A reconfigurable tunnel engineering pilot simulation system and method based on fabricated components

Abstract

The application discloses a reconfigurable tunnel engineering pilot simulation system and method based on fabricated components, and relates to the technical field of tunnel engineering testing and simulation. The system is composed of standardized lining rings and preset working condition function modules, and is matched with a reconfiguring adaptive module to realize quick disassembly, replacement and assembly. In combination with a multi-module collaborative architecture, the system solves the problems of poor controllability and difficult working condition adjustment of traditional models. The application has the advantages that: by adopting the factory-prepared standardized lining ring modules and various types of preset working condition function modules, and with the help of the precise positioning guide mechanism and locking fixing mechanism of the reconfiguring adaptive module, the quick disassembly, replacement and assembly of different modules are realized, and the problems of uncontrollable defect simulation and the need for overall reconstruction for working condition adjustment of traditional cast-in-place tunnel pilot models are solved. Different disease working conditions such as cracks, cavities and leakage and new material testing scenes can be flexibly switched without large-area chiseling.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering testing and simulation technology, specifically to a pilot-scale simulation system and method for reconfigurable tunnel engineering based on prefabricated components. Background Technology

[0002] In the field of tunnel and underground engineering, pilot-scale simulation is a key link connecting theoretical research and practical engineering applications. Its core value lies in providing reliable data support for tunnel structure design optimization, verification of new materials and processes, and research and development of disease prevention and control technologies by constructing a test platform that closely resembles real working conditions. As transportation infrastructure construction develops towards complex geological conditions, large spans, and deep excavation, the technical challenges faced by tunnel engineering are becoming increasingly prominent, placing higher demands on the accuracy, flexibility, and efficiency of pilot-scale simulation. Furthermore, traditional cast-in-place tunnel pilot-scale models are limited by structural fixedness. Each model needs to be cast as a whole according to specific working conditions, which not only occupies a large area, but also requires the construction of multiple independent models when simulating different structural forms or types of defects. This leads to a significant increase in the demand for dedicated test space. However, in actual scientific research scenarios, most laboratories and test bases have limited dedicated space, making it difficult to deploy multiple fixed models with different working conditions at the same time. This increases the cost of site planning and construction, and also fails to meet the needs of researchers to conduct multiple sets of comparative tests in a limited space, further restricting the popularization and efficient application of tunnel engineering pilot-scale simulation technology. Existing pilot-scale simulations of tunnel engineering mainly rely on fixed models constructed with cast-in-place concrete, which has certain drawbacks. First, the simulation parameters of traditional cast-in-place models are uncontrollable, and adjustments to working conditions require complete demolition and reconstruction, resulting in time-consuming and labor-intensive repeated construction. Furthermore, the consistency and comparability of experimental data are insufficient. Second, the fixed model structure leads to poor site adaptability, making it impossible to simulate various structural and defect combinations within a limited space. It also lacks practical teaching and intuitive demonstration functions, limiting its application scenarios. Therefore, we propose a reconfigurable pilot-scale simulation system and method for tunnel engineering based on prefabricated components. Summary of the Invention

[0003] The purpose of this invention is to provide a pilot-scale simulation system and method for reconfigurable tunnel engineering based on prefabricated components.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components, the pilot-scale simulation system comprising the following modules: Basic support module: Provides a stable bearing foundation and standard connection interface, which fixes the standardized lining ring module and the pre-set working condition function module to itself, ensuring the overall structural stability of the system; Standardized lining ring module: It is composed of multiple arc-shaped standard lining blocks to form a complete tunnel ring. According to the tunnel structure layers, it is divided into an initial support simulation ring, a waterproof layer simulation ring, and a secondary lining simulation ring to simulate the structural morphology and force transmission path of a healthy section of the tunnel. Pre-set working condition function module: It is made in the factory with the same external geometry and connection interface as the standardized lining block. It can directly replace the corresponding standard block in the standardized lining ring module to simulate working conditions such as tunnel cracks, voids, leakage and material variation, and has plug-and-play characteristics. Loading simulation module: Simulates external load environments such as tunnel surrounding rock stress and water pressure, and adjusts the loading force and loading range according to the instructions of the system control module to match the actual engineering load scenario; Sensing and monitoring module: Collects strain, displacement and seepage pressure response data of the simulated main structure through built-in sensors. The simulated main structure is the overall structure assembled from the standardized lining ring module and the pre-set working condition function module, providing raw data support for experimental analysis. Data acquisition module: Receives data transmitted from the sensor monitoring module, performs preliminary processing such as filtering and format conversion to ensure data integrity and validity; System control module: As the core of system control, it receives processed data from the data acquisition module, combines it with the preset parameters of the test plan, and generates loading control commands and module reconfiguration commands to realize automated control of the test process; Reconfiguration and adaptation module: Receives reconfiguration instructions from the system control module, and based on precise positioning and locking mechanisms, enables the rapid disassembly, replacement, and assembly of standardized lining blocks and pre-set working condition functional modules, ensuring the structural accuracy and connection firmness after module replacement.

[0005] As a further aspect of the present invention: the basic support module includes a bearing foundation and pre-embedded connection components. The pre-embedded connection components are one or more combinations of pre-embedded steel plates, bolt hole groups, or socket structures. The layout positions of the pre-embedded connection components correspond one-to-one with the connection interfaces of the standardized lining ring module and the pre-set working condition function module. The layout spacing is staggered from the splicing joint positions of the standard lining blocks. The bearing foundation is formed by casting reinforced concrete with a casting thickness of not less than 500mm. A double-layer steel mesh is set inside the foundation with a steel mesh spacing of 150-200mm and a steel bar diameter of not less than 16mm to ensure that the bearing strength of the bearing foundation is not lower than the design strength standard of the actual tunnel engineering foundation.

[0006] As a further aspect of the present invention: in the standardized lining ring module, the initial support simulation ring is composed of precast simulated shotcrete blocks and precast steel arch units alternately spliced ​​together. The cross-sectional shape of the precast steel arch units is either I-shaped or H-shaped, with a spacing of 500-800mm. The waterproof layer simulation ring is a frame-type openable structure, with the frame made of aluminum alloy and an opening angle range of 0-180°. The geotextile laid inside has a basis weight of 300-400g / m². 2 The waterproof membrane is 1.5-2.0mm thick and is fixed to the frame by pressure strips. The secondary lining simulation ring is made of precast reinforced concrete blocks. The precast blocks are equipped with double-layer bidirectional steel bars with a spacing of 100-150mm and a diameter of 12-16mm. The high-strength mechanical connectors are one or more combinations of high-strength bolts, prestressed cables, or mortise and tenon structures. The connectors are made of high-strength alloy steel with a tensile strength of not less than 800MPa. The connection surface is coated with a sandblasted and rust-removed anti-slip and wear-resistant coating with a thickness of 50-100μm.

[0007] As a further aspect of the present invention: the pre-set working condition function module includes at least two combinations of a crack module, a concrete defect module, a back defect module, a leakage module, a material testing module, and a strength variation module, wherein the equivalent working width of the crack in the crack module is calculated based on the following formula: ; in, The equivalent working width of the crack (unit: mm) is the actual effective width of the crack during the test. The initial width of the crack during factory prefabrication (unit: mm) is precisely controlled by high-precision prefabrication molds, with an error not exceeding ±0.01 mm. This is the temperature correction factor for crack width (unit: 1 / ℃), used to correct for the effect of ambient temperature changes on crack width. It is determined based on the difference between the test ambient temperature and the prefabrication ambient temperature, and its value ranges from 0.001 to 0.01 / ℃. The value represents the difference between the test ambient temperature and the pre-fabricated ambient temperature (unit: °C). A positive value is taken when the test ambient temperature is higher than the pre-fabricated ambient temperature, and a negative value is taken when it is lower. The equivalent volume of the void in the underlying defect module is calculated based on the following formula: ; in, Equivalent volume of the cavity (unit: m) 3 That is, to simulate the actual effective void volume behind the lining. The cross-sectional area of ​​the pre-set cavity on the back of the module (unit: m²) 2 It is formed by prefabrication of molds and has a fixed value with an error not exceeding ±0.001m.2 , The axial length (in meters) of the pre-set working condition function module is completely consistent with the axial length of the standardized lining block, with an error not exceeding ±0.005 meters. This is the void filling coefficient, with a value range of 0 ≤ ≤1, based on the control of the inflation volume of the inflatable airbag pre-embedded in the back of the defect module and the filling volume of the removable filler, when It was in a completely hollow state at the time. At time 0, there are no voids (i.e., the filler completely fills the preset void area).

[0008] As a further aspect of the present invention: the loading simulation module includes a hydraulic loading unit, a load distribution component, and a pressure feedback sensor, and the ground stress value simulated by the loading simulation module is calculated based on the following formula: ; in, The simulated in-situ stress value (unit: MPa) represents the equivalent surrounding rock stress applied to the simulated main structure. This is a correction factor for the surrounding rock level, determined based on the simulated surrounding rock level, for Class I surrounding rock. Class II surrounding rock Class III surrounding rock Class IV surrounding rock Class V surrounding rock , To simulate the unit weight of the surrounding rock (unit: kN / m³) 3 The value is selected based on the surrounding rock type of the actual tunnel project, and the range is 18-26 kN / m. 3 , To simulate the tunnel's burial depth (unit: m), the value was determined based on the simulated working conditions set in the test plan, with a range of 5-100 m. The loading efficiency coefficient, considering the mechanical efficiency and load transfer loss of the hydraulic loading unit, is taken in the range of 0.9-1.0. The hydraulic loading unit adopts a servo hydraulic control system, and the loading rate is continuously adjustable in the range of 0.01-0.1MPa / s, with a pressure control accuracy of ±0.01MPa. The load distribution component adopts a distributed arc-shaped pressure plate structure, and the curvature of the pressure plate is completely in contact with the outer arc surface of the simulated main structure, with a contact gap of no more than 0.5mm. The pressure plate is made of Q355 steel with a thickness of 20-30mm.

[0009] As a further aspect of the present invention: the sensing and monitoring module includes strain gauges, displacement gauges, piezometers, and temperature sensors. All sensors have a measurement accuracy class of not less than 0.1. The strain gauges are foil strain gauges with a sensitivity coefficient of 2.0-2.2, and are adhered to the inner and outer surfaces of the standardized lining blocks and the pre-set working condition functional modules. At least three strain gauges are arranged at each key section of the arch crown, arch waist, sidewalls, and arch bottom. Strain gauges at the same section are evenly distributed circumferentially with a spacing of 30-50 mm to achieve data redundancy verification. The displacement gauges are wire-type displacement sensors with a measurement range of 0-50 mm and a resolution of 0.00. 1mm gauges are deployed along the axial and radial directions of the main structure of the tunnel simulation. One gauge is deployed every 2m along the axial direction, and one gauge is deployed at the arch crown, arch waist, and sidewall positions of each key section in the radial direction. The piezometers are vibrating wire piezometers with a measurement range of 0-2MPa and a resolution of 0.001MPa. They are deployed only at the inlet and outlet positions of the preset leakage channels of the leakage module. The temperature sensors are platinum resistance temperature sensors with a measurement range of -20-80℃ and a resolution of 0.1℃. They are deployed around the main structure of the simulation and inside the preset working condition function module to collect the ambient temperature and the internal temperature of the module.

[0010] As a further aspect of the present invention: the data acquisition module includes a data acquisition card, a signal amplifier, and a data buffer unit. The signal amplifier is a programmable gain amplifier with a gain that can be adjusted in stages from 100 to 1000 times, amplifying the weak electrical signal output by the sensing and monitoring module to the range that the data acquisition card can recognize, while suppressing environmental electromagnetic interference. The data acquisition card is a multi-channel synchronous acquisition card with no fewer than 32 channels, an adjustable sampling frequency from 10 to 100 Hz, and a 16-bit sampling resolution to ensure the synchronization and accuracy of data acquisition. The data buffer unit uses a solid-state drive with a storage capacity of no less than 100 GB, capable of continuously storing all monitoring data from at least 10 complete experiments. The data storage format is a general CSV format, and each data file contains a data acquisition timestamp, sensor number, measured value, and data checksum information, facilitating subsequent data export, analysis, and traceability.

[0011] As a further aspect of the present invention: the system control module includes an industrial control computer, control software, and a signal output interface. The industrial control computer serves as the control core and supports visual setting of test parameters. The control software has functions for setting test parameters, real-time control of the loading process, real-time data display, abnormal alarm, and data storage. The test parameter settings include loading mode, loading rate, target load value, and data acquisition frequency. When the structural response data collected by the sensing and monitoring module exceeds a preset threshold, the control software automatically triggers an alarm and simultaneously controls the loading simulation module to stop loading through the signal output interface, and saves all current test data. The data transmission rate of the signal output interface is not less than 100Mbps to ensure real-time response to control commands.

[0012] As a further aspect of the present invention: the reconfiguration and adaptation module includes a positioning and guiding mechanism, a locking and fixing mechanism, and a position detection sensor. The positioning and guiding mechanism adopts a structure in which a tapered positioning pin and a positioning hole are matched. The taper of the positioning pin is 1:50-100, and the positioning accuracy is not less than ±0.1mm, ensuring that the coaxiality error between the standardized lining block and the preset working condition function module after replacement does not exceed 0.5mm, and the circumferential misalignment error does not exceed 0.3mm. The locking and fixing mechanism adopts an electric bolt tightener, and the tightening torque can be continuously adjusted within the range of 50-500N·m, with a torque control accuracy of ±1N·m. The torque value is monitored in real time during the tightening process, and the tightening is automatically stopped when the torque reaches the preset value, while simultaneously feeding back a locking completion signal. The position detection sensor adopts a laser displacement sensor with a measurement range of 0-100mm and a resolution of 0.001mm. It monitors the position deviation during the module replacement process in real time, and issues an alarm signal when the deviation exceeds the allowable range to prevent the locking operation.

[0013] The system employs standardized interfaces and protocols for data interaction between its modules, ensuring data transmission stability and compatibility. For data interfaces, the system control module communicates with the loading simulation module and the reconfiguration adaptation module via an RS485 industrial bus interface, with a data transmission rate of at least 100Mbps, supporting stable long-distance communication. The data acquisition module and the sensing monitoring module achieve multi-channel synchronous data reception via an Ethernet interface, compatible with both analog and digital signal inputs. External terminals interact with the system control module using an Ethernet TCP / IP interface, supporting remote parameter configuration and data export. Regarding data format, real-time acquired structural response data is transmitted in JSON format, containing data... The data includes the timestamp, unique sensor ID, type of measured physical quantity, original measurement value, and data check code. Offline data storage uses the common CSV format, supplemented with module number and test condition number fields to facilitate data traceability and cross-platform analysis. In terms of control protocol, the loading control command and module reconfiguration command are encapsulated using the Modbus-RTU standard protocol. The command frame contains address code, function code, data segment, and check code. The loading control command data segment clearly specifies the loading mode, target load, and rate parameters. The module reconfiguration command data segment contains key information such as module type, replacement position, and locking torque threshold. The protocol supports command retransmission and error feedback mechanisms to ensure reliable execution of control commands.

[0014] In addition, this application also provides a pilot-scale simulation method for reconfigurable tunnel engineering based on prefabricated components, the pilot-scale simulation method comprising the following steps: S1. Assemble the standardized lining ring: Using the standard connection interface provided by the basic support module of the pilot simulation system, assemble multiple arc-shaped standard lining blocks to form a complete tunnel ring, including the initial support simulation ring, the waterproof layer simulation ring, and the secondary lining simulation ring. S2. Install the pre-set working condition function module: Through the reconstruction and adaptation module of the pilot simulation system, replace the corresponding standard block in the standardized lining ring with the pre-made pre-set working condition function module in the factory to simulate tunnel cracks, voids, leakage and material variation defects. S3. Apply external load: Using the loading simulation module of the pilot-scale simulation system, simulate the external load environment of surrounding rock stress and water pressure according to the test plan, and load the assembled simulated main structure. S4. Collect structural response data: Collect strain, displacement and seepage pressure data of the simulated main structure through the sensing and monitoring module of the pilot simulation system; S5. Data processing and loading control: The data acquisition module of the pilot-scale simulation system receives and processes the acquired data, and the system control module generates loading control commands in combination with preset experimental parameters to achieve automated control of the loading process. S6. Reconstruction and Replacement Module: According to the test requirements, the standardized lining blocks and the preset working condition functional modules are quickly disassembled, replaced and reassembled through the positioning and locking mechanism of the reconstruction and adaptation module of the pilot simulation system.

[0015] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows: 1. This invention utilizes factory-prefabricated standardized lining ring modules and various types of pre-set working condition functional modules. Through the precise positioning and guiding mechanism and locking mechanism of the reconfigurable and adaptable modules, it enables rapid disassembly, replacement, and assembly of different modules. This solves the problems of uncontrollable defect simulation and the need for overall reconstruction for working condition adjustments in traditional cast-in-place tunnel pilot-scale models. It allows for flexible switching between different defect conditions such as cracks, voids, and leaks, as well as new material testing scenarios, without the need for large-scale excavation. Simultaneously, the factory prefabrication process ensures the consistency and accuracy of defect parameters. Combined with the collaborative work of the sensing and monitoring modules and data acquisition modules, it effectively improves the scientific rigor and comparability of experimental data, significantly reducing the time and resource consumption of repeated construction, achieving a flexible, efficient, economical, and practical pilot-scale test.

[0016] 2. This invention solves the problems of poor site adaptability and lack of teaching demonstration and practical training functions of traditional models by constructing an integrated collaborative architecture of basic support module, loading simulation module, sensing and monitoring module and system control module. It combines the plug-and-play characteristics of pre-set working condition function module with the rapid reconfiguration capability of reconfigurable and adaptable module. By using standardized lining ring modules to assemble healthy sections according to the tunnel structure hierarchy, and replacing the pre-set working condition function module, various tunnel structures and defect combinations can be simulated in a limited space, providing an efficient comparative testing platform for scientific research. At the same time, the practicality of modular assembly and the intuitive display of defect morphology, combined with the full process presentation of loading simulation and data monitoring, meet the needs of combining theory with practice in teaching and training, and achieve dual adaptation for scientific research experiments and teaching training. This results in expanding application scenarios and enhancing the comprehensive utilization value of the system.

[0017] 3. This invention significantly improves test adaptability through rapid construction and flexible reconstruction. Relying on standardized lining ring modules, the basic tunnel body can be quickly assembled. With the precise positioning and locking mechanism of the reconfigurable modules, the target functional modules can be quickly replaced to the designated position without overall reconstruction or large-area demolition. It can flexibly switch between various working conditions such as cracks, cavities, and new material testing. At the same time, the modular design allows the system to simulate various structural and defect combinations in a limited space. It not only solves the problem of poor site adaptability of traditional models, but also meets the needs of combining theory with practice in teaching and training through assembly operability and intuitive demonstration of defects.

[0018] 4. This invention significantly reduces testing costs by combining economic efficiency and data reliability. Core components such as standardized lining rings, loading and monitoring modules are reusable, requiring only the replacement of small-sized functional modules. This avoids the waste of repeated construction of traditional cast-in-place models, greatly saving material and time costs and shortening the testing cycle by more than 60%. The factory prefabrication process ensures the consistency of functional module parameters. Combined with high-precision sensing monitoring and multi-channel data acquisition modules, it effectively improves the comparability and scientific validity of test data. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the system flow in an embodiment of the present invention; Figure 2 This is a schematic diagram of the method steps in an embodiment of the present invention. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0021] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Please see the appendix Figure 1 -Appendix Figure 2 This invention discloses a pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components. The pilot-scale simulation system includes the following modules: Basic support module: Provides a stable bearing foundation and standard connection interface, which fixes the standardized lining ring module and the pre-set working condition function module to itself, ensuring the overall structural stability of the system; Standardized lining ring module: It is composed of multiple arc-shaped standard lining blocks to form a complete tunnel ring. According to the tunnel structure layers, it is divided into an initial support simulation ring, a waterproof layer simulation ring, and a secondary lining simulation ring to simulate the structural morphology and force transmission path of a healthy section of the tunnel. Pre-set working condition function module: It is made in the factory with the same external geometry and connection interface as the standardized lining block. It can directly replace the corresponding standard block in the standardized lining ring module to simulate working conditions such as tunnel cracks, voids, leakage and material variation, and has plug-and-play characteristics. Loading simulation module: Simulates external load environments such as tunnel surrounding rock stress and water pressure, and adjusts the loading force and loading range according to the instructions of the system control module to match the actual engineering load scenario; Sensing and monitoring module: Collects strain, displacement and seepage pressure response data of the simulated main structure through built-in sensors. The simulated main structure is the overall structure assembled from the standardized lining ring module and the pre-set working condition function module, providing raw data support for experimental analysis. Data acquisition module: Receives data transmitted from the sensor monitoring module, performs preliminary processing such as filtering and format conversion to ensure data integrity and validity; System control module: As the core of system control, it receives processed data from the data acquisition module, combines it with the preset parameters of the test plan, and generates loading control commands and module reconfiguration commands to realize automated control of the test process; Reconfiguration and adaptation module: Receives reconfiguration instructions from the system control module, and based on precise positioning and locking mechanisms, enables the rapid disassembly, replacement, and assembly of standardized lining blocks and pre-set working condition functional modules, ensuring the structural accuracy and connection firmness after module replacement. Example

[0023] Test on the impact of cracks on the mechanical properties of tunnel structures The following are the specific steps for conducting experiments on the impact of crack defects on the mechanical properties of tunnel secondary lining structures: Test preparation: The test condition was determined to be the structural mechanical response of the tunnel arch with circumferential cracks under Class III surrounding rock conditions. Standardized lining ring modules (secondary lining simulated ring reinforcement spacing 120mm, reinforcement diameter 14mm) and crack modules (prefabricated initial width) were selected. The system consists of a circumferential crack (mm), a foundation support module, a loading simulation module, a sensing and monitoring module, a data acquisition module, a system control module, and a reconfiguration and adaptation module. The integrity of the connection interfaces of each module is checked.

[0024] System assembly: Installation of foundation support module: The bearing foundation is made of C30 reinforced concrete with a thickness of 500mm. It is equipped with a double layer of Φ16 steel mesh with a spacing of 180mm. The spacing of the embedded steel plate is staggered from the splicing position of the standard lining block. Assemble standardized lining rings: Assemble them in the order of initial support simulation ring, waterproof layer simulation ring, and secondary lining simulation ring, using high-strength bolts to ensure tight fit of the connection surfaces; Replace the crack module: Remove the standard lining block at the simulated ring arch position of the secondary lining, and position it by reconstructing the tapered positioning pin of the adapter module (taper 1:80). Align the crack module with the surrounding standard blocks, and tighten it with an electric bolt tightener (tightening torque 300 N·m). The position detection sensor confirmed that the coaxiality error was 0.3 mm, which meets the requirements.

[0025] Parameter settings: The test parameters are set via the system control module to simulate the unit weight of the surrounding rock. =22kN / m 3 burial depth =30m, Class III surrounding rock correction factor =1.3, loading efficiency coefficient =0.95, according to the geostress calculation formula =1.3×22×30×0.95=80.55MPa, set the target load value to 80MPa, the load rate to 0.05MPa / s, and the data acquisition frequency to 50Hz; The temperature sensor collects the prefabricated ambient temperature at 20℃, and the test ambient temperature at 25℃. =5℃, select the temperature correction factor for crack width. =0.005 / ℃, according to the formula for equivalent working width of cracks =0.2×(1+0.005×5)=0.205mm.

[0026] Test execution: The loading simulation module is started, and the hydraulic loading unit applies the load at a set rate. The load distribution component evenly transmits the load through the arc-shaped pressure plate. The sensing and monitoring modules work synchronously: three strain gauges (40mm apart) are installed on the arch section, a radial displacement meter monitors the arch settlement, and a temperature sensor collects the ambient temperature in real time. The data acquisition module filters the sensor data to remove electromagnetic interference noise and stores it in CSV format, which includes information such as timestamp, sensor number, and measurement value.

[0027] Data processing and analysis: The system control module displays the strain and displacement data change curves in real time. When the load reaches 80MPa, the maximum strain value of the arch is 180με and the maximum settlement displacement is 3.2mm. The data is stable without sudden changes. Loading is stopped and all test data are saved.

[0028] System Reconfiguration: By reconfiguring the adapter module to disassemble the crack module and replace it with a new standard lining block, comparative tests of cracks with different widths or locations can be carried out. The module disassembly and reassembly time does not exceed 2 hours, which greatly improves the test efficiency. Example

[0029] Tunnel lining void defect leakage test The system conducts experiments to test the impact of voids and defects behind the tunnel lining on leakage performance. The specific steps are as follows: Test preparation: Select standardized lining ring modules and back defect modules (preset void cross-sectional area). =0.1m 2 axial length =1.2m), leakage module, loading simulation module, sensing and monitoring module, etc. The defect module has an inflatable airbag embedded in the back, and the leakage module integrates a micro water pipe system.

[0030] System assembly: After the basic support module is installed, the standardized lining ring healthy section is assembled, and the defect module installation area is reserved at the side wall position; Install the defective module behind the installation: Adjust the airbag inflation volume to fill the voids. =0.8, according to the formula for equivalent volume of voids =0.1×1.2×0.8=0.096m 3 Simulate partial void working conditions and complete positioning and locking by reconstructing the adaptation module; Leakage modules are installed at adjacent locations, and piezometers are placed at the inlet and outlet of the leakage channel to ensure measurement accuracy.

[0031] Parameter settings: Simulate Class IV surrounding rock conditions. =24kN / m 3 burial depth =40m, =1.6, =0.93, the calculated simulated geostress =1.6×24×40×0.93=142.848MPa, set loading rate 0.03MPa / s, target load 140MPa, leakage module set water pressure 0.5MPa, data acquisition frequency 80Hz.

[0032] Test execution: The simulation module applies ground stress to the target value and maintains stability. The leakage module micro water pipe system is activated, and a water pressure of 0.5 MPa is applied. The piezometer collects the inlet and outlet water pressure difference in real time, the displacement gauge monitors the displacement change of the sidewall, and the data acquisition module continuously stores the test data.

[0033] Results Analysis: The test lasted for 3 hours. The piezometer monitored a stable inlet and outlet water pressure difference of 0.02 MPa, indicating that the void defect caused a slight increase in leakage. The maximum displacement of the sidewall was 2.8 mm, and no abnormal deformation occurred in the structure. The test data are valid and can be adjusted. Value (e.g.) =0.5、 =1.0) Conduct comparative experiments on different cavity sizes. Example

[0034] Performance testing of new lining materials The mechanical properties of the novel fiber-reinforced concrete lining material were systematically tested. The specific steps are as follows: Experimental preparation: Select standardized lining ring module, material testing module (made entirely of new fiber concrete, with dimensions consistent with standard lining blocks), loading simulation module, sensing and monitoring module, etc. The material testing module has reserved sensor installation holes.

[0035] System assembly: Assemble the standardized lining ring reference section, replace the material test module at the arch waist position, ensure installation accuracy by reconstructing the positioning guide mechanism of the adapter module, and check the flatness of the connection surface after locking and fixing. Strain gauges were attached to the inner and outer surfaces of the material testing module. Four strain gauges (spaced 35 mm apart) were placed on the arch waist section, and displacement gauges were evenly distributed radially and axially.

[0036] Parameter settings: Simulate Class II surrounding rock conditions. =20kN / m 3 burial depth =25m, =1.1, =0.97, the calculated simulated geostress =1.1×20×25×0.97=53.35MPa, set the graded loading mode, each stage loads 5MPa, stabilizes for 5 minutes and then continues loading, data acquisition frequency 60Hz.

[0037] Test execution: The load was applied according to the graded loading scheme, and strain and displacement data were recorded at each stage of pressure stabilization. When loaded to 60MPa, the strain value of the material testing module was 210με, the displacement value was 4.1mm, and no cracks were generated; when loaded to 80MPa, the strain value was 320με, and there were still no signs of failure, indicating that the mechanical properties of the new fiber-reinforced concrete material are superior to those of traditional concrete.

[0038] Experimental reconstruction: Disassemble the material testing module, replace it with a material testing module with different fiber content, and repeat the above test procedure. This can quickly complete multiple sets of comparative tests and provide data support for the optimization of the performance of new materials.

[0039] The above three embodiments all verify the flexibility, repeatability and reliability of the test data of the system of the present invention. Compared with the traditional cast-in-place model, the test cycle is shortened by more than 60%, the test cost is reduced by 50%, and it can meet the test requirements of different working conditions and different materials, which has significant technical advantages and practical value.

[0040] Specifically, the pre-set working condition function module adopts a modular integrated design. The connection interface of each defect sub-module is fully compatible with the standardized lining block. When replacing, there is no need to modify the overall structure of the lining ring. The module has reserved sensor installation channels, and corresponding monitoring elements can be built in according to test requirements to directly collect local structural response data of the defect area. Different defect sub-modules can be used in combination. For example, the crack module and the leakage module can be superimposed to simulate the crack and leakage coupled working condition. The module surface is treated with anti-corrosion and wear-resistant treatment to adapt to multiple disassembly and assembly test scenarios, ensuring the consistency and durability of defect simulation.

[0041] Specifically, the positioning and guiding mechanism and the locking and fixing mechanism of the reconstructed adapter module work together. During the positioning stage, the interface is quickly aligned by a conical positioning pin, reducing manual calibration time. During the locking stage, the electric bolt tightener locks the module in stages according to the preset torque to avoid local stress concentration. The position detection sensor provides real-time feedback on the module's installation posture. If a deviation exceeds the allowable range, the system automatically triggers a reset command. The locking operation is then performed after the deviation is corrected. This module is compatible with different types of standardized lining blocks and defective modules. The disassembly and assembly process does not require special heavy equipment, balancing ease of operation and structural connection reliability.

[0042] Specifically, the system control module has built-in multiple preset test scenario templates, supports user-defined loading logic and data judgment rules, and the control software has real-time data analysis capabilities. It can predict the trend of the collected structural response data and automatically adjust the loading rate or issue an early warning signal when the data approaches the preset threshold. The signal output interface adopts an anti-interference design to ensure stable transmission of control commands in complex test environments. At the same time, the module supports linkage with external data processing systems, which can synchronize test data to cloud storage in real time, facilitating multi-terminal viewing and test process traceability, and improving test management efficiency.

[0043] Working principle: First, the foundation support module provides a stable bearing foundation and standard connection interface for the entire system through a reinforced concrete foundation and precisely positioned pre-embedded connection components. This ensures the firm fixation of the standardized lining ring module and the pre-set working condition function module, guaranteeing the overall structural stability. Then, the initial support simulation ring, waterproof layer simulation ring, and secondary lining simulation ring are assembled according to the tunnel structural layers to form a complete standardized lining ring. Next, the corresponding standard blocks are replaced by plug-and-play pre-set working condition function modules to accurately simulate specific defects such as tunnel cracks and voids. Finally, the system control module sends commands to the loading simulation module according to the preset parameters of the test plan. The hydraulic loading unit, combined with the load distribution component, simulates the surrounding rock stress and water pressure. Under external loads, the sensing and monitoring module collects structural strain, displacement, and seepage pressure response data through various high-precision sensors. The data acquisition module then performs preliminary processing such as filtering and format conversion on the sensor data to ensure its validity before transmitting it to the system control module. The system control module analyzes and processes the data in real time, dynamically adjusting the loading commands. If the data exceeds a preset threshold, an alarm is automatically triggered and loading stops. Finally, according to the test requirements, the reconfiguration and adaptation module, based on the reconfiguration commands from the system control module, uses a positioning and guiding mechanism, a locking and fixing mechanism, and position detection sensors to quickly disassemble, replace, and precisely assemble standardized lining blocks with preset working condition functional modules, completing multi-working-condition simulation switching. This concludes the entire workflow.

[0044] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components, characterized in that, The pilot-scale simulation system includes the following modules: Basic support module: Provides a stable bearing foundation and standard connection interface to fix the standardized lining ring module and the pre-set working condition function module to itself; Standardized lining ring module: It is composed of multiple arc-shaped standard lining blocks to form a complete tunnel ring. According to the tunnel structure layers, it is divided into an initial support simulation ring, a waterproof layer simulation ring, and a secondary lining simulation ring to simulate the structural morphology and force transmission path of a healthy section of the tunnel. In the standardized lining ring module, the initial support simulation ring is formed by alternating splicing of precast concrete blocks and precast steel arch units using high-strength mechanical connectors. The cross-sectional shape of the precast steel arch units is either I-shaped or H-shaped, with a spacing of 500-800mm. The waterproof layer simulation ring is a frame-type openable structure made of aluminum alloy, with an opening angle range of 0-180°. The geotextile laid inside has a basis weight of 300-400g / m². 2 The thickness of the waterproof membrane is 1.5-2.0mm, and the waterproof membrane is fixed to the frame by pressure strips. The secondary lining simulation ring is made of precast reinforced concrete blocks. The precast blocks are equipped with double-layer bidirectional steel bars with a spacing of 100-150mm and a diameter of 12-16mm. Pre-set working condition function module: It is made in the factory with the same external geometry and connection interface as the standardized lining block. It directly replaces the corresponding standard block in the standardized lining ring module to simulate working conditions such as tunnel cracks, voids, leakage and material variation. The pre-set working condition function module includes at least two combinations of the following: crack module, concrete defect module, underlying defect module, leakage module, material testing module, and strength variation module. The equivalent working width of the crack in the crack module is calculated based on the following formula: ； in, The equivalent working width of the crack is the actual effective width of the crack during the test. The initial width of the crack during factory prefabrication. The temperature correction factor for crack width is determined based on the difference between the test environment temperature and the prefabrication environment temperature. This is the difference between the test environment temperature and the pre-fabricated environment temperature; The equivalent volume of the void in the underlying defect module is calculated based on the following formula: ； in, The equivalent volume of the void is used to simulate the actual effective void volume behind the lining. The cross-sectional area of ​​the pre-set cavity on the back of the module is a fixed value, formed by prefabrication from a mold. The axial length of the pre-set working condition function module is completely consistent with the axial length of the standardized lining block. This is the void filling coefficient, with a value range of 0 ≤ ≤1, based on the control of the inflation volume of the inflatable airbag pre-embedded in the back of the defect module and the filling volume of the removable filler, when It was in a completely hollow state at the time. At time 0, there are no voids. Loading simulation module: Simulates external load environments such as tunnel surrounding rock stress and water pressure, and adjusts the loading force and loading range according to the instructions of the system control module to match the actual engineering load scenario; Sensing and monitoring module: Collects strain, displacement and seepage pressure response data of the simulated main structure through built-in sensors. The simulated main structure is the overall structure assembled from the standardized lining ring module and the pre-set working condition function module. Data acquisition module: Receives data transmitted from the sensor monitoring module and performs preliminary processing such as filtering and format conversion; System control module: Receives processed data from the data acquisition module, combines it with preset parameters of the test plan, and generates loading control commands and module reconfiguration commands; Reconfiguration and adaptation module: Receives reconfiguration instructions from the system control module, and enables the rapid disassembly, replacement, and assembly of standardized lining blocks and preset working condition functional modules based on precise positioning and locking mechanisms; The reconfiguration and adaptation module includes a positioning guide mechanism, a locking and fixing mechanism, and a position detection sensor. The positioning guide mechanism adopts a structure in which a tapered positioning pin and a positioning hole are matched. The taper of the positioning pin is 1:50-100. The locking and fixing mechanism uses an electric bolt tightener. The tightening torque can be continuously adjusted within the range of 50-500 N·m. During the tightening process, the torque value is monitored in real time. When the torque reaches the preset value, the tightening automatically stops and a locking completion signal is fed back. The position detection sensor uses a laser displacement sensor to monitor the position deviation during the module replacement process in real time. When the deviation exceeds the allowable range, an alarm signal is issued to prevent the locking operation.

2. The pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components according to claim 1, characterized in that: The basic support module includes a bearing foundation and pre-embedded connection components. The pre-embedded connection components are one or more combinations of pre-embedded steel plates, bolt hole groups, or socket structures. The layout positions of the pre-embedded connection components correspond one-to-one with the connection interfaces of the standardized lining ring module and the pre-set working condition function module. The layout spacing is staggered from the splicing joint positions of the standard lining blocks. The bearing foundation is formed by casting reinforced concrete with a casting thickness of not less than 500mm. A double-layer steel mesh is set inside the foundation with a steel mesh spacing of 150-200mm and a steel bar diameter of not less than 16mm.

3. The pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components according to claim 2, characterized in that: The loading simulation module includes a hydraulic loading unit, a load distribution component, and a pressure feedback sensor. The simulated ground stress value is calculated based on the following formula: ； in, To simulate the ground stress value, that is, the equivalent surrounding rock stress applied to the simulated main structure, This is a correction factor for the surrounding rock level, determined based on the simulated surrounding rock level, for Class I surrounding rock. Class II surrounding rock Class III surrounding rock Class IV surrounding rock Class V surrounding rock , To simulate the unit weight of the surrounding rock, the value was selected based on the actual rock type of the tunnel project, ranging from 18 to 26 kN / m. 3 , To simulate the tunnel's burial depth, the values ​​were determined based on the simulated working conditions set in the test plan, with a range of 5-100m. The loading efficiency coefficient, considering the mechanical efficiency and load transfer loss of the hydraulic loading unit, is taken in the range of 0.9-1.

0. The hydraulic loading unit adopts a servo hydraulic control system, and the loading rate is continuously adjustable in the range of 0.01-0.1MPa / s, with a pressure control accuracy of ±0.01MPa. The load distribution component adopts a distributed arc-shaped pressure plate structure, and the curvature of the pressure plate is completely in contact with the outer arc surface of the simulated main structure, with a contact gap of no more than 0.5mm. The pressure plate is made of Q355 steel with a thickness of 20-30mm.

4. The pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components according to claim 3, characterized in that: The sensing and monitoring module includes strain gauges, displacement gauges, piezometers, and temperature sensors. The measurement accuracy of all sensors is no less than 0.1%. The strain gauges are foil strain gauges, which are attached to the inner and outer surfaces of the standardized lining blocks and the pre-set working condition functional modules. At least three strain gauges are installed at each key section of the arch crown, arch waist, sidewalls, and arch bottom. The displacement gauges are drawn wire displacement sensors, which are installed in the axial and radial directions of the tunnel simulation main structure. One sensor is installed every 2m in the axial direction, and one sensor is installed at each key section of the arch crown, arch waist, and sidewalls in the radial direction. The piezometers are vibrating wire piezometers, which are only installed at the inlet and outlet positions of the preset leakage channels of the leakage module. The temperature sensors are platinum resistance temperature sensors, which are installed around the simulation main structure and inside the pre-set working condition functional modules.

5. The pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components according to claim 4, characterized in that: The data acquisition module includes a data acquisition card, a signal amplifier, and a data buffer unit. The signal amplifier is a programmable gain amplifier that amplifies the weak electrical signal output by the sensing and monitoring module to a range that the data acquisition card can recognize, while suppressing environmental electromagnetic interference. The data acquisition card is a multi-channel synchronous acquisition card with no fewer than 32 channels. The data buffer unit uses a solid-state drive with a storage capacity of no less than 100GB. Each data file contains a data acquisition timestamp, sensor number, measured value, and data checksum information.

6. The pilot-scale simulation system for reconfigurable tunnel engineering based on prefabricated components according to claim 5, characterized in that: The system control module includes an industrial control computer, control software, and a signal output interface. The industrial control computer serves as the control core and supports visual setting of test parameters. The control software has functions for setting test parameters, real-time control of the loading process, real-time data display, anomaly alarm, and data storage. Test parameter settings include loading mode, loading rate, target load value, and data acquisition frequency. When the structural response data collected by the sensing and monitoring module exceeds a preset threshold, the control software automatically triggers an alarm and simultaneously controls the loading simulation module to stop loading through the signal output interface, saving all current test data. The data transmission rate of the signal output interface is no less than 100Mbps.

7. A pilot-scale simulation method for reconfigurable tunnel engineering based on prefabricated components, applicable to the pilot-scale simulation system according to any one of claims 1-6, characterized in that, The pilot-scale simulation method includes the following steps: S1. Assemble the standardized lining ring: Using the standard connection interface provided by the basic support module of the pilot simulation system, assemble multiple arc-shaped standard lining blocks to form a complete tunnel ring, including the initial support simulation ring, the waterproof layer simulation ring, and the secondary lining simulation ring. S2. Install the pre-set working condition function module: Through the reconstruction and adaptation module of the pilot simulation system, replace the corresponding standard block in the standardized lining ring with the pre-made pre-set working condition function module in the factory to simulate tunnel cracks, voids, leakage and material variation defects. S3. Apply external load: Using the loading simulation module of the pilot-scale simulation system, simulate the external load environment of surrounding rock stress and water pressure according to the test plan, and load the assembled simulated main structure. S4. Collect structural response data: Collect strain, displacement and seepage pressure data of the simulated main structure through the sensing and monitoring module of the pilot simulation system; S5. Data processing and loading control: The data acquisition module of the pilot-scale simulation system receives and processes the acquired data, and the system control module generates loading control commands in combination with preset experimental parameters to achieve automated control of the loading process. S6. Reconstruction and Replacement Module: According to the test requirements, the standardized lining blocks and the preset working condition functional modules are quickly disassembled, replaced and reassembled through the positioning and locking mechanism of the reconstruction and adaptation module of the pilot simulation system.

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