Electromagnetic test device for simulating multi-displacement interaction influence of group pit supporting structure and operation method

Abstract

The invention discloses an electromagnetic test device for simulating multi-displacement interaction influence of a group pit supporting structure and an operation method. The electromagnetic test device comprises a model box, a model box shell and an array type loading system. The array type loading and unloading system is composed of first loading devices, a current loading system and an electromagnetic thrust system are arranged in each first loading device, and each electromagnetic thrust system is respectively composed of a force transmission spring, a spring displacement monitoring sensor, a water tank, a water conveying pipe, a permeable stone and a rubber mold. The test device mainly can simulate different displacement modes of a group pit supporting structure in the horizontal direction and the vertical direction, and further simulates and analyzes the influence of various foundation pit excavation lateral unloading modes on the deformation of the adjacent group pit supporting structure, and solves the problems that the lateral unloading mode of an existing group pit excavation model test is too single; and the working condition of interactive influence of subarea and block excavation of various groups of foundation pits cannot be simulated.

Description

Technical Field

[0001] The invention belongs to the field of foundation pit engineering, and in particular relates to an electromagnetic test device and an operation method for studying the multi-displacement of a group pit support structure, and analyzing the mutual influence of adjacent foundation pit excavations during the group pit excavation process. Background Art

[0002] In recent years, there are more and more underground complex projects in metropolitan areas. In the process of underground complex construction, it is inevitable to face the problem of simultaneous or cross excavation of multiple foundation pits. The excavation of adjacent foundation pits will inevitably affect the adjacent foundation pit support structure. In addition, the lateral horizontal displacement of the support structure during the foundation pit excavation process is also quite different due to different foundation pit support forms. When two or more adjacent foundation pit support structures adopt different forms, the current simulation test cannot simultaneously achieve the working conditions of simultaneous excavation of different types of foundation pits. The present invention is precisely to solve the above problems. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes an electromagnetic test device and method for simulating the multi-displacement interaction of a group pit support structure. The present invention can realize the working condition of synchronous excavation of different types of foundation pits when two or more adjacent foundation pit support structures adopt different forms.

[0004] The purpose of the present invention is to apply currents of different magnitudes and directions to the energized coil so that the electromagnetic thrust system (24) generates pulling force and thrust, thereby simulating various lateral unloading modes of foundation pit excavation, and to study the electromagnetic test device of the multi-displacement of the group pit support structure, the influence of different soil bodies on multiple foundation pit support structures, and the influence of the external environment on the multi-displacement of the group pit support structure.

[0005] This test device can mainly simulate different horizontal and vertical displacement modes of the group pit support structure, and then simulate and analyze the influence of various lateral unloading methods of foundation pit excavation on the deformation of the adjacent group pit support structure. This invention solves the problem that the lateral unloading method of the current group pit excavation model test is too single and cannot simulate the working conditions of the interactive influence of various types of group foundation pit zoning and block excavation.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] An electromagnetic test device and operation method for simulating the multi-position interaction of a group pit support structure, characterized in that it comprises a model box (1) and an array type loading and unloading system (2) located on a third shell (21);

[0008] The array loading and unloading system (2) is composed of first loading devices (3) arranged in an array, and the current loading system (23) and the electromagnetic thrust system (24) constitute the first loading device (3);

[0009] A baffle (4) is used in front of the array loading and unloading system (2) to resist the influence of the reaction force generated by the electromagnetic loading system (23) during operation on the experiment;

[0010] The current is controlled by controlling the current loading system (23) on a mobile phone or a computer, and the direction and magnitude of the current in each electromagnetic coil (7) are adjusted to make the two electromagnetic coils (7) generate a repulsive force or an attractive force, thereby pushing or pulling the inner force transmission rod (12), and the force transmission rod (12) then pushes the spring (11), and the spring (11) is compressed or stretched under the action of the pushing force or pulling force;

[0011] A laser displacement detector (8) is used to monitor the distance between the two electromagnetic coils (7), and a laser displacement detector (8) is placed at the position of the spring (11) to monitor the compression or extension distance of the spring (11);

[0012] In the current loading system (23), by changing the current magnitude, the magnitude of the pressure or tension that can be applied by the electromagnetic thrust system (24) is calculated. It is realized that the simulated force of the experiment can be obtained in the electromagnetic thrust system (24) by simply adjusting the current magnitude in the current loading system (23);

[0013] The spring (11) is connected to the water tank (19), a water pipe (13) is arranged in the spring, the water pipe (13) and the spring (11) are separated by a water pipe baffle (14), the water pipe (13) is connected to the water tank (19), and the water tank (19) is connected to the rubber module (5) by screws (15);

[0014] When the array loading and unloading system (2) is working, the influence of the force generated by the array loading and unloading system (2) on the rubber can be studied, and the rubber module (5) makes the test results more intuitive;

[0015] This test device can mainly simulate different horizontal and vertical displacement modes of the group pit support structure, and then simulate and analyze the influence of various lateral unloading methods of foundation pit excavation on the deformation of the adjacent group pit support structure, so as to achieve the effect of simulating multiple displacements of the group pit support structure.

[0016] As a further description of the above technical solution:

[0017] An array loading and unloading system (2) is provided on each side of the simulation box (1). The model box (1) is vertically placed on a third shell (21). The array loading and unloading system (2) is formed by first loading devices (3) arranged in an array. A first shell (22) with an opening design is used on one side of the model box shell (20) outside the array loading and unloading system.

[0018] The array loading and unloading system (2) is placed corresponding to the first housing (22), and connected to the water supply system (6) and the rubber module (5).

[0019] As a further description of the above technical solution:

[0020] The first loading device (3) is entirely composed of an electromagnetic thrust system (24) and a current loading system (23);

[0021] The current loading system (23) is composed of two electromagnetic coils (7), a laser displacement detector (8), a first circuit (9), and a second circuit (10);

[0022] The current can be applied to two different circuits by controlling the mobile phone or computer. By changing the magnitude and direction of the current in the different circuits, the first loading device (3) can apply a pulling force or a pushing force. The relationship diagram between the current I and the force F can be obtained by computer calculation.

[0023] A force is obtained through the current loading system (23), applied to the force transmission rod (12), pulling the spring (11) to move, and the displacement of the spring is detected by the laser displacement detector (8).

[0024] As a further description of the above technical solution:

[0025] A water pipe (13) is arranged in the spring (11), the water pipe (13) is separated from the spring (11) by a water pipe baffle (14), the water pipe (13) is connected to a water tank (19), a hole is opened on the baffle (25) at the top of the spring, the water pipe (13) is connected to an external water delivery device, a permeable stone (18) is filled between the water tank (19) and the rubber module (5), and the water tank (19) and the rubber module (5) are connected by screws (15). The rubber module (5) is composed of a permeable stone (18), a first rubber (16), a second rubber (17), and screws (15).

[0026] As a further description of the above technical solution:

[0027] A baffle (4) is placed between the array loading and unloading system (2) and the first housing (22). In normal use, the current loading system (23) is adjusted to change the current magnitude and direction, so that the electromagnetic thrust system (24) generates thrust and pull. The baffle (4) is used to balance the reaction force generated by the electromagnetic thrust system (24) to ensure that the electromagnetic test device (27) does not move during use.

[0028] When a first loading device (3) fails, it is necessary to replace the first loading device (3). In this test device, it is not necessary to replace all of them, but only to replace the damaged first loading device (3). The first loading devices (3) are arranged in an array, and each first loading device (3) works independently. When replacing the first loading device (3), the baffle (4) is moved to the corresponding position of the opening of the spring top baffle (25) to balance the horizontal thrust of the soil in the model box.

[0029] As a further description of the above technical solution:

[0030] The rubber module (5) is mainly used to explore the influence of shear force on the rubber module (5) under the action of shear force in different directions, so as to make the test results more intuitive.

[0031] As a further description of the above technical solution:

[0032] The electromagnetic test device and operation method for simulating the multi-position interaction of a group pit support structure according to the present invention include the following steps:

[0033] Step 1: Select the size and material of the spring (11), determine the number of turns of the two electromagnetic coils (7) required, and select the specifications of the laser displacement detector (8);

[0034] Step 2: combining the current loading system (23) and the electromagnetic thrust system (24) to form a first loading device (3);

[0035] Step 3: Arrange the first loading device (3) in an array to form an array loading and unloading system (2) of the specifications required for the experiment;

[0036] Step 4: Determine the size of the selected second rubber (17) and the first rubber (16), and the rubber and the water-permeable stone (18) form a single rubber plate (26);

[0037] Step 5: splicing the individual rubber sheets (26) to form a rubber module (5) of the specifications required for the experiment;

[0038] Step 6: Determine the specifications of the water pipe (13), the water pipe baffle (14), the spring top baffle (25), and the screw (15) in the water delivery system (6);

[0039] Step 7: Connect the water delivery system (6), the rubber module (5) and the array loading and unloading system (2) and place them on the third shell (21) of the model box;

[0040] Step 8: Install the baffle (4) to form an electromagnetic test device (27) that simulates the multi-position of the group pit support structure, and symmetrically install two identical test devices (27) on both sides of the model box (1) to form a foundation pit model box (1);

[0041] Step 9: placing 2 to 3 model boxes (1) at random locations and filling soil before different model boxes (1) to simulate multiple foundation pit excavation;

[0042] Step 10: changing the water depth in the model box (1) through the water delivery system (6) to simulate the groundwater in the foundation pit excavation and the influence of foundation pit dewatering on the excavation of multiple foundation pits;

[0043] Step 11: Close the circuit breaker and control the current loading system (23) via a mobile phone or computer to apply current, and then start the test;

[0044] Step 12: By changing the soil type before different model boxes (1) and the working state of the first loading device (3) at different positions, the influence of various foundation pit excavation lateral unloading methods on the deformation of the adjacent group pit support structure is simulated and analyzed.

[0045] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0046] (1) Different excavation methods are selected for different types of support structures, which have different effects on the settlement of the strata outside the support structure or the deformation of adjacent buildings. The present invention can simulate earth excavation. The device can also simulate the effect of the excavation of a new foundation pit on the original foundation pit. It can not only simulate the effect of foundation pit excavation on the strata on one side, but also simulate the mutual influence of the excavation of two adjacent foundation pits during the excavation of a group of pits, and can reflect the influence of the temporal and spatial effects of foundation pit excavation on the adjacent foundation pit support structure.

[0047] (2) The present invention realizes automatic control by controlling the current loading system (23). The corresponding program is input on a mobile phone or a computer to adjust the current applied by the current loading system (23). The electromagnetic thrust system (24) simulates the effects of different points in the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The three-dimensional structure diagram of the present invention

[0049] Figure 2 Model box shell diagram

[0050] Figure 3 Schematic diagram of the three-dimensional structure of the first loading device

[0051] Figure 4 Schematic diagram of the three-dimensional structure of the first loading device

[0052] Figure 5 Add baffle to the first loading device

[0053] Figure 6 for Figure 1 Schematic diagram of the local enlarged structure

[0054] Figure 7 Water delivery system diagram

[0055] Figure 8 A partial enlarged structural diagram of the rubber module

[0056] Fig. 9 for Figure 8 A partial enlarged view of

[0057] Fig.10 Connection diagram of spring and first loading device

[0058] In the figure: 1-model box, 2-array loading and unloading system, 3-first loading device, 4-baffle, 5-rubber module, 6-water delivery system, 7-electromagnetic coil, 8-laser displacement detector, 9-first circuit, 10-second circuit, 11-spring, 12-force transmission rod, 13-water delivery pipe, 14-water delivery pipe baffle, 15-screw, 16-first rubber, 17-second rubber, 18-permeable stone, 19-water tank, 20-model box shell, 21-third shell, 22-first shell, 23-current loading system, 24-electromagnetic thrust system, 25-spring top baffle, 26-single rubber plate, 27-total device, 28-second shell. DETAILED DESCRIPTION

[0059] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0060] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0061] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations.

[0062] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0063] In the present invention, terms such as "fixed", "connected", "connected", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances, and it cannot be understood as a limitation on the present invention.

[0064] The present invention provides a technical solution of an electromagnetic test device and an operation method for simulating the interaction of multiple displacements of a group pit support structure:

[0065] like Figure 1 , 3 As shown in , 5 and 6, an electromagnetic test device and an operation method for simulating the multi-variable interaction of a group pit support structure mainly include a model box (1), an array loading and unloading system (2), a rubber module (5), and a water delivery system (6). The array loading and unloading system (2) includes a first loading device (3), a baffle (4), a first circuit (9), a second circuit (10), a laser displacement detector (8), and an electromagnetic thrust system (24). The first loading device (3) is assembled according to the experimental specifications.

[0066] The array loading and unloading system (2) is stacked on the third housing (21) according to the specifications required for the experiment, and a baffle (4) is placed to connect the circuits to form a path. In this way, the current loading system (23) can be controlled on a mobile phone or computer to control the current in the circuit to control the force applied by the electromagnetic coil, and then the force is transmitted through the electromagnetic thrust system (24). In this way, the thrust and pull applied to the rubber module (5) can be controlled.

[0067] like Figure 1 , 3 As shown in , 4, and 6, the current loading system (23) is mainly composed of a first circuit (9), a second circuit (10), and a laser displacement detector (8). By establishing a program and writing a code, the current loading system (23) can be controlled through a mobile phone or a computer. By adjusting the mobile phone or the computer, the current size and direction in the first circuit (9) can be directly changed. The current size and direction of the second circuit (10) remain unchanged after the line switch is turned off. By establishing a mathematical model, a relationship diagram between current and force can be obtained. When conducting an experiment, the simulated force can be obtained by simply adjusting the size and direction of the applied current.

[0068] like Figure 1 , 5 As shown in , 6, and 7, a water supply system (6) is connected. The water supply system (6) is mainly composed of a spring top baffle (25), a water supply pipe (13), a water tank (19), and a permeable stone (18). The water supply system (6) is placed on the array loading and unloading system (2). The first loading device (3) adopts a drawer design. If an error occurs at a certain point in the array loading and unloading system (2), the first loading device (3) needs to be replaced. The baffle (4) needs to be pulled out and inserted into the corresponding position of the opening of the spring top baffle (25). The baffle (4) reduces the impact of the soil on the array loading and unloading system (2) when the first loading device (3) is replaced. Under normal use, the baffle (4) provides a reaction force for the array loading and unloading system (2) to keep the device stable during use.

[0069] like Figure 1 , 6 The rubber module (5) shown in FIGS. 8 and 9 is composed of a permeable stone (18), a second rubber (17), a first rubber (16), and a screw (15). The permeable stone (18) is connected to the water tank (19) through the screw (15), and the rubber module (5) and the water supply system (6) are integrated into a whole. The whole is placed on the array loading and unloading system (2) according to the specifications required for the experiment, and the current loading system (23) is controlled to apply the current. The magnitude of the applied force is transmitted through the electromagnetic thrust system (24), and thrust and tension are applied to the rubber module (5).

[0070] In this embodiment, based on the known force generated by two energized coils, the magnitude and direction of the force obtained are changed by adjusting the magnitude and direction of the applied current, thereby simulating the electromagnetic test device and operation method of the multi-position support structure of the group pit. The electromagnetic coil wrapping material of this experiment selects an insulated magnetic material such as plastic to reduce the influence of electromagnetic interference on the accuracy of the experiment. This experiment takes two circular electromagnetic coils (7) as an example, and controls them through a current loading system (23) to simulate the electromagnetic test device and operation method of the multi-position support structure of the group pit.

[0071] In this example, the selection of the rubber module (5) can be analyzed from different perspectives. This experiment mainly studies the effect of the rubber module (5) on the interaction between multiple foundation pits under the action of shear forces that can change the size and position.

[0072] In this example, the power source selected for the first circuit (9) should be a power source that can change the current size and direction and ensure that the current is constant with an error of no more than 1A. The power source selected for the second circuit (10) only needs to ensure that the current size is constant with an error of no more than 1A.

[0073] The present invention also provides an electromagnetic test device and an operation method for simulating multiple displacements of a group pit support structure, and a construction method of the experimental device, and the specific steps are as follows:

[0074] Step 1: Select the size and material of the spring (11), determine the number of turns of the two electromagnetic coils (7) required, and select the specifications of the laser displacement detector (8);

[0075] Step 2: combining the current loading system (23) and the electromagnetic thrust system (24) to form a first loading device (3);

[0076] Step 3: Arrange the first loading device (3) in an array to form an array loading and unloading system (2) of the specifications required for the experiment;

[0077] Step 4: Determine the size of the selected second rubber (17) and the first rubber (16), and the rubber and the water-permeable stone (18) form a single rubber plate (26);

[0078] Step 5: splicing the individual rubber sheets (26) to form a rubber module (5) of the specifications required for the experiment;

[0079] Step 6: Determine the specifications of the water pipe (13), the water pipe baffle (14), the spring top baffle (25), and the screw (15) in the water delivery system (6);

[0080] Step 7: Connect the water delivery system (6), the rubber module (5) and the array loading and unloading system (2) and place them on the third shell (21) of the model box;

[0081] Step 8: Install the baffle (4) to form an electromagnetic test device (27) that simulates the multi-position of the group pit support structure, and symmetrically install two identical test devices (27) on both sides of the model box (1) to form a foundation pit model box (1);

[0082] Step 9: placing 2 to 3 model boxes (1) at random locations and filling soil before different model boxes (1) to simulate multiple foundation pit excavation;

[0083] Step 10: changing the water depth in the model box (1) through the water delivery system (6) to simulate the groundwater in the foundation pit excavation and the influence of foundation pit dewatering on the excavation of multiple foundation pits;

[0084] Step 11: Close the circuit breaker and control the current loading system (23) via a mobile phone or computer to apply current, and then start the test;

[0085] Step 12: By changing the soil type before different model boxes (1) and the working state of the first loading device (3) at different positions, the influence of various foundation pit excavation lateral unloading methods on the deformation of the adjacent group pit support structure is simulated and analyzed.

[0086] During the construction of underground complexes, it is inevitable to face the problem of simultaneous or cross excavation of multiple foundation pits. The excavation of adjacent foundation pits will inevitably affect the adjacent foundation pit support structures. In addition, the lateral horizontal displacement of the support structure during the foundation pit excavation process is also quite different due to the different forms of foundation pit support structures. When two or more adjacent foundation pit support structures adopt different forms, the current simulation test cannot simultaneously achieve the working conditions of simultaneous excavation of different types of foundation pits. The present invention is precisely to solve the above problems.

[0087] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electromagnetic test device for simulating the interactive effects of multiple displacements of a group pit support structure, characterized in that: The invention is composed of a model box (1) and an array loading and unloading system (2) located on a third shell (21). The array loading and unloading system (2) is composed of a first loading device (3), and the first loading device (3) is composed of a current loading system (23) and an electromagnetic thrust system (24). Place a laser displacement detector (8) at the location of the spring (11) ， The compression or extension distance of the spring (11) is monitored. The spring (11) is connected to a water tank (19). A water pipe (13) is arranged in the spring (11). The water pipe (13) and the spring (11) are separated by a water pipe baffle (14). The water pipe (13) is connected to the water tank (19). The water tank (19) is connected to the rubber module (5) by a screw (15).

2. According to claim 1, an electromagnetic test device for simulating the interaction of multiple displacements of a group pit support structure is characterized in that: There is an array-type loading and unloading system (2) on each side of the simulation box (1). The model box (1) is vertically placed on the third shell (21). The array-type loading and unloading system (2) is formed by the first loading device (3) arranged in an array. The first shell (22), the second shell (28), and the third shell (21) constitute the model box shell (20). The array-type loading and unloading system (2) is placed corresponding to the first shell (22), connected to the water supply system (6), and the rubber module (5).

3. The electromagnetic test device for simulating the interaction of multiple displacements of a group pit support structure according to claim 1 is characterized in that: The first loading device (3) is composed of an electromagnetic thrust system (24) and a current loading system (23). The current loading system (23) is composed of two magnetic coils (7), a laser displacement detector (8), a first circuit (9), and a second circuit (10).

4. The electromagnetic test device for simulating multiple displacements of a group pit support structure according to claim 1 is characterized in that: The spring (11) has a water pipe (13) in it, the water pipe (13) is separated from the spring (11) by a water pipe baffle (14), the water pipe (13) is connected to a water tank (19), a hole is opened on the baffle (25) at the top of the spring, the water pipe (13) is connected to an external water supply device, a permeable stone (18) is filled between the water tank (19) and the rubber module (5), and the water tank (19) and the rubber module (5) are connected by screws (15). The rubber module (5) is composed of a permeable stone (18), a first rubber (16), a second rubber (17), and screws (15).

5. The electromagnetic test device for simulating the interaction of multiple displacements of a group pit support structure according to claim 1 is characterized in that: A baffle (4) is placed between the array-type loading and unloading system (2) and the first shell (22).

6. An operation method for simulating the interactive effects of multiple displacements of a group pit support structure, characterized in that: An electromagnetic test device and operation method for simulating the multi-variable position of a group pit support structure according to any one of claims 1 to 5, comprising the following steps: Step 1: Select the size and material of the spring (11), determine the number of turns of the two electromagnetic coils (7) required, and select the specifications of the laser displacement detector (8); Step 2: combining the current loading system (23) and the electromagnetic thrust system (24) to form a first loading device (3); Step 3: Arrange the first loading device (3) in an array to form an array loading and unloading system (2) of the specifications required for the experiment; Step 4: Determine the size of the selected second rubber (17) and the first rubber (16), and the rubber and the water-permeable stone (18) form a single rubber plate (26); Step 5: splicing the individual rubber sheets (26) to form a rubber module (5) of the specifications required for the experiment; Step 6: Determine the specifications of the water pipe (13), the water pipe baffle (14), the spring top baffle (25), and the screw (15) in the water delivery system (6); Step 7: Connect the water delivery system (6), the rubber module (5) and the array loading and unloading system (2) and place them on the third shell (21) of the model box; Step 8: Install the baffle (4) to form an electromagnetic test device (27) that simulates the multi-position of the group pit support structure, and symmetrically install two identical test devices (27) on both sides of the model box (1) to form a foundation pit model box (1); Step 9: placing 2 to 3 model boxes (1) at random locations and filling soil before different model boxes (1) to simulate multiple foundation pit excavation; Step 10: changing the water depth in the model box (1) through the water delivery system (6) to simulate the groundwater in the foundation pit excavation and the influence of foundation pit dewatering on the excavation of multiple foundation pits; Step 11: Close the circuit breaker and control the current loading system (23) via a mobile phone or computer to apply current, and then start the test; Step 12: By changing the soil type before different model boxes (1) and the working state of the first loading device (3) at different positions, the influence of various foundation pit excavation lateral unloading methods on the deformation of the adjacent group pit support structure is simulated and analyzed.

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