Highway subgrade compaction quality detection vehicle and detection method

Abstract

The invention discloses a highway subgrade compaction quality detection vehicle and a detection method, the detection vehicle comprises a vehicle body, a test wheel combination, a traction head and a loading table, the test wheel combination is rotatably arranged at the lower part of the vehicle body, the traction head is fixedly arranged at one end or two ends of the vehicle body, a resistance strain gauge for measuring traction force is arranged on the traction head, and the loading table is fixedly arranged at the upper part of the vehicle body; when the compaction quality of the highway subgrade is detected, a standard load is arranged at the upper part of the loading table, the detection vehicle is dragged by the tractor to pass through the highway subgrade to be detected, and the compaction quality of the highway subgrade is judged according to the change of traction force; the detection vehicle has the advantages of being simple and reliable in structure, low in price, high in detection efficiency and independent of experience of detection personnel in the detection process, is used for detecting the compaction quality of the highway subgrade, and solves the problem that the detection data is lack of accuracy and objectivity due to the non-uniform standard of a vibratory roller and the problem of experience of the detection personnel in the existing compaction settlement difference method.

Description

Technical Field

[0001] The invention relates to the technical field of highway roadbed detection, and in particular to a highway roadbed compaction quality detection vehicle and a detection method. Background Art

[0002] The compaction quality of the highway subgrade has a great impact on the strength, stability and bearing capacity of the subgrade. Good compaction quality of the highway subgrade will prevent the subgrade filler from settling and deforming when vehicles are driving, ensure the stability of vehicle driving, and make the subgrade have sufficient mechanical strength and stability to resist the vehicle load.

[0003] In the "Highway Roadbed and Pavement Field Test Regulations" JTG 3450-2019, several highway roadbed compaction quality detection methods are recommended, including the pit digging and sand filling method, the nuclear density and moisture meter method, the ring knife method, and the compaction settlement difference method. Among them, the pit digging and sand filling method seems quite simple on the surface, but in actual operation, it requires extremely high experience of the test personnel and is prone to large errors. As the basis for the quality of roadbed compaction, it often leads to disputes between the quality inspection unit and the construction unit over the test results. This method will damage the existing roadbed, and the detection process needs to be tested point by point, so the detection efficiency is extremely low. Among them, the nuclear density and moisture meter method is a high-accuracy highway roadbed compaction quality detection method, but this method has radioactive hazards, and the detection process also needs to be tested point by point. The detection efficiency is not high, and the nuclear instrument has high requirements for use and preservation. In recent years, most domestic testing units have stopped using it. The knife ring method will disturb some fine-grained soil inside the knife ring during the detection of dry density of the roadbed on site, resulting in inaccurate test results. This method also has the problem of point-by-point detection, resulting in low detection efficiency.

[0004] Among them, the compaction settlement difference method is a dual-control test method combined with the highway roadbed construction process parameters. The stability of the settlement deformation of the road section to be tested is detected by a vibratory roller to characterize the compaction degree of the highway roadbed. The detection process is a point detection of several observation sections. The detection process is continuous and will not cause damage to the existing roadbed. Therefore, the detection efficiency is relatively high. With the continuous improvement of the equipment level of large-scale domestic highway construction, more and more highway construction projects tend to use the compaction settlement difference method to detect the compaction quality of a large amount of stone roadbed or soil-rock mixed roadbed. However, the current compaction settlement difference method has the following problems: the detection process requires the use of a vibratory roller, and the vibratory roller manufacturers used by various construction units during the construction process are If the vibratory roller used by the construction unit during the construction process is used, the test standards of the compaction-settlement difference method will be inconsistent. At the same time, the test results of this method will be more dependent on construction experience, which will affect the accuracy and objectivity of the test results of the compaction-settlement difference method. In addition, the existing compaction-settlement difference method test process is relatively cumbersome, and it is necessary to set up several settlement observation points in several observation sections, and each observation point needs to be equipped with a fixed object. The test process also requires elevation measurement of each observation point (for the specific test process, see "Highway Roadbed and Pavement Field Test Regulations" pages 41-43). Therefore, the test process is cumbersome and the operation is complicated, which also affects the further improvement of the test efficiency of the compaction-settlement difference method.

[0005] Therefore, how to provide a simple, reliable, low-cost standard testing equipment that does not rely on the experience of testers based on the existing compaction settlement difference method is of great practical significance for simplifying the testing process, improving testing efficiency, and ensuring the accuracy and objectivity of the test results. Summary of the invention

[0006] In order to overcome the shortcomings in the background technology, the present invention discloses a highway roadbed compaction quality inspection vehicle and inspection method. The inspection vehicle with a standard load applied to it is towed by a tractor to pass over the roadbed to be inspected, and the compaction quality of the highway roadbed is judged by the change in the traction force, so as to solve the problems of inconsistent standards, cumbersome inspection process, and lack of accuracy and objectivity in the existing compaction settlement difference method.

[0007] In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical scheme: a highway roadbed compaction quality inspection vehicle, including a vehicle body, a test wheel assembly, a traction head, and a loading platform, wherein the test wheel assembly is rotatably arranged at the lower part of the vehicle body, the traction head is fixedly arranged at one end or both ends of the vehicle body, the loading platform is fixedly arranged at the upper part of the vehicle body, and a loading plate is arranged on the upper part of the loading platform; when conducting a highway roadbed compaction quality inspection, the inspection vehicle is towed by a traction vehicle to pass over the roadbed to be inspected twice, and the highway roadbed compaction quality is judged by comparing the difference between the two traction forces with the standard value.

[0008] Furthermore, the test wheel assembly includes a test wheel and a test wheel shaft, and the test wheel and the test wheel shaft are rotatably connected via bearings; both ends of the test wheel shaft are fixedly arranged on the lower part of the vehicle body via test wheel brackets.

[0009] Furthermore, the traction head is arranged at a height equal to the test wheel axis.

[0010] Furthermore, a resistance strain gauge is fixedly attached to the traction head; a data collector is arranged on the vehicle body; the resistance strain gauge is electrically connected to the data collector, and the data collector is communicatively connected to the data processing device.

[0011] Furthermore, a separation groove is provided in the middle of the outer circumferential surface of the test wheel, and the separation groove separates the outer circumferential surface of the test wheel into symmetrical test wheel flanges.

[0012] Furthermore, a camera is provided in the data collector.

[0013] Preferably, a highway subgrade compaction quality inspection vehicle is composed of two inspection vehicles connected in series by a connecting shaft through a traction head arranged at the end, forming a two-stage series inspection vehicle; when conducting a highway subgrade compaction quality inspection, the two series-connected inspection vehicles are towed by a traction vehicle and pass over the subgrade to be inspected at one time, and the highway subgrade compaction quality is judged by comparing the difference in traction force of the two inspection vehicles with a standard value.

[0014] Furthermore, a magnetorheological fluid damper is arranged between the test wheel and the test wheel shaft; two magnetorheological fluid dampers are provided, which are symmetrically arranged on both sides of the test wheel; the magnetorheological fluid damper is electrically connected to the data collector, and the working current of the magnetorheological fluid damper can be adjusted and controlled by the data collector to control the damping force of the magnetorheological fluid damper.

[0015] A method for testing the quality of roadbed compaction by a roadbed compaction testing vehicle, the steps of which are as follows: S9.1. Preparation before testing: Set a loading plate of standard weight on the loading platform of the testing vehicle; use lime powder or chalk to mark the starting and ending positions of the road surface to be tested; connect the testing vehicle to the rear end of the tractor through one end of the tractor; park the tractor 10-20 meters in front of the starting position of the road section to be tested; the standard weight of the loading plate is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width (m) of the test wheel (2.1); D is the maximum diameter of the test wheel (2.1); K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the test vehicle itself; this formula is obtained by converting the linear load q = G / L formula of the compacting wheel of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd = K*q / D; where K is a dimensionless empirical coefficient, and its specific value in actual testing needs to be determined based on experiments; S9.2, first detection: start the tractor 9, and the tractor 9 drives along the road to be detected at a set speed of 2-4 km / h; when the camera in the data collector 7 captures the marking line of the starting position of the detection section, the data collector 7 collects data from the resistance strain gauge 4.4 at a set frequency and transmits it to the data processing device for storage; when the camera in the data collector 7 captures the marking line of the end position of the detection section, the data collection ends; S9.3, second test: park the tractor 9 again 10-20 meters before the starting position of the road section to be tested; start the tractor 9, and the tractor 9 drives along the first driving track of the test section at a set speed of 2-4 km / h; when the camera in the data collector 7 captures the marking line of the starting position of the test section, the data collector 7 collects data from the resistance strain gauge 4.4 at a set frequency, and transmits the data to the data processing device for storage; S9.4. Data processing: S9.4.1. Process the data of the resistance strain gauge 4.4 collected during the two tests and convert them into the traction force of the tractor 9 on the test vehicle during the two tests; fit the traction force data of the two tests into two traction force change curves FL along the test section, and perform filtering and smoothing processing; merge the two traction force change curves FL after smoothing processing into the same traction force change curve FL coordinate system; S9.4.2. Determine the compaction quality of the tested road section according to formula (2): F1-F2≥S …… (2) In formula (2), F1 is the traction value of the first detection at a certain point on the detection section; F2 is the traction value of the second detection at a certain point on the detection section (corresponding to the point of the first detection on the detection section); S is the set judgment standard value, which is determined by actual test data; When F1-F2 is greater than or equal to the judgment standard value S, it is determined that the compaction quality of the corresponding point of the detected section does not meet the standard.

[0016] Preferably, a method for detecting the quality of roadbed compaction by a roadbed compaction detection vehicle comprises the following specific steps: S10.1. Preparation before testing: calibrate the initial traction of the two-stage tandem test vehicle to make the initial traction of the two test vehicles equal; set up loading plates of the same standard weight on the loading platforms of the two-stage tandem test vehicles; use lime powder or chalk to mark the starting and ending positions of the road surface to be tested; the two-stage tandem test vehicle is connected to the rear end of the tractor through one end of the tractor; the tractor is parked 10-20 meters in front of the starting position of the road section to be tested; the standard weight of the loading plate is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width (m) of the test wheel (2.1); D is the maximum diameter of the test wheel (2.1); K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the test vehicle itself; this formula is obtained by converting the linear load q = G / L formula of the compacting wheel of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd = K*q / D; where K is a dimensionless empirical coefficient, and its specific value in actual testing needs to be determined based on experiments; S10.2, Inspection: Start the tractor, and drive it along the road to be inspected at a set speed of 2-4 km / h; when the camera in the data collector on the inspection vehicle adjacent to the tractor captures the marking line of the starting position of the inspection section, the data collectors on the two inspection vehicles synchronously collect the output data of the resistance strain gauge on the traction head at the front end of the corresponding inspection vehicle at the set frequency, and transmit it to the data processing device for storage; when the camera in the data collector on the inspection vehicle far away from the tractor captures the marking line of the end position of the inspection section, the data collectors on the two inspection vehicles end data collection; S10.3. Data processing: S10.3.1. Process the resistance strain gauge data collected by the two data collectors and convert them into the traction of the two test vehicles; fit the traction data of the two test vehicles into two traction change curves fL respectively, and perform filtering and smoothing processing; merge the two traction change curves fL after smoothing processing into the same traction change curve fL coordinate system; translate the second traction change curve f2-L to the left by △L, so that the two traction change curves fL are synchronized in the same traction change curve coordinate system, that is, the positions of the test sections are ensured to be the same; where △L is the distance between the test wheels of the two test vehicles; S10.3.2. Determine the compaction quality of the tested road section according to formula (3): (f1-f2')-f2≥S......(3) In formula (3), f1 is the traction value detected by the first test vehicle at a certain point on the test section; f2 is the traction value detected by the second test vehicle at a certain point on the test section (the two test vehicles are at the same corresponding point on the test section); f2' is the average traction value of the second test vehicle on the entire test section; S is the set judgment standard value, which is determined by the actual test data; When (f1-f2')-f2 is greater than or equal to the judgment standard value S, it is determined that the corresponding point of the detected section has a compaction quality defect that does not meet the standard.

[0017] Due to the adoption of the technical scheme as described above, the present invention has the following beneficial effects: a highway roadbed compaction quality inspection vehicle disclosed in the present invention comprises a vehicle body, a test wheel assembly, a traction head, and a loading platform, wherein the test wheel assembly is rotatably arranged at the lower part of the vehicle body, the traction head is fixedly arranged at one end or both ends of the vehicle body, a resistance strain gauge for measuring traction force is arranged on the traction head, and the loading platform is fixedly arranged at the upper part of the vehicle body; when the highway roadbed compaction quality inspection is performed, a standard load is arranged on the upper part of the loading platform, the traction vehicle tows the inspection vehicle to pass over the roadbed to be inspected, and the compaction quality of the highway roadbed is judged by the change in the traction force; the inspection vehicle has the advantages of simple structure, reliability, low price, high inspection efficiency, and the inspection process does not rely on the experience of the inspection personnel, and is used for highway roadbed compaction quality inspection, which solves the problem that the inspection results of the existing compaction settlement difference method lack accuracy and objectivity due to the inconsistent standards and the experience problems of the inspection personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the appearance of the detection vehicle of the first embodiment; Figure 2 The schematic diagram of the vehicle body is as follows; Figure 3 This is a schematic diagram of the appearance of the test wheel assembly; Figure 4 This is a schematic diagram of the appearance of the test wheel bracket; Figure 5 This is a schematic diagram of the appearance of the traction head; Figure 6 This is a schematic diagram of the appearance of the connecting shaft; Figure 7 This is a schematic diagram of the appearance of the loading platform; Figure 8 This is a schematic diagram of the data collection process of Example 1; Fig. 9 This is a principle block diagram of the data acquisition process of Embodiment 1; Fig.10 This is a schematic diagram of the data processing process of Example 2; Fig.11 This is a schematic diagram of the appearance of the inspection vehicle of Example 3; Fig.12This is a schematic diagram of the data collection process of Example 3; Fig.13 This is a principle block diagram of the data acquisition process of Example 3; Fig.14 This is a schematic diagram of the data processing process of Example 4.

[0019] In the figure: 1. vehicle body; 2. test wheel assembly; 2.1. test wheel; 2.1.1. separation groove; 2.1.2. test wheel flange; 2.2. test wheel shaft; 3. test wheel bracket; 3.1. upper bracket; 3.2. lower bracket; 4. traction head; 4.1. traction head fixing flange; 4.2. traction ear; 4.3. traction head body; 4.4. resistance strain gauge; 5. connecting shaft; 5.1. flattened surface; 5.2. hinge hole; 6. loading platform; 6.1. bottom plate; 6.2. loading plate guide column; 7. data acquisition device; 8. loading plate; 9. traction vehicle; 10. magnetorheological fluid damper. DETAILED DESCRIPTION

[0020] The present invention can be explained in detail by the following examples, and the purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0021] Embodiment 1, see the attached specification Figure 1-7 : See the instruction manual Figure 1 , a highway roadbed compaction quality inspection vehicle, including a vehicle body 1, a test wheel assembly 2, a traction head 4, a loading platform 6, and a data collector 7; see the attached manual Figure 2 The vehicle body 1 is a frame structure formed by welding of steel sections; see the attached manual Figure 3 The test wheel assembly 2 includes a test wheel 2.1 and a test wheel shaft 2.2. The test wheel 2.1 is rotatably connected to the test wheel shaft 2.2 via a bearing, wherein the test wheel 2.1 has a width of 0.8 m and a diameter of 1.0 m. A separation groove 2.1.1 with a width of 0.4 m is provided in the middle of the outer cylindrical surface of the test wheel 2.1. The separation groove 2.1.1 separates the outer cylindrical surface of the test wheel 2.1 into symmetrical test wheel flanges 2.1.2. Each test wheel flange 2.1.2 has a width of 0.2 m. The total width of the two test wheel flanges 2.1.2 is 0.4 m, which is the effective width l of the test wheel 2.1. In the design of the test wheel 2.1, a total width of 0.8m is adopted to ensure that the test vehicle maintains horizontal stability during the walking process and prevent the test vehicle from horizontally tipping over. The separation groove 2.1.1 with a width of 0.4m is set on the outer circumference to reduce the effective width of the test wheel 2.1. When loading the loading plate 8 with a smaller weight, a larger test load q can be obtained, thereby achieving the purpose of reducing the total weight of the test vehicle; in addition, the width of the test wheel 2.1 of 0.8m is smaller than the wheelbase of the tractor, so as to avoid the tractor wheels pressing on the test path and having an adverse effect on the test results; see the attached manual Figure 4 The test wheel bracket 3 includes an upper bracket 3.1 and a lower bracket 3.2. The upper bracket 3.1 is fixedly arranged at the lower part of the vehicle body 1. The two ends of the test wheel shaft 2.2 are fixedly arranged at the lower part of the vehicle body 1 through the upper bracket 3.1 and the lower bracket 3.2; see the attached manual Figure 5 The traction head 4 includes a traction head fixing flange 4.1, a traction ear 4.2, a traction head body 4.3, and a resistance strain gauge 4.4. The traction head body 4.3 is a hollow short circular shaft. The traction head fixing flange 4.1 is fixedly arranged at one end of the traction head body 4.3, and the traction ear 4.2 is fixedly arranged at the other end of the traction head body 4.3. The traction ear 4.2 is provided with a hinge hole. The resistance strain gauge 4.4 is bonded to the outer cylindrical surface of the traction head body 4.3, so that the traction head 4 constitutes a tension sensor. The tension sensor is related to the structural design of the traction head body 4.3 and the characteristics of the resistance strain gauge 4.4, and has its optimal working range. The resistance strain gauge 4.4 is used to collect the traction force received by the detection vehicle when working, and the traction force received by the detection vehicle should be within the optimal working range of the tension sensor as much as possible; see the attached manual Figure 1 The traction head 4 is fixedly mounted at one end or both ends of the vehicle body 1 by bolts through the traction head fixing flange 4.1. The traction head 4 is set at a height equal to the test wheel shaft 2.2. The purpose is to prevent the traction force from passing through the test wheel shaft 2.2 when the tractor 9 is towing the test vehicle, and to prevent the traction force from generating a rotational torque to cause the vehicle body 1 to rotate around the test wheel shaft 2.2, thereby causing the traction head body 4.3 to generate a non-horizontal component force, thereby affecting the accuracy of the data collected by the resistance strain gauge 4.4; the data collector 7 is fixedly mounted on the side of the vehicle body 1, and a camera is arranged in the data collector 7, and the camera faces The ground, its lens axis intersects with the axis of the test wheel shaft 2.2. The purpose of setting a camera in the data collector 7 is to shoot the detection start or end mark line set on the detection section when conducting highway roadbed compaction quality inspection, and automatically control the data collector 7 to start or end data collection of the resistance strain gauge 4.4 by shooting the detection start or end mark line; the resistance strain gauge 4.4 is connected to the data collector 7 through a wire, and the data collector 7 is connected to the data processing device through Bluetooth or a micro-power wireless communication module. The data processing device is preferably a laptop computer; see the attached manual Figure 7 The loading platform 6 includes a bottom plate 6.1 and a loading plate guide column 6.2. The loading plate guide column 6.2 is fixedly arranged in the middle of the upper part of the bottom plate 6.1. The loading platform 6 is fixedly arranged on the top of the vehicle body 1 through the bottom plate 6.1. When the inspection vehicle is working, a loading plate 8 is arranged on the loading platform 6. The loading plate 8 is disc-shaped and has a through hole in the middle. The through hole cooperates with the loading plate guide column 6.2 to prevent the loading plate 8 from falling off during the operation of the inspection vehicle. See the instruction manual Figure 8When testing the compaction quality of the highway subgrade, a loading plate 8 of standard weight is set on the upper part of the loading platform 6. The testing vehicle is towed by the tractor 9 to pass the roadbed to be tested twice. The compaction quality of the highway subgrade is judged by comparing the difference in the two traction forces with the standard value; see the attached manual Fig. 9 In this embodiment, the data acquisition process is as follows: the data collector 7 collects the data of the resistance strain gauge 4.4 through the wire, and then transmits the data to the data processing device through the Bluetooth or micro-power wireless communication module.

[0022] The working principle of the highway subgrade compaction quality inspection vehicle is explained as follows: during the highway subgrade compaction construction process, the initial subgrade filler density is low. During the compaction process of the vibratory roller, the filler with low density absorbs the vibration compaction energy and produces a large plastic deformation, and the filler density increases; as the number of compaction times of the vibratory roller increases, the filler density gradually increases further, and the absorption of vibration compaction energy decreases, and the dynamic deformation modulus (Evd) used to evaluate the subgrade compaction quality gradually increases until it reaches the design index of the highway subgrade; when the dynamic deformation modulus (Evd) reaches the design index, the inspection vehicle is under the load of the loading plate 8 loaded with the standard weight, that is, when the test wheel 2.1 passes over the road surface to be inspected under the test load q, the highway subgrade only undergoes elastic deformation, and no longer undergoes plastic deformation. Therefore, the inspection vehicle passes over the road surface to be inspected twice, and the two traction forces F1 and F2 detected are F3 and F4. F2 is equal; if the dynamic deformation modulus (Evd) of the highway pavement does not reach the design index, when the inspection vehicle passes over the road surface to be inspected for the first time under the action of the inspection load q, the highway roadbed will not only undergo elastic deformation, but also undergo greater plastic deformation (compared with the second time passing over the road surface to be inspected), and when the inspection vehicle passes over the road surface to be inspected for the second time under the action of the inspection load q, the plastic deformation becomes smaller (compared with the first time passing over the road surface to be inspected) or no longer undergoes plastic deformation, and the energy of the plastic deformation of the road surface to be inspected comes from the traction of the inspection vehicle, so the traction will change when the inspection vehicle passes over the road surface to be inspected twice, that is, the traction F1 when passing over the road surface to be inspected for the first time will be greater than the traction F2 when passing over the road surface to be inspected for the second time, and the magnitude of the two tractions will change, so the magnitude of the two traction differences can be compared with the standard value to determine whether the compaction quality of the highway roadbed meets the design index; It can be seen from the working principle of the above-mentioned highway roadbed compaction quality inspection vehicle that its inspection process has nothing to do with the manufacturer and performance of the vibratory roller used in the construction project, thus avoiding the problem of lack of accuracy and objectivity in the inspection results caused by the previous compaction settlement difference method in the highway roadbed compaction quality inspection process, where the vibratory rollers used as inspection equipment are not uniform and the entire inspection process relies on the operating experience of the inspectors.

[0023] Embodiment 2: A detection method of a highway roadbed compaction quality detection vehicle based on Embodiment 1, wherein the specific steps are as follows: S9.1. Preparation before testing: Set a loading plate 8 of standard weight on the loading platform 6 of the testing vehicle; use lime powder or chalk to make marking lines at the starting and ending positions of the road surface to be tested; the testing vehicle is connected to the rear end of the tractor 9 through a traction head 4 at one end; the tractor 9 is parked 20 meters in front of the starting position of the road section to be tested; the standard weight of the loading plate 8 is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width of the test wheel (2.1), and its length is 0.4m; D is the maximum diameter of the test wheel (2.1), and its value is 0.8m; K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the inspection vehicle itself, and its value is 5.0kN; this formula is obtained by converting the linear load q=G / L formula of the compacting wheel of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd=K*q / D; wherein K is a dimensionless empirical coefficient, and its value is related to the filler soil type and compaction process of the specific project. In the present invention, the compaction process is actually the steady driving of the inspection vehicle, which is different from the vibration compaction of the vibratory roller. There is no vibration compaction parameter, so the K value is actually only related to the filler soil type; The standard weight G (kg) of the loading plate (8) applied can be directly determined through experiments; the specific method is: firstly, the dynamic deformation modulus Evd test is performed on the road section to be tested, and when it is determined that the dynamic deformation modulus Evd of the road section to be tested reaches the design index, the test vehicle is used for testing; during the testing process of the test vehicle, the weight of the loading plate 8 is gradually increased until F1 / F2 is greater than 1.0 during the testing process, which is the standard weight G (kg) of the loading plate 8 applied; for highway subgrades using different fillers and different design standards, the standard weight (kg) of the loading plate 8 applied is not the same. With the accumulation of test data, a query table of the standard weight (kg) of the loading plate 8 can be formed. When the quality of highway subgrade compaction is actually tested, the standard weight G of the loading plate 8 of the road section to be monitored can be obtained by querying the query table of the standard weight (kg) of the loading plate 8 according to the filler used in the highway subgrade to be monitored and the design standard of the dynamic deformation modulus Evd; If the dynamic deformation modulus Evd design standard is converted into the standard weight G of the loading plate (8) through the proportionality coefficient K, the value of the proportionality coefficient K is to substitute the standard weight G (Kg) of the loading plate 8 applied in the above experimental process into the formula (1) to calculate the corresponding K value; for example, when the roadbed uses clay filler and its dynamic deformation modulus Evd design standard is 20MPa, 30MPa, and 40MPa, when the standard weight G of the loading plate 8 applied to the inspection vehicle is measured to be 20kN, 35kN, and 45kN respectively, the calculated K values ​​are: K1=Evd*l*D / G=20*0.4*0.8 / (20+5)=0.256 K2=Evd*l*D / G=30*0.4*0.8 / (35+5)=0.240 K3=Evd*l*D / G=40*0.4*0.8 / (45+5)=0.256 The above K value is basically linear, and its average value Kavg=0.251 is taken as the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd when the highway subgrade uses clay soil filler; S9.2, first detection: start the tractor 9, and the tractor 9 drives along the road to be detected at a set speed of 3km / h; when the camera in the data collector 7 captures the marking line of the starting position of the detection section, the data collector 7 collects the output data of the resistance strain gauge 4.4 at a set frequency and transmits it to the data processing device for storage; until the camera in the data collector 7 captures the marking line of the end position of the detection section, the data collection is completed; S9.3, second test: park the tractor 9 again 20 meters before the starting position of the road section to be tested; start the tractor 9, and the tractor 9 drives along the first driving track of the test section at a set speed of 3km / h, ensuring that the two driving tracks overlap; when the camera in the data collector 7 captures the marking line of the starting position of the test section, the data collector 7 collects the resistance strain gauge 4.4 at the set frequency, and transmits the data to the data processing device for storage; until the camera in the data collector 7 captures the marking line of the end position of the test section, the data collection is completed; S9.4. Data processing: S9.4.1. Process the data of the resistance strain gauge 4.4 collected during the two tests and convert them into the traction force of the tractor 9 on the test vehicle during the two tests; fit the traction force data of the two tests into two traction force change curves FL, perform filtering and smoothing processing, and eliminate high-frequency interference signals; see the attached manual Fig.10 , the two traction force change curves FL after smoothing are merged into the same traction force change curve FL coordinate system; in the traction force change curve FL coordinate system, the S axis represents the distance from the detection starting line, and the F axis represents the traction force size; S9.4.2. Determine the compaction quality of the tested road section according to formula (2): F1-F2≥S …… (2) In formula (2), F1 is the traction value of the first test at a certain point on the test section; F2 is the traction value of the second test at a certain point on the test section; S is the set judgment standard value, which is determined by actual test data; the test determination method of the judgment standard value S is as follows: during the test process, for the section where F1-F2>0, the dynamic deformation modulus Evd test is performed. When it is detected that the dynamic deformation modulus Evd does not meet the design standard, the value of F1-F2 at this time is defined as the temporary judgment standard value; as the number of tests increases, the temporary judgment standard value will gradually approach a fixed value, and finally a fixed value that the temporary judgment standard value gradually approaches is used as the judgment standard value S; In the traction force variation curve FL, the values ​​are taken at intervals of 0.5 m, and the difference between F1 and F2 is calculated using formula (2). When the difference is greater than or equal to the set judgment standard value S, it is determined that the corresponding point of the test section has a compaction quality defect that does not meet the standard. When the traction force variation curve FL is used to judge the compaction quality of the test section, the location of the compaction quality defect that does not meet the standard of the test section can be intuitively observed.

[0024] Example 3, see the attached specification Fig.11 : A highway roadbed compaction quality inspection vehicle, two inspection vehicles are connected in series by a traction head 4 arranged at the end with a connecting shaft 5, forming a two-stage series inspection vehicle, the traction head 4 and the connecting shaft 5 are articulated and connected with a gap, allowing the second inspection vehicle to float to a certain extent in the horizontal and pitch directions relative to the first inspection vehicle; see the attached manual Fig.12 When the highway subgrade compaction quality inspection vehicle of this embodiment is used to inspect the highway subgrade compaction quality, two inspection vehicles connected in series are towed by a tractor 9 and pass over the subgrade to be inspected at one time. The highway subgrade compaction quality is judged by comparing the traction difference between the two inspection vehicles with the standard value; see the attached specification Fig.13 : The data collection process of the two-stage series detection vehicle using this embodiment is as follows: after a traction test, the data of the corresponding resistance strain gauge 4.4 is correspondingly collected by the data collector 7 respectively arranged on the two detection vehicles, and then the data collector 7 respectively arranged on the two detection vehicles transmits the data to a data processing device through Bluetooth or a micro-power wireless communication module, so that the traction value of the two detection vehicles can be obtained, so the detection efficiency is greatly improved; in addition, the two-stage series detection vehicle can ensure that the driving track of the second detection vehicle overlaps, which improves the operational difficulty of ensuring the overlapping driving tracks of the two traction detection vehicles in the embodiment; In this embodiment, a magnetorheological fluid damper 10 can also be arranged between the test wheel 2.1 and the test wheel shaft 2.2; two magnetorheological fluid dampers 10 are provided, which are symmetrically arranged on both sides of the test wheel 2.1 and are electrically connected to the data collector 7; the magnetorheological fluid damper 10 can change the damping size between the test wheel 2.1 and the test wheel shaft 2.2, thereby realizing the adjustment of the initial traction of the two test vehicles.

[0025] Embodiment 4: A detection method of a highway roadbed compaction quality detection vehicle based on Embodiment 3, wherein the specific steps are as follows: S10.1. Preparation before testing: Adjust the initial traction of the two test vehicles to be equal; set the loading plates 8 of the same standard weight on the loading platform 6 of the two-stage tandem test vehicle; use lime powder or chalk to make marking lines at the starting and ending positions of the road surface to be tested; the two-stage tandem test vehicle is connected to the rear end of the tractor 9 through a traction head 4 at one end; the tractor 9 is parked 15 meters in front of the starting position of the road section to be tested; the standard weight of the loading plate 8 is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width of the test wheel 2.1, whose length is 0.4m; K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the test vehicle itself, whose value is 5.0kN; this formula is obtained by converting the linear load q=G / L formula of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd=K*q; wherein the proportional coefficient K is determined by experiment; S10.2, detection: start the tractor 9, and the tractor 9 drives along the road to be detected at a set speed of 3km / h; when the camera in the data collector 7 on the detection vehicle adjacent to the tractor 9 captures the starting position mark line of the detection section, the data collectors 7 on the two detection vehicles synchronously collect the output data of the resistance strain gauge 4.4 on the front traction head 4 of the corresponding detection vehicle at the set frequency, and transmit it to the data processing device for storage; when the camera in the data collector 7 on the detection vehicle far away from the tractor 9 captures the end position mark line of the detection section, the data collectors 7 on the two detection vehicles end data collection; S10.3. Data processing: S10.3.1. Process the data of the resistance strain gauge 4.4 collected by the two data collectors 7 and convert them into the traction of the two test vehicles; fit the traction data of the two test vehicles into two traction change curves fL respectively, and perform filtering and smoothing processing; see the attached manual Fig.14, the two traction change curves fL after smoothing are merged into the same traction change curve fL coordinate system; in this embodiment, since there is a distance difference △L between the test wheels 2.1 of the two detection vehicles arranged in front and behind, the second traction change curve f2-S needs to be translated to the left by △L, so that the two traction change curves fL are synchronized in the same traction change curve coordinate system, that is, the positions of the detection section are ensured to be the same; wherein △L is the distance between the test wheels (2.1) of the two detection vehicles; S10.3.2. Determine the compaction quality of the tested road section according to formula (3): (f1-f2')-f2≥S......(3) In formula (3), f1 is the traction value detected by the first detection vehicle at a certain point of the detection section; f2 is the traction value detected by the second detection vehicle at a certain point of the detection section; f2' is the average traction value of the second detection vehicle in the entire detection section; S is a set judgment standard value, which is determined by actual test data. In this embodiment, the test determination method of the judgment standard value S is different from that in the first embodiment: during the detection process, the dynamic deformation modulus Evd is tested for the section where f1 / f2>0.5. When it is detected that the dynamic deformation modulus Evd does not meet the design standard, the value of (f1-f2')-f2 is defined as a temporary judgment standard value; the temporary judgment standard value will gradually approach a fixed value as the number of tests increases, and finally the fixed value to which the temporary judgment standard value gradually approaches is used as the judgment standard value S; In the compaction quality detection of the detection section in this embodiment, the reason why the compaction quality judgment formula of the detection section is different from that of the first embodiment is that: because the traction value f1 detected by the first detection vehicle at a certain point of the detection section includes the traction value f2 detected by the second detection vehicle at a certain point of the detection section, it is necessary to subtract the influence of the traction value f2 from the traction value f1 before the traction value f1 and the traction value f2 can be compared on the same basis, so there is a (f1-f2') term to eliminate the traction value f2 included in the traction value f1; when (f1-f2')-f2 is greater than or equal to the judgment standard value S, it is determined that the compaction quality defect of the corresponding point of the detection section does not meet the standard exists; It is additionally noted that, in this embodiment, since there are two inspection vehicles, in order to ensure the accuracy of the test results, it is necessary to ensure that the initial traction of the two inspection vehicles (generated by the friction of the bearings rotatably connected to the test wheel 2.1 and the test wheel shaft 2.2) is equal. For example, when performing a calibration test on a cement road surface, the test data should be f1=2*f2; if f1>2*f2 during the calibration test, it means that the initial traction of the first inspection vehicle is greater than the initial traction of the second inspection vehicle. Therefore, before the actual test, it is necessary to reduce the initial traction by adjusting the initial negative clearance state of the bearings rotatably connected to the test wheel 2.1 and the test wheel shaft 2.2 in the first inspection vehicle, or increase the initial traction by adjusting the initial negative clearance state of the bearings rotatably connected to the test wheel 2.1 and the test wheel shaft 2.2 in the second inspection vehicle, so that the initial traction of the two inspection vehicles remains consistent, but this adjustment method is relatively cumbersome; Preferably, another method for adjusting the initial traction of the two test vehicles is: magnetorheological fluid dampers 10 are symmetrically arranged on both sides of the test wheels 2.1 in the two test vehicles, and the initial traction of the two test vehicles is kept consistent by adjusting the resistance of the magnetorheological fluid dampers 10 in the two test vehicles. The symmetrical arrangement of the magnetorheological fluid dampers 10 prevents the test vehicles from deviating due to the different resistance on both sides of the test wheels 2.1 during driving. In addition, the magnetorheological fluid dampers 10 are installed on the test vehicles, which can not only ensure that the initial traction of the two test vehicles is consistent, but also can be designed according to the dynamic deformation modulus Evd of the road surface to be tested in the on-site work (for example, the dynamic deformation modulus E When the vd design index is high, the initial traction of the inspection vehicle will be smaller; when the dynamic deformation modulus Evd design index is low, the initial traction of the inspection vehicle will be larger), the initial traction of the two inspection vehicles is adjusted to make the resistance strain gauge 4.4 in the optimal linear working range, thereby improving the detection accuracy of the traction; when the magnetorheological fluid damper 10 is installed on the inspection vehicle, the magnetorheological fluid damper 10 is electrically connected to the data collector 7, and the data collector 7 adjusts the resistance of the magnetorheological fluid damper 10; this method of adjusting the initial traction of the two inspection vehicles is more convenient and quick, and greatly shortens the preparation time before the inspection of the highway subgrade compaction quality inspection vehicle.

[0026] Parts of the present invention not described in detail are prior art.

Claims

1. A highway subgrade compaction quality inspection vehicle, characterized by: The invention comprises a vehicle body (1), a test wheel assembly (2), a traction head (4), and a loading platform (6); the test wheel assembly (2) is rotatably arranged at the lower part of the vehicle body (1); the traction head (4) is fixedly arranged at one end or both ends of the vehicle body (1); the loading platform (6) is fixedly arranged at the upper part of the vehicle body (1); and a loading plate (8) is arranged at the upper part of the loading platform (6); when the compaction quality of the highway subgrade is tested, the testing vehicle is towed by the traction vehicle (9) to pass over the subgrade to be tested twice, and the compaction quality of the highway subgrade is judged by comparing the difference between the two traction forces with a standard value.

2. The highway subgrade compaction quality inspection vehicle according to claim 1 is characterized by: The test wheel assembly (2) comprises a test wheel (2.1) and a test wheel rotating shaft (2.2); the test wheel (2.1) and the test wheel rotating shaft (2.2) are rotatably connected via a bearing; and both ends of the test wheel rotating shaft (2.2) are fixedly arranged on the lower part of the vehicle body (1) via a test wheel bracket (3).

3. The highway subgrade compaction quality inspection vehicle according to claim 1 is characterized by: The traction head (4) is arranged at the same height as the test wheel shaft (2.2).

4. The highway subgrade compaction quality inspection vehicle according to any one of claims 1 to 3, characterized in that: A resistance strain gauge (4.4) is fixedly attached to the traction head (4); a data collector (7) is provided on the vehicle body (1); the resistance strain gauge (4.4) is electrically connected to the data collector (7), and the data collector (7) is communicatively connected to a data processing device.

5. The highway subgrade compaction quality inspection vehicle according to claim 4 is characterized by: A separation groove (2.1.1) is provided in the middle of the outer circumferential surface of the test wheel (2.1), and the separation groove (2.1.1) separates the outer circumferential surface of the test wheel (2.1) into symmetrical test wheel flanges (2.1.2).

6. The highway subgrade compaction quality inspection vehicle according to claim 5 is characterized by: The data collector (7) is provided with a camera.

7. A highway subgrade compaction quality inspection vehicle according to claim 6, characterized in that: The two inspection vehicles are connected in series by a connecting shaft (5) through a traction head (4) provided at the end, forming a two-stage series inspection vehicle; when the roadbed compaction quality inspection is performed, the two inspection vehicles connected in series are towed by a traction vehicle (9) and travel over the roadbed to be inspected at one time, and the roadbed compaction quality is judged by comparing the difference in traction between the two inspection vehicles with a standard value.

8. A highway subgrade compaction quality inspection vehicle according to claim 7, characterized in that: A magnetorheological fluid damper (10) is arranged between the test wheel (2.1) and the test wheel rotating shaft (2.2); two magnetorheological fluid dampers (10) are provided and are symmetrically arranged on both sides of the test wheel (2.1); and the magnetorheological fluid dampers (10) are electrically connected to the data collector (7).

9. A detection method based on the highway subgrade compaction quality detection vehicle according to claim 6, characterized in that: The following steps are involved: S9.

1. Preparation before testing: a loading plate (8) of standard weight is set on the loading platform (6) of the testing vehicle; marking lines are made at the starting position and the ending position of the road surface to be tested; the testing vehicle is connected to the rear end of the tractor (9) through a traction head (4); the tractor (9) is parked 10-20 meters in front of the starting position of the road section to be tested; the standard weight of the loading plate (8) is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width (m) of the test wheel (2.1); D is the maximum diameter of the test wheel (2.1); K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the test vehicle itself; this formula is obtained by converting the linear load q = G / L formula of the compacting wheel of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd = K*q / D; where K is a dimensionless empirical coefficient, and its specific value in actual testing needs to be determined based on experiments; S9.2, first detection: start the tractor (9), and the tractor (9) travels along the road surface to be detected at a set speed of 2-4 km / h; when the camera in the data acquisition device (7) captures the marking line of the starting position of the detection section, the data acquisition device (7) collects the output data of the resistance strain gauge (4.4) at a set frequency and transmits it to the data processing device for storage; when the camera in the data acquisition device (7) captures the marking line of the end position of the detection section, the data acquisition ends; S9.3, second test: the tractor (9) is parked again 10-20 meters before the starting position of the road section to be tested; the tractor (9) is started, and the tractor (9) travels along the first driving trajectory of the test section at a set speed of 2-4 km / h; when the camera in the data acquisition device (7) captures the marking line at the starting position of the test section, the data acquisition device (7) collects data from the resistance strain gauge (4.4) at a set frequency, and transmits the data to the data processing device for storage; when the camera in the data acquisition device (7) captures the marking line at the end position of the test section, the data acquisition ends; S9.

4. Data processing: S9.4.

1. Process the resistance strain gauge (4.4) data collected during the two tests and convert them into the traction force of the tractor (9) on the test vehicle during the two tests; fit the traction force data of the two tests into two traction force change curves FL and perform filtering and smoothing processing; merge the two traction force change curves FL after smoothing processing into the same traction force change curve FL coordinate system; S9.4.

2. Determine the compaction quality of the tested road section according to formula (2): F1-F2≥S …… (2) In formula (2), F1 is the traction value of the first test at a certain point on the test section; F2 is the traction value of the second test at a certain point on the test section; S is the set judgment standard value, which is determined by actual test data; When F1-F2 is greater than or equal to the judgment standard value S, it is determined that the compaction quality of the corresponding point of the detected section does not meet the standard.

10. A detection method based on the highway subgrade compaction quality detection vehicle according to claim 8, characterized in that: The following steps are involved: S10.

1. Preparation before testing: Calibrate the initial traction of the secondary tandem testing vehicle to make the initial traction of the two testing vehicles equal; Loading plates (8) of the same standard weight are respectively arranged on the loading platform (6) of the secondary series test vehicle; marking lines are made at the starting position and the ending position of the road surface to be tested; the secondary series test vehicle is connected to the rear end of the tractor (9) through a traction head (4); the tractor (9) is parked 10-20 meters in front of the starting position of the road section to be tested; wherein the standard weight of the loading plate (8) is determined by formula (1): G = Evd * l * D / Kg …… (1) In formula (1), G is the standard weight (kg) of the applied loading plate (8); Evd is the dynamic deformation modulus of the highway subgrade design index; l is the effective width (m) of the test wheel (2.1); D is the maximum diameter of the test wheel (2.1); K is the proportional coefficient of the conversion between the linear load q and the dynamic deformation modulus Evd; g is the weight of the test vehicle itself; this formula is obtained by converting the linear load q = G / L formula of the compacting wheel of the roller and the conversion relationship between the linear load q and the dynamic deformation modulus Evd Evd = K*q / D; where K is a dimensionless empirical coefficient, and its specific value in actual testing needs to be determined based on experiments; S10.2, detection: start the tractor (9), and the tractor (9) drives along the road surface to be detected at a set speed of 2-4 km / h; when the camera in the data acquisition device (7) on the detection vehicle adjacent to the tractor (9) captures the starting position mark line of the detection section, the data acquisition devices (7) on the two detection vehicles synchronously collect the output data of the resistance strain gauge (4.4) on the traction head (4) at the front end of the corresponding detection vehicle at the set frequency, and transmit it to the data processing device for storage; when the camera in the data acquisition device (7) on the detection vehicle far away from the tractor (9) captures the end position mark line of the detection section, the data acquisition devices (7) on the two detection vehicles end data collection; S10.

3. Data processing: S10.3.

1. Process the data of the resistance strain gauges (4.4) collected by the two data collectors (7) and convert them into the traction of the two test vehicles; fit the traction data of the two test vehicles into two traction change curves fL respectively, and perform filtering and smoothing processing; merge the two traction change curves fL after smoothing processing into the same traction change curve fL coordinate system; shift the second traction change curve f2-L to the left by △L, so that the two traction change curves fL are synchronized in the same traction change curve coordinate system, that is, they are guaranteed to be the same in the position of the test section; wherein △L is the distance between the test wheels (2.1) of the two test vehicles; S10.3.

2. Determine the compaction quality of the tested road section according to formula (3): (f1-f2')-f2≥S......(3) In formula (3), f1 is the traction value detected by the first detection vehicle at a certain point on the detection section; f2 is the traction value detected by the second detection vehicle at a certain point on the detection section; f2' is the average traction force value of the second test vehicle in the entire test section; S is the set judgment standard value, which is determined by actual test data; When (f1-f2')-f2 is greater than or equal to the judgment standard value S, it is determined that the corresponding point of the detected section has a compaction quality defect that does not meet the standard.

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