Aeolian sand roadbed vibration wave excitation test device

Abstract

The utility model relates to the technical field of vibration tests, and particularly discloses an aeolian sand roadbed vibration wave excitation test device which comprises an excitation mechanism, a clamping mechanism and a data acquisition mechanism. The vibration excitation mechanism comprises a signal generator, a power amplifier and a vibration exciter; the clamping mechanism comprises a clamping plate, a bolt and a transverse plate. The data acquisition mechanism comprises an acceleration sensor, a dynamic data acquisition unit and a data processor. Through the arranged excitation mechanism, the excitation state of a train at different speeds and under different load conditions can be effectively simulated by adjusting the output frequency and excitation force, the damage condition of the aeolian sand improved soil under different excitation conditions can be accurately obtained, and the damage condition of the aeolian sand improved soil under different excitation conditions can be accurately detected through the arranged data collector. The dynamic response characteristics of the cement modified aeolian sand sample under the excitation condition can be effectively obtained, so that the internal change of the cement modified aeolian sand sample is judged.

Description

Technical Field

[0001] This invention belongs to the field of vibration testing technology, and specifically focuses on the vibration test of aeolian sand-modified soil as a roadbed material under the influence of vehicle cyclic dynamic load. Background Technology

[0002] The roadbed bears multiple loads from the track, vehicles, and pavement, transmitting these loads to the deeper layers of the foundation. Under the long-term vibration of vehicles, the roadbed will undergo irreversible deformation, i.e., plastic deformation. Therefore, when analyzing the negative effects of train loads, the cumulative plastic deformation caused by vehicle operation must be fully considered. Cumulative deformation refers to the irreversible deformation of the roadbed surface under repeated vehicle loads. Under the load of high-speed railway vehicles, different structural layers of the roadbed will experience differentiated cumulative deformation. If effective measures are not taken to control this, it will not only reduce the comfort of driving on the roadbed but may also cause train vibration, and in severe cases, even damage the track, posing a significant threat to traffic safety. As the load gradually increases, the skeletal structure of the soil will change, leading to permanent deformation.

[0003] Under the cyclic dynamic load of trains, high-speed railway subgrades are prone to problems, which in turn affect the safe operation of trains. Therefore, analyzing the dynamic characteristics of high-speed railway subgrade fill material under vibration loads is of great importance for improving the performance of subgrade soil and optimizing the design scheme of high-speed railway subgrades.

[0004] Given the vast scale and scope of highway construction projects in desert regions, the extensive use of traditional granular soil materials for roadbeds would not only create a huge demand for natural materials and lead to resource depletion due to over-exploitation, thus accelerating local ecological degradation, but also significantly increase construction costs and cause substantial unnecessary waste, which is detrimental to my country's current development. To promote high-quality and efficient railway construction in Northwest China, utilizing locally sourced aeolian sand—the most abundant resource in desert regions—as roadbed fill material during highway construction would greatly reduce material costs and benefit ecological environmental protection, thus possessing significant practical importance.

[0005] Aeolian sand is a type of ultrafine sand formed by wind transport from deserts and Gobi regions to alluvial plains, where it is deposited and naturally weathered. It is a special geological material widely distributed in the deserts and Gobi areas of Northwest my country. However, due to its non-cohesiveness, poor gradation, and high porosity, aeolian sand is not suitable for direct use as subgrade filler.

[0006] Soil consolidation technology offers a new solution for treating aeolian sand foundations using locally sourced materials and adapting to local conditions. By adding a solidifying agent to the aeolian sand, a series of physicochemical reactions occur between the agent and the water and mineral components in the sand. The resulting products fill the gaps between particles, enhancing the bonding between them and producing a solidification effect, thus forming a solidified aeolian sand foundation and realizing the resource utilization of desert aeolian sand. Current research indicates that solidifying agents for desert aeolian sand primarily use cement, lime stabilization, or the addition of inorganic binders such as fly ash, focusing on improving the road compressive strength of the solidified aeolian sand.

[0007] In practical road and railway engineering, inorganic materials such as silt and cement are often used to improve aeolian sand to meet the design requirements of the subgrade fill material. Cement hydrates fill the internal pores of the aeolian sand, making its structure more compact; cement hydrates also tightly bind the dispersed aeolian sand particles together to form a whole, significantly increasing its unconfined compressive strength. Improved aeolian sand exhibits good stability and superior mechanical properties, meeting the needs of engineering construction.

[0008] Currently, cement-modified aeolian sand has been used as a roadbed filler in some areas, but further research is needed on its stability as a high-speed railway roadbed filling material.

[0009] To simulate the cyclic dynamic load during train operation, this invention uses vibration waves for experimental research.

[0010] Vibrational wave excitation is less commonly used in the field of cement-to-aeolus sand conversion, but it has been widely applied in areas such as fractured coal and rock, oil reservoir permeability enhancement, and coalbed methane permeability enhancement. Under low-frequency vibration excitation, the coal and rock mass is subjected to repeated unidirectional excitation forces. Therefore, the loaded coal mass can be regarded as a structural body subjected to cyclic impact loads at a certain frequency and amplitude, which in turn causes a series of pores and fractures to develop and expand within the coal mass, resulting in changes in its microstructure and permeability.

[0011] Some scholars believe that vibration waves can effectively disturb the coal body, causing tension, compression and shearing effects on the coal and rock media during their propagation. As a result, the framework of the coal matrix undergoes elastic deformation, thereby increasing the micropores and microcracks in the coal body and expanding the diffusion and seepage channels.

[0012] The present invention aims to explore whether cement-modified aeolian sandy soil exhibits similar response characteristics to coal under the same excitation conditions as cement under vibration wave excitation.

[0013] To simulate the vibration impact on the roadbed during vehicle travel, a vibrator was used as the testing device in the experiment. The vibrator acts as a wave generator to excite the aeolian sand-modified soil sample. The specific frequency and amplitude are set by a signal generator to simulate the vibration waves generated during vehicle travel. A clamping device is installed below the vibrator to reproduce the vibration state experienced by the roadbed during vehicle travel. Therefore, we propose a vibration wave excitation test device for aeolian sand roadbed. Utility Model Content

[0014] The purpose of this invention is to investigate the vibration response characteristics of aeolian sand-modified soil samples under vibration wave excitation similar to that of a train.

[0015] To achieve the above objectives, the vibration wave excitation destructive testing mechanism of this utility model includes an excitation mechanism, a clamping mechanism, and a data acquisition mechanism. The excitation mechanism includes a signal generator, a power amplifier, and an exciter; the clamping mechanism includes a clamping plate, bolts, and a cross plate; and the data acquisition mechanism includes an acceleration sensor, a dynamic data acquisition unit, and a data processor.

[0016] The system includes a signal generator connected to a power amplifier, which in turn is connected to a vibrator. The vibrator provides vibration waves to the aeolian sand-modified soil sample. A clamping mechanism is used to fix the sample. An accelerometer is attached to the sample and connected to a dynamic data acquisition unit via a circuit. The dynamic data acquisition unit is then connected to a data processor.

[0017] The clamping mechanism is directly fixed to the horizontal plate below the vibrator by bolts, which can prevent the vibration from moving the aeolian sand-improved soil sample and affecting the experimental data.

[0018] The outer column of the vibrator is connected to the upper horizontal plate by a spring to reduce the impact of the clamping mechanism vibration on the test.

[0019] The vibrator includes a vibration chamber fixedly connected inside the aeolian sand-modified soil sample. Connecting plates are fixedly connected to both sides of the vibration chamber. A telescopic rod is fixedly connected to the top of the connecting plates. A side rod is fixedly connected to the bottom of the telescopic rod. A base plate is fixedly connected to the bottom of the side rod.

[0020] The bottom of the base plate is fixedly connected to a support plate, and the bottom of the support plate is fixedly connected to a caster wheel.

[0021] The telescopic rod is fixedly connected to a spring on its periphery, and the bottom of the spring is fixedly connected to the top of the side rod.

[0022] The vibration wave-excited destructive testing mechanism provided by this utility model has the following beneficial effects:

[0023] 1. The excitation mechanism of this utility model excitation test mechanism can effectively simulate the excitation state of a train under different speeds and loads by adjusting the output frequency and excitation force, and can accurately obtain the damage of aeolian sand-improved soil under different excitation conditions.

[0024] 2. The data acquisition device of the excitation test mechanism of this utility model can effectively acquire the dynamic response characteristics of cement-modified aeolian sand samples under excitation conditions, thereby judging the internal changes of cement-modified aeolian sand samples.

[0025] 3. The design of the vibration wave excitation test failure mechanism for cement-modified aeolian sand roadbed of this utility model can effectively explore whether cement-modified aeolian sand exhibits similar response characteristics to coal under the same excitation conditions under vibration wave excitation.

[0026] 4. The excitation test mechanism of this utility model is simple in structure, easy to operate, convenient to use, and highly practical. It provides strong data and theoretical support for studying the dynamic response characteristics of aeolian sand-improved soil as a roadbed material under the influence of vehicle cyclic dynamic load. Attached Figure Description

[0027] Figure 1 A schematic diagram of the vibration wave excitation and destruction mechanism provided in the embodiment of this utility model;

[0028] Figure 2 This is a detailed drawing of the vibrator in the mechanism of this utility model;

[0029] Figure 3 This is a detailed drawing of the clamping mechanism in the present invention.

[0030] Figure 4 This is a detailed view of the sample in the mechanism of this utility model.

[0031] Explanation of reference numerals in the attached drawings: 1. Aeolian sand-improved soil sample; 2. Accelerometer; 3. Signal generator; 4. Power amplifier; 5. Vibrator; 6. Clamping mechanism; 7. Dynamic data acquisition device; 8. Data processor; 101. Base plate; 102. Support plate; 103. Casters; 104. Connecting plate; 105. Vibration chamber; 106. Side rod; 107. Telescopic rod; 108. Spring. Detailed Implementation

[0032] like Figure 1 As shown, the vibration wave excitation test device for cement-modified aeolian sand roadbed of this utility model includes a signal generator 3, a power amplifier 4, a vibrator 5, a clamping mechanism 6, a dynamic data acquisition device 7, and a data processor 8, wherein the aeolian sand modified soil sample 1 is placed on the clamping mechanism 6.

[0033] This invention has a simple mechanism. It can generate a wave signal through the signal generator 3, which is then amplified by the power amplifier 4 and applied to the vibrator 5. The vibrator 5 starts to vibrate, thereby causing the aeolian sand-modified soil sample 1 to vibrate. The vibration is then detected by the acceleration sensor 2, and the internal response of the aeolian sand-modified soil sample 1 is monitored in real time by the dynamic data acquisition device 7. Finally, the damage signal of the aeolian sand-modified soil sample 1 is obtained through the data processor 8.

[0034] Aeolian sand-improved soil sample 1 is 100 mm. A 100mm cylinder.

[0035] Accelerometer 2 was attached to aeolian sand improved soil sample 1 using double-sided tape / Vaseline.

[0036] The vibration wave frequency generated by signal generator 3 is limited to between 20 and 80 Hz, which is similar to the vibration frequency of a high-speed train.

[0037] The clamping mechanism 6 is directly fixed to the horizontal plate below the vibrator 5 by bolts, which can prevent the vibration from moving the aeolian sand-improved soil sample and affecting the experimental data.

[0038] The upper part of the outer column of the vibrator 5 is connected to the upper horizontal plate by a spring to reduce the impact of the vibration of the clamping mechanism 6 on the test.

[0039] Step 1: Fix the clamping mechanism 6 to the steel plate below the vibrator 5 using threads. Take the aeolian sand improved soil sample 1, and then place the aeolian sand improved soil sample 1 on the clamping mechanism 6 to prevent it from shifting due to vibration; attach the accelerometer 2 to the surface of the aeolian sand improved soil sample 1 with double-sided tape.

[0040] Step 2: Connect the signal generator 3 to the power amplifier 4, connect the power amplifier 4 to the exciter 5, connect the accelerometer 2 to the dynamic data acquisition unit 7, turn on the dynamic data acquisition unit 7, and connect the dynamic data acquisition unit 7 to the data processor 8.

[0041] Step 3: Adjust signal generator 3, select a vibration wave with a frequency similar to that of a high-speed train, and start the equipment.

[0042] Step 4: The dynamic data acquisition device 7 acquires the received signals, and the data processor 8 saves, processes and analyzes the acquired data; based on multiple sets of experimental data, it is determined whether the cement-modified aeolian sandy soil exhibits similar response characteristics to other materials such as coal under the excitation of vibration waves.

[0043] The above description only outlines the basic principles and preferred embodiments of this utility model. These examples are merely illustrations of its application in testing facilities; specific applications require appropriate selection based on actual circumstances. Those skilled in the art can make many variations and improvements based on the above description, and these variations and improvements should fall within the protection scope of this utility model.

Claims

1. A vibration wave excitation test device for aeolian sand roadbed, characterized in that: include: Vibration mechanism, clamping mechanism and data acquisition mechanism, The excitation mechanism includes a signal generator, a power amplifier, and an exciter; The clamping mechanism includes an aeolian sand improved soil sample, a clamping plate, bolts, and a cross plate; The data acquisition mechanism includes an accelerometer, a dynamic data acquisition unit, and a data processor.

2. The vibration wave excitation test device for aeolian sand roadbed according to claim 1, characterized in that: The accelerometer was attached to the aeolian sand-modified soil sample using double-sided adhesive tape.

3. The vibration wave excitation test device for aeolian sand roadbed according to claim 1, characterized in that: The upper part of the outer column of the vibrator is connected to the upper horizontal plate by a spring.

4. The vibration wave excitation test device for aeolian sand roadbed according to claim 1, characterized in that: The clamping mechanism's clamping plate and cross plate are directly fixed to the cross plate below the vibrator by bolts.

5. The vibration wave excitation test device for aeolian sand roadbed according to claim 1, characterized in that: The vibrator includes a vibration chamber fixedly connected inside the aeolian sand improved soil sample. Connecting plates are fixedly connected to both sides of the vibration chamber. A telescopic rod is fixedly connected to the top of the connecting plate. A side rod is fixedly connected to the bottom of the telescopic rod. A base plate is fixedly connected to the bottom of the side rod.

6. The vibration wave excitation test device for aeolian sand roadbed according to claim 5, characterized in that: A support plate is fixedly connected to the bottom of the base plate, and a caster wheel is fixedly connected to the bottom of the support plate.

7. The vibration wave excitation test device for aeolian sand roadbed according to claim 5, characterized in that: A spring is fixedly connected to the periphery of the telescopic rod, and the bottom of the spring is fixedly connected to the top of the side rod.

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