CN114518292A - Model test device and test method for high-speed railway roadbed of inclined crossing karez - Google Patents

Abstract

The invention discloses a model test device and a test method for a high-speed railway roadbed of an inclined crossing karez, which comprises a reaction frame, a model device, a loading device, a monitoring system and a data acquisition system, wherein the reaction frame is arranged on the back of the model device; the model device comprises a concealed channel and a vertical shaft for simulating the karst well by adopting PVC pipes, and the influence of the uphill roadbed load and the dynamic load of a high-speed train on the structural stability of the roadbed is researched by setting the intersection angle between different concealed channels and the roadbed load central line and the buried depth of the concealed channel when the high-speed railway roadbed inclines to cross the karst well. The method can determine the influence mechanism of the intersection angle and the burial depth on the collapse mechanism of the shallow-buried well underdrain, evaluate the interaction influence range of the high-speed railway subgrade and the inclined crossing well underdrain under the dynamic load of the train, establish the foundation for evaluating the stability of the high-speed railway subgrade crossing different intersection angles and the buried depth well underdrain, and fill the technical blank in the aspect of indoor model test devices of the high-speed railway subgrade inclined crossing well underdrain region in China.

Description

Model test device and test method for high-speed railway subgrade across karez well

technical field

The invention relates to the technical field of geotechnical engineering, in particular to a model test device and a test method for a high-speed railway roadbed with an oblique spanning karez.

Background technique

Karez is an ancient groundwater conservancy irrigation project developed and utilized shallow groundwater for artesian irrigation in arid and semi-arid areas. It is mainly distributed in Xinjiang in my country. A karez is composed of four parts: an artificially excavated shaft, an underdrain with a certain longitudinal slope, an open channel for water conveyance on the ground, and a small reservoir. The underdrain is the main part of the karez, and the slope of the underdrain is smaller than the slope of the ground and the groundwater surface, and the groundwater can be drawn out of the ground by itself, so as to supply agricultural irrigation and residential use. The shafts are distributed along the culvert, generally at an interval of about 15-30m, and the bottom is connected to the culvert. The depth is generally 5-60m, and the maximum can reach more than 80m, mainly for ventilation and soil drainage during construction.

Karezes all over the world are dying to varying degrees. The main reason is the collapse of karezes caused by various natural and human factors, especially the collapse of unreinforced culverts. In engineering research, the karst well has a structure similar to mine goaf, karst cave and so on. For the karez that is crossed by the high-speed railway subgrade, the unreinforced culvert is very likely to collapse under the load of the subgrade and the load generated by the train running, causing damage to the connected subgrade, which in turn affects the stability of the upper high-speed railway subgrade and the safety of trains. Therefore, it is necessary to study the stability of the karez under the load of the high-speed rail line.

The new high-speed railway foundation project often crosses over the karez well ditch inclined and crossed. For the karez, when the high-speed railway foundation is overlaid on the karez underdrain at different intersection angles, the effect of external force is different, which will make the karez produce different mechanical responses. Therefore, it is necessary to clarify the influence mechanism of the intersection angle on the interaction between the karez well underdrain and the subgrade above, so as to establish a stability evaluation method for crossing the karez well underdrain with different intersection angles, and determine the reinforcement treatment range of the inclined cross-karez high-speed railway subgrade.

At present, there is no design scheme for high-speed railway subgrade in the karez area in my country. The technology of the present invention can fill the technical gap of the indoor model test device in the high-speed railway subgrade in the karez area in my country, and contribute to the construction of high-speed railways in the northwest region of China and other countries in the future. .

SUMMARY OF THE INVENTION

In view of the above-mentioned problems in the prior art, the present invention aims to provide a model test device and test method for a high-speed railway subgrade across the karez well, which are used to study the collapse of the karez well underdrain at different angles of intersection between the underdrain and the line and the depth of the underdrain to the upper foundation. Then, the stability of the subgrade structure of the cross-karez high-speed railway was analyzed, and the reinforcement treatment range required for the subgrade of the Kanerjing high-speed railway that inclined across the high-speed train under the dynamic load of the high-speed train was determined. There is a technical gap in the model test device.

In order to achieve the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is as follows:

Provided is a joint structure for a tunnel corrugated plate support structure, which includes a reaction force frame, a model device, a loading device, a monitoring system and a data acquisition system;

The model device includes a model box, and the model box is provided with a model subgrade and a model foundation arranged below the model subgrade, and the model foundation is provided with a karez well underdrain and a karez well shaft simulated by a PVC pipe; θ ranges from 0 to 90°, under different intersection angles θ, the collapse failure and deformation laws of karez well underdrains are obtained;

The loading device is connected with the reaction frame, and the loading device is used to apply static and dynamic loads to the model subgrade;

The monitoring system includes displacement gauges arranged on the surface of the model roadbed and model foundation, strain gauges arranged on the surface of the karez well underdrain and karez well shaft, an earth pressure cell arranged in the model roadbed and the model foundation, and a water content meter arranged in the model foundation; The data acquisition system is electrically connected with the monitoring system.

Further, the model box includes a frame made of profiled steel and transparent tempered glass arranged on the side wall of the frame; the inner size of the model box is 2.0m×2.0m×1.5m, and the thickness of the transparent tempered glass is 30mm.

Further, the loading device includes a jack for applying static load to the model subgrade and a servo vibration exciter for applying dynamic load to the model subgrade. The dynamic load frequency of the vibrator is 5Hz, and the dynamic load dynamic stress amplitude is 10kN.

Further, the loading device further includes a loading plate with a concrete cushion on the lower surface, and the jack and the servo vibration exciter apply static and dynamic loads to the model roadbed through the loading plate.

Further, a water bladder with a remote on-off valve is arranged in the karez underdrain and the karez shaft.

Further, a buffer device is provided between the model foundation and the inner wall of the model box. The buffer device includes a buffer pad and a rigid baffle. The two side walls of the buffer pad are respectively in contact with the model foundation side wall and the rigid baffle side wall. One side wall is in contact with the inner wall of the model box.

This scheme also provides a test method for the model test device of the high-speed railway subgrade across the karez well, which is used to study the influence of different culvert and line intersection angles and the depth of the culvert to the upper foundation on the collapse mechanism of the karez well culvert, and then analyze the cross-karez high-speed railway. The stability of the subgrade structure is determined, and the reinforcement treatment range required for the subgrade of the Kanerjing high-speed railway that is inclined across the high-speed train under the dynamic load of the high-speed train is determined, and the method includes the following steps:

S1: Model size calculation

Set the model test similarity ratio on the basis of no boundary effect, and calculate the size of the model roadbed, model foundation and PVC pipe filled in the model box and the quality of the required filling according to the similarity ratio;

S2: Filling sample

The falling sand method is used for layered filling. After each layer of similar materials is filled, it is leveled and compacted to ensure that the dry density of each layer of soil is the same during the filling process; at the designed burial depth, PVC pipes are placed in the model foundation. Simulate the karez well underdrain or shaft; the intersection angle between the karez well underdrain and the line is θ, and the intersection angle θ is 0 to 90°. Water bladders are pre-placed in the PVC pipes of the simulated karez well underdrains. After the model foundation is filled, the water bladders are drained to obtain no support. Null guards simulate karez underdrains;

S3: Deploy monitoring system

Earth pressure cells and water content gauges are embedded in the model subgrade and model foundation, strain gauges are installed on PVC pipes, and displacement gauges are installed on the surface of the model subgrade and model foundation; The system is electrically connected; the data acquisition system tests whether the reading of the monitoring system is normal, if it is normal, go to step 4, otherwise, check until the reading is normal;

S4: Arrange the loading device

The loading device is connected with the reaction frame, and a layer of concrete cushion is arranged on the loading plate;

S5: Static load loading

The jack loads the sample, and the data is recorded every 1 min. When the jack is loaded higher than the train load, the loading is stopped, and the data is recorded and sorted;

S6: dynamic loading

The vibration exciter loads the sample in the form of a sine wave with an amplitude of 5kN and a frequency of 10Hz to simulate the load of a high-speed train, observe and record the data of the monitoring system, until the PVC pipe is damaged or the number of power cycles reaches 10,000, the vibration exciter stops. sample loading;

S7: uninstall;

S8: According to the physical parameters collected by the monitoring system, analyze and determine the interaction of the karez on the high-speed railway subgrade.

Step S8 further includes:

The soil pressure distribution in the model subgrade and the model subgrade structure during the dynamic load stage is obtained from the earth pressure box data, and then the attenuation law of the dynamic stress in the horizontal and vertical directions is obtained, and the influence distribution and action range of the high-speed railway load on the high-speed railway subgrade are obtained. ;

According to the displacement parameters collected by the displacement meter, the settlement of the model subgrade and the model subgrade during the dynamic load stage is obtained, and the influence of the existence of the karez on the settlement of the subgrade is obtained;

According to the strain parameters collected by the strain gauges, the strains of the karez wells and karez wells in the dynamic load stage were obtained, and the influence of the train load on the deformation of the karez wells was obtained.

Further, according to the model test results, the method to determine the influence range of the high-speed railway subgrade slope crossing the karez interaction is as follows:

Analyze the attenuation laws σx and σy of dynamic stress in the horizontal and vertical directions, and obtain the influence range s1 of the high-speed rail load; analyze the settlement d of the karez well foundation under the dynamic load, and obtain the influence s2 of the existence of the karez on the settlement of the subgrade; Position the karez underdrain Qy and the deformation quantity Qx of the shaft, obtain the influence s3 of the train load on the deformation of the _karez , and obtain the _karez shaft and underdrain under the train load when the distance is Scr. The maximum horizontal and vertical dynamic stress; dy is the settlement of the foundation surface, dymax is the maximum settlement; Q is the deformation of the karez in different positions monitored, and the maximum deformation of the underdrain at the cross center position is Qmax; the deformation of the shaft is taken as 10% of shaft diameter (Sd);

When σ _x <0.1σ _Xmax , σ _y <0.1σ _Ymax , d _y <0.1d _{y max} , Q _y <0.1Q _{y max} and Qx<0.1Sd , determine Scr as the critical distance, and move outside the critical distance The influence of the load on the karez can be ignored, and the influence range of the dynamic load is determined.

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention can effectively simulate the working conditions of cross-karez high-speed railway subgrade under different working conditions such as karez crossing angles and burial depths indoors, and obtain more accurate data through testing components; The collapse failure and deformation laws of culverts, the influence of train loads on the deformation of the karez, the influence of the existence of culverts on the settlement of the subgrade, the attenuation law of dynamic stress in the foundation, and the morphological evolution process of the soil arching effect of the karez.

2. The present invention can comprehensively evaluate the interaction influence range of the high-speed railway subgrade across the karez in combination with the test results, determine the required treatment area for the inclined cross-karez subgrade and the foundation, and lay a good theoretical foundation for the construction of the high-speed railway subgrade in the actual karez area. The device and the process are relatively simple and convenient to operate in the laboratory.

Description of drawings

FIG. 1 is a schematic structural diagram of a model test device for a high-speed railway subgrade across a karez well.

Among them, 1, model box; 2, model roadbed; 3, model foundation; 4, karez well underdrain; 5, karez well shaft; 6, reaction force frame; 7, loading device; 8, displacement gauge; 9, strain gauge; 10, Earth pressure cell; 11. Moisture meter; 12. Loading plate.

Detailed ways

The specific embodiments of the present invention are described below to facilitate those skilled in the art to understand the present invention, but it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes Such changes are obvious within the spirit and scope of the present invention as defined and determined by the appended claims, and all inventions and creations utilizing the inventive concept are within the scope of protection.

As shown in FIG. 1 , the present invention provides a model test device for a high-speed railway subgrade across a karez well, including a reaction force frame 6 , a model device, a loading device 7 , a monitoring system and a data acquisition system.

Wherein, the model device includes a model box 1, and the model box 1 is composed of a frame and transparent tempered glass arranged on the side wall of the frame, and its size is based on the absence of boundary effects.

The model box 1 is provided with a model subgrade 2 and a model foundation 3 arranged below the model subgrade 2. The model foundation 3 is provided with a karez well 4 and a karez well shaft 5 simulated by PVC pipes; for the convenience of the model test, the size of the test models is similar The ratio is preferably 20. According to the similarity ratio, the width of the surface layer of the subgrade designed for the standard section is 8.2m, the width of the bottom surface of the embankment is 23.2m, the height is 5m, and the slope of the side slope is 1:1.5, then the surface width of the corresponding model subgrade 2 is 41cm, and the bottom surface of the embankment is 41cm. The width is 116cm and the height of the roadbed is 25cm. The size of the model box 1 is as follows: the height of the model box 1 is the height of the foundation plus the height of the roadbed and a certain safety space is reserved. Therefore, the height of the model box 1 is 1.5m, and the width and length of the model box 1 are the length of the base surface, which is 2m. Therefore, the actual size of the model box 1 selected is 2.0m×2.0m×1.5m (length×width×height). In addition, the transparent tempered glass is 30mm thick. The soil layers in the Karez area are mostly clay sand, and the clay sand material is used as model subgrade 2 and model foundation 3 in the model test.

The use of PVC pipe to simulate karez is due to the high tensile strength of PVC pipe, but it will be damaged under high pressure, which is in line with the characteristics of karez. A water bladder with a remote switch valve is arranged in the PVC pipe, and the diameter of the PVC pipe and the water bladder is 7.5 cm to simulate a karez well 4 or shaft 5 with an actual diameter of 1.5 m. When filling the model, use a water bladder to fill the PVC pipe in advance to prevent it from being damaged before the model is formed. After the model is filled, the simulation of karez well 4 is completed by discharging the water in the water bladder by opening the remote switch valve.

The loading device 7 is connected with the reaction force frame 6, and the loading device 7 is used to apply static and dynamic loads to the model subgrade 2; the loading device 7 is divided into a static load device and a dynamic load device. The static load device and the dynamic load device apply static and dynamic loads to the model subgrade 2 through the loading plate 12, and a layer of concrete cushion is arranged under the loading plate 12 to make the load generated by the loading device 7 evenly distributed on the subgrade. above. A buffer device is arranged between the model foundation 3 and the inner wall of the model box 1. The buffer device includes a buffer pad and a rigid baffle. The buffer pad can be a foam board. Contact, the other side wall of the rigid baffle is in contact with the inner wall of the model box 1. First, a flexible buffer material such as foam board is arranged on the edge of the foundation soil, and then a rigid baffle is arranged outside the flexible buffer material to prevent the dynamic load from being applied. The exciter caused damage to the test device during the process.

Preferably, but not limitedly, a jack is used to load the sample in static load loading, data is recorded every 1 min, and the loading is stopped when the load is slightly higher than the train load. The dynamic load is loaded with a servo exciter device, which consists of a hydraulic servo loading system and a loading actuator. The size of the loading plate 12 is 2.0m × 0.3m × 0.03m (length × width × height), and the maximum dynamic load loading value is It can reach 200kN, and the maximum dynamic loading frequency can reach 100Hz, which can fully simulate the working condition of high-speed railway subgrade under dynamic load. The sample is loaded in the form of sinusoidal cyclic loading by using a vibration exciter, and the data is observed and recorded for each loading cycle, and the loading is stopped at this time.

The monitoring system includes a displacement gauge 8 arranged on the surface of the model roadbed 2 and the model foundation 3, a strain gauge 9 arranged on the surface of the karez well 4 and the karez well shaft 5, an earth pressure cell 10 arranged in the model roadbed 2 and the model foundation 3, and the The water content meter 11 in the model foundation 3; the data acquisition system is electrically connected with the monitoring system, and the data acquisition system can use a computer.

Using displacement gauge 8, strain gauge 9, earth pressure cell 10, moisture gauge 11 and other sensors, static data acquisition instrument and corresponding test and analysis system to measure the changes of displacement, earth pressure and moisture content under the action of self-weight and subgrade load law.

The present invention also provides a test method for a model test device for a high-speed railway roadbed with an oblique spanning karez, comprising the following steps:

S1: Model size calculation

The model test similarity ratio is set on the basis of no boundary effect, and the size of the model subgrade 2, model foundation 3 and PVC pipe filled in the model box 1 and the quality of the required filling are calculated according to the similarity ratio. For the influence of the intersection angle between the subgrade load centerlines on the stability of the subgrade structure, the culvert can be arranged at different angles such as 0 to 90°. H can choose 3 to 7 times the diameter of the culvert; the distance between the culvert and the load center position on the cross section can be determined according to the actual needs of the culvert at the simulated work point.

S2: Filling sample

The falling sand method is used for layered filling. After each layer of similar materials is filled, it is leveled and compacted to ensure that the dry density of each layer of soil is the same during the filling process. Specifically, after each layer of similar materials is filled, an initial Leveling: After leveling, lay a plank on the soil surface, and use a fixed mass of weights to compress the similar materials to be filled through the force transmission of the plank. Adjust the height difference with a spirit level to keep the filling surface flat; under the designed burial depth, place the PVC pipe in the model foundation 3 to simulate the karez 4 or shaft 5; After the foundation 3 is filled, the water bladder is drained to obtain an unsupported cavity to simulate the karez well 4;

S3: Deploy monitoring system

The earth pressure cell 10 and the water content meter 11 are embedded in the model subgrade 2 and the model foundation 3, the strain gauge 9 is installed on the PVC pipeline, and the displacement gauge 8 is installed on the surface of the model subgrade 2 and the model foundation 3; 11. The strain gauge 9 and the displacement gauge 8 are electrically connected to the data acquisition system; the data acquisition system tests whether the reading of the monitoring system is normal, if it is normal, go to step 4, otherwise, check until the reading is normal;

S4: Arrange the loading device 7

Put the loading part on the cement backing plate, so that the load generated by the loading device 7 is evenly distributed on the roadbed, and the thickness of the backing plate should be 50mm;

S5: Static load loading

The jack loads the sample, the loading rate should not be too fast, and the data is recorded at an interval of 1 min. When the jack is loaded to a higher value than the train load, the loading is stopped, and the data is recorded and sorted;

S6: dynamic loading

The vibration exciter loads the sample in the form of a sine wave with an amplitude of 5kN and a frequency of 10Hz to simulate the load of a high-speed train, observe and record the data of the monitoring system, until the PVC pipe is damaged or the number of power cycles reaches 10,000, the vibration exciter stops. sample loading;

S7: Unloading; attention should be paid to safety, and it should be ensured that the switch of the loading device 7 is turned off before unloading;

S8: According to the physical parameters collected by the monitoring system, analyze and determine the interaction of the karez on the high-speed railway subgrade.

Step S8 further includes: after the end of the test, the earth pressure box 10 data obtains the earth pressure distribution in the model subgrade 2 and the model foundation 3 structure during the dynamic load stage, and then obtains the attenuation law of the dynamic stress in the horizontal direction and the vertical direction, and obtains: The distribution and scope of the influence of high-speed railway load on the high-speed railway subgrade;

According to the displacement parameters collected by the displacement meter 8, the settlement of the model subgrade 2 and the model subgrade 3 in the dynamic load stage is obtained, and the influence of the existence of the karez on the settlement of the subgrade is obtained;

According to the strain parameters collected by the strain gauge 9, the strains of the karez well 4 and the karez well shaft 5 during the dynamic load stage are obtained, and the influence of the train load on the deformation of the karez well is obtained; the model test results are used to evaluate the influence range of the high-speed railway subgrade inclination across the karez well. .

Further, according to the model test results, the method to determine the influence range of the high-speed railway subgrade slope crossing the karez interaction is as follows:

Analyze the attenuation laws σx and σy of dynamic stress in the horizontal and vertical directions, and obtain the influence range s1 of the high-speed rail load; analyze the settlement d of the karez well foundation under the dynamic load, and obtain the influence s2 of the existence of the karez on the settlement of the subgrade; Position the karez underdrain Qy and the deformation quantity Qx of the shaft, obtain the influence of the train load on the deformation of the _karez , s3, and obtain the distance Scr. The _karez shaft and underdrain under the train load do not need to be reinforced; The maximum horizontal and vertical dynamic stress; dy is the settlement of the foundation surface, dymax is the maximum settlement; Q is the deformation of the karez in different positions monitored, and the maximum deformation of the underdrain at the cross center is Qmax; the deformation of the shaft is taken as 10% of shaft diameter (Sd);

When σ _x <0.1σ _Xmax , σ _y <0.1σ _Ymax , d _y <0.1d _{y max} , Q _y <0.1Q _{y max} and Qx<0.1Sd , determine Scr as the critical distance, and move outside the critical distance The influence of the load on the karez can be ignored, and the influence range of the dynamic load is determined.

To sum up, the present invention can effectively simulate the working conditions of cross-karez high-speed railway subgrade under different working conditions such as karez crossing angles and burial depths indoors, and obtain relatively accurate data through testing components; The collapse failure and deformation laws of the karez 4, the influence of train loads on the deformation of the karez, the influence of the existence of the culvert on the settlement of the subgrade, the attenuation law of the dynamic stress in the foundation, and the morphological evolution of the karez soil arch effect, etc., can be combined with the test results. Assessing the influence scope of the high-speed railway subgrade inclination crossing the karez, and determining the treatment area for the inclined crossing karez subgrade and foundation, which lays a good theoretical foundation for the construction of the high-speed railway subgrade in the actual karez area. Operate indoors.

Claims (10)

1. the model test device of the high-speed railway roadbed of the oblique span karez, is characterized in that, comprises reaction force frame, model device, loading device, monitoring system and data acquisition system; The model device includes a model box, and the model box is provided with a model roadbed and a model foundation arranged under the model roadbed. The intersection angle of the line is θ, and the intersection angle θ is 0-90°. Under different intersection angles θ, the collapse failure and deformation laws of the karez well underdrain are obtained; The loading device is connected with the reaction force frame, and the loading device is used to apply static and dynamic loads to the model roadbed; The monitoring system includes displacement gauges arranged on the surface of the model roadbed and model foundation, strain gauges arranged on the surface of the karez well underdrain and karez well shaft, an earth pressure cell arranged in the model roadbed and the model foundation, and a water content meter arranged in the model foundation; The data acquisition system is electrically connected with the monitoring system. 2. the model test device of the high-speed railway roadbed of the inclined span karez according to claim 1, is characterized in that, described model box comprises the frame that material is profiled steel and the transparent tempered glass that is arranged on the frame side wall; The internal size is 2.0m×2.0m×1.5m, and the thickness of transparent tempered glass is 30mm. 3 . The model test device for the high-speed railway subgrade of an inclined cross karez according to claim 2 , wherein the material of the model subgrade and the model foundation is clay sand. 4 . 4. The model test device for the high-speed railway subgrade of the inclined-span karez according to claim 3, wherein the loading device comprises a jack for applying static load to the model subgrade and a jack for applying dynamic load to the model subgrade. Servo exciter. The servo exciter is used to simulate the dynamic load imposed by the high-speed railway train on the model subgrade. The dynamic load frequency of the servo exciter is 5Hz, and the dynamic load dynamic stress amplitude is 10kN. 5. the model test device of the high-speed railway roadbed of the inclined-span karez according to claim 4, is characterized in that, described loading device also comprises the loading plate that the lower surface is provided with concrete cushion, the jack and the servo vibration exciter are loaded by loading The slab applies static and dynamic loads to the model subgrade. 6 . The model test device for the high-speed railway roadbed of the oblique spanning karez according to claim 1 , wherein a water bladder with a remote on-off valve is provided in the karez underdrain and the karez shaft. 7 . 7. The model test device for the high-speed railway roadbed of the inclined-span karez according to claim 4, wherein a buffer device is provided between the model foundation and the inner wall of the model box, and the buffer device comprises a buffer pad and a rigid block The two side walls of the cushion pad are respectively in contact with the side wall of the model foundation and the side wall of the rigid baffle, and the other side wall of the rigid baffle is in contact with the inner wall of the model box. 8. A test method of the model test device of the high-speed railway roadbed of the inclined span karez according to claim 1～7, is characterized in that, comprises the following steps: S1: Model size calculation Set the model test similarity ratio on the basis of no boundary effect, and calculate the size of the model roadbed, model foundation and PVC pipe filled in the model box and the quality of the required filling according to the similarity ratio; S2: Filling sample The falling sand method is used for layered filling. After filling of each layer of similar materials, it is leveled and compacted to ensure that the dry density of each layer of soil is the same during the filling process; under the designed burial depth, PVC pipes are placed in the model foundation. Simulate a karez well underdrain or shaft, the intersection angle between the karez well underdrain and the line is θ, and the intersection angle θ is 0 to 90°; water bladders are pre-placed in the PVC pipes of the simulated karez well underdrains, and after the model foundation is filled, the water bladders are drained to obtain an unsupported The guard hole simulates the karez underdrain; S3: Deploy monitoring system The soil pressure cell and water content meter are embedded in the model subgrade and the model foundation, the strain gauge is installed on the PVC pipeline, and the displacement gauge is installed on the surface of the model subgrade and the model foundation; The system is electrically connected; the data acquisition system tests whether the reading of the monitoring system is normal, if it is normal, go to step 4, otherwise, check until the reading is normal; S4: Arrange the loading device The loading device is connected with the reaction frame, and a layer of concrete cushion is arranged on the loading plate; S5: Static load loading The jack loads the sample, and the data is recorded every 1min. When the jack is loaded higher than the train load, the loading is stopped, and the data is recorded and sorted; S6: dynamic loading The vibration exciter loads the sample in the form of a sine wave with an amplitude of 5kN and a frequency of 10Hz to simulate the load of a high-speed train, observe and record the monitoring system data, until the PVC pipe is damaged or the number of power cycles reaches 10,000, the exciter stops. sample loading; S7: uninstall; S8: According to the data collected by the monitoring system, analyze and determine the interaction between the karez and the high-speed railway subgrade. 9. the test method of the model test device of the high-speed railway roadbed of the inclined span karez according to claim 8, is characterized in that, step S8 further comprises: The soil pressure distribution in the model subgrade and the model subgrade structure during the dynamic load stage is obtained from the earth pressure box data, and then the attenuation law of the dynamic stress in the horizontal and vertical directions is obtained, and the influence distribution and action range of the high-speed railway load on the high-speed railway subgrade are obtained. ; According to the displacement parameters collected by the displacement meter, the settlement of the model subgrade and the model subgrade during the dynamic load stage is obtained, and the influence of the existence of the karez on the settlement of the subgrade is obtained; According to the strain parameters collected by the strain gauges, the strains of the karez wells and karez wells in the dynamic load stage were obtained, and the influence of the train load on the deformation of the karez wells was obtained. 10. the test method of the model test device of the high-speed railway subgrade of the high-speed railway subgrade of inclined spanning karez according to claim 9, it is characterized in that, according to model test result, determine that the method for high-speed railway subgrade inclination spanning the karez well interaction influence range is: Analyze the attenuation laws σx and σy of dynamic stress in the horizontal and vertical directions, and obtain the influence range s1 of the high-speed rail load; analyze the settlement d of the karez well foundation under the dynamic load, and obtain the influence s2 of the existence of the karez on the settlement of the subgrade; Position the karez underdrain Qy and the deformation quantity Qx of the shaft, obtain the influence s3 of the train load on the deformation of the _karez , and obtain the _karez shaft and underdrain under the train load when the distance is Scr. The maximum horizontal and vertical dynamic stress; dy is the settlement of the foundation surface, dymax is the maximum settlement; Q is the deformation of the karez in different positions monitored, and the maximum deformation of the underdrain at the cross center is Qmax; the deformation of the shaft is taken as 10% of shaft diameter (Sd); When σ _x <0.1σ _Xmax , σ _y <0.1σ _Ymax , d _y <0.1d _{y max} , Q _y <0.1Q _{y max} and Qx<0.1Sd, determine Scr as the critical distance, and move outside the critical distance The influence of the load on the karez can be ignored, and the influence range of the dynamic load is determined.

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