Analogue simulation method and device for underground foundation pit re-service reconstruction
By combining the two-point ray tracing method and the birth and death element method with multi-dimensional feature data for parameter inversion and dynamic simulation, the problem of large deviation in simulation results during the renovation and reuse of underground foundation pits in traditional methods has been solved, achieving more accurate simulation and safe and controllable construction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-31
AI Technical Summary
Existing technologies cannot accurately capture the dynamic changes of structures during the simulation of underground foundation pit renovation and reuse, resulting in significant deviations in simulation results that are difficult to meet the needs of actual engineering projects.
A two-point ray tracing method combined with multi-dimensional feature data was used to perform parameter inversion, and a finite element model containing multiple elements was established. Dynamic simulation analysis was performed using the birth and death element method, and combined with collaborative stress optimization design, the optimal demolition rate and buffer layer design parameters were obtained.
It significantly improves the accuracy of simulation results, ensures the safety and controllability of actual construction, and meets the actual needs of the project.
Smart Images
Figure CN121765809A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of geotechnical engineering and underground structure renovation technology, and specifically relates to a simulation method and device for the re-service renovation of underground foundation pits. Background Technology
[0002] As urbanization continues, urban development is gradually shifting from incremental expansion to stock optimization. A large number of underground projects that have reached their design service life, such as underground foundation pits, face an urgent need for renovation and reuse. However, the renovation and reuse process of underground foundation pits faces complex engineering geological conditions and the state of existing support structures, resulting in many technical challenges in practical applications. Therefore, it is usually necessary to simulate the renovation and reuse process of underground foundation pits to ensure the safety and controllability of actual construction.
[0003] Currently, conventional finite element method (FEM) simulation is commonly used in simulating the renovation and reuse of underground foundation pits. However, this traditional method cannot accurately capture the dynamic changes of the structure, resulting in significant deviations in the simulation results and failing to meet the needs of actual engineering projects. Specifically, due to the time-sensitive nature of geological parameters, the mechanical properties of soil layers change significantly over time. Traditional methods only use historical geological survey parameters for simulation, leading to large errors in the displacement prediction of existing support structures and making it impossible to accurately assess the structural safety during foundation pit renovation. Secondly, when performing parameter inversion based on monitoring data, traditional methods mostly focus on optimizing and updating single soil parameters or local stiffness, without integrating soil layer parameters and the damage state of existing support structures into a unified inversion framework. This makes it difficult for the inversion results to comprehensively and accurately reflect the foundation pit renovation process. The actual engineering conditions during the construction process cannot provide a reliable basis for design. In addition, the birth and death element technology used in conventional finite element simulation, although it can simulate the excavation and unloading process, cannot effectively retain the historical deformation field and material aging effect of the existing support structure. This can easily lead to significant deviations in the stress redistribution prediction during the support removal construction stage, resulting in insufficient assessment of the loss of the existing support structure and difficulty in accurately grasping the actual stress state of the support structure. Furthermore, the modeling process of traditional methods is mostly aimed at single-case conversion, making it difficult to achieve smooth switching of material constitutive relations and continuous inheritance of existing deformation fields at different construction stages. This results in the inability to accurately capture the dynamic changes of the structure during the simulation of foundation pit renovation. Therefore, a new simulation method for underground foundation pit renovation and reuse is urgently needed to solve the above problems. Summary of the Invention
[0004] To address the technical problems existing in the prior art, this invention provides a simulation method and apparatus for the re-service renovation of underground foundation pits, in order to solve the technical problem that traditional methods cannot accurately capture the dynamic changes of the structure during the simulation of underground foundation pit renovation and reuse, resulting in large deviations in the simulation results and making it difficult to meet the needs of actual engineering.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a simulation method for the re-service retrofitting of underground foundation pits, comprising: Acquire multidimensional feature data of the target foundation pit; the multidimensional feature data of the target foundation pit includes historical monitoring data, current status data of the foundation pit, and real-time monitoring data; The two-point ray tracing method was used to perform parameter inversion on the soil parameters and damage coefficients of the existing support structure of the target foundation pit by combining the multidimensional feature data of the target foundation pit. After regularization, the parameter inversion results were obtained. Based on the parameter inversion results, a finite element model of the target foundation pit is established using the finite element method and the element birth and death method. The finite element model of the target foundation pit includes existing support structure elements, soil elements, backfill concrete elements, and additional elements that share nodes with the existing support structure elements. The backfill concrete elements include backfill concrete occupant elements and backfill concrete formal elements. Based on the finite element model of the target foundation pit, the element activation and failure strategy of the birth and death element method is used to carry out dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit, and obtain the dynamic simulation results of the re-service construction. Based on the dynamic simulation results of re-service construction, a collaborative stress optimization design was carried out to obtain the optimal demolition rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system.
[0006] Furthermore, the historical monitoring data of the target foundation pit includes geological exploration data and historical construction records of the target foundation pit; the current status data of the target foundation pit includes current geological environment data and status data of existing support structures; and the real-time monitoring data of the target foundation pit includes real-time dynamic change data of the target foundation pit, including displacement, stress distribution, and strain data of the target foundation pit.
[0007] Furthermore, using the two-point ray tracing method, combined with the multidimensional feature data of the target foundation pit, the soil layer parameters of the target foundation pit are inverted during the process of parameter inversion. Based on the change in soil layer depth of the target foundation pit, the soil layer parameters of the target foundation pit are inverted according to the layered progressive inversion strategy.
[0008] Furthermore, the existing support structure units are given an elastoplastic constitutive model that considers the effects of material aging and cumulative damage, the soil units are given a soil Mohr-Coulomb constitutive model, the backfill concrete units are given a concrete damage plastic constitutive model, and the additional units that share nodes with the existing support structure units are given a linear elastic constitutive model with a preset elastic modulus.
[0009] Furthermore, the finite element model of the target foundation pit also includes transition layer elements between the existing support structure elements and the backfill concrete elements. The elastic modulus of the transition layer unit between the existing support structure unit and the backfill concrete unit decreases gradually from the existing support structure side of the target pit to the backfill concrete side after modification, according to the preset exponential decay law.
[0010] Furthermore, based on the finite element model of the target foundation pit, and utilizing the element activation and failure strategy of the birth and death element method, dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit is carried out to obtain the dynamic simulation results of the re-service construction. This process includes: The activation state of all elements in the finite element model of the target foundation pit is initialized; According to the construction progress of the pre-set excavation area in the target foundation pit, the activation state of the soil unit is set to failure step by step, and the activation state of the backfill concrete occupant unit is set to activation step by step. Through simulation, the simulation results of the excavation construction stage of the target foundation pit are obtained. According to the construction progress of backfilling concrete in the target foundation pit, the activation state of the formal unit of backfilling concrete is set to active level by level, and the activation state of the occupant unit of backfilling concrete is set to inactive level by level. Through simulation, the simulation results of the backfilling construction stage of the target foundation pit are obtained. A stress release strategy of graded unloading is adopted, and the internal forces of the existing support structure unit are gradually reduced according to the preset time history, so that the lateral load on the existing support structure unit is transferred to the backfill concrete formal unit. The simulation results of the target pit support removal construction stage are obtained through simulation solution. The simulation results of the target foundation pit excavation construction stage, the target foundation pit backfilling construction stage, and the target foundation pit support removal construction stage are output to obtain the dynamic simulation results of the re-service construction.
[0011] Furthermore, based on the finite element model of the target foundation pit, the activation and failure strategies of the element birth and death method are used to implement dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit. In the process of obtaining the dynamic simulation results of the re-service construction, the activation state of the additional elements that share nodes with the existing support structure elements is changed to simulate the historical deformation and material aging effects of the existing support structure elements.
[0012] This invention also provides a simulation system for the re-service retrofitting of underground foundation pits, comprising: The data acquisition module is used to acquire multidimensional feature data of the target foundation pit; the multidimensional feature data of the target foundation pit includes historical monitoring data, current status data of the foundation pit and real-time monitoring data. The parameter inversion module is used to perform parameter inversion on the soil parameters and damage coefficients of the existing support structure of the target foundation pit by using the two-point ray tracing method and combining the multi-dimensional feature data of the target foundation pit. After regularization processing, the parameter inversion results are obtained. The model building module is used to establish a finite element model of the target foundation pit based on the parameter inversion results, using the finite element method and the element birth and death method. The finite element model of the target foundation pit includes existing support structure elements, soil elements, backfill concrete elements, and additional elements that share nodes with the existing support structure elements. The backfill concrete elements include backfill concrete occupant elements and backfill concrete formal elements. The construction simulation module is used to perform dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit based on the finite element model of the target foundation pit and using the element activation and failure strategy of the birth and death element method to obtain the dynamic simulation results of the re-service construction. The collaborative optimization module is used to combine the dynamic simulation results of re-service construction to carry out collaborative stress optimization design, obtain the optimal demolition rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system.
[0013] The present invention also provides an electronic device, comprising: A processor is used to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, performs the simulation method for the re-service retrofit of underground foundation pits.
[0014] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the simulation method for the re-service retrofit of underground foundation pits.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The simulation method for the re-service retrofitting of underground foundation pits provided by this invention acquires multi-dimensional feature data of the target foundation pit, employs a two-point ray tracing method combined with regularization to perform parameter inversion on soil parameters and damage coefficients of existing support structures, comprehensively and accurately reflecting the actual condition of the foundation pit. Based on the inversion results, a finite element model containing multiple elements is established, and dynamic simulation is implemented using the activation and failure strategy of the birth and death element method, effectively preserving the historical deformation field and material aging effects of the existing support structure, achieving smooth switching of constitutive relations and continuous inheritance of deformation fields at different construction stages. Finally, the optimal demolition rate and buffer layer design parameters are obtained through collaborative stress optimization design, providing a reliable basis for the re-service retrofitting construction of foundation pits. This invention significantly improves the accuracy of simulation results, ensures the safety and controllability of actual construction, and meets the actual needs of engineering projects.
[0016] The simulation system, electronic equipment, computer-readable storage medium, and computer program products for the re-service retrofit of underground foundation pits provided by this invention possess all the advantages of the aforementioned simulation methods for the re-service retrofit of underground foundation pits. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A flowchart of the simulation method for the re-service modification of underground foundation pits provided in Example 1; Figure 2 This is a structural block diagram of the simulation system for the re-service modification of underground foundation pits provided in Example 2; Figure 3 This is a structural block diagram of the electronic device provided in Example 3. Detailed Implementation
[0019] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0020] This invention provides a simulation method for the service remodeling of underground foundation pits, comprising the following steps: Step 100: Obtain multidimensional feature data of the target foundation pit; wherein, the multidimensional feature data of the target foundation pit includes historical monitoring data, current status data of the foundation pit and real-time monitoring data.
[0021] Step 200: Using the two-point ray tracing method, combined with the multidimensional feature data of the target foundation pit, the soil parameters of the target foundation pit and the damage coefficient of the existing support structure are inverted. After regularization processing, the parameter inversion results are obtained.
[0022] Step 300: Based on the parameter inversion results, establish a finite element model of the target foundation pit using the finite element method and the element birth and death method. The finite element model of the target foundation pit includes existing support structure elements, soil elements, backfill concrete elements, and additional elements that share nodes with the existing support structure elements. The backfill concrete elements include backfill concrete occupant elements and backfill concrete formal elements.
[0023] Step 400: Based on the finite element model of the target foundation pit, use the element activation and failure strategy of the birth and death element method to carry out dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit, and obtain the dynamic simulation results of the re-service construction.
[0024] Step 500: Based on the dynamic simulation results of the re-service construction, conduct collaborative stress optimization design to obtain the optimal demolition rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system.
[0025] In the above embodiments, by acquiring historical monitoring data, current status data, and real-time monitoring data of the target foundation pit, and utilizing the fusion of multi-dimensional feature data, the actual condition of the foundation pit at different stages can be more comprehensively reflected. Specifically, due to the time-sensitive nature of geological parameters, incorporating real-time monitoring data of the target foundation pit allows for timely capture of significant changes in soil mechanical properties over time, providing a more accurate and comprehensive basis for subsequent parameter inversion and effectively reducing simulation deviations caused by inaccurate parameters. A two-point ray tracing method is used, combined with multi-dimensional feature data, to perform parameter inversion on the soil parameters of the target foundation pit and the damage coefficient of the existing support structure, and then... Regularization processing integrates soil parameters and the damage state of the existing support structure into the inversion framework, enabling a more comprehensive and accurate reflection of the actual engineering conditions during the foundation pit modification process. This makes the inversion results more reliable and lays a solid foundation for subsequent finite element modeling and simulation analysis, thereby more accurately assessing the structural safety during the foundation pit modification process. When establishing the finite element model of the target foundation pit, based on the finite element method and the element birth and death method, a model is constructed that includes existing support structure elements, soil elements, backfill concrete elements, and additional elements sharing nodes with the existing support structure elements. This fully considers the historical deformation field and material aging effects of the existing support structure. While simulating the excavation and unloading process, the system effectively preserves historical deformation fields and material aging effects, avoiding significant deviations in stress redistribution predictions during the support removal construction phase. This allows for a more accurate understanding of the actual stress state of the existing support structure and a more precise assessment of its losses. In dynamic simulation analysis based on the finite element model, the element activation and failure strategy of the birth and death element method effectively achieves smooth switching of material constitutive relations at different construction stages and continuous inheritance of existing deformation fields. This enables more accurate capture of dynamic changes in the structure during the simulation of foundation pit modification, further improving the accuracy of the simulation and providing better performance. This invention effectively meets the needs of actual engineering projects. By combining the dynamic simulation results of re-service construction and conducting collaborative stress optimization design, it can obtain the optimal removal rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system. This provides a scientific and reasonable design basis for actual engineering projects, helps to improve the safety and controllability of construction, reduce construction risks, and ensure project quality. Through comprehensive and accurate acquisition of parameters, precise simulation of the construction process, and improvement of optimized design schemes, this invention can more accurately capture the dynamic changes of the structure, providing a reliable basis for actual engineering projects, thereby realizing the safe reuse of abandoned foundation pits.
[0026] The following specific embodiments further explain the simulation method for the re-service retrofit of underground foundation pits provided by the present invention: Example 1 As attached Figure 1As shown in the figure, this embodiment 1 provides a simulation method for the in-service modification of underground foundation pits, including the following steps: Step 1: Obtain multidimensional feature data of the target foundation pit. This multidimensional feature data includes historical monitoring data, current status data, and real-time monitoring data. By comprehensively collecting multidimensional feature data encompassing historical monitoring data, current status data, and real-time monitoring data, a rich and comprehensive information foundation is provided for subsequent parameter inversion.
[0027] Specifically, the historical monitoring data of the target foundation pit includes geological exploration data and historical construction records. Geological exploration data includes soil layer distribution, rock mechanical parameters, groundwater level and permeability coefficient, while historical construction records include excavation construction data and existing support structure construction data.
[0028] The current status data of the target foundation pit includes the current geological environment data and the status data of the existing support structure. The current geological environment data includes, for example, the current groundwater level, soil moisture content, and changes in the surrounding environment, such as settlement of adjacent buildings and displacement of pipelines. The status data of the existing support includes, for example, the deformation, cracks, corrosion degree, and integrity of connection nodes of the support piles, anchor cables and supports.
[0029] The real-time monitoring data of the target foundation pit includes real-time dynamic change data of the target foundation pit; among which, the real-time dynamic change data of the target foundation pit includes displacement, stress distribution and strain data of the target foundation pit; more specifically, the displacement of the target foundation pit includes lateral displacement of the support piles, bottom heave and three-dimensional spatial displacement; stress distribution includes active earth pressure, passive earth pressure and stress of the support structure; strain data includes structural cracking strain or axial strain.
[0030] Step 2: Using a two-point ray tracing method, combined with the multidimensional feature data of the target foundation pit, parameter inversion is performed on the soil parameters and damage coefficients of the existing support structure of the target foundation pit. After regularization processing, the parameter inversion results are obtained. The parameter inversion results are inversion vectors containing the soil parameters and damage coefficients of the existing support structure of the target foundation pit. The soil parameters include density, elastic modulus, and Poisson's ratio. The damage coefficients of the support structure reflect the degree of damage to the support structure caused by stress and aging.
[0031] Specifically, the two-point ray tracing method is first used to perform parameter inversion on the soil parameters and damage coefficients of the existing support structure of the target foundation pit by combining the multi-dimensional feature data of the target foundation pit, and then the preliminary parameter inversion results are obtained. It should be noted that the two-point ray tracing method is based on ray theory. By simulating the propagation path of rays in the medium to infer the parameters of the medium, it can more accurately handle the ray propagation problem under complex geological conditions. The soil parameters and the damage coefficients of the support structure are uniformly included in the inversion vector to achieve comprehensive inversion of geological and structural parameters.
[0032] Secondly, the preliminary parameter inversion results are regularized using a predetermined regularization method to obtain the parameter inversion results. It is worth noting that during the parameter inversion process, due to the possibility of noise and incompleteness in the data, the preliminary parameter inversion results obtained directly may be unstable or inaccurate. Therefore, regularization is used to optimize the inversion process by introducing additional constraints, such as smoothing constraints or prior information constraints, so as to make the inversion results more stable and reliable and reduce overfitting.
[0033] It is worth noting that, during the parameter inversion of the soil layer parameters of the target foundation pit using the two-point ray tracing method combined with multidimensional feature data of the target foundation pit, the soil layer parameters of the target foundation pit are inverted based on the changes in soil layer depth and following a layered progressive inversion strategy. Specifically, considering the layered characteristics of the geological structure, the soil layer parameters of the target foundation pit's upper region are first inverted using multidimensional feature data of the preset shallow region, and then the soil layer parameters of the target foundation pit's lower region are inverted using multidimensional feature data of the preset deep region. As the underlying structure is gradually explored, the accuracy of the inversion results is ensured.
[0034] Step 3: Based on the parameter inversion results, establish the finite element model of the target foundation pit using the finite element method and the element birth and death method. The finite element model of the target foundation pit includes existing support structure elements, soil elements, backfill concrete elements, additional elements that share nodes with the existing support structure elements, and transition layer elements between the existing support structure elements and the backfill concrete elements; wherein, the backfill concrete elements include backfill concrete occupant elements and backfill concrete formal elements; the existing support structure is the existing support piles and diaphragm walls in the target foundation pit.
[0035] The existing support structure unit is equipped with an elastoplastic constitutive model that considers the effects of material aging and cumulative damage, used to describe the actual working state of the existing structure. Additional units sharing nodes with the existing support structure unit are used to record and inherit the historical stress and deformation responses at those locations. Through phased activation and failure control of the stacked units, the dynamic changes in material constitutive properties and the evolution of stress states during construction are simulated. The process of establishing additional units sharing nodes with the existing support structure unit is as follows: a set of unit structures sharing nodes with the existing support structure unit is stacked at the corresponding positions of the existing support structure unit to obtain the additional units sharing nodes. The additional units sharing nodes with the existing support structure unit are equipped with a linear elastic constitutive model with a preset elastic modulus, thereby achieving the inheritance of the existing deformation field and smooth switching of constitutive relationships at different construction stages. Specifically, the rule for determining the preset elastic modulus is that it enables the additional unit to be activated when needed and to assume new material properties or structural functions, while its impact on the stiffness and load-bearing capacity of the overall model is negligible during non-working stages, i.e., failure states.
[0036] Soil elements and backfill concrete elements are distributed in the soil excavation area during the re-service reconstruction of the target foundation pit. Soil elements represent the soil structure to be excavated in the soil excavation area, and backfill concrete elements represent the backfill concrete structure in the excavation area. The modeling sequence of soil elements and backfill concrete elements includes: pre-arranging elements representing the backfill concrete structure in the soil excavation area to obtain backfill concrete elements; then, simultaneously setting elements representing the soil structure at the same nodes as the backfill concrete elements to obtain soil elements. Soil elements are assigned a soil Mohr-Coulomb constitutive model, and backfill concrete elements are assigned a concrete damage plastic constitutive model to achieve an essential transformation of material constitutive properties between soil conditions and backfill concrete conditions. Specifically, in step 4, the element activation and failure strategy of the birth and death element method is used to activate or fail soil elements and backfill concrete elements, achieving an essential transformation of material constitutive properties between soil conditions and backfill concrete conditions. This is significantly different from the simple parameter replacement in conventional finite element methods and can significantly improve the realism of simulation results.
[0037] The elastic modulus of the transition layer unit between the existing support structure unit and the backfill concrete unit decreases gradually from the existing support structure side to the backfill concrete side in the target foundation pit according to the preset exponential decay law, effectively reducing the stress concentration at the interface between the existing support structure and the backfill concrete structure.
[0038] Step 4: Based on the finite element model of the target foundation pit, use the element activation and failure strategy of the birth and death element method to carry out dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit, and obtain the dynamic simulation results of the re-service construction.
[0039] Specifically, the process is as follows: Step 41: Initialize the activation state of all elements in the finite element model of the target foundation pit; Step 42: According to the construction progress of the preset excavation area in the target foundation pit, the activation state of the soil unit is set to failure level by level, and the activation state of the backfill concrete occupant unit is set to activation level by level. The simulation results of the target foundation pit excavation construction stage are obtained through simulation. During the simulation, the existing support structure unit and the backfill concrete occupant unit are kept in the calculation simultaneously to reflect the stress and deformation evolution during the continuous excavation of the foundation pit. The simulation results of the target foundation pit excavation construction stage are specifically the deformation field and stress distribution of the target foundation pit excavation construction node obtained through simulation.
[0040] Step 43: According to the construction progress of backfill concrete in the target foundation pit, the activation state of the formal unit of backfill concrete is set to active level by level, and the activation state of the occupant unit of backfill concrete is set to inactive level by level. The constitutive and stiffness replacement from soil condition to backfill concrete condition is completed, and the simulation results of the backfill construction stage of the target foundation pit are obtained through simulation solution. Specifically, the simulation results of the backfill construction stage of the target foundation pit are the deformation field and stress distribution of the excavation construction node of the target foundation pit obtained through simulation solution.
[0041] Step 44: Adopt a graded unloading stress release strategy, gradually reduce the internal forces of the existing support structure unit according to the preset time history, so that the lateral load on the existing support structure unit is transferred to the backfill concrete formal unit and the newly built external wall structure system, and obtain the simulation results of the target foundation pit support removal construction stage through simulation solution; wherein, the simulation results of the target foundation pit backfill construction stage are specifically the deformation field and stress distribution of the target foundation pit excavation construction node obtained through simulation solution.
[0042] Step 45: Output the simulation results of the target foundation pit excavation construction stage, the target foundation pit backfilling construction stage, and the target foundation pit support removal construction stage to obtain the dynamic simulation results of the re-service construction.
[0043] It is worth noting that by superimposing additional units that share nodes with the existing support structure units at the location of the existing support structure units and assigning them differentiated material properties, the accurate inheritance of the existing deformation of the existing support structure and the essential transformation of the material constitutive relationship are achieved, completely solving the problem of discontinuous stress transfer path in the backfilling stage in traditional methods. Through the construction simulation process, the phased activation and failure control of soil units, superimposed backfill concrete occupant units and backfill concrete formal units form a dynamic transformation mechanism of material constitutive structure, realizing the essential transformation between soil and concrete constitutive models, rather than simple parameter replacement, which greatly improves the accuracy of stress analysis at the contact surface.
[0044] Step 5: Based on the dynamic simulation results of the re-service construction, a collaborative stress optimization design is performed to obtain the optimal removal rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system. Specifically, based on the dynamic simulation results of the re-service construction, a support force release model that explicitly considers the time effect is constructed. Through parameter sensitivity analysis, the optimal removal rate of the existing support structure of the target foundation pit is obtained. Secondly, based on the dynamic simulation results of the re-service construction, through parameter inversion, the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system are obtained. Among them, the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system are specifically the elastic modulus of the buffer layer, which significantly improves the stress transmission path, enhances the overall safety and durability during the re-service transformation of the foundation pit, ensures a smooth transition of force flow during the transformation of the abandoned foundation pit, and provides a systematic solution for the long-term collaborative work of backfill concrete and support structure. Optionally, the thickness of the buffer layer can be set variably.
[0045] The simulation method for the re-service retrofit of underground foundation pits shown in Example 1 acquires multi-dimensional feature data of the target foundation pit, performs parameter inversion on the soil parameters and damage coefficients of the existing support structure, establishes a finite element model of the target foundation pit based on the parameter inversion structure, implements dynamic simulation analysis of the re-service retrofit construction based on the finite element model of the target foundation pit, and performs collaborative stress optimization design based on the dynamic simulation results of the re-service construction. This realizes the simulation of the safe reuse process of abandoned foundation pits, ensuring the safety and controllability of actual construction.
[0046] In this embodiment 1, a multi-dimensional data acquisition strategy is constructed by integrating historical monitoring data, current status data, and real-time monitoring data of the target foundation pit to obtain multi-dimensional feature data of the target foundation pit. Based on the multi-dimensional feature data of the target foundation pit, a two-point ray tracing algorithm is used for parameter inversion, and soil parameters and support structure damage coefficients are uniformly incorporated into the inversion vector. Regularization processing is used to ensure the stability of the inversion results. Secondly, during the parameter inversion process, a layered progressive inversion strategy is established. First, the upper parameters are inverted using shallow data, and then the lower parameters are inverted using deep data. A parameter transition zone is set for the layered contact area to avoid abrupt changes in stiffness.
[0047] In this embodiment 1, a finite element model of the target foundation pit is established based on the modeling strategy of finite element method and element birth and death method, combined with the parameter inversion results. Among them, for the existing support structure unit, a set of additional units sharing nodes with the original unit are superimposed at the corresponding position. The existing support structure unit is given an elastoplastic constitutive model that can reflect the material aging and cumulative damage effect to describe the actual working state of the existing support structure unit. The additional units adopt a linear elastic constitutive model with a preset elastic modulus, so that the additional units can be activated when needed to take on new material properties or structural functions, while the influence on the overall stiffness and stress in the non-working stage can be ignored, thereby realizing the inheritance of the existing deformation field and the smooth switching of constitutive relations in different construction stages.
[0048] In addition, elements representing the backfill concrete structure are pre-arranged in the soil excavation area to obtain backfill concrete elements; elements representing the soil are simultaneously set at the same nodes as the backfill concrete elements to obtain soil elements; the backfill concrete elements and soil elements are respectively assigned concrete damage plastic constitutive models and soil Mohr-Coulomb constitutive models. Through subsequent element activation and failure control, the essential transformation of material constitutive properties between soil conditions and backfill concrete conditions is achieved rather than simple parameter replacement; in terms of contact surface treatment, in the contact area between the existing support structure and the backfill concrete structure, transition layer elements of a preset thickness are set along the thickness direction. The elastic modulus of the transition layer elements decreases stepwise from the support side to the backfill side according to a preset exponential decay law, effectively reducing the stress concentration near the interface.
[0049] In this embodiment 1, the dynamic simulation of the construction process includes three stages: excavation, backfilling, and support removal transition. By activating and controlling the failure of soil units, backfill concrete units, and additional units, the essential transformation between the constitutive properties of different materials and the continuous transition of stress states are achieved. Specifically, in the excavation stage, the soil units within the excavation range are set to a failure state, while the backfill concrete occupant units sharing the same nodes are activated. The existing support structure units and the backfill concrete occupant units participate in the calculation synchronously to reflect the stress and deformation evolution during the continuous excavation of the foundation pit. In the backfilling stage, the backfill concrete formal units are activated, and the backfill concrete occupant units at the corresponding positions are set to a failure state, thereby completing the constitutive and stiffness replacement from the soil condition to the backfill concrete condition. In the support removal transition stage, a graded unloading stress release strategy is introduced to gradually reduce the internal forces of the support components according to a pre-set time history, so that the load on the lateral support structure of the foundation pit is smoothly transferred to the backfill concrete and the newly built external wall structure system.
[0050] In this embodiment 1, the backfill concrete co-stressing technology based on the element birth and death method solves the problem of discontinuous stress transmission path in traditional backfilling processes by superimposing additional element systems with shared nodes with the original elements at the location of the existing support structure and assigning differentiated material properties. This achieves accurate inheritance of the existing deformation of the support structure and essential transformation of the material constitutive relationship. Through the phased activation and failure control of the superimposed soil elements and backfill concrete elements during construction, a dynamic transformation mechanism of material constitutive is formed, realizing the essential transformation between the soil and concrete constitutive models, rather than simple parameter replacement, which greatly improves the accuracy of stress analysis at the contact surface. When combining the dynamic simulation results of re-service construction for co-stressing optimization design, by establishing a time-varying dismantling force model and a buffer layer modulus gradient change formula, the smooth transition of force flow during the transformation of abandoned foundation pits is ensured, providing a systematic solution for the long-term co-working of backfill concrete and support structure.
[0051] Example 2 As attached Figure 2 As shown, based on the same inventive concept as Embodiment 1 above, Embodiment 2 provides a simulation system for the re-service retrofit of underground foundation pits, including a data acquisition module, a parameter inversion module, a model building module, a construction simulation module, and a collaborative optimization module.
[0052] The data acquisition module is used to acquire multidimensional feature data of the target foundation pit, including historical monitoring data, current status data, and real-time monitoring data. The parameter inversion module uses a two-point ray tracing method, combined with the multidimensional feature data, to perform parameter inversion on the soil parameters and damage coefficients of the existing support structure of the target foundation pit, and obtains the parameter inversion results after regularization. The model construction module, based on the parameter inversion results, establishes a finite element model of the target foundation pit using the finite element method and the element birth and death method. The finite element model of the target foundation pit includes existing support structure elements, soil elements, and backfill elements. The system includes concrete units and additional units that share nodes with existing support structure units; backfill concrete units include backfill concrete occupant units and backfill concrete formal units; a construction simulation module is used to perform dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit based on the finite element model of the target foundation pit and using the element activation and failure strategy of the birth and death element method to obtain the dynamic simulation results of the re-service construction; and a collaborative optimization module is used to combine the dynamic simulation results of the re-service construction to perform collaborative stress optimization design, obtain the optimal demolition rate of the existing support structure of the target foundation pit and the design parameters of the buffer layer between the existing support structure and the newly built external wall structure system.
[0053] Example 3 As attached Figure 3 As shown, this embodiment 3 provides an electronic device, including: a memory for storing a computer program; a processor for executing the computer program to implement the steps of a simulation method for the re-service retrofit of underground foundation pits; or, the processor for executing the computer program to implement the functions of each module in the above-mentioned simulation system for the re-service retrofit of underground foundation pits.
[0054] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a preset function, the instruction segments describing the execution process of the computer program in the electronic device.
[0055] The electronic device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above are examples of electronic devices and do not constitute a limitation on the electronic device. It may include more components than described above, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.
[0056] The processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor, or any conventional processor, etc. The processor is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines.
[0057] The memory can be used to store the computer program and / or module. The processor implements various functions of the electronic device by running or executing the computer program and / or module stored in the memory and by calling the data stored in the memory.
[0058] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function (such as sound playback, image playback, etc.). The data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart memory cards, secure digital cards, flash memory cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.
[0059] Example 4 This embodiment 4 also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the simulation method for the re-service retrofit of underground foundation pits.
[0060] If the modules / units of the simulation system integrated for the re-service retrofit of underground foundation pits are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.
[0061] Based on this understanding, the present invention can implement all or part of the processes in the simulation method for the re-service retrofit of underground foundation pits, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the simulation method for the re-service retrofit of underground foundation pits. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or a preset intermediate form, etc.
[0062] The computer-readable storage medium may include any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal, and software distribution medium, etc.
[0063] The simulation method for the re-service renovation of underground foundation pits described in this invention is specifically designed for existing foundation pit renovation projects with aging support structures and unclear geological conditions. It involves acquiring multi-dimensional characteristic data of the target foundation pit, performing parameter inversion on the soil parameters and damage coefficients of the existing support structure, establishing a finite element model of the target foundation pit based on the parameter inversion structure, conducting dynamic simulation analysis of the re-service renovation construction based on the finite element model, and performing collaborative stress optimization design by combining the dynamic simulation results of the re-service construction. This method solves the problems of poor timeliness of geological parameters, difficulty in quantifying existing deformations of the support structure, and unclear force flow transmission paths between the old and new structures encountered by traditional methods in the reuse of abandoned foundation pits. It is applicable to the numerous existing foundation pit renovation projects in urban renewal, and can significantly improve structural safety and economy.
[0064] In this invention, by acquiring multidimensional feature data of the target foundation pit, a two-point ray tracing method combined with regularization is used to perform parameter inversion on soil layer parameters and existing support structure damage coefficients, which can comprehensively and accurately reflect the actual condition of the foundation pit. The two-point ray tracing algorithm is used for parameter inversion, and soil layer parameters and support structure damage coefficients are uniformly included in the inversion vector. Regularization is used to ensure the stability of the inversion results. Among them, a layered progressive inversion strategy is established, first inverting the upper parameters using shallow data, and then using deep data to invert the lower parameters. A parameter transition zone is set for the contact surface area to avoid abrupt changes in stiffness.
[0065] In this invention, a modeling strategy based on the element birth and death method is adopted. A set of additional elements sharing nodes with the original elements are superimposed at the corresponding positions of the existing support structure elements. The existing support structure elements are given an elastoplastic constitutive model that can reflect the effects of material aging and cumulative damage to describe the actual working state of the existing structure. The additional elements adopt a linear elastic constitutive model with extremely low elastic modulus, so that the additional elements can be activated when needed to assume new material properties or structural functions, while the influence on the overall stiffness and stress during non-working stages can be ignored, thereby realizing the inheritance of the existing deformation field and the smooth switching of constitutive relationships at different construction stages. Elements representing backfill concrete are pre-arranged in the soil excavation area, and corresponding soil elements are simultaneously set at the same nodes, respectively given a concrete damage plastic constitutive model and a soil Mohr-Coulomb constitutive model, to realize the essential transformation of material constitutives between soil working conditions and backfill concrete working conditions.
[0066] In this invention, during the excavation stage, the original soil units within the excavation area are set to a failed state, while the backfill concrete occupant units sharing the same nodes are activated. The existing support structure units and the backfill concrete occupant units participate in the calculation synchronously to reflect the stress and deformation evolution during continuous excavation. During the backfilling stage, the formal units representing the backfill concrete are activated, and the corresponding backfill concrete occupant units are gradually set to a failed state, thus completing the constitutive and stiffness transition from the soil condition to the backfill concrete condition. During the dismantling and transition stage, a progressive stress release strategy is adopted, gradually reducing the internal forces of the support components according to a pre-set time history, smoothly transferring the lateral loads on the support structure to the backfill concrete and newly constructed external wall structure system. Furthermore, in terms of collaborative stress optimization design, a support force release model explicitly considering time effects is established. The optimal dismantling rate is determined through parameter sensitivity analysis, and a variable-thickness buffer layer is set between the support piles and the newly constructed external wall. Its elastic modulus is determined through inversion, significantly improving the stress transmission path and enhancing the overall safety and durability during the re-service modification process of the foundation pit.
[0067] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.
Claims
1. A simulation method for the re-service reconstruction of an underground foundation pit, characterized in that, The method comprises the following steps: acquiring multi-dimensional characteristic data of a target foundation pit; wherein the multi-dimensional characteristic data of the target foundation pit comprises historical monitoring data, current data and real-time monitoring data of the target foundation pit; adopting a two-point ray tracing method, combining the multi-dimensional characteristic data of the target foundation pit, performing parameter inversion on soil layer parameters and damage coefficients of an existing supporting structure of the target foundation pit, and after regularization processing, obtaining a parameter inversion result; based on the parameter inversion result, establishing a finite element model of the target foundation pit based on a finite element method and an element birth and death method; wherein the finite element model of the target foundation pit comprises an existing supporting structure element, a soil element, a backfill concrete element and an additional element sharing nodes with the existing supporting structure element; the backfill concrete element comprises a backfill concrete placeholder element and a backfill concrete formal element; based on the finite element model of the target foundation pit, using the element activation and failure strategy of the element birth and death method, performing dynamic simulation analysis of the target foundation pit for the re-service reconstruction construction, and obtaining a dynamic simulation result of the re-service construction; combining the dynamic simulation result of the re-service construction, performing collaborative stress optimization design, and obtaining an optimal removal rate of the existing supporting structure of the target foundation pit and design parameters of a buffer layer between the existing supporting structure and a newly-built outer wall structure system.
2. The simulation method for the re-service reconstruction of the underground foundation pit according to claim 1, characterized in that, The historical monitoring data of the target foundation pit comprises geological exploration data and historical construction record information of the target foundation pit; the current data of the target foundation pit comprises current geological environment data and state data of the existing supporting structure of the target foundation pit; the real-time monitoring data of the target foundation pit comprises real-time dynamic change data of the target foundation pit; wherein the real-time dynamic change data of the target foundation pit comprises displacement, stress distribution and strain data of the target foundation pit.
3. The simulation method for the re-service reconstruction of the underground foundation pit according to claim 1, characterized in that, In the process of performing parameter inversion on the soil layer parameters of the target foundation pit by adopting the two-point ray tracing method and combining the multi-dimensional characteristic data of the target foundation pit, based on the depth change of the soil layer of the target foundation pit, the parameter inversion on the soil layer parameters of the target foundation pit is performed according to a layered progressive inversion strategy.
4. The simulation method for the re-service reconstruction of the underground foundation pit according to claim 1, characterized in that, The existing supporting structure element is endowed with an elastic-plastic constitutive model considering material aging and cumulative damage effect; the soil element is endowed with a soil Mohr-Coulomb constitutive model; the backfill concrete element is endowed with a concrete damage plastic constitutive model; and the additional element sharing nodes with the existing supporting structure element is endowed with a linear elastic constitutive model with a preset elastic modulus.
5. The simulation method for re-service reconstruction of an underground foundation pit according to claim 1, characterized in that, The finite element model of the target foundation pit further comprises a transition layer element between the existing supporting structure element and the backfill concrete element; wherein the elastic modulus of the transition layer element between the existing supporting structure element and the backfill concrete element gradually decays from the side of the existing supporting structure of the target foundation pit to the side of the backfill concrete after reconstruction according to a preset exponential decay law.
6. The simulation method for re-service reconstruction of an underground foundation pit according to claim 1, characterized in that, The process of performing dynamic simulation analysis of the target foundation pit for the re-service reconstruction construction based on the finite element model of the target foundation pit and using the element activation and failure strategy of the element birth and death method to obtain the dynamic simulation result of the re-service construction comprises the following steps: initializing the activation state of all elements in the finite element model of the target foundation pit; According to the construction progress of the preset excavation area in the target foundation pit, the activation state of the soil unit is gradually set to be invalid, and the activation state of the backfill concrete occupying unit is gradually set to be activated, and simulation solving is performed, to obtain the simulation simulation result of the target foundation pit excavation construction stage; According to the construction progress of the backfill concrete in the target foundation pit, the activation state of the backfill concrete formal unit is gradually set to be activated, and the activation state of the backfill concrete occupying unit is gradually set to be invalid, and simulation solving is performed, to obtain the simulation simulation result of the target foundation pit backfill construction stage; A stress release strategy of hierarchical unloading is adopted, the internal force of the existing supporting structure unit is gradually reduced according to the preset time history, the lateral load on the existing supporting structure unit is transferred to the backfill concrete formal unit, and simulation solving is performed, to obtain the simulation simulation result of the target foundation pit support removal construction stage; The simulation simulation result of the target foundation pit excavation construction stage, the simulation simulation result of the target foundation pit backfill construction stage and the simulation simulation result of the target foundation pit support removal construction stage are output, to obtain the dynamic simulation simulation result of the re-service construction.
7. The simulation method for the re-service reconstruction of the underground foundation pit according to claim 6, characterized in that, In the process of implementing the dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit based on the finite element model of the target foundation pit and using the element activation and invalidation strategy of the birth-death element method, the activation state of the additional element sharing the node with the existing supporting structure unit is changed to simulate the historical deformation and material aging effect of the existing supporting structure unit.
8. A simulation system for the re-service modification of underground foundations, characterized in that, It comprises: A data acquisition module is configured to acquire multi-dimensional feature data of a target foundation pit; wherein the multi-dimensional feature data of the target foundation pit comprises historical monitoring data, current status data and real-time monitoring data of the target foundation pit; A parameter inversion module is configured to use a two-point ray tracing method to perform parameter inversion on soil layer parameters and damage coefficients of an existing supporting structure of the target foundation pit in combination with the multi-dimensional feature data of the target foundation pit, and obtain a parameter inversion result after regularization processing; A model construction module is configured to establish a finite element model of the target foundation pit based on the finite element method and the element birth-death method according to the parameter inversion result; wherein the finite element model of the target foundation pit comprises existing supporting structure units, soil units, backfill concrete units and additional units sharing nodes with the existing supporting structure units; the backfill concrete units comprise backfill concrete occupying units and backfill concrete formal units; A construction simulation simulation module is configured to implement dynamic simulation analysis of the re-service reconstruction construction of the target foundation pit based on the finite element model of the target foundation pit and using the element activation and invalidation strategy of the birth-death element method, to obtain a dynamic simulation simulation result of the re-service construction; A collaborative optimization module is configured to perform collaborative stress optimization design in combination with the dynamic simulation simulation result of the re-service construction, to obtain an optimal removal rate of the existing supporting structure of the target foundation pit and design parameters of a buffer layer between the existing supporting structure and a newly-built outer wall structure system.
9. An electronic device, comprising: It comprises: A processor is adapted to execute a computer program. A computer readable storage medium, in which a computer program is stored, which, when executed by a processor, performs the simulation method for the re-service reconstruction of an underground foundation pit according to any one of claims 1-7.
10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 9. The computer program is executed by a processor to implement the simulation method for the re-service reconstruction of an underground foundation pit according to any one of claims 1-7.