A method and device for on-site testing of soil Poisson's ratio

Abstract

The present application provides a method and device for on-site testing of the Poisson's ratio of soil, the device comprising an aluminum angle, and an inclinometer mounted on the aluminum angle; a Poisson's ratio calibration unit for calibrating the relationship between different Poisson's ratios and the angle of inclination of the aluminum angle when different vertical loads are applied, and a collection unit for collecting data on the angle of inclination of the aluminum angle when different vertical loads are applied to the soil to be tested. The method steps are: constructing a curve showing the change of horizontal stress with soil depth in soils with different Poisson's ratios; applying different pressure combinations under different Poisson's ratios, measuring the angle of inclination of the aluminum angle measured by the inclinometer under different pressure combinations, and constructing a curve showing the relationship between Poisson's ratio and inclination angle, applying a vertical load to the center of the pressure plate placed on the soil to be tested, recording the angle of inclination of the aluminum angle, and calculating the Poisson's ratio of the soil to be tested based on the curve showing the relationship between Poisson's ratio and inclination angle. The present application does not require sampling of the soil to be tested, does not cause disturbance to the soil to be tested, and provides more accurate test results.

Description

Technical Field

[0001] The present invention relates to the technical field of Poisson's ratio measurement, in particular to a method and a device for on-site testing of the Poisson's ratio of soil. Background Art

[0002] Poisson's ratio is an important mechanical parameter of soil. The deformation, lateral stress, strength and stability of soil are all related to Poisson's ratio. Since soil is a granular body, its Poisson's ratio test is very difficult. The existing soil Poisson's ratio test methods are mainly aimed at clay, and all belong to indoor test tests. For example, in the invention patent with application number CN201410254901.3 "A device and method for measuring the Poisson's ratio of soil", it is disclosed that a flexible steel ring is set on the outer ring of the soil column to be tested, and a resistance strain gauge is bonded to the outer side of the steel ring to test the lateral strain of the soil column after being compressed. The Poisson's ratio of soil is obtained according to the ratio of lateral strain and vertical strain; in the invention patent with application number CN201921609781.9 "A device for measuring the actual Poisson's ratio of foundation soil under lateral limit stress conditions" It is disclosed that several miniature soil pressure gauges are evenly distributed along the circumference on the inner surface of the side limit box of the soil sample, the lateral stress is tested by the soil pressure gauge, and the lateral stress and vertical stress are substituted into the relevant formula to obtain the Poisson's ratio of the soil; in the invention patent with application number CN201810120191.3 "Soil Poisson's Ratio Measurement Method, Device and System", it is disclosed that CT plane scanning is used to obtain the change values ​​of the axial length and radial length of the soil before and after compression, convert them into strain, and calculate the Poisson's ratio of the soil.

[0003] Indoor testing requires on-site sampling, which itself will disturb the soil and affect the accuracy of the test results. On the other hand, many soils in engineering projects, such as sand and gravel, cannot be sampled regularly, so their Poisson's ratio cannot be tested through indoor testing.

[0004] Based on the shortcomings of existing technologies, a field testing method and device for Poisson's ratio are designed, which has important engineering significance. Summary of the Invention

[0005] An object of the present invention is to provide a device for testing the Poisson's ratio of soil on site.

[0006] The object of the present invention is achieved by such a technical solution, comprising an angle aluminum, and an inclinometer mounted on the angle aluminum;

[0007] A Poisson's ratio calibration unit is provided for calibrating the relationship between different Poisson's ratios and the angle aluminum tilt angle when different vertical loads are applied, and a collection unit is provided for collecting angle aluminum tilt angle data of the soil to be tested when different vertical loads are applied.

[0008] Furthermore, the Poisson's ratio calibration unit includes a model box with an upper opening, a filling material, a thrust component, and a sliding limit component;

[0009] One side wall of the model box is provided with an opening, and a sliding limit assembly that can slide inward is provided on the side wall of the model box with the opening, and a thrust assembly is provided on the outside of the model box to push the sliding limit assembly to slide inward of the model box, and the filling material is used to press the lower end of the vertically placed angle aluminum and fill the model box during calibration;

[0010] The inclinometer is used to collect angle data of aluminum corners, and the inclination angle data is used to construct a relationship curve between Poisson's ratio and inclination angle.

[0011] Furthermore, the sliding limit assembly includes a plurality of sliding plates arranged in sequence along the vertical direction, and the plurality of sliding plates can slide independently;

[0012] The thrust assembly includes a plurality of power output modules respectively used for pushing a plurality of sliding plates, and the number of the power output modules is the same as the number of the sliding plates.

[0013] Furthermore, the collection unit includes a flexible pressure plate. When collecting data, the flexible pressure plate is placed on the surface of the soil to be tested. Test pits are excavated in the soil on both sides of the flexible pressure plate. Angle aluminum is placed vertically in the test pits and filled and compacted with filling materials.

[0014] Furthermore, the filling material is fine dry sand.

[0015] An object of the present invention is to provide a method for testing the Poisson's ratio of soil on site.

[0016] The object of the present invention is achieved through such a technical solution, using the above-mentioned device for on-site testing of the Poisson's ratio of soil, the specific steps are:

[0017] 1) Construct depth stress curve: Calculate the horizontal stress at different depths at a distance x from the load application point when a load of P is applied to the surface of the soil with different Poisson's ratios. Constructing the horizontal stress magnitude in soils with different Poisson's ratios Curve changing with soil depth z

[0018] 2) Construct Poisson's ratio inclination angle curve: insert the angle aluminum into the fine dry sand in the model box, and apply pressure combinations F under different Poisson's ratios to several sliding plates. i , measure the aluminum inclination angle θ measured by the inclinometer under different pressure combinations, and construct the relationship curve μ-θ between Poisson's ratio μ and the inclination angle θ;

[0019] 3) Poisson's ratio measurement: Place the flexible bearing plate on the surface of the soil to be tested, dig test pits on both sides of the flexible bearing plate, insert the angle aluminum into the fine dry sand in the test pit, apply a vertical load to the center of the bearing plate, and record the inclination angle θ of the angle aluminum s Calculate the Poisson's ratio μ of the soil to be tested according to the μ-θ curve in step 2). s .

[0020] Furthermore, the specific steps for constructing the depth stress curve in step 1) are:

[0021] 1-1) Calculate the horizontal stress at different depths z when a vertical load of P is applied to the surface of soil with different Poisson's ratios and the horizontal distance between the stress measurement point and the vertical load application point is x. distributed:

[0022]

[0023] Where R is the spatial distance between the measurement point and the load application point;

[0024] 1-2) Construct the curve of horizontal stress distribution with soil depth in soils with different Poisson's ratios

[0025] Furthermore, the specific steps of constructing the Poisson's ratio tilt angle relationship curve in step 2) are:

[0026] 2-1) Place the aluminum angle into the model box, and add fine dry sand from a height of H above the bottom of the model box. c Pour into the model box, fill the model box and make the bottom of the angle aluminum buried to a depth of H m ;

[0027] 2-2) Apply pressure F to several sliding plates through the power output module i , where: i∈(1~n), n is the maximum number of sliding plates:

[0028]

[0029] Where S i is the cross-sectional area of ​​the sliding plate, the distance between the midpoint of the sliding plate in the width direction and the upper surface of the fine dry sand in the model box is z, is the horizontal stress at depth z when Poisson's ratio is μ;

[0030] 2-3) Repeat steps 2-1) to 2-2) to record the aluminum inclination angle θ measured by the inclinometer at different Poisson's ratios, and construct a relationship curve μ-θ between the Poisson's ratio and the inclination angle.

[0031] Furthermore, the specific steps of measuring the Poisson's ratio in step 3) are:

[0032] 3-1) Place the flexible pressure plate on the surface of the soil to be tested, and dig test pits on both sides of the flexible pressure plate at a distance x from the center point;

[0033] 3-2) Add fine dry sand from the same height H as the model calibration in step 2) c Pour the sand into the test pit. When pouring the fine dry sand, place the angle aluminum with the inclinometer in the test pit. The insertion depth of the angle aluminum in the fine dry sand should be the same as the depth H of the model calibration in step 2). m same;

[0034] 3-3) Apply a vertical load P to the center of the flexible bearing plate and use the inclinometer to record the inclination angle θ of the angle aluminum. s ;

[0035] 3-4) Change the tilt angle θ in step 3-3) to s Import the μ-θ curve in step 2) and calculate the Poisson's ratio μ of the soil to be tested s .

[0036] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0037] 1. The on-site test of this application does not require sampling of the soil to be tested, does not disturb the soil to be tested, and the test results are more accurate.

[0038] 2. This application can solve the problem of Poisson's ratio testing of soils that are difficult to sample, such as sand and gravel, and has a wide range of applications.

[0039] 3. This application measures the inclination angle of the angle aluminum and constructs a curve of the inclination angle and Poisson's ratio. The inclination angle is not affected by the deformation modulus of the soil and can effectively eliminate the influence of the deformation modulus of the soil.

[0040] Other advantages, objectives, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings of the present invention are described below.

[0042] Figure 1 The figure is a flow chart of the method for on-site testing of the Poisson's ratio of soil according to the present invention.

[0043] Figure 2 1 is a top view of the Poisson's ratio calibration unit of the present invention.

[0044] Figure 3 It is a cross-sectional view of the Poisson's ratio calibration unit of the present invention.

[0045] Figure 4 This is a top view of the collection unit of the present invention.

[0046] Figure 5 It is a cross-sectional view of the collection unit of the present invention.

[0047] Figure 6 This is the curve showing the change of horizontal stress distribution in soils with different Poisson's ratios as a function of soil depth in the present invention.

[0048] Figure 7 This is the relationship curve between Poisson's ratio and the inclination angle of the angle aluminum in the present invention.

[0049] In the figure: 1-angle aluminum; 2-inclinometer; 3-model box; 4-filling material; 5-sliding plate; 6-flexible pressure plate; 7-test pit; 8-slide rail. DETAILED DESCRIPTION

[0050] The present invention will be further described below with reference to the accompanying drawings and examples.

[0051] Example 1:

[0052] like Figure 2-5 The device shown is for testing the Poisson's ratio of soil on site, comprising an aluminum angle 1 and an inclinometer 2 mounted on the aluminum angle 1;

[0053] A Poisson's ratio calibration unit is provided for calibrating the relationship between different Poisson's ratios and the tilt angle of the angle aluminum 1 when different vertical loads are applied, and a collection unit is provided for collecting the tilt angle data of the tested soil when different vertical loads are applied.

[0054] In the example of the present invention, the inclinometer 2 is used to measure the inclination angle of the angle aluminum 1. When calibrating the Poisson's ratio, the angle aluminum 1 is vertically inserted into the model box 3. When collecting the inclination angle data of the angle aluminum 1 when different vertical loads are applied to the soil to be tested, the angle aluminum 1 is vertically inserted into the test pit 7 of the soil to be tested; the horizontal displacement of the angle aluminum 1 is affected by the deformation modulus of the soil, while the inclination angle is not affected by the deformation modulus of the soil. Selecting the inclination angle as the basis for determining the Poisson's ratio can eliminate the influence of the soil deformation modulus.

[0055] As an embodiment of the present invention, the Poisson's ratio calibration unit includes a model box 3 with an upper end opening, a filling material 4, a thrust component, and a sliding limit component;

[0056] One side wall of the model box 3 is provided with an opening, and a sliding limit assembly that can slide inward is provided on the side wall of the opening of the model box 3. The sliding limit assembly is located on the outside of the model box 3 and is provided with a thrust assembly. The thrust assembly is used to push the sliding limit assembly to slide inward of the model box 3. The filling material 4 is used to press the lower end of the vertically placed angle aluminum 1 and fill the model box 3 during calibration;

[0057] The inclinometer 2 is used to collect inclination angle data of the angle aluminum 1, and the inclination angle data is used to construct a relationship curve between Poisson's ratio and inclination angle.

[0058] In this example of the present invention, the filling material 4 is fine dry sand, and the specific steps of Poisson's ratio calibration are as described in the method for on-site testing of the Poisson's ratio of soil in Example 2.

[0059] As an embodiment of the present invention, the sliding limit assembly includes a plurality of sliding plates 5 arranged in sequence along the vertical direction, and the plurality of sliding plates 5 can slide independently;

[0060] The thrust assembly includes a plurality of power output modules respectively used to push a plurality of sliding plates 5 , and the number of the power output modules is the same as the number of the sliding plates 5 .

[0061] In the example of the present invention, slide rails 8 are installed on the side walls of the model box 3 on both sides of the sliding plate 5, and slide grooves (not shown in the figure) are provided at both ends of the sliding plate 5. The sliding plate 5 can slide along the slide rails 8 toward the inside of the model box 3, and each sliding plate 5 is ejected by a separate power output module (not shown in the figure).

[0062] As an embodiment of the present invention, the collection unit includes a flexible pressure plate 6. When collecting data, the flexible pressure plate 6 is placed on the surface of the soil to be tested. Test pits 7 are excavated in the soil on both sides of the flexible pressure plate 6. Angle aluminum 1 is placed vertically in the test pit 7 and filled and compacted with filling material 4.

[0063] In this embodiment of the present invention, fine dry sand is used as the filling material 4. The specific steps for collecting the inclination angle data of the angle aluminum 1 when different vertical loads are applied to the soil to be tested are as described in the method for testing the Poisson's ratio of soil in the field in Example 2.

[0064] Example 2:

[0065] like Figure 1 A method for testing the Poisson's ratio of soil on site is shown, using the above-mentioned device for testing the Poisson's ratio of soil on site, and the specific steps are as follows:

[0066] 1) Construct depth stress curve: Calculate the horizontal stress at different depths at a distance x from the load application point when a load of P is applied to the surface of the soil with different Poisson's ratios. Constructing the horizontal stress magnitude in soils with different Poisson's ratios Curve changing with soil depth z The specific steps are:

[0067] 1-1) Calculate the horizontal stress at different depths z when a vertical load of P is applied to the surface of soil with different Poisson's ratios and the horizontal distance between the stress measurement point and the vertical load application point is x. distributed:

[0068]

[0069] Where R is the spatial distance between the measurement point and the load application point;

[0070] 1-2) Construct the curve of horizontal stress distribution with soil depth in soils with different Poisson's ratios

[0071] In the present invention, based on prior art, it is known that under a vertical load on the soil surface, the horizontal stress distribution along the depth direction at the same distance from the load point is related to the soil's Poisson's ratio. Within a certain depth range, the smaller the soil's Poisson's ratio, the greater the horizontal stress, and the more uniform the vertical distribution along the depth direction. Conversely, the larger the soil's Poisson's ratio, the smaller the horizontal stress, and the more uneven the vertical distribution along the depth direction, with smaller stress at the top and larger stress at the bottom.

[0072] In the embodiment of the present invention, the load P applied to the soil surface is 9 kN, and x is 0.6 m. The horizontal stress distribution curves of soils with different Poisson's ratios as a function of soil depth are constructed. like Figure 6 As shown, Figure 6 The horizontal stress is minimum when the Poisson's ratio μ=0.27, and the horizontal stress is approximately equal between 0-0.15m. The horizontal stress is maximum when μ=0.39, and the horizontal stress gradually increases with increasing depth between 0-0.15m.

[0073] 2) Construct Poisson's ratio inclination angle curve: insert the aluminum angle 1 into the fine dry sand in the model box 3, and apply pressure combinations F under different Poisson's ratios to several sliding plates 5. i , measure the inclination angle θ of the angle aluminum 1 measured by the inclinometer 2 under different pressure combinations, and construct the relationship curve μ-θ between the Poisson's ratio μ and the inclination angle θ; the specific steps are:

[0074] 2-1) Place the aluminum angle 1 into the model box 3, and add fine dry sand from a height of H from the bottom of the model box 3. c Pour into the model box 3, fill the model box 3 and make the bottom of the angle aluminum 1 buried to a depth of H m .

[0075] In this example of the present invention, the model box 3 is 350 mm wide, 380 mm long and 200 mm deep; the angle side of the angle aluminum 1 is 100 mm long, 5 mm thick and 230 mm long; the lower end of the angle aluminum 1 is inserted into the fine dry sand to a depth of 150 mm.

[0076] 2-2) Apply pressure F to the sliding plates 5 through the power output module i , where: i∈(1~n), n is the maximum number of sliding plates 5:

[0077]

[0078] Where S i is the cross-sectional area of ​​the sliding plate 5, the distance between the midpoint of the width direction of the sliding plate 5 and the upper surface of the fine dry sand in the mold box 3 is z, is the horizontal stress at depth z when Poisson's ratio is μ.

[0079] In the present embodiment, the number of the sliding plates 5 is 4, the horizontal width of a single sliding plate 5 is 350 mm, the vertical width of a single sliding plate 5 is 50 mm, and the cross-sectional area S of the sliding plate 5 is i is the product of the horizontal width and the vertical width. Based on the above parameters, the pressure combinations under different Poisson's ratios are calculated as shown in Table 1.

[0080] Table 1 Pressure combinations under different Poisson's ratios

[0081]

[0082] 2-3) Repeat steps 2-1) to 2-2) to record the angle of inclination θ measured by the inclinometer 2 under different Poisson's ratios, and construct a relationship curve μ-θ between the Poisson's ratio and the inclination angle. Figure 7 shown.

[0083] 3) Poisson's ratio measurement: Place the flexible bearing plate 6 on the surface of the soil to be tested, dig test pits 7 on both sides of the flexible bearing plate, insert the angle aluminum 1 into the fine dry sand in the test pit 7, apply a vertical load to the center of the bearing plate, and record the inclination angle θ of the angle aluminum 1 s Calculate the Poisson's ratio μ of the soil to be tested according to the μ-θ curve in step 2). s , the specific steps are:

[0084] 3-1) Place the flexible pressure plate 6 on the surface of the soil to be tested, and dig test pits 7 on both sides of the flexible pressure plate 6 at a distance x from the center point thereof;

[0085] 3-2) Add fine dry sand from the same height H as the model calibration in step 2) cPour the sand into the test pit 7. When pouring the fine dry sand, place the angle aluminum 1 equipped with the inclinometer 3 in the test pit 7. The insertion depth of the angle aluminum 1 in the fine dry sand is the same as the depth H of the model calibration in step 2). m same;

[0086] 3-3) Apply a vertical load P to the center of the flexible bearing plate 6 and record the inclination angle θ of the angle aluminum 1 through the inclinometer 2 s ;

[0087] 3-4) Change the tilt angle θ in step 3-3) to s Import the μ-θ curve in step 2) and calculate the Poisson's ratio μ of the soil to be tested s .

[0088] In this example, the flexible pressure plate 6 measures 300 x 300 mm. Test pits 7 are dug on either side of the plate 6, 0.6 m from its center. Test pits 7 are 250 mm wide, 210 mm long, and 200 mm deep. The lower portion of the angle aluminum 1 is inserted into the fine dry sand in the test pits 7 to a depth of 150 mm. A vertical load P = 9 kN is applied to the center of the flexible pressure plate 6. This vertical load P is applied using conventional external load application methods, which are not limited in this application.

[0089] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0090] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for testing the Poisson's ratio of soil on site, characterized in that: A device for testing the Poisson's ratio of soil on site is used, the device comprising an aluminum angle (1), and an inclinometer (2) mounted on the aluminum angle (1); a Poisson's ratio calibration unit for calibrating the relationship between different Poisson's ratios and the inclination angle of the aluminum angle (1) when different vertical loads are applied, and a collection unit for collecting data on the inclination angle of the aluminum angle (1) when different vertical loads are applied to the soil to be tested; The Poisson's ratio calibration unit comprises a model box (3) with an opening at the top, a filling material (4), a thrust assembly, and a sliding limit assembly; one side wall of the model box (3) is provided with an opening, and a sliding limit assembly that can slide inward is provided on the side wall of the model box (3) with the opening; the sliding limit assembly is provided with a thrust assembly on the outside of the model box (3); the thrust assembly is used to push the sliding limit assembly to slide inward of the model box (3); the filling material (4) is used to press the lower end of the vertically placed angle aluminum (1) and fill the model box (3) during calibration; the inclinometer (2) is used to collect inclination angle data of the angle aluminum (1), and the inclination angle data is used to construct a relationship curve between the Poisson's ratio and the inclination angle; The sliding limit assembly comprises a plurality of sliding plates (5) arranged in sequence along a vertical direction, and the plurality of sliding plates (5) can slide independently; the thrust assembly comprises a plurality of power output modules respectively used to push the plurality of sliding plates (5), and the number of the power output modules is the same as the number of the sliding plates (5); The acquisition unit comprises a flexible pressure-bearing plate (6). When collecting data, the flexible pressure-bearing plate (6) is placed on the surface of the soil to be tested. Test pits (7) are excavated in the soil on both sides of the flexible pressure-bearing plate (6). Angle aluminum (1) is vertically placed in the test pit (7) and is filled and compacted with filling material (4). The method for testing the Poisson's ratio of soil on site includes the following steps: 1) Construct depth stress curve: Calculate the horizontal stress at different depths at a distance x from the load application point when a load of P is applied to the surface of the soil with different Poisson's ratios. Constructing the horizontal stress magnitude in soils with different Poisson's ratios Curve changing with soil depth z 2) Constructing the Poisson's ratio inclination angle curve: insert the angle aluminum (1) into the fine dry sand in the model box (3), and apply pressure combinations F under different Poisson's ratios to several sliding plates (5) respectively. i , measuring the inclination angle θ of the angle aluminum (1) measured by the inclinometer (2) under different pressure combinations, and constructing a relationship curve μ-θ between the Poisson's ratio μ and the inclination angle θ; 3) Poisson's ratio measurement: Place the flexible pressure plate (6) on the surface of the soil to be tested, dig test pits (7) on both sides of the flexible pressure plate, insert the angle aluminum (1) into the fine dry sand in the test pit (7), apply a vertical load to the center of the pressure plate, and record the inclination angle θ of the angle aluminum (1) s Calculate the Poisson's ratio μ of the soil to be tested according to the μ-θ curve in step 2). s .

2. The method for testing the Poisson's ratio of soil on site according to claim 1, wherein: The specific steps for constructing the depth stress curve in step 1) are: 1-1) Calculate the horizontal stress at different depths z when a vertical load of P is applied to the surface of soil with different Poisson's ratios and the horizontal distance between the stress measurement point and the vertical load application point is x. distributed: Where R is the spatial distance between the measurement point and the load application point; 1-2) Construct the curve of horizontal stress distribution with soil depth in soils with different Poisson's ratios 3. The method for testing the Poisson's ratio of soil on site according to claim 1, wherein: The specific steps for constructing the Poisson's ratio tilt angle relationship curve in step 2) are: 2-1) Place the aluminum angle (1) into the model box (3), and add fine dry sand from the bottom of the model box (3) to a height of H. c Pour into the model box (3), fill the model box (3) and make the bottom of the angle aluminum (1) buried to a depth of H m ; 2-2) Apply pressure F to the plurality of sliding plates (5) through the power output module i , where: i∈(1~n), n is the maximum number of sliding plates (5): Where S i is the cross-sectional area of ​​the sliding plate (5), the distance between the midpoint of the width direction of the sliding plate (5) and the upper surface of the fine dry sand in the model box (3) is z, is the horizontal stress at depth z when Poisson's ratio is μ; 2-3) Repeat steps 2-1) to 2-2) to record the angle of inclination θ of the aluminum angle measured by the inclinometer (2) under different Poisson's ratios, and construct a relationship curve μ-θ between the Poisson's ratio and the inclination angle.

4. The method for testing the Poisson's ratio of soil on site according to claim 1, wherein: The specific steps of measuring Poisson's ratio in step 3) are: 3-1) placing the flexible pressure-bearing plate (6) on the surface of the soil to be tested, and digging test pits (7) at positions x from the center point of the flexible pressure-bearing plate (6) on both sides; 3-2) Add fine dry sand from the same height H as the model calibration in step 2) c Pour the fine sand into the test pit (7), and place the angle aluminum (1) equipped with the inclinometer (2) in the test pit (7) when pouring the fine dry sand. The insertion depth of the angle aluminum (1) in the fine dry sand is the same as the depth H calibrated by the model in step 2). m same; 3-3) Apply a vertical load P to the center of the flexible bearing plate (6) and record the inclination angle θ of the angle aluminum (1) using the inclinometer (2) s ; 3-4) Change the tilt angle θ in step 3-3) to s Import the μ-θ curve in step 2) and calculate the Poisson's ratio μ of the soil to be tested s .

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