Dynamic risk assessment method and device for steel cofferdam construction period based on digital twin

Abstract

The present application provides a method and device for dynamic risk assessment during the construction period of a steel cofferdam based on digital twins, including: based on the constructed dynamic risk assessment index system, using a real-time dynamic monitoring and acquisition system to collect the actual values ​​of each monitoring point corresponding to each evaluation index in the initial state and the current state; using the steel cofferdam digital twin model combined with finite element calculation to obtain the theoretical values ​​of each monitoring point in the initial state and the current state; calculating the actual change value and theoretical change value of each monitoring point; determining the alarm value of each evaluation index and the predicted stress of the component under the most unfavorable working condition based on the actual change value and the theoretical change value, and performing risk assessment, the actual value of any evaluation index is the sum of the actual value of the corresponding monitoring point in the current state and the theoretical value in the initial state. By using a digital twin system combined with on-site measured data, the current risk level can be accurately assessed so that the structural stiffness can be adjusted in time or backwater can be carried out in the weir in advance to ensure structural safety.

Description

Technical Field

[0001] The present application belongs to the technical field of deepwater bridge foundation construction, and in particular, relates to a method and device for dynamic risk assessment during the steel cofferdam construction period based on digital twins. Background Art

[0002] In recent years, with the development of my country's economy, the construction of supporting transportation infrastructure has been accelerated, and large-span bridges across rivers and seas have emerged. Building large-sized pedestal foundations in rivers with deep water levels, turbulent water flows, and undulating riverbed terrain has become a major problem faced by bridge builders. Double-walled steel cofferdams, as water retaining structures for pedestal construction, have been widely used in the construction of deep-water river bridge foundations in recent years. However, the risks brought about by the complexity and uncertainty of its construction technology have also caused huge adverse consequences such as casualties, economic losses, and delays in construction period. A comprehensive, effective, and timely risk assessment system is established for double-walled steel cofferdams during the construction period to ensure safety and reliability during the construction of steel cofferdams.

[0003] During the construction of deep-water foundations, the steel cofferdam needs to be monitored according to the specifications. In traditional monitoring methods, the maximum construction water level in finite element technology is often used as the control stress of the structure, which results in data isolation compared with the measured data. In actual construction, there are dynamic water flow pressure, uneven heating, depreciation of rod materials, coupling and constraint relationships between rods. Therefore, the finite element calculation model in the design cannot be used directly, and appropriate corrections should be considered. The data accuracy is insufficient. The actually monitored stress, displacement, etc. can only judge the risk level of the current measured data, but cannot effectively infer the risk level under the most unfavorable working conditions in the future, posing a major safety hazard. Summary of the invention

[0004] The main purpose of the embodiments of the present invention is to provide a dynamic risk assessment method and device for steel cofferdam construction based on digital twins. By adopting a digital twin system combined with on-site measured data, the current risk level can be accurately assessed so as to adjust the structural stiffness in time or carry out backflow in the weir in advance to ensure structural safety.

[0005] In a first aspect, a dynamic risk assessment method for a steel cofferdam construction period based on digital twin is provided, the method comprising: determining evaluation indicators for the steel cofferdam construction period, and constructing a dynamic risk assessment indicator system for the steel cofferdam construction period; applying a real-time dynamic monitoring and acquisition system based on the dynamic risk assessment indicator system to respectively collect actual values ​​of each monitoring point corresponding to each evaluation indicator in the initial state and the current state; obtaining steel cofferdam parameters and environmental parameters in the initial state and the current state, and applying a steel cofferdam digital twin model combined with finite element calculation based on the cofferdam parameters and the environmental parameters to respectively obtain theoretical values ​​of each monitoring point in the initial state and the current state; calculating the difference between the actual value of each monitoring point in the current state and the actual value in the initial state to obtain the actual change value, and calculating the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value; determining the alarm value of the evaluation indicator corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition according to the actual change value and the theoretical change value of each monitoring point, and performing risk assessment according to the actual value, predicted stress and alarm value of each evaluation indicator, the actual value of any evaluation indicator is the sum of the actual value of the monitoring point corresponding to the evaluation indicator in the current state and the theoretical value in the initial state.

[0006] In another possible implementation, the evaluation indicators for the steel cofferdam construction period are determined, and a dynamic risk assessment indicator system for the steel cofferdam construction period is constructed, including: combining the construction method and risk analysis of the double-wall steel cofferdam, selecting the weir top displacement, lowering system, and cofferdam strength in the required measurement items as the first-level evaluation indicators for dynamic risk analysis; for other evaluation indicators other than the first-level evaluation indicators, the corresponding evaluation indicators of the next level are determined according to the measurement content of each evaluation indicator in the previous level evaluation indicator; combining the relationship between all evaluation indicators at all levels, establishing a hierarchical structure of the steel cofferdam dynamic risk assessment indicator system; processing the importance scores of the dynamic factor indicators during the steel cofferdam construction period according to expert experience to obtain a judgment matrix; calculating the weight value of each evaluation indicator at the corresponding level according to the judgment matrix, and performing a consistency test to obtain the final weight value of each evaluation indicator at the corresponding level; combining the hierarchical structure and the weight values ​​of the evaluation indicators at each level at the corresponding level to obtain the dynamic risk assessment indicator system for the steel cofferdam construction period.

[0007] In one possible implementation, a risk assessment is performed based on the actual value of each evaluation index, the predicted stress, and the alarm value, including: if the predicted stress is less than or equal to the alarm value, the steel cofferdam structure is determined to be safe, and the dangerous period of the highest water level is smoothly transitioned by reinforcing the structural rods in advance or stopping the construction in advance before the highest water level arrives, and injecting water into the weir; if the predicted stress is greater than the alarm value, an early warning reminder is provided through the early warning mechanism, and the stiffness and stability of the structural member are strengthened through reinforcement and other measures at a later stage.

[0008] In another possible implementation, the alarm value of the evaluation index corresponding to the monitoring point is determined according to the actual change value and the theoretical change value of each monitoring point, including: calculating the difference between the actual change value and the theoretical change value of each monitoring point; if the difference exceeds a preset threshold, cyclically adjusting the step size between the initial state and the current state, obtaining the actual value and the theoretical value under each state based on the step size, and adjusting the finite element parameters of the digital twin model of the steel cofferdam according to the actual value and the theoretical value under each state until the difference is less than the preset threshold; if the difference is less than the preset threshold, comparing the actual change value with the theoretical change value, and determining the alarm value of the evaluation index corresponding to the monitoring point according to the comparison result.

[0009] In another possible implementation, the step size between the initial state and the current state is cyclically adjusted to obtain the actual value and the theoretical value under each state, and the finite element parameters of the digital twin model of the steel cofferdam are adjusted according to the actual value and the theoretical value under each state until the difference is less than a preset threshold, including: selecting the first step size as the current step size; obtaining the actual value and the theoretical value under each state after the initial state with the current step size; fitting the change curves of the actual value and the theoretical value according to the actual value and the theoretical value under each state; optimizing and adjusting the finite element parameters of the digital twin model of the steel cofferdam according to the fitted change curves of the actual value and the theoretical value to obtain the adjusted digital twin model of the steel cofferdam; calculating the difference based on the adjusted digital twin model of the steel cofferdam; if the difference still exceeds the preset threshold, selecting the second step size that is smaller than the first step size as the current step size, and cyclically repeating the above steps until the difference is less than the preset threshold.

[0010] In another possible implementation, the alarm value of the evaluation index corresponding to the monitoring point is determined according to the comparison result, including: if the actual change value is less than or equal to the theoretical change value, then the actual unacceptable value of any evaluation index is determined to be the difference between the theoretical unacceptable value and the theoretical value of the corresponding monitoring point under the initial state, the alarm value of the evaluation index is 85% of the actual unacceptable value, the predicted stress of the component under the most unfavorable working condition is the stress value of each component under the most unfavorable working condition obtained by performing finite element analysis on the digital twin model of the steel cofferdam, wherein the theoretical unacceptable value of any evaluation index is the design value of the component material or the displacement limit required by the specification, and the theoretical value of the corresponding monitoring point under the initial state is the initial stress or displacement generated by the component when the monitoring equipment is installed; if the actual change value is greater than the theoretical change value, the safety factor of any evaluation index is determined. K is the ratio of the actual change value to the theoretical change value, and the actual unacceptable value of the evaluation index is determined as X si -KB 0iThe alarm value of the evaluation index is 85% of the actual unallowable value. The predicted stress of the component under the most unfavorable working condition is the stress value and safety factor of each component under the most unfavorable working condition obtained by finite element analysis using the digital twin model of the steel cofferdam. K The product of X si is the theoretically unacceptable value of the evaluation index, B 0i is the theoretical value of the corresponding monitoring point under the initial state.

[0011] In another possible implementation, performing risk assessment according to the actual value, predicted stress, and alarm value of each evaluation indicator further includes: calculating the efficacy coefficient value of each evaluation indicator by applying the following relationship according to the actual value and the unallowable value of each evaluation indicator:

[0012] ,or

[0013]

[0014] in, d i For the i The efficacy coefficient value of the evaluation index is B 0i is the theoretical value under the initial state, X si For the i The unacceptable values ​​of the evaluation indicators are K is the safety factor, X i For the i The actual value of the evaluation index.

[0015] In the second aspect, a dynamic risk assessment device for the steel cofferdam construction period based on digital twin is provided, and the device includes: an indicator system construction module, which is used to determine the evaluation indicators of the steel cofferdam construction period and construct a dynamic risk assessment indicator system for the steel cofferdam construction period; a data acquisition module, which is used to apply a real-time dynamic monitoring and acquisition system based on the dynamic risk assessment indicator system to collect the actual values ​​of each monitoring point corresponding to each evaluation indicator in the initial state and the current state respectively; a finite element calculation module, which is used to obtain the steel cofferdam parameters and environmental parameters in the initial state and the current state, and apply the steel cofferdam digital twin model combined with finite element calculation based on the cofferdam parameters and environmental parameters to obtain the initial state and the current state respectively. Theoretical value of each monitoring point under the state; a calculation module, used to calculate the difference between the actual value of each monitoring point in the current state and the actual value in the initial state to obtain the actual change value, and calculate the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value; a risk assessment module, used to determine the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition according to the actual change value and the theoretical change value of each monitoring point, and perform risk assessment according to the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

[0016] In a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, a dynamic risk assessment method for the steel cofferdam construction period based on digital twins as provided in the first aspect is implemented.

[0017] In a fourth aspect, a non-transitory computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, a dynamic risk assessment method for the steel cofferdam construction period based on digital twins as provided in the first aspect is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in describing the embodiments of the present application are briefly introduced below.

[0019] Figure 1 A flowchart of a method for dynamic risk assessment during steel cofferdam construction based on digital twins provided in one embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a dynamic risk assessment indicator system provided by an embodiment of the present invention;

[0021] Figure 3 A structural diagram of a dynamic risk assessment device for steel cofferdam construction period based on digital twins provided by one embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the physical structure of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present invention.

[0024] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, modules and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, modules, components and / or groups thereof. It should be understood that when we refer to a module as being "connected" or "coupled" to another module, it may be directly connected or coupled to the other modules, or there may be intermediate modules. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any modules and all combinations of one or more associated listed items.

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation method of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0026] The technical solution of the present application and how to solve the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0027] Digital twin technology is a new technology that integrates basic digitalization, Internet of Things, Building Information Modeling (BIM), big data, and artificial intelligence. It can combine the physical world with the virtual world through the precise perception of IoT devices, the real feedback of BIM models, powerful algorithm support, and convenient interactive experience. It can digitally simulate the water level, stress, displacement and other data information in the real world, and simulate and analyze them in a virtual environment, adjust and optimize the state and conditions of the twin model in real time, and guide the on-site construction through the adjusted calculation results. This application adopts a digital twin system to dynamically adjust the BIM model, environmental parameters, loads and boundary parameters of the steel cofferdam in real time according to actual conditions. By comparing with the automatically collected monitoring data, the finite element calculation model is optimized, and more accurate finite element parameters such as soil spring stiffness and node constraint stiffness are fitted, the initial stress is corrected, and the alarm value is optimized. Combined with the on-site measured data, the current risk level is accurately evaluated; and according to the most unfavorable working conditions or the most unfavorable water level in the future, the risk level at the most unfavorable working conditions or the most unfavorable water level in the future is deduced, and the structural stiffness is adjusted in time or the backwater in the weir is carried out in advance to ensure the safety of the structure.

[0028] like Figure 1 The figure is a flow chart of a method for dynamic risk assessment of steel cofferdam construction period based on digital twins provided by an embodiment of the present invention, the method comprising:

[0029] Step S11, determining the evaluation index during the steel cofferdam construction period, and constructing a dynamic risk assessment index system during the steel cofferdam construction period.

[0030] Step S12, based on the dynamic risk assessment indicator system, a real-time dynamic monitoring and collection system is used to collect actual values ​​of each monitoring point corresponding to each evaluation indicator in the initial state and the current state.

[0031] Step S13, obtaining the steel cofferdam parameters and environmental parameters in the initial state and the current state, and applying the steel cofferdam digital twin model combined with finite element calculation based on the cofferdam parameters and the environmental parameters to obtain the theoretical values ​​of each monitoring point in the initial state and the current state respectively.

[0032] Step S14, calculating the difference between the actual value of each monitoring point in the current state and the actual value in the initial state to obtain the actual change value, and calculating the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value.

[0033] Step S15, determine the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition according to the actual change value and the theoretical change value of each monitoring point, and perform risk assessment according to the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

[0034] The embodiment of the present invention adopts a digital twin system in combination with on-site measured data to accurately assess the current risk level, so as to timely adjust the structural stiffness or carry out water return in the weir in advance to ensure structural safety.

[0035] In an embodiment of the present invention, in step S11, optionally, in combination with the construction method and risk analysis of the double-wall steel cofferdam, the weir top displacement, the lowering system, and the cofferdam strength in the required measurement items are selected as the first-level evaluation indicators for dynamic risk analysis; for evaluation indicators other than the first-level evaluation indicators, the corresponding evaluation indicators of the next level are determined according to the measurement content of each evaluation indicator in the previous level evaluation indicator; in combination with the relationship between all levels of evaluation indicators, a hierarchical structure of the dynamic risk assessment index system for steel cofferdams is established; the importance scores of the dynamic factor indicators during the construction period of the steel cofferdam are processed according to expert experience to obtain a judgment matrix; the weight values ​​of each evaluation indicator are calculated according to the judgment matrix, and a consistency test is performed to obtain the final weight values ​​of each indicator; the hierarchical structure and the weight values ​​of the evaluation indicators at the corresponding levels are combined to obtain the dynamic risk assessment index system for the construction period of the steel cofferdam.

[0036] In the embodiment of the present invention, the dynamic risk assessment index system of steel cofferdam is divided into two levels of evaluation indicators including level 1 evaluation indicators and level 2 evaluation indicators as an example for explanation. According to the "Steel Cofferdam Engineering Technical Standards", combined with the double-wall steel cofferdam construction method and risk analysis, the mandatory items of weir top displacement, lowering system, and cofferdam strength are selected as the level 1 indicators of dynamic risk analysis. According to the measurement content of the level 1 indicators, they are further subdivided as level 2 indicators. Combined with the mutual relationship between the indicators at each level, a hierarchical structure diagram of the level 2 evaluation index system of the dynamic risk of steel cofferdam is established, as shown in FIG. Figure 2 As shown, it includes three level 1 evaluation indicators: weir top displacement, lowering system and cofferdam strength. The level 1 evaluation indicator weir top displacement includes two level 2 evaluation indicators: cofferdam top plane displacement and cofferdam top vertical displacement. The level 1 evaluation indicator lowering system includes one level 2 evaluation indicator: steel plate beam stress. The level 1 evaluation indicator cofferdam strength includes three level 2 evaluation indicators: weir wall stress, inner wall deflection and overall inclination.

[0037] Firstly, the probability statistics method is used to assign initial weights to the static risk factors and normalize them to obtain the static weights of each static risk factor. Specifically, the probability statistics method is used to assign weight values ​​to the static risk factors at all levels, and the level 1 and level 2 indicators in the static risk factors of the steel cofferdam are normalized respectively. The comprehensive table of the weight distribution of static risk factors is shown in Table 1.

[0038] Table 1 Comprehensive table of static risk factor weight distribution

[0039]

[0040] Then, the relative importance of each evaluation index of the next level relative to each evaluation index of the previous level is calculated by using the hierarchical analysis method according to the static weight, and the judgment matrix is ​​constructed in combination with expert experience. Specifically, the hierarchical analysis method is used to calculate the relative importance of each layer element relative to the adjacent previous layer element, and the importance of the dynamic factor index of the steel cofferdam construction period is compared pairwise according to the above-mentioned dynamic factor index (i.e., evaluation index) during the steel cofferdam construction period, and the importance of the dynamic factor index during the steel cofferdam construction period is divided according to the importance level shown in Table 2.

[0041] Table 2 Importance classification scale

[0042]

[0043] The expert scoring method was used to process the importance scores of the dynamic factor indicators (i.e., evaluation indicators) during the steel cofferdam construction period from 10 experts to obtain the judgment matrix, as shown in Table 3 below.

[0044] Table 3 Dynamic factor index judgment matrix during steel cofferdam construction period

[0045]

[0046] The weight values ​​of each evaluation index at the corresponding level are calculated according to the judgment matrix, and the consistency test is performed to obtain the final weight values ​​of each evaluation index at the corresponding level. Specifically, the expert scoring method is adopted, and the importance scores of the dynamic factor indicators during the construction period of the steel cofferdam are processed by 10 experts to obtain the judgment matrix. The weight values ​​of the influencing factors (i.e., evaluation indicators) at each level are calculated according to the judgment matrix. For example, the weight values ​​of each evaluation index at the corresponding level are shown in Table 4 below.

[0047] Table 4 Weight values ​​of each evaluation index

[0048]

[0049] In the embodiment of the present invention, according to the monitoring scheme, a real-time dynamic monitoring and acquisition system is installed to obtain the initial state X 0 The corresponding monitoring points iThe actual value of A 0i .

[0050] Obtain the steel cofferdam parameters, internal and external water levels, geological conditions, soil layer height, temperature and other environmental parameters in the initial state, and accurately restore the initial state by establishing a digital twin model of the steel cofferdam X 0 The physical model and environment of the steel cofferdam under the finite element calculation are used to obtain the initial state. X 0 The following monitoring points i Theoretical value B 0i .

[0051] Automatically obtain the current status X 1 The steel cofferdam parameters and environmental parameters under the current state are automatically adjusted through the digital twin, including load conditions, boundary conditions, BIM models and other basic parameters, to obtain the current state X 1 The following monitoring points i Theoretical value B 1i , and calculate the current status of each monitoring point X 1 Theoretical value of B 1i With the initial state X 0 The following monitoring points i Theoretical value B 0i The difference is obtained for each monitoring point i Theoretical change value .

[0052] Automatically obtain the current status X 1 The following monitoring points i The actual value of A 1i , and calculate each monitoring point i Current status X 1 The actual value of A 1i With the initial state X 0 The actual value of A 0i The difference between the monitoring points i The actual change in .

[0053] In step S15, firstly, the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition are determined according to the actual change value and the theoretical change value of each monitoring point.

[0054] In the embodiment of the present invention, the finite element calculation parameters (BIM model, environmental parameters, load and boundary parameters, etc.) in the digital twin model are optimized through a multi-layer iteration method. By comparing with the automatically collected monitoring data, the finite element calculation model is optimized, and more accurate finite element parameters such as soil spring stiffness and node constraint stiffness are fitted to correct the initial stress, which provides a basis for obtaining the accurate alarm value of each rod in the future. According to the initial stress obtained above, the alarm value of the evaluation index corresponding to the monitoring point can be obtained.

[0055] Optionally, calculate the actual change value of each monitoring point Theoretical change value The difference.

[0056] If the difference exceeds the preset threshold, the step size between the initial state and the current state is adjusted cyclically, the actual value and theoretical value under each state are obtained based on the step size, and the finite element parameters of the digital twin model of the steel cofferdam are adjusted according to the actual value and theoretical value under each state until the difference is less than the preset threshold. Optionally, the first step size is selected as the current step size; the actual value and theoretical value under each state after the initial state are obtained with the current step size; the change curves of the actual value and theoretical value are fitted according to the actual value and theoretical value under each state; the finite element parameters of the digital twin model of the steel cofferdam are optimized and adjusted according to the fitted change curves of the actual value and theoretical value to obtain the adjusted digital twin model of the steel cofferdam; the difference is calculated based on the adjusted digital twin model of the steel cofferdam; if the difference still exceeds the preset threshold, the second step size smaller than the first step size is selected as the current step size, and the aforementioned steps are repeated cyclically until the difference is less than the preset threshold. The preset threshold can be set as needed, preferably 10%.

[0057] If the actual change value Theoretical change value If the difference exceeds 10%, it is considered that the state and parameters of the theoretically calculated steel cofferdam digital twin model and the actual monitored physical model are deviated. X 0 The next 3-5 working conditions are the first step, for example, the initial state X 0 The installation state of the steel cofferdam purlin is selected as the state of the purlin lowered and tightened. X 1 , when the soil depth is 1 meter X 2 , when the soil depth is 2m X 3Collect the steel cofferdam parameters, environmental parameters, internal and external water level parameters, etc. in various states, obtain the digital twin model of the steel cofferdam in various states, fit the change curve of the theoretical value and the measured value under 3-5 working conditions, optimize and adjust the finite element parameters such as the compression spring stiffness in the digital twin model of the steel cofferdam, so that the actual change value Theoretical change value The difference is within 10%.

[0058] if and The difference is still more than 10%, so the initial state can be selected X 0 The second step after that, for example, the initial state X 0 The installation state of the steel cofferdam purlin is selected as the purlin lowering state. X 1 , the top tight state is X 2 , when the soil depth is 0.5 meters X 3 , when the soil depth is 1m X 4 etc., refine the adjustment step size, and further optimize and adjust the finite element parameters such as the compression spring stiffness in the digital twin model of the steel cofferdam so that the actual change value Theoretical change value The difference is within 10%. and If the difference is still more than 10%, further refine the working conditions to obtain the third-order step size, and so on. Theoretical change value The difference is within 10%.

[0059] If the difference is less than the preset threshold, the actual change value is compared and theoretical change value and determine the alarm value of the evaluation index corresponding to the monitoring point based on the comparison result.

[0060] Optional, if the actual change value Less than or equal to the theoretical change value , then the actual unacceptable value of any evaluation index is determined to be the difference between the theoretical unacceptable value and the theoretical value of the corresponding monitoring point under the initial state. The alarm value of the evaluation index is 85% of the actual unacceptable value. The predicted stress of the component under the most unfavorable working condition is the stress value of each component under the most unfavorable working condition obtained by finite element analysis using the steel cofferdam digital twin model. Among them, the theoretical unacceptable value of any evaluation index is the displacement limit value required by the component material design value or the specification, and the theoretical value of the corresponding monitoring point under the initial state is the initial stress or displacement generated by the component when the monitoring equipment is installed. If the actual change value Less than or equal to the theoretical change value It can be considered that the actual stiffness of the structure is greater than that simulated by the digital twin, and the structure is relatively safe. The stress values ​​of each component under the most unfavorable working condition obtained by finite element analysis using the digital twin model of the steel cofferdam can be directly applied. B mi , as the predicted stress of the component under the most unfavorable working condition. The alarm value of the evaluation index is 0.85 ( X si -B 0i ).

[0061] If the actual change value Greater than the theoretical change , then determine any evaluation index i Safety factor K The ratio of the actual change value to the theoretical change value is used to determine the evaluation index i The actual allowed value is Xsi-KB 0i , evaluation index i The alarm value is 85% of the actual unallowable value. The predicted stress of the component under the most unfavorable working condition is obtained by using the finite element analysis of the steel cofferdam digital twin model to obtain the stress value and safety factor of each component under the most unfavorable working condition. K The product of X si For evaluation indicators i Theoretically not allowed values, B 0i is the corresponding monitoring point in the initial state i Theoretical value. If the actual change value Greater than the theoretical change , it can be considered that the actual stiffness of the structure is greater than the stiffness simulated by the digital twin, and the structure is unsafe, so the safety factor is taken , the stress values ​​of each component under the most unfavorable working condition obtained by finite element analysis B mi Multiply by the safety factor K As the prediction stress, the evaluation index i The alarm value is 0.85 ( Xsi -KB 0i ).

[0062] After calculating the predicted stress and the alarm value of each evaluation index, risk assessment is performed based on the actual value of each evaluation index, the predicted stress and the alarm value.

[0063] Optionally, if the predicted stress is less than or equal to the alarm value, the steel cofferdam structure is determined to be safe, and the structural members can be reinforced in advance or the construction can be stopped in advance before the highest water level arrives, and water can be injected into the weir to smoothly transition to the dangerous period of the highest water level. The predicted stress is less than or equal to the alarm value means: the actual change value Less than or equal to the theoretical change value Predicted stress B mi Less than or equal to 0.85 ( X si -B 0i ), or the actual change value Greater than the theoretical change Predicted stress KB mi Less than or equal to 0.85 ( X si -KB 0i ). This indicates that the predicted stress of the component under the most unfavorable future working condition is less than the alarm value. The structural safety can be ensured by reinforcing the structural members in advance or stopping the construction in advance before the highest water level arrives, and injecting water into the weir to smoothly transition to the dangerous period of the highest water level.

[0064] If the predicted stress is greater than the alarm value, an early warning reminder will be provided through the early warning mechanism, and reinforcement and other measures will be taken later to strengthen the stiffness and stability of the structural components. The predicted stress is greater than the alarm value means: the actual change value Less than or equal to the theoretical change value Predicted stress B mi Greater than 0.85 ( X si -B 0i ), or the actual change value Greater than the theoretical change Predicted stress KB mi Greater than 0.85 ( X si -KB 0i ). This indicates that the predicted stress of the component will exceed the alarm value under the most unfavorable working condition. An early warning reminder should be provided through the early warning mechanism, and the stiffness and stability of the structural component should be strengthened through reinforcement and other measures in the later stage.

[0065] In the embodiment of the present invention, risk assessment is performed based on the actual value, predicted stress and alarm value of each evaluation indicator, and also includes: the actual change value Theoretical change value When the difference is within 10%, the dynamic risk assessment model adopts the efficacy coefficient evaluation model, and calculates the total efficacy coefficient value of the dynamic risk assessment according to the evaluation index system established previously and the weights of each evaluation index obtained. Optionally, first calculate the efficacy coefficient value of each evaluation index according to the actual value and the unallowed value of each evaluation index using the following relationship:

[0066] ,or

[0067]

[0068] in, d i For the i The efficacy coefficient value of the evaluation index is X si For the i The unacceptable value of the evaluation index, K is the safety factor, X i For the i The actual value of the evaluation index is the current state X 1 The actual values ​​of each monitoring point under A 1i Compared with the theoretical value under the initial state B 0i The sum of X i =A 1i +B 0i 0.85( X si -B 0i ) and 0.85 ( X si -KB 0i ) is the precise alarm value determined previously.

[0069] Then, based on the dynamic risk assessment indicator system, the total efficacy coefficient value of the dynamic risk assessment is calculated according to the efficacy coefficient value and weight value of each evaluation indicator:

[0070]

[0071] in, D is the total efficacy coefficient, ω i For the iThe normalized weight coefficient of the evaluation index is calculated. At this point, it can be considered that the digital twin model is consistent with the actual physical model.

[0072] The calculated total power coefficient is used as the comprehensive evaluation safety value of the dynamic risk during the construction period of the double-wall steel cofferdam. The size of the safety value reflects the risk level of the current construction status. The larger the value, the smaller the risk and the higher the safety during the construction of the double-arm steel cofferdam. According to the size of the safety value, the corresponding safety value interval is divided into five risk levels: safe, low risk, medium risk, high risk, and extremely high risk, as shown in Table 5. When the safety value is lower than 60 points or the dynamic risk index exceeds the warning value, the double-wall steel cofferdam is in an extremely dangerous state, and the construction needs to be stopped, the cause needs to be found out, and measures need to be taken to eliminate the influencing factors before the construction can continue.

[0073] Table 5 Dynamic risk level classification

[0074]

[0075] The embodiment of the present invention adopts a digital twin system, which can dynamically adjust the BIM model, environmental parameters, loads and boundary parameters of the steel cofferdam in real time according to actual conditions. By comparing with the automatically collected monitoring data, the finite element calculation model is optimized, and more accurate finite element parameters such as soil spring stiffness and node constraint stiffness are fitted, the initial stress is corrected, and the alarm value is optimized. Combined with the on-site measured data, the current risk level is accurately evaluated; and according to the most unfavorable working conditions or the most unfavorable water levels in the future, the risk level under the most unfavorable working conditions or the most unfavorable water levels in the future is deduced, and the structural stiffness is adjusted in time or backflow in the weir is carried out in advance to ensure the safety of the structure.

[0076] In summary, the embodiment of the present invention determines the evaluation index of the steel cofferdam construction period and constructs a dynamic risk assessment index system for the steel cofferdam construction period; based on the dynamic risk assessment index system, a real-time dynamic monitoring and acquisition system is used to respectively collect the actual values ​​of each monitoring point corresponding to each evaluation index in the initial state and the current state; the steel cofferdam parameters and environmental parameters in the initial state and the current state are obtained, and based on the cofferdam parameters and the environmental parameters, a steel cofferdam digital twin model is applied in combination with finite element calculation to respectively obtain the theoretical values ​​of each monitoring point in the initial state and the current state; the difference between the actual value of each monitoring point in the current state and the actual value in the initial state is calculated to obtain the actual change value , calculate the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value; determine the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition according to the actual change value and the theoretical change value of each monitoring point, and perform risk assessment based on the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state. By using the digital twin system combined with the on-site measured data, the current risk level can be accurately assessed so that the structural stiffness can be adjusted in time or backwater can be carried out in the weir in advance to ensure structural safety.

[0077] like Figure 3 The figure shows a structural diagram of a dynamic risk assessment device for steel cofferdam construction period based on digital twins provided by an embodiment of the present invention, the device comprising:

[0078] An indicator system construction module 301 is used to determine the evaluation indicators during the steel cofferdam construction period and to construct a dynamic risk assessment indicator system during the steel cofferdam construction period;

[0079] The data collection module 302 is used to collect the actual values ​​of each monitoring point corresponding to each evaluation index in the initial state and the current state respectively by using the real-time dynamic monitoring collection system based on the dynamic risk assessment index system;

[0080] The finite element calculation module 303 is used to obtain the steel cofferdam parameters and environmental parameters in the initial state and the current state, and apply the steel cofferdam digital twin model combined with the finite element calculation based on the cofferdam parameters and the environmental parameters to obtain the theoretical values ​​of each monitoring point in the initial state and the current state respectively;

[0081] The calculation module 304 is used to calculate the difference between the actual value of each monitoring point in the current state and the actual value in the initial state to obtain the actual change value, and calculate the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value;

[0082] The risk assessment module 305 is used to determine the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition based on the actual change value and the theoretical change value of each monitoring point, and to perform risk assessment based on the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

[0083] The device of the above embodiment is applied to the corresponding method in the above embodiment, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0084] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4 As shown, the electronic device may include: a processor (processor) 401, a communication interface (Communications Interface) 402, a memory (memory) 403 and a communication bus 404, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. The processor can call the logic instructions in the memory to execute a dynamic risk assessment method for the steel cofferdam construction period based on digital twins, the method comprising: determining the evaluation index of the steel cofferdam construction period, and constructing a dynamic risk assessment index system for the steel cofferdam construction period; based on the dynamic risk assessment index system, applying a real-time dynamic monitoring and acquisition system to respectively collect the actual values ​​of each monitoring point corresponding to each evaluation index in the initial state and the current state; obtaining the steel cofferdam parameters and environmental parameters in the initial state and the current state, and applying the steel cofferdam digital twin model combined with finite element calculation based on the cofferdam parameters and environmental parameters to respectively obtain the initial state and the current state. The theoretical value of each monitoring point in the current state; the difference between the actual value of each monitoring point in the current state and the actual value in the initial state is calculated to obtain the actual change value, and the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state is calculated to obtain the theoretical change value; according to the actual change value and the theoretical change value of each monitoring point, the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition are determined, and risk assessment is performed based on the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

[0085] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the 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 several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0086] On the other hand, an embodiment of the present invention further provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute a dynamic risk assessment method for a steel cofferdam construction period based on digital twins provided by the above-mentioned method embodiments, the method including: determining evaluation indicators for the steel cofferdam construction period, and constructing a dynamic risk assessment indicator system for the steel cofferdam construction period; based on the dynamic risk assessment indicator system, applying a real-time dynamic monitoring and acquisition system to respectively collect the actual values ​​of each monitoring point corresponding to each evaluation indicator in the initial state and the current state; obtaining steel cofferdam parameters and environmental parameters in the initial state and the current state, and based on The digital twin model of steel cofferdam combined with finite element calculation is applied to the cofferdam parameters and environmental parameters to obtain the theoretical values ​​of each monitoring point in the initial state and the current state respectively; the difference between the actual value of each monitoring point in the current state and the actual value in the initial state is calculated to obtain the actual change value, and the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state is calculated to obtain the theoretical change value; according to the actual change value and the theoretical change value of each monitoring point, the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition are determined, and risk assessment is performed based on the actual value, predicted stress and alarm value of each evaluation indicator. The actual value of any evaluation indicator is the sum of the actual value of the monitoring point corresponding to the evaluation indicator in the current state and the theoretical value in the initial state.

[0087] On the other hand, an embodiment of the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute a dynamic risk assessment method for a steel cofferdam construction period based on digital twins provided in the above-mentioned embodiments, the method comprising: determining evaluation indicators for the steel cofferdam construction period, and constructing a dynamic risk assessment indicator system for the steel cofferdam construction period; based on the dynamic risk assessment indicator system, applying a real-time dynamic monitoring and acquisition system to respectively collect actual values ​​of each monitoring point corresponding to each evaluation indicator in the initial state and the current state; obtaining steel cofferdam parameters and environmental parameters in the initial state and the current state, and applying the steel cofferdam digital twin system based on the cofferdam parameters and environmental parameters. The twin model is combined with finite element calculation to obtain the theoretical value of each monitoring point in the initial state and the current state respectively; the difference between the actual value of each monitoring point in the current state and the actual value in the initial state is calculated to obtain the actual change value, and the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state is calculated to obtain the theoretical change value; according to the actual change value and the theoretical change value of each monitoring point, the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition are determined, and risk assessment is performed based on the actual value, predicted stress and alarm value of each evaluation index. The actual value of any evaluation indicator is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

[0088] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0089] The above is only a partial implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A dynamic risk assessment method for steel cofferdam construction period based on digital twin, characterized in that: The method comprises: Determine the evaluation indicators during the steel cofferdam construction period and build a dynamic risk assessment indicator system during the steel cofferdam construction period; Based on the dynamic risk assessment index system, a real-time dynamic monitoring and acquisition system is used to respectively collect the actual values ​​of each monitoring point corresponding to each evaluation index in the initial state and the current state; Obtaining steel cofferdam parameters and environmental parameters in an initial state and a current state, and applying a steel cofferdam digital twin model in combination with finite element calculation based on the cofferdam parameters and the environmental parameters to obtain theoretical values ​​of each monitoring point in an initial state and a current state, respectively; The difference between the actual value of each monitoring point in the current state and the actual value in the initial state is calculated to obtain the actual change value, and the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state is calculated to obtain the theoretical change value; The alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition are determined according to the actual change value and the theoretical change value of each monitoring point, and risk assessment is performed according to the actual value of each evaluation index, the predicted stress and the alarm value. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

2. The method according to claim 1, characterized in that The evaluation indexes for the steel cofferdam construction period are determined, and a dynamic risk assessment index system for the steel cofferdam construction period is constructed, including: Combined with the construction method and risk analysis of double-wall steel cofferdam, the displacement of the weir top, the lowering system and the cofferdam strength are selected as the first-level evaluation indicators of dynamic risk analysis. For evaluation indicators of other levels other than the first-level evaluation indicators, the corresponding evaluation indicators of the next level are determined according to the measurement content of each evaluation indicator in the previous-level evaluation indicators; Combined with the interrelationships among all levels of evaluation indicators, a hierarchical structure of the steel cofferdam dynamic risk assessment indicator system is established; According to the expert experience, the importance scores of the dynamic factor indicators during the steel cofferdam construction period are processed to obtain the judgment matrix; Calculate the weight value of each evaluation indicator at the corresponding level according to the judgment matrix, and perform consistency check to obtain the final weight value of each evaluation indicator at the corresponding level; The dynamic risk assessment index system during the steel cofferdam construction period is obtained by combining the hierarchical structure and the weights of the evaluation indicators at the corresponding levels.

3. The method according to claim 1, characterized in that The risk assessment is performed according to the actual value of each evaluation index, the predicted stress and the alarm value, including: If the predicted stress is less than or equal to the alarm value, the steel cofferdam structure is determined to be safe, and the dangerous period of the highest water level can be smoothly transitioned by reinforcing the structural components in advance or stopping the construction in advance before the highest water level arrives, and injecting water into the weir; If the predicted stress is greater than the alarm value, an early warning reminder is provided through the early warning mechanism, and reinforcement measures are taken later to enhance the stiffness and stability of the structural member.

4. The method according to claim 1, characterized in that The step of determining the alarm value of the evaluation index corresponding to the monitoring point according to the actual change value and the theoretical change value of each monitoring point includes: Calculate the difference between the actual change value and the theoretical change value of each monitoring point; If the difference exceeds a preset threshold, the step distance between the initial state and the current state is adjusted cyclically, the actual value and the theoretical value under each state are obtained, and the finite element parameters of the steel cofferdam digital twin model are adjusted according to the actual value and the theoretical value under each state until the difference is less than the preset threshold; If the difference is smaller than the preset threshold, the actual change value is compared with the theoretical change value, and the alarm value of the evaluation index corresponding to the monitoring point is determined according to the comparison result.

5. The method according to claim 4, characterized in that The cyclic adjustment of the step distance between the initial state and the current state, obtaining the actual value and the theoretical value under each state based on the step distance, and adjusting the finite element parameters of the steel cofferdam digital twin model according to the actual value and the theoretical value under each state until the difference is less than the preset threshold value, includes: Select the first step as the current step; Acquire actual values ​​and theoretical values ​​in each state after the initial state with the current step size; According to the actual value and theoretical value in each state, the variation curves of the actual value and the theoretical value are fitted respectively; Optimizing and adjusting the finite element parameters of the steel cofferdam digital twin model according to the fitted actual value and the variation curve of the theoretical value to obtain an adjusted steel cofferdam digital twin model; Calculating the difference based on the adjusted digital twin model of the steel cofferdam; If the difference still exceeds the preset threshold, a second step size smaller than the first step size is selected as the current step size, and the above steps are repeated cyclically until the difference is smaller than the preset threshold.

6. The method according to claim 4, characterized in that The step of determining the alarm value of the evaluation index corresponding to the monitoring point according to the comparison result includes: If the actual change value is less than or equal to the theoretical change value, the actual unallowable value of any evaluation index is determined to be the difference between the theoretical unallowable value and the theoretical value of the corresponding monitoring point under the initial state, the alarm value of the evaluation index is 85% of the actual unallowable value, the predicted stress of the component under the most unfavorable working condition is the stress value of each component under the most unfavorable working condition obtained by finite element analysis using the steel cofferdam digital twin model, wherein the theoretical unallowable value of any evaluation index is the design value of the component material or the displacement limit required by the specification, and the theoretical value of the corresponding monitoring point under the initial state is the initial stress or displacement generated by the component when the monitoring equipment is installed; If the actual change value is greater than the theoretical change value, then any evaluation index is determined i Safety factor K The evaluation index is determined as the ratio of the actual change value to the theoretical change value. i The actual allowed value is X si -KB 0i , the evaluation index i The alarm value is 85% of the actual unallowable value. The predicted stress of the component under the most unfavorable working condition is the stress value and safety factor of each component under the most unfavorable working condition obtained by finite element analysis using the steel cofferdam digital twin model. K The product of X si For the evaluation index i Theoretically not allowed values ​​of B 0i is the corresponding monitoring point in the initial state i Theoretical value.

7. The method according to claim 6, characterized in that The risk assessment according to the actual value of each evaluation index, the predicted stress and the alarm value also includes: According to the actual value and the unallowed value of each evaluation index, the efficacy coefficient value of each evaluation index is calculated using the following relationship: ,or in, d i For the i The efficacy coefficient value of the evaluation index is B 0i is the theoretical value under the initial state, X si For the i The unacceptable values ​​of the evaluation indicators are K is the safety factor, X i For the i The actual value of the evaluation index; Based on the dynamic risk assessment indicator system, the total efficacy coefficient value of the dynamic risk assessment is calculated according to the efficacy coefficient value and weight value of each evaluation indicator.

8. A dynamic risk assessment device for steel cofferdam construction period based on digital twin, characterized in that: The device comprises: The indicator system construction module is used to determine the evaluation indicators during the steel cofferdam construction period and to construct a dynamic risk assessment indicator system during the steel cofferdam construction period; A data acquisition module, used to collect actual values ​​of each monitoring point corresponding to each evaluation index in an initial state and a current state respectively using a real-time dynamic monitoring acquisition system based on the dynamic risk assessment index system; A finite element calculation module is used to obtain the steel cofferdam parameters and environmental parameters in the initial state and the current state, and based on the cofferdam parameters and the environmental parameters, a steel cofferdam digital twin model is applied in combination with finite element calculation to obtain theoretical values ​​of each monitoring point in the initial state and the current state respectively; A calculation module is used to calculate the difference between the actual value of each monitoring point in the current state and the actual value in the initial state to obtain the actual change value, and calculate the difference between the theoretical value of each monitoring point in the current state and the theoretical value in the initial state to obtain the theoretical change value; The risk assessment module is used to determine the alarm value of the evaluation index corresponding to the monitoring point and the predicted stress of the component under the most unfavorable working condition according to the actual change value and the theoretical change value of each monitoring point, and to perform risk assessment according to the actual value of each evaluation index, the predicted stress and the alarm value. The actual value of any evaluation index is the sum of the actual value of the monitoring point corresponding to the evaluation index in the current state and the theoretical value in the initial state.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, it implements a dynamic risk assessment method for steel cofferdam construction period based on digital twins as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, a dynamic risk assessment method for steel cofferdam construction period based on digital twin is implemented as described in any one of claims 1 to 7.

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