Servo steel support optimal arrangement method based on stress synergic response of support system

Abstract

This invention discloses a servo-supported steel support optimization layout method based on the stress-coordinated response of the support system. First, a three-dimensional numerical model reflecting the true geometric and approximate mechanical properties of the ancient ship, the soil, and the existing support system is constructed. Second, through initial working condition simulation, the key areas of the shipwreck structure most in need of support reinforcement are identified. Then, around these key areas, multiple servo-support layout schemes are designed, and a series of axial force threshold combinations are set for each scheme. Next, the entire process from excavation to completion is fully simulated in a numerical environment, and the effectiveness of each scheme in controlling hull displacement and stress is quantitatively evaluated. Finally, by comparing all simulation results, the optimal scheme is selected, and its corresponding support layout diagram and axial force threshold matrix are extracted as the design basis for on-site implementation. This invention can provide a quantitative design basis for the refined and dynamic support of fragile cultural relics such as ancient ships in archaeological excavations, effectively improving support efficiency and structural safety.

Description

Technical Field

[0001] This invention relates to the field of civil engineering structural support and cultural relic protection technology, and in particular to a servo steel support optimization arrangement method based on the stress-coordinated response of the support system. Background Technology

[0002] With the successful salvage of large ancient shipwrecks such as the "Yangtze River Estuary No. 2" and the commencement of indoor archaeological work, ensuring the stability of the fragile ship structure during the excavation of the underlying soil and interior compartments has become a key technical challenge. Servo-driven steel support systems, due to their dynamically adjustable axial force, have shown application potential in such sophisticated engineering projects. However, there is still no mature method for scientifically determining the placement of servo supports and the appropriate axial force value that changes with the excavation process in irregular and space-constrained archaeological environments.

[0003] The main bottlenecks currently faced include: (1) The ancient ship has a complex structure and unknown material constitutive properties, making it difficult to apply traditional mechanical analysis directly; (2) The excavation process is dynamic, and the "optimal" state of the support changes with the working conditions, making static design methods inapplicable; (3) Existing servo support research focuses on the deformation control of conventional foundation pit retaining structures, lacking optimization targets and evaluation systems for the dual control of stress and deformation of the cultural relic itself. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for optimizing the arrangement of servo steel supports based on the stress-coordinated response of the support system. This method is used in the archaeological excavation of fragile cultural relics such as ancient shipwrecks to determine the optimal arrangement position and the optimal axial force threshold of the servo steel support system through numerical simulation optimization.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for optimizing the layout of servo steel supports based on the stress-coordinated response of a support system. The method comprises the following steps: Step 1: Establishing a three-dimensional numerical model of the ancient shipwreck-soil-support structure: Based on three-dimensional scanning data from the archaeological site, a three-dimensional finite element model is constructed, including the shipwreck body, the surrounding and internal soil, and the existing support structure; Step 2: Identifying key support areas: Based on the model established in Step 1, initial or typical excavation conditions are simulated, the stress and displacement fields of the shipwreck structure are analyzed, and stress concentration areas and areas with large displacements are identified as the basis for the servo steel support layout. Potential key locations; Step 3, determine the servo support layout and axial force optimization scheme: set multiple spatial layout schemes of servo steel supports and their corresponding axial force threshold combinations, simulate the complete excavation process one by one in the numerical model, and compare and analyze the control effect of different schemes on the displacement and stress of the shipwreck structure; Step 4, output the optimal support parameters: with the optimization goal of controlling the deformation and stress of the shipwreck structure, select the optimal servo steel support spatial layout scheme from the simulation results of Step 3, and determine the optimal axial force threshold of each support at different excavation stages, forming a staged axial force threshold matrix.

[0007] Furthermore, the servo steel support optimization arrangement method based on the stress-coordinated response of the support system provided by the present invention may also have the following features: In step 1, the model of the ancient shipwreck body adopts a transversely isotropic elastic constitutive model, which is obtained by inversion of monitoring data.

[0008] Furthermore, the servo steel support optimization arrangement method based on the stress-coordinated response of the support system provided by the present invention may also have the following feature: in step 1, the soil model adopts the Mohr-Coulomb model.

[0009] Furthermore, the servo steel support optimization arrangement method based on the stress cooperative response of the support system provided by the present invention may also have the following features: in step 2, the stress concentration areas and large displacement areas of the hull, support and fishbone are identified respectively.

[0010] Furthermore, the servo steel support optimization arrangement method based on the stress-coordinated response of the support system provided by the present invention may also have the following features: In step 3, the mechanical behavior of the servo steel support in the numerical model is simplified as follows: when the absolute value of the support axial force is less than a preset threshold, it behaves as a linear spring; when the axial force reaches the preset threshold, the axial force is kept constant at the threshold level.

[0011] Furthermore, the servo steel support optimization arrangement method based on the stress-coordinated response of the support system provided by the present invention may also have the following features: the axial force threshold matrix is ​​a two-dimensional data table, where rows represent different excavation stages or depths, columns represent each servo steel support, and the table element values ​​are the suggested axial force control thresholds for the support at the corresponding stage.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) More targeted: The stress and deformation of the ancient ship's main structure are used as the core optimization indicators, rather than the deformation of the traditional foundation pit retaining structure, which is more in line with the needs of cultural relic protection.

[0014] (2) Refined design process: The use of numerical simulation methods can fully consider the dynamics of the entire excavation process, the soil-structure interaction, and the nonlinear mechanical behavior of the servo support, resulting in more accurate design results. This avoids the problems of low support efficiency or excessive local stress caused by the reliance on experience in traditional technology.

[0015] (3) The output results are operable: the final output of the "optimal layout scheme" and "axial force threshold matrix" are specific and quantitative construction guidance parameters that can be directly used to guide the on-site installation and initial setting of the servo system.

[0016] (4) It has the function of pre-testing and evaluation: the effect of different support strategies can be evaluated in advance during the design stage, which is conducive to the comparison of multiple options and risk prediction. Attached Figure Description

[0017] Figure 1 This is an overall flowchart of the servo steel support optimization arrangement method based on the stress cooperative response of the support system in the embodiments of the present invention;

[0018] Figure 2 This is a simplified mechanical principle diagram of the servo steel support in the numerical model in an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the steel support arrangement at the ancient ship archaeological site in an embodiment of the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0021] Please see Figure 1 This embodiment takes the Yangtze River Estuary No. 2 ancient shipwreck as an example to provide a servo steel support optimization arrangement method based on the stress cooperative response of the support system. The method is carried out according to the following steps:

[0022] Step 1: Determining the Numerical Simulation Model

[0023] Precise point cloud data of the Yangtze River Estuary No. 2 ancient shipwreck, the external arc-shaped beam protective structure, and the internal soil were obtained using three-dimensional laser scanning technology.

[0024] Based on the aforementioned 3D scanning data, a 3D numerical model of the ancient shipwreck-soil-support structure was constructed in Abaqus finite element software, encompassing the shipwreck body, surrounding and internal soil, and existing support structures. The shipwreck body model employs a transversely isotropic elastic constitutive model, with parameters such as the elastic modulus and Poisson's ratio preliminarily determined through inversion from previous monitoring data. The soil was modeled using the Mohr-Coulomb model. The existing steel supports were simulated using beam elements in Abaqus.

[0025] Step 2: Key Area Identification

[0026] Based on the model established in step 1, the entire process of soil excavation and support is simulated within the model. Stress and displacement cloud maps are obtained after analysis and calculation. After data export, stress concentration areas and areas of significant displacement in the hull, supports, and herringbone structure are identified for each analysis step. These stress concentration areas and areas of significant displacement serve as potential key points for the deployment of servo steel supports. The determination of whether stress is "concentrated" and what kind of displacement is "significant" can be automatically calculated through pre-set thresholds.

[0027] Step 3: Scheme Design and Simulation

[0028] Determine the servo support layout and axial force optimization scheme:

[0029] For critical areas (stress concentration zones and areas with large displacements), multiple spatial arrangement schemes of servo steel supports and their corresponding axial force threshold combinations were set. The complete excavation process was simulated one by one in the numerical model, and the control effects of different schemes on the displacement and stress of the shipwreck structure were compared and analyzed. The mechanical behavior of the servo steel supports in the numerical model was simplified as follows: when the absolute value of the axial force of the support is less than the preset threshold, it behaves like a linear spring; when the axial force reaches the preset threshold, the axial force is kept constant at the threshold level.

[0030] In this embodiment, please refer to Figure 2 First, a single-servo steel scheme was designed and a low axial force threshold was set. Then, by controlling the relative displacement and the applied concentrated force, the following was achieved: Figure 2The diagram shows the replacement of supports with servo steel supports: boundary conditions are set with specified connection displacements; ① indicates an external load applied based on the connection displacement; ② indicates a converter is set at the connection section, allowing only radial (U1) deformation; and the connector stiffness (D11) in the x-direction is given based on the elastic model. For each combination, a full-process numerical simulation from the first step to the final excavation is performed. By analyzing and comparing the mechanical response and displacement changes of the servo steel addition on the hull, herringbone, and other supports in each analysis step, supports with better mechanical and displacement responses are selected with the goal of minimizing stress and displacement. Then, the selected supports are combined in pairs, and 4-5 axial force threshold combinations are set for each dual-servo steel scheme for simulation.

[0031] Step 4: Optimization and Output

[0032] Extract the maximum displacement and maximum stress values ​​of the shipwreck structure from all simulated working conditions, and conduct a comprehensive comparative analysis considering the stress and displacement of the fishbone and supports, selecting the working condition that optimizes the above indicators. Determine the support placement location corresponding to this working condition (e.g., ...). Figure 3 Example) The output is the optimal layout diagram. Figure 3 In this diagram, 11 represents the shipwreck, and 12 represents the steel support. For each support in this working condition, the axial force threshold at each excavation step is determined. The optimal axial force threshold for each support at different excavation stages is then obtained, forming a staged axial force threshold matrix as the core design outcome. The axial force threshold matrix is ​​a two-dimensional data table. Rows represent different excavation stages or depths, columns represent each servo steel support, and table element values ​​are the recommended axial force control thresholds for that support at the corresponding stage.

[0033] Although the present invention has been described in detail with reference to the foregoing embodiments, it is obvious that the described embodiments are merely preferred embodiments of the present invention, and not all embodiments. For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for optimizing the arrangement of servo steel supports based on the stress-coordinated response of the support system, characterized in that, Includes the following steps: Step 1: Establish a three-dimensional numerical model of the ancient ship-soil-support structure: Based on the three-dimensional scanning data of the archaeological site, construct a three-dimensional finite element model that includes the ancient shipwreck body, the surrounding and internal soil, and the existing support structure. Step 2: Identify key support areas: Based on the model established in Step 1, simulate the initial or typical excavation conditions, analyze the stress field and displacement field of the sunken ship structure, and identify stress concentration areas and areas with large displacement as potential key points for the deployment of servo steel supports. Step 3: Determine the servo support layout and axial force optimization scheme: Set multiple spatial layout schemes for servo steel supports and their corresponding axial force threshold combinations, simulate the complete excavation process one by one in the numerical model, and compare and analyze the control effects of different schemes on the displacement and stress of the shipwreck structure. Step 4: Output optimal support parameters: With the goal of minimizing the deformation and stress of the sunken ship structure, the optimal servo steel support spatial arrangement scheme is selected from the simulation results of Step 3, and the optimal axial force threshold of each support at different excavation stages is determined to form a staged axial force threshold matrix.

2. The servo steel support optimization arrangement method based on the stress-coordinated response of the support system according to claim 1, characterized in that: In step 1, the model of the ancient shipwreck body adopts a transversely isotropic elastic constitutive model, which is obtained by inversion of monitoring data.

3. The servo steel support optimization arrangement method based on the stress-coordinated response of the support system according to claim 1, characterized in that: In step 1, the soil model adopts the Mohr-Coulomb model.

4. The servo steel support optimization arrangement method based on the stress-coordinated response of the support system according to claim 1, characterized in that: In step 2, stress concentration areas and areas with large displacements are identified in the hull, supports, and fish skeleton, respectively.

5. The servo steel support optimization arrangement method based on the stress-coordinated response of the support system according to claim 1, characterized in that: In step 3, the mechanical behavior of the servo steel support in the numerical model is simplified as follows: when the absolute value of the support axial force is less than a preset threshold, it behaves as a linear spring; when the axial force reaches the preset threshold, the axial force is kept constant at the threshold level.

6. The servo steel support optimization arrangement method based on the stress-coordinated response of the support system according to claim 1, characterized in that: The axial force threshold matrix is ​​a two-dimensional data table. The rows represent different excavation stages or depths, the columns represent each servo steel support, and the table element values ​​are the recommended axial force control thresholds for the corresponding support at the corresponding stage.

Images