Indoor simulation device for pipeline deformation under active instability of self-balancing shield excavation face
By employing a self-balancing structure and precise data monitoring methods, the complexity of installation and data error issues of the small-sized shield tunnel excavation face instability model test device were resolved, achieving efficient and accurate simulation of shield tunnel excavation face instability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-19
- Publication Date
- 2026-03-31
AI Technical Summary
Existing small-sized shield tunnel excavation face instability model test devices suffer from problems such as complicated installation of drive equipment, high cost, large data measurement errors, and severe influence of friction, resulting in inaccurate test results.
It adopts a self-balancing structure, uses a reaction frame to provide reaction force, and precisely controls the piston movement through a dial indicator and a thin-film pressure sensor. Combined with transparent acrylic glass material, it reduces friction, and the monitoring module records data in real time.
The structure of the test device was simplified, the installation difficulty and cost were reduced, the data accuracy and test efficiency were improved, and the accurate simulation of the instability process of the excavation face was achieved.
Smart Images
Figure CN224066527U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of shield tunnel model testing technology, specifically relating to an indoor simulation device for pipeline deformation under active instability of the self-balancing shield excavation face. Background Technology
[0002] During tunnel boring machine (TBM) excavation, the internal pressure of a soil chamber or slurry chamber is used to balance the soil pressure in front of the excavation face, maintaining its stability. If the pressure inside the chamber is too low, it can lead to active instability of the excavation face, causing soil collapse and surface subsidence. Conversely, if the pressure is too high, it can lead to passive instability, causing soil to erupt and the surface to heave. Once instability occurs during TBM excavation, soil displacement is inevitable, leading to deformation of existing pipelines. Excessive pipeline deformation can not only disrupt water, electricity, and telecommunications services but also threaten the safety of urban residents.
[0003] Current methods for evaluating the stability of shield tunnel excavation faces and assessing the impact of active and passive instability on pipelines are generally implemented through theoretical calculations or numerical analysis. However, neither of these methods can accurately reflect the actual conditions on-site. Traditional model testing systems for shield tunnel excavation face instability can be categorized into centrifugal model testing systems and small-scale model testing systems. Centrifugal model testing systems have high requirements for testing equipment and site conditions, and the equipment is expensive; currently, only a few research institutions possess the necessary resources. In contrast, small-scale model testing systems offer advantages such as lower equipment requirements, ease of operation, and lower cost. Furthermore, with the development of measurement technology in recent years, the testing accuracy of small-scale models has been continuously improved.
[0004] The existing model test device for pipeline deformation under instability of the excavation face of small-sized shield tunnels mainly consists of four parts: model box, tunnel model, pipeline model and power unit. The power unit consists of bracket, earth pressure box for testing the support force acting on the piston and drive equipment.
[0005] Therefore, the following defects exist: 1) The drive equipment includes a series of hardware such as a mounting base, servo motor, electric push rod and power supply, which has high requirements for test conditions, is troublesome to install, and is difficult to control in terms of cost;
[0006] 2) When the excavation face becomes unstable, the pressure of the soil acts on the piston, and then the piston, squeezed by the soil, transmits the pressure to the earth pressure cell through the drive device. Therefore, the data of the earth pressure cell is the ultimate support pressure when the excavation face becomes unstable. The pressure measured by this transmission method has a large error. Due to the gap between the piston, drive device and earth pressure cell, the test results reflected by the earth pressure cell are inaccurate.
[0007] 3) The semi-circular piston and the acrylic plate of the model box and the shield tunnel model are in close contact. When the piston moves, it will inevitably rub against the acrylic plate and the shield tunnel model. This friction seems unavoidable, but this effect will be reflected in the data of the earth pressure cell, causing the earth pressure to deviate significantly from the actual results. Utility Model Content
[0008] This invention aims to provide an indoor simulation device for pipeline deformation under active instability of the excavation face of a self-balancing shield tunnel. The device has a simple structure and is easy to install. It has small soil pressure measurement error and can accurately control the piston's running speed and running distance. It solves the problems of troublesome installation of drive equipment, excessively high test conditions, inaccurate test results of data from the soil pressure cell response to excavation face instability, and excessive friction when the piston moves, which are problems encountered when using small-size model test systems.
[0009] Therefore, the technical solution adopted by this utility model is as follows: an indoor simulation device for pipeline deformation under active instability of a self-balancing shield tunnel excavation face, comprising a test module and a monitoring module. The test module includes an open test chamber filled with standard sand, a hollow circular tube simulating tunnel lining installed on the inner side of the front of the open test chamber, a cylindrical solid glass support plate simulating the shield tunnel excavation face, a four-sided prism piston rod controlling the displacement of the excavation face, and a reaction frame. The four side plates of the test chamber are all made of transparent material. The tunnel lining is tightly fitted with the front side of the test chamber to form a cavity for horizontal movement of the shield tunnel excavation face and the piston rod. Eight threaded holes are provided on the contact surface between the tunnel lining and the front side plate of the test chamber. The piston rod... One end is tightly connected to the support plate with glass glue, and the other end has a threaded hole and contacts the reaction frame steel through a connecting screw. One side of the reaction frame is connected to the front side of the test chamber, and the other side contacts the connecting screw. The monitoring module includes strain gauges, settlement rods, thin-film pressure sensors, control circuit boards, static stress-strain testing and analysis systems, and real-time monitoring computers. The strain gauges are arranged in a full-bridge manner along the upper and lower surfaces of the pipeline. The strain gauges are connected to the static stress-strain testing and analysis system and the real-time monitoring computer through wires. The settlement rods are installed along the top of the existing pipeline and the soil surface. The thin-film pressure sensors are pasted on the front wall of the support plate and are connected to the control circuit board.
[0010] Preferably, the tunnel lining, tunnel excavation face support plate, and prism piston rod are all made of transparent organic acrylic glass. Acrylic glass is resistant to acids and alkalis, has high hardness, is impact-resistant, and is easy to maintain. Acrylic glass is usually used in instruments and meters in industry. Currently, no one uses this material to make the piston rod of the shield tunnel excavation face model. The choice of material is excellent. Using acrylic glass to make the tunnel lining, tunnel excavation face support plate, and prism piston rod facilitates observation at any time during the test. The prism piston rod made of acrylic glass can effectively reduce the friction between the piston and the shield tunnel lining. The inner wall of the tunnel lining and the outer side of the support plate are coated with lubricating oil, which not only provides lubrication but also prevents sand from seeping into the interior of the shield tunnel model.
[0011] A further preferred embodiment is that the piston rod has a threaded hole on the side near the reaction frame into which a connecting screw is screwed. The threaded hole matches the size of the connecting screw, resulting in a secure threaded connection that is easy to install and disassemble.
[0012] A further preferred embodiment is that the front side of the test chamber has eight evenly distributed circular holes through a flange, and the tunnel lining is fixed to the inside of the model box by screws, ensuring that the tunnel lining model is subjected to balanced force and is firmly fixed.
[0013] More preferably, the left end of the connecting screw is screwed into the piston rod hole for tight contact, and the right end has a hexagonal nut for fixing to the steel profile. Adjusting the rotation of the hexagonal nut column controls the active instability of the tunnel excavation face. The dial indicator is placed horizontally on the piston rod so that the end of the dial indicator rod is in contact with the surface of the reaction frame steel profile. The dial indicator is fixed to the piston rod with nano glue to ensure accurate monitoring of the piston speed.
[0014] More preferably, the reaction frame is made of overlapping steel sections, with one side fixed to the front of the test chamber by a connector, and the other side of the steel section having a small hole for the connecting screw to pass through and move freely, so as to facilitate the provision of reaction force.
[0015] The beneficial effects of this utility model are:
[0016] (1) Compared with the model test device for pipeline deformation under the instability of the small shield tunnel excavation face, which pushes the piston to move horizontally and reciprocally by driving equipment, this scheme uses a reaction frame to provide reaction force, and adjusts the rotating hexagonal nut to accurately control the piston's moving speed and moving distance by dial indicator. It has a simple structure, is easy to install, has relatively low test conditions, and is inexpensive.
[0017] (2) Compared with the model test device for pipeline deformation under the instability of the excavation face of small shield tunnel, the measurement error of pipeline settlement and earth pressure data is large. The lower end of the dial gauge is connected to the settlement measuring point on the pipeline through the long threaded aluminum alloy rod. The thin film pressure sensor is installed on the front wall of the support plate. The two instruments accurately record the pipeline settlement data and the earth pressure data acting on the piston on the support face when the piston moves horizontally during the test process to simulate the instability of the excavation face of the shield tunnel. The experimental data are true and reliable.
[0018] (3) The strain gauge measures the changes in longitudinal and transverse bending strain of the pipeline in the model box. The computer collects and organizes the voltage readings of the strain gauge through the static stress-strain test analysis system, which also makes it convenient for the experimenters to monitor the experiment in real time through the data displayed on the computer.
[0019] (4) The side panels of the test chamber, the tunnel lining, the tunnel excavation face support plate, and the four-sided prism piston rod are all made of transparent material, which makes it convenient for the experimenters to observe the soil change process with the naked eye and control the experimental process. Since there is a gap between the piston rod model and the support plate, without glass glue, the existence of this gap will make it difficult to control the instability process of the support surface, resulting in the failure of the experiment. Therefore, glass glue is added, which is a reasonable design.
[0020] In summary, it has advantages such as reducing the workload of experimental personnel, improving experimental efficiency, ensuring the authenticity and reliability of experimental data, and enabling real-time monitoring. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the test module of this utility model from the front.
[0022] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the back of the test module of this utility model;
[0023] Figure 3 This is one of the cross-sectional internal structural diagrams of the test module of this utility model;
[0024] Figure 4 This is the second cross-sectional view of the internal structure of the test module of this utility model;
[0025] Figure 5 This is one of the schematic diagrams of the overall planar structure of the test module and monitoring module of this utility model;
[0026] Figure 6 This is the second schematic diagram of the planar structure of the test module of this utility model.
[0027] The attached diagram lists the components represented by each number as follows:
[0028] 1. Test module; 11. Test chamber; 12. Tunnel lining; 13. Support plate; 14. Piston rod; 15. Reaction frame; 16. Pipeline; 17. Hex nut; 18. Screw; 2. Monitoring module; 21. Strain gauge; 22. Settlement rod; 23. Dial gauge; 24. Membrane pressure sensor; 25. Control circuit board; 26. Static stress-strain testing and analysis system; 27. Real-time monitoring computer. Detailed Implementation
[0029] The present invention will be further described below with reference to the embodiments and accompanying drawings:
[0030] Combination Figures 1-6 As shown, a test device for pipeline deformation under active instability of a self-balancing shield tunnel excavation face consists of test module 1 and monitoring module 2.
[0031] The test module 1 includes an open test chamber 11 filled with standard sand, a circular tunnel lining 12 installed on the inner side of the front of the open test chamber, a cylindrical solid glass support plate 13 simulating the excavation face of a shield tunnel, a square prism piston rod 14 for controlling the displacement of the excavation face, a reaction frame 15, pipelines 16, hexagonal nuts 17, and connecting screws 18. The test chamber 11 has transparent side panels. The tunnel lining 12 is tightly fitted to the front of the test chamber 11 to form a cavity for the horizontal movement of the support plate 13 and the piston rod 14. Eight threaded holes are provided on the contact surface between the tunnel lining 12 and the front side panel of the test chamber 11. One end of the piston rod 14 is tightly connected to the support plate 13 with glass glue, and the other end has a threaded hole and contacts the reaction frame 15 through the connecting screws 18. One side of the reaction frame 15 is connected to the front of the test chamber 11, and the other side contacts the connecting screws 18. The monitoring module 2 includes strain gauges 21, settlement rods 22, dial gauges 23, thin-film pressure sensors 24, control circuit boards 25, static stress-strain testing and analysis systems 26, and real-time monitoring computers 27. The strain gauges 21 are arranged in a full-bridge manner along the upper and lower surfaces of the pipeline. The strain gauges 21 are connected to the static stress-strain testing and analysis systems 26 and the real-time monitoring computers 27 via wires. The settlement rods 22 are installed along the top of the existing pipeline 16 and the soil surface. The dial gauges 23 are placed horizontally on the piston rods 14. The thin-film pressure sensors 24 are attached to the front wall of the support plate 13 and are connected to the control circuit boards 25.
[0032] Test module 1 consists of an open test chamber 11 filled with standard sand, a circular tunnel lining 12 installed on the inner side of the front of the open test chamber, a cylindrical solid glass support plate 13 simulating the shield tunnel excavation face, a quadrangular prism piston rod 14 controlling the displacement of the excavation face, a reaction frame 15, pipelines 16 and hexagonal nuts 17.
[0033] The side panels of the uncovered test chamber 11 are all made of transparent material, and the side panels of the test chamber 11 are reinforced accordingly.
[0034] The tunnel lining 12 and the tunnel excavation face support plate 13 are made of transparent organic acrylic glass material.
[0035] The shield tunnel lining 12 is tightly fitted to the front side of the test chamber 11 to form a cavity for the shield support plate 13 and piston rod 14 to move horizontally.
[0036] Lubricating oil is applied to the inner wall of the tunnel lining 12 and the outer side of the support plate 13.
[0037] Eight threaded holes are provided on the contact surface between the tunnel lining 12 and the front side plate of the test chamber 11.
[0038] The tunnel lining 12, the tunnel excavation face support plate 13, and the quadrangular prism piston rod 14 are all made of transparent organic acrylic glass, and the inner wall of the tunnel lining 12 and the outer side of the support plate 13 are coated with lubricating oil.
[0039] The piston rod 14 is preferably made of transparent organic acrylic material with a side length of 40mm.
[0040] One end of the piston rod 14 is tightly connected to the support plate 13 with glass glue.
[0041] One end of the piston rod 14 is tightly connected to the support plate 13 with glass glue, and the other end has a threaded hole that matches the size of the connecting screw 18.
[0042] The piston rod 14 has a threaded hole on the other side for mounting the connecting screw 18.
[0043] The reaction frame 15 is preferably made of aluminum alloy steel.
[0044] One end of the reaction frame 15 is fixed to the front side of the test chamber 11 by several connectors.
[0045] The left end of the connecting screw 18 is screwed into the hole of the piston rod 14, making close contact, and the right end has a hexagonal nut 17 for fixing to the reaction frame 15.
[0046] The reaction frame 15 is tightly fixed to the front side of the test chamber 11 by several connectors, and a hole is opened on the other side for the connecting screw 18 to pass through.
[0047] The other end of the reaction frame 15 has a small hole on the steel section for the connecting screw 18 to pass through and move freely. A hexagonal nut 17 is screwed into the part of the connecting screw that extends out of the steel section until it presses against the steel section, so that the connecting screw can only move by rotating the hexagonal nut 17.
[0048] The monitoring module 2 consists of strain gauge 21, settlement bar 22, dial gauge 23, thin film pressure sensor 24, control circuit board 25, static stress and strain test and analysis system 26, and real-time monitoring computer 27.
[0049] Strain gauges 21 are arranged in a full-bridge manner along the upper and lower surfaces of pipeline 16. The strain gauges 21 are connected to the static stress-strain test and analysis system 26 and the real-time monitoring computer 27 via wires. The bending moment generated by the externally applied load is converted into the voltage of the strain gauges 21. The voltage value of each group of strain gauges 21 is collected by the DHDAS dynamic signal acquisition and analysis system, and finally the bending strain of pipeline 16 is read on the static stress-strain test and analysis system 26.
[0050] Settlement rod 22 is installed along the top of the existing pipeline 16 and the soil surface.
[0051] A resistive thin-film pressure sensor 24 is attached to the front wall of the support plate 13 and connected to the control circuit board 25 via a female-to-female DuPont wire. The applied mechanical pressure is converted into an electrical signal, and the control circuit board 25 receives the electrical signal and displays the pressure value.
[0052] The dial indicator 23 is placed horizontally on the piston rod 14, and the other end is connected to the test chamber 11.
[0053] Slowly rotate the hexagonal nut and observe the advance distance and speed of the piston controlled by the dial indicator, so that the piston moves to the right at a speed of 0.002 mm / s to simulate the active destruction of the shield tunnel excavation face, and monitor various data in real time during the test.
Claims
1. An indoor simulation device for pipeline deformation under active instability of a self-balancing shield tunnel excavation face, characterized in that: The test module (1) comprises a standard sand filling test box (11) without cover, a circular tunnel lining (12) installed on the inner side of the front of the test box (11), a cylindrical solid glass support plate (13), a four-prism piston rod (14), a counterforce frame (15), and a pipeline (16). The tunnel lining (12) is tightly combined with the front side of the test box (11) to form a cavity for the horizontal movement of the support plate (13) and the piston rod (14). One end of the piston rod (14) is tightly connected with the support plate (13), and the other end is in contact with the counterforce frame (15) through a connecting screw rod (18). The monitoring module (2) comprises a strain gauge (21), a settlement rod (22), a micrometer (23), a thin film pressure sensor (24), a control circuit board (25), a static stress and strain test analysis system (26), and a real-time monitoring computer (27). The strain gauge (21) is arranged in a full-bridge manner along the circumferential side of the pipeline (16). The strain gauge (21) is electrically connected with the static stress and strain test analysis system (26) and the real-time monitoring computer (27). The settlement rod (22) is installed along the top of the existing pipeline (16) and the surface of the standard sand. The micrometer (23) is horizontally placed on the piston rod (14). The thin film pressure sensor (24) is pasted on the front wall of the support plate (13). The thin film pressure sensor (24) is electrically connected with the control circuit board (25).
2. The indoor simulation device for self-balanced shield tunneling face active instability and pipe deformation according to claim 1, characterized in that: The coverless test box (11) adopts a fully transparent acrylic plate.
3. The indoor simulation device for self-balanced shield tunneling face active instability induced deformation according to claim 1, characterized in that: The tunnel lining (12), the tunnel excavation face support plate (13), and the four-prism piston rod (14) all adopt transparent organic acrylic glass. The inner wall of the tunnel lining (12) and the outer side of the support plate (13) are coated with lubricating oil.
4. The indoor simulation device for self-balanced shield tunneling face active instability induced deformation according to claim 1, characterized in that: One end of the piston rod (14) is tightly connected with the support plate (13) by glass cement, and the other end is provided with a threaded hole. The size of the hole matches that of the connecting screw rod (18).
5. The indoor simulation device for self-balanced shield tunneling face active instability induced deformation according to claim 1, characterized in that: Eight circular threaded holes are evenly distributed on the front side of the test box (11) through a flange plate. The model tunnel lining (12) is fixed inside the test box (11) through screws.
6. The indoor simulation device for self-balanced shield tunneling face active instability and pipe deformation according to claim 4, characterized in that: The left end of the connecting screw rod (18) is screwed into the hole of the piston rod (14) until it is tightly connected. The right end is provided with a hexagonal nut (17) for fixing on the counterforce frame (15).
7. The indoor simulation device for self-balanced shield tunneling face active instability and pipe deformation according to claim 6, characterized in that: The counterforce frame (15) is tightly fixed on the front side of the test box (11) through a plurality of connecting members. The other side is provided with a hole for the connecting screw rod (18) to pass through.