Limited soil pressure model test device

Abstract

The utility model discloses a finite soil pressure model test device, including model box, movable baffle, fixed baffle, adjustable inner support subassembly and monitoring component, and model box is equipped with a plurality of installation sites, fixed baffle and movable baffle are spaced apart distribution in model box along the first direction, and fixed baffle is detachably connected with model box corresponding one installation site, adjustable inner support subassembly includes a plurality of inner support units, and each inner support unit includes a plurality of inner support structures, and inner support structure is connected with model box, movable baffle, and the pressure that applies to movable baffle is adjustable, monitoring component includes a plurality of first strain gauges, a plurality of second strain gauges, a plurality of micrometers and a plurality of soil pressure boxes, and first strain gauge is located movable baffle, and second strain gauge is located inner support structure, and micrometer is located test soil body upper surface, and soil pressure box is located test soil body inside, can carry out the finite soil pressure test under the different finite soil body width, support length, enclosure structure deformation mode.

Description

Technical Field

[0001] This utility model relates to the field of physical model testing technology for earth pressure, and specifically to a finite earth pressure model testing device. Background Technology

[0002] With the development of urban underground engineering, many foundation pits adjacent to existing underground structures have emerged, making finite earth pressure a widely concerned issue. Currently, the calculation of earth pressure in foundation pits typically employs Rankine or Coulomb earth pressure theories, which assume a semi-infinite space behind the retaining wall. However, in actual engineering projects, the soil behind the retaining wall of a foundation pit adjacent to an existing underground structure has a finite width, failing to meet the assumption of a semi-infinite space. Therefore, a finite earth pressure model test device that can reflect the actual engineering conditions is needed.

[0003] Existing finite earth pressure model test devices can simulate various finite soil widths and different retaining wall displacements, but they have some shortcomings: they cannot consider the influence of internal supports on the foundation pit, while in actual engineering, foundation pits often have multiple internal supports; existing test devices can only consider the translation of the retaining wall and its rotation around the top and bottom of the wall, while in actual engineering, the deformation modes of foundation pit retaining structures are mostly cantilever, convex, combined, and kick-toe deformation modes, which cannot simulate the deformation modes of retaining structures under actual working conditions; and they cannot consider the magnitude and distribution of finite earth pressure below the excavation surface of the foundation pit. Utility Model Content

[0004] The main purpose of this invention is to propose a finite earth pressure model test device to solve the above-mentioned problems.

[0005] To achieve the above objectives, this utility model proposes a finite earth pressure model test device, comprising: A model box containing test soil is provided. The model box is rectangular and has a first side wall and a second side wall that are opposite to each other in a first direction. The model box has multiple mounting positions that are spaced apart along the first direction. An movable baffle is installed inside the model box and extends vertically to simulate the retaining structure of the foundation pit. A fixed baffle is disposed inside the model box and extends in the vertical direction, and is spaced apart from the movable baffle in the first direction. The fixed baffle is disposed on the side of the movable baffle away from the first side wall, and is detachably connected to the model box corresponding to one of the plurality of mounting positions, for controlling the limited soil width. An adjustable internal support assembly includes a plurality of internal support units spaced apart along the vertical direction, each internal support unit including a plurality of internal support structures spaced apart along the second direction, one end of each internal support structure being connected to the first sidewall and the other end being connected to the movable baffle, and the pressure applied by the internal support structure to the movable baffle is adjustable; and, The monitoring component includes multiple first strain gauges, multiple second strain gauges, multiple dial gauges, and multiple earth pressure cells. The multiple first strain gauges are respectively disposed on both sides of the movable baffle in the first direction for monitoring the horizontal displacement of the movable baffle. The multiple second strain gauges are respectively disposed on the multiple internal support structures for monitoring the axial force of the internal support structures. The multiple dial gauges are disposed on the upper surface of the test soil located between the movable baffle and the fixed baffle, and are distributed at intervals along the first direction for monitoring the vertical displacement of the test soil. The earth pressure cells are embedded in the test soil located between the movable baffle and the fixed baffle for monitoring earth pressure. Among them, the first direction, the second direction, and the up and down directions are perpendicular to each other.

[0006] Optionally, the internal support structure includes a support rod and a screw jack. The support rod extends along the first direction and has a first connecting end and a second connecting end. The first connecting end is connected to the movable baffle. The base of the screw jack is connected to the first side wall, and the top seat of the screw jack is connected to the second connecting end of the support rod for driving the support rod to move along the first direction.

[0007] Optionally, the model box includes a box frame, a bottom plate, a first side plate, a second side plate, and two tempered glass plates. The box frame is arranged in the shape of a cuboid. The bottom plate is installed at the bottom of the box frame. The first side plate and the second side plate are respectively disposed on both sides of the box frame in a first direction to form the first side wall and the second side wall. The two tempered glass plates are installed on both sides of the box frame in a second direction. The housing frame has multiple mounting holes in the first direction to form multiple mounting positions, and the fixing baffle is threadedly connected to the housing frame with bolts corresponding to one of the mounting holes.

[0008] Optionally, the distance between any two adjacent installation positions among the plurality of installation positions is set to 0.1H, and the distance between the installation position closest to the second sidewall and the second sidewall among the plurality of installation positions is set to 0.1H, where H is the excavation depth of the foundation pit.

[0009] Optionally, the spacing between any two adjacent internal support units among the plurality of internal support units is set to 0.2H, and the spacing between the internal support unit furthest from the bottom of the model box and the surface of the foundation pit is set to 0.2H, where H is the excavation depth of the foundation pit.

[0010] Optionally, the first strain gauges disposed on both sides of the movable baffle in the first direction are arranged corresponding to the centerline of the movable baffle; In the plurality of first strain gauges spaced apart in the vertical direction, the spacing between any two adjacent first strain gauges is set to 0.25H, and the upper end of the movable baffle is provided with a first strain gauge on each side in the first direction, wherein H is the excavation depth of the foundation pit.

[0011] Optionally, the distance between any two adjacent dial gauges in the plurality of dial gauges is set to 0.1H, and the distance between the dial gauge closest to the movable baffle and the movable baffle in the plurality of dial gauges is set to 0.1H, where H is the excavation depth of the foundation pit.

[0012] Optionally, each of the earth pressure cells is positioned corresponding to the centerline of the movable baffle; In the plurality of earth pressure cells that are spaced apart in the vertical direction, the distance between any two adjacent earth pressure cells is set to 0.25H, and the distance between the earth pressure cell at the top and the top of the movable baffle is set to 0.125H, where H is the excavation depth of the foundation pit.

[0013] Optionally, the test soil is prepared by mixing silt, barite powder, bentonite, double-flying powder and talc powder.

[0014] Optionally, the movable baffle is an aluminum alloy plate; The fixed baffle is made of steel plate.

[0015] In the technical solution of this utility model, the fixed baffle can be detachably connected to the model box at one of the multiple installation positions, realizing the adjustable position of the fixed baffle, that is, the distance between the fixed baffle and the movable baffle can be adjusted, so as to realistically simulate the finite soil width in actual engineering. The movable baffle is set to simulate the foundation pit retaining structure, and the adjustable internal support assembly, i.e., multiple internal support structures, applies different pressures to different positions of the movable baffle, thereby effectively simulating different deformation modes of the foundation pit retaining structure in actual engineering. Furthermore, the first strain gauge, the second strain gauge, the dial gauge, and the earth pressure cell are set to monitor the magnitude and distribution of the active earth pressure below the excavation surface of the foundation pit, accurately reflecting the stress condition of the foundation pit retaining structure under actual working conditions. Thus, the finite earth pressure model test device provided by this utility model can conduct finite earth pressure tests with different finite soil widths, different internal support lengths, and different retaining structure deformation modes, thereby accurately reproducing the excavation and support process of the foundation pit on site, ensuring the accuracy of the model test, and providing support for the study of finite earth pressure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A front view of an embodiment of the finite earth pressure model test apparatus provided by this utility model; Figure 2 for Figure 1 Side view of the test setup for a medium-limited earth pressure model; Figure 3 for Figure 1 Top view of the test setup for the finite earth pressure model; Figure 4 for Figure 1 Partial structural diagram of the finite earth pressure model test apparatus.

[0018] Explanation of icon numbers:

[0019] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0023] With the development of urban underground engineering, many foundation pits adjacent to existing underground structures have emerged, making finite earth pressure a widely concerned issue. Currently, the calculation of earth pressure in foundation pits typically employs Rankine or Coulomb earth pressure theories, which assume a semi-infinite space behind the retaining wall. However, in actual engineering projects, the soil behind the retaining wall of a foundation pit adjacent to an existing underground structure has a finite width, failing to meet the assumption of a semi-infinite space. Therefore, a finite earth pressure model test device that can reflect the actual engineering conditions is needed.

[0024] Existing finite earth pressure model test devices can simulate various finite soil widths and different retaining wall displacements, but they have some shortcomings: they cannot consider the influence of internal supports on the foundation pit, while in actual engineering, foundation pits often have multiple internal supports; existing test devices can only consider the translation of the retaining wall and its rotation around the top and bottom of the wall, while in actual engineering, the deformation modes of foundation pit retaining structures are mostly cantilever, convex, combined, and kick-toe deformation modes, which cannot simulate the deformation modes of retaining structures under actual working conditions; and they cannot consider the magnitude and distribution of finite earth pressure below the excavation surface of the foundation pit.

[0025] In view of this, the present invention provides a finite earth pressure model test device 100. Figures 1 to 4 An embodiment of the finite earth pressure model test device 100 provided by this utility model.

[0026] Please see Figures 1 to 4The finite earth pressure model test device 100 includes a model box 1, a movable baffle 2, a fixed baffle 3, an adjustable internal support assembly, and a monitoring assembly 4. The model box 1 contains test soil. The model box 1 is rectangular and has a first sidewall and a second sidewall opposite to each other in a first direction. Multiple mounting positions are provided on the model box 1, spaced apart along the first direction. The movable baffle 2 is located inside the model box 1 and extends vertically to simulate the retaining structure of a foundation pit. The fixed baffle 3 is located inside the model box 1 and extends vertically, spaced apart from the movable baffle 2 along the first direction. The fixed baffle 3 is located on the side of the movable baffle 2 away from the first sidewall and is detachably connected to the model box 1 corresponding to one of the multiple mounting positions, used to control the width of the finite soil mass. The adjustable internal support assembly includes multiple internal support units spaced apart along the vertical direction, and each internal support unit includes multiple internal support structures spaced apart along the second direction. The internal support structure 5 has one end connected to the first sidewall and the other end connected to the movable baffle 2, and the pressure applied by the internal support structure 5 to the movable baffle 2 is adjustable; the monitoring component 4 includes multiple first strain gauges 41, multiple second strain gauges 42, multiple dial gauges 43, and multiple earth pressure cells 44. The multiple first strain gauges 41 are respectively disposed on both sides of the movable baffle 2 in the first direction for monitoring the horizontal displacement of the movable baffle 2. The multiple second strain gauges 42 are respectively disposed on the multiple internal support structures 5 for monitoring the axial force of the internal support structures 5. The multiple dial gauges 43 are disposed on the upper surface of the test soil located between the movable baffle 2 and the fixed baffle 3, and are distributed at intervals along the first direction for monitoring the vertical displacement of the test soil. The earth pressure cells 44 are embedded in the test soil located between the movable baffle 2 and the fixed baffle 3 for monitoring earth pressure; wherein, the first direction, the second direction, and the vertical direction are mutually perpendicular to each other.

[0027] In this utility model's technical solution, the fixed baffle 3 can be detachably connected to the model box 1 at one of the multiple installation positions, making the position of the fixed baffle 3 adjustable. That is, the distance between the fixed baffle 3 and the movable baffle 2 is adjustable, thereby realistically simulating the limited soil width in actual engineering. Furthermore, the movable baffle 2 is set to simulate the foundation pit retaining structure, and the adjustable internal support assembly, i.e., multiple internal support structures 5, applies different pressures to different positions of the movable baffle 2, thereby effectively simulating different deformation modes of the foundation pit retaining structure in actual engineering. Furthermore, by setting up a first strain gauge 41, a second strain gauge 42, a dial gauge 43, and an earth pressure cell 44, the magnitude and distribution of active earth pressure below the excavation surface of the foundation pit can be monitored, accurately reflecting the stress condition of the foundation pit retaining structure under actual working conditions. Thus, the finite earth pressure model test device 100 provided by this utility model can conduct finite earth pressure tests under different finite soil widths, different internal support lengths, and different retaining structure deformation modes, thereby accurately reproducing the excavation and support process of the foundation pit on site, ensuring the accuracy of the model test, and providing support for the study of finite earth pressure.

[0028] For further details, please refer to Figures 1 to 3 The model box 1 includes a box frame 11, a bottom plate 12, a first side plate 13, a second side plate 14, and two tempered glass plates 15. The box frame 11 is rectangular. The bottom plate 12 is installed at the bottom of the box frame 11. The first side plate 13 and the second side plate 14 are respectively located on both sides of the box frame 11 in a first direction, forming the first side wall and the second side wall. The two tempered glass plates 15 are installed on both sides of the box frame 11 in a second direction to facilitate observation of soil deformation and damage during the test.

[0029] More specifically, the box frame 11 is welded from 12 angle steels, and the first side plate 13, the second side plate 14, and the bottom plate 12 are all steel plates welded to the box frame 11. More specifically, in one embodiment of this utility model, the box frame 11 is made of 12mm thick hot-rolled equilateral angle steel, and its dimensions are 1.5m long × 1m wide × 1m high. The first side plate 13, the second side plate 14, and the bottom plate 12 are all made of 12mm thick Q235 steel plates, and the tempered glass plate 15 has a thickness of 12mm.

[0030] Furthermore, the detachable connection method between the fixed baffle 3 and the model box 1 is not limited; it can be a threaded connection, a snap-fit ​​connection, etc. For details, please refer to [link / reference]. Figure 1In one embodiment of this utility model, the box frame 11 has multiple mounting holes 111 in the first direction, forming multiple mounting positions. The fixing baffle 3 is threadedly connected to the box frame 11 with bolts corresponding to one of the mounting holes 111, facilitating quick adjustment of the position of the fixing baffle 3. More specifically, multiple mounting holes 111 are provided on two angle steels at the top and two angle steels at the bottom and two angle steels at the second direction, both spaced apart along the first direction. Threaded holes are provided at both the upper and lower ends of the fixing baffle 3, so that the fixing baffle 3 and the box frame 11 are fixedly connected by bolts.

[0031] It should be noted that the distance between the fixed baffle 3 and the movable baffle 2 gradually increases, simulating the state of the soil width behind the retaining wall of the foundation pit from finite to semi-infinite.

[0032] For details, please refer to Figure 1 , Figure 3 and Figure 4 The inner support structure 5 includes a support rod 51 and a screw jack 52. The support rod 51 extends along the first direction and has a first connecting end and a second connecting end. The first connecting end is connected to the movable baffle 2. The base of the screw jack 52 is connected to the first side wall, and the top seat of the screw jack 52 is connected to the second connecting end of the support rod 51 to drive the support rod 51 to move along the first direction. In this way, the overall length of the inner support structure 5 in the first direction is adjustable, and the pressure on the part of the movable baffle 2 corresponding to the inner support structure 5 is also adjustable, realizing the loading and unloading of the movable baffle 2, thereby effectively simulating different deformation modes of the foundation pit retaining structure in actual engineering.

[0033] It should be noted that, depending on the test requirements, the lengths of the multiple inner support structures 5 in the adjustable inner support assembly may be different, the same, or partially the same and partially different. Similarly, the pressures exerted by the multiple inner support structures 5 on the movable baffle 2 may also be different, the same, or partially the same and partially different.

[0034] It should also be noted that the spiral jack 52 drives the support rod 51 to move towards the movable baffle 2, which can realize the passive earth pressure state of the soil behind the wall, and conversely, the active earth pressure state. Different deformation modes of the retaining structure can be achieved by changing the support length. At different heights, the spiral jack 52 drives the support rod 51 to different displacements, causing the movable baffle 2 to undergo different deformation modes, effectively simulating the different deformation modes of the foundation pit retaining structure in actual engineering.

[0035] Specifically, the connection method between the support rod 51 and the screw jack 52, the movable baffle 2, and the connection method between the screw jack 52 and the first side wall are not limited. They can be threaded connections, snap-fit ​​connections, welding, etc.

[0036] For further details, please refer to Figure 1 , Figure 3 and Figure 4 Based on the embodiment described above, which states that "the model box 1 includes a box frame 11, a bottom plate 12, a first side plate 13, a second side plate 14, and two tempered glass plates 15, the box frame 11 is rectangular, the bottom plate 12 is installed at the bottom of the box frame 11, the first side plate 13 and the second side plate 14 are respectively disposed on both sides of the box frame 11 in a first direction to form the first side wall and the second side wall, and the two tempered glass plates 15 are installed on both sides of the box frame 11 in a second direction," the inner support structure 5 further includes a support base plate 53. The first side plate 13 and the support base plate 53 are connected by bolts and threads. The support base plate 53 is fixedly connected to the base of the screw jack 52. The support rod 51 is threadedly connected to the top seat of the screw jack 52 and welded to the movable baffle 2.

[0037] Specifically, the support rod 51 is an aluminum alloy component.

[0038] Specifically, the distance between any two adjacent installation positions among the plurality of installation positions is set to 0.1H, and the distance between the installation position closest to the second sidewall and the second sidewall is also set to 0.1H, where H is the excavation depth of the foundation pit. This simulates the horizontal arrangement of supports within the foundation pit in actual engineering.

[0039] More specifically, in one embodiment of this utility model, the model box 1 is provided with 10 mounting positions along the first direction, so the width of the limited soil behind the movable baffle 2 can be 0.1H, 0.2H, 0.3H, 0.4H, 0.5H, 0.6H, 0.7H, 0.8H, 0.9H, or 1.0H.

[0040] Specifically, the spacing between any two adjacent internal support units is set to 0.2H, and the spacing between the internal support unit furthest from the bottom of the model box 1 and the surface of the foundation pit is also set to 0.2H, where H is the excavation depth of the foundation pit. This simulates the vertical arrangement of internal supports in an actual engineering project.

[0041] Specifically, the first strain gauges 41 located on both sides of the movable baffle 2 in the first direction are positioned corresponding to the centerline of the movable baffle 2; among the plurality of first strain gauges 41 spaced apart in the vertical direction, the spacing between any two adjacent first strain gauges 41 is set to 0.25H, and the upper end of the movable baffle 2 is provided with one first strain gauge on each side in the first direction, where H is the excavation depth of the foundation pit. In this way, the horizontal displacement and bending moment of the retaining structure can be measured.

[0042] It should be noted that the multiple first strain gauges 41 located on both sides of the movable baffle 2 in the first direction correspond one-to-one.

[0043] Specifically, the distance between any two adjacent dial gauges 43 is set to 0.1H, and the distance between the dial gauge 43 closest to the movable baffle 2 and the movable baffle 2 is also set to 0.1H, where H is the excavation depth of the foundation pit. In this way, surface settlement at different locations outside the foundation pit can be measured.

[0044] Specifically, the multiple earth pressure cells 44 are all positioned corresponding to the centerline of the movable baffle 2. Among the multiple earth pressure cells 44 spaced apart in the vertical direction, the distance between any two adjacent earth pressure cells 44 is set to 0.25H, and the distance between the top earth pressure cell 44 and the top of the movable baffle 2 is set to 0.125H, where H is the excavation depth of the foundation pit. In this way, the earth pressure on the soil-facing side of the retaining structure above and below the excavation surface of the foundation pit can be measured.

[0045] Specifically, the test soil was prepared by mixing silt, barite powder, bentonite, double-flying powder and talc powder.

[0046] It should be noted that the test soil was prepared according to a certain proportion based on the engineering geological conditions of the foundation pit site.

[0047] Specifically, the movable baffle 2 is an aluminum alloy plate; the fixed baffle 3 is a steel plate.

[0048] The test method of the finite earth pressure model test device 100 provided by this utility model includes the following steps: Step S1: Symmetrically attach multiple first strain gauges 41 to both sides of the movable baffle 2, and attach multiple earth pressure cells 44 to the soil-facing side of the movable baffle 2; fix the support rod 51 and the support base plate 53 to the spiral jack 52; configure the test soil according to the engineering geological conditions of the foundation pit site.

[0049] Step S2: Construct the box frame 11 using angle steel, and install the first side plate 13, the second side plate 14, and two tempered glass plates 15 on the box frame 11 to form the model box 1; draw the position of the movable baffle 2, the adjustable internal support assembly, the test soil surface, and the foundation pit on the tempered glass plate 15.

[0050] Step S3: Fill the model box 1 with the test soil up to the bottom of the movable baffle 2, and compact it with a heavy hammer.

[0051] Step S4: Install the movable baffle 2 and the fixed baffle 3, fill the test soil in layers and compact it with a heavy hammer, let it stand for 24 hours, and install multiple dial gauges 43 on the upper surface of the test soil.

[0052] Step S5: Excavate the test soil in layers to the bottom of each inner support unit, then install the inner support structure 5 on the first side plate 13, rotate the screw jack 52 so that the first connecting end of the support rod 51 abuts against the movable baffle 2, then weld the support rod 51 to the movable baffle 2, and attach the second strain gauge 42 to the middle of the support rod 51.

[0053] It should be noted that in this step, after each layer is excavated and the internal support structure 5 is installed, the model is left to stand for 1 hour before sensor readings are taken. This layered excavation and installation of the internal support structure 5 continues until the foundation pit excavation is complete.

[0054] Step S6: Adjust the length of each internal support structure 5 according to the test plan.

[0055] It should be noted that different deformation modes of the enclosure structure are achieved by adjusting the length of each internal support structure 5. For example, the four internal support structures 5 from top to bottom are designated as the 1st, 2nd, 3rd, and 4th internal support structures 5. Correspondingly, for the cantilever type, the 1st to 4th internal support structures 5 are shortened by 4mm, 3mm, 2mm, and 1mm respectively; for the convex type, the lengths of the 1st and 4th internal support structures 5 remain unchanged, while the 2nd and 3rd internal support structures 5 are shortened by 3mm; for the combined type, the 1st internal support structure 5 is shortened by 1mm, and the 2nd and 3rd internal support structures 5 are shortened by 3mm; for the skirting type, the length of the 1st internal support structure 5 remains unchanged, while the 2nd to 4th internal support structures 5 are shortened by 1mm, 2mm, and 3mm respectively.

[0056] Step S7: Remove the test soil, remove the fixed baffle 3, change the distance between the fixed baffle 3 and the movable baffle 2, repeat the above steps, and carry out finite earth pressure tests under different finite soil widths, different internal support lengths, and different retaining structure deformation modes.

[0057] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A finite earth pressure model test apparatus, characterized in that, The finite earth pressure model test apparatus includes: A model box containing test soil is provided. The model box is rectangular and has a first side wall and a second side wall that are opposite to each other in a first direction. The model box has multiple mounting positions that are spaced apart along the first direction. An movable baffle is installed inside the model box and extends vertically to simulate the retaining structure of the foundation pit. A fixed baffle is disposed inside the model box and extends in the vertical direction, and is spaced apart from the movable baffle in the first direction. The fixed baffle is disposed on the side of the movable baffle away from the first side wall, and is detachably connected to the model box corresponding to one of the plurality of mounting positions, for controlling the limited soil width. An adjustable internal support assembly includes a plurality of internal support units spaced apart along the vertical direction. Each internal support unit includes a plurality of internal support structures spaced apart along a second direction. One end of each internal support structure is connected to the first sidewall, and the other end is connected to the movable baffle. The pressure applied by the internal support structure to the movable baffle is adjustable. The monitoring component includes multiple first strain gauges, multiple second strain gauges, multiple dial gauges, and multiple earth pressure cells. The multiple first strain gauges are respectively disposed on both sides of the movable baffle in the first direction for monitoring the horizontal displacement of the movable baffle. The multiple second strain gauges are respectively disposed on the multiple internal support structures for monitoring the axial force of the internal support structures. The multiple dial gauges are disposed on the upper surface of the test soil located between the movable baffle and the fixed baffle, and are distributed at intervals along the first direction for monitoring the vertical displacement of the test soil. The earth pressure cells are embedded in the test soil located between the movable baffle and the fixed baffle for monitoring earth pressure. Among them, the first direction, the second direction, and the up and down directions are perpendicular to each other.

2. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The internal support structure includes a support rod and a screw jack. The support rod extends along the first direction and has a first connecting end and a second connecting end. The first connecting end is connected to the movable baffle. The base of the screw jack is connected to the first side wall, and the top seat of the screw jack is connected to the second connecting end of the support rod, for driving the support rod to move along the first direction.

3. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The model box includes a box frame, a bottom plate, a first side plate, a second side plate, and two tempered glass plates. The box frame is rectangular in shape. The bottom plate is installed at the bottom of the box frame. The first side plate and the second side plate are respectively located on both sides of the box frame in a first direction to form the first side wall and the second side wall. The two tempered glass plates are installed on both sides of the box frame in a second direction. The housing frame has multiple mounting holes in the first direction to form multiple mounting positions, and the fixing baffle is threadedly connected to the housing frame with bolts corresponding to one of the mounting holes.

4. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The distance between any two adjacent mounting positions in the plurality of mounting positions is set to 0.1H, and the distance between the mounting position closest to the second sidewall and the second sidewall is set to... 0.1H, where H is the excavation depth of the foundation pit.

5. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The spacing between any two adjacent internal support units in the plurality of internal support units is set to 0.2H, and the spacing between the internal support unit furthest from the bottom of the model box and the surface of the foundation pit is set to 0.2H, where H is the excavation depth of the foundation pit.

6. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The first strain gauges on both sides of the movable baffle in the first direction are arranged corresponding to the centerline of the movable baffle; In the plurality of first strain gauges spaced apart in the vertical direction, the spacing between any two adjacent first strain gauges is set to 0.25H, and the upper end of the movable baffle is provided with a first strain gauge on each side in the first direction, wherein H is the excavation depth of the foundation pit.

7. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The spacing between any two adjacent dial gauges in the plurality of dial gauges is set to 0.1H, and the spacing between the dial gauges closest to the movable baffle and the movable baffle is set to 0.1H, where H is the excavation depth of the foundation pit.

8. The finite earth pressure model test apparatus as described in claim 1, characterized in that, Each of the aforementioned earth pressure cells is positioned corresponding to the centerline of the movable baffle; In the plurality of earth pressure cells that are spaced apart in the vertical direction, the distance between any two adjacent earth pressure cells is set to 0.25H, and the distance between the earth pressure cell at the top and the top of the movable baffle is set to 0.125H, where H is the excavation depth of the foundation pit.

9. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The test soil was prepared by mixing silt, barite powder, bentonite, double-flying powder and talc powder.

10. The finite earth pressure model test apparatus as described in claim 1, characterized in that, The movable baffle is made of aluminum alloy plate; The fixed baffle is made of steel plate.

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