CN111289391A - Reciprocating movement loading test system and test method for testing deformation of subgrade and pavement - Google Patents

Abstract

The invention discloses a reciprocating loading test system and a test method for testing the deformation of subgrade and pavement. The test system includes a subgrade pavement system, a driving device, a mobile wheel load simulation device and a measuring system; A clamping slot is arranged in the radial direction of the disc; the mobile wheel load simulation device includes a loading wheel, the loading wheel is in contact with the road-subgrade structure model, a horizontally arranged top plate is installed above the loading wheel, and the middle part of the shaft of the loading wheel is fixedly connected with the top plate through the loading shaft, A carrying plate is installed on the top plate, and weights are placed on the carrying plate. The end of the top plate close to the driving device is provided with a rotating support. The driving device and the mobile wheel load simulating device of the present invention constitute a dynamic loading system, which simulates the real state of the vehicle to a higher degree and improves the accuracy of predicting the deformation of the roadbed and pavement under the action of the vehicle load.

Description

Reciprocating movement loading test system and test method for testing deformation of subgrade and pavement

technical field

The invention belongs to the technical field of traffic engineering, and relates to a reciprocating movement loading test system and a test method for testing the deformation of roadbed and pavement.

Background technique

With the rapid development of the national economy, highway freight and passenger traffic have increased significantly, and the phenomenon of large-scale vehicles and heavy loads has emerged one after another. Heavy-duty vehicles pose a great challenge to the bearing capacity of the roadbed and the shear strength of the pavement due to its heavy weight, high speed and large number. Under heavy traffic conditions, the uneven settlement of the roadbed is aggravated, and rutting and cracks occur in the wheel track belt of the road surface. At the same time, water also has great harm to the roadbed and pavement. Surface water scours the pavement, causing water damage, and water seeps into the subgrade, making the subgrade soil too wet and reducing the subgrade strength. The light groundwater can make the subgrade wet and soft, reducing the strength of the subgrade, while the heavier groundwater can cause frost heave, pulping or slope slump, and even the entire subgrade slides along the inclined base. Heavy loads and water are the main reasons for the deformation of the subgrade and pavement, which lead to the failure of the road to be used normally within the designed service life. Damaged roads are not only expensive to maintain and repair, but also inconvenient to existing road traffic.

At present, conventional triaxial tests and electro-hydraulic servo loading tests are mostly used to test the deformation of roadbed and pavement. In the process of realizing the present invention, the inventor found that there are at least the following shortcomings in the prior art:

1. The above two methods do not consider the influence of water on the performance of the subgrade and pavement. Different groundwater levels and different rainfall conditions will affect the overall stress and soil strength of the subgrade and pavement, thereby affecting the deformation of the subgrade and pavement.

2. In the conventional triaxial test, the pavement base must be made into a cylinder sample, the boundary conditions are limited, and the thickness cannot be restored according to the actual engineering situation.

3. The conventional triaxial test does not consider the loading effect of the reciprocating movement of the vehicle and the influence of the acceleration and deceleration process of the vehicle on the roadbed.

4. The electro-hydraulic servo loading test adopts microcomputer control, and uses regular simple harmonics to simulate the vibration waveform of traffic load, ignoring the situation that the road surface is damaged and the coupling effect between the vehicle and the road surface is ignored as the vehicle is repeatedly loaded.

5. The above two methods do not consider the influence of the acceleration of the object carried by the vehicle on the force of the vehicle.

Therefore, in order to meet the needs of studying the long-term performance of subgrade and pavement under the action of heavy traffic loads and water, it is necessary to propose a reciprocating loading test system for testing the deformation of subgrade and pavement.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a reciprocating loading test system for testing the deformation of subgrade and pavement. The driving device and the mobile wheel load simulation device constitute a dynamic loading system, and the overall deformation of the subgrade and pavement under different conditions is obtained through the simulation test. Comprehensive research The law of the deformation of the subgrade and pavement under the action of the reciprocating moving load can simulate the real state of the vehicle to a higher degree, improve the accuracy of predicting the deformation of the subgrade and pavement under the action of the vehicle load, and solve the problems existing in the prior art.

Another object of the present invention is to provide a reciprocating loading test method for testing the deformation of subgrade pavement.

The technical scheme adopted in the present invention is a reciprocating moving loading test system for testing the deformation of subgrade and pavement, including a subgrade pavement system, a driving device, a mobile wheel load simulation device and a measurement system;

The roadbed pavement system includes a transparent glass box, a pavement-subgrade structure model is laid in the transparent glass box, and a measurement system is installed in the pavement-subgrade structure model;

The driving device comprises a rotating disc, a clamping slot is arranged along the radial direction of the rotating disc, a plurality of hinge holes are arranged on the clamping slot, and the rotating disc is driven by a motor to rotate around the center of the circle;

The mobile wheel load simulation device includes a loading wheel, the loading wheel is in contact with the road surface-subgrade structure model, a horizontally arranged top plate is installed above the loading wheel, the two loading wheels are coaxially connected, the middle of the shaft is fixedly connected with the top plate through the loading shaft, and the top plate is A bearing plate is installed on the bearing plate, and weights are placed on the bearing plate. The end of the top plate close to the driving device is provided with a rotating support.

Further, a vertical screw is connected to the top plate, the weight is annular, and is sleeved on the outside of the screw. There is a gap between the annular weight and the screw, and the width of the gap ranges from 0.075m to 0.15m.

Further, each of the four corners of the top plate is nested with a spherical guide wheel, the spherical guide wheel rotates freely relative to the top plate, and the side wall of the spherical guide wheel perpendicular to the movement direction of the mobile wheel load simulation device is in contact with the inner wall of the transparent glass box.

Further, the test system also includes a groundwater level simulation device, including a water level pipe. The water level pipe is placed in the transparent glass box at one end away from the driving device. Wrapped with gauze, the nozzle is higher than the transparent glass box, and the nozzle is installed with a nozzle cover; the water tank is connected to the bottom of the transparent glass box through a connecting water pipe, and a water inlet valve is arranged on the connecting water pipe, and a scale table is arranged above the water level pipe. The top and bottom of the watch are provided with wire clips for fixing the wires. The lower end of the wire is connected with a water level probe, which extends into the water level pipe. The water level probe is connected to the water level meter receiver through the wire inside the wire.

Further, the scale is fixed and supported by an inverted "L"-shaped support rod, and the inverted "L"-shaped support rod is placed outside the transparent glass box.

Further, the test system also includes a ground rainfall simulation device, including a shower, a beam, a column, a water pipe, and a water pump; the column is arranged at both ends of the transparent glass box, and the shower is fixed on the beam and suspended on the upper part of the roadbed pavement system. It is fixedly erected on two columns, and two diagonal struts are welded between the beam and the column to form a stable triangular structure; the bottom end of the column is welded with a heavy-duty base, which is placed on both sides of the transparent glass box; the shower is connected to the water tank through a water pipe , There is a water pump on the water pipe to control the simulated rainfall.

Further, there is a water outlet hole at the bottom of the other end of the transparent glass box, and a water outlet valve is arranged on the pipe connecting the water outlet hole.

Further, the pavement-subgrade structure includes a ground base, a road base and a pavement layer, which are sequentially laid in the transparent glass box from bottom to top.

Further, the measurement system includes a settlement plate, a seam gauge, a rutting depth detection tool, and a tape measure for measuring the length of the crack, the settlement plate includes a base plate, a measuring rod is arranged on the base plate, and a casing is provided outside the measuring rod. The upper port is provided with a plug; the settlement plate is buried at a depth of 10cm-15cm and a depth of 35cm-50cm below the pavement layer, and one is buried every 0.5m-1m, evenly distributed, to measure the settlement value of the road subgrade and pavement; The width of the crack is measured at the pavement depth of 8cm-12cm; the rutting depth detection tool includes a detection crossbar and a ruler.

A reciprocating loading test method for testing the deformation of subgrade and pavement, which is specifically carried out according to the following steps:

S1, fix the water level pipe vertically inside the transparent glass box, fill the transparent glass box with soil for testing according to the actual conditions of the road layer, lay the ground base, road base and pavement layer, and install the measurement system;

S2, touch the water level probe just to the bottom of the water level pipe, mark the wire at the zero scale position of the scale, and slowly pull the upper end of the wire so that the scale at the wire mark corresponds to the simulated water level height, and fix the wire with a wire clip as water level measurement status;

S3, open the water inlet valve, slowly feed water through the water tank and the connecting water pipe, when the actual water level touches the water level probe, the water level meter receiver will beep, close the water inlet valve, stop water injection, and reach the simulated water level required for the test;

S4, install the ground rainfall simulation device, according to the meteorological data, adjust the water volume of the shower and the spraying time of the shower through the water pump to simulate the actual rainfall; if the groundwater level rises sharply, the water outlet valve can be opened to recalibrate the groundwater level;

S5, place a mobile wheel load simulation device on the road surface, obtain the vertical load required for the test by adjusting the specification and quantity of weights, and spread the vertical load from the road surface layer to the road base layer through the loading wheel;

S6, the end of the connecting rod of the driving device is hinged with the rotating support through bolts, and the other end of the connecting rod is hinged with the slot of the rotating disc;

求得移动车轮荷载模拟装置的行进速度V；其中θ₁(x)表示卡槽与连杆的夹角，θ₂(x)表示旋转支撑与转动圆盘圆心的连线与连杆的夹角；S7, pull the mobile wheel load simulation device to the end farther from the driving device, turn on the motor and adjust the output frequency, control the angular velocity ω of the rotating disk, measure the distance x between the rotating support and the center of the rotating disk, and the connecting rod is hinged Radius R and connecting rod length L, the cosine law is used to obtain the angles θ ₁ (x) and θ ₂ (x), and then the velocity calculation formula

Obtain the travel speed V of the mobile wheel load simulation device; where θ ₁ (x) represents the angle between the slot and the connecting rod, and θ ₂ (x) represents the angle between the connecting line between the rotating support and the center of the rotating disk and the connecting rod ;

S8, one rotation of the rotating disc means that the mobile wheel load simulation device moves back and forth for one cycle. After the rotating disc is controlled to rotate several times, it stops; after a simulation experiment is completed, the experimental data is measured and collected to obtain the final settlement value of the roadbed and the crack width. , length and rut depth to complete the subgrade pavement deformation test.

The beneficial effects of the present invention are:

1. In the present invention, under the drive of the rotating disc, each time the moving wheel load simulation device moves back and forth, the vehicle speed must go through a process of gradually increasing from zero and gradually decreasing to zero, which can more accurately simulate the vehicle's speed. Start and brake. The velocity obtained by the moving wheel load simulation device is related to the angular velocity ω of the rotating disc and the radius R of the hinge. The size of the radius R at the hinge point can be changed by adjusting the hinge position of the connecting rod, and the size of the angular velocity ω of the rotating disc can also be changed by adjusting the frequency of the motor, so that the moving wheel load simulation device can obtain different running speeds, and the omnidirectional simulation of low and medium , High-speed vehicle subgrade-pavement deformation. At the same time, the present invention can also control the vertical load by adjusting the number and weight of the weights, and simulate the round-trip passage of vehicles with different axle loads. A device can simulate the influence of vehicles with different running speeds and different axle loads on the roadbed and pavement, which is more flexible.

2. The guide wheel used by the mobile wheel load simulation device is a spherical guide wheel, which can rotate freely in all directions. While ensuring that the mobile wheel load simulation device can reciprocate and load the roadbed and pavement along a fixed lateral direction, it does not limit its vertical direction. The movement in the direction of the road can restore the bumpy situation of the vehicle with the destruction of the roadbed.

3. Set a certain gap between the loading weight and the body screw. When the vehicle stops moving in a certain direction, the loading weight of the vehicle continues to move forward for a certain distance under the action of inertial force, and then is blocked by the screw to stop the movement. This process simulates the effect of the inertial force on the vehicle caused by the vehicle-mounted object under the influence of the vehicle's acceleration change, and solves the problem that the prior art does not consider the impact of the acceleration of the vehicle-borne object on the vehicle's force.

4. In the present invention, a transparent glass box is used to load the pavement-subgrade structure, and the overall deformation of the pavement subgrade can be observed more intuitively; The thickness and the thickness of each layer of soil in the subgrade are also subject to the actual situation, which can simulate the deformation of the subgrade-pavement to the maximum extent under the traffic load. The influence of the degree of deformation is closer to the actual situation.

5. The invention uses the simulation test method, which has the advantages of economy, easy control, easy inspection, safety, high efficiency, and observability. Adjust the design to save investment, time and energy.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a power loading system in an embodiment of the present invention.

Fig. 3a is a front view of the driving device in the embodiment of the present invention.

Fig. 3b is a left side view of the driving device in the embodiment of the present invention.

Fig. 4a is a front view of the moving wheel load simulation device in the embodiment of the present invention.

Fig. 4b is a top view of the mobile wheel load simulation device in the embodiment of the present invention.

Figure 4c is a right side view of the moving wheel load simulation device in the embodiment of the present invention.

FIG. 4d is a schematic structural diagram of a ball guide wheel in an embodiment of the present invention.

Fig. 5a is a schematic structural diagram when the water level probe touches the bottom of the water level pipe in the embodiment of the present invention.

FIG. 5b is a schematic structural diagram of a groundwater level measuring device when simulating a water level height according to an embodiment of the present invention.

FIG. 5c is a schematic diagram of the overall structure of the groundwater level measuring device in the embodiment of the present invention.

In the figure, 1. Subgrade pavement system; 11. Transparent glass box; 12. Subgrade; 13. Subgrade; 14. Pavement layer; 2. Driving device; 21. Motor; 22. Rotating disc; 23. Card slot; 24. Support; 25. Connecting rod; 3. Moving wheel load simulation device; 31. Top plate; 32. Ball guide wheel; 33. Loading shaft; 35. Loading wheel; 36. Loading plate; 37. Screw; 38. Weight Code; 39. Rotating support; 4. Groundwater level simulation device; 41. Water tank; 42. Connecting water pipe; 43. Inlet valve; 44. Water level pipe; 45. Water level probe; 46. Electric wire; 49. Line card; 50. Water outlet valve; 5. Ground rainfall simulation device; 51. Shower; 52. Beam; 53. Column; 54. Water pipe; 55. Water pump; 6. Measuring system ; 61. Settling plate.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

An embodiment of the present invention is a reciprocating loading test system for testing the deformation of subgrade and pavement. As shown in FIG. 1 , it includes a subgrade pavement system 1, a driving device 2, a mobile wheel load simulation device 3, a groundwater level simulation device 4, and a ground rainfall simulation device. 5 and the measurement system 6;

The roadbed pavement system 1 includes a transparent glass box 11, in which the ground base 12, the road base 13 and the pavement layer 14 are sequentially laid from bottom to top, and a measurement system 6 is installed in the roadbed pavement system 1; the transparent glass box 11 is 1m wide , 2m high, 4m long, made of FRP material with high strength and thickness of 0.05m. According to the specification, the thickness of the pavement layer 14 is controlled at 18-30cm, the thickness of the road base 13 is controlled at 30-80cm, and the thickness of the ground base 12 is controlled at 10-30cm.

As shown in Figures 2, 3a-3b, the driving device 2 and the moving wheel load simulation device 3 constitute a power loading system. The driving device 2 includes a rotating disk 22, and a clamping slot 23 is provided along the radial direction of the rotating disk 22. The disc 22 is driven by the motor 21 to rotate around the center of the circle; the frequency of the motor 21 is controlled by the microcomputer, and the rotating disc 22 is installed on the support 24 .

As shown in Figures 4a-4d, the mobile wheel load simulation device 3 includes a loading wheel 35, the loading wheel 35 is covered with tire rubber, the loading wheel 35 is in contact with the road surface layer 14, and a horizontally arranged top plate 31 is installed above the loading wheel 35. Two The loading wheel 35 is coaxially connected, and the middle of the shaft is fixedly connected to the top plate 31 through the loading shaft 33. The top plate 31 is provided with a bearing plate 36, and a weight 38 is placed on the bearing plate 36. The end of the top plate 31 close to the driving device 2 is provided with a rotating support 39. The rotating support 39 is hinged with one end of the connecting rod 25 through bolts, and the other end of the connecting rod 25 is connected with the hinge hole on the card slot 23; Up and down reciprocating movement is used to transmit the vertical load to the pavement layer 14 and then have an impact on the roadbed pavement system 1; the bolts are high-strength bolts, made of high-strength materials, with higher strength levels.

A vertical screw 37 is connected to the middle of the top plate 31 , the weight 38 is a circular ring and is sleeved on the outside of the screw 37 , a ball guide wheel 32 is nested in each of the four corners of the top plate 31 , and the ball guide wheel 32 is free relative to the top plate 31 . Rotation, the side wall of the spherical guide wheel 32 perpendicular to the movement direction of the mobile wheel load simulation device 3 is in contact with the inner wall of the transparent glass box 11 to ensure that the lateral trajectory of the mobile wheel load simulation device 3 acting on the pavement layer 14 is fixed, avoiding left and right offset, accurate The actual loading times at the same position of the pavement layer 14 can improve the test accuracy; at the same time, the spherical guide wheel 32 can weaken the restriction of the transparent glass box 11 on the actual motion trajectory of the vehicle, and ensure that the mobile wheel load simulation device 3 can be aligned along the fixed lateral direction. While the subgrade road is loaded by reciprocating movement, it does not limit its vertical movement, which can restore the bumpy situation of the vehicle with the destruction of the subgrade road.

There is a gap between the annular weight 38 and the screw 37. The width of the gap is in the range of 0.075m-0.15m. If it is smaller than this width, it is easy to collide. The central aperture of the weight 38 is 0.2m, and the diameter of the screw 37 is 0.05m. The simulation device 3 simulates that when the reciprocating motion of the vehicle changes at a certain point, such as stopping, accelerating, decelerating or starting, there is a gap between the weight 38 and the screw 37, so that the weight 38 continues to move for a certain distance under the action of the inertial force, and then it is connected to the bearing plate. The friction between 36 and the blocking action of the screw 37 stops the movement; this process simulates the effect of the inertial force on the vehicle caused by the vehicle-mounted object under the influence of the acceleration of the vehicle. Compared with the straight rod, the screw 37 has greater frictional resistance to the weight 38, and when the vehicle bumps up and down with road damage, the weight 38 is not easily thrown out.

For the connecting rod 25, its end speed is determined by the rotation speed of the rotating disc 22 and the distance R between the hinge and the center of the rotating disc 22; the clamping slot 23 is provided with a plurality of hinge holes with a spacing of 0.5m; the embodiment The radius of the middle rotating disc 22 is 1.5m, and there are three hinge holes on the card slot 23. The connecting rod 25 is hinged in different hinge holes. The connecting rod 25 is 2m long. The distance R between the end of the rod 25 and the center of the rotating disc 22 is changed to obtain different linear speeds, thereby changing the traveling speed of the simulated vehicle. The angular velocity of the rotating disc 22 .

As shown in Figures 5a-5c, the groundwater level simulation device 4 includes a water level pipe 44. The water level pipe 44 is placed at one end of the transparent glass box 11 away from the driving device 2 to avoid restricting the reciprocating movement of the mobile wheel load simulation device 3; the water level pipe The pipe wall of 44 is provided with a water filter hole with a diameter of 6-8mm, the outer wall is wrapped with 3-5 layers of gauze, the nozzle is higher than the transparent glass box 11, and the nozzle is equipped with a nozzle cover; 41 is connected with the bottom of the transparent glass box 11, a water inlet valve 43 is arranged on the communicating water pipe 42, and a vertical scale 47 is arranged above the water level pipe 44. The L"-shaped support rod 48 is placed outside the transparent glass box 11. The inverted "L"-shaped support rod 48 is 2.5m high. The top and bottom of the scale 47 are provided with line clips 49. The wire 46 is fixed by the wire clip 49. The lower end of the wire 46 The water level probe 45 is connected, and the water level probe 45 extends into the water level tube 44. By pulling the wire 46, the water level probe 45 moves up and down in the water level tube 44. The water level probe 45 passes through the wire inside the wire 46 and the water level gauge receiver. Connect, control the simulated water level height by adjusting the suspension height of the water level probe 45. The water level meter receiver adopts a single water level controller DZC-101, with an alarm, simple operation and low price.

The water level pipe 44 is made of PVC plastic pipe with a diameter of 50mm, the pipe wall is provided with a water filter hole with a diameter of 6-8mm, the outer wall is wrapped with 3-5 layers of gauze, and the binding is firm. Cover to prevent surface water and debris from entering. There is a water outlet at the bottom of the other end of the transparent glass box 11, and a water outlet valve 50 is arranged on the pipe connecting the water outlet.

Most of the existing groundwater level simulations are to inject water first, then measure with a groundwater level measuring instrument, and perform multiple groundwater level corrections according to the measurement results by injecting or releasing water. The groundwater level simulation device 4 of the present invention can pull the water level probe 45 up to the required simulated groundwater level, then open the water inlet valve 43 to inject water until the water level meter receiver sends an alarm signal, and then manually close the water inlet valve 43, The required simulated water level can be reached at one time; the operation is simple and time-saving.

The ground rainfall simulation device 5 includes a shower 51, a beam 52, a column 53, a water pipe 54, and a water pump 55; the column 53 is arranged at both ends of the transparent glass box 11, and the shower 51 is fixed on the beam 52 and suspended from the upper part of the roadbed pavement system 1 , the beam 52 is fixedly erected on two uprights 53, and two diagonal struts are welded between the beams 52 and the uprights 53 to form a stable triangular structure; ; The shower 51 is connected with the water tank 41 through the water pipe 54, and the water pipe 54 is provided with a water pump 55 to control the simulated rainfall.

The measurement system 6 includes a settlement plate 61 and a seam gauge, a rutting depth detection tool, and a tape measure for measuring the length of the crack, which are not shown in the figure. 8cm-12cm deep, measure the width of the crack; the rut depth detection tool includes a detection bar and a ruler.

The settlement plate 61 includes a base plate, which is made of reinforced concrete with a thickness of 300×300 (mm) and a thickness of 20 (mm). There is a measuring rod on the base plate. The measuring rod is made of round steel with a diameter of 12 mm. PVC plastic pipe with a diameter of 32mm, the upper port of the casing is provided with a plug; when not measuring The bottom elevation of the plate 61 is recorded, the initial value is recorded, and then the packing is compacted. After the experiment is completed, the pipe plug is opened to measure the elevation of the pipe head, and the difference between the two elevations is the settlement amount. The settlement plates 61 are buried in the positions of 10cm-15cm and 35cm-50cm below the pavement layer 14, and one is buried every 0.5m-1m, evenly distributed, to measure the settlement value of the road subgrade and pavement; The detection bar is placed horizontally above the rut, the ruler is vertically upright at the deepest position of the rut, and the reading of the ruler at the intersection with the bar is the depth of the rut; the tape measure is a direct measurement tool, which directly follows the crack extension direction in the later stage of crack generation. Measure the crack length.

The embodiment of the present invention is a reciprocating loading test method for testing the deformation of roadbed and pavement, which is specifically carried out according to the following steps:

S1, fix the water level pipe 44 vertically inside the transparent glass box 11, fill the transparent glass box 11 with soil for testing according to the actual conditions of the road pavement, lay the ground base 12, the road base 13 and the road surface 14, and install the measurement system 6;

S2, install the groundwater level simulation device 4; place the water level probe 45 just touching the bottom of the water level pipe 44, mark the wire 46 at the zero scale position at the bottom of the scale 47, and slowly pull the upper end of the wire 46 to make the wire 46 mark The scale corresponds to the simulated water level height, and the wire 46 is fixed with the line card 49 as the water level measurement state;

S3, open the water inlet valve 43, and slowly feed water through the water tank 41 and the connecting water pipe 42. When the actual water level touches the water level probe 45, the water level meter receiver emits a buzzer, closes the water inlet valve 43, stops water injection, and achieves the simulation required for the test. water level;

S4, install the ground rainfall simulation device 5, according to the meteorological data, adjust the water volume of the shower and the spraying time of the shower through the water pump 55 to simulate the actual rainfall; if the groundwater level rises sharply, the water outlet valve 50 can be opened to recalibrate the groundwater level;

S5, place the mobile wheel load simulation device 3 on the road surface, obtain the vertical load required for the test by adjusting the size and quantity of the weights 38, and spread the vertical load from the road surface layer 14 to the road base layer 13 through the loading wheel 35;

The weights 38 are accumulated to the loading weight required for the test, and the gravity is transmitted to the loading shaft 33 through the bearing plate 36 , and then to the loading wheel 35 . The weight 38 includes two types, large and small. The large weight weighs 15kg and the small weight weighs 5kg. The standard axle load of the road design is 100KN for a double wheel set and a single axle. The actual overload of more than 30% is regarded as a serious overload and will not be considered for the time being. Therefore, the actual simulated loading weight is between 100-130KN.

S6, the end of the connecting rod 25 of the driving device 2 is hinged with the rotating support 39 through the bolt, and the other end of the connecting rod 25 is hinged with the clamping slot 23;

求得移动车轮荷载模拟装置3的行进速度V。S7, pull the mobile wheel load simulation device 3 to the end farther from the driving device 2, turn on the motor 21 and adjust the output frequency, control the rotation speed of the rotating disk 22, ω is the angular velocity of the rotating disk 22, measure the rotation support 39 and the rotation The distance x between the centers of the disks 22, when the radius R at the hinge of the connecting rod 25 and the length L of the connecting rod 25 are known, the cosine theorem cosA=(b ² +c ² -a ² )/2bc, cosB= (c ² +a ² -b ² )/2ca, cosC=(a ² +b ² -c ² )/2ab gives the angle θ ₁ (x) and θ ₂ (x), where θ ₁ (x) represents the card The angle between the slot 23 and the connecting rod 25, θ ₂ (x) represents the angle between the connecting line between the rotary support 39 and the center of the rotating disk 22 and the connecting rod 25, as shown in Figure 2;

The traveling speed V of the moving wheel load simulation device 3 is obtained.

S8, one rotation of the rotating disk 22 means that the mobile wheel load simulation device 3 moves back and forth for one cycle, and the rotating disk 22 is controlled to rotate 5,000 times, and then stops; Settlement value, crack width, length and rut depth to complete the subgrade pavement deformation test.

The present invention considers the effect of heavy load and water environment on the embankment at the same time, through the driving device 2, the mobile wheel load simulation device 3, the groundwater level simulation device 4, and the ground rainfall simulation device 5, the load of the embankment and the effect of the water environment can be adjusted at the same time. The technical difficulty that the existing device cannot consider multiple factors at the same time is solved. In addition, the setting of the gap width between the annular weight 38 and the screw 37 can better simulate that when the speed of the load changes in a certain direction, the inertia continues to move forward for a certain distance, which solves the problem of the existing device. It is impossible to simulate the influence of inertia on the embankment during vehicle driving.

The present invention can simulate road layer filling and water environment according to road design scheme and local weather conditions before large-scale investment in road construction is carried out, predict the deformation of roadbed and pavement, change the design scheme in time according to the problems that occur, and save investment and time. and energy. At the same time, the bearing capacity of the road can be obtained through the test, and the current limiting design scheme can be proposed to make reasonable use of resources and achieve a certain degree of protection for the road. The invention can fill the soil according to the actual road layer conditions, so that various actual road projects that are damaged and cannot be operated normally can be simulated many times, and the road damage degree evaluation standard for the simulation experiment is designed.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A reciprocating movement loading test system for testing deformation of a roadbed and a road surface is characterized by comprising a roadbed and road surface system (1), a driving device (2), a moving wheel load simulation device (3) and a measurement system (6);

the roadbed and road surface system (1) comprises a transparent glass box (11), a road surface-roadbed structure model is laid in the transparent glass box (11), and a measurement system (6) is arranged in the road surface-roadbed structure model;

the driving device (2) comprises a rotating disc (22), a clamping groove (23) is formed in the radius direction of the rotating disc (22), a plurality of hinge holes are formed in the clamping groove (23), and the rotating disc (22) is driven to rotate around the circle center through a motor (21);

remove wheel load analogue means (3) including loading wheel (35), loading wheel (35) and road surface-roadbed structure model contact, roof (31) that the level set up are installed to loading wheel (35) top, two loading wheel (35) coaxial coupling, axle middle part is through loading axle (33) and roof (31) fixed connection, install on roof (31) and bear dish (36), bear and have placed weight (38) on dish (36), the one end that roof (31) are close to drive arrangement (2) is equipped with rotation support (39), rotation support (39) are articulated through the one end of bolt with connecting rod (25), the other end and the articulated eye on draw-in groove (23) of connecting rod (25) are connected.

2. The reciprocating movement loading test system for testing deformation of the roadbed and the road surface according to claim 1, wherein a vertical screw rod (37) is connected to the middle of the top plate (31), the weight (38) is in a circular ring shape and is sleeved outside the screw rod (37), a gap exists between the circular ring-shaped weight (38) and the screw rod (37), and the width of the gap is in a range of 0.075m-0.15 m.

3. The reciprocating motion loading test system for testing deformation of the roadbed and the road surface according to the claim 1 or 2, wherein a sphere guide wheel (32) is nested in each of four corners of the top plate (31), the sphere guide wheel (32) freely rotates relative to the top plate (31), and the side wall of the sphere guide wheel (32) which is vertical to the motion direction of the moving wheel load simulation device (3) is contacted with the inner wall of the transparent glass box (11).

4. The reciprocating motion loading test system for testing the deformation of the roadbed and the road surface according to the claim 1, characterized in that the test system further comprises an underground water level simulation device (4) which comprises a water level pipe (44), wherein the water level pipe (44) is arranged at one end, far away from the driving device (2), in the transparent glass box (11), the pipe wall of the water level pipe (44) is provided with a water filtering hole with the diameter of 6-8mm, the outer wall of the water level pipe is wrapped by 3-5 layers of gauze, the pipe orifice is higher than the transparent glass box (11), and a pipe orifice cover is arranged at the pipe orifice; link to each other water tank (41) and clear glass case (11) bottom through intercommunication water pipe (42), be equipped with inlet valve (43) on intercommunication water pipe (42), water pipe (44) top is equipped with graduation apparatus (47), graduation apparatus (47) top and bottom all are equipped with ply-yarn drill (49), be used for fixed electric wire (46), the lower extreme of electric wire (46) is connected with water level gauge head (45), water level gauge head (45) stretch into water pipe (44), water level gauge head (45) are connected with water level meter receiver through the inside wire of electric wire (46).

5. A reciprocal mobile loading test system for testing deformations of subgrade and pavement according to claim 1, characterized in that said scale (47) is fixedly supported by means of an inverted "L" -shaped strut (48), the inverted "L" -shaped strut (48) being placed outside the transparent glass box (11).

6. The reciprocating movement loading test system for testing deformation of the roadbed and the road surface according to the claim 1 or 4, characterized in that the test system further comprises a ground rainfall simulation device (5) comprising a shower head (51), a cross beam (52), a vertical column (53), a water pipe (54) and a water pump (55); the upright columns (53) are arranged at two ends of the transparent glass box (11), the shower head (51) is fixed on the cross beam (52) and is suspended at the upper part of the roadbed and pavement system (1), the cross beam (52) is fixedly arranged on the two upright columns (53), and two inclined support rods are welded between the cross beam (52) and the upright columns (53) to form a stable triangular structure; the bottom ends of the upright columns (53) are welded with heavy bases which are respectively arranged on two sides of the transparent glass box (11); the shower head (51) is connected with the water tank (41) through a water pipe (54), and a water pump (55) is arranged on the water pipe (54) to control the condition of simulated rainfall.

7. The reciprocating motion loading test system for testing deformation of the roadbed and the road surface as claimed in claim 1 or 4, wherein the bottom of the other end of the transparent glass box (11) is provided with a water outlet hole, and a pipeline connected with the water outlet hole is provided with a water outlet valve (50).

8. The reciprocating motion loading test system for testing deformation of roadbed and road surface according to claim 1, wherein the roadbed-roadbed structure comprises a foundation layer (12), a roadbed layer (13) and a pavement layer (14), which are sequentially laid in a transparent glass box (11) from bottom to top.

9. The reciprocating motion loading test system for testing deformation of the roadbed and the road surface is characterized in that the measuring system (6) comprises a settlement plate (61), a crack meter, a track depth detection tool and a measuring tape for measuring the length of a crack, wherein the settlement plate (61) comprises a base plate, a measuring rod is arranged on the base plate, a sleeve is arranged outside the measuring rod, and a plug is arranged at the upper end of the sleeve; the settlement plates (61) are buried at the positions with the depth of 10cm-15cm and the depth of 35cm-50cm below the road surface layer (14), and are buried at intervals of 0.5m-1m, uniformly distributed, and the settlement value of the road bed and the road surface is measured; the crack meter is embedded at the position 8cm-12cm deep of the pavement layer (14) to measure the width of a crack; the rut depth detection tool comprises a detection cross bar and a straight scale.

10. A reciprocating movement loading test method for testing deformation of a roadbed and a pavement is characterized by comprising the following steps:

s1, vertically fixing the water level pipe (44) inside the transparent glass box (11), filling soil for tests in the transparent glass box (11) according to the actual situation of a road pavement, laying a foundation layer (12), a pavement layer (13) and a pavement layer (14), and installing a measuring system (6);

s2, the water level measuring head (45) just touches the bottom of the water level pipe (44), the electric wire (46) at the zero scale position of the scale table (47) is marked, the upper end of the electric wire (46) is slowly pulled, the scale at the mark position of the electric wire (46) corresponds to the simulated water level height, and the electric wire (46) is fixed by a wire clamp (49) to be used as the water level measuring state;

s3, opening a water inlet valve (43), slowly feeding water through a water tank (41) and a communication water pipe (42), and when the actual water level touches a water level measuring head (45), sending buzzing by a water level meter receiver, closing the water inlet valve (43), stopping water injection, and achieving the simulated water level required by the test;

s4, installing a ground rainfall simulation device (5), and regulating the water quantity of the shower head and the spraying time of the shower head through a water pump (55) according to meteorological data to simulate the actual rainfall condition; if the underground water level is greatly increased, the water outlet valve (50) can be opened to recalibrate the underground water level;

s5, placing the moving wheel load simulation device (3) on the road surface, obtaining the vertical load required by the test by adjusting the specification and the number of the weights (38), and diffusing the vertical load from the road surface layer (14) to the road base layer (13) through the loading wheel (35);

s6, hinging the end part of a connecting rod (25) of the driving device (2) with a rotary support (39) through a bolt, and hinging the other end part of the connecting rod (25) with a clamping groove (23) of a rotating disc (22);

s7, pulling the moving wheel load simulation device (3) to the end far away from the driving device (2), turning on the motor (21), adjusting the output frequency, controlling the angular speed omega of the rotating disc (22), measuring the distance x between the rotary support (39) and the circle center of the rotating disc (22), the radius R of the hinged part of the connecting rod (25) and the length L of the connecting rod (25), and obtaining the angle theta by adopting the cosine law₁(x) And, theta₂(x) Then calculating the formula from the speed

Obtaining the traveling speed V of the moving wheel load simulation device (3); wherein theta is₁(x) Indicates the included angle theta between the clamping groove (23) and the connecting rod (25)₂(x) The included angle between the connecting line of the rotary support (39) and the circle center of the rotating disc (22) and the connecting rod (25) is shown;

s8, the rotating disc (22) rotates for a circle, namely the moving wheel load simulation device (3) reciprocates for a period, and the rotating disc (22) is controlled to rotate for multiple times and then stops; and after the primary simulation experiment is finished, measuring and collecting experimental data to obtain the final settlement value, the crack width, the length and the track depth of the roadbed pavement, and finishing the deformation test of the roadbed pavement.

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