A multifunctional soil taking device

Abstract

The present invention provides a multifunctional soil sampling device, including a soil sampling system, a resistivity testing system, a soil strength testing system, a shell and a controller; the soil sampling system includes a soil sampling tube; the soil sampling tube is arranged in the shell; the resistivity testing system is provided with a plurality of annular electrodes, and the plurality of annular electrodes are installed on the inner wall of the shell from top to bottom through an insulating plastic layer; the resistivity testing system is connected to the controller; the soil strength testing system includes a stepper motor, a torque sensor and a shearing mechanism; the stepper motor is connected to the upper part of the shell, the shearing mechanism is installed on the shell, and the torque sensor is respectively connected to the stepper motor and the controller. The present invention can not only quickly measure the resistivity and the shear strength of the soil on the in-situ soil, but also perform soil sampling work, integrating multiple functions into one, greatly improving the efficiency of geological survey, and saving test costs.

Description

Technical Field

[0001] The invention belongs to the technical field of geotechnical engineering, and in particular relates to a multifunctional soil taking device. Background Art

[0002] In the process of geotechnical engineering testing, it is often necessary to collect soil samples, and then take samples of soil from different strata for geotechnical tests to understand their physical and mechanical properties. However, the geological conditions of each engineering area are different, and different testing projects have different requirements for soil sampling depth and soil sample size. The quality of soil samples is divided into levels I, II, III, and IV according to the purpose of the test. Level I soil samples: undisturbed, soil classification, water content, density, strength and consolidation tests can be carried out; Level II soil samples: slightly disturbed, soil classification, water content, and density tests can be carried out; Level III soil samples: significantly disturbed, soil classification and water content tests can be carried out; Level IV soil samples: completely disturbed, soil classification can be carried out as much as possible.

[0003] Soil resistivity is a basic parameter that characterizes the conductivity of soil. It is an inherent physical index of soil and depends on the porosity, pore shape, pore water resistivity, saturation, water content, solid particle composition, etc. In the field of geotechnical engineering investigation and environmental geotechnical engineering, the resistivity parameter of soil layer is an important physical index. In the field of geotechnical engineering investigation, in-situ cross-plate shear test is usually used to determine the undrained shear strength of saturated soft clay, the undrained shear strength of remolded soil and the sensitivity of soil.

[0004] Earth samplers are widely used in geotechnical engineering investigation and environmental geotechnical engineering fields, but their functions are relatively simple, which greatly limits their scope of application. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a soil sampling device capable of measuring resistivity. The present invention can not only quickly measure the resistivity and the shear strength of the soil on the in-situ soil, but also perform soil sampling. It integrates multiple functions in one and has the functions of synchronously testing the resistivity and shear strength of the soil and sampling the soil, which greatly improves the efficiency of geological survey and saves the test cost.

[0006] The present invention is realized by the following technical scheme: a multifunctional original soil sampling device, comprising a soil sampling system, a resistivity testing system, a soil strength testing system, a housing and a controller;

[0007] The soil taking system comprises a soil taking pipe; the soil taking pipe is arranged in the housing;

[0008] The resistivity testing system is provided with a plurality of annular electrodes, which are installed on the inner wall of the housing from top to bottom through an insulating plastic layer; the resistivity testing system is connected to a controller;

[0009] The soil strength testing system comprises a stepper motor, a torque sensor and a shearing mechanism; the stepper motor is connected to the upper part of the shell, the shearing mechanism is installed on the shell, and the torque sensor is connected to the stepper motor and the controller respectively.

[0010] In the above scheme, the resistivity testing system includes a first annular electrode, a second annular electrode, a third annular electrode and a fourth annular electrode; the first annular electrode, the second annular electrode, the third annular electrode and the fourth annular electrode are sequentially installed on the inner wall of the shell from top to bottom through an insulating plastic layer.

[0011] Furthermore, the shell is provided with a hollow interlayer; a circuit and a signal processing system are arranged in the hollow interlayer; and the signal processing system is connected to the controller through the circuit and the resistivity test system.

[0012] Further, the signal processing system includes an A / D signal converter, a current filter, a voltage filter and a voltage amplifier;

[0013] The first annular electrode, the fourth annular electrode, the current amplifier and the current filter are connected in series, the second annular electrode, the third annular electrode, the voltage amplifier and the voltage filter are connected in series, the two series circuits are connected in parallel and the current signal is converted into a digital signal through an A / D signal converter and sent to the controller.

[0014] In the above solution, the distances between adjacent annular electrodes are equal.

[0015] In the above solution, the shearing mechanism includes four shearing plates; the four shearing plates are arranged on the shell in pairs opposite to each other.

[0016] In the above solution, the stepper motor is connected to the upper part of the housing via an extension rod.

[0017] Furthermore, it also includes a hydraulic device; the hydraulic device is installed on the extension rod.

[0018] In the above scheme, a drainage channel is provided on the upper part of the shell; a ball valve is provided in the drainage channel, and one end of the drainage channel is connected to the soil taking pipe, and the other end is connected to the outside.

[0019] In the above solution, the soil taking pipe can be opened to the left and right.

[0020] Compared with the prior art, the invention has the following beneficial effects: the invention can continuously test the soil resistivity and the shear strength of the soil in the in-situ test, and can also realize soil sampling at the same time, integrating multiple functions into one, greatly improving the efficiency of geological survey, and saving the test cost. The invention also makes improvements on the traditional soil sampling device, greatly reduces the disturbance of the soil during the soil sampling process, performs in-situ measurement of the resistivity of the soil layer on site, and effectively improves the accuracy of resistivity measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic cross-sectional view of a multifunctional soil taking device according to one embodiment of the present invention.

[0022] Figure 2 It is a schematic structural diagram of an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of the structure of a soil sampling pipe according to one embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of opening the soil sampling pipe according to one embodiment of the present invention.

[0025] In the figure: 1. controller; 2. stepper motor; 3. torque sensor; 4. hydraulic device; 5. circuit; 6. extension rod; 7. A / D signal converter; 8. drainage hole; 9. ball valve; 10. current filter; 11. first annular electrode; 12. voltage filter; 13. soil sampling pipe; 14. second annular electrode; 15. hollow interlayer; 16. insulating paint; 17. current amplifier; 18. third annular electrode; 19. fourth annular electrode; 20. insulating plastic layer; 21. shear plate; 22. outer wall of hollow interlayer; 23. inner wall of hollow interlayer; 25. inside of soil sampling pipe; 26. soil sampling pipe; 27. bolt Ⅰ; 28. bolt Ⅱ. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Figure 1 The figure shows a preferred embodiment of the multifunctional undisturbed soil sampler, which includes a soil sampling system, a resistivity testing system, a soil strength testing system, a housing and a controller 1.

[0030] like Figure 2 As shown, the soil sampling system includes a soil sampling tube 26; the soil sampling tube 26 is arranged in the shell; the resistivity testing system is provided with a plurality of annular electrodes, and the plurality of annular electrodes are installed on the inner wall of the shell in sequence and equidistantly from top to bottom through the insulating plastic layer 20; the resistivity testing system is connected to the controller 1; the soil strength testing system includes a stepper motor 2, a torque sensor 3 and a shear mechanism; the stepper motor 2 is connected to the upper part of the shell, the shear mechanism is installed on the shell, and the torque sensor 3 is respectively connected to the stepper motor 2 and the controller 1.

[0031] The resistivity testing system includes four copper annular electrodes: a first annular electrode 11, a second annular electrode 14, a third annular electrode 18 and a fourth annular electrode 19; the first annular electrode 11, the second annular electrode 14, the third annular electrode 18 and the fourth annular electrode 19 are sequentially installed on the inner wall of the shell from top to bottom through an insulating plastic layer 20.

[0032] The shell is provided with a hollow interlayer 15, and includes a hollow interlayer outer wall 22 and a hollow interlayer inner wall 23; a circuit 5 and a signal processing system are arranged in the hollow interlayer 15; the signal processing system is connected to the resistivity test system and the controller 1 through the circuit 5.

[0033] The signal processing system includes an A / D signal converter 7, a current filter 10, a voltage filter 12 and a voltage amplifier 13; the first annular electrode 11, the fourth annular electrode 19, the current amplifier 17 and the current filter 10 are connected in series, the second annular electrode 14, the third annular electrode 18, the voltage amplifier 13 and the voltage filter 12 are connected in series, the two series circuits are connected in parallel and the current signal is converted into a digital signal through the A / D signal converter 7 and sent to the controller 1.

[0034] The distances between adjacent annular electrodes on the soil sampling pipe 26 are all equal.

[0035] The shearing mechanism comprises four shearing plates 21; the four shearing plates 21 are arranged on the housing in pairs opposite to each other.

[0036] The stepper motor 2 is threadedly connected to the upper part of the housing via an extension rod 6 .

[0037] It also includes a hydraulic device 4 ; the hydraulic device 4 is installed on the extension rod 6 .

[0038] A drainage channel 8 is provided on the upper part of the housing; a ball valve 9 is provided in the drainage channel 8, and one end of the drainage channel 8 is connected to the soil pipe 26, and the other end is connected to the outside. The drainage channel 8 is used to discharge groundwater in the deep soil. The ball valve 9 originally blocks the drainage channel 8. When the groundwater enters the soil pipe 26, the water pressure pushes up the ball of the ball valve 9, and the drainage channel 8 is opened. After the water flows out of the soil extractor through the drainage channel 8, the ball of the ball valve 9 returns to its original position to block the outlet of the drainage channel 8.

[0039] like Figure 3 and 4 As shown, the soil sampling tube 26 can be split into two parts, and the interior 25 of the soil sampling tube is used for soil sampling. Specifically, the lower part of the soil sampling tube 26 is provided with symmetrical bolts I27 and bolts II28, and the soil sampling tube 26 can be split and disassembled after being sent to the laboratory. This method is also conducive to less disturbance of the soil sample and better obtaining the parameters of the soil body.

[0040] Working process of the present invention:

[0041] First, the soil to be tested is drilled with a deep hole drill. After drilling to the measuring depth, the hydraulic device 4 is used to drive the device into the soil to the bottom of the hole. After inserting to the predetermined depth, the constant current power supply is turned on, and a sinusoidal wave test current with a frequency of 65Hz and an effective value of 0-5A is input to the first annular electrode 11 and the fourth annular electrode 19. The current flows through the surrounding soil into the second annular electrode 14 and the third annular electrode 18, and a voltage is formed between the second annular electrode 14 and the third annular electrode 18.

[0042] The distance between adjacent annular electrodes on the soil sampling tube 26 is a, and an insulating plastic layer 20 is installed between the annular electrodes and on the outside. The voltage amplifier 13 amplifies the voltage between the second annular electrode 14 and the third annular electrode 18 and sends it to the voltage filter 12. The current amplifier 17 amplifies the current signal measured by the second annular electrode 14 and the third annular electrode 18 and sends it to the current filter 10. The voltage filter 12 and the current filter 10 are used to filter out interference signals and only allow valid signals to pass through, and then transmit them to the A / D signal converter 7. The A / D signal converter 7 converts the voltage and current analog signals into digital signals and transmits them to the controller 1. The controller 1 calculates and processes the obtained voltage and current data to obtain the resistivity value, and the measurement results are displayed on the LED screen.

[0043] Soil resistivity is calculated using the following formula:

[0044]

[0045] ρ——soil resistivity (Ω·m),

[0046] a——the distance between the two electrodes (m),

[0047] U is the voltage V between the second annular electrode 14 and the third annular electrode 18,

[0048] I is the current A between the second annular electrode 14 and the third annular electrode 18 .

[0049] After measuring the soil resistivity, the stepper motor 2 is powered on, driving the housing and the shear plate 21 to rotate clockwise, and the extension rod 6 is also connected to rotate clockwise, and the overall rotation will not affect the connection between the extension rods 6. Then, the torque sensor 3 connected to the stepper motor 2 reads the data and transmits it to the ground controller 1, and the shear strength of the soil is calculated and displayed on the LED screen. The height of the shear plate 21 is H, and the diameter of the head of the shear plate 21 is D.

[0050] The shear strength of undisturbed soil is calculated using the following formula:

[0051] C u =10K'ξR y ,

[0052]

[0053] C u ——original soil shear strength (kPa),

[0054] K'——Constant related to the size of the shear plate head (cm -3 ),

[0055] D——diameter of shear plate head (cm),

[0056] H——Height of shear plate head (cm),

[0057] ξ——Calibration coefficient of shear plate head sensor,

[0058] R y ——The strain reading of the original soil at shear failure (μ ε ).

[0059] The outside of the soil sampling tube 26 is coated with insulating paint 16, and the top threaded design is used to connect with the upper end of the inner shell. Symmetrical bolts I27 and bolts II28 are arranged at the bottom of the soil sampling tube 26. When the soil sampling tube 26 is sent to the laboratory, it can be split and disassembled. This method is also conducive to less disturbance of the soil sample and better obtaining the parameters of the soil body.

[0060] The present invention integrates the resistivity in-situ test technology and the shear strength in-situ test on a soil sampler. The present invention has the functions of synchronously testing the soil resistivity, soil strength and soil sampling. The present invention facilitates the in-situ measurement of the resistivity of the soil layer on site and effectively improves the accuracy of the resistivity measurement.

[0061] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multifunctional original soil extractor, characterized in that: It includes a soil sampling system, a resistivity test system, a soil strength test system, a housing and a controller (1); The soil sampling system comprises a soil sampling pipe (26); the soil sampling pipe (26) is arranged in the housing; The resistivity testing system is provided with a plurality of annular electrodes, and the plurality of annular electrodes are installed on the inner wall of the housing from top to bottom through an insulating plastic layer (20); the resistivity testing system is connected to a controller (1); The soil strength testing system comprises a stepper motor (2), a torque sensor (3) and a shear mechanism; the stepper motor (2) is connected to the upper part of the housing, the shear mechanism is mounted on the housing, and the torque sensor (3) is connected to the stepper motor (2) and the controller (1) respectively; The resistivity testing system comprises a first annular electrode (11), a second annular electrode (14), a third annular electrode (18) and a fourth annular electrode (19); the first annular electrode (11), the second annular electrode (14), the third annular electrode (18) and the fourth annular electrode (19) are sequentially mounted on the inner wall of the housing from top to bottom through an insulating plastic layer (20); The shell is provided with a hollow interlayer (15); a circuit (5) and a signal processing system are provided in the hollow interlayer (15); the signal processing system is connected to the resistivity test system and the controller (1) via the circuit (5); The signal processing system comprises an A / D signal converter (7), a current filter (10), a voltage filter (12) and a voltage amplifier (13); The first annular electrode (11), the fourth annular electrode (19), the current amplifier (17) and the current filter (10) are connected in series, and the second annular electrode (14), the third annular electrode (18), the voltage amplifier (13) and the voltage filter (12) are connected in series; the two series circuits are connected in parallel and the current signal is converted into a digital signal through an A / D signal converter (7) and sent to the controller (1); the distances between adjacent annular electrodes are equal.

2. The multifunctional original soil sampler according to claim 1, characterized in that: The shearing mechanism comprises four shearing plates (21); the four shearing plates (21) are arranged on the housing in pairs opposite to each other.

3. The multifunctional original soil sampler according to claim 1, characterized in that: The stepping motor (2) is connected to the upper part of the housing via an extension rod (6).

4. The multifunctional original soil extractor according to claim 3 is characterized in that: It also includes a hydraulic device (4); the hydraulic device (4) is installed on the extension rod (6).

5. The multifunctional original soil extractor according to claim 1, characterized in that: A drainage channel (8) is provided on the upper part of the outer shell; a ball valve (9) is provided in the drainage channel (8); one end of the drainage channel (8) is connected to the soil extraction pipe (26), and the other end is connected to the outside.

6. The multifunctional original soil sampler according to claim 1, characterized in that: The soil taking pipe (26) can be opened left and right.

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