Accelerated loading test device for shield tunnel settlement

Abstract

The utility model provides an accelerated loading test device for settlement of a shield tunnel, which comprises a model box and a model tunnel penetrating through the model box, in a test state, corresponding soil layers and sandy soil are filled outside the model tunnel in the model box, and a plurality of pressure detectors are arranged in corresponding areas below the model tunnel; a track assembly and a loading assembly are arranged in the model tunnel, and the loading assembly is arranged on the track assembly; the loading assembly comprises a counter-force longitudinal beam, a plurality of counter-force cross beams, a plurality of force transmission beams and a plurality of vibration exciters; the counterforce longitudinal beams are arranged on the two supporting columns, the counterforce cross beams are arranged below the counterforce longitudinal beams at equal intervals, the counterforce cross beams are connected with the corresponding vibration exciters, the vibration exciters act on the rail assembly through the corresponding force transmission beams, the rail assembly is further connected with a plurality of settlement monitoring meters, the vibration exciters are all connected with an external controller, the counterforce longitudinal beams are erected on the two supporting columns, and the two supporting columns are connected with the counterforce longitudinal beams. And the two supporting columns are fixed outside the model box. The device aims at simulating tunnel settlement to obtain related data.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering test equipment, in particular to an accelerated loading test device for shield tunnel settlement. Background Art

[0002] At present, during the shield construction process, due to factors such as soil loss, changes in surrounding pore water pressure and lining deformation, the original stress of the soil will be redistributed, the original soil balance will be destroyed, and the strata will deform to varying degrees. Excessive stratum deformation will cause changes in the stress state of the soil near the tunnel, causing the tunnel to deform and a certain amount of settlement on the ground. This is a great safety hazard for subway tunnels that have been in operation. Since the on-site experiment is relatively complicated to implement, it is very necessary to invent an accelerated loading test device and test method that simulates the settlement of the shield tunnel under the action of train running load. At present, the known accelerated loading test devices at home and abroad use full-scale test devices, but their implementation is costly and cumbersome; there is no comprehensive, integrated and systematic device and test method for simulating the settlement of the shield tunnel.

[0003] The existing invention patent with patent publication number CN111879536A discloses a test device for simulating the vibration of subway tunnel train operation. Although it avoids the high test cost and over-simplification of the problem caused by the single field test to a certain extent, it can more realistically simulate the dynamic response of the tunnel structure and surrounding strata caused by train operation under different tunnel burial depths and different stratum moisture contents, but it cannot simulate the relevant data under the conditions of shield tunnel settlement. Therefore, a test device for shield tunnel settlement is urgently needed to cope with the impact of actual settlement on the tunnel. Utility Model Content

[0004] The main purpose of the utility model is to propose an accelerated loading test device for shield tunnel settlement, aiming to solve the problem that the existing test device cannot effectively simulate the shield tunnel settlement conditions and obtain relevant data.

[0005] To achieve the above-mentioned object, the utility model provides an accelerated loading test device for shield tunnel settlement, the device comprising a model box and a model tunnel passing through the model box;

[0006] Under the test state, the model box and the model tunnel are filled with corresponding soil layers and sand, and a plurality of pressure detectors are arranged in the corresponding areas below the model tunnel;

[0007] A track assembly and a loading assembly are arranged in the model tunnel, and the loading assembly is placed on the track assembly;

[0008] The loading assembly includes a reaction longitudinal beam, a plurality of reaction cross beams, a plurality of force transmission beams and a plurality of vibration exciters;

[0009] A plurality of reaction beams are arranged at equal intervals below the reaction beams, each reaction beam is connected to a corresponding vibration exciter, each vibration exciter acts on the track assembly through a corresponding force transmission beam, the track assembly is also connected to a plurality of settlement monitoring meters, each vibration exciter is connected to an external controller, and the controller is used to control each vibration exciter to oscillate in a waveform;

[0010] The reaction longitudinal beam is mounted on two supporting columns, and both supporting columns are fixed outside the model box.

[0011] Optionally, the track assembly comprises two parallel tracks, a ballast bed, a plurality of sleepers and a plurality of fasteners;

[0012] Each track is fixed to the corresponding sleeper by multiple fasteners. The sleepers are arranged on the roadbed at equal intervals. Each settlement monitoring meter is arranged under the corresponding sleeper. Each force transmission beam is erected on two parallel tracks at equal intervals.

[0013] Optionally, the support columns are all retractable hydraulic columns.

[0014] Optionally, the model box has movable doors on both sides along the length direction of the model tunnel, and the movable doors are used for the reaction longitudinal beam to pass through.

[0015] Optionally, the inner wall of the model box has a layer of epoxy resin

[0016] Optionally, the model tunnel is formed by splicing a plurality of pipe segments.

[0017] Optionally, a rubber pad is provided between each track and the corresponding sleeper.

[0018] Optionally, a plurality of reaction beams are arranged below the reaction beams through connecting plates.

[0019] Optionally, each vibration exciter is centrally arranged on the force transmission beam.

[0020] Optionally, the two support columns are fixed outside the model box through corresponding support column bases.

[0021] Beneficial effects:

[0022] The utility model is used for the accelerated loading test device for shield tunnel settlement. By simulating the loading components, monitoring and track components, the load on the simulated track components is consistent with that on the real train, and then the real subway train can be replaced to simulate the operation process of the subway train. The exciter is used to control the waveform through the controller, and the real-time regulation is performed through the PC end to achieve effective regulation of the operation loading. The real-time automatic detection of the pressure detector and the settlement monitoring meter can be used to synchronously record the numerical changes of the settlement and soil pressure with the change of loading. Then, the performance of the tunnel under the simulated operation load is verified and analyzed, and a test plan is provided for the monitoring of the settlement of the subsequent subway project. In addition, a variety of tests can be simulated, such as the settlement influence analysis test of the tunnel segment during subway operation, the subway tunnel settlement repair test, and the effect verification test after the grouting repair of the subway tunnel settlement, etc., which has a broad application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0024] Figure 1 It is a structural schematic diagram of an embodiment of an accelerated loading test device for shield tunnel settlement according to the utility model;

[0025] Figure 2 for Figure 1 Schematic diagram of the external structure of the model box under test;

[0026] Figure 3 for Figure 1 Schematic diagram of the internal connection structure of the model box under the test state;

[0027] Figure 4 for Figure 2 Side view of

[0028] Figure 5 for Figure 1 A schematic diagram of the structure of the track component and the loading component;

[0029] Figure 6 for Figure 5 A schematic diagram of the structure of a single exciter connection;

[0030] Figure 7 for Figure 5 Schematic diagram of the structure of the track assembly.

[0031] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

[0032] Description of Figure Numbers:

[0033]

[0034] DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0039] like Figure 1-7 As shown, the utility model provides an embodiment of an accelerated loading test device for shield tunnel settlement, the device comprises a model box 1 and a model tunnel 3 passing through the model box 1, wherein the main body of the model box 1 is made of steel material, the specific size can be determined according to the required model size, and the model tunnel 3 is spliced ​​by multiple segment bolts. Preferably, the model tunnel adopts a 1:6 scaled track that is the same as the real track structure.

[0040] In the test state, the model box 1 is filled with corresponding soil layers and sand 2 outside the model tunnel 3, and a plurality of pressure detectors 6 are arranged in the corresponding areas below the model tunnel 3, such as Figure 4 As shown, the pressure detector 6 is used to detect the pressure change under the test state. Generally, the pressure detector 6 is located at a height of 0.5 m below the model tunnel 3.

[0041] Furthermore, if Figure 5-7 As shown, a track assembly and a loading assembly are provided in the model tunnel 3, and the loading assembly is placed on the track assembly. The loading assembly includes a reaction longitudinal beam 14, a plurality of reaction cross beams 9, a plurality of force transmission beams 15 and a plurality of exciters 5; wherein, a plurality of reaction cross beams 9 are arranged at equal intervals below the reaction longitudinal beam 14, preferably, a plurality of reaction cross beams 9 are vertically connected to the reaction longitudinal beam 14, and are fixed by bolt connection, and the reaction longitudinal beam 14 is mounted on two support columns 7, and the two support columns 7 are fixed outside the model box 1, so that the reaction longitudinal beam 14 and the plurality of reaction cross beams 9 provide a reaction support effect.

[0042] At the same time, each reaction beam 9 is connected to the corresponding vibration exciter 5, and each vibration exciter 5 acts on the track assembly through the corresponding force transmission beam 15. A plurality of settlement monitoring meters 10 are also connected to the track assembly. Each vibration exciter 5 is connected to an external controller, and the controller is used to control each vibration exciter 5 to oscillate in a waveform. Preferably, the vibration exciter 5 vibrates back and forth in the vertical direction, so as to simulate the actual changes in the impact of the running train on the track under normal use, and perform real-time control through the PC, so as to obtain the settlement data under the simulated state through a plurality of settlement monitoring meters 10.

[0043] Furthermore, if Figure 6 As shown, a plurality of reaction beams 9 are arranged below the reaction longitudinal beams 14 through a connecting plate 16. The connecting plate 16 and the reaction beams 9 and the reaction longitudinal beams 14 are all connected and fixed by bolts.

[0044] Furthermore, if Figure 2-3 As shown, two support columns 7 are fixed to the outside of the model box 1 through corresponding support column bases 8. Specifically, the support columns 7 are fixed to the corresponding test site by bolts through the bases 8. Preferably, the support columns 7 are all retractable hydraulic columns, so that the height adjustment of the loading assembly can be achieved.

[0045] Furthermore, if Figure 5 , 7As shown, the track assembly includes two parallel tracks 4, a ballast 13, a plurality of sleepers 12 and a plurality of fasteners 11, wherein each parallel track 4 is fixed to the corresponding sleeper 12 by a plurality of fasteners 11, each sleeper 12 is arranged on the ballast 13 at equal intervals, the ballast 13 is made of precast concrete material or crushed stone and other materials, and the sleepers 12 can be made of concrete, wood and other materials according to the situation; each settlement monitoring meter 10 is arranged under the corresponding sleeper 12, thereby realizing synchronous recording of the settlement data of the track assembly; preferably, a rubber pad is also arranged between each track 4 and the corresponding sleeper 12, which has a certain buffering effect. Preferably, the force transmission beam is made of steel with a size of 0.04m×0.03, and the parallel track 4 is made of high-strength steel.

[0046] Furthermore, each force transmission beam 15 is equally spaced on two parallel tracks 4, and each exciter 5 is centrally arranged on the corresponding force transmission beam 15, so that the load of the exciter 5 acts on the force transmission beam 15 and is transmitted to the parallel tracks through the force transmission beam 15, so as to improve the accuracy of the simulation data. Under the test state, the maximum excitation force of the exciter 5 reaches the design axle weight of the simulated vehicle, and the maximum excitation frequency of the exciter 5 is obtained by dividing the maximum vehicle speed by the minimum wavelength.

[0047] Among them, based on the empirical expression of the load variation of the fastener 11 over time under different train load types, the following is obtained through the empirical expression:

[0048]

[0049] Where: P0 is the wheel-rail force; x ij is the train axle position; x i is the train speed; t is the time; A is a constant, whose value is equal to the maximum proportion of the load borne by the fastener 11 under the action of a single train axle; ω is a constant, which is related to the longitudinal influence range of the single axle load. For a typical high-speed railway slab track, A = 0.34, ω = 0.76.

[0050] The movement process of the train is achieved by controlling the time difference Δt of adjacent exciters 5:

[0051]

[0052] Wherein Δs is the spacing between the fasteners 11. For a specific track, the spacing between the fasteners 11 is a fixed value. The spacing between the fasteners 11 in this test is 0.16 m.

[0053] The phase difference between adjacent exciters 5 has nothing to do with the train speed and is only determined by the spacing between the fasteners 11 and the length of the train carriage, and can be calculated from the time difference and period of adjacent exciters 5;

[0054]

[0055] Furthermore, if Figure 2 As shown, the model box 1 has movable doors on both sides along the length direction of the model tunnel 3, and the movable doors are used for the reaction longitudinal beam 14 to pass through.

[0056] Furthermore, the inner wall of the model box 1 has an epoxy resin layer, which provides a certain anti-corrosion protection effect for the model box 1 .

[0057] Furthermore, for the simulation of the moving load of the train, the control of the connected exciter 5 is a multi-channel dynamic controller, the purpose of which is to synchronously control the front and rear loading behaviors of multiple exciters 5 while ensuring the control of the waveform parameters of a single exciter 5.

[0058] In addition, in order to better illustrate the structure and testing method of the utility model, the following is explained through detailed operating steps, the details are as follows:

[0059] (1) Setting of model box and model tunnel:

[0060] The main body is made of steel material to form a preset size model. In this embodiment, the size of the simulation test model box is set to 4m×3m×3m, and the model box 1 is provided with movable doors on the front and rear sides, and a model tunnel with a diameter of 1m is made of pipe segments in the model box.

[0061] (2) Setting of track components:

[0062] The track assembly includes two parallel tracks 4, a ballast bed 13, sleepers 12 and fasteners 11; the sleepers 12 can be made of concrete, wood or other materials according to the actual situation; the ballast bed 13 can also be selected according to whether it is a ballasted track or a ballast track.

[0063] (3) Installation and setting of model tunnel:

[0064] A 0.5m thick soil layer is filled in the model box 1 and compacted, and then the soil is filled and compacted again to make the soil layer 0.5m thick. A plurality of pressure detectors are set on the 0.5m thick compacted soil layer, and a pressure detector 6 is set every 0.5m. Sand is filled and compacted again to make the soil layer 1m thick, and then the model tunnel 3 with a diameter of 1m is placed on the soil layer.

[0065] (4) Installation and setting of track components and loading components:

[0066] A ballast bed is laid inside the model tunnel 3, and a sleeper 12 is set every 0.08m on the ballast bed 13, and then a parallel track 4 is laid on the sleeper 12, and the parallel track 4 is connected to the sleeper 12 with a fastener 11. The width of the parallel track 4 is 0.24m, the sleeper 12 is made of 0.04m×0.03m concrete, and the parallel track 4 is made of high-strength steel. A settlement detector 10 is set under the sleeper 12 on the ballast bed. The parallel track 4 is fixed to the sleeper 12 by the fastener 11 system. An acceleration loading device is arranged on the parallel track 4, and the loading assembly consists of a connecting plate, a reaction beam 9, a reaction beam 14, an exciter 5 and a force transmission beam 15. Force transmission beams 15 are set at equal intervals on the parallel track 4, and are all set on the sleepers 12. The exciter 5 is placed on the force transmission beam 15, and the exciter 5 is pressed in the middle of the force transmission beam 15. The exciter 5 is fixed to the reaction beam 9 through a bolt connection plate, and the reaction beam 9 is fixed to the reaction longitudinal beam 14 through a connection plate 16. The reaction longitudinal beam 14 passes through the movable door of the model box 1 and is connected to the support column 7 through a double row of 4 bolts. The support column is fixed to the test site through a base 8 with 4 bolts. The exciter 5 is connected to an external controller.

[0067] (5) Simulation train operation load setting:

[0068] The external controller is responsible for the control of the exciter 5, sensor data collection, test status monitoring and protection, and realizes effective control of the loading waveform, load / displacement amplitude, excitation frequency and phase. The controller can feedback and adjust the input load or displacement in real time through the force and displacement sensors built into the exciter 5, so as to realize accurate control of the system excitation load or displacement. A variety of loading waveforms are pre-set inside the controller, such as sine waves, half-sine waves, triangle waves and rectangular waves; in order to meet the needs of users, a custom waveform input channel is reserved. For example, the "M" type wave borne by the fastener 11 system under the train load is achieved by writing the waveform formula into the system excitation waveform through a custom waveform, thereby realizing the simulation of the train load. For the simulation of the moving load of the train, the controller needs to adopt a multi-channel dynamic controller, which can not only ensure the control of the waveform parameters of a single exciter 5, but also synchronously control the front and rear loading behaviors of multiple exciters 5.

[0069] Therefore, the parallel track 4 model is loaded step by step through the loading assembly, and the lower soil layer is compressed, causing the subway tunnel to settle. The change in settlement with the loading is recorded, and the performance of the subway tunnel under the simulated train running load is verified and analyzed. Furthermore, this experiment provides an accelerated loading test device and test method for shield tunnel settlement under simulated train running load, providing a test plan for monitoring the settlement of actual subway projects.

[0070] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or system including the element. The serial numbers of the above-mentioned embodiments of the utility model are for description only and do not represent the advantages and disadvantages of the embodiments.

[0071] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An accelerated loading test device for shield tunnel settlement, characterized in that: The device comprises a model box (1) and a model tunnel (3) passing through the model box (1); In a test state, the model box (1) is filled with corresponding soil layers and sand (2) outside the model tunnel (3), and a plurality of pressure detectors (6) are provided in corresponding areas below the model tunnel (3); A track component and a loading component are arranged in the model tunnel (3), and the loading component is placed on the track component; The loading assembly comprises a reaction force longitudinal beam (14), a plurality of reaction force cross beams (9), a plurality of force transmission beams (15) and a plurality of vibration exciters (5); A plurality of reaction beams (9) are arranged at equal intervals below the reaction beam (14), each reaction beam (9) is connected to a corresponding vibration exciter (5), each vibration exciter (5) acts on the track assembly through a corresponding force transmission beam (15), the track assembly is also connected to a plurality of settlement monitoring meters (10), each vibration exciter (5) is connected to an external controller, and the controller is used to control each vibration exciter (5) to oscillate in a waveform; The reaction longitudinal beam (14) is mounted on two support columns (7), and the two support columns (7) are both fixed outside the model box (1).

2. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The track assembly comprises two parallel tracks (4), a ballast (13), a plurality of sleepers (12) and a plurality of fasteners (11); Each track (4) is fixed to a corresponding sleeper (12) via a plurality of fasteners (11), each sleeper (12) is arranged at equal intervals on a ballast (13), each settlement monitoring meter (10) is arranged below the corresponding sleeper (12), and each force transmission beam (15) is erected at equal intervals on two parallel tracks (4).

3. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The support columns (7) are all telescopic hydraulic columns.

4. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The model box (1) has movable doors on both sides along the length direction of the model tunnel (3), and the movable doors are used for the reaction longitudinal beam (14) to pass through.

5. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The inner wall of the model box (1) has an epoxy resin layer.

6. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The model tunnel (3) is formed by splicing a plurality of pipe segments.

7. The accelerated loading test device for shield tunnel settlement according to claim 2, characterized in that: A rubber pad is also provided between each track (4) and the corresponding sleeper (12).

8. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: A plurality of reaction force cross beams (9) are arranged below the reaction force longitudinal beam (14) via a connecting plate (16).

9. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: Each vibration exciter (5) is centrally arranged on the force transmission beam (15).

10. The accelerated loading test device for shield tunnel settlement according to claim 1, characterized in that: The two support columns (7) are fixed outside the model box (1) via corresponding support column bases (8).

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