Underground structure hybrid test system considering stratum loss and control method

Abstract

The application belongs to the technical field of underground structure test, and provides an underground structure hybrid test system and control method considering stratum loss, which comprises: a numerical substructure for determining boundary node displacement on an interactive boundary corresponding to a current analysis step; a virtual test substructure for calculating boundary node force according to the boundary node displacement and current gravity, and obtaining node force simulation value in combination with a similarity coefficient, and further determining concentrated force for loading; a test substructure for obtaining loading force and displacement data through the concentrated force; and a parameter inversion module for inverting the loading force and displacement data to obtain material parameters under current boundary conditions, so as to update the numerical model of the test substructure and the boundary node force, and further determine a target unbalanced force, so that the interactive boundaries among the structures satisfy displacement coordination and force balance. The system realizes fine simulation of multi-field coupling mechanism under complex geological conditions, and improves stratum loss simulation accuracy.

Description

Technical Field

[0001] This invention relates to the field of underground structure testing technology, and in particular to a hybrid testing system and control method for underground structures that takes into account ground loss. Background Technology

[0002] With the increasingly intensive development and utilization of urban underground space, the safety and stability of underground structures have received growing attention. For example, the presence of soil arches can significantly reduce the vertical load on a structure and improve its structural safety margin. During the long-term service of existing underground structures, the soil arches surrounding them may be damaged by external factors such as nearby disturbances or strong earthquakes. Once the soil arches become unstable, the external loads on the structure will increase significantly, leading to sudden changes in internal forces and even structural failure. Therefore, how to realistically and reasonably reproduce the stress state and soil arch effect of the strata surrounding the existing structure during the construction phase in physical model tests is key to improving test accuracy and engineering reliability.

[0003] Among related technologies, the main methods for simulating formation loss include the drainage method, the dewatering method, the mechanical convergence method, and the tube-pulling method. Since actual formation loss is a gradual process, the drainage method, which simulates volume loss by instantaneous depressurization or drainage, is difficult to reproduce the time-related soil creep effect. The dewatering method only simulates volume loss by drainage, and the simulation results deviate significantly from reality. The mechanical convergence method simulates formation loss by forced contraction, which may change the original stress state of the soil (such as insufficient lateral stress release), leading to distortion of the stress-strain relationship. The tube-pulling method is only suitable for simulating sandy soil or loose formations and is difficult to accurately reproduce the gradual failure process (such as crack propagation) of cohesive soil or cemented formations. The above-mentioned formation loss simulation methods have poor simulation effects under complex geological conditions, resulting in inaccurate formation loss simulation results and making it difficult to solve the problem of refined simulation of multi-field coupling mechanisms under complex geological conditions. Summary of the Invention

[0004] This invention provides a hybrid test system and control method for underground structures that considers formation loss, in order to solve the defects of existing formation loss simulation methods that have poor simulation effect under complex geological conditions, resulting in inaccurate formation loss simulation results. The hybrid test system for underground structures that considers formation loss described in this invention realizes refined simulation of multi-field coupling mechanisms under complex geological conditions, thereby improving the accuracy of formation loss simulation.

[0005] This invention provides a hybrid testing system for underground structures that considers formation loss, comprising:

[0006] Numerical substructure is used to determine the boundary node displacement of the interactive boundary based on the self-weight load increment corresponding to the current analysis step in multiple analysis steps during the formation gravity loading process.

[0007] The virtual test substructure is used to calculate the boundary node force based on the boundary node displacement and the current gravity, obtain the simulated value of the node force based on the boundary node force and the similarity coefficient, and determine the concentrated force of each loading plate based on the simulated value of the node force and the loading parameters of the loading plate.

[0008] The test substructure is used to apply the concentrated force to the stratum-tunnel model through the actuator, obtain the actuator loading force and the corresponding displacement data, and use the actuator loading force and the corresponding displacement data as the current boundary conditions;

[0009] The virtual test substructure includes a parameter inversion module, which is used to perform parameter inversion on the actuator loading force and corresponding displacement data to obtain the target material parameters of the test substructure under the current boundary conditions.

[0010] The virtual test substructure is also used to update the numerical model of the test substructure according to the target material parameters, and update the boundary nodal forces corresponding to the current boundary conditions; and send the updated boundary nodal forces to the numerical substructure.

[0011] The numerical substructure is also used to determine the target unbalance force based on the updated boundary node force and the boundary node force corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual test substructure and the test substructure satisfies displacement coordination and force balance.

[0012] According to the present invention, a hybrid test system for underground structures considering formation loss is provided, the system further comprising:

[0013] An interactive platform is provided, wherein the numerical substructure and the virtual experimental substructure are respectively connected to the interactive platform; the interactive platform is used for target data interaction between the numerical substructure and the virtual experimental substructure, wherein the target data includes boundary node forces, feedback forces, boundary node displacements, and feedback displacements.

[0014] According to the present invention, a hybrid test system for underground structures considering formation loss is provided, wherein the interactive platform includes OpenFresco and LabVIEW.

[0015] According to the present invention, a hybrid test system for underground structures considering formation loss is provided, wherein different formation properties of the numerical substructure correspond to different compaction parameters;

[0016] The soil in the numerical substructure was simulated using four-node Quad elements in OpenSees, and the soil constitutive model was PDMY.

[0017] According to the present invention, a hybrid test system for underground structures considering ground loss is provided, wherein the test substructure includes a reaction frame, a loading system, and a model box;

[0018] The loading system includes multiple actuator systems and a control system. Each actuator system can extend and retract independently, and the control system is used to control the motion state of the multiple actuator systems.

[0019] According to the present invention, a hybrid test system for underground structures considering formation loss is provided, wherein the test substructure includes:

[0020] The softening layer is made of a material that has the following characteristics: plasticity, target yield strength, zero Poisson's ratio, and processability.

[0021] According to the present invention, a hybrid test system for underground structures considering formation loss is provided, wherein the test substructure further includes:

[0022] A soil-structure scaled-down model, which includes model soil and a model box;

[0023] The model soil is made of standard sand, and a rubber membrane is attached between the model soil and the side wall of the model box. The outer surface of the rubber membrane is covered with PTFE film and petroleum jelly.

[0024] This invention also provides a control method for a hybrid test system for underground structures considering formation loss, comprising:

[0025] Based on the numerical substructure, in multiple analysis steps of the formation gravity loading process, the boundary node displacement of the interactive boundary is determined according to the self-weight load increment corresponding to the current analysis step.

[0026] Based on the virtual test substructure, the boundary node forces are calculated according to the boundary node displacements and the current gravity. The simulated values ​​of the node forces are obtained according to the boundary node forces and the similarity coefficients. The concentrated forces of each loading plate are determined according to the simulated values ​​of the node forces and the loading parameters of the loading plates.

[0027] Based on the experimental substructure, the concentrated force is applied to the stratum-tunnel model through the actuator, the actuator loading force and the corresponding displacement data are obtained, and the actuator loading force and the corresponding displacement data are used as the current boundary conditions.

[0028] Based on the parameter inversion module, the loading force and corresponding displacement data of the actuator are inverted to obtain the target material parameters of the test substructure under the current boundary conditions.

[0029] Based on the virtual test substructure, the numerical model of the test substructure is updated according to the target material parameters, and the boundary nodal forces corresponding to the current boundary conditions are updated; the updated boundary nodal forces are sent to the numerical substructure.

[0030] Based on the numerical substructure, the target unbalance force is determined according to the updated boundary node force and the boundary node force corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual test substructure and the test substructure satisfies displacement coordination and force balance.

[0031] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a control method for a hybrid underground structure test system considering ground loss as described above.

[0032] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a control method for a hybrid underground structure test system considering ground loss as described above.

[0033] The present invention provides a hybrid test system and control method for underground structures considering formation loss. This system determines the boundary node displacements of the interactive boundary based on the self-weight load increment corresponding to the current analysis step using a numerical substructure. Based on the virtual test substructure, it calculates the boundary node forces based on the boundary node displacements and the current gravity, and performs nodal force simulation. Based on the simulated nodal force values ​​and the loading parameters of the loading plates, it determines the concentrated forces of each loading plate to obtain the actuator loading forces. Using the loading forces and corresponding displacement data as the current boundary conditions, it performs parameter inversion on the actuator loading forces and corresponding displacement data to obtain the target material parameters. This updates the numerical model of the test substructure and the corresponding boundary node forces under the current boundary conditions. Based on the numerical substructure, it determines the target unbalanced force based on the updated boundary node forces and the boundary node forces corresponding to the previous analysis step, driving the next analysis step until the interactive boundary between the numerical substructure, the virtual test substructure, and the test substructure satisfies displacement coordination and force balance. This system achieves refined simulation of multi-field coupling mechanisms under complex geological conditions, improving the accuracy of formation loss simulation. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the underground structure hybrid test system considering formation loss provided by the present invention.

[0036] Figure 2 This is a flowchart illustrating the control method of the underground structure hybrid test system considering formation loss provided by the present invention.

[0037] Figure 3 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0038] Figure label:

[0039] 110: Numerical substructure; 120: Virtual experiment substructure; 121: Parameter inversion module;

[0040] 130: Experimental substructure; 140: Interactive platform. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] The following is combined with Figures 1-2 The present invention describes a hybrid test system and control method for underground structures that takes into account formation loss.

[0043] Figure 1 This is a schematic diagram of the underground structure hybrid test system considering formation loss provided by the present invention, as shown below. Figure 1 As shown, it includes: a numerical substructure 110, a virtual experimental substructure 120, and an experimental substructure 130; the virtual experimental substructure 120 includes a parameter inversion module 121.

[0044] Numerical substructure 110 is used to determine the boundary node displacement of the interactive boundary based on the self-weight load increment corresponding to the current analysis step in multiple analysis steps during the formation gravity loading process.

[0045] In this embodiment, the interaction boundary is the common boundary between the OpenFresco test cell that replaces the test substructure portion in the numerical substructure and the soil.

[0046] In this embodiment, there is a data channel for numerical to physical direction transmission at the interaction boundary. For example, the interaction plane can transmit the boundary point displacement calculated by the numerical substructure 110, i.e., the boundary node displacement.

[0047] In this embodiment, the numerical substructure 110 is a computational model constructed by numerical simulation software to simulate large-scale stratigraphic mechanical behavior. The numerical substructure 110 does not include the area where the experimental substructure 130 is located and is used to exchange data with the experimental substructure 130 at the interaction boundary.

[0048] In this embodiment, the numerical substructure 110 is also used to calculate the stress state of the formation in different analysis steps: the numerical substructure 110 calculates the stress distribution of the formation according to the self-weight load increment corresponding to the current analysis step, and based on the calculated stress distribution, the numerical substructure 110 can determine the displacement of each node on the interactive boundary connected to the test substructure 130.

[0049] Specifically, by applying the self-weight load of the current analysis step to the numerical substructure 110 and starting the calculation iteration based on the convergence result of the previous analysis step, in each iteration, the numerical substructure 110 transmits the calculated boundary node displacements to the virtual test substructure 120 or test substructure 130 of the underground structure hybrid test system considering ground loss through the interactive platform 140.

[0050] It should be noted that the underground structure hybrid test considering ground loss in this embodiment includes an initial ground gravity loading stage and a loading stage for disturbances such as adjacent construction or earthquakes during the operation period of the existing underground structure.

[0051] This embodiment can divide the initial formation gravity load loading process into equal parts. n Each analysis step (e.g., n (Take 100); at the same time, in order to avoid distortion in the simulation of formation loss, the softening layer needs to be progressively compressed.

[0052] The virtual test substructure 120 includes a parameter inversion module 121, which is used to perform parameter inversion on the actuator loading force and corresponding displacement data to obtain the target material parameters of the test substructure 130 under the current boundary conditions.

[0053] In this embodiment, the virtual experimental substructure 120 consists of a numerical model and a parameter inversion module 121, which is used to simulate the behavior of the experimental substructure 130 and perform necessary transformations and calculations to achieve synergy between numerical simulation and physical experiment.

[0054] In this embodiment, the virtual test substructure 120 can receive the boundary node displacement transmitted by the numerical substructure 110, calculate the corresponding boundary node force according to its own numerical model, and perform numerical simulation of the boundary node force, converting it into a concentrated force acting on the loading plate.

[0055] In this embodiment, the virtual test substructure 120 can update the numerical model of the test substructure 130 and recalculate the boundary node forces under the current boundary conditions.

[0056] Specifically, the virtual test substructure 120 calculates the response based on the received boundary node displacement and the current self-weight (the response is: soil compression caused by self-weight load → affecting the calculation of boundary node forces), outputs the nodal forces, and then transmits them back to the numerical subsystem via the interactive platform 140.

[0057] The experimental substructure 130 is used to apply concentrated force to the stratum-tunnel model through the actuator, obtain the actuator loading force and corresponding displacement data, and use the actuator loading force and corresponding displacement data as the current boundary conditions.

[0058] In this embodiment, the test substructure 130 is an actual physical model, which includes soil layers, tunnel structure, and loading device, etc.

[0059] In this embodiment, the test substructure 130 includes the following functions:

[0060] (1) Bearing concentrated force loading: The test substructure 130 bears the concentrated force loading transmitted by the virtual test substructure 120 through the actuator.

[0061] (2) Obtaining the actuator loading force and corresponding displacement data: During the loading process, the test substructure 130 will monitor the actuator loading force and corresponding displacement data in real time and feed these data back to the virtual test substructure 120.

[0062] In this embodiment, the test substructure 130 loads the stratum-tunnel model system through an actuator. After the nodal forces are loaded, the material parameters of the stratum-tunnel model system under the current boundary conditions are inverted based on the actuator loading force and the corresponding displacement.

[0063] The parameter inversion module 121 is used to receive the actuator loading force and corresponding displacement data sent by the virtual test substructure 120, perform parameter inversion, and obtain the target material parameters of the test substructure 130 under the current boundary conditions.

[0064] In this embodiment, the parameter inversion module 121 is used to correct the numerical model of the test substructure 130. Specifically, it analyzes the test data of the test substructure 130 to invert the material parameters of the soil layer and structure in the test substructure 130, thereby improving the accuracy of the numerical model.

[0065] The specific functions of the parameter inversion module 121 include:

[0066] (1) Receive actuator loading force and displacement data: The parameter inversion module 121 receives the actuator loading force and corresponding displacement data of the virtual test substructure 120.

[0067] (2) Parameter inversion: The parameter inversion module 121 takes the actuator loading force and the corresponding displacement data as the optimization target, uses the numerical model of the test substructure 130 as the calculation kernel, and uses optimization algorithms (such as genetic algorithm, particle swarm algorithm, etc.) to invert the material parameters of the soil layer and structure.

[0068] (3) Obtain target material parameters: The parameter inversion module 121 outputs the target material parameters of the soil-structure model system in the test substructure 130 under the current boundary conditions.

[0069] In this embodiment, the material parameters of the stratum-tunnel model under the current boundary conditions include soil parameters and softening layer parameters; the stratum-tunnel model is the physical entity of the test substructure 130 (including the stratum part, the tunnel part, and the softening layer), specifically a physical simulation device constructed at a strict scale to reproduce the mechanical effects of stratum loss on the tunnel structure under controlled conditions.

[0070] Among them, soil parameters include elastic modulus, Poisson's ratio, friction angle or plastic hardening coefficient, etc.; softening layer parameters include yield stress, compression modulus or Poisson's ratio, etc.

[0071] The virtual test substructure 120 is also used to update the numerical model of the test substructure 130 according to the target material parameters, and update the corresponding boundary nodal forces under the current boundary conditions; and send the updated boundary nodal forces to the numerical substructure 110.

[0072] In this embodiment, after updating the virtual test substructure 120 by using physical parameters (i.e. target material parameters) that reflect the nonlinear response of the test substructure 130, the boundary force of the virtual test substructure 120 under the boundary displacement is recalculated and fed back to the numerical substructure 110, thereby achieving smooth interaction.

[0073] In this embodiment, since the nodal forces on the interaction boundary of the experimental substructure 130 are the same as those on the numerical substructure 110, they cannot interact. In order for the interaction to proceed smoothly, the interaction boundary nodal forces containing the nonlinear response of the experimental substructure 130 need to be returned to the numerical substructure 110.

[0074] In this embodiment, the numerical model of the virtual test substructure 120 is corrected, which can more accurately simulate the real behavior of the test substructure 130. The updated boundary node forces also more realistically reflect the constraint effect of the test substructure 130 on the surrounding strata, providing more accurate boundary conditions for the subsequent calculation of the numerical substructure 110.

[0075] The numerical substructure 110 is also used to determine the target unbalance force based on the updated boundary node force and the boundary node force corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure 110, the virtual test substructure 120 and the test substructure 130 satisfies displacement compatibility and force balance.

[0076] Specifically, after receiving the updated boundary node forces from the virtual test substructure 120, the numerical substructure 110 needs to calculate the target unbalanced force based on the difference between the node force and the node force corresponding to the previous analysis step. This unbalanced force will be used as the driving force to drive the numerical substructure 110 to perform the next calculation until the entire hybrid test system reaches a state of displacement coordination and force balance, which can achieve the coordinated convergence of numerical simulation and physical experiment, and ensure the accuracy and reliability of the hybrid test results.

[0077] In this embodiment, the process of driving the analysis step through unbalanced force includes: taking the sum of the unbalanced force calculated in the k-th analysis step and the initial self-weight load corresponding to the (k+1)-th analysis step as the self-weight load input for the (k+1)-th analysis step, thus realizing the technical chain of force difference at the current analysis step node → calculation of unbalanced force → correction of self-weight load for the next analysis step, which can solve the problem of "physical nonlinearity cannot be fed back to the numerical model" in traditional hybrid experiments.

[0078] In this embodiment, displacement coordination means that the displacements of the numerical substructure 110 and the virtual experimental substructure 120 on the interaction boundary are basically the same, and force balance means that the nodal forces of the numerical substructure 110 and the virtual experimental substructure 120 on the interaction boundary are basically the same.

[0079] The underground structure hybrid test system considering formation loss provided in this embodiment of the invention determines the boundary node displacement of the interactive boundary based on the self-weight load increment corresponding to the current analysis step through the numerical substructure 110. Based on the virtual test substructure 120, the boundary node force is calculated and the node force is simulated based on the boundary node displacement and the current gravity. The concentrated force of each loading plate is determined based on the simulated node force value and the loading parameters of the loading plate to obtain the loading force of the actuator. The loading force and the corresponding displacement data are used as the current boundary conditions to perform parameter inversion on the actuator loading force and the corresponding displacement data to obtain the target material parameters. This updates the numerical model of the test substructure 130 and the corresponding boundary node force under the current boundary conditions. Based on the numerical substructure 110, the target unbalanced force is determined based on the updated boundary node force and the boundary node force corresponding to the previous analysis step to drive the next analysis step until the interactive boundary between the numerical substructure 110, the virtual test substructure 120 and the test substructure 130 satisfies displacement coordination and force balance. This system realizes the refined simulation of multi-field coupling mechanism under complex geological conditions and improves the accuracy of formation loss simulation.

[0080] In some embodiments, the interactive platform 140, the numerical substructure 110, and the virtual experimental substructure 120 are respectively connected to the interactive platform 140; the interactive platform 140 is used to enable the numerical substructure 110 and the virtual experimental substructure 120 to interact on target data, which includes boundary node forces, feedback forces, boundary node displacements, and feedback displacements.

[0081] In this embodiment, the experimental substructure 130 region in the numerical substructure 110 is not actually modeled. An interactive platform 140 needs to be introduced at the interactive boundary to replace part of the experimental substructure 130 in the calculation and analysis of the numerical substructure 110.

[0082] In this embodiment, the interaction platform 140 is used to coordinate data exchange between the numerical substructure 110 and the virtual experimental substructure 120, ensuring that data can be transmitted accurately and efficiently; wherein, the interaction platform 140 has the following functions:

[0083] (1) Data relay: Receive data from numerical substructure 110 and virtual experimental substructure 120 and send it to the corresponding receiver;

[0084] (2) Data format conversion: The data format is converted as needed to ensure that the numerical substructure 110 and the virtual experimental substructure 120 can correctly parse the data;

[0085] (3) Data synchronization: coordinate the data exchange between the numerical substructure 110 and the virtual experimental substructure 120 to ensure that the two can perform calculations synchronously.

[0086] Specifically, the numerical substructure 110 sends displacement data to the virtual test substructure 120 through the interactive platform 140; the virtual test substructure 120 transmits force data to the numerical substructure 110 through the interactive platform 140; the test substructure 130 sends actuator displacement data to the virtual test substructure 120 through the interactive platform 140, and simultaneously sends actuator force data to the virtual test substructure 120 through the interactive platform 140.

[0087] The underground structure hybrid test system considering formation loss provided in this embodiment of the invention provides a reliable data exchange channel between the numerical substructure 110 and the virtual test substructure 120 through the interactive platform 140, enabling the two to work together efficiently. Data accuracy and consistency are ensured through data format conversion and synchronization mechanisms.

[0088] In some embodiments, the interactive platform 140 includes OpenFresco and LabVIEW.

[0089] In this embodiment, the nodal displacements on the interactive boundary calculated by the numerical substructure 110 are transmitted to the experimental substructure 130 through an interactive platform 140 designed based on OpenFresco and LabVIEW.

[0090] Specifically, the connection method of the interactive system is as follows: numerical substructure 110 - OpenFresco - LabVIEW - virtual test substructure 120 - test substructure 130; among which, LabVIEW is a communication transmission plug-in, which is responsible for receiving the displacement data sent by the test unit defined by OpenFresco and transmitting it to the virtual test substructure 120, and receiving the feedback force sent by the virtual test substructure 120 and returning it to the test unit.

[0091] In addition, the virtual test substructure 120 includes a numerical model of the simulated test substructure 130 and a parameter inversion module 121, which is responsible for converting the displacement data transmitted by LabVIEW into force data and sending it to the test substructure 130, as well as receiving the feedback displacement data of the test substructure 130 and using it to invert the material parameters of the soil-structure model system in the test substructure 130, and then calculating the corresponding feedback force and returning it to LabVIEW.

[0092] In this embodiment, through the interactive platform 140 composed of OpenFresco and LabVIEW, the numerical substructure 110 can transmit the mechanical boundary conditions under each load level at the interactive boundary to the experimental substructure 130, enabling the experimental substructure 130 to load the physical model under that load level via actuators. Furthermore, after each level of mechanical boundary conditions is loaded, the experimental substructure 130 feeds back the new boundary mechanical conditions reflecting the nonlinear response of the physical model to the numerical substructure 110. The numerical substructure 110 then uses these new mechanical boundary conditions as a basis to solve for and transmit the mechanical boundary conditions under the next load level. This process is repeated until all loads are applied.

[0093] The underground structure hybrid test system considering ground loss provided in this embodiment of the invention, through the OpenFresco and LabVIEW design interaction platform 140, can realize bidirectional conversion of "displacement → force", solve the fundamental protocol conflict between OpenFresco and physical devices, and thus remove the limitation that the test substructure 130 cannot realize the process from pure soil loading to partial soil excavation and then to tunnel assembly.

[0094] In some embodiments, different stratigraphic properties of the numerical substructure 110 correspond to different compaction parameters; the soil of the numerical substructure 110 is simulated using four-node Quad elements in OpenSees, and the soil constitutive model is PDMY.

[0095] In this embodiment, numerical substructure 110 is the large-scale stratigraphic portion other than experimental substructure 130 (excluding the region of experimental substructure 130). The soil in numerical substructure 110 is simulated using four-node solid Quad elements in OpenSees, and the soil constitutive model is PDMY, with constitutive parameters taken from the official recommended values. The model is 120m wide and 89m high, with an overall mesh size of 1m × 1m and a local mesh size of 1m × 0.5m.

[0096] In this embodiment, considering that the soil density varies at different burial depths in actual strata—that is, the greater the burial depth, the greater the soil density—and that sandy soil often reaches a medium density within the range of 15–30 m, the strata properties are assigned a density according to different burial depths to more realistically simulate site conditions.

[0097] The underground structure hybrid test system considering ground loss provided in this embodiment of the invention uses a numerical substructure 110. The soil of the numerical substructure 110 is simulated using a four-node solid Quad element in OpenSees, and the soil constitutive model is PDMY. This system can more realistically simulate the disturbance effect of engineering activities on the ground, thereby significantly improving the engineering guidance value of the research.

[0098] In some embodiments, the test substructure 130 includes a reaction frame, a loading system, and a model box; wherein the loading system includes multiple actuator systems and a control system, each actuator system can independently extend and retract forward and backward, and the control system is used to control the motion state of the multiple actuator systems.

[0099] In this embodiment, the test substructure 130 needs to be designed according to the actual test conditions. The test device consists of three parts: a reaction frame, a loading system, and a model box; the specific settings of each part are as follows:

[0100] (1) The reaction frame has sufficient load-bearing capacity in both the horizontal and vertical directions, which can ensure the safe loading of the actuator.

[0101] (2) The loading system includes an actuator system and a control system; each actuator system consists of a loading plate, an actuator, and a steel connector connecting the two.

[0102] Each actuator has a steel connector that connects to the actuator at one end and passes through the side wall of the model box to connect to the loading plate inside the model box at the other end. Waterproof parts are installed at the intersection of the side wall and the rod. The gap between the horizontal loading plates and the guide beams on both sides of the vertical loading plates can prevent the loading plates from interfering with each other during loading. Therefore, each actuator system can extend and retract independently, thereby achieving non-uniform load loading under the coordinated control of the control system.

[0103] (3) The interior of the model box consists of front and rear side walls, bottom and loading plate, forming a 1m×1m×0.56m space, which is used to fill the stratum-structure scale model. The front of the model box is equipped with an observation window with a diameter of 30cm, which can be used to observe the mechanical response of the underground structure model, such as deformation, concrete cracking and component yielding.

[0104] The hybrid underground structure testing system considering ground loss provided in this invention includes a test substructure 130 comprising a reaction frame, a loading system, and a model box. The loading system includes multiple actuator systems and a control system. Each actuator system can independently extend and retract forward and backward. The control system controls the motion state of the multiple actuator systems. This design provides a stable and reliable testing environment for hybrid underground structure tests considering ground loss, enabling precise loading of the test model and real-time monitoring of test data. This helps improve the accuracy and reliability of test results, providing a more reliable basis for the research and design of underground structures.

[0105] In some embodiments, the test substructure 130 further includes a softening layer, the material of which has at least one of the following: plasticity, target yield strength, zero Poisson's ratio, and processability.

[0106] It should be noted that, due to limitations in current experimental technology, the experimental substructure 130 cannot continuously and sequentially realize the process from pure soil loading to partial soil excavation and then structural assembly within a single model box. To account for the influence of ground loss, the softening layer method was adopted in the experiment. Therefore, in the actual experiment, the model structure will exist from beginning to end and share the load with the soil. During the experiment, when applying the large-scale site soil self-weight load output from the numerical substructure 110, the plastic softening layer on the outside of the structure shrinks and deforms significantly compared to the soil. By controlling the material properties of the softening layer, the expected ground loss can be generated.

[0107] Specifically, from an experimental perspective, this embodiment uses the following criteria for selecting the softening layer material:

[0108] (1) It has plasticity to prevent large springback under unloading conditions;

[0109] (2) It has a suitable yield strength, which prevents large deformation from occurring in the plastic stage at the beginning of the test, and also prevents failure to enter the plastic stage after the test loading is completed.

[0110] (3) Poisson's ratio is zero, ensuring that no planar deformation occurs under the pressure of the surrounding soil;

[0111] (4) It has good processing performance and is easy to manufacture according to needs.

[0112] Based on the above criteria, expanded polystyrene (EPS) foam was selected as the softening layer material in this embodiment.

[0113] The underground structure hybrid test system considering formation loss provided in this embodiment of the invention further improves the accuracy of physical simulation of formation loss by setting up a test substructure 130 that also includes a softening layer. The material of the softening layer has the following characteristics: plasticity, target yield strength, zero Poisson's ratio and workability.

[0114] In some embodiments, the test substructure 130 further includes: a soil-structure scaled-down model, which includes model soil and a model box; wherein the model soil is standard sand, a rubber membrane is attached between the model soil and the side wall of the model box, and the outer surface of the rubber membrane is covered with a PTFE membrane and petroleum jelly.

[0115] In this embodiment, taking into account the internal dimensions of the model box and the loading capacity of the actuator, the scale ratio of the test substructure 130 can be taken as 1:12 (this scale ratio can also be used as a reference standard for the above similarity coefficient value) to make a scaled-down soil-structure model. At the same time, geometric dimensions, material stress, and material strain are selected as basic physical quantities, and the similarity ratio of material stress and material strain is taken as 1:1.

[0116] In this embodiment, the model soil in the experimental substructure 130 is standard sand; specifically, the model soil is filled using the sand rain method, and the sand compaction is determined to be 73%, corresponding to a density of 1.54 g / cm³. 3 The friction angle is 34.4°. To construct a scaled-down model of underground structures (such as shield tunnels and rectangular subway stations), micro-particle concrete and galvanized iron wire are used to simulate concrete and steel reinforcement materials in reinforced concrete, respectively, while retaining the detailed structural features of component joints (such as joints and bolts). This scaled-down model is used to reproduce the initial nonlinear response state of existing underground structures during the service stage, and further simulate the damage evolution and failure mechanism that may occur under subsequent construction disturbances or seismic loads.

[0117] In this embodiment, during the test, in order to minimize the friction between the model soil and the side wall of the model box, a layer of rubber membrane was attached to the loading plate and side wall of the test substructure 130. The outer surface of the rubber membrane was covered with PTFE membrane and coated with Vaseline. The same rubber membrane was used to wrap the sand to prevent sand leakage, so that the sides of the two rubber membranes with PTFE membrane and Vaseline were in contact with each other.

[0118] The underground structure hybrid test system considering ground loss provided in this invention effectively reduces friction between the model soil and the model box by employing standard sand, rubber membrane, PTFE membrane, and petroleum jelly, thereby mitigating the impact of boundary effects on the test results. This helps improve the accuracy and reliability of the test results, providing a more reliable basis for the research and design of underground structures.

[0119] The control method of the underground structure hybrid test system considering formation loss provided by the present invention is described below. The control method of the underground structure hybrid test system considering formation loss described below can be referred to in correspondence with the underground structure hybrid test system considering formation loss described above.

[0120] Figure 2 This is a flowchart illustrating the control method of the underground structure hybrid test system considering formation loss provided by the present invention, as shown below. Figure 2 As shown, the control method for the underground structure hybrid test system considering formation loss includes the following steps:

[0121] Step 210: Based on the numerical substructure, in multiple analysis steps of the formation gravity loading process, determine the boundary node displacement of the interactive boundary according to the self-weight load increment corresponding to the current analysis step.

[0122] In this step, in this embodiment, the interaction boundary can be a virtual interface for data transfer between the numerical substructure and the experimental substructure in the hybrid experimental system, used to achieve the coordinated coupling of physical experiments and numerical simulations.

[0123] In this embodiment, the interaction boundary is not a structural entity, but a data exchange plane defined by the interaction platform.

[0124] In this embodiment, there is a data channel for numerical to physical direction transmission at the interaction boundary. For example, the interaction plane can transmit the boundary point displacement calculated by the numerical substructure, i.e., the boundary node displacement.

[0125] In this embodiment, the numerical substructure is a computational model constructed by numerical simulation software to simulate large-scale stratigraphic mechanical behavior. The numerical substructure does not include the region where the experimental substructure is located and is used to exchange data with the experimental substructure at the interaction boundary.

[0126] In this embodiment, the numerical substructure is also used to calculate the stress state of the formation in different analysis steps: the numerical substructure calculates the stress distribution of the formation according to the self-weight load increment corresponding to the current analysis step, and based on the calculated stress distribution, the numerical substructure can determine the displacement of each node on the interactive boundary connected to the test substructure.

[0127] Specifically, by applying the self-weight load of the current analysis step to the numerical substructure and starting the calculation iteration based on the convergence result of the previous analysis step, in each iteration, the numerical substructure transmits the calculated boundary node displacements to the virtual test substructure or test substructure of the underground structure hybrid test system considering ground loss through the interactive platform.

[0128] It should be noted that the underground structure hybrid test considering ground loss in this embodiment includes an initial ground gravity loading stage and a loading stage for disturbances such as adjacent construction or earthquakes during the operation period of the existing underground structure.

[0129] This embodiment can divide the initial formation gravity load loading process into equal parts. n Each analysis step (e.g., n (Take 100); at the same time, in order to avoid distortion in the simulation of formation loss, the softening layer needs to be progressively compressed.

[0130] Step 220: Calculate the boundary node forces based on the boundary node displacements and current gravity according to the virtual test substructure, obtain the simulated values ​​of the node forces based on the boundary node forces and similarity coefficients, and determine the concentrated forces of each loading plate based on the simulated values ​​of the node forces and the loading parameters of the loading plates.

[0131] In this step, the virtual experimental substructure consists of a numerical model used to simulate the behavior of the experimental substructure and to perform necessary transformations and calculations to achieve synergy between numerical simulation and physical experiment.

[0132] In this embodiment, the virtual test substructure can receive the boundary node displacement transmitted by the numerical substructure, calculate the corresponding boundary node force according to its own numerical model, and perform numerical simulation of the boundary node force, converting it into a concentrated force acting on the loading plate.

[0133] In this embodiment, the virtual test substructure can update the numerical model of the test substructure and recalculate the boundary node forces under the current boundary conditions.

[0134] Specifically, the virtual test substructure calculates the response based on the received boundary node displacement and the current self-weight (the response is: soil compression caused by self-weight load → affecting the calculation of boundary node forces), outputs the nodal forces, and then transmits them back to the numerical subsystem via the interactive platform.

[0135] Step 230: Based on the experimental substructure, apply concentrated force to the stratum-tunnel model through the actuator, obtain the actuator loading force and corresponding displacement data, and use the actuator loading force and corresponding displacement data as the current boundary conditions.

[0136] In this step, the test substructure is an actual physical model, which includes soil layers, tunnel structure, and loading device, etc.

[0137] In this embodiment, the experimental substructure includes the following functions:

[0138] (1) Bearing concentrated force loading: The test substructure bears the concentrated force loading transmitted by the virtual test substructure through the actuator.

[0139] (2) Obtaining the actuator loading force and corresponding displacement data: During the loading process, the test substructure will monitor the actuator loading force and corresponding displacement data in real time and feed these data back to the virtual test substructure.

[0140] In this embodiment, the experimental substructure loads the stratum-tunnel model system through an actuator. After the nodal forces are loaded, the material parameters of the stratum-tunnel model system under the current boundary conditions are inverted based on the actuator loading force and the corresponding displacement.

[0141] Step 240: Perform parameter inversion on the actuator loading force and corresponding displacement data based on the parameter inversion module to obtain the target material parameters of the test substructure under the current boundary conditions.

[0142] In this step, the parameter inversion module is used to correct the numerical model of the test substructure. Specifically, it analyzes the test data of the test substructure to invert the material parameters of the soil layer and structure in the test substructure, thereby improving the accuracy of the numerical model.

[0143] The parameter inversion module specifically includes the following functions:

[0144] (1) Receive actuator loading force and displacement data: The parameter inversion module receives the actuator loading force and corresponding displacement data sent by the test substructure.

[0145] (2) Parameter inversion: The parameter inversion module takes the actuator loading force and corresponding displacement data as the optimization target, uses the numerical model of the test substructure as the calculation kernel, and uses optimization algorithms (such as genetic algorithm, particle swarm algorithm, etc.) to invert the material parameters of the soil layer and structure.

[0146] (3) Obtain target material parameters: The parameter inversion module outputs the target material parameters of the soil-structure model system in the test substructure under the current boundary conditions.

[0147] In this embodiment, the material parameters of the stratum-tunnel model under the current boundary conditions include soil parameters and softening layer parameters; the stratum-tunnel model is the physical entity of the test substructure (including the stratum part, the tunnel part, and the softening layer), specifically a physical simulation device constructed at a strict scale to reproduce the mechanical effects of stratum loss on the tunnel structure under controlled conditions.

[0148] Among them, soil parameters include elastic modulus, Poisson's ratio, friction angle or plastic hardening coefficient, etc.; softening layer parameters include yield stress, compression modulus or Poisson's ratio, etc.

[0149] Step 250: Based on the virtual test substructure, update the numerical model of the test substructure according to the target material parameters, and update the corresponding boundary nodal forces under the current boundary conditions; send the updated boundary nodal forces to the numerical substructure.

[0150] In this step, in this embodiment, after updating the virtual test substructure by using physical parameters (i.e., target material parameters) that reflect the nonlinear response of the test substructure, the boundary force of the virtual test substructure under the boundary displacement is recalculated and fed back to the numerical substructure, thereby achieving smooth interaction.

[0151] In this embodiment, since the nodal forces on the interaction boundary of the experimental substructure are the same as those on the numerical substructure, they cannot interact. In order for the interaction to proceed smoothly, the nodal forces on the interaction boundary containing the nonlinear response of the experimental substructure need to be returned to the numerical substructure.

[0152] In this embodiment, the numerical model of the virtual experimental substructure was corrected, which can more accurately simulate the real behavior of the experimental substructure. The updated boundary node forces also more realistically reflect the constraint effect of the experimental substructure on the surrounding strata, providing more accurate boundary conditions for the subsequent calculation of the numerical substructure.

[0153] Step 260: Based on the numerical substructure, determine the target unbalanced force according to the updated boundary node forces and the boundary node forces corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual experimental substructure and the experimental substructure satisfies displacement coordination and force balance.

[0154] Specifically, after receiving the updated boundary node forces from the virtual test substructure, the numerical substructure needs to calculate the target unbalanced force based on the difference between the node force and the node force corresponding to the previous analysis step. This unbalanced force will be used as the driving force to drive the numerical substructure to perform the next calculation until the entire hybrid test system reaches a state of displacement coordination and force balance, which can achieve the coordinated convergence of numerical simulation and physical experiment, and ensure the accuracy and reliability of the hybrid test results.

[0155] In this embodiment, the process of driving the analysis step through unbalanced force includes: taking the sum of the unbalanced force calculated in the k-th analysis step and the initial self-weight load corresponding to the (k+1)-th analysis step as the self-weight load input for the (k+1)-th analysis step, thus realizing the technical chain of force difference at the current analysis step node → calculation of unbalanced force → correction of self-weight load for the next analysis step, which can solve the problem of "physical nonlinearity cannot be fed back to the numerical model" in traditional hybrid experiments.

[0156] In this embodiment, displacement coordination means that the displacements of the numerical substructure and the virtual experimental substructure are basically the same on the interaction boundary, and force balance means that the nodal forces of the numerical substructure and the virtual experimental substructure are basically the same on the interaction boundary.

[0157] The control method of the underground structure hybrid test system considering formation loss provided by this invention determines the boundary node displacement of the interaction boundary based on the self-weight load increment corresponding to the current analysis step through a numerical substructure. Based on the virtual test substructure, the boundary node force is calculated and simulated based on the boundary node displacement and the current gravity. The concentrated force of each loading plate is determined based on the simulated node force value and the loading parameters of the loading plate to obtain the loading force of the actuator. The loading force and the corresponding displacement data are used as the current boundary conditions to perform parameter inversion on the actuator loading force and the corresponding displacement data to obtain the target material parameters. This updates the numerical model of the test substructure and the corresponding boundary node force under the current boundary conditions. Based on the numerical substructure, the target unbalanced force is determined based on the updated boundary node force and the boundary node force corresponding to the previous analysis step to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual test substructure, and the test substructure satisfies displacement coordination and force balance. This system realizes the refined simulation of multi-field coupling mechanism under complex geological conditions and improves the accuracy of formation loss simulation.

[0158] Figure 3 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 3As shown, the electronic device may include: a processor 310, a communications interface 320, a memory 330, and a communications bus 340, wherein the processor 310, the communications interface 320, and the memory 330 communicate with each other through the communications bus 340. The processor 310 can call logic instructions in the memory 330 to execute a control method for a hybrid underground structure test system considering ground loss. This method includes: determining the boundary node displacements of interactive boundaries based on the self-weight load increment corresponding to the current analysis step in multiple analysis steps of the ground gravity loading process using a numerical substructure; calculating the boundary node forces based on the boundary node displacements and the current gravity using a virtual test substructure, obtaining simulated values ​​of the node forces based on the boundary node forces and similarity coefficients, and determining the concentrated forces of each loading plate based on the simulated values ​​of the node forces and the loading parameters of the loading plates; applying concentrated forces to the ground-tunnel model via actuators using the test substructure, obtaining actuator loading forces and corresponding displacement data, and using the actuator loading forces and corresponding displacement data as the current boundary conditions; performing parameter inversion on the actuator loading forces and corresponding displacement data using a parameter inversion module to obtain the target material parameters of the test substructure under the current boundary conditions; updating the numerical model of the test substructure based on the target material parameters using the virtual test substructure, and updating the corresponding boundary node forces under the current boundary conditions; and sending the updated boundary node forces to the numerical substructure.

[0159] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0160] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method for the underground structure hybrid test system considering ground loss provided by the above methods. The method includes: determining the boundary node displacement of the interactive boundary based on the self-weight load increment corresponding to the current analysis step in multiple analysis steps of the ground gravity loading process based on the numerical substructure; calculating the boundary node force based on the boundary node displacement and the current gravity based on the virtual test substructure, and obtaining the node force based on the boundary node force and the similarity coefficient. The system simulates force values ​​and determines the concentrated force of each loading plate based on the simulated nodal force values ​​and the loading parameters of the loading plates. It then applies concentrated forces to the stratum-tunnel model via actuators based on the experimental substructure, obtaining actuator loading forces and corresponding displacement data, and using these data as the current boundary conditions. Finally, it performs parameter inversion on the actuator loading forces and corresponding displacement data using the parameter inversion module to obtain the target material parameters of the experimental substructure under the current boundary conditions. Based on the virtual experimental substructure, it updates the numerical model of the experimental substructure according to the target material parameters and updates the corresponding boundary nodal forces under the current boundary conditions. The updated boundary nodal forces are then sent to the numerical substructure.

[0161] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0162] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hybrid test system for underground structures considering formation losses, characterized in that, include: Numerical substructure is used to determine the boundary node displacement of the interactive boundary based on the self-weight load increment corresponding to the current analysis step in multiple analysis steps during the formation gravity loading process. The virtual test substructure is used to calculate the boundary node force based on the boundary node displacement and the current gravity, obtain the simulated value of the node force based on the boundary node force and the similarity coefficient, and determine the concentrated force of each loading plate based on the simulated value of the node force and the loading parameters of the loading plate. The test substructure is used to apply the concentrated force to the stratum-tunnel model through the actuator, obtain the actuator loading force and the corresponding displacement data, and use the actuator loading force and the corresponding displacement data as the current boundary conditions. The virtual test substructure includes a parameter inversion module, which is used to perform parameter inversion on the actuator loading force and corresponding displacement data to obtain the target material parameters of the test substructure under the current boundary conditions. The virtual test substructure is also used to update the numerical model of the test substructure according to the target material parameters, and to update the boundary node forces corresponding to the current boundary conditions; Send the updated boundary node forces to the numerical substructure; The numerical substructure is also used to determine the target unbalance force based on the updated boundary node force and the boundary node force corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual test substructure and the test substructure satisfies displacement coordination and force balance.

2. The underground structure hybrid test system considering formation loss according to claim 1, characterized in that, The system also includes: An interactive platform is provided, wherein the numerical substructure and the virtual experimental substructure are respectively connected to the interactive platform; the interactive platform is used to enable the numerical substructure and the virtual experimental substructure to interact with target data, wherein the target data includes boundary node forces, feedback forces, boundary node displacements, and feedback displacements.

3. The underground structure hybrid test system considering formation loss according to claim 2, characterized in that, The interactive platforms include OpenFresco and LabVIEW.

4. The underground structure hybrid test system considering formation loss according to claim 1, characterized in that, Different stratigraphic properties of the numerical substructure correspond to different density parameters; The soil in the numerical substructure was simulated using four-node Quad elements in OpenSees, and the soil constitutive model was PDMY.

5. The underground structure hybrid test system considering formation loss according to claim 1, characterized in that, The experimental substructure includes a reaction frame, a loading system, and a model box; The loading system includes multiple actuator systems and a control system. Each actuator system can extend and retract independently, and the control system is used to control the motion state of the multiple actuator systems.

6. The underground structure hybrid test system considering formation loss according to claim 1, characterized in that, The experimental substructure includes: The softening layer is made of a material that has the following characteristics: plasticity, target yield strength, zero Poisson's ratio, and processability.

7. The underground structure hybrid test system considering formation loss according to claim 6, characterized in that, The experimental substructure also includes: A soil-structure scaled-down model, which includes model soil and a model box; The model soil is made of standard sand, and a rubber membrane is attached between the model soil and the side wall of the model box. The outer surface of the rubber membrane is covered with PTFE film and petroleum jelly.

8. A control method for a hybrid test system of underground structures considering formation losses, characterized in that, include: Based on the numerical substructure, in multiple analysis steps of the formation gravity loading process, the boundary node displacement of the interactive boundary is determined according to the self-weight load increment corresponding to the current analysis step. Based on the virtual test substructure, the boundary node forces are calculated according to the boundary node displacements and the current gravity. The simulated values ​​of the node forces are obtained according to the boundary node forces and the similarity coefficients. The concentrated forces of each loading plate are determined according to the simulated values ​​of the node forces and the loading parameters of the loading plates. Based on the experimental substructure, the concentrated force is applied to the stratum-tunnel model through the actuator, the actuator loading force and the corresponding displacement data are obtained, and the actuator loading force and the corresponding displacement data are used as the current boundary conditions. Based on the parameter inversion module, the loading force and corresponding displacement data of the actuator are inverted to obtain the target material parameters of the test substructure under the current boundary conditions. Based on the virtual test substructure, the numerical model of the test substructure is updated according to the target material parameters, and the boundary nodal forces corresponding to the current boundary conditions are updated; Send the updated boundary node forces to the numerical substructure; Based on the numerical substructure, the target unbalance force is determined according to the updated boundary node force and the boundary node force corresponding to the previous analysis step, so as to drive the next analysis step until the interaction boundary between the numerical substructure, the virtual test substructure and the test substructure satisfies displacement coordination and force balance.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the control method for the underground structure hybrid test system considering formation loss as described in claim 8.

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, it implements the control method of the underground structure hybrid test system considering formation loss as described in claim 8.

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