described below with reference to specific application examples.

[0136] This embodiment proposes a method for calculating the prestress of an unbonded prestressed concrete containment shell. This method can simulate the stress distribution of unbonded PE steel strands under a single load, thereby obtaining the analysis results of the unbonded prestressed concrete containment shell under a single load, providing a basis for subsequent load combination and reinforcement calculation.

[0137] To achieve the above objectives, such as Figure 2 As shown, the method adopted in this invention includes steps 1 to 4:

[0138] Step 1. Determine the stress distribution principle of PE unbonded steel strands (prestressed tendons) based on the characteristics of PE unbonded steel strands.

[0139] Specifically, before calculating the stress distribution of unbonded prestressed steel strands in PE under a single load, two basic principles are first established:

[0140] 1) PE unbonded prestressed steel strands can slide freely along the length of the steel strand. Under a single load, the stress change of the entire steel strand is uniform.

[0141] 2) After single load analysis, the prestress change determined according to the first principle is the actual prestress change, and it does not need to be corrected again in load combination or reinforcement calculation.

[0142] Step 2. Perform a single load analysis as if the prestressed steel strands were bonded.

[0143] Specifically, for bonded and unbonded PE prestressed systems, under the same load, although the stress distribution of the internal steel strands is different, the total deformation of a single steel strand is the same. Therefore, following the design method for bonded systems, a single load analysis is performed on the unbonded PE steel strands. The deformation of all elements (finite element elements) in each steel strand is extracted, and the total deformation is obtained by summing them. This total deformation is also the total deformation of the unbonded PE steel strand under the same single load. The calculation formula is as follows:

[0144]

[0145] Where: ΔL—the total deformation (m) of a single steel strand after analysis based on bonded prestressed steel strands;

[0146] L—Total length of a single steel strand before loading (m);

[0147] E s —The elastic modulus of the steel strand (MPa);

[0148] s—the distance (m) from the element to the starting point of the steel strand;

[0149] Δσ 有粘结 —Calculated stress variation (MPa) for each element of the prestressed steel strand after analysis based on the bonded prestressed steel strand.

[0150] Reference Figure 3a and Figure 3b ,in Figure 3a and Figure 3b These represent the displacements of bonded and unbonded prestressed concrete containment structures under accidental pressure loads, such as... Figure 3a and Figure 3b As shown, the displacement of the unbonded prestressed concrete containment shell is very similar to that of the bonded prestressed concrete containment shell.

[0151] Step 3. Based on the stress distribution principle of unbonded PE steel strands, calculate the compensation stress of the unbonded PE steel strands and substitute it into the finite element model of the bonded containment for analysis.

[0152] Specifically, following the basic principles for calculating the stress distribution of unbonded PE steel strands established above, the total deformation of the steel strand is averaged according to its total length and elastic modulus to obtain the element stress variables of the redistributed unbonded PE steel strands. The calculation formula is as follows:

[0153] Δσ PE =ΔL / L×E s (2)

[0154] Where: Δσ PE —The actual stress change (MPa) of the unbonded prestressed steel strands in PE after the single deformation load analysis is completed;

[0155] The stress variable of each element with unbonded PE steel strands is subtracted from the stress variable of the corresponding element with bonded steel strands. The difference is the compensation stress load required to convert from bonded to unbonded PE. Directly applying this compensation stress to the model for calculation will introduce deviations due to the elastic deformation of concrete; therefore, the compensation stress needs to be corrected. The calculation formula is as follows:

[0156]

[0157] Where: σ 补偿 —The compensating stress load (MPa) required for the steel strand to be changed from bonded to unbonded PE;

[0158] A s —Area of ​​each steel bundle (m²) 2 );

[0159] s p — The distance between steel strands (m);

[0160] t—thickness of the containment structure (m);

[0161] E c —The elastic modulus of concrete (MPa).

[0162] Reference Figure 4a and Figure 4b ,in Figure 4a and Figure 4b These are the stresses of the prestressing tendons in bonded and unbonded prestressed concrete containment structures, respectively. Figure 4a and Figure 4b As shown, under accident pressure load, the stress in each steel strand of the unbonded prestressed concrete containment shell is basically uniform.

[0163] Step 4. Combine the analysis results of the bonded prestressed steel strands with the analysis results of the compensating stress to obtain the analysis results of the unbonded PE under a single load.

[0164] Specifically, the analysis results of the bonded prestressed concrete containment shell under a single load are combined with the analysis results of the modified compensating stress. The combined result is the analysis result of the unbonded prestressed concrete containment shell under this single load.

[0165] Figure 5 This diagram illustrates the stress distribution of typical inverted U-shaped prestressed tendons in bonded and unbonded prestressed containment structures. Post-processing of the analysis results for the bonded prestressed containment structure yields a theoretical actual stress value of 10.95 MPa for the unbonded prestressed tendons under accident pressure load. Figure 5 As can be seen, the stress in the typical inverted U-shaped prestressed steel strands of the unbonded prestressed containment is basically uniform and very close to the theoretical calculation value.

[0166] Figure 6 This diagram illustrates the stress distribution of typical horizontal prestressed steel strands in bonded and unbonded prestressed containment structures. Post-processing of the analysis results for the bonded prestressed containment structure yields a theoretical actual stress value of 33.56 MPa for the unbonded prestressed steel strands under accident pressure load. Figure 6 As can be seen, the stress in the typical horizontal prestressed steel strands of an unbonded prestressed containment is basically uniform and very close to the theoretical calculation value.

[0167] Figure 7 This diagram illustrates the stress distribution of horizontal prestressed steel strands in typical dome-shaped containment structures with and without bonded prestressing. Post-processing of the analysis results for the bonded prestressed containment structure yields a theoretical actual stress value of 18.45 MPa for the unbonded prestressed steel strands under accident pressure load. Figure 7 As can be seen, the stress in the horizontal prestressed steel strands of a typical dome in an unbonded prestressed containment structure is basically uniform and very close to the theoretical calculation value.

[0168] Understandably, this embodiment calculates the actual change value of unbonded prestress by extracting the total deformation of the bonded prestress based on the finite element analysis results. Then, based on the actual value of the unbonded prestress and the results of the bonded prestress, the compensation stress (first compensation stress load) is derived. The compensation stress is then used as a load input for finite element analysis and combined with the finite element results of the bonded prestress to finally obtain the finite element results of the unbonded prestress (first prestress). This result should not differ significantly from the calculated actual value.

[0169] In this embodiment, by determining the stress distribution principle of unbonded PE steel strands, analyzing single loads on bonded prestressed steel strands, incorporating the compensating stress of unbonded PE steel strands, and combining the analysis results of bonded prestressed steel strands with the analysis results of compensating stress, a more accurate analysis result under a single load on unbonded PE steel strands can be obtained compared with the existing stress calculation results of bonded prestressed concrete containment structures.

[0170] Example 3:

[0171] like Figure 8 As shown, the present invention also provides a prestress calculation device for the reinforcement of unbonded prestressed concrete containment structures, the device 100 comprising:

[0172] The module 11 is configured to acquire the first total deformation of a single unbonded steel strand under a preset single load.

[0173] The first obtaining module 12 is connected to the acquisition module 11 and is configured to obtain the first unit stress variable of the unbonded steel strand based on the first total deformation and the elastic modulus of the steel strand.

[0174] The second obtaining module 13 is connected to the first obtaining module 12. It is set to obtain the first compensation stress load required to transform the bonded steel strand into an unbonded steel strand based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand.

[0175] The determination module 14 is connected to the second obtaining module 13. It is set to determine the first prestress of the unbonded steel strand under the preset single load based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load.

[0176] In some embodiments, the acquisition module 11 is further configured to determine the second total deformation of a single bonded steel strand under a preset single load as the first total deformation of a single unbonded steel strand under a preset single load, specifically including:

[0177] The second total deformation of the bonded steel strand under a preset single load is calculated according to the following formula (1):

[0178]

[0179] Where ΔL is the second total deformation (m) of a single bonded steel strand; L is the total length (m) of a single steel strand before the load is applied; E s σ is the elastic modulus of the steel strand (MPa); s is the distance (m) from the starting point of the steel strand to the finite element element; Δσ 有粘结The stress variable (MPa) of the bonded prestressed steel strand under a preset single load is the second unit stress variable of the bonded steel strand.

[0180] The second total deformation is determined as the first total deformation of a single unbonded steel strand under a preset single load.

[0181] In some embodiments, the first obtaining module 12 is further configured to set that the stress change of the entire unbonded steel strand is uniform under a preset single load, and then calculate the first unit stress variable of the unbonded steel strand according to the following formula (2):

[0182] Δσ PE =ΔL / L×E s (2)

[0183] Where, Δσ PE Let be the first unit stress variable (MPa) of the unbonded prestressed steel strand, ΔL be the first total deformation (m) of a single unbonded steel strand, L be the total length (m) of a single unbonded steel strand before the load is applied, and E be the total stress variable (MPa) of the unbonded prestressed steel strand. s The modulus of elasticity (MPa) of unbonded steel strand.

[0184] In some embodiments, the second obtaining module 13 is further configured to calculate the second compensating stress load required for the unbonded steel strand according to the following formula (3):

[0185] σ 补偿 =Δσ PE -Δσ 有粘结 (3)

[0186] Where, σ 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand;

[0187] The second compensating stress load is corrected according to the following formula (4) to obtain the first compensating stress load required for the conversion of bonded steel strands into unbonded steel strands, in order to compensate for the deviation caused by the elastic deformation of concrete:

[0188]

[0189] in, σ represents the first compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; 补偿 The second compensating stress load (MPa) required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; A s The area of ​​each steel strand (m²) 2 );s p t is the distance between the steel strands (m); t is the thickness of the containment structure (m); Ec This is the elastic modulus of concrete (MPa).

[0190] In some embodiments, the determining module 14 is further configured to use finite element software to obtain the second prestress of the bonded steel strands in the bonded prestressed concrete containment structure under a preset single load, and,

[0191] Obtain the first compensating force of the bonded steel strands in the bonded prestressed concrete containment under the first compensating stress load;

[0192] The second prestress and the first compensating force are combined to obtain the first prestress of the unbonded steel strand in the unbonded prestressed concrete containment under a preset single load.

[0193] In some embodiments, the device further includes:

[0194] The combination module, connected to the determination module 14, is configured to calculate the first stress of the concrete in the unbonded prestressed concrete containment based on the first prestress of the unbonded steel strand under a preset single load.

[0195] It should be noted that this embodiment is a corresponding device for the prestress calculation method of unbonded prestressed concrete containment reinforcement in Embodiment 1 above. The method in Embodiment 1 can be implemented using this device. For specific implementation methods, please refer to the description in the prestress calculation method of unbonded prestressed concrete containment reinforcement. This embodiment will not be repeated here.

[0196] Example 4:

[0197] The present invention also provides a design apparatus for an unbonded prestressed concrete containment structure, comprising:

[0198] The prestress calculation device for the reinforcement of unbonded prestressed concrete containment as described in Example 3 is used to determine the first prestress of the unbonded steel strand under a preset single load.

[0199] The concrete design module, connected to the prestressing calculation device, is used to combine the first prestress and the preset single load to design the concrete in the unbonded prestressed concrete safety shell.

[0200] The containment design module, connected to the concrete design module, is used to design the containment based on the concrete.

[0201] In this embodiment, a design device for an unbonded prestressed concrete safety shell is constructed by determining a calculation device for the first prestress of the reinforcement of the unbonded prestressed concrete safety shell under a preset single load, a concrete design module for designing the concrete in the unbonded prestressed concrete safety shell, and a safety shell design module based on the designed concrete safety shell. This device can accurately simulate the stress change of the reinforcement in the unbonded prestressed concrete safety shell within the concrete shell, and design a safety shell with more accurate concrete stress calculation.

[0202] Example 5:

[0203] This embodiment also provides an unbonded prestressed concrete containment structure, comprising: concrete and steel strands composed of unbonded steel strands.

[0204] The unbonded prestressed concrete containment structure is designed using the device described in Example 4.

[0205] In this embodiment, the unbonded prestressed concrete containment shell designed using the device described in Embodiment 4 can accurately simulate the stress changes of the reinforcement in the concrete shell, resulting in more accurate calculation of concrete stress in the designed unbonded prestressed concrete containment shell.

[0206] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0207] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0208] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for calculating the prestress of reinforcement in an unbonded prestressed concrete containment shell, characterized in that, include: Obtain the first total deformation of a single unbonded steel strand under a preset single load; Based on the first total deformation and the elastic modulus of the steel strand, the first unit stress variable of the unbonded steel strand is obtained; Based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand, the first compensation stress load required to transform the bonded steel strand into an unbonded steel strand is obtained. Based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load, the first prestress of the unbonded steel strand under the preset single load is determined. The process of obtaining the total deformation of a single steel strand under a preset single load includes: The second total deformation of a single bonded steel strand under a preset single load is defined as the first total deformation of a single unbonded steel strand under a preset single load, which specifically includes: The second total deformation of the bonded steel strand under a preset single load is calculated according to the following formula (1): （1） in, The second total deformation of a single bonded steel strand; The total length of a single steel strand before the load is applied; The elastic modulus of the steel strand; The distance between the finite element element and the starting point of the steel strand; The second unit stress variable of bonded prestressed steel strand under a preset single load; The second total deformation is determined as the first total deformation of a single unbonded steel strand under a preset single load. The method for obtaining the first unit stress variable of the unbonded steel strand based on the first total deformation and the elastic modulus of the steel strand includes: Assuming that the stress change of the entire unbonded steel strand is uniform under a preset single load, the stress variable of the first unit of the unbonded steel strand is calculated according to the following formula (2): （2） in, The first element of the unbonded prestressed steel strand is the stress variable. The first total deformation of a single unbonded steel strand; The total length of a single unbonded steel strand before the application of load; The elastic modulus of unbonded steel strand; The first compensation stress load required to transform the bonded steel strand into an unbonded steel strand, based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand, specifically includes: The second compensating stress load required for the unbonded steel strand is calculated according to the following formula (3): （3） in, This is the second compensating stress load required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; The second compensating stress load is corrected according to the following formula (4) to obtain the first compensating stress load required for the conversion of bonded steel strands into unbonded steel strands, in order to compensate for the deviation caused by the elastic deformation of concrete: （4） in, This is the first compensating stress load required for the steel strand to be transformed from bonded steel strand to unbonded steel strand. This is the second compensating stress load required for the steel strand to be transformed from bonded steel strand to unbonded steel strand; The area of ​​each steel strand; The distance between the steel strands; The thickness of the containment structure; This refers to the elastic modulus of concrete.

2. The method for calculating the prestress of unbonded prestressed concrete containment shell reinforcement according to claim 1, characterized in that, The step of determining the first prestress of the unbonded steel strand under a preset single load based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load includes: Using finite element method (FEM) software, the second prestress of bonded steel strands in a bonded prestressed concrete containment structure under a preset single load was obtained, and... Obtain the first compensating force of the bonded steel strands in the bonded prestressed concrete containment under the first compensating stress load; The second prestress and the first compensating force are combined to obtain the first prestress of the unbonded steel strand in the unbonded prestressed concrete containment under a preset single load.

3. The method for calculating the prestress of unbonded prestressed concrete containment shell reinforcement according to any one of claims 1-2, characterized in that, The method further includes: Based on the determined first prestress of the unbonded steel strand under a preset single load, calculate the first stress of the concrete in the unbonded prestressed concrete containment.

4. A prestress calculation device for the reinforcement of an unbonded prestressed concrete containment shell, used in the prestress calculation method for the reinforcement of an unbonded prestressed concrete containment shell as described in any one of claims 1-3, characterized in that, The device includes: The acquisition module is configured to acquire the first total deformation of a single unbonded steel strand under a preset single load. The first obtaining module, connected to the acquisition module, is configured to obtain the first unit stress variable of the unbonded steel strand based on the first total deformation and the elastic modulus of the steel strand. The second obtaining module is connected to the first obtaining module. It is set to obtain the first compensation stress load required for the bonded steel strand to be transformed into an unbonded steel strand based on the first unit stress variable and the corresponding second unit stress variable of the bonded steel strand. The determination module is connected to the second obtained module, which is set to determine the first prestress of the unbonded steel strand under the preset single load based on the second prestress and the first compensating stress load of the bonded steel strand under the preset single load.

5. A design device for an unbonded prestressed concrete containment structure, characterized in that, include: The prestress calculation device for the reinforcement of unbonded prestressed concrete containment as described in claim 4 is used to determine the first prestress of the unbonded steel strand under a preset single load. The concrete design module, connected to the prestressing calculation device, is used to combine the first prestress and the preset single load to design the concrete in the unbonded prestressed concrete safety shell. The containment design module, connected to the concrete design module, is used to design the containment based on the concrete.

6. An unbonded prestressed concrete containment structure, characterized in that, include: Concrete and steel bundles made of unbonded steel strands, The unbonded prestressed concrete containment structure is designed using the design device described in claim 5.

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