Automatic adjusting method, system, medium and program product for design of prestress of steel truss support of beam string structure

Abstract

The invention relates to an automatic adjusting method, system, medium and program product for beam string structure steel truss support prestress design, and aims to improve the efficiency and safety of foundation pit engineering design. The method comprises the following steps: defining a pre-stress unit and setting target parameters, a combined stress ratio limit value covering axial force and bending moment, a pre-stress limit value, a boundary beam displacement limit value, a proportionality coefficient and an initial temperature value of pre-stress simulation; finite element model units are constructed, and each finite element model unit comprises a boundary beam, a soil spring, an inner support and a prestress unit; performing simulation analysis on the pre-stress unit through a temperature rise method to obtain pre-stress, structural deformation and internal force results; on the basis of applying soil pressure load analysis, an iterative algorithm is utilized to automatically adjust the simulation temperature of the prestress unit so as to realize the optimal prestress value. Compared with the prior art, the method has the advantages that through automatic processing, the complexity of manual adjustment is remarkably reduced, the time and the cost are saved, and meanwhile, the accuracy and the safety of structural design are ensured.

Description

Technical Field

[0001] The invention relates to the field of building foundation pit design, and in particular to an automatic adjustment method, system, medium and program product for prestressed design of beam-string steel truss supports. Background Art

[0002] During the construction of underground structures, it is crucial to ensure the stability and safety of the foundation pit and its surrounding environment. To this end, effective support, reinforcement and protection measures must be taken. In urban environments, deep foundation pit projects are often unavoidable, whether it is the construction of high-rise buildings or the development of subway systems. These foundation pit projects are usually close to important facilities such as transportation lines, existing buildings or underground pipelines. Therefore, in order to maintain the safety of the surrounding environment, and to improve construction efficiency and reduce costs, the beam-string steel truss structure is widely used due to its excellent performance.

[0003] When designing and analyzing the beam-string steel truss bracing system of a foundation pit, the traditional approach is to predict the behavior of the structure through finite element analysis. This process involves applying prestress to the components and repeatedly adjusting the prestress value based on the analysis results in order to obtain the optimal prestress configuration. However, this trial-and-error method is not only time-consuming but also labor-intensive, as it requires engineers to perform multiple iterative calculations and manual adjustments. Currently, there is a lack of a method that can automatically and efficiently determine the optimal prestress value, which limits the efficiency and accuracy of the design process. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide an automatic adjustment method, system, medium and program product for the prestressing design of the beam-string steel truss support, so as to optimize the prestressing design process of the beam-string steel truss support system.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A first aspect of the present invention provides an automatic adjustment method for prestressing design of a beam string steel truss support, comprising the following steps:

[0007] S1. Define the prestressed unit and set the target parameters: including the axial force N of the component, the horizontal bending moment Mx, the limit value j of the combined stress ratio f of the vertical bending moment My, the limit value k of the prestress P, the limit value m and the proportional coefficient r of the edge beam displacement S, and the temperature value t of the first iteration of the prestressed simulation;

[0008] S2. Establish finite element model units: including edge beam unit, soil spring unit, internal support unit, and prestressed unit;

[0009] S3. Perform prestress simulation analysis: Use the temperature rise method to simulate the prestress of the prestressed unit to obtain the prestress and the deformation and internal force results of the system;

[0010] S4. Apply soil pressure load analysis and iterative adjustment: obtain the deformation and internal force of the system, and automatically adjust the simulation temperature of the prestressed unit through an iterative algorithm to achieve the optimal prestress value.

[0011] Further, in S4, the iterative algorithm specifically includes the following steps:

[0012] S4-1. Determine whether the prestress value of the prestressed unit meets the preset limit k, and reduce the simulated temperature of the unit that does not meet the limit proportionally and continue the analysis;

[0013] S4-2. According to the displacement S of each node of the edge beam, adjust the simulation temperature of the prestressed unit to meet the set displacement limit m and proportional coefficient r;

[0014] S4-3. According to the stress ratio f of the internal support member, if it does not meet the requirements, replace it with a larger member model from the member library and continue the calculation to achieve the optimal prestress value.

[0015] Furthermore, the number of iterations n in the iterative algorithm is a preset value, and the program automatically ends after looping n times.

[0016] Furthermore, in S4-3, when there is no alternative component in the component library, the iteration ends.

[0017] Furthermore, S1 specifically includes the following steps:

[0018] S1-1. Define prestressed elements: Determine the location and characteristics of prestressed elements to simulate the connection between concrete and main supports and struts in the beam-string steel truss, as well as the application of prestress;

[0019] S1-2. Set target parameters, including:

[0020] Set the limit value j of the combined stress ratio f; this is a parameter determined by the combination of the axial force N, horizontal bending moment Mx, and vertical bending moment My of the member, and is used to evaluate the stress state of the member;

[0021] Set the limit value k of the prestress P: This is the upper limit of the prestressed axial force value of the prestressed unit, which is used to ensure that the prestress does not exceed the design safety value;

[0022] Set the limit value m and proportional coefficient r of the edge beam displacement S: The displacement S represents the displacement of the node on the edge beam in the direction perpendicular to the edge beam. The limit value m and proportional coefficient r are used to control the displacement within a safe range.

[0023] Set the temperature value t for the prestress simulation of the first iteration: This is the temperature at which the prestress element calculates the initial prestress value when the iterative calculation starts.

[0024] Furthermore, S2 specifically includes the following steps:

[0025] Establish edge beam unit: used to simulate the structure of concrete crown beam or waist beam;

[0026] Establish soil spring unit: used to simulate the interaction between the retaining structure and the soil;

[0027] Establishing inner support units: used to simulate inner support components, the inner support components include main support units, web member units, brace member units, and rod and tie rod units;

[0028] Establish a prestressed unit: used to simulate the application of prestress. The prestressed unit is the area connecting the concrete with the main support and the support rod.

[0029] Furthermore, S3 specifically includes the following steps:

[0030] S3-1. Use the temperature rise method to simulate the application of prestress: apply temperature to the prestress unit to make the prestress unit expand thermally. After the prestress expands thermally, both ends of the prestress unit are constrained to generate an axial force, thereby simulating the actual prestress effect;

[0031] S3-2. Obtain the deformation and internal force results of the prestressed unit: obtain the deformation and internal force distribution of the prestressed unit and the entire system through finite element analysis.

[0032] A second aspect of the present invention provides a computer system, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the above-mentioned automatic adjustment method for prestressed design of tension-string steel truss supports.

[0033] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned automatic adjustment method for prestressed design of a beam-string steel truss support.

[0034] A fourth aspect of the present invention is a computer program product, comprising a computer program, which, when executed by a processor, implements the above-mentioned automatic adjustment method for prestressed design of a beam-string steel truss support.

[0035] Compared with the prior art, the present invention has the following technical advantages:

[0036] 1) The present invention provides an automated method for adjusting the prestress in a beam string steel truss support structure, which greatly reduces the time and labor required by the traditional manual trial and error method. Through the automatic adjustment of the algorithm program, the designer can quickly obtain the optimal prestressing value, thereby improving the design efficiency and construction speed.

[0037] 2) The automated prestressing adjustment method of the present invention can ensure the safety of foundation pit engineering, and effectively reduce engineering costs by reducing unnecessary material waste and construction time. In addition, since the steps of manual calculation and adjustment are reduced, the safety risks caused by misjudgment are also reduced.

[0038] 3) The method of the present invention can ensure that the performance of the steel truss support structure reaches the best state during construction and use by accurately controlling the application of prestress. This not only improves the stability and bearing capacity of the structure, but also enhances its adaptability and reliability to environmental changes and potential destructive factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of a process for applying earth pressure load analysis and iterative adjustment in the present invention;

[0040] Figure 2 It is a structural schematic diagram of the finite element model unit established in the present invention. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0042] Example 1

[0043] In general, the automatic adjustment method for prestressing design of beam string steel truss support in this embodiment includes the following steps:

[0044] S1. Define the prestressed unit and set the target parameters: including the axial force N of the component, the horizontal bending moment Mx, the limit value j of the combined stress ratio f of the vertical bending moment My, the limit value k of the prestress P, the limit value m and the proportional coefficient r of the edge beam displacement S, and the temperature value t of the first iteration of the prestressed simulation;

[0045] S2. Establish finite element model units, see Figure 2 : Including edge beam unit, soil spring unit, internal support unit and prestressed unit;

[0046] S3. Perform prestress simulation analysis: Use the temperature rise method to simulate the prestress of the prestressed unit to obtain the prestress and the deformation and internal force results of the system;

[0047] S4. Apply soil pressure load analysis and iterative adjustment: obtain the deformation and internal force of the system, and automatically adjust the simulation temperature of the prestressed unit through an iterative algorithm to achieve the optimal prestress value.

[0048] The iterative algorithm specifically includes the following steps:

[0049] S4-1. Determine whether the prestress value of the prestressed unit meets the preset limit k, and reduce the simulated temperature of the unit that does not meet the limit proportionally and continue the analysis;

[0050] S4-2. According to the displacement S of each node of the edge beam, adjust the simulation temperature of the prestressed unit to meet the set displacement limit m and proportional coefficient r;

[0051] S4-3. According to the stress ratio f of the internal support member, if it does not meet the requirements, replace it with a larger member model from the member library and continue the calculation to achieve the optimal prestress value.

[0052] The number of iterations n in the iterative algorithm is a preset value, and the program ends automatically after looping n times. When there is no alternative component in the component library, the iteration ends.

[0053] In specific implementation, the finite element model units in this embodiment include: edge beam units are used to simulate concrete crown beams or waist beams; soil spring units are used to simulate the interaction between the retaining structure and the soil; internal support units are used to simulate internal support components including main support units, web members, strut units, and rod-pull units; prestressed units are connecting sections between concrete and the main supports and struts, which are used to simulate the application of prestress. The prestress simulation adopts the "heating method": temperature is applied to the prestressed unit to cause it to expand thermally. The two ends of the prestressed unit are constrained, which will generate an axial force, which is the simulated equivalent prestress; the soil pressure load acting vertically on the edge beam is used to simulate the effect of soil on the support.

[0054] For specific implementation, see Figure 1 , the specific algorithm for automatic prestress adjustment is:

[0055] 1. Set the initial parameters a, b, c, j, k, m, t.

[0056] The limit value j of the combined stress ratio f: The combined stress ratio f is the combination of the axial force N, horizontal bending moment Mx and vertical bending moment My of the component: f = N / a + Mx / b + My / c, where a, b, c are the basic mechanical parameters of the component, which can be set separately for different types of components.

[0057] Limit value k of prestress P: Prestress P represents the prestressed axial force value of the prestressed unit. Different limit values ​​can be set for different types of components.

[0058] Limit m and proportional coefficient r of the side beam displacement S: The deformation S represents the displacement of the node on the side beam in the direction perpendicular to the side beam. Positive means inward displacement, negative means outward displacement. Different side beam unit segments can set the displacement limit separately. The proportional coefficient r is less than 1 and is used to limit the displacement range. For example, r = 0.9, the displacement can be limited to between 0.9*m and m

[0059] Temperature value t of the prestress simulation for the first iteration: The prestress unit calculates the initial prestress based on this temperature and starts the calculation iteration.

[0060] Iteration number n: The program loops n times and ends automatically

[0061] 2. Calculate the basic working conditions in sequence, with each working condition being based on the previous working condition.

[0062] Working condition 1: Prestress simulation analysis, applying temperature to the prestressed unit to obtain the prestress and the deformation and internal force results of the system.

[0063] Working condition 2: Apply soil pressure load analysis to obtain the deformation and internal force of the system.

[0064] 3. Iterative Algorithm

[0065] (1) Condition 1 calculates the prestress value of each prestressed unit and makes a judgment. Prestressed units with P1≤k1, P2≤k2… (the limit value k can be set uniformly or by category) are not adjusted. For prestressed units with P1>k1, P2>k2…, the simulated temperature applied to the prestressed units is reduced by a certain proportion. Condition 1 analysis is continued until all prestressed units meet the condition of P1≤k1, P2≤k2… and then proceed to the next step.

[0066] There are prestressed units at both ends of the main support to keep the simulation temperature of the prestressed units at both ends consistent.

[0067] (2) Under working condition 2, the displacement S of each node of the edge beam is calculated. When S>m, the simulated temperature of the prestressed unit closest to the node is increased proportionally to increase the prestress. When S<n*m, the simulated temperature of the prestressed unit closest to the node is decreased proportionally (if there are two prestressed units closest to the node, adjust them together) to reduce the prestress, so that all node displacements satisfy r*m≤S≤m.

[0068] There are prestressed units at both ends of the main support. If one end of the edge beam nodes governed by the prestressed units meets the displacement requirement of r*m≤S≤m, the other end only needs to meet S≤m. S can be positive or negative.

[0069] (3) Working condition 2 calculates the stress ratio f of the internal support components. When the stress ratio f of some components is greater than j, the stress ratio does not meet the requirements. It is necessary to replace the component model with a larger one from the optional component library and continue the calculation until the stress ratio of all components meets the requirements.

[0070] When there are no alternative components in the component library, the program ends automatically and the reason for the end is prompted.

[0071] Example 2

[0072] The present embodiment provides a computer system, which realizes an efficient and automated automatic adjustment method for the prestressing design of the steel truss brace of the tension string beam by integrating a memory, a processor and a computer program stored in the memory. The processor executes the computer program to automatically define the prestressing unit and set key target parameters, such as the limit value j of the combined stress ratio f of the axial force N, horizontal bending moment Mx and vertical bending moment My of the component, the limit value k of the prestressing force P, the limit value m and the proportional coefficient r of the displacement S of the side beam, and the temperature value t of the prestressing simulation of the first iteration. The system further establishes a finite element model unit, including a side beam unit, a soil spring unit, an internal support unit and a prestressing unit, and uses the "heating method" to simulate the application of prestressing force, so as to accurately simulate the physical behavior of the actual structure in a virtual environment.

[0073] The core advantage of the computer system of this embodiment lies in its automated iterative algorithm as in Example 1, which can intelligently adjust the simulated temperature of the prestressed unit to achieve the optimal prestress value. This process not only includes automatic judgment and adjustment of the prestress value, but also involves precise control of the displacement of the side beams and the stress ratio of the internal support members to ensure that all design parameters meet the established safety and performance standards. In this way, the present invention greatly improves the efficiency and accuracy of foundation pit engineering design, reduces the tedious manual calculations and adjustments in traditional design methods, and also reduces the human errors that may occur in the design process, bringing significant technological progress to the field of building foundation pit design.

[0074] Example 3

[0075] The computer-readable storage medium provided in this embodiment has a computer program stored thereon, and when the program is executed by a processor, a series of automated steps can be implemented for an automatic adjustment method for the prestressed design of a beam-string steel truss support. This innovative method significantly improves the efficiency and accuracy of foundation pit engineering design through intelligent algorithms, and reduces the tedious manual calculations and adjustments in traditional design methods. Specifically, the computer program includes multiple steps such as defining prestressed units, setting target parameters, establishing finite element model units, performing prestressed simulation analysis, and applying soil pressure load analysis. Through these steps, the program can automatically adjust the simulated temperature of the prestressed unit to achieve the optimal prestress value, thereby saving a lot of energy and time, and improving the safety and reliability of the structural design.

[0076] Example 4

[0077] The computer program product provided in this embodiment includes a computer program, which can realize a revolutionary automatic adjustment method for the prestressed design of the steel truss support of the string beam when executed by the processor. This method significantly improves the efficiency and accuracy of the foundation pit engineering design through intelligent algorithms, and reduces the tedious manual calculations and adjustments in the traditional design methods. Specifically, the computer program includes multiple steps such as defining prestressed units, setting target parameters, establishing finite element model units, performing prestressed simulation analysis, and applying soil pressure load analysis. Through these steps, the program can automatically adjust the simulated temperature of the prestressed unit to achieve the optimal prestressed value, thereby saving a lot of energy and time, and improving the safety and reliability of the structural design. In addition, the program can also intelligently adjust the simulated temperature of the prestressed unit according to the displacement of each node of the edge beam and the stress ratio of the internal support member, ensuring that all design parameters meet the established safety and performance standards. When there is no alternative component in the component library, the program will automatically end and prompt the reason for the end, further optimizing the design process. This automated prestressed design adjustment method not only improves the design efficiency, but also ensures the construction quality and structural safety, bringing significant technological progress to the field of building foundation pit design.

[0078] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An automatic adjustment method for prestressing design of beam string steel truss support, characterized in that: The following steps are involved: S1. Define the prestressed unit and set the target parameters: including the axial force N of the component, the horizontal bending moment Mx, the limit value j of the combined stress ratio f of the vertical bending moment My, the limit value k of the prestress P, the limit value m and the proportional coefficient r of the edge beam displacement S, and the temperature value t of the first iteration of the prestressed simulation; S2. Establish finite element model units: including edge beam unit, soil spring unit, internal support unit, and prestressed unit; S3. Perform prestress simulation analysis: Use the temperature rise method to simulate the prestress of the prestressed unit to obtain the prestress and the deformation and internal force results of the system; S4. Apply soil pressure load analysis and iterative adjustment: obtain the deformation and internal force of the system, and automatically adjust the simulation temperature of the prestressed unit through an iterative algorithm to achieve the optimal prestress value.

2. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 1, characterized in that: In S4, the iterative algorithm specifically includes the following steps: S4-1. Determine whether the prestress value of the prestressed unit meets the preset limit k, and reduce the simulated temperature of the unit that does not meet the limit proportionally and continue the analysis; S4-2. According to the displacement S of each node of the edge beam, adjust the simulation temperature of the prestressed unit to meet the set displacement limit m and proportional coefficient r; S4-3. According to the stress ratio f of the internal support member, if it does not meet the requirements, replace it with a larger member model from the member library and continue the calculation to achieve the optimal prestress value.

3. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 2, characterized in that: The number of iterations n in the iterative algorithm is a preset value, and the program automatically ends after looping n times.

4. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 2, characterized in that: In S4-3, when there are no alternative components in the component library, the iteration ends.

5. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 1, characterized in that: S1 specifically includes the following steps: S1-1. Define prestressed elements: Determine the location and characteristics of prestressed elements to simulate the connection between concrete and main supports and struts in the beam-string steel truss, as well as the application of prestress; S1-2. Set target parameters, including: Set the limit value j of the combined stress ratio f; Set the limit value k of the prestress P: Set the limit value m and proportional coefficient r of the edge beam displacement S: The displacement S represents the displacement of the node on the edge beam in the direction perpendicular to the edge beam. The limit value m and proportional coefficient r are used to control the displacement within a safe range; Sets the temperature value t for the first iteration of the prestressing simulation.

6. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 1, characterized in that: S2 specifically includes the following steps: Establish edge beam unit: used to simulate the structure of concrete crown beam or waist beam; Establish soil spring unit: used to simulate the interaction between the retaining structure and the soil; Establishing inner support units: used to simulate inner support components, the inner support components include main support units, web member units, brace member units, and rod and tie rod units; Establish a prestressed unit: used to simulate the application of prestress. The prestressed unit is the area connecting the concrete with the main support and the support rod.

7. The automatic adjustment method for prestressing design of beam string steel truss support according to claim 1, characterized in that: S3 specifically includes the following steps: S3-1. Use the temperature rise method to simulate the application of prestress: apply temperature to the prestress unit to make the prestress unit expand thermally. After the prestress expands thermally, both ends of the prestress unit are constrained to generate an axial force, thereby simulating the actual prestress effect; S3-2. Obtain the deformation and internal force results of the prestressed unit: obtain the deformation and internal force distribution of the prestressed unit and the entire system through finite element analysis.

8. A computer system comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the automatic adjustment method for prestressing design of a beam-string steel truss support as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the automatic adjustment method for prestressing design of a beam-string steel truss support described in any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the automatic adjustment method for prestressing design of a beam-string steel truss support as described in any one of claims 1 to 7 is implemented.

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