Adjustable inner support device and foundation pit model test device

Abstract

This utility model discloses an adjustable internal support device and a foundation pit model test device. The foundation pit model test device includes a model box and a baffle plate disposed inside the model box. The adjustable internal support device includes multiple internal support groups spaced apart along the vertical direction. Each internal support group includes multiple internal support units spaced apart along a second direction. Each internal support unit includes a support rod, a strain gauge, and an adjusting component. The first end of the support rod is detachably connected to the baffle plate. The strain gauge is disposed on the support rod. The adjusting component is disposed on the side of the support rod away from the baffle plate, and one end of the adjusting component is detachably connected to the support side wall of the model box, and the other end is detachably connected to the second end of the support rod. The adjusting component can act on the support rod along the second direction. In this way, the support length and / or support axial force of the internal support unit can be adjusted to simulate working conditions such as temperature changes or active loading. The internal components of the internal support unit can be disassembled and reused repeatedly, realizing layered excavation support.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit testing technology, specifically to an adjustable internal support device and a foundation pit model testing device. Background Technology

[0002] With the rapid development of urban underground space development and utilization, deep foundation pit engineering has become an important research direction in the field of geotechnical engineering. To ensure the safety of deep foundation pit construction, a support system combining internal bracing and retaining structures is commonly used in engineering practice. Currently, scaled-down model testing is the main method for studying the foundation pit excavation process. However, current foundation pit model testing has the following technical limitations: 1. Defects in installation method: Before the test, the internal bracing and baffle need to be welded and fixed and pre-embedded in the soil. This one-time installation method results in the inability to reuse the support components, which increases the test cost and wastes materials; 2. Distortion in stress simulation: During the layered excavation process, all pre-embedded supports will be stressed simultaneously, which does not conform to the gradual stress characteristics of "excavation and support as needed" in actual engineering; 3. Lack of adjustment function: Existing internal bracing cannot dynamically adjust its length during the test, making it difficult to simulate working conditions such as temperature changes or active loading. Utility Model Content

[0003] The main purpose of this invention is to propose an adjustable internal support device and a foundation pit model test device to solve the above-mentioned problems.

[0004] To achieve the above objectives, this utility model proposes an adjustable internal support device for use in a foundation pit model testing device. The foundation pit model testing device includes a model box and a baffle disposed within the model box. The baffle extends vertically. The adjustable internal support device includes multiple internal support groups spaced apart along the vertical direction. Each internal support group includes multiple internal support units spaced apart along a first direction. Each internal support unit includes:

[0005] A support rod extends along a second direction and has a first end and a second end, wherein the first end of the support rod is detachably connected to the baffle.

[0006] A strain gauge, disposed on the support rod, is used to monitor the axial force of the support rod on the baffle; and,

[0007] An adjusting member is provided on the side of the support rod away from the baffle, and one end of the member is detachably connected to the support side wall of the model box near the adjusting member in the second direction, and the other end is detachably connected to the second end of the support rod. The adjusting member can act on the support rod in the second direction to adjust the position of the support rod in the second direction and / or the axial force of the support rod on the baffle.

[0008] Wherein, the first direction, the second direction, and the up and down directions are perpendicular to each other.

[0009] Optionally, the adjusting component is a screw jack, the base of which is detachably connected to the supporting side wall of the model box, and the top seat of which is detachably connected to the second end of the support rod.

[0010] Optionally, the inner support unit further includes a fixing rod that extends along the second direction, with one end connected to the top seat of the screw jack and the other end connected to the second end of the support rod.

[0011] Optionally, one end of the fixing rod is welded to the top seat of the screw jack, and the other end of the fixing rod is threaded to the second end of the support rod.

[0012] Optionally, the inner support unit further includes a mounting plate and a first bolt, the mounting plate being welded to the base of the screw jack and threadedly connected to the support side wall of the model box via the first bolt.

[0013] Optionally, the inner support unit further includes a screw rod extending along the second direction, having a first connecting end and a second connecting end, wherein the first connecting end is threadedly connected to a first end of the support rod, and the second connecting end is threadedly connected to the baffle.

[0014] Optionally, the first connecting end of the screw has a first internal threaded hole through it in the vertical direction, and the first end of the support rod has a first connecting hole through it in the vertical direction and a second connecting hole through it in the second direction.

[0015] The inner support unit also includes a second bolt. When the first connecting end of the screw is inserted into the support rod through the second connecting hole, and the first internal thread hole corresponds to the first connecting hole, the second bolt is inserted into the first internal thread hole through the first connecting hole and threadedly connected to the screw.

[0016] Optionally, the second connecting end of the screw has a second internal thread hole extending through it along the second direction;

[0017] The inner support unit further includes a third bolt, which is used to be inserted sequentially into the screw hole and the second internal thread hole of the baffle along the second direction, so as to be threadedly connected to the baffle and the second connecting end of the screw.

[0018] Optionally, the support rod is an aluminum alloy rod.

[0019] This utility model also provides a foundation pit model testing device, the foundation pit model testing device comprising:

[0020] Model box;

[0021] A baffle is provided inside the model box and extends in the vertical direction. The position of the baffle in the second direction is adjustable.

[0022] A sensor, disposed on the baffle, is used to monitor the horizontal displacement and bending moment of the baffle; and,

[0023] An adjustable internal support device is provided inside the model box and is detachably connected to the support side wall of the model box near the adjustment member in the second direction and the baffle.

[0024] The adjustable inner support device includes multiple inner support groups spaced apart along the vertical direction, each inner support group includes multiple inner support units spaced apart along a first direction, and each inner support unit includes:

[0025] A support rod extends along the second direction and has a first end and a second end, wherein the first end of the support rod is detachably connected to the baffle.

[0026] A strain gauge, disposed on the support rod, is used to monitor the axial force of the support rod on the baffle; and,

[0027] An adjusting member is provided on the side of the support rod away from the baffle, and one end of the member is detachably connected to the support side wall of the model box near the adjusting member in the second direction, and the other end is detachably connected to the second end of the support rod. The adjusting member can act on the support rod in the second direction to adjust the position of the support rod in the second direction and / or the axial force of the support rod on the baffle.

[0028] Wherein, the first direction, the second direction, and the up and down directions are perpendicular to each other.

[0029] In the technical solution of this utility model, the position of the support rod in the second direction and / or the pressure of the support rod on the baffle can be adjusted by the action of the adjusting member on the support rod. That is, by changing the position of the support rod, the overall support length of the inner support unit is changed, and by changing the force exerted by the adjusting member on the support rod, the pressure of the support rod on the baffle is changed. In this way, the support length of the inner support unit and / or the axial force of the inner support unit on the baffle can be adjusted to simulate working conditions such as temperature changes or active loading. Furthermore, the support rod is detachably connected to the baffle and the adjusting member, allowing for the replacement of supports of different sizes. The rod allows for model tests with various internal support stiffnesses, saving materials. Furthermore, the adjustable component is detachably connected to the support sidewall of the model box, enabling modular assembly of the internal support unit. Each component within the internal support unit can be disassembled and reused repeatedly, enhancing its practicality. Simultaneously, multiple internal support units spaced apart along the second direction form an internal support group, and multiple internal support groups spaced apart along the vertical direction form an adjustable internal support device. This allows for layered excavation and support during foundation pit model tests, more accurately reflecting the actual construction process of foundation pits in engineering, and overcoming the problem of existing support structures requiring connection and pre-embedding with baffles before testing. Attached Figure Description

[0030] 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.

[0031] Figure 1 A schematic diagram of a structure of an embodiment of the foundation pit model test device provided by this utility model;

[0032] Figure 2 for Figure 1 A partial structural schematic diagram of the foundation pit model test device;

[0033] Figure 3 for Figure 1 Side view of the model box of the foundation pit model test device.

[0034] Explanation of icon numbers:

[0035]

[0036] 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

[0037] 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.

[0038] 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.

[0039] 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.

[0040] With the rapid development of urban underground space development and utilization, deep foundation pit engineering has become an important research direction in the field of geotechnical engineering. To ensure the safety of deep foundation pit construction, a support system combining internal bracing and retaining structures is commonly used in engineering practice. Currently, scaled-down model testing is the main method for studying the foundation pit excavation process. However, current foundation pit model testing has the following technical limitations: 1. Defects in installation method: Before the test, the internal bracing and baffle need to be welded and fixed and pre-embedded in the soil. This one-time installation method results in the inability to reuse the support components, which increases the test cost and wastes materials; 2. Distortion in stress simulation: During the layered excavation process, all pre-embedded supports will be stressed simultaneously, which does not conform to the gradual stress characteristics of "excavation and support as needed" in actual engineering; 3. Lack of adjustment function: Existing internal bracing cannot dynamically adjust its length during the test, making it difficult to simulate working conditions such as temperature changes or active loading.

[0041] In view of this, the present invention provides an adjustable internal support device 100 for use in a foundation pit model test device 1000, the foundation pit model test device 1000 including a model box 200 and a baffle 300 disposed inside the model box 200, the baffle 300 extending in the vertical direction. Figures 1 to 3 An embodiment of the foundation pit model test device 1000 provided by this utility model.

[0042] Please see Figure 1 and Figure 2 The adjustable internal support device 100 includes a plurality of internal support groups spaced apart along the vertical direction. Each internal support group includes a plurality of internal support units 1 spaced apart along a first direction. Each internal support unit 1 includes a support rod 11, a strain gauge 12, and an adjusting member 13. The support rod 11 extends along a second direction and has a first end and a second end. The first end of the support rod 11 is detachably connected to the baffle 300. The strain gauge 12 is disposed on the support rod 11 and is used to monitor the axial force of the support rod 11 on the baffle 300. The adjusting member 13 is located on the side of the support rod 11 away from the baffle 300, and one end of it is detachably connected to the support side wall 210 of the model box 200 near the adjusting member 13 in the second direction, and the other end of it is detachably connected to the second end of the support rod 11. The adjusting member 13 can act on the support rod 11 in the second direction to adjust the position of the support rod 11 in the second direction and / or the pressure of the support rod 11 on the baffle 300; wherein, the second direction is perpendicular to the up and down direction.

[0043] In this utility model's technical solution, the support rod 11 can be adjusted by the adjusting member 13, thereby adjusting the position of the support rod 11 in the second direction and / or the pressure of the support rod 11 on the baffle 300. That is, by changing the position of the support rod 11, the overall support length of the inner support unit 1 is changed, and by changing the force exerted by the adjusting member 13 on the support rod 11, the pressure of the support rod 11 on the baffle 300 is changed. Thus, the support length of the inner support unit 1 and / or the support axial force of the inner support unit 1 on the baffle 300 are adjustable, simulating working conditions such as temperature changes or active loading. Furthermore, the support rod 11 is detachably connected to the baffle 300 and the adjusting member 13, enabling more... Different sizes of support rods 11 can be used to conduct model tests with various internal support stiffnesses, saving materials. Furthermore, the adjusting component 13 is detachably connected to the support sidewall 210 of the model box 200, realizing the modular assembly of the internal support unit 1. The components within the internal support unit 1 can be disassembled and reused repeatedly, making it highly practical. At the same time, multiple internal support units 1 distributed at intervals along the second direction form an internal support group. Multiple internal support groups are distributed at intervals along the vertical direction to form the adjustable internal support device 100, which can realize layered excavation and support in the foundation pit model test. This can more accurately reflect the construction process of the foundation pit in actual engineering and overcome the problem that the existing support structure needs to be connected and pre-embedded with the baffle 300 before the test.

[0044] It should be noted that in this invention, the adjusting component 13 can be an electric push rod or a jack, etc., which can adjust the supporting axial force of the support rod on the baffle in real time according to the monitoring results of the strain gauge. More specifically, the adjustable internal support device 100 also includes a control terminal, which is electrically connected to the adjusting component 13 and the strain gauge 12 via wireless / wired means. The control terminal can be a computer, mobile phone terminal, etc.

[0045] For details, please refer to Figure 1 and Figure 2 In one embodiment of this utility model, the adjusting member 13 is a screw jack, the base of the screw jack is detachably connected to the support side wall 210 of the model box 200, and the top seat of the screw jack is detachably connected to the second end of the support rod 11.

[0046] Thus, by moving the lifting sleeve of the screw jack, the support rod 11 can be driven to move along the second direction, changing the position of the support rod 11, thereby making the support length of the inner support unit 1 adjustable. Furthermore, the movement of the lifting sleeve of the screw jack can also adjust the magnitude of the force it applies to the support rod 11, thereby making the support axial force of the inner support unit 1 on the baffle 300 adjustable.

[0047] For further details, please refer to Figure 1 and Figure 2 The inner support unit 1 also includes a fixing rod 14, which extends along the second direction. One end of the fixing rod 14 is connected to the top seat of the screw jack, and the other end is connected to the second end of the support rod 11.

[0048] Furthermore, the connection between the fixing rod 14 and the spiral jack and the support rod 11 can be a threaded connection or a snap-fit ​​connection, etc.

[0049] More specifically, in one embodiment of this utility model, one end of the fixing rod 14 is welded to the top seat of the screw jack, and the other end of the fixing rod 14 is threadedly connected to the second end of the support rod 11. More specifically, the second end of the support rod 11 has a first mounting hole extending along the vertical direction and a second mounting hole extending along the second direction. The other end of the fixing rod 14 has a threaded hole extending along the vertical direction. The inner support unit 1 also includes a connecting bolt. The other end of the fixing rod 14 is inserted into the support rod 11 through the second mounting hole, and the threaded hole corresponds to the first mounting hole. The connecting bolt is sequentially inserted into the first mounting hole and the threaded hole along the vertical direction and is threadedly connected to the fixing rod 14, thereby achieving a stable connection between the fixing rod 14 and the support rod.

[0050] For details, please refer to Figure 1 and Figure 2 The inner support unit 1 also includes a mounting plate 15 and a first bolt 16. The mounting plate 15 is welded to the base of the spiral jack and is threadedly connected to the support side wall 210 of the model box 200 through the first bolt 16.

[0051] For details, please refer to Figure 1 and Figure 2 The inner support unit 1 further includes a screw 17, which extends along the second direction and has a first connecting end and a second connecting end. The first connecting end is threadedly connected to the first end of the support rod 11, and the second connecting end is threadedly connected to the baffle 300.

[0052] For further details, please refer to Figure 1 and Figure 2The first connecting end of the screw 17 has a first internal threaded hole extending along the vertical direction, and the first end of the support rod 11 has a first connecting hole extending along the vertical direction and a second connecting hole extending along the second direction. The inner support unit 1 also includes a second bolt 18. When the first connecting end of the screw 17 is inserted into the support rod 11 through the second connecting hole, and the first internal threaded hole corresponds to the first connecting hole, the second bolt 18 is inserted into the first internal threaded hole through the first connecting hole and threadedly connected to the screw 17. In this way, the screw 17 and the support rod 11 are firmly and stably connected.

[0053] For further details, please refer to Figure 1 and Figure 2 The second connecting end of the screw 17 has a second internal threaded hole extending along the second direction; the inner support unit 1 also includes a third bolt 19, which is used to be sequentially inserted into the screw hole and the second internal threaded hole of the baffle 300 along the second direction to achieve a threaded connection with the baffle 300 and the second connecting end of the screw 17. Thus, the connection between the screw 17 and the baffle 300 is firm and stable.

[0054] Furthermore, the inner support unit 1 is tightly connected to the baffle 300, which can reduce the risk of the inner support unit 1 becoming loose and falling off during the test and improve the reliability of the adjustable inner support device 100.

[0055] Specifically, in one embodiment of this utility model, the support rod 11 is an aluminum alloy rod.

[0056] This utility model also provides a foundation pit model test device 1000, please refer to [link / reference]. Figures 1 to 3 The foundation pit model test device 1000 includes a model box 200, a baffle 300, a sensor, and an adjustable internal support device 100. The baffle 300 is disposed inside the model box 200 and extends in the vertical direction. The position of the baffle 300 in the second direction is adjustable. The sensor is disposed on the baffle 300 and is used to monitor the horizontal displacement and bending moment of the baffle 300. The adjustable internal support device 100 is disposed inside the model box 200 and is detachably connected to the support side wall 210 of the model box 200 near the adjusting member 13 in the second direction and the baffle 300.

[0057] It should be noted that the adjustable inner support device 100 adopts the adjustable inner support device 100 as described above. That is, the foundation pit model test device 1000 has all the technical features of all embodiments of the adjustable inner support device 100 described above, and thus has all the technical effects brought about by all the above technical features. They will not be described in detail here.

[0058] Specifically, in this utility model, the model box 200 is made of multiple side panels spliced ​​together, wherein the two side panels located in the first direction are tempered glass panels, which facilitates observation of soil deformation.

[0059] Specifically, at least two sensors are provided, and the two sensors are located on both sides of the baffle in the second direction and are correspondingly arranged.

[0060] Specifically, the sensor is a strain gauge.

[0061] Specifically, the test method of the foundation pit model test device 1000 includes the following steps:

[0062] Step S1: Determine the dimensions of the support rod 11 and the parameters of the soil based on the actual engineering conditions on site and the similarity ratio of the model test.

[0063] Step S2: Before the test, the mounting plate 15 is welded to the base of the screw jack, the fixing rod 14 is welded to the top seat of the screw jack and threaded to the second end of the support rod 11, and the screw 17 is threaded to the first end of the support rod 11 to form the inner support unit 1.

[0064] Step S3: Fix the strain gauge 12 to the middle of the support rod 11 to measure the support axial force during the test.

[0065] Step S4: Determine the material and size of the baffle 300 based on the model test and the actual engineering conditions on site. The baffle 300 is used to simulate the retaining structure in the actual foundation pit project. Screw the third bolt 19 into the baffle 300.

[0066] Step S5: Construct model box 200, embed baffle 300 and sensor in model box 200, screw first bolt 16 into the support side wall 210 of model box 200 to prevent soil leakage during filling, and then fill soil in layers in model box 200 and compact it.

[0067] Step S6: Excavate the soil to a position below the first inner support unit 1, install the first inner support unit 1, that is, thread the third bolt 19 to the screw rod 17, adjust the lifting sleeve of the spiral jack so that the mounting plate 15 abuts against the support side wall 210 of the model box 200, and use the first bolt 16 to fix the mounting plate 15 to the support side wall 210 of the model box 200.

[0068] Step S7: Install multiple inner support units 1 sequentially along the first direction according to step S6 to form an inner support group. Then install multiple inner support groups sequentially from bottom to top until the foundation pit excavation is completed. After each inner support group is completed, let it stand for one hour before taking sensor readings.

[0069] Step S8: Adjust each of the spiral jacks according to the test plan to adjust the support length or support axial force of each inner support unit 1.

[0070] 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. An adjustable inner support device used in a foundation pit model test device, the foundation pit model test device including a model box and a baffle provided in the model box, the baffle being provided extending in an up-and-down direction, characterized in that, The adjustable internal support device includes a plurality of internal support groups spaced apart along the vertical direction, each internal support group including a plurality of internal support units spaced apart along a first direction, and each internal support unit including: A support rod extends along a second direction and has a first end and a second end, wherein the first end of the support rod is detachably connected to the baffle. A strain gauge, disposed on the support rod, is used to monitor the axial force of the support rod on the baffle; and, An adjusting member is provided on the side of the support rod away from the baffle, and one end of the member is detachably connected to the support side wall of the model box near the adjusting member in the second direction, and the other end is detachably connected to the second end of the support rod. The adjusting member can act on the support rod in the second direction to adjust the position of the support rod in the second direction and / or the axial force of the support rod on the baffle. Wherein, the first direction, the second direction, and the up and down directions are perpendicular to each other.

2. The adjustable internal support device as described in claim 1, characterized in that, The adjusting component is a screw jack, the base of which is detachably connected to the supporting side wall of the model box, and the top seat of which is detachably connected to the second end of the support rod.

3. The adjustable internal support device as described in claim 2, characterized in that, The inner support unit also includes a fixing rod that extends along the second direction, with one end connected to the top seat of the screw jack and the other end connected to the second end of the support rod.

4. The adjustable internal support device as described in claim 3, characterized in that, One end of the fixing rod is welded to the top seat of the screw jack, and the other end of the fixing rod is threaded to the second end of the support rod.

5. The adjustable internal support device as described in claim 2, characterized in that, The inner support unit also includes a mounting plate and a first bolt. The mounting plate is welded to the base of the spiral jack and is threadedly connected to the support side wall of the model box through the first bolt.

6. The adjustable internal support device as described in claim 2, characterized in that, The inner support unit further includes a screw rod extending along the second direction, having a first connecting end and a second connecting end. The first connecting end is threadedly connected to a first end of the support rod, and the second connecting end is threadedly connected to the baffle.

7. The adjustable internal support device as described in claim 6, characterized in that, The first connecting end of the screw has a first internal threaded hole through it in the vertical direction, and the first end of the support rod has a first connecting hole through it in the vertical direction and a second connecting hole through it in the second direction. The inner support unit also includes a second bolt. When the first connecting end of the screw is inserted into the support rod through the second connecting hole, and the first internal thread hole corresponds to the first connecting hole, the second bolt is inserted into the first internal thread hole through the first connecting hole and threadedly connected to the screw.

8. The adjustable internal support device as described in claim 7, characterized in that, The second connecting end of the screw has a second internal thread hole extending through it along the second direction; The inner support unit further includes a third bolt, which is used to be inserted sequentially into the screw hole and the second internal thread hole of the baffle along the second direction, so as to be threadedly connected to the baffle and the second connecting end of the screw.

9. The adjustable internal support device as described in claim 1, characterized in that, The support rod is an aluminum alloy rod.

10. A foundation pit model test device, characterized in that, The foundation pit model test device includes: Model box; A baffle is provided inside the model box and extends in the vertical direction. The position of the baffle in the second direction is adjustable. A sensor, disposed on the baffle, is used to monitor the horizontal displacement and bending moment of the baffle; and, The adjustable internal support device as described in any one of claims 1-9 is disposed inside the model box and is detachably connected to the support side wall of the model box near the adjusting member in the second direction and the baffle.

Images