In-situ detection device for deformation modulus of subgrade soil

Abstract

The utility model belongs to the roadbed soil body deformation modulus detection technical field relates to a kind of roadbed soil body deformation modulus in-situ detection device.The device includes bearing plate, jack, support frame, contact arm;Bearing plate bottom surface is crimped on the roadbed to be measured, and the top surface is protruded with force column, and strain gauge is pasted on the lateral wall of force column;The force end of jack is contacted with the top end of force column, to load and unload to bearing plate by force column;Support frame is set on the flat ground outside the roadbed to be measured not to be disturbed;Contact arm is across above support frame, and contact arm middle part is rotatably connected with support frame, and contact arm one end is equipped with measuring head, and measuring head is pressed on the top surface of bearing plate, and other end is equipped with micrometer;When jack loads and unloads to bearing plate, the settlement of bearing plate is obtained using micrometer, and the normal average stress of bearing plate is obtained using strain gauge.The utility model realizes the in-situ detection of the deformation modulus of the roadbed soil body to be measured under actual construction scene, and improves detection accuracy.

Description

Technical Field

[0001] This utility model belongs to the field of roadbed soil deformation modulus detection technology, specifically relating to an in-situ detection device for roadbed soil deformation modulus. Background Technology

[0002] Testing the deformation modulus of subgrade soil is a crucial step in assessing the bearing capacity, stability, and post-construction settlement of the subgrade. Currently, soil deformation modulus testing is primarily conducted in laboratories. Soil samples taken from the construction site are placed in a test container, and loading equipment such as pressure plates is used to apply pressure to the samples. The settlement is then observed, and the soil deformation modulus is calculated.

[0003] However, since roadbed construction is mostly carried out in open-air environments, the environmental factors and construction techniques during actual construction will directly affect or change the soil properties. Indoor tests cannot truly simulate the complex construction environment on site, and the soil samples cannot fully represent the actual roadbed soil conditions. Therefore, the test results obtained from indoor tests cannot accurately reflect the actual deformation modulus of the roadbed soil. Only by conducting on-site in-situ testing of the deformation modulus of the roadbed soil in the actual construction scenario of roadbed engineering can the bearing capacity and stability of the roadbed be accurately assessed.

[0004] In view of this, it is necessary to develop an in-situ testing device for the deformation modulus of roadbed soil to meet the needs of in-situ testing. Utility Model Content

[0005] In view of the shortcomings of the related technologies, this utility model provides an in-situ detection device for the deformation modulus of roadbed soil to solve the technical problems mentioned in the background art.

[0006] This utility model provides an in-situ testing device for the deformation modulus of roadbed soil, comprising: The bearing plate has its bottom surface pressed against the roadbed to be tested, and a force transmission column protrudes from its top surface. Strain gauges are attached to the side walls of the force transmission column. The jack has its force-applying end in contact with the top of the force-transmitting column, so as to load and unload the load onto the bearing plate through the force-transmitting column. The support frame is set on a flat, undisturbed surface outside the roadbed to be tested; The connecting arm extends horizontally above the support frame, and its middle part is rotatably connected to the support frame; one end of the connecting arm is equipped with a probe, which presses against the top surface of the bearing plate, and the other end of the connecting arm is equipped with a dial indicator. When the jack loads and unloads the bearing plate through the force transmission column, the settlement of the bearing plate is obtained by dial gauge and the normal average stress of the bearing plate is obtained by strain gauge.

[0007] In some embodiments, the force transmission column is vertically connected to the center of the top surface of the bearing plate. The force transmission column includes a core and a cylinder that are interconnected and coaxially arranged. The cylinder is connected between the bearing plate and the core. The strain gauge is attached to the side wall of the core. The side wall of the cylinder has a detection window that communicates with the inner cavity of the cylinder. The probe at one end of the connecting arm extends into the inner cavity of the cylinder through the detection window and presses against the center of the top surface of the bearing plate.

[0008] In some embodiments, the in-situ detection device for the deformation modulus of subgrade soil further includes a limiting frame, which is disposed on the side of the support frame away from the subgrade to be tested; the limiting frame includes two columns arranged opposite each other and two limiting rods connected between the two columns and arranged opposite each other vertically; the end of the connecting arm away from the subgrade to be tested extends into the space between the two limiting rods.

[0009] In some embodiments, the limiting frame further includes a limiting post disposed between two columns, the limiting post being connected to two limiting rods; the connecting arm includes a first straight arm, a second straight arm, and a bent arm connected in sequence, the end of the first straight arm near the second straight arm being rotatably connected to the support frame, the first straight arm including two parallel supporting arms and a connecting arm connecting the same end of the two supporting arms, the two supporting arms extending between the limiting post and the two columns respectively, the connecting arm being located on the side of the limiting post away from the support frame, and a dial indicator being connected between the two supporting arms; the bent arm includes a vertical arm and a horizontal arm, the upper end of the vertical arm being connected to the end of the second straight arm away from the first straight arm, one end of the horizontal arm being connected to the lower end of the vertical arm, and the other end of the horizontal arm extending through the detection window into the inner cavity of the column, and that end being provided with a probe.

[0010] In some embodiments, the support frame includes two support columns arranged opposite each other, a support rod connected between the two support columns, two supports spaced apart along the length of the support rod, and a connecting arm clamped between the two supports; the supports have rotating holes, and a rotating shaft passes through the connecting arm, which is inserted into the rotating holes of the two supports so that the connecting arm is rotatably connected to the support frame.

[0011] In some embodiments, the ratio of the horizontal distance between the pivot point of the connecting arm on the support frame and the probe to its horizontal distance to the dial indicator is not greater than 2.

[0012] In some embodiments, the in-situ testing device for the deformation modulus of subgrade soil also includes a chassis, which is detachably connected to the bottom surface of the bearing plate and pressed against the subgrade to be tested; the chassis and the bearing plate are coaxially arranged, and the diameter of the chassis is larger than the diameter of the bearing plate.

[0013] In some embodiments, a pin is provided between the chassis and the support plate; the chassis is detachably connected to the support plate by a plurality of connectors, the connectors including a fixing plate, a clamping plate, and a connecting plate connected between the fixing plate and the clamping plate, the fixing plate is detachably connected to the top surface of the chassis by bolts, and the bottom surface of the clamping plate is pressed against the top surface of the support plate.

[0014] In some embodiments, a level is provided on the top surface of the support plate.

[0015] In some embodiments, multiple handles are provided on the top surface of the support plate and the top surface of the connecting arm.

[0016] Based on the above technical solution, the in-situ detection device for the deformation modulus of subgrade soil in this utility model embodiment can accurately obtain the settlement of the bearing plate by setting up a support frame and connecting arm, as well as setting up probes and dial gauges at both ends of the connecting arm. This realizes the in-situ detection of the deformation modulus of the subgrade soil to be tested in actual construction scenarios, without the need for soil sampling, avoiding soil disturbance, making the test results more accurate, and thus enabling a real and accurate assessment of the bearing capacity and stability of the subgrade to be tested. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the in-situ detection device for the deformation modulus of roadbed soil according to the present invention. Figure 2 This is a front view of the in-situ detection device for the deformation modulus of roadbed soil of this utility model (the handle on the bearing plate is not shown). Figure 3 This is a schematic diagram of the bearing plate, force transmission column and chassis in the in-situ testing device for the deformation modulus of roadbed soil of this utility model.

[0018] In the diagram: 1. Bearing plate; 2. Force transmission column; 21. Column core; 22. Column tube; 221. Detection window; 3. Support frame; 31. Support column; 32. Support rod; 33. Support; 4. Connecting arm; 41. First straight arm; 411. Support arm; 412. Connecting arm; 42. Second straight arm; 43. Bending arm; 431. Vertical arm; 432. Horizontal arm; 44. Rotating shaft; 45. Connecting block; 51. Probe; 52. Dial indicator; 53. Handle; 6. Limiting frame; 61. Column; 62. Limiting rod; 63. Limiting column; 7. Chassis; 8. Connecting piece; 81. Fixing plate; 82. Clamping plate; 83. Connecting plate. Detailed Implementation

[0019] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0020] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "top", "bottom", "inner", "outer", "left", "right", "front", "rear", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] refer to Figures 1-2 As shown, this utility model provides an in-situ testing device for the deformation modulus of subgrade soil, used for on-site in-situ testing of the deformation modulus of the subgrade soil to be tested in actual construction scenarios of subgrade engineering. The device includes a bearing plate 1, a jack, a support frame 3, and a connecting arm 4.

[0024] The bearing plate 1 can be made of S355 grade steel, with a diameter of 300mm and a thickness of 25mm, but the material and size of the bearing plate 1 are not limited to these. The bottom surface of the bearing plate 1 is pressed onto the roadbed to be tested, and a force transmission column 2 is protruding from the top surface of the bearing plate 1. Strain gauges (not shown) are attached to the side walls of the force transmission column 2.

[0025] The force-applying end of the jack (not shown) contacts the top of the force transmission column 2, and the jack loads and unloads the load on the bearing plate 1 via the force transmission column 2. Further, the base of the jack is fixed to a reaction device located above the bearing plate 1 and the force transmission column 2. The reaction device provides a reliable foundation for the jack to prevent it from tilting or tipping over. The reaction device takes many forms and is a common device in the industry; no specific limitation is made here. Specifically, the jack can be a hydraulic jack, connected to a hydraulic pump via a high-pressure hose. The hydraulic pump drives the jack to load and unload the load on the bearing plate 1.

[0026] The support frame 3 is set on a flat, undisturbed surface outside the roadbed to be tested, so that the state of the support frame 3 is not affected by the deformation of the roadbed soil.

[0027] The connecting arm 4 extends horizontally above the support frame 3, and its middle part is rotatably connected to the support frame 3. One end of the connecting arm 4 is equipped with a probe 51, which presses against the top surface of the bearing plate 1. The other end of the connecting arm 4 is equipped with a dial indicator 52, or a displacement sensor can be used instead of the dial indicator 52.

[0028] When the jack loads and unloads the load onto the bearing plate 1 via the force transmission column 2, the strain gauge attached to the force transmission column 2 measures the stress on the force transmission column 2, thereby calculating the load applied to the bearing plate 1, and then calculating the normal average stress of the bearing plate 1. At the same time, the bearing plate 1 transfers the load to the soil of the roadbed to be tested, causing the soil of the roadbed to be tested to deform, and the bearing plate 1 settles accordingly. Since the connecting arm 4 is supported by the support frame 3, and the support frame 3 is located on an undisturbed flat ground, the connection position of the connecting arm 4 on the support frame 3 is not affected by the deformation of the soil of the roadbed to be tested. The height position of the probe 51 at one end of the connecting arm 4 changes only with the settlement of the bearing plate 1, causing the connecting arm 4 to rotate around the support frame 3, thereby causing the reading of the dial gauge 52 at the other end of the connecting arm 4 to change. By combining the reading of the dial gauge 52 with the structural dimensions of the connecting arm 4 itself, the change in height at the end of the probe 51 is calculated, that is, the settlement of the bearing plate 1 is obtained. To further explain, when testing the deformation modulus of the subgrade soil, the bearing plate 1 is gradually loaded to draw a loading-settlement curve, and then the deformation modulus of the subgrade soil can be calculated.

[0029] In the above illustrative embodiment, by setting up the support frame 3 and the connecting arm 4, as well as the probes 51 and dial gauges 52 at both ends of the connecting arm 4, the reading of the dial gauge 52 is not affected by the deformation of the subgrade soil to be tested, thereby accurately obtaining the settlement of the bearing plate 1. It also realizes the in-situ detection of the deformation modulus of the subgrade soil to be tested in actual construction scenarios, improving the detection accuracy, and thus enabling a real and accurate assessment of the bearing capacity and stability of the subgrade to be tested.

[0030] refer to Figures 1-2 As shown, in some embodiments, the force transmission column 2 is vertically connected to the center of the top surface of the bearing plate 1; the force transmission column 2 includes a core 21 and a cylinder 22 that are interconnected and coaxially arranged, with the cylinder 22 connecting the bearing plate 1 and the core 21; the core 21 is a solid cylindrical structure, and the cylinder 22 has an internal cavity. Strain gauges are attached to the side wall of the core 21. A detection window 221 communicating with the inner cavity of the cylinder 22 is provided on the side wall of the cylinder 22; a probe 51 at one end of the connecting arm 4 extends into the inner cavity of the cylinder 22 through the detection window 221, and the probe 51 presses against the center of the top surface of the bearing plate 1. This illustrative embodiment, through the setting of the detection window 221 on the force transmission column 2, enables the detection of the settlement at the center position of the bearing plate 1.

[0031] refer to Figures 1-2 As shown, in some embodiments, the in-situ testing device for the deformation modulus of subgrade soil further includes a limiting frame 6, which is disposed on the side of the support frame 3 away from the subgrade to be tested. The limiting frame 6 includes two opposing columns 61 and two limiting rods 62 connected between the two columns 61 and arranged vertically opposite each other. The end of the connecting arm 4 away from the subgrade to be tested extends between the two limiting rods 62. When the connecting arm 4 rotates around the support frame 3, the two limiting rods 62 on the limiting frame 6 limit the vertical rotation angle range of the connecting arm 4. Furthermore, the connection height of each limiting rod 62 on the two columns 61 is adjustable to flexibly adjust the vertical rotation angle range of the connecting arm 4 according to actual needs.

[0032] refer to Figures 1-2As shown, in some embodiments, the limiting frame 6 further includes a limiting post 63 disposed between the two uprights 61, and the limiting post 63 is connected to the two limiting rods 62. The connecting arm 4 includes a first straight arm 41, a second straight arm 42, and a bent arm 43 connected in sequence; the end of the first straight arm 41 near the second straight arm 42 is rotatably connected to the support frame 3, and the first straight arm 41 includes two parallel support arms 411 and a connecting arm 412 connecting the same end of the two support arms 411, so that the first straight arm 41 is in the shape of a c; the two support arms 411 extend between the limiting post 63 and the two uprights 61 respectively, and the connecting arm 412 is located on the side of the limiting post 63 away from the support frame 3; the arrangement of the two support arms 411 and the limiting post 63 prevents the connecting arm 4 from deflecting on its horizontal plane. A dial indicator 52 is connected between the two support arms 411 and close to the limiting frame 6. One end of the second straight arm 42 is connected to the two support arms 411 of the first straight arm 41 via a connecting block 45, and the other end is connected to the bent arm 43. The bent arm 43 includes a vertical arm 431 and a horizontal arm 432. The upper end of the vertical arm 431 is connected to the end of the second straight arm 42 away from the first straight arm 41, and one end of the horizontal arm 432 is connected to the lower end of the vertical arm 431. The other end of the horizontal arm 432 extends into the inner cavity of the column cylinder 22 through the detection window 221, and is equipped with a probe 51 at this end. This illustrative embodiment refines the structural arrangement of the connecting arm 4, enabling the probe 51 at one end of the connecting arm 4 to reliably press against the center of the top surface of the bearing plate 1, and the other end to achieve rotational limitation between it and the limiting frame 6, ensuring that the connecting arm 4 only rotates up and down in the vertical plane, thereby improving detection accuracy.

[0033] refer to Figures 1-2 As shown, in some embodiments, the support frame 3 includes two opposing support columns 31 and a support rod 32 connected between the two support columns 31. Two supports 33 are spaced apart along the length of the support rod 32, and a connecting arm 4 is clamped between the two supports 33. A rotating hole is provided on each support 33, and a rotating shaft 44 passes through the connecting arm 4. The rotating shaft 44 is inserted into the rotating hole of the two supports 33, so that the connecting arm 4 is rotatably connected to the support frame 3. Furthermore, the connection height of the support rod 32 on the two support columns 31 is adjustable to flexibly adjust the installation height of the connecting arm 4 according to actual needs. This illustrative embodiment refines the rotatable connection structure between the connecting arm 4 and the support frame 3, allowing the connecting arm 4 to be supported on the support frame 3 and to rotate around the support frame 3.

[0034] refer to Figure 2 As shown, in some embodiments, when the overall length direction of the connecting arm 4 is horizontal, the horizontal distance between the rotation point of the connecting arm 4 on the support frame 3 and the probe 51 is... The horizontal distance between the pivot point of the connecting arm 4 on the support frame 3 and the dial indicator 52. The ratio of the two is no greater than 2, that is This refines the dimensional relationship between the two ends of the connecting arm 4 relative to the rotation point of the connecting arm 4, and avoids the dial indicator 52 being too close to the rotation point of the connecting arm 4, which would result in the dial indicator 52 being insufficiently sensitive or accurate in measurement.

[0035] refer to Figure 3 As shown, in some embodiments, the in-situ testing device for the deformation modulus of subgrade soil also includes a chassis 7, which is detachably connected to the bottom surface of the bearing plate 1 and pressed against the subgrade to be tested. The chassis 7 and the bearing plate 1 are coaxially arranged, and the diameter of the chassis 7 is larger than the diameter of the bearing plate 1. Specifically, the chassis 7 can also be made of S355 grade steel, with a diameter of 600 mm and a thickness of 35 mm, but the material and size of the bearing plate 1 are not limited to these. When testing the deformation modulus of the subgrade soil, the use of the chassis 7 can be flexibly selected according to the size of the test area and load requirements, thereby improving the universality of the test.

[0036] refer to Figure 3 As shown, in some embodiments, a pin (not shown) is provided between the chassis 7 and the support plate 1 to achieve assembly positioning between the chassis 7 and the support plate 1. The chassis 7 is detachably connected to the support plate 1 through multiple connectors 8. The connectors 8 include a fixing plate 81, a clamping plate 82, and a connecting plate 83 connecting the fixing plate 81 and the clamping plate 82. The fixing plate 81 is detachably connected to the top surface of the chassis 7 by bolts. The bottom surface of the clamping plate 82 is pressed against the top surface of the support plate 1, thereby conveniently and reliably clamping the support plate 1 onto the chassis 7.

[0037] In some embodiments, a level (not shown) is provided on the top surface of the bearing plate 1 to detect whether the bearing plate 1 is horizontal, that is, to detect whether the force transmission column 2 is vertical, thereby ensuring that the jack applies a vertical load to the force transmission column 2 and the bearing plate 1 to deform the subgrade soil to be tested.

[0038] refer to Figure 1 , Figure 3 As shown, in some embodiments, multiple handles 53 are provided on the top surface of the support plate 1 and the top surface of the connecting arm 4, so as to manually move and place the support plate 1 and the connecting arm 4.

[0039] The following is combined with Figures 1-3 Briefly describe the main steps of in-situ testing of the deformation modulus of roadbed soil using this utility model: 1) Preparation before testing: Use tools (such as a steel ruler or a small shovel) or rotate the bearing plate 1 or the base plate 7 back and forth to level the test area of ​​the subgrade to be tested. Any loose materials should be removed. Assemble the in-situ testing device for the deformation modulus of the subgrade soil and make the bearing plate 1 or the base plate 7 fully contact the surface of the subgrade to be tested. Ensure that the support frame 3 and the limiting frame 6 are stably supported on the undisturbed flat ground outside the subgrade to be tested. Use a level to check whether the top surface of the bearing plate 1 is level. If necessary, spread a thin layer of dry medium-grained sand or gypsum on the surface of the subgrade to be tested and obtain a level bearing plate 1 surface by gently tapping the top surface of the bearing plate 1. Note that when using gypsum as a subbase material, grease should be applied to the bottom of the bearing plate 1. Subsequent testing can only begin after the gypsum has solidified.

[0040] It should be noted that for rapidly dried equigranular sand, or for roadbed soil that has formed a surface crust, softened, or has been disturbed by other factors, subsequent testing should be conducted after the disturbed soil is removed. For fine-grained soil (such as silt or clay), subsequent testing can only be conducted to accurately assess the soil consistency when it changes from hard to firm. If necessary, the consistency of the soil under test can be measured at different depths, up to a depth equal to the diameter of the bearing plate 1 below the ground surface.

[0041] 2) Testing: First, adjust the readings of the strain gauge and dial indicator 52 to zero. Then, perform two loading cycles and one unloading cycle. Specifically, the first loading cycle applies the load in at least six stages, with approximately equal increments, until the maximum normal stress required by the bearing plate 1 is reached. During unloading, the load can be released in four stages, typically including releasing to 50% and 25% of the maximum value, until the load corresponding to the zero reading is reached. During the second loading cycle, the load is increased only to the penultimate stage of the first loading cycle. Each stage of load increase or release is usually completed within one minute. At the end of each loading stage in the second loading cycle, record the average normal stress of the bearing plate 1. Settlement readings from dial gauge 52 .

[0042] 3) Calculate the deformation modulus of the subgrade soil to be measured, including: The settlement at the center of bearing plate 1 is calculated according to equation (1). , (1); The loading-settlement curve was plotted based on the data from the second loading cycle. The equation of this curve is expressed as follows: Then, the coefficients are solved according to equation (2). , , ;in, and These represent the average normal stress of bearing plate 1 and the settlement at the center of bearing plate 1 at the end of each loading stage during the second loading process, respectively. This is the number of loading stages during the second loading. (2); The deformation modulus of the subgrade soil after the second loading is calculated according to equation (3). ,in, This represents the maximum normal average stress of the bearing plate 1 during the second loading. The radius of the bearing plate 1 or chassis 7 that is pressed against the roadbed to be tested; (3).

[0043] To further explain, the in-situ testing device for the deformation modulus of subgrade soil of this invention obtains the deformation modulus of the subgrade soil to be tested through a testing method of loading, unloading, and then loading again. It primarily reflects the residual stiffness of the subgrade soil after compaction or disturbance, more closely resembling the actual stress state of the subgrade after construction compaction and repeated vehicle loading in engineering projects. Furthermore, the load cycles of secondary loading basically cover the possible stress range in actual engineering, such as the repeated vehicle loads in subgrade design, ensuring the deformation modulus. The above-mentioned method for detecting the deformation modulus of subgrade soil can more effectively analyze the deformation properties and bearing capacity of the soil, especially reflecting the actual effect of the dynamic stress generated by vehicles running at high speed on the subgrade. In contrast, the current linear plate load test method in the industry focuses more on the stiffness of the soil in the initial elastic stage and does not adequately reflect the residual deformation characteristics of the soil after repeated loading. Its test results have certain limitations and are restricted by factors such as test range, stress conditions, and soil disturbance, making it difficult to fully represent the overall deformation characteristics of the foundation in actual engineering.

[0044] In summary, the in-situ testing device for the deformation modulus of subgrade soil of this utility model, through the setting of support frame 3 and connecting arm 4, and the setting of probes 51 and dial gauges 52 at both ends of connecting arm 4, can accurately obtain the settlement of bearing plate 1, realize the in-situ testing of the deformation modulus of subgrade soil under actual construction scenarios, without the need for soil sampling, avoid soil disturbance, improve the testing accuracy, solve the shortcomings of current indoor tests, and can make a real and accurate assessment of the bearing capacity and stability of the subgrade under test.

[0045] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0046] The above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. An in-situ testing device for the deformation modulus of roadbed soil, characterized in that, include: A bearing plate, the bottom surface of which is pressed against the roadbed to be tested, and a force transmission column protruding from its top surface, with strain gauges attached to the side wall of the force transmission column; The jack has its force-applying end in contact with the top of the force-transmitting column, so as to load and unload the load onto the bearing plate through the force-transmitting column. A support frame is installed on an undisturbed flat surface outside the roadbed to be tested; A connecting arm extends horizontally above the support frame, and the middle part of the connecting arm is rotatably connected to the support frame; one end of the connecting arm is provided with a probe, which presses against the top surface of the bearing plate, and the other end of the connecting arm is provided with a dial indicator; When the jack loads and unloads the bearing plate via the force transmission column, the settlement of the bearing plate is obtained using the dial gauge, and the normal average stress of the bearing plate is obtained using the strain gauge.

2. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1, characterized in that, The force transmission column is vertically connected to the center of the top surface of the bearing plate. The force transmission column includes a core and a cylinder that are connected to each other and coaxially arranged. The cylinder is connected between the bearing plate and the core. The strain gauge is attached to the side wall of the core. The side wall of the cylinder has a detection window that communicates with the inner cavity of the cylinder. The probe at one end of the connecting arm extends into the inner cavity of the cylinder through the detection window and presses against the center of the top surface of the bearing plate.

3. The in-situ testing device for the deformation modulus of subgrade soil according to claim 2, characterized in that, The in-situ detection device for the deformation modulus of the subgrade soil also includes a limiting frame, which is set on the side of the support frame away from the subgrade to be tested; the limiting frame includes two columns arranged opposite each other and two limiting rods connected between the two columns and arranged opposite each other vertically; the end of the connecting arm away from the subgrade to be tested extends into the space between the two limiting rods.

4. The in-situ testing device for the deformation modulus of subgrade soil according to claim 3, characterized in that, The limiting frame also includes a limiting post disposed between two columns, the limiting post being connected to two limiting rods; the connecting arm includes a first straight arm, a second straight arm, and a bent arm connected in sequence, the end of the first straight arm near the second straight arm being rotatably connected to the support frame, the first straight arm including two parallel supporting arms and a connecting arm connecting the same end of the two supporting arms, the two supporting arms respectively extending between the limiting post and the two columns, the connecting arm being located on the side of the limiting post away from the support frame, and the dial indicator being connected between the two supporting arms; the bent arm includes a vertical arm and a horizontal arm, the upper end of the vertical arm being connected to the end of the second straight arm away from the first straight arm, one end of the horizontal arm being connected to the lower end of the vertical arm, and the other end of the horizontal arm passing through the detection window and extending into the inner cavity of the column, and the probe being provided at this end.

5. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1, characterized in that, The support frame includes two support columns arranged opposite each other and a support rod connected between the two support columns. Two supports are provided on the support rod at intervals along its length. The connecting arm is clamped between the two supports. A rotating hole is opened on the support. A rotating shaft passes through the connecting arm. The rotating shaft is inserted into the rotating hole of the two supports so that the connecting arm is rotatably connected to the support frame.

6. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1 or 5, characterized in that, The ratio of the horizontal distance between the rotation point of the connecting arm on the support frame and the probe to its horizontal distance to the dial indicator is not greater than 2.

7. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1, characterized in that, The in-situ testing device for the deformation modulus of the subgrade soil also includes a chassis, which is detachably connected to the bottom surface of the bearing plate and pressed against the subgrade to be tested; the chassis and the bearing plate are coaxially arranged, and the diameter of the chassis is larger than the diameter of the bearing plate.

8. The in-situ testing device for the deformation modulus of subgrade soil according to claim 7, characterized in that, A pin is provided between the chassis and the bearing plate; the chassis is detachably connected to the bearing plate through multiple connecting parts, the connecting parts including a fixing plate, a clamping plate, and a connecting plate connecting the fixing plate and the clamping plate, the fixing plate is detachably connected to the top surface of the chassis by bolts, and the bottom surface of the clamping plate is pressed against the top surface of the bearing plate.

9. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1, characterized in that, A level is provided on the top surface of the support plate.

10. The in-situ testing device for the deformation modulus of subgrade soil according to claim 1, characterized in that, Multiple handles are provided on the top surface of the bearing plate and the top surface of the connecting arm.

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