CN216525270U - Confining pressure loading test device suitable for fatigue test - Google Patents
Confining pressure loading test device suitable for fatigue test Download PDFInfo
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- CN216525270U CN216525270U CN202122797603.7U CN202122797603U CN216525270U CN 216525270 U CN216525270 U CN 216525270U CN 202122797603 U CN202122797603 U CN 202122797603U CN 216525270 U CN216525270 U CN 216525270U
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Abstract
The utility model provides a confined pressure loading test device suitable for fatigue test, includes the experimental model box of railway ballast and confined pressure control system, confined pressure control system include the utricule, the utricule include one-level hydroecium, second grade hydroecium, inlet tube one and inlet tube two, the experimental model box of railway ballast in be equipped with the detachable backup pad, the backup pad be located between two second grade hydroeciums. After adopting the structure, the utility model has the advantages that: the device can be used for measuring mechanical characteristic changes of the ballast bed after cyclic load action under different lateral confining pressure and vertical load action conditions in a laboratory, accumulating sedimentation rules and particle crushing conditions, controlling water pressure in the capsule body in regions by the aid of the accessible, and controlling lateral active pressure of the capsule body on a sample in a layered mode in different directions, so that fine simulation of stress conditions of each working condition environment of the ballast bed is realized. The railway ballast test model box is formed by assembling a bottom plate and detachable side plates with the same four surfaces through bolts, and can be used for easily changing samples and cleaning a box body.
Description
Technical Field
The utility model relates to the technical field of confining pressure loading tests, in particular to a confining pressure loading test device suitable for a fatigue test.
Background
The ballast stone is widely applied to ballast tracks as an irreplaceable track bed material, and plays an important role in working links such as train load transmission, track bed accumulated water discharge, sleeper position fixing and the like. However, after a long-term cyclic reciprocating action of train load, the railway ballast is often subjected to different degradation phenomena such as sharp-corner breakage, particle fracture, surface abrasion and the like. Research has shown that the accumulation of the dirt on the track bed caused by the wear of the surface of the ballast and the degradation of the gradation of the track bed not only weaken the mechanical property of the track bed, but also easily cause serious diseases such as uneven settlement of the track bed and geometric instability of track lines, and finally indirectly affect the safety of train running and the comfort of passengers.
In order to explore the mechanical property change, the accumulated sedimentation rule and the particle crushing condition of the ballast bed under the action of cyclic load. In recent years, research on mechanical property analysis of a track bed under the action of train cyclic load is increasing. Most of crushed stone railway ballast cyclic load fatigue test model boxes used in the existing research are too simple in structure, and the side plates of the model box body can not realize movable in different areas, so that the lateral active stress in different areas can not be provided for the side surface of a railway ballast sample. In the model box body, four rigid metal plates are used as side plates and directly welded to a rigid metal bottom plate, and the side plates at the periphery of the model box body are immovable rigid plates in the test process, so that a lateral active stress strain state cannot be provided for a sample, and a rigid lateral limit is substituted; in addition, there are few experimental models that improve the former by replacing the rigid immovable side plate with a movable side plate, and the lateral pressure is provided by a jack, and the movable side plate is displaced and stressed by the concentrated jacking force of the jack, so that the lateral pressure is indirectly applied to the sample. Because in the actual line, the atress condition is comparatively complicated in whole banded way bed body for the railway bed sample cell cube, when receiving train load effect, the railway bed sample cell cube not only receives vertical effort, still receives the initiative pressure that cell cube side direction rubble ballast produced to the cell cube side because gravity and loading effect's extrusion deformation simultaneously, and this partial pressure has the inhomogeneity in cell cube side distribution, mainly embodies the lateral pressure variation in that different height received. Therefore, the second type of railway ballast model box cannot simulate the regional difference of the pressure applied to the side surface of the railway bed sample unit, and cannot fully and truly reduce the actual stress condition of the railway bed under the action of train load, so that the mechanical property change, the accumulated settlement rule and the particle crushing condition of the railway bed under the action of cyclic load cannot be accurately reflected.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problems and provides a confining pressure loading test device suitable for a fatigue test.
In order to solve the technical problems, the technical scheme provided by the utility model is as follows:
a confining pressure loading test device suitable for fatigue test comprises a railway ballast test model box and a confining pressure control system, wherein the railway ballast test model box comprises a bottom plate and detachable side plates with the same four surfaces, the detachable side plates are assembled by bolts, a detachable first baffle plate is arranged in the railway ballast test model box relatively, detachable triangular supports are arranged on the four surfaces of the outer side of the railway ballast test model box, a beam connected by bolts is arranged at the upper ends of the two triangular supports, the confining pressure control system comprises an envelope body arranged between the first baffle plate and the side plates, the envelope body comprises a first water chamber, a second water chamber is uniformly arranged on one side of the first water chamber, a protective layer is arranged on the other side of the second water chamber, a pressure sensor is arranged between the protective layer and the second water chamber, a second baffle plate containing a permeable hole is uniformly arranged in the first water chamber, the outside of second grade hydroecium be equipped with inlet tube one, the outside of one-level hydroecium be equipped with inlet tube two, the experimental mold box of railway ballast inside be equipped with and support second grade hydroecium and detachable backup pad, the backup pad be located between two second grade hydroeciums, the experimental mold box of railway ballast in be equipped with the lithotripsy of multilayer railway ballast grading, two-layer the lithotripsy of railway ballast grading between be equipped with the soil pressure cell, it is multi-storied the lithotripsy top of railway ballast grading be equipped with prefabricated sleeper section, prefabricated sleeper section upper end be equipped with prefabricated rail section, prefabricated rail section pass through the rail fastener and connect prefabricated sleeper section.
After adopting the structure, the utility model has the following advantages:
1: the device can be used for measuring the mechanical property change of the ballast bed after the cyclic load action under the conditions of different lateral confining pressures and vertical load actions in a laboratory, accumulating the sedimentation rule and the particle crushing condition, and controlling the pressure in the bag body, and can meet the change conditions of the mechanical property, the sedimentation displacement and the particle grading of a railway ballast bed sample after the cyclic load action of certain amplitude and frequency under various working conditions of different particle grading compositions, different dirty materials and contents, different water content degrees, different ballast residues of the ballast bed, geogrids and the like under the conditions of different confining pressures.
2: the railway ballast test model box is assembled by a bottom plate and detachable side plate bolts with the same four surfaces, and can be used for easily changing samples and cleaning the box body;
3: the first water inlet pipe and the second water inlet pipe can respectively convey water to the second-stage water chamber and the first-stage water chamber, active lateral pressure of ballast graded broken stones can be given from different directions in a layering mode, lateral constraint and horizontal deformation of a ballast bed can be simulated really, and the defects of a conventional rigid lateral wall test box are overcome.
As an improvement, the outer sides of the first water inlet pipe and the second water inlet pipe are both provided with switch valves.
As an improvement, the side plate is provided with a mounting hole matched with the support plate for use, and the side plate is provided with a communication hole matched with the first water inlet pipe for use.
As an improvement, the soil pressure cell is located under the prefabricated sleeper section, and the upper end of the triangular support frame is provided with a settlement displacement sensor, and a probe of the settlement displacement sensor is in contact with the upper surface of the prefabricated sleeper section.
As an improvement, the cross beam is uniformly provided with adjusting threaded holes.
As an improvement, the other end of the water inlet pipe II is provided with a fixed water source container, and the other end of the fixed water source container is connected with an air pump.
As an improvement, the surface of the secondary water chamber is provided with a PVC flexible plate which is used as a protective layer of the surface of the secondary water chamber to play a role in protection.
As an improvement, a rubber pad is laid below the graded broken stone ballast bottom layer.
Drawings
Fig. 1 is a front view of the present invention.
FIG. 2 is a schematic view of the internal structure of the railway ballast test model box.
Fig. 3 is a top view of the railway ballast test model box of the utility model.
Figure 4 is a schematic view of the structure of the capsule of the present invention.
FIG. 5 is a stress analysis diagram of a sample in the railway ballast cyclic load fatigue test process.
Fig. 6 is a schematic view of an assembly structure of a ballast test model box according to an embodiment of the utility model.
Fig. 7 is a schematic assembly structure diagram of a second ballast test model box according to an embodiment of the utility model.
As shown in the figure: 1. a railway ballast test model box; 1.1, a bottom plate; 1.2, side plates; 1.3, a first clapboard; 2. a confining pressure control system; 2.1, a capsule body; 2.11, a primary water chamber; 2.12, a secondary water chamber; 2.13, a pressure sensor; 2.14, a second clapboard; 2.2, a first water inlet pipe; 2.3, a water inlet pipe II; 3. a reaction frame upright post; 3.1, a reaction frame beam; 3.2, an oil pressure servo loading device; 4. a fatigue testing machine; 4.1, an excitation head; 4.2, prefabricating a sleeper section; 4.3, a settlement displacement sensor; 5. a triangular support frame; 5.1, a cross beam; 6. a support plate; 7. a soil pressure cell; 8. mounting holes; 9. a communicating hole; 10. and adjusting the threaded hole.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
With reference to the attached drawings 1-4, a confining pressure loading test device suitable for fatigue tests comprises a railway ballast test model box 1 and a confining pressure control system 2, wherein the railway ballast test model box 1 comprises a bottom plate 1.1 and a detachable side plate 1.2 with the same four surfaces, the railway ballast test model box 1 is internally provided with a detachable partition plate 1.3, the four surfaces of the outer side of the railway ballast test model box 1 are respectively provided with a detachable triangular support frame 5, the upper ends of the two triangular support frames 5 are provided with a cross beam 5.1 connected by bolts, the confining pressure control system 2 comprises an airbag body 2.1 arranged between the partition plate 1.3 and the side plate 1.2, the airbag body 2.1 comprises a primary water chamber 2.11, one side of the primary water chamber 2.11 is uniformly provided with a secondary water chamber 2.12, the other side of the secondary water chamber 2.12 is provided with a protective layer, a pressure sensor 2.13 is arranged between the protective layer and the secondary water chamber 2.12, one-level hydroecium 2.11 in even be equipped with contain the baffle two 2.14 of the hole of permeating water, the outside of second grade hydroecium 2.12 be equipped with inlet tube one 2.2, the outside of one-level hydroecium 2.11 be equipped with inlet tube two 2.3, the experimental model case 1 of railway ballast inside be equipped with and support second grade hydroecium 2.12 and detachable backup pad 6, backup pad 6 be located between two second grade hydroecium 2.12, the experimental model case of railway ballast 1 in be equipped with the lithotripsy of multilayer railway ballast grading, two-layer the railway ballast grading rubble between be equipped with soil pressure cell 7, the multilayer railway ballast grading top be equipped with prefabricated sleeper section 4.2, prefabricated sleeper section 4.2 upper end be equipped with prefabricated steel rail section, prefabricated steel rail section pass through the rail fastener and connect prefabricated sleeper section 4.2.
And the outer sides of the first water inlet pipe 2.2 and the second water inlet pipe 2.3 are both provided with switch valves.
The side plate 1.2 is provided with a mounting hole 8 matched with the support plate 6 for use, and the side plate 1.2 is provided with a communication hole 9 matched with the water inlet pipe I2.2 for use.
The soil pressure cell be located prefabricated sleeper section 4.2 under, 5 upper ends of triangular supports frame be equipped with settlement displacement sensor 4.3 and settlement displacement sensor 4.3's probe and prefabricated sleeper section 4.2 upper surface contact. When the utility model is implemented specifically, the upper end of the triangular support frame 5 is provided with a connecting plate, and the connecting plate, the triangular support frame 5 and the cross beam 5.1 are fixed together by fixing bolts.
When the utility model is implemented specifically, the number of the first partition boards 1.3 is four, each first partition board 1.3 is fixedly connected with the side plate 1.2 through bolts, and the four first partition boards 1.3 and the side plate 1.2 form a structure shaped like a Chinese character 'hui'.
The middle of the cross beam 5.1 is uniformly provided with adjusting threaded holes 10.
In specific implementation, the utility model further comprises a fatigue testing machine 4 (the prior art) as a device for providing vertical cyclic load in a test, wherein the fatigue testing machine 4 comprises a reaction frame upright post 3, a reaction frame cross beam 3.1, an oil pressure servo loading device 3.2 and an excitation head 4.1. The railway ballast test model box 1 of the utility model meets two assembling modes,
the first embodiment is as follows:
firstly, as shown in fig. 6, a first partition plate 1.3 and a confining pressure control system 2 are arranged in a railway ballast test model box 1, and in order to simulate lateral confining pressure supply, a railway bed sample cyclic load fatigue test can be carried out under the condition of lateral active confining pressure;
example two:
the second concatenation mode is as shown in fig. 7, dismantle two curb plates 1.2 and confined pressure control system 2, let triangular supports 5 near baffle 1.3, can guarantee that the unchangeable while in inside space gets rid of confined pressure control system 2, but the condition of side limit is nevertheless had in order to simulate no side direction confined pressure, thereby can study the mechanical properties change when the ballast bed receives cyclic load effect under the rigidity side limit, accumulative settlement law and the broken condition of granule, simultaneously can be through adjusting threaded hole 10, realize the switching of two kinds of concatenation modes.
The other end of the water inlet pipe II 2.3 is provided with a fixed water source container, and the other end of the fixed water source container is connected with an air pump.
The surface of the secondary water chamber 2.12 is provided with a PVC flexible board which is used as a protective layer of the surface of the secondary water chamber to play a role in protection.
When the ballast testing device is specifically implemented, a sliding groove matched with the first partition plate 1.3 is formed in the bottom plate on the inner side of the ballast testing model box 1.
The working principle of the utility model is as follows: firstly, a railway ballast test model box is assembled, a first partition plate is placed into a sliding groove, a bag body is placed between a first partition plate and a side plate, a first water inlet pipe and a second water inlet pipe penetrate out of the railway ballast test model box through a communicating hole to be connected with the outside, the other end of the first water inlet pipe is provided with a fixed water source container, the other end of the fixed water source container is connected with an air pump, one end of the second water inlet pipe is connected with an external normal-pressure water source, the air pump is used for inflating and pressurizing one fixed water source container, and the water pressure of the fixed water source container is pressed into a second-stage water chamber to achieve the high-pressure effect.
And (3) filling pre-configured ballast graded crushed stones into a sample filling and distinguishing layer in the ballast test model box, dividing the sample into three layers, placing a soil pressure box at the bottom before filling the sample, compacting the sample to the degree of compaction required by the test after filling the sample layer, placing a soil pressure box on the upper surface of the first layer, and filling a second layer of sample. After the second layer is filled and compacted, a soil pressure cell is placed on the surface of the second layer, in the process of filling the last layer of sample, a prefabricated sleeper section is properly embedded into the sample by a certain depth, the contact level of a sleeper surface and the sample surface is ensured, the center of the sleeper is positioned right above the soil pressure cell, a prefabricated steel rail is fixed on the sleeper through a fastener, finally, a settlement displacement sensor is fixed on the upper end of a triangular support frame, a measuring point probe of the settlement displacement sensor is in contact with the upper surface of the prefabricated sleeper section, and water is filled into a primary water chamber from two directions through a water inlet pipe.
When the water sac just occupies the gap between the first partition plate and the side plate, stopping filling water into the first-stage water chamber, manually disassembling the first partition plate, splicing the triangular support frame and the cross beam together and anchoring the triangular support frame and the cross beam on the bottom plate and the side plate, simultaneously inserting the support plate into the mounting hole to support the second-stage water chamber, opening a switch and an air pump of a water inlet pipe corresponding to the first second-stage water chamber, pressurizing the water in the container into the second-stage water chamber, filling water into the second-stage water chamber through the water inlet pipe and pressurizing the second-stage water chamber, stopping when the numerical value of the pressure sensor reaches the confining pressure required by the test scheme, sequentially operating to gradually complete the water filling and pressurizing operation of each second-stage water chamber, determining the confining pressure required by the test before filling water into the second-stage water chamber and pressurizing, generally selecting different confining pressure states according to different types of track beds, simplifying the ballast bed box model into a unit body, stressing in multiple directions, acting on the load by the circulating load of a press machine in the vertical direction, and generating settlement displacement in the direction; the horizontal direction is divided into three layers which respectively represent the lateral pressure independently provided by the three secondary water chambers of one water bag, as shown in fig. 5, the unit body is divided into three layers, the two sides of the unit body are respectively subjected to P (1), P (2), P (3), P (4), P (5) and P (6), the pressure in each direction is provided by the independent secondary water chambers, and the pressure in each direction is not fixedly related to the pressure in each other. Finally, the required confining pressure in each direction can be determined one by one according to actual working conditions.
And starting a fatigue testing machine, adding a 10kN vertical load to stabilize the contact between the prefabricated sleeper section and the graded railway ballast and ensure the railway ballast sample to be fully compacted before applying the cyclic load, taking the numerical values of the soil pressure box and the pressure sensor as initial references, adjusting the mode into a cyclic load loading mode, and sequentially setting the cyclic loading frequency, the maximum loading pressure and the minimum loading pressure according to the requirements of the scheme. And collecting data collected by the soil pressure cell and the settlement displacement sensor, facilitating subsequent analysis, obtaining the particle composition change of the sample under the action of the cyclic load through a screening test, and performing comparison analysis. The mechanical property change, the accumulated sedimentation rule and the particle crushing condition of the group of samples before and after the test can be obtained, the test data is collated, the data is analyzed and relevant reports are made
The present invention and its embodiments have been described above, and the description is not intended to be limiting, and the drawings are only one embodiment of the present invention, and the actual structure is not limited thereto. In summary, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the utility model as defined by the appended claims.
Claims (7)
1. A confining pressure loading test device suitable for fatigue tests comprises a railway ballast test model box (1) and a confining pressure control system (2), and is characterized in that the railway ballast test model box (1) comprises a bottom plate (1.1) and detachable side plates (1.2) with the same four surfaces, the railway ballast test model box (1) is internally provided with a detachable partition plate I (1.3), the four surfaces of the outer side of the railway ballast test model box (1) are respectively provided with a detachable triangular support frame (5), the upper ends of the two triangular support frames (5) are respectively provided with a beam (5.1) connected by bolts, the confining pressure control system (2) comprises an airbag body (2.1) arranged between the partition plate I (1.3) and the side plates (1.2), the airbag body (2.1) comprises a primary water chamber (2.11), one side of the primary water chamber (2.11) is uniformly provided with a secondary water chamber (2.12), the opposite side of second grade hydroecium (2.12) be equipped with the protective layer, protective layer and second grade hydroecium (2.12) between be equipped with pressure sensor (2.13), first grade hydroecium (2.11) in even be equipped with contain the baffle two (2.14) of the hole of permeating water, the outside of second grade hydroecium (2.12) be equipped with inlet tube one (2.2), the outside of first grade hydroecium (2.11) be equipped with inlet tube two (2.3), the inside of railway ballast test model case (1) be equipped with support second grade hydroecium (2.12) and detachable backup pad (6), backup pad (6) be located between two second grade hydroecium (2.12), railway ballast test model case (1) in be equipped with the multistage broken stone of railway ballast grading, two-layer railway ballast grading is equipped with soil pressure cell (7) between the broken stone, the multilayer railway ballast grading top be equipped with prefabricated sleeper section (4.2), prefabricated sleeper section (4.2) upper end be equipped with prefabricated rail section, prefabricated rail section pass through rail fastener and connect prefabricated sleeper section (4.2).
2. The confining pressure loading test device suitable for fatigue test according to claim 1, characterized in that: and the outer sides of the first water inlet pipe (2.2) and the second water inlet pipe (2.3) are both provided with switch valves.
3. The confining pressure loading test device suitable for fatigue test according to claim 1, characterized in that: the side plate (1.2) is provided with a mounting hole (8) used for being matched with the support plate (6), and the side plate (1.2) is provided with a communication hole (9) used for being matched with the first water inlet pipe (2.2).
4. The confining pressure loading test device suitable for fatigue test according to claim 1, characterized in that: the soil pressure cell be located prefabricated sleeper section (4.2) under, the upper end of triangular supports frame (5) be equipped with settlement displacement sensor (4.3) and subside displacement sensor (4.3) probe and prefabricated sleeper section (4.2) upper surface contact.
5. The confining pressure loading test device suitable for fatigue test according to claim 1, characterized in that: the middle of the cross beam (5.1) is uniformly provided with adjusting threaded holes (10).
6. The confining pressure loading test device suitable for the fatigue test according to claim 2, characterized in that: the other end of the second water inlet pipe (2.3) is provided with a fixed water source container, and the other end of the fixed water source container is connected with an air pump.
7. The confining pressure loading test device suitable for fatigue test according to claim 1, characterized in that: and a PVC flexible plate is arranged on the surface of the secondary water chamber (2.12).
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| Application Number | Priority Date | Filing Date | Title |
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| CN202122797603.7U CN216525270U (en) | 2021-11-16 | 2021-11-16 | Confining pressure loading test device suitable for fatigue test |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202122797603.7U CN216525270U (en) | 2021-11-16 | 2021-11-16 | Confining pressure loading test device suitable for fatigue test |
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| CN216525270U true CN216525270U (en) | 2022-05-13 |
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