Cushion-free novel airport runway test device and test method thereof

Abstract

The invention discloses a cushion-free novel airport runway test device which comprises a test tank, the test tank is filled with a base soil body, a cushion-free runway is arranged on the base soil body, two ends of the cushion-free runway are in smooth butt joint with a test runway, a bearing guide rail is arranged above the test runway and the cushion-free runway, and the bearing guide rail is arranged above the test runway and the cushion-free runway. A driving unit for controlling the bearing guide rail to move along the bearing guide rail is arranged on the bearing guide rail, a hydraulic lifting platform is arranged at the bottom of the driving unit, an elastic loading mechanism is arranged at the bottom of the hydraulic lifting platform, and a loading wheel is arranged at the bottom of the elastic loading mechanism; according to the scheme, aiming at the high underground water level working condition of a clay area, the influence of high underground water level moisture migration and aircraft operation load on a pavement structure is integrated, a load simulation test is performed on a cushion-free field pavement, and an environment simulation test is performed on a base layer soil body; the structural long-term working performance and the performance evolution mechanism of the cushion-free track under the combined action of base soil moisture migration and enrichment and the aircraft load dynamic effect are obtained.

Description

Technical Field

[0001] The invention relates to the technical field of airport runway testing, and in particular to a novel airport runway testing device without a cushion layer and a testing method thereof. Background Art

[0002] As an important facility of the comprehensive transportation system, the airport plays an irreplaceable role in the national economic construction and national defense construction, and is an important part of urban and air transportation. In recent years, with the continuous development of the national economy, the number and scale of airports have continued to expand. Ensuring the safety of airport pavement structures has always been a matter of great importance to aviation management departments. Cement concrete pavements have always been the main structural form of my country's airports (basically accounting for more than 90% of the total number of airports in my country) due to their advantages such as high strength and good durability. However, cement concrete is a brittle material, and its tensile strength is far lower than its compressive strength. If the airport roadbed is not dense, loose, or hollow, the aircraft load will easily cause cracks and breakages in the concrete slabs, and the concrete slabs will develop rapidly after damage occurs, ultimately affecting the performance of the airport pavement structure.

[0003] In engineering practice, a large part of common concrete pavement diseases are caused by voids or uneven deformation in the base. There are many factors that cause uneven deformation, but most of the diseases are caused by the action of water; because the strength and stability of the soil base are closely related to its humidity conditions to a large extent, the strength of the soil base in a dry state is higher, and vice versa.

[0004] In areas with high groundwater levels, a cushion layer is usually set on the soil foundation to protect the pavement structure layer. Its main functions are to isolate water, drain water, and prevent freezing to improve the working conditions of the base and soil foundation, and high water stability requirements are placed on the cushion layer. When there is no cushion layer on the base, the high water level of the stratum will inevitably affect the working performance and long-term durability of the upper pavement structure. The deterioration of the engineering performance of the base soil foundation caused by the high groundwater level and its adverse effects on the upper pavement structure layer cannot be ignored. The weakening of the stiffness and dynamic performance of the lower soil foundation is bound to reduce the operating level and durability of the upper pavement structure. However, current domestic and foreign research has mostly focused on the study of the mechanism affecting the migration of water in the roadbed, and few consider the impact of soil foundation immersion on the upper airport pavement structure layer under the condition of no cushion layer.

[0005] At the same time, considering the impact of airport operating conditions, the performance evolution mechanism of airport pavement structure under aircraft load cannot be ignored. At present, a large number of studies have been carried out on the performance of airport pavement structure under aircraft load at home and abroad. The general aircraft load analysis simplifies the aircraft load into a static load, or multiplies the aircraft static load by an empirical amplification factor to consider the impact of aircraft dynamics, and rarely considers the movement characteristics and vibration characteristics of the load itself. In addition, most studies are limited to simulating the effect of a single load, while the airport runway is subjected to reciprocating motion in the form of aircraft taxiing, takeoff, landing, etc. If you want to fully analyze the changes in the performance of the pavement structure, you must also consider the cyclic effect of the load. At the same time, few existing studies involve the problem of plastic damage of the airport rigid pavement during long-term use. The airport pavement is an engineering structure under cyclic load, and plastic damage will continue to accumulate during use. The current airport pavement analysis mainly studies the mechanical response of the pavement under the influence of load, and has not conducted an in-depth analysis of the structural performance attenuation of the pavement under long-term load, which directly leads to the low practicality of the analysis results and little guiding significance for the pavement structure design.

[0006] Therefore, for the high groundwater level conditions in clay areas, it is necessary to study the evolution mechanism and long-term performance of airport pavement structures under the combined effects of soil moisture migration and enrichment and aircraft load dynamic effects. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the present invention provides a test device and a test method for a new type of airport runway without a cushion, and studies and analyzes the performance of the new type of airport runway without a cushion under aircraft load and high groundwater level conditions, so as to provide technical support and practical reference for the structural design, construction and maintenance of the airport runway.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is:

[0009] In a first aspect, a new type of airport runway test device without cushion is provided, which includes a test trough box, the test trough box is filled with a base soil, a runway without cushion is arranged on the base soil, a test runway is smoothly connected at both ends of the runway without cushion, a bearing guide rail is arranged above the test runway and the runway without cushion, a driving unit for controlling its movement along the bearing guide rail is arranged on the bearing guide rail, a hydraulic lifting platform is arranged at the bottom of the driving unit, an elastic loading mechanism is arranged at the bottom of the hydraulic lifting platform, and a load wheel is arranged at the bottom of the elastic loading mechanism; the vertical A number of water level sensors and soil parameter sensors with detection ends extending deep into the base soil are arranged in the vertical direction, the outer side of the test tank box is wrapped with a thermal insulation layer, a number of water adding nozzles, a number of salt spray nozzles and a number of fluorescent lamps are arranged on both sides of the upper port of the test tank box, the number of water adding nozzles are connected to the first flexible pipe, a water filling tray is arranged at the bottom of the test tank box, a second flexible pipe and a drain pipe are arranged on the water filling tray, the first flexible pipe and the second flexible pipe are connected to the water adding mechanism through a three-way valve; a first temperature control coil for cooling or heating is embedded in the surrounding wall of the test tank box located at the upper port.

[0010] Furthermore, the elastic loading mechanism includes a base plate fixed at the bottom of the hydraulic lifting platform, the base plate is fixedly connected to the supporting plate located therebelow through a number of columns, a loading plate is arranged below the supporting plate, a load wheel is arranged at the bottom of the loading plate, a number of guide columns are arranged on the loading plate, a number of linear bearings are embedded on the supporting plate for the guide columns to pass through, a limiting head is arranged at the upper end of the guide column, and a number of loading springs are arranged between the supporting plate and the loading plate.

[0011] Furthermore, a pressure sensor for measuring the loading elastic force is arranged between the loading spring and the bearing plate.

[0012] Furthermore, the water adding mechanism includes a Martens flask, which is arranged on a linear module that can control its lifting and lowering, an air guide tube is arranged in the Martens flask, and a water level sensor is arranged on the side wall of the Martens flask flush with the lower end of the air guide tube, and a water inlet and a water outlet are respectively arranged at the upper and lower ends of the Martens flask, the water outlet is connected to the three-way valve through a flexible tube, the water inlet is connected to the water tank through a flexible tube and a water pump, and a second temperature control coil that can adjust the water temperature is arranged in the water tank.

[0013] Furthermore, the cushion-free tunnel is located in the middle of the surface of the base soil, and the width of the cushion-free tunnel is smaller than the width of the base soil, the heights of several water nozzles and several salt mist nozzles are higher than the height of the cushion-free tunnel, and the nozzles of several water nozzles and several salt mist nozzles are all inclined toward the surface of the cushion-free tunnel.

[0014] Furthermore, the cushion-free track includes a capillary barrier layer arranged on the base soil, a cement concrete surface layer is arranged on the capillary barrier layer, fiber material is added to the cement concrete surface layer, the fiber material is steel fiber, glass fiber, carbon fiber and / or polypropylene fiber, and a plurality of strain gauges are arranged in the capillary barrier layer and the cement concrete surface layer.

[0015] In a second aspect, a test method for a new type of airport runway test device without cushion is provided, which includes a load test method for the runway without cushion and a simulation test method for the base soil body that are carried out simultaneously and continuously, and a structure detection method for the runway without cushion that is carried out regularly;

[0016] The load test methods for uncushioned tracks include:

[0017] S1: When a taxiing load test is required for a runway without cushion, step S2 is executed; when a takeoff load test is required for a runway without cushion, step S4 is executed; when a landing load test is required for a runway without cushion, step S5 is executed;

[0018] S2: Control the load wheel to descend through the hydraulic lifting platform until the load wheel contacts the test track, and apply a constant load to the load wheel through the cooperation of the hydraulic lifting platform and the elastic loading mechanism;

[0019] S3: The drive unit drives the load wheel to slide on the test track and the track without cushion layer;

[0020] S4: executing steps S2-S3, when the load wheel slides on the track without cushion layer, the load on the load wheel is gradually reduced by the cooperation of the hydraulic lifting platform and the elastic loading mechanism;

[0021] S5: While the driving unit drives the load wheel to move in mid-air, the hydraulic lifting platform controls the load wheel to descend until the load wheel contacts the track without cushion layer and slides on it;

[0022] S6: While the load wheel is sliding on the track without cushion layer, the load wheel is gradually loaded through the cooperation of the hydraulic lifting platform and the elastic loading mechanism;

[0023] The simulation test methods for base soil include:

[0024] A1: Collect the four-season environmental parameters of the base soil on site, including the compaction degree of the base soil, the water temperature and water level in the base soil, and the four-season weather of the environment;

[0025] A2: According to the environmental parameters of the four seasons, one or more states of evaporation, freeze-thaw, infiltration, constant freezing and salt spray are selected for single state simulation or multi-state cycle simulation;

[0026] A3: The soil parameter sensor is used to monitor the moisture content of the base soil at different depths in real time, and the moisture migration change mechanism of the base soil during the simulation process is obtained;

[0027] The structural inspection method of the non-cushioned track includes: performing crack inspection on the non-cushioned track by an ultrasonic crack detector, performing deformation inspection on the non-cushioned track by a plurality of strain gauges, and performing flatness inspection on the surface of the non-cushioned track by a flatness detector.

[0028] Furthermore, the simulation methods for the five simulation states of evaporation, infiltration, constant freezing, freeze-thaw and salt spray include:

[0029] A21: When evaporation state simulation is required, step A22 is executed; when infiltration state simulation is required, step A24 is executed; when constant freezing state simulation is required, step A26 is executed; when freeze-thaw state simulation is required, step A27 is executed;

[0030] A22: The surface temperature of the base soil is increased by the first temperature control coil, the water temperature in the water tank is increased by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is flush with the required water level in the base soil;

[0031] A23: connect the water outlet of the Martens flask to the second flexible pipe through the three-way valve, and supply water to the bottom of the base soil through the water tank, the Martens flask and the water filling tray in sequence;

[0032] A24: The surface temperature of the base soil is adjusted by the first temperature control coil, the water temperature in the water tank is adjusted by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is higher than the height of the base soil surface;

[0033] A25: Open the drainage pipe, connect the water outlet of the Martens flask with the first flexible pipe through the three-way valve, and continuously supply water to the surface of the base soil through the water tank, the Martens flask and several water adding nozzles in sequence;

[0034] A26: The water temperature in the water tank is lowered by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is flush with the required water level of the base soil;

[0035] A27: Connect the water outlet of the Martens flask to the second flexible pipe through the three-way valve, and supply water to the bottom of the base soil through the water tank, the Martens flask and the water filling tray in sequence until the water level in the base soil reaches a preset height, and then close the three-way valve; reduce the surface temperature of the base soil through the first temperature control coil;

[0036] A28: After executing steps A26-A27, the surface temperature of the base soil is increased by the first temperature control coil, and the water outlet of the Martens flask is connected to the second flexible pipe through the three-way valve;

[0037] In the process of executing steps A21-A28, when salt spray state simulation is required, salt spray is applied to the surface of the non-cushioned field track and the base soil through a plurality of salt spray nozzles.

[0038] Furthermore, the method for loading the load wheel is: controlling the extension of the hydraulic lifting platform and increasing the compression of several loading springs between the load-bearing plate and the loading plate; the method for reducing the load on the load wheel is: controlling the contraction of the hydraulic lifting platform and reducing the compression of several loading springs between the load-bearing plate and the loading plate.

[0039] The beneficial effects of the present invention are:

[0040] 1. This plan targets the high groundwater level conditions in clay regions, comprehensively considers the impact of high groundwater level water migration and aircraft operating loads on pavement structure, conducts load simulation tests on pavements without cushion layers, and conducts environmental simulation tests on base soils, in order to obtain the long-term structural performance and performance evolution mechanism of pavements without cushion layers under the combined effects of base soil water migration enrichment and aircraft load dynamic effects, and provide technical support and practical reference for the structural design, construction and maintenance of similar airport pavements under special conditions.

[0041] 2. This scheme can simulate the taxiing, take-off and landing of the load wheels through the cooperation of the hydraulic lifting platform, elastic loading mechanism and drive unit, so that the dynamic load on the uncushioned runway is closer to the actual working conditions of the airport, thereby improving the accuracy of the structural performance attenuation analysis of the uncushioned runway under long-term dynamic loads.

[0042] 3. This scheme simulates one or more states of evaporation, freeze-thaw, infiltration, constant freezing and salt spray on the base soil according to the four-season environmental parameters collected on site, so as to correspond to different climates in the actual environment and make the simulation test of the base soil closer to the changeable real environment; among them, the evaporation state can simulate the process of water evaporation in the base soil in summer or when the temperature is high; the infiltration state can simulate the process of rainwater scouring the non-cushioned field road and infiltrating into the base soil in the rainy season; the constant freezing state can simulate the state of the base soil being cold and the water in it being frozen in winter or when the temperature is low; the freeze-thaw state can simulate the process of the base soil warming up and the water thawing when the temperature rises; the salt spray state can simulate the corrosion effect of the non-cushioned field road in the coastal area; at the same time, in the simulation test of the base soil, the water content of the base soil is monitored in real time to obtain the water migration mechanism of the base soil caused by the groundwater level, and on this basis, the influence mechanism of water enrichment on the mechanical properties of the shallow base soil is revealed, which provides a basis for the subsequent structural design and performance analysis of the non-cushioned field road.

[0043] 4. In this scheme, when the water level in the Malchnitz flask drops to the lower end of the air pipe, the water level sensor can send a signal and automatically replenish water to the Malchnitz flask through the water tank, so that the water level in the Malchnitz flask is always higher than the lower end of the air pipe. The Malchnitz flask uses the principle of constant water head to provide a constant water level replenishment effect for the base soil to simulate the stable groundwater level in the base soil in the actual environment. At the same time, the height of the Malchnitz flask can be adjusted by the linear module to achieve the purpose of adjusting the water level. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the structure of a new type of airport runway test device without a cushion.

[0045] Figure 2 It is a structural schematic diagram of the elastic loading mechanism.

[0046] Figure 3 It is a structural diagram of the water adding mechanism.

[0047] Among them, 1. test trough box, 2. base soil, 3. non-cushion field road, 4. load-bearing guide rail, 5. drive unit, 6. hydraulic lifting platform, 7. elastic loading mechanism, 8. load wheel, 9. water level sensor, 10. soil parameter sensor, 11. water adding nozzle, 12. salt spray nozzle, 13. fluorescent lamp, 14. first flexible pipe, 15. water filling tray, 16. second flexible pipe, 17. drainage pipe, 18. three-way valve, 1 9. water adding mechanism, 20. first temperature control coil, 21. base plate, 22. column, 23. bearing plate, 24. loading plate, 25. guide column, 26. linear bearing, 27. limit head, 28. loading spring, 29. pressure sensor, 30. Martens flask, 31. linear module, 32. air guide tube, 33. water pump, 34. water tank, 35. second temperature control coil, 36. capillary barrier layer, 37. cement concrete surface layer. DETAILED DESCRIPTION

[0048] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0049] Example 1

[0050] like Figures 1 to 3 As shown, the cushion-free new airport runway test device of this scheme includes a test tank box 1, which is filled with a base soil 2, and a plurality of water level sensors 9 and soil parameter sensors 10 with detection ends extending into the base soil 2 are arranged in the vertical direction of the side wall of the test tank box 1, which are used to detect the water level and water content in the base soil 2; the outer side of the test tank box 1 is wrapped with a thermal insulation layer, and a plurality of water adding nozzles 11, a plurality of salt spray nozzles 12 and a plurality of fluorescent lamps 13 are arranged on both sides of the upper port of the test tank box 1, which are used to simulate a rainfall environment, a coastal salt spray environment and a lighting environment respectively; A plurality of water adding nozzles 11 are connected to the first flexible pipe 14, a water filling tray 15 is arranged at the bottom of the test tank box 1, a second flexible pipe 16 and a drain pipe 17 are arranged on the water filling tray 15, the first flexible pipe 14 and the second flexible pipe 16 are connected to the water adding mechanism 19 through a three-way valve 18, so that the water adding mechanism 19 can supply water to the water adding nozzle 11 or the water filling tray 15 through the three-way valve 18, and a first temperature control coil 20 for cooling or heating is embedded in the peripheral wall of the test tank box 1 at the upper port, and the first temperature control coil 20 is used to simulate the temperature influence of the external environment climate on the surface of the base soil 2.

[0051] A non-cushion track 3 is arranged on the base soil 2, and a test track is smoothly connected to both ends of the non-cushion track 3. A load-bearing guide rail 4 is arranged above the test track and the non-cushion track 3, and a driving unit 5 that can control itself to move along the load-bearing guide rail 4 is arranged on the load-bearing guide rail 4. A hydraulic lifting platform 6 is arranged at the bottom of the driving unit 5, and an elastic loading mechanism 7 is arranged at the bottom of the hydraulic lifting platform 6. A load wheel 8 is arranged at the bottom of the elastic loading mechanism 7, and the load wheel 8 can perform a dynamic load simulation test on the non-cushion track 3.

[0052] This scheme targets the high groundwater level working condition in clay areas, comprehensively considers the influence of high groundwater level water migration and aircraft operation load on pavement structure, conducts load simulation test on pavement without cushion layer 3, and conducts environmental simulation test on base soil 2, so as to obtain the long-term structural working performance and performance evolution mechanism of pavement without cushion layer 3 under the combined action of water migration enrichment in base soil 2 and dynamic effect of aircraft load, and provides technical support and practical reference for the structural design, construction and maintenance of similar airport pavements under special working conditions.

[0053] During specific implementation, the cushion-free field road 3 is located in the middle of the base soil 2, and the width of the cushion-free field road 3 is smaller than the width of the base soil 2, so that part of the surface of the base soil 2 on both sides is exposed; the heights of several water-adding nozzles 11 and several salt mist nozzles 12 are higher than the height of the cushion-free field road 3, and the nozzles of several water-adding nozzles 11 and several salt mist nozzles 12 are inclined toward the surface of the cushion-free field road 3, so that the water-adding nozzles 11 and the salt mist nozzles 12 can spray water or salt mist on the surface of the cushion-free field road 3, and the ice water and rainwater first flush the cushion-free field road 3, and then penetrate into the base soil 2 through the surface of the base soil 2 on both sides of the cushion-free field road 3, so that the simulation of the rainfall environment is closer to reality.

[0054] The non-cushioned pavement 3 includes a capillary barrier layer 36 arranged on the base soil 2, and a cement concrete surface layer 37 is arranged on the capillary barrier layer 36. Fiber material is added to the cement concrete surface layer 37, and the fiber material is steel fiber, glass fiber, carbon fiber and / or polypropylene fiber. A number of strain gauges are arranged in the capillary barrier layer 36 and the cement concrete surface layer 37. By arranging the capillary barrier layer 36 to replace the cushion layer in the traditional airport pavement, based on the capillary barrier principle and the difference in permeability coefficient, the infiltration of groundwater is effectively restricted, thereby achieving an anti-seepage effect, playing a role in protecting the cement concrete surface layer 37, and providing a new idea for the structural design of airport pavement under high groundwater level conditions in clay areas; by adding fiber material to the cement concrete surface layer 37, the fiber material can effectively control cracks in the concrete, while improving the compressive strength and hardness of the concrete, thereby making the cement concrete surface layer 37 have the technical effect of toughening and crack resistance.

[0055] Example 2

[0056] like Figure 2 As shown, based on Example 1, this embodiment provides a specific scheme of the elastic loading mechanism 7. The elastic loading mechanism 7 includes a base plate 21 fixed to the bottom of the hydraulic lifting platform 6. The base plate 21 is fixedly connected to a bearing plate 23 located therebelow through a plurality of columns 22. A loading plate 24 is arranged below the bearing plate 23. The load wheel 8 is arranged at the bottom of the loading plate 24. A plurality of guide columns 25 are arranged on the loading plate 24. A plurality of linear bearings 26 for facilitating the passage of the guide columns 25 are embedded on the bearing plate 23. A limit head 27 is arranged at the upper end of the guide column 25. A plurality of loading springs 28 are arranged between the bearing plate 23 and the loading plate 24. A pressure sensor 29 for measuring the loading elastic force is arranged between the loading spring 28 and the bearing plate 23.

[0057] In this solution, the driving unit 5 can drive the load wheel 8 to slide on the non-cushioned runway 3. The extension or contraction of the hydraulic lifting platform 6 can increase or decrease the compression amount of the plurality of loading springs 28 between the bearing plate 23 and the loading plate 24, thereby changing the load of the load wheel 8 on the non-cushioned runway 3. In conjunction with the driving unit 5, the load can be added or reduced during the sliding process of the load wheel 8, thereby simulating the sliding, take-off (load reduction) and landing (load) of the load wheel 8, so that the dynamic load on the non-cushioned runway 3 is closer to the actual working condition of the airport, thereby improving the accuracy of the structural performance attenuation analysis of the non-cushioned runway 3 under long-term dynamic loads.

[0058] Example 3

[0059] like Figure 3 As shown, on the basis of Example 1, this embodiment provides a specific scheme of the water adding mechanism 19, the water adding mechanism 19 includes a Martens flask 30, the Martens flask 30 is arranged on a linear module 31 which can control its lifting and lowering, an air guide tube 32 is arranged in the Martens flask 30, and a water level sensor 9 is arranged on the side wall of the Martens flask 30 which is flush with the lower end of the air guide tube 32, the upper and lower ends of the Martens flask 30 are respectively provided with a water inlet and a water outlet, the water outlet is connected to the three-way valve 18 through a flexible tube, the water inlet is connected to the water tank 34 through a flexible tube and a water pump 33, and a second temperature control coil 35 which can adjust the water temperature is arranged in the water tank 34.

[0060] When the water level in the Malchnitz flask 30 drops to the lower end of the air pipe 32, the water level sensor 9 can send a signal and automatically replenish water to the Malchnitz flask 30 through the water tank 34, so that the water level in the Malchnitz flask 30 is always higher than the lower end of the air pipe 32. The Malchnitz flask 30 uses the principle of constant water head to provide a constant water level replenishment effect for the base soil 2 to simulate the stable groundwater level in the base soil 2 in the actual environment. At the same time, the height of the Malchnitz flask 30 can be adjusted by the linear module 31 to achieve the purpose of adjusting the water level.

[0061] In combination with the above-mentioned embodiments 1-3, the present scheme also provides a test method for a new type of airport runway test device without a cushion, which includes a load test method for the runway without a cushion 3, a simulation test method for the base soil 2, and a structural detection method for the runway without a cushion 3; wherein, the load test of the runway without a cushion 3 and the simulation test of the base soil 2 are carried out simultaneously and continuously, so as to obtain the long-term structural working performance and performance evolution mechanism of the runway without a cushion 3 under the combined action of moisture migration and enrichment in the base soil 2 and the dynamic effect of aircraft loads; and the structural detection of the runway without a cushion 3 can be carried out regularly.

[0062] Specifically, the load test method of the non-cushion track 3 includes:

[0063] S1: When it is necessary to perform a taxiing load test on the non-cushioned runway 3, step S2 is executed; when it is necessary to perform a take-off load test on the non-cushioned runway 3, step S4 is executed; when it is necessary to perform a landing load test on the non-cushioned runway 3, step S5 is executed;

[0064] S2: Control the load wheel 8 to descend by the hydraulic lifting platform 6 until the load wheel 8 contacts the test track, and apply a constant load to the load wheel 8 by the cooperation of the hydraulic lifting platform 6 and the elastic loading mechanism 7;

[0065] S3: driving the load wheel 8 to slide on the test track and the track without cushion 3 through the drive unit 5;

[0066] S4: Execute steps S2-S3, and when the load wheel 8 slides on the track 3 without cushion layer, the load on the load wheel 8 is gradually reduced by the cooperation of the hydraulic lifting platform 6 and the elastic loading mechanism 7;

[0067] S5: while the driving unit 5 drives the load wheel 8 to move in midair, the hydraulic lifting platform 6 controls the load wheel 8 to descend until the load wheel 8 contacts the non-cushioned track 3 and slides on it;

[0068] S6: While the load wheel 8 is sliding on the non-cushioned track 3 , the load wheel 8 is gradually loaded through the cooperation of the hydraulic lifting platform 6 and the elastic loading mechanism 7 .

[0069] During the above test process, the method for loading the load wheel 8 is: controlling the extension of the hydraulic lifting platform 6 and increasing the compression of several loading springs 28 between the load-bearing plate 23 and the loading plate 24; the method for reducing the load on the load wheel 8 is: controlling the contraction of the hydraulic lifting platform 6 and reducing the compression of several loading springs 28 between the load-bearing plate 23 and the loading plate 24.

[0070] The simulation test method of the base soil 2 of this scheme includes:

[0071] A1: Collect the four-season environmental parameters of the base soil 2 on site, including the compaction degree of the base soil 2, the water temperature and water level in the base soil 2, and the four-season weather of the environment; and make the compaction degree of the base soil 2 in the test tank box 1 consistent with the compaction degree of the base soil 2 on site;

[0072] A2: According to the environmental parameters of the four seasons, one or more states of evaporation, freeze-thaw, infiltration, constant freezing and salt spray are selected for single state simulation or multi-state cycle simulation;

[0073] A3: The soil parameter sensor 10 is used to monitor the moisture content of the base soil 2 at different depths in real time, and the moisture migration change mechanism of the base soil 2 during the simulation process is obtained.

[0074] Among them, the simulation methods for the five simulation states of evaporation, infiltration, constant freezing, freeze-thaw and salt spray include:

[0075] A21: When evaporation state simulation is required, step A22 is executed; when infiltration state simulation is required, step A24 is executed; when constant freezing state simulation is required, step A26 is executed; when freeze-thaw state simulation is required, step A27 is executed;

[0076] A22: The surface temperature of the base soil 2 is increased by the first temperature control coil 20, the water temperature in the water tank 34 is increased by the second temperature control coil 35, and the height of the Martens flask 30 is adjusted by the linear module 31 until the lower end of the air guide tube 32 is flush with the required water level in the base soil 2;

[0077] A23: The water outlet of the Martens flask 30 is connected to the second flexible tube 16 through the three-way valve 18, and water is supplied to the bottom of the base soil 2 through the water tank 34, the Martens flask 30 and the water injection tray 15 in sequence;

[0078] A24: The surface temperature of the base soil 2 is adjusted by the first temperature control coil 20, the water temperature in the water tank 34 is adjusted by the second temperature control coil 35, and the height of the Malchnitz flask 30 is adjusted by the linear module 31 until the lower end of the air guide tube 32 is higher than the surface of the base soil 2;

[0079] A25: Open the drain pipe 17, connect the water outlet of the Malchnitz flask 30 with the first flexible pipe 14 through the three-way valve 18, and continuously supply water to the surface of the base soil 2 through the water tank 34, the Malchnitz flask 30 and the plurality of water supply nozzles 11 in sequence;

[0080] A26: The water temperature in the water tank 34 is lowered by the second temperature control coil 35, and the height of the Malchnitz flask 30 is adjusted by the linear module 31 until the lower end of the air guide tube 32 is flush with the required water level of the base soil 2;

[0081] A27: Connect the water outlet of the Martens flask 30 to the second flexible tube 16 through the three-way valve 18, and supply water to the bottom of the base soil 2 through the water tank 34, the Martens flask 30 and the water filling tray 15 in sequence until the water level in the base soil 2 reaches a preset height, and then close the three-way valve 18; reduce the surface temperature of the base soil 2 through the first temperature control coil 20;

[0082] A28: After executing steps A26-A27, the surface temperature of the base soil 2 is increased by the first temperature control coil 20, and the water outlet of the Martens flask 30 is connected to the second flexible tube 16 through the three-way valve 18;

[0083] In the process of executing steps A21 to A28, when salt spray state simulation is required, salt spray is applied to the surface of the non-cushioned field track 3 and the base soil 2 through a plurality of salt spray nozzles 12.

[0084] This scheme simulates one or more states of evaporation, freeze-thaw, infiltration, constant freezing, and salt spray on the base soil 2 according to the four-season environmental parameters collected on-site, so as to correspond to different climates in the actual environment and make the simulation test of the base soil 2 closer to the changeable real environment; among them, the evaporation state can simulate the process of water evaporation in the base soil 2 in summer or when the temperature is high; the infiltration state can simulate the process of rainwater scouring the non-cushioned field road 3 and infiltrating into the base soil 2 in the rainy season; the constant freezing state can simulate the process of the base soil 2 being affected by cold in winter or when the temperature is low. And the water inside it is in a frozen state; the freeze-thaw state can simulate the process of the base soil 2 warming up and the water thawing when the temperature rises; the salt spray state can simulate the corrosion effect of the non-cushioned field road 3 in the coastal area; at the same time, in the simulation test process of the base soil 2, through the real-time monitoring of the water content of the base soil 2, the water migration mechanism of the base soil 2 caused by the groundwater level is obtained, and on this basis, the influence mechanism of water enrichment on the mechanical properties of the shallow base soil 2 is revealed, which provides a basis for the subsequent structural design and performance analysis of the non-cushioned field road 3.

[0085] The structural inspection method of the cushion-less track 3 in this scheme includes: performing crack inspection on the cushion-less track 3 by an ultrasonic crack detector, performing deformation inspection on the cushion-less track 3 by a plurality of strain gauges, and performing flatness inspection on the surface of the cushion-less track 3 by a flatness detector; thereby realizing the inspection and evaluation of the structural performance of the cushion-less track 3.

[0086] In summary, this scheme targets the high groundwater level conditions in clay areas, comprehensively considers the influence of high groundwater level water migration and aircraft operation load on the pavement structure, conducts load simulation tests on the pavement without cushion layer 3, and conducts environmental simulation tests on the base soil 2, in order to obtain the long-term structural working performance and performance evolution mechanism of the pavement without cushion layer 3 under the combined action of water migration enrichment in the base soil 2 and the dynamic effect of aircraft loads, and provides technical support and practical reference for the structural design, construction and maintenance of similar airport pavements under special conditions.

Claims

1. A new type of airport runway test device without cushion layer, characterized in that: The invention comprises a test slot box, wherein the test slot box is filled with a base soil, a non-cushion track is arranged on the base soil, test tracks are smoothly butted at both ends of the non-cushion track, a bearing guide rail is arranged above the test track and the non-cushion track, a driving unit for controlling the bearing guide rail to move along the bearing guide rail is arranged on the bearing guide rail, a hydraulic lifting platform is arranged at the bottom of the driving unit, an elastic loading mechanism is arranged at the bottom of the hydraulic lifting platform, and a load wheel is arranged at the bottom of the elastic loading mechanism; A number of water level sensors and soil parameter sensors with detection ends extending into the base soil are arranged in the vertical direction of the side wall of the test tank box, the outer side of the test tank box is wrapped with a thermal insulation layer, a number of water adding nozzles, a number of salt spray nozzles and a number of fluorescent lamps are arranged on both sides of the upper port of the test tank box, and the number of water adding nozzles are connected to the first flexible pipe, a water filling tray is arranged at the bottom of the test tank box, a second flexible pipe and a drain pipe are arranged on the water filling tray, and the first flexible pipe and the second flexible pipe are connected to the water adding mechanism through a three-way valve; a first temperature control coil for cooling or heating is embedded in the surrounding wall of the test tank box located at the upper port.

2. The new type of airport runway test device without cushion layer according to claim 1 is characterized in that: The elastic loading mechanism includes a base plate fixed to the bottom of the hydraulic lifting platform, the base plate is fixedly connected to the bearing plate located below it through a plurality of columns, a loading plate is arranged below the bearing plate, the load wheel is arranged at the bottom of the loading plate, a plurality of guide columns are arranged on the loading plate, a plurality of linear bearings are embedded on the bearing plate for the guide columns to pass through, a limiting head is arranged on the upper end of the guide column, and a plurality of loading springs are arranged between the bearing plate and the loading plate.

3. The new type of airport runway test device without cushion layer according to claim 2 is characterized in that: A pressure sensor for measuring the loading elastic force is arranged between the plurality of loading springs and the bearing plate.

4. The new type of airport runway test device without cushion layer according to claim 1 is characterized in that: The water adding mechanism comprises a Martens flask, which is arranged on a linear module capable of controlling its lifting and lowering, an air guide tube is arranged in the Martens flask, and a water level sensor is arranged on the side wall of the Martens flask flush with the lower end of the air guide tube, a water inlet and a water outlet are arranged at the upper and lower ends of the Martens flask respectively, the water outlet is connected to a three-way valve through a flexible tube, the water inlet is connected to a water tank through a flexible tube and a water pump, and a second temperature control coil capable of adjusting the water temperature is arranged in the water tank.

5. The new type of airport runway test device without cushion layer according to claim 1 is characterized in that: The cushion-free field channel is located in the middle of the surface of the base soil, and the width of the cushion-free field channel is smaller than the width of the base soil. The heights of several water-adding nozzles and several salt spray nozzles are higher than the height of the cushion-free field channel, and the nozzles of several water-adding nozzles and several salt spray nozzles are all inclined toward the surface of the cushion-free field channel.

6. The new type of airport runway test device without cushion layer according to claim 1 is characterized in that: The cushion-free track includes a capillary barrier layer arranged on a base soil body, a cement concrete surface layer is arranged on the capillary barrier layer, fiber material is added to the cement concrete surface layer, and the fiber material is steel fiber, glass fiber, carbon fiber and / or polypropylene fiber. A plurality of strain gauges are arranged in the capillary barrier layer and the cement concrete surface layer.

7. A test method using the new airport runway test device without cushion layer as claimed in any one of claims 1 to 6, characterized in that: It includes the load test method of the non-cushion track and the simulation test method of the base soil body carried out simultaneously and continuously, as well as the structure inspection method of the non-cushion track carried out regularly; The load test methods for uncushioned tracks include: S1: When a taxiing load test is required for a runway without cushion, step S2 is executed; when a takeoff load test is required for a runway without cushion, step S4 is executed; when a landing load test is required for a runway without cushion, step S5 is executed; S2: Control the load wheel to descend through the hydraulic lifting platform until the load wheel contacts the test track, and apply a constant load to the load wheel through the cooperation of the hydraulic lifting platform and the elastic loading mechanism; S3: The drive unit drives the load wheel to slide on the test track and the track without cushion layer; S4: executing steps S2-S3, when the load wheel slides on the track without cushion layer, the load on the load wheel is gradually reduced by the cooperation of the hydraulic lifting platform and the elastic loading mechanism; S5: While the driving unit drives the load wheel to move in mid-air, the hydraulic lifting platform controls the load wheel to descend until the load wheel contacts the track without cushion layer and slides on it; S6: While the load wheel is sliding on the track without cushion layer, the load wheel is gradually loaded through the cooperation of the hydraulic lifting platform and the elastic loading mechanism; The simulation test methods for base soil include: A1: Collect the four-season environmental parameters of the base soil on site, including the compaction degree of the base soil, the water temperature and water level in the base soil, and the four-season weather of the environment; A2: According to the environmental parameters of the four seasons, one or more states of evaporation, freeze-thaw, infiltration, constant freezing and salt spray are selected for single state simulation or multi-state cycle simulation; A3: The soil parameter sensor is used to monitor the moisture content of the base soil at different depths in real time, and the moisture migration change mechanism of the base soil during the simulation process is obtained; The structural inspection method of the non-cushioned track includes: performing crack inspection on the non-cushioned track by an ultrasonic crack detector, performing deformation inspection on the non-cushioned track by a plurality of strain gauges, and performing flatness inspection on the surface of the non-cushioned track by a flatness detector.

8. The test method of the new airport runway test device without cushion layer according to claim 7 is characterized in that: The simulation methods for the five simulation states of evaporation, infiltration, constant freezing, freeze-thaw and salt spray include: A21: When evaporation state simulation is required, step A22 is executed; when infiltration state simulation is required, step A24 is executed; when constant freezing state simulation is required, step A26 is executed; when freeze-thaw state simulation is required, step A27 is executed; A22: The surface temperature of the base soil is increased by the first temperature control coil, the water temperature in the water tank is increased by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is flush with the required water level in the base soil; A23: connect the water outlet of the Martens flask to the second flexible pipe through the three-way valve, and supply water to the bottom of the base soil through the water tank, the Martens flask and the water filling tray in sequence; A24: The surface temperature of the base soil is adjusted by the first temperature control coil, the water temperature in the water tank is adjusted by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is higher than the height of the base soil surface; A25: Open the drainage pipe, connect the water outlet of the Martens flask with the first flexible pipe through the three-way valve, and continuously supply water to the surface of the base soil through the water tank, the Martens flask and several water adding nozzles in sequence; A26: The water temperature in the water tank is lowered by the second temperature control coil, and the height of the Martens flask is adjusted by the linear module until the lower end of the air guide tube is flush with the required water level of the base soil; A27: Connect the water outlet of the Martens flask to the second flexible pipe through the three-way valve, and supply water to the bottom of the base soil through the water tank, the Martens flask and the water filling tray in sequence until the water level in the base soil reaches a preset height, and then close the three-way valve; reduce the surface temperature of the base soil through the first temperature control coil; A28: After executing steps A26-A27, the surface temperature of the base soil is increased by the first temperature control coil, and the water outlet of the Martens flask is connected to the second flexible pipe through the three-way valve; In the process of executing steps A21-A28, when salt spray state simulation is required, salt spray is applied to the surface of the non-cushioned field track and the base soil through a plurality of salt spray nozzles.

9. The test method of the new airport runway test device without cushion layer according to claim 7 is characterized in that: The method for loading the load wheel is: controlling the extension of the hydraulic lifting platform and increasing the compression of several loading springs between the load-bearing plate and the loading plate; the method for reducing the load on the load wheel is: controlling the contraction of the hydraulic lifting platform and reducing the compression of several loading springs between the load-bearing plate and the loading plate.

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