A method and system for preventing and controlling cross slopes in manufacturing large-section split steel box girders

Abstract

The invention discloses a method and system for preventing and controlling a transverse slope in manufacturing a large-section split steel box girder. The method comprises: obtaining steel box girder data, wherein the steel box girder data comprises: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder under a reference state; setting a transverse slope change evaluation model for the steel box girder, and calculating a transverse slope change index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope change evaluation model for the steel box girder comprises calculating a temperature at a certain position when manufacturing the steel box girder and calculating a stress distribution index at a certain position when manufacturing the steel box girder; and setting a transverse slope threshold value, and when the transverse slope change index exceeds the transverse slope threshold value, issuing an alarm message until the transverse slope change index is lower than the transverse slope threshold value.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel box girder manufacturing optimization, and more specifically, relates to a method and system for preventing and controlling a transverse slope in manufacturing a large-section split steel box girder. Background Art

[0002] With the rapid development of bridge construction in my country, steel bridges are increasingly used in large bridges, especially split steel box girder structures, which are favored due to their unique advantages. Split steel box girders are usually composed of two or three main boxes, which are connected by cross beams to form an integral structure. This structure has the characteristics of less material, light weight, and easy construction of ultra-wide bridge decks, which can meet the needs of multiple types of traffic and multiple lanes. In addition, split steel box girders also have good seismic and wind resistance, and are suitable for cable-stayed bridges, suspension bridges, and more complex cable-stayed and suspension combined system bridges. However, due to the discontinuous rigidity of its cross section, split steel box girders face the challenge of cross slope accuracy control during the manufacturing process, especially in the case of large sections, the cross slope control is more difficult.

[0003] At present, the traditional steel box girder manufacturing method is mainly aimed at the whole section flat streamlined steel box girder, and its cross slope control is relatively simple, usually achieved by adjusting the welding sequence and tooling support. For the split steel box girder, there are also some attempts in the existing technology, but most of them are based on the manufacturing experience of general steel box girders, and lack of in-depth research on the special structural characteristics of the split steel box girder. Therefore, the difficulty of cross slope control increases.

[0004] Therefore, there is an urgent need for a technical solution that can prevent and control the cross slope, thereby improving manufacturing accuracy. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a cross slope prevention and control method for manufacturing a large-section split steel box girder, comprising:

[0006] Acquire steel box girder data, the steel box girder data including: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state;

[0007] Setting a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when the steel box girder is manufactured and calculating a stress distribution index at a certain position when the steel box girder is manufactured;

[0008] A cross slope threshold is set, and when the cross slope change index exceeds the cross slope threshold, an alarm message is issued until the cross slope change index is lower than the cross slope threshold.

[0009] Furthermore, the transverse slope change assessment model of the steel box girder includes:

[0010] ,

[0011] in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, The stress distribution index at is used to describe the stress distribution. The third adjustment factor of the model is evaluated for the cross slope variation of the steel box girder.

[0012] Further, time When manufacturing steel box beams, Temperature include:

[0013] ,

[0014] in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

[0015] Further, time When manufacturing steel box beams, the The stress distribution index at include:

[0016] ,

[0017] in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

[0018] Further, time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel include:

[0019] ,

[0020] in, The steel is at the reference temperature The expansion coefficient under Impact Factor The first adjustment factor is Impact Factor The second adjustment factor.

[0021] Further, time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel include:

[0022] ,

[0023] in, The steel is at the reference temperature The elastic modulus below.

[0024] The present invention also provides a cross slope prevention control system for manufacturing a large-section split steel box girder, comprising:

[0025] A data acquisition module is used to acquire steel box girder data, wherein the steel box girder data includes: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state;

[0026] Setting a model module, used to set a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when manufacturing the steel box girder and calculating a stress distribution index at a certain position when manufacturing the steel box girder;

[0027] The alarm module is used to set a cross slope threshold value. When the cross slope change index exceeds the cross slope threshold value, an alarm message is issued until the cross slope change index is lower than the cross slope threshold value.

[0028] Furthermore, the transverse slope change assessment model of the steel box girder includes:

[0029] ,

[0030] in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, the The stress distribution index at is used to describe the stress distribution. The third adjustment factor of the model is evaluated for the cross slope variation of the steel box girder.

[0031] Further, time When manufacturing steel box beams, the Temperature include:

[0032] ,

[0033] in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

[0034] Further, time When manufacturing steel box beams, the The stress distribution index at include:

[0035] ,

[0036] in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

[0037] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art:

[0038] Through the above technical scheme, the present invention can monitor the cross slope in real time during the manufacturing process of the split steel box girder, remind the manufacturing personnel to pay attention to preventing the cross slope through alarm information, and improve the manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a flow chart of the method of embodiment 1 of the present invention;

[0040] Figure 2 It is a schematic diagram of a special assembly tool of Example 3 of the present invention;

[0041] Figure 3 Schematic diagram of monitoring point settings in Embodiment 3 of the present invention;

[0042] Figure 4 It is a system structure diagram of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0043] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0044] The method provided by the present invention can be implemented in the following terminal environment, and the terminal may include one or more of the following components: a processor, a storage medium, and a display screen. The storage medium stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method described in the following embodiment.

[0045] The processor may include one or more processing cores. The processor uses various interfaces and lines to connect various parts in the entire terminal, and executes various functions of the terminal and processes data by running or executing instructions, programs, code sets or instruction sets stored in the storage medium, and calling data stored in the storage medium.

[0046] The storage medium may include a random access memory (RAM) or a read-only memory (ROM). The storage medium may be used to store instructions, programs, codes, code sets or instructions.

[0047] The display screen is used to display the user interface of each application.

[0048] In addition, those skilled in the art can understand that the structure of the above terminal does not constitute a limitation on the terminal, and the terminal may include more or fewer components, or combine certain components, or arrange the components differently. For example, the terminal also includes components such as a radio frequency circuit, an input unit, a sensor, an audio circuit, and a power supply, which will not be described in detail here.

[0049] Example 1

[0050] like Figure 1 As shown, the embodiment of the present invention provides a method for preventing and controlling the cross slope of a large-section split steel box girder, comprising:

[0051] Step 101, obtaining steel box girder data, the steel box girder data including: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state;

[0052] Step 102, setting a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when the steel box girder is manufactured and calculating a stress distribution index at a certain position when the steel box girder is manufactured;

[0053] Specifically, the transverse slope change assessment model of the steel box girder includes:

[0054] ,

[0055] in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, the The stress distribution index at is used to describe the stress distribution. The third adjustment factor of the model is evaluated for the cross slope variation of the steel box girder.

[0056] Specifically, time When manufacturing steel box beams, the Temperature include:

[0057] ,

[0058] in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

[0059] Specifically, time When manufacturing steel box beams, the The stress distribution index at include:

[0060] ,

[0061] in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

[0062] Specifically, time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel include:

[0063] ,

[0064] in, The steel is at the reference temperature The expansion coefficient under Impact Factor The first adjustment factor is Impact Factor The second adjustment factor.

[0065] Specifically, time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel include:

[0066] ,

[0067] in, The steel is at the reference temperature The elastic modulus below.

[0068] Step 103, setting a cross slope threshold, when the cross slope change index exceeds the cross slope threshold, issuing an alarm message until the cross slope change index is lower than the cross slope threshold.

[0069] Example 2

[0070] like Figure 4 As shown, the embodiment of the present invention also provides a cross slope prevention control system for manufacturing a large-section split steel box girder, comprising:

[0071] A data acquisition module is used to acquire steel box girder data, wherein the steel box girder data includes: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state;

[0072] Setting a model module, used to set a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when manufacturing the steel box girder and calculating a stress distribution index at a certain position when manufacturing the steel box girder;

[0073] Specifically, the transverse slope change assessment model of the steel box girder includes:

[0074] ,

[0075] in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, the The stress distribution index at is used to describe the stress distribution. The third adjustment factor of the model is evaluated for the cross slope variation of the steel box girder.

[0076] Specifically, time When manufacturing steel box beams, the Temperature include:

[0077] ,

[0078] in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

[0079] Specifically, time When manufacturing steel box beams, the The stress distribution index at include:

[0080] ,

[0081] in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

[0082] Specifically, time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel include:

[0083] ,

[0084] in, The steel is at the reference temperature The expansion coefficient under Impact Factor The first adjustment factor is Impact Factor The second adjustment factor.

[0085] Specifically, time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel include:

[0086] ,

[0087] in, The steel is at the reference temperature The elastic modulus below.

[0088] The alarm module is used to set a cross slope threshold. When the cross slope change index exceeds the cross slope threshold, an alarm message is issued until the cross slope change index is lower than the cross slope threshold.

[0089] Example 3

[0090] like Figure 2 As shown, this embodiment designs a special assembly tooling to set the cross slope and pre-deformation of the split steel box girder according to the requirements for setting the pre-deformation of the cross slope of the split steel box girder, combined with the structural dimensions and characteristics of the split steel box girder, and performs the setting of the cross slope and pre-deformation of the split steel box girder. Through structural force calculation, the bearing capacity requirements of the designed tooling are determined, and at the same time, it has an anti-deformation function, so that the split steel box girder is in or close to a stress-free state when assembled on the tooling. The tooling structure depends on the construction content and conditions. For the split steel box girder that has been made into an independent box for overall segment assembly, the support position and support method can be designed according to each box structure to ensure the support bearing capacity, stability and deformation requirements. The present application adopts high-precision external tooling constraints, and changes the pre-arch of the cross slope through tooling adjustment, and uses the cross partition in the box as an inner mold to strictly control the assembly gap and size, which can achieve effective control of the assembly accuracy of the cross slope of the split steel box girder, and form a total assembly control system for manufacturing the cross slope of the split steel box girder.

[0091] like Figure 3 As shown, in this embodiment, monitoring points will be set to detect the cross slope after the cross slope of the split steel box girder is assembled and welded; the feasibility of the manufacturing process is verified by the first product, and the reliability of the tooling is verified; the stability of the cross slope control target of the split steel box girder is achieved by process monitoring, and the cross slope manufacturing target requirements are met. On the top surface of each box body of the split steel box girder, no less than four monitoring points are arranged to detect the cross slope after the structure is assembled and welded. The monitoring points should be arranged at the intersection of the transverse partitions, longitudinal partitions or longitudinal ribs to prevent the measuring points from being unstable; the monitoring points can be welded to the top surface of the box body using cylindrical steel columns and painted with marking colors.

[0092] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0093] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] In the several embodiments provided by the present invention, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0095] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0096] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0097] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only storage medium (ROM, Read-Only Memory), random access storage medium (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0098] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preventing and controlling the cross slope in manufacturing a large-section split steel box girder, characterized in that: include: Acquire steel box girder data, the steel box girder data including: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state; Setting a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when the steel box girder is manufactured and calculating a stress distribution index at a certain position when the steel box girder is manufactured; The cross slope variation assessment model of the steel box girder includes: ， in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, the Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, The stress distribution index at is used to describe the stress distribution. A third adjustment factor in the model was evaluated for cross slope variation of the steel box girder; A cross slope threshold is set, and when the cross slope change index exceeds the cross slope threshold, an alarm message is issued until the cross slope change index is lower than the cross slope threshold.

2. A method for preventing and controlling cross slopes in manufacturing a large-section split steel box girder as claimed in claim 1, characterized in that: time When manufacturing steel box beams, the Temperature include: ， in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

3. A method for preventing and controlling cross slopes in manufacturing a large-section split steel box girder as claimed in claim 2, characterized in that: time When manufacturing steel box beams, The stress distribution index at include: ， in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

4. A method for preventing and controlling cross slopes in manufacturing a large-section split steel box girder as claimed in claim 3, characterized in that: time When manufacturing steel box beams, the Temperature Factors affecting the expansion coefficient of steel include: ， in, The steel is at the reference temperature The expansion coefficient under Impact Factor The first adjustment factor is Impact Factor The second adjustment factor.

5. A method for preventing and controlling cross slopes in manufacturing large-section split steel box girders as claimed in claim 4, characterized in that: time When manufacturing steel box beams, Temperature Factors affecting the elastic modulus of steel include: ， in, The steel is at the reference temperature The elastic modulus below.

6. A cross slope prevention control system for manufacturing large-section split steel box girders, characterized in that: include: A data acquisition module is used to acquire steel box girder data, wherein the steel box girder data includes: the length of the steel box girder at a certain position, the Poisson's ratio of the steel material, the curvature radius of the steel box girder at a certain position, and the curvature radius of the steel box girder in a reference state; Setting a model module, used to set a transverse slope variation evaluation model of a steel box girder, and calculating a transverse slope variation index of the steel box girder at a certain position according to the steel box girder data, wherein the transverse slope variation evaluation model of the steel box girder includes calculating a temperature at a certain position when manufacturing the steel box girder and calculating a stress distribution index at a certain position when manufacturing the steel box girder; The cross slope variation assessment model of the steel box girder includes: ， in, For time When the steel box girder is in position The cross slope variation index at For steel box girder in position The length of For time When manufacturing steel box beams, Temperature Factors affecting the expansion coefficient of steel, For time When manufacturing steel box beams, Temperature Factors affecting the elastic modulus of steel, is the Poisson’s ratio of steel, For time When the steel box girder is in position The radius of curvature at is the curvature radius of the steel box girder in the reference state, The first adjustment factor of the model for evaluating the cross slope variation of the steel box girder, The second adjustment factor of the model for evaluating the cross slope variation of the steel box girder, is the reference temperature, For time When manufacturing steel box beams, The stress distribution index at is used to describe the stress distribution. A third adjustment factor in the model was evaluated for cross slope variation of the steel box girder; The alarm module is used to set a cross slope threshold. When the cross slope change index exceeds the cross slope threshold, an alarm message is issued until the cross slope change index is lower than the cross slope threshold.

7. A slope prevention control system for manufacturing a large-section split steel box girder as claimed in claim 6, characterized in that: time When manufacturing steel box beams, Temperature include: ， in, For steel box girder in position The temperature change at For temperature The first adjustment factor is is the position when the reference temperature is collected, For temperature The second adjustment factor is is the frequency of temperature fluctuation, For temperature The third adjustment factor is For temperature The fourth adjustment factor is For temperature The fifth adjustment factor.

8. A cross slope prevention control system for manufacturing a large-section split steel box girder as claimed in claim 7, characterized in that: time When manufacturing steel box beams, The stress distribution index at include: ， in, is the stress distribution index The first adjustment factor is For time When the steel box girder is in position The lateral displacement at is the stress distribution index The second adjustment factor is is the stress distribution index The third adjustment factor is is the stress distribution index The fourth adjustment factor is is the stress distribution index The fifth adjustment factor, It is the time evolution constant of the stress on the steel and is used to describe the stress accumulation of the steel during the processing.

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