A method for detecting soil compaction degree based on the response surface method
Through the soil compaction detection method based on the response surface method, a second-order response surface model of soil dielectric constant, conductivity, maximum penetration resistance, mass moisture content and dry density was established. Combined with the particle swarm optimization algorithm, a fast, non-destructive and accurate soil mass moisture content and dry density measurement was achieved, solving the problems of low accuracy and poor applicability in traditional detection methods.
Patent Information
- Application Number
- CN202211152176.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-21
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2042-09-21
AI Technical Summary
In the prior art, traditional detection methods have problems such as lossy, slow speed, high cost, few sampling points and low accuracy for soil mass moisture content and dry density. The one-step method based on dielectric constant and conductivity is poor in different types of soils, making it difficult to meet the needs of rapid mechanized construction.
The soil compaction detection method based on the response surface method is adopted. By establishing a second-order response surface model of soil dielectric constant, conductivity, maximum penetration resistance, mass moisture content and dry density, combined with a particle swarm optimization algorithm, a portable detection device is formed using an FDR sensor and penetration instrument to perform rapid non-destructive testing.
It improves the accuracy and efficiency of soil compaction detection, overcomes the shortcomings of traditional detection methods, is suitable for different types of soil, and achieves fast, non-destructive and accurate soil mass moisture content and dry density measurement.
Smart Images
Figure CN115455712B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of rapid detection of moisture content and dry density of filled soil, and specifically to a method for detecting soil compaction degree based on the response surface method. Background Technique
[0002] Soil materials are widely used in the construction of infrastructure such as water conservancy, transportation, and municipal engineering. For example, in water conservancy projects, they are often used as filling materials for water retaining structures such as earth dams, core walls, and levees. Compaction degree is one of the most critical indicators in the construction management of filling projects, directly related to the strength, deformation, and stability of filling projects. Among them, mass moisture content and dry density are two key parameters for determining compaction degree. The traditional detection methods are as follows: for the mass moisture content of soil, the drying method is adopted, and for the dry density of soil, the cutting ring method, sand replacement method, water replacement method, etc. are usually combined with the drying method for determination; although the test results of these traditional detection methods are accurate and reliable, they are destructive tests, and there are disadvantages such as few sampling points, slow detection speed, high cost, and large interference to construction, making it difficult to meet the requirements of current rapid mechanized construction; therefore, the engineering community has been looking for rapid non-destructive and high-precision rapid test methods for soil mass moisture content and dry density to improve the detection efficiency of soil compaction degree.
[0003] Currently, there is a one-step detection method based on time domain reflectometry (TDR) or frequency domain reflectometry (FDR) for rapid non-destructive detection of soil compaction degree (Chen Yun, Chen Wei, Chen Renpeng, etc. Design and application of sensors for joint monitoring of soil moisture content and dry density by TDR [J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(2): 418-426.). This method mainly linearly fits the soil dielectric constant, conductivity with moisture content and dry density once, and then derives the calculation formulas for moisture content and dry density.
[0004] Since this one-step detection method does not consider the quadratic effect and interaction effect of moisture content and dry density on soil dielectric constant and conductivity, and the measured dielectric constant value is difficult to comprehensively reflect the influence of moisture content and dry density, resulting in low accuracy of the measured soil mass moisture content and dry density, making it inapplicable to different engineering filled soils and difficult to accurately evaluate the soil compaction degree of the soil after on-site rolling. Therefore, we propose a method for detecting soil compaction degree based on the response surface method. Summary of the Invention
[0005] To solve the problems existing in the prior art, the present invention provides a method for detecting soil compaction degree based on the response surface method.
[0006] To achieve the above object, the scheme adopted by the present invention is as follows:
[0007] A method for detecting soil compaction degree based on the response surface method, comprising the following steps:
[0008] S1: Take part of the in-situ soil to conduct in-door calibration experiments, prepare specimens with different water contents and dry densities, use FDR sensors to measure the dielectric constant and conductivity of the soil, and use a penetrometer to measure the maximum penetration resistance of the soil;
[0009] S2: Take the dielectric constant, conductivity and maximum penetration resistance of the soil as response targets, the water content and dry density of the soil as influencing factors, consider the linear effect, quadratic effect and interaction effect, and establish a second-order response surface model for the variation of the dielectric constant, conductivity and maximum penetration resistance of the soil with the mass water content and dry density;
[0010] S3: According to the correlation between the conductivity and dielectric constant of the soil, establish a correction model for the conductivity of the soil;
[0011] S4: Connect the FDR sensor, penetrometer with an electric reaction lifting device to form a set of portable rapid detection device. Control the lifting by a motor, insert the probes of the FDR sensor and penetrometer into the compacted soil, measure the measured dielectric constant and measured maximum penetration resistance of the compacted soil respectively, and substitute the measured dielectric constant into the correction model of the soil conductivity to calculate the corrected value of the soil conductivity;
[0012] S5: Take the measured dielectric constant, corrected value of conductivity and measured maximum penetration resistance as known quantities, substitute them into the corresponding second-order response surface model, take the minimum root mean square error between the measured values and the model calculated values of the three target values as the objective function, and inversely obtain the optimal set of calculation parameters based on the particle swarm optimization algorithm, which are the mass water content and dry density of the in-situ compacted soil.
[0013] As a preferred technical solution:
[0014] For a method for detecting soil compaction degree based on the response surface method as described above, in step S2, the expression of the second-order response surface model for the variation of the dielectric constant, conductivity and maximum penetration resistance of the soil with the mass water content and dry density is as follows:
[0015]
[0016] In the formula, , , are the response surface functions of the dielectric constant, conductivity and maximum penetration resistance of the soil respectively; , , are truncation coefficients, , , , , , are linear term coefficients, , , is the interaction term coefficient, , , , , , are the quadratic term coefficients. All coefficients are the fitting parameters of the model by the least squares method and are determined by the calibration test fitting; is the moisture content of the soil mass, is the dry density.
[0017] For the soil compaction degree detection method based on the response surface method as described above, the soil conductivity correction model in step S3 adopts the following function:
[0018]
[0019] In the formula, , , , are the model parameters, is the conductivity correction value, is the dielectric constant.
[0020] For the soil compaction degree detection method based on the response surface method as described above, in step S5, the measured dielectric constant, conductivity correction value, and measured maximum penetration resistance are selected as known quantities, and the objective function is constructed by the equal weight method:
[0021]
[0022] In the formula, is the measured dielectric constant, is the conductivity correction value, and P is the measured maximum penetration resistance; , and are the response surface functions corresponding to the dielectric constant, conductivity, and maximum penetration resistance of the soil.
[0023] For the soil compaction degree detection method based on the response surface method as described above, in step S4, the FDR sensor and the penetrometer are detachably connected to the bottom of the force transfer rod of the electric reaction lifting device. During on-site detection, first connect the penetrometer to measure the maximum penetration resistance, and then connect the FDR sensor to measure the dielectric constant. The values are all recorded in the data collector; during the test, the penetration speed of the probe is controlled by the motor;
[0024] Among them, the FDR sensor includes a circuit board, an external threaded column of the FDR sensor arranged above the circuit board, an FDR probe arranged below the circuit board, and an FDR sensor data transmission wire connected to the circuit board; the penetrometer includes a load sensor, an external threaded column of the penetrometer arranged above the load sensor, a micro probe arranged below the load sensor, and a penetrometer data transmission wire connected to the load sensor; the electric reaction force lifting device includes a bottom plate and a support plate parallel to the bottom plate. A foot pedal is arranged on each side of the bottom plate. The bottom plate and the support plate are fixedly connected by 4 support screws. A circular through hole is formed in the middle of the bottom plate to allow the FDR sensor and the penetrometer to pass through. A force transmission rod is vertically arranged through the support plate. A threaded hole adapted to the external threaded column of the FDR sensor and the external threaded column of the penetrometer is axially formed inside the force transmission rod. A lifting transmission device is arranged at one end of the force transmission rod away from the circular through hole. The lifting transmission device is fixed on the support plate, and a motor is arranged on one side. The motor is connected to the collector through a collector data transmission wire, and the motor is connected to a power supply.
[0025] The principle of the present invention is as follows:
[0026] First, take the in-situ test soil body to carry out an indoor calibration test, study the relationships between the dielectric constant, conductivity, and maximum penetration resistance of the soil body and the mass moisture content and dry density, consider the linear effect, quadratic effect, and interaction effect, establish a second-order response surface model for the changes of the dielectric constant, conductivity, and maximum penetration resistance of the soil body with the mass moisture content and dry density, and determine the corresponding model parameters by least square fitting. At the same time, study the correlation between the conductivity and dielectric constant of the soil body and establish a correction model for the conductivity of the soil body; secondly, fix the FDR sensor and the penetrometer to the electric reaction force lifting device through threaded connections to form a set of portable rapid detection equipment, measure the measured dielectric constant and measured maximum penetration resistance of the on-site compacted soil body, and calculate the conductivity correction value using the measured dielectric constant; then, substitute the measured dielectric constant, measured maximum penetration resistance, and conductivity correction value into the second-order response surface model to establish an objective function with the minimum root mean square error of the measured value and the calculated value; finally, use the particle swarm optimization algorithm for inversion to obtain the mass moisture content and dry density of the soil body and calculate the degree of soil compaction.
[0027] The present invention provides a method for detecting the degree of soil compaction based on the response surface method, which has the following beneficial effects:
[0028] Firstly, undisturbed soil samples from in-situ tests are taken to conduct laboratory calibration tests to study the relationships between the dielectric constant, electrical conductivity, and maximum penetration resistance of the soil and the mass water content and dry density. A second-order response surface model for the variation of the soil dielectric constant, electrical conductivity, and maximum penetration resistance with the mass water content and dry density is established, and the model parameters of the response are determined. At the same time, the correlation between the soil electrical conductivity and dielectric constant is studied, and a correction model for the soil electrical conductivity is established to overcome the problem of the inconsistency between the electrical conductivity of the pore water detected in-situ and that of the pore water in the laboratory calibration tests.
[0029] The measured dielectric constant, measured maximum penetration resistance, and the corrected value of the electrical conductivity are substituted into the second-order response surface model. An objective function is established with the minimum root mean square error between the measured values and the calculated values, and the particle swarm optimization algorithm is used for inversion to obtain the soil mass water content and dry density, and the degree of compaction is given. This method adds the detection of the maximum penetration resistance on the basis of the original one-step method, and considers the quadratic effects and interaction effects of the water content and dry density on the dielectric constant, electrical conductivity, and maximum penetration resistance. The established second-order response surface model can basically be applied to all types of soils, and the accuracy of the predicted soil mass water content and dry density is greatly improved.
[0030] The measured soil dielectric constant and measured maximum penetration resistance can be quickly measured with the assistance of an electric reaction lifting device, which can effectively improve the detection efficiency of the soil compaction degree, thus alleviating the practical contradiction between the detection of the filling construction quality and the rapid mechanized construction.
[0031] The present invention effectively overcomes the disadvantages of traditional destructive testing methods for compaction degree, such as few sampling points, slow detection speed, high cost, and large interference with construction. At the same time, it overcomes the problems of poor applicability and low testing accuracy of the one-step method based on the dielectric constant and electrical conductivity tests in different types of soils, and greatly improves the detection efficiency and detection accuracy of the soil compaction degree. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 is the flow chart of the soil compaction degree detection method based on the response surface method of the present invention;
[0033] Figure 2 is the schematic diagram of the electric reaction lifting device in the present invention;
[0034] Figure 3 is the schematic diagram of the FDR sensor of the present invention;
[0035] Figure 4 is the schematic diagram of the penetrometer of the present invention;
[0036] Figure 5 is the dielectric constant response surface diagram of the present invention;
[0037] Figure 6Conductivity response surface diagram of the present invention;
[0038] Figure 7 Penetration resistance response surface diagram of the present invention;
[0039] In the figure: 2-1, foot pedal; 2-2, bottom plate; 2-3, support screw; 2-4, force transmission rod; 2-5, support plate; 2-6, lifting transmission device; 2-7, motor; 2-8, data transmission wire of the collector; 2-9, collector; 2-10, internal thread; 3-1, FDR probe; 3-2, circuit board; 3-3, external thread column of FDR sensor; 3-4, data transmission wire of FDR sensor; 3-5, micro probe; 3-6, load sensor; 3-7, data transmission wire of penetrometer; 3-8, external thread column of penetrometer. Specific embodiments
[0040] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.
[0041] Embodiment 1
[0042] A method for detecting soil compaction degree based on the response surface method, as Figure 1 shown, the specific steps are as follows:
[0043] S1: Take part of the on-site soil to conduct indoor calibration experiments, prepare specimens with different water contents and dry densities, use the FDR sensor to measure the soil dielectric constant and conductivity, and use the penetrometer to measure the maximum penetration resistance of the soil;
[0044] S2: Take the soil dielectric constant, conductivity and maximum penetration resistance as response targets, and the soil water content and dry density as influencing factors. Considering linear effects, quadratic effects and interaction effects, establish a second-order response surface model of the soil dielectric constant, conductivity and maximum penetration resistance varying with the mass water content and dry density;
[0045] Among them, the expression of the second-order response surface model of the soil dielectric constant, conductivity and maximum penetration resistance varying with the mass water content and dry density is as follows:
[0046]
[0047] In the formula, , , are the response surface functions of the soil dielectric constant, conductivity and maximum penetration resistance respectively; , , is the truncation coefficient, , , , , , are the linear term coefficients, , , are the interaction term coefficients, , , , , , are the quadratic term coefficients. Each coefficient is a fitting parameter of the model by the least squares method and is determined by calibration tests; is the moisture content of the soil mass, is the dry density;
[0048] S3: According to the correlation between the soil electrical conductivity and the dielectric constant, establish a modified model of the soil electrical conductivity;
[0049] Among them, the modified model of the soil electrical conductivity adopts the following function:
[0050]
[0051] In the formula, , , , are the model parameters, is the corrected value of the electrical conductivity, is the dielectric constant;
[0052] S4: Connect the FDR sensor, the penetrometer and the electric reaction lifting device to form a set of portable rapid detection device. Control the lifting by the motor, insert the probes of the FDR sensor and the penetrometer into the compacted soil, measure the dielectric constant and the maximum penetration resistance of the compacted soil respectively, substitute the dielectric constant into the electrical conductivity correction model, and calculate the corrected value of the soil electrical conductivity;
[0053] Among them, such as Figure 2 , Figure 3 , Figure 4As shown in the figure, the FDR sensor includes a circuit board 3-2, an external threaded column of the FDR sensor arranged above the circuit board 3-2, an FDR probe 3-1 arranged below the circuit board 3-2, and an FDR sensor data transmission wire 3-4 connected to the circuit board 3-2; the penetrometer includes a load sensor 3-6, an external threaded column 3-8 of the penetrometer arranged above the load sensor 3-6, a micro probe 3-5 arranged below the load sensor 3-6, and a penetrometer data transmission wire 3-7 connected to the load sensor 3-6; the electric reaction force lifting device includes a bottom plate 2-2 and a support plate 2-5 parallel to the bottom plate 2-2. A foot pedal 2-1 is arranged on each side of the bottom plate. The bottom plate 2-2 and the support plate 2-5 are fixedly connected by 4 support screws 2-3. A circular through hole is formed in the middle of the bottom plate 2-2 to allow the FDR sensor and the penetrometer to pass through. A force transmission rod 2-4 is vertically penetrated through the support plate 2-5. A threaded hole 2-10 adapted to the external threaded column 3-3 of the FDR sensor and the external threaded column 3-8 of the penetrometer is axially formed inside the force transmission rod 2-4. One end of the force transmission rod 2-4 far from the circular through hole is provided with a lifting transmission device 2-6. The lifting transmission device 2-6 is fixed on the support plate 2-5, and a motor 2-7 is arranged on one side. The motor 2-7 is connected to the acquisition instrument 2-9 through the acquisition instrument data transmission wire 2-8, and the motor 2-7 is connected to a power supply;
[0054] The connection of the FDR sensor, the penetrometer and the electric reaction force lifting device means that the bottom of the force transmission rod of the FDR sensor and the penetrometer are detachably connected by threads. During on-site detection, first connect the penetrometer to measure the maximum penetration resistance, and then connect the FDR sensor to measure the dielectric constant. The values are all recorded in the acquisition instrument; during the test, the penetration speed of the probe is controlled by the motor;
[0055] S5: Take the measured dielectric constant, conductivity correction value and measured maximum penetration resistance as known quantities, substitute them into the corresponding second-order response surface model, take the minimum root mean square error between the measured values and the model calculated values of the three target values as the objective function, and inversely obtain an optimal set of calculation parameters based on the particle swarm optimization algorithm, which are the mass moisture content and dry density of the on-site compacted soil;
[0056] Among them, the objective function is constructed by the equal weight method, and the objective function is:
[0057]
[0058] In the formula, is the measured dielectric constant, is the conductivity correction value, and P is the measured maximum penetration resistance; 、 and are the response surface functions corresponding to the dielectric constant, conductivity and maximum penetration resistance of the soil.
[0059] Example 2
[0060] A method for detecting soil compaction degree based on the response surface method, the specific steps are as follows:
[0061] Step 1: Dry the soil samples retrieved from the site and sieve them through a 2 mm sieve. After sieving, mix the soil with tap water to prepare soil samples with mass water contents of 14%, 16%, 18%, and 20%, and seal them for 72 hours. In an acrylic cylinder (diameter 100 mm, height 150 mm), compact the soil into soil columns with different water contents and dry densities according to the target dry density (1.3 g / cm 3 、1.4 g / cm 3 、1.5 g / cm 3 、1.6 g / cm 3 ). For each layer after compaction, use a tool to roughen the surface to reduce the delamination phenomenon between subsequent compaction layers;
[0062] Step 2: After the soil columns are prepared, first use a penetrometer to measure the maximum penetration resistance of the soil, and then use an FDR sensor to measure the dielectric constant and conductivity of the soil. During the test, keep the probe inserted at a uniform speed, and change the probe insertion position to repeat the measurement 3 - 5 times, and take the average value;
[0063] Among them, the penetrometer includes a load sensor and a micro-probe. The total length of the probe is 66 mm, the probe tip is conical with an included angle of 60°, the upper diameter of the probe tip is 3.4 mm, and the diameter of the probe rod is 3.0 mm, which is slightly smaller than the probe tip to eliminate the frictional effect between the probe rod and the side wall during penetration; The FDR sensor consists of a main body and three probes. The length of the probes is 70 mm, the diameter is 3 mm, and the spacing is 13 mm. The dielectric constant and conductivity of the soil can be measured simultaneously, and the test data of both are recorded in the data collector;
[0064] Step 3: Taking the dielectric constant, conductivity, and maximum penetration resistance of the soil as response targets, and the water content and dry density of the soil as influencing factors, considering linear effects, quadratic effects, and interaction effects, establish a second-order response surface model for the change of the dielectric constant, conductivity, and maximum penetration resistance of the soil with the mass water content and dry density:
[0065]
[0066] In the formula, 、 、 are the response surface functions of the dielectric constant, conductivity, and maximum penetration resistance of the soil respectively; 、 、 are truncation coefficients, 、 、 、 , , is the coefficient of the linear term, , , are the coefficients of the interaction terms, , , , , , are the coefficients of the quadratic terms. Each coefficient is a fitting parameter of the least squares method of the model and is determined by fitting the calibration test; is the mass water content of the soil, is the dry density. The response surface diagrams of the dielectric constant, electrical conductivity, and maximum penetration resistance are as shown in Figure 5 , Figure 6 , Figure 7 ;
[0067] Step 4: According to the correlation between the electrical conductivity and dielectric constant of the soil, establish a correction model for the electrical conductivity of the soil:
[0068]
[0069] wherein, , , , are the model parameters, is the corrected value of the electrical conductivity, is the dielectric constant;
[0070] Step 5: Connect the FDR sensor, penetrometer, and electric reaction lifting device to form a set of portable rapid detection devices. Control the lifting through the motor, insert the probes of the FDR sensor and penetrometer into the on-site compacted soil, measure the measured dielectric constant and measured maximum penetration resistance of the on-site compacted soil respectively, and substitute the measured dielectric constant into the electrical conductivity correction model to calculate the corrected value of the electrical conductivity of the on-site compacted soil;
[0071] Among them, the FDR sensor and penetrometer are detachably connected to the bottom of the force transmission rod of the electric reaction lifting device by threads. During on-site testing, first connect the penetrometer to measure the maximum penetration resistance, and then connect the FDR sensor to measure the dielectric constant and electrical conductivity. The values are all recorded in the acquisition instrument. During testing, control the penetration speed of the probe through the motor;
[0072] Step 6: Take the measured dielectric constant, corrected value of electrical conductivity, and measured maximum penetration resistance as known quantities, substitute them into the corresponding second-order response surface model, and construct an objective function using the equal weight method with the principle of minimizing the root mean square error of the measured and calculated values of the three target values:
[0073]
[0074] In the formula, is the measured dielectric constant, is the conductivity correction value, and P is the measured maximum penetration resistance; , and are the response surface functions corresponding to the dielectric constant, conductivity, and maximum penetration resistance of the soil mass. Then, based on the particle swarm optimization algorithm, an optimal set of calculation parameters is inversely obtained, which is the mass moisture content and dry density of the on-site compacted soil mass;
[0075] Among them, in steps 5 and 6: after the on-site data collection is completed, undisturbed soil samples can be taken at the probe insertion site, and the actual mass moisture content and dry density of the soil mass can be measured by combining the undisturbed soil sampling method and the oven drying method. Then, the mass moisture content and dry density obtained by inverting using the method proposed in this paper can be compared with the mass moisture content and dry density measured by combining the undisturbed soil sampling method and the oven drying method;
[0076] Each soil sample and soil column are detected twice, and the measured data are shown in Tables 1 and 2. From the test results, it can be seen that the soil compaction degree detection method based on the response surface method in the present invention is more accurate for the test results of soil compaction degree compared with the traditional undisturbed soil sampling method and oven drying method, and is applicable to different engineering filling soil masses.
Claims
1. A method for detecting soil compaction degree based on the response surface method, characterized in that, It includes the following steps: S1: Take some on-site soil to conduct indoor calibration experiments, prepare specimens with different water contents and dry densities, use the FDR sensor to measure the dielectric constant and conductivity of the soil, and use the penetrometer to measure the maximum penetration resistance of the soil; S2: Take the dielectric constant, conductivity and maximum penetration resistance of the soil as response targets, and the water content and dry density of the soil as influencing factors. Considering the linear effect, quadratic effect and interaction effect, establish a second-order response surface model for the variation of the dielectric constant, conductivity and maximum penetration resistance of the soil with the mass water content and dry density; S3: According to the correlation between the conductivity and dielectric constant of the soil, establish a correction model for the soil conductivity; S4: Connect the FDR sensor, penetrometer and electric reaction lifting device to form a set of portable rapid detection device. Control the lifting by the motor, insert the probes of the FDR sensor and penetrometer into the compacted soil, measure the measured dielectric constant and measured maximum penetration resistance of the compacted soil respectively, and substitute the measured dielectric constant into the correction model of the soil conductivity to calculate the corrected value of the soil conductivity; S5: Take the measured dielectric constant, corrected value of conductivity and measured maximum penetration resistance as known quantities, substitute them into the corresponding second-order response surface model, and take the minimum root mean square error between the measured values and the model calculated values of the three target values as the objective function, and inversely obtain the optimal set of calculation parameters based on the particle swarm optimization algorithm, which are the mass water content and dry density of the on-site compacted soil; In step S2, the expression of the second-order response surface model for the variation of the dielectric constant, conductivity and maximum penetration resistance of the soil with the mass water content and dry density is as follows: In the formula, , , are the response surface functions of the dielectric constant, conductivity, and maximum penetration resistance of the soil mass, respectively; , , are truncation coefficients, , , , , , are linear term coefficients, , , are interaction term coefficients, , , , , , are quadratic term coefficients. All coefficients are fitting parameters of the model by the least squares method and are determined by calibration tests; is the mass water content of the soil mass, is the dry density; The correction model of the soil conductivity in step S3 adopts the following function: In the formula, , , , are model parameters, is the conductivity correction value, is the dielectric constant.
2. The soil compaction degree detection method based on the response surface method according to claim 1, characterized in that, In step S5, select the measured dielectric constant, corrected value of conductivity and measured maximum penetration resistance as known quantities, and construct the objective function by the equal weight method: In the formula, is the measured dielectric constant, is the conductivity correction value, and P is the measured maximum penetration resistance; , and are the response surface functions corresponding to the dielectric constant, conductivity, and maximum penetration resistance of the soil mass.
3. A method for detecting the soil compaction degree based on the response surface method according to claim 1, characterized in that, In step S4, the bottom of the force transmission rod of the FDR sensor and penetrometer and the electric reaction lifting device are connected by a detachable thread. During on-site detection, first connect the penetrometer to measure the maximum penetration resistance, and then connect the FDR sensor to measure the dielectric constant. The values are all recorded in the acquisition instrument; during testing, control the penetration speed of the probe by the motor.