Device and method for monitoring horizontal displacement and pressure of soil at different depths in model test

Abstract

The present application belongs to the field of model test monitoring, and provides a device and method for monitoring horizontal displacement and pressure of soil at different depths in model test. The device for monitoring horizontal displacement and pressure of soil at different depths in model test comprises a monitor, a connecting rod, a pull wire and a displacement sheet; one end of the monitor is connected with the inner wall of a model test junction box, and the other end of the monitor is connected with the displacement sheet through the connecting rod; one end of the pull wire is connected with the displacement sheet, and the other end of the pull wire is connected with the monitor. The use method comprises the following steps: assembling elements; assembling the monitor; passing the other end of the connecting rod through the hole of the monitor shell, and then binding the other end of the pull wire with the outer ring of the spring, and keeping the pull wire in a straight state during the process; backfilling soil in layers and fixing the monitor on the inner wall of the model test box from top to bottom; leading the wire out and connecting it to the existing model test junction box to form a closed loop, and calculating the horizontal displacement and stress of soil at different depths.

Description

Technical Field

[0001] This invention relates to a device and method for monitoring horizontal displacement and pressure of soil at different depths in model tests, belonging to the field of model test monitoring technology. Background Technology

[0002] During underground engineering construction, such as foundation pit excavation, tunnel construction, and pile foundation drilling, the surrounding soil is often disturbed and displaced. Current methods for calculating and predicting horizontal soil displacement rely on simplistic models with excessive assumptions, making them difficult to reconcile with actual field conditions. Furthermore, the complexity of soil constitutive structure means that theoretical calculations often fail to accurately determine the magnitude of horizontal displacement in a specific soil layer. While on-site monitoring provides more direct data, it requires long monitoring cycles, is inefficient, and the inherent uncertainties of construction sites sometimes present significant challenges in data acquisition.

[0003] Model tests are simple to operate and highly controllable. The monitoring data can also be used to calculate the actual situation in the project based on the scaling ratio. However, for geotechnical model tests such as foundation pit excavation, tunnel construction and pile foundation drilling, there is currently no mature method for monitoring horizontal displacement and stress. Summary of the Invention

[0004] One of the objectives of this invention is to provide a device for monitoring horizontal displacement and pressure of soil at different depths for model testing.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A device for monitoring horizontal displacement and pressure of soil at different depths in a model test includes a monitor, a connecting rod, a wire, and a displacement plate; one end of the monitor is connected to the inner wall of the model test junction box, and the other end of the monitor is connected to the displacement plate through the connecting rod; one end of the wire is connected to the displacement plate, and the other end is connected to the monitor.

[0007] The preferred embodiment of the device for monitoring horizontal displacement and pressure of soil at different depths for the model test includes a monitoring instrument comprising a housing, a resistance wire, a spring, a junction box, and wires.

[0008] The two ends of the resistance wire are connected to junction boxes, which are glued to the inner wall of the housing.

[0009] One end of the spring is fixed to the inner wall of the monitor, and the other end is connected to the resistance wire through a slider;

[0010] One of the wires is connected to the slider, and the other is connected to the resistance wire through the junction box, and then passes through the monitoring instrument housing to connect to the model test junction box.

[0011] The preferred scheme for the device used in the model test to monitor the horizontal displacement and pressure of the soil at different depths is that one end of the pull wire is fixed to the protrusion of the displacement plate, and the other end is bound to the outer ring of the spring.

[0012] The preferred embodiment of the device for monitoring horizontal displacement and pressure of soil at different depths in the model test is that one end of the connecting rod is connected to the displacement plate by a thread, and the other end passes through the monitoring instrument hole and enters the monitoring instrument.

[0013] The preferred embodiment of the device for monitoring horizontal displacement and pressure of soil at different depths in the model test is a circular thin plate.

[0014] The preferred embodiment of the device for monitoring horizontal displacement and pressure of soil at different depths in the model test is that the monitoring instrument is fixed to the wall of the model test chamber by bolts.

[0015] The preferred embodiment of the device for monitoring horizontal displacement and pressure of soil at different depths in the model test is provided, wherein the pull wire and displacement plate are made of steel, and the connecting rod is made of PVC pipe.

[0016] The second objective of this invention is to provide a method for using a device for monitoring horizontal displacement and pressure at different depths of soil in model tests.

[0017] To achieve the above objectives, the present invention employs the following technical solution:

[0018] A method for using a device for monitoring horizontal displacement and pressure at different depths of soil in a model test includes the following steps:

[0019] Step 1: Assemble the components; connect one end of the pull wire to the displacement plate, and then connect one end of the connecting rod to the displacement plate through a thread;

[0020] Step 2: Assemble the monitor; fix both ends of the resistance wire to the junction box, fix one end of the spring to the inner wall of the monitor, and connect the other end to the resistance wire through the slider; connect the wires to the junction box and the slider respectively.

[0021] Step 3: Pass the other end of the connecting rod through the hole in the monitor housing, and then tie the other end of the pull wire to the outer ring of the spring, keeping the pull wire taut during the process;

[0022] Step 4: Backfill the soil in layers and fix the monitoring instrument to the inner wall of the model test chamber from top to bottom;

[0023] Step 5: Lead out the wires and connect them to the existing model test junction box to form a closed loop. After powering on, monitor the change in resistance of the resistance wire as the slider moves on the computer terminal. Combine the spring deformation characteristics to calculate the horizontal displacement and stress at different depths of the soil.

[0024] The advantages of this invention are:

[0025] 1. This invention, through the combination of resistance wire and spring, connects to an existing model test junction box and computer, enabling accurate monitoring of horizontal displacement and stress magnitude at different depths during model tests.

[0026] 2. This invention is applicable to various soil unloading conditions such as foundation pit excavation, tunnel construction, and pile foundation drilling, and the monitoring depth can be determined according to the test requirements. This invention is easy to install, accurate in measurement, and reusable. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0028] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

[0029] Figure 2 This is a schematic diagram of the internal structure of the resistive horizontal displacement and stress monitoring instrument according to Embodiment 1 of the present invention.

[0030] Figure 3 This is a schematic diagram of part of the connecting rod and displacement plate in Embodiment 1 of the present invention.

[0031] Among them: resistive horizontal displacement and stress monitoring instrument-1, connecting rod-2, pull wire-3, displacement plate-4, model test box wall-5, foundation pit, bored pile, tunnel and other soil excavation related projects-6, monitoring instrument shell-101, resistance wire-102, spring-103, junction box-104, bolt-105, slider-106, wire-107. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, terms such as "upper," "lower," "left," "right," "inner," "outer," "bottom," and "top" indicating orientation or location are based on the orientation shown in the accompanying drawings and are only for the purpose of simplifying the description. They are not intended to indicate or imply that the invention must have a specific orientation or location. All connection / fixing relationships involved in this invention do not refer to direct connection of components, but rather to the optimal connection / fixing method that can be adopted according to the specific implementation situation.

[0034] This invention uses a foundation pit excavation model test as an example for illustration, but it is not limited to this one working condition. This invention is applicable to any model test involving disturbance to the surrounding soil and horizontal unloading of the soil in geotechnical model tests, such as tunnel construction and pile foundation drilling.

[0035] Example 1

[0036] refer to Figure 1 , Figure 2 and Figure 3 A device for monitoring horizontal displacement and pressure of soil at different depths for model testing includes a monitoring instrument 1, a connecting rod 2, a pull wire 3, and a displacement plate 4; the displacement plate 4 is connected to one end of the connecting rod 2 and the other end is connected to the monitoring instrument 1; one end of the pull wire 3 is connected to the displacement plate 4 and the other end is connected to a spring 103.

[0037] The monitoring instrument 1 includes a housing 101, a resistance wire 102, a spring 103, a junction box 104, and a wire 107. The two ends of the resistance wire 102 are respectively connected to the junction box 104, and the junction box 104 is glued to the inner wall of the housing 101. One end of the spring 103 is fixed to the inner wall of the monitoring instrument 1, and the other end is connected to the resistance wire 102 through a slider 106. One of the wires 107 is connected to the slider 106, and the other is connected to the resistance wire 102 through the junction box 104, and passes through the housing 101 of the monitoring instrument to connect to the model test junction box 5.

[0038] In this embodiment, one end of the connecting rod 2 is threaded. During installation, the connecting rod 2 passes through the pull wire hole and is connected to the displacement plate 4 via the thread, while the other end passes into the inside of the monitor 1. The outer diameter of the connecting rod 2 is the same as the opening size of the outer shell of the monitor 1, ensuring that the connecting rod 2 can slide normally in the monitor and can protect the pull wire 3, ensuring that the pull wire 3 remains horizontal and taut throughout the model test. The purpose is to ensure that the pull wire can synchronously pull the spring as the displacement plate moves.

[0039] In this embodiment, the monitoring instrument 1 is equipped with a resistance wire 102. The resistance value corresponding to different lengths of the resistance wire 102 has been determined in advance. The resistance value in the circuit is changed by moving the slider 106. The magnitude of the horizontal displacement at that depth can be determined by the magnitude of the resistance value change. The resistance wire 102 is connected to the wire 107 through the junction box 104 and the slider 106 respectively. The wire 107 passes through the monitoring instrument 1 and is connected to the existing model test junction box 5 to form a closed loop. The resistance value change of the resistance wire is displayed on the model test computer.

[0040] In this embodiment, one end of the pull wire 3 is fixed to the protrusion of the displacement plate 4, and the other end is bound to the outer ring of the spring 103. During this period, the pull wire is kept in a horizontal and straight state. The purpose is to ensure that the pull wire can pull the spring to move synchronously when it moves with the displacement plate.

[0041] In this embodiment, the displacement plate 4 is a circular thin plate with a certain thickness. The circular design facilitates backfilling of soil and ensures a sufficient bearing area, guaranteeing that the displacement plate can move with the soil when it moves horizontally. The monitoring instrument 1 is fixed to the wall 5 of the model test chamber by bolts 105. The pull wire 3 and the displacement plate 4 are both made of steel, and the connecting rod 2 is a PVC pipe.

[0042] Example 2

[0043] This embodiment discloses a method for using a device for monitoring horizontal displacement and pressure of soil at different depths in a model test, as described in Embodiment 1, including the following steps:

[0044] Step 1: Assemble the components; connect one end of the pull wire 3 to the displacement plate 4, and then connect one end of the connecting rod 2 to the displacement plate (4) through a thread;

[0045] Step 2: Assemble the monitor 1; fix both ends of the resistance wire 102 to the junction box 104 respectively, fix one end of the spring 103 to the inner wall of the monitor, and connect the other end to the resistance wire 102 through the slider 106. Connect the wire 107 to the junction box (104) and the slider 106 respectively.

[0046] Step 3: Pass the other end of the connecting rod 2 through the hole in the monitor housing, and then bind the other end of the pull wire 3 to the outer ring of the spring 103, keeping the pull wire taut during the process;

[0047] Step 4: Backfill the soil in layers and fix the monitoring instrument 1 to the inner wall of the model test chamber 5;

[0048] Step 5: Lead out wires 107 and connect them to the existing model test junction box 5 to form a closed loop. After powering on, monitor the change in resistance of the resistance wire as it moves with the slider 106 on the computer terminal. Combine the spring deformation characteristics to calculate the horizontal displacement and stress at different depths of the soil.

[0049] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for using a device for monitoring horizontal displacement and pressure of soil at different depths in a model test, characterized in that, Includes the following steps: Step 1: Assemble the components; connect one end of the pull wire (3) to the displacement plate (4), and then connect one end of the connecting rod (2) to the displacement plate (4) through a thread; Step 2: Assemble the monitor (1); fix both ends of the resistance wire (102) to the junction box (104) respectively, fix one end of the spring (103) to the inner wall of the monitor, and connect the other end to the resistance wire (102) through the slider (106). Connect the wire (107) to the junction box (104) and the slider (106) respectively. Step 3: Pass the other end of the connecting rod (2) through the hole in the monitor housing, and then bind the other end of the pull wire (3) to the outer ring of the spring (103), keeping the pull wire taut during the process; Step 4: Backfill the soil in layers and fix the monitoring instrument (1) to the inner wall of the model test box (5) from top to bottom; Step 5: Lead out the wires (107) and connect them to the existing model test junction box (5) to form a closed loop. After powering on, monitor the change in resistance value of the resistance wire as it moves with the slider (106) on the computer terminal. Combine the spring deformation characteristics to calculate the horizontal displacement and stress at different depths of the soil. The device includes a monitor (1), a connecting rod (2), a pull wire (3), and a displacement plate (4); one end of the monitor (1) is connected to the inner wall of the model test junction box (5), and the other end of the monitor (1) is connected to the displacement plate (4) through the connecting rod (2); one end of the pull wire (3) is connected to the displacement plate (4), and the other end is connected to the monitor (1). The monitoring instrument (1) includes a housing (101), a resistance wire (102), a spring (103), a junction box (104), and a wire (107). The two ends of the resistance wire (102) are respectively connected to the junction box (104), and the junction box (104) is glued to the inner wall of the housing (101); One end of the spring (103) is fixed to the inner wall of the monitor (1), and the other end is connected to the resistance wire (102) through the slider (106); One of the wires (107) is connected to the slider (106), and the other is connected to the resistance wire (102) through the junction box (104) and passes through the monitoring instrument housing (101) to connect to the model test junction box (5).

2. The method of using the apparatus for monitoring horizontal displacement and pressure at different depths of soil mass in a model test according to claim 1, wherein: One end of the pull wire (3) is fixed to the protrusion of the displacement plate (4), and the other end is bound to the outer ring of the spring (103).

3. The method of using the device for monitoring horizontal displacement and pressure of soil at different depths in a model test according to claim 1, characterized in that: One end of the connecting rod (2) is connected to the displacement plate (4) by a thread, and the other end is inserted into the monitor through the hole of the monitor (1).

4. The method of using the apparatus for monitoring horizontal displacement and pressure at different depths of soil mass in a model test according to claim 1, wherein: The displacement plate (4) is a circular thin plate. 5.The method of using the device for monitoring horizontal displacement and pressure at different depths of soil mass in a model test according to claim 1, wherein: The monitoring instrument (1) is fixed to the wall (5) of the model test chamber by bolts (105). 6.The method of using the device for monitoring horizontal displacement and pressure of soil at different depths according to any one of claims 1-5, characterized in that: The pull wire (3) and displacement plate (4) are both made of steel, and the connecting rod (2) is made of PVC pipe.

Images