Vertical graded loading test mechanism for friction pile foundation in centrifugal field

Abstract

The utility model belongs to the technical field of geotechnical centrifugal model test devices, and particularly relates to a vertical graded loading test mechanism for a friction pile foundation in a centrifugal field, which comprises a centrifugal model box, a simulated soil body is arranged in the centrifugal model box, a simulated pile foundation is embedded in the simulated soil body, and the simulated pile foundation is arranged in the centrifugal model box. A traction device and a tension compensation device are arranged above the simulation pile foundation. According to the vertical graded loading test mechanism for the friction pile foundation in the centrifugal field, through the application of a tension compensation device, in the rotating process of a centrifugal model box, the telescopic end of an electric telescopic rod stretches out and draws back to drive a hinged pull rod to move, then a wear-resisting piece is driven to make contact with a simulation pile foundation, and the simulation pile foundation is extruded; when the traction device pulls the simulation pile foundation in the rotation process of the centrifugal model box, the influence of the gravity of the simulation pile foundation on an experiment is reduced through the sliding friction force of the wear-resisting piece and the simulation pile foundation, and the accuracy of a test result is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical centrifugal model test devices, in particular to a vertical graded loading test mechanism for a friction pile foundation in a centrifugal field. Background Art

[0002] The centrifuge exerts super gravity through high-speed rotation to achieve the "time and space compression" effect, which can reduce the large-scale pile foundation in actual engineering to the indoor test size level and greatly shorten the test cycle. When studying the bearing capacity of friction pile foundations, it is necessary to apply vertical loads to the friction pile foundations in stages.

[0003] At present, in the prior art, for example, a Chinese patent with a publication number of CN217231973U discloses a vertical graded loading test device for friction pile foundations in a centrifugal field. The device contains the bearing soil and the friction pile foundations through a centrifugal model box, and vertically loads multiple loading units onto the friction pile foundations as required through a loading assembly, thereby improving the vertical loading stability and reliability to a certain extent and reducing safety hazards through a simple structure. However, in actual use, due to the effect of centrifugal force, when the traction mechanism is loading the friction pile foundation, the friction pile foundation is subjected to the load test. During pulling, the centrifugal model box is rotating. When the friction pile foundation rotates to the bottom, the pulling force applied to the traction mechanism is the centripetal force of the friction pile foundation and the loading assembly plus the gravity of the friction pile foundation and the loading assembly. When the friction pile foundation rotates to the top, the pulling force applied to the traction mechanism is the centripetal force of the friction pile foundation and the loading assembly minus the gravity of the friction pile foundation and the loading assembly, which has a great influence on the force applied to the traction mechanism and thus affects the test. In view of this, we propose a vertical graded loading test mechanism for friction pile foundations in a centrifugal field. Utility Model Content

[0004] The main purpose of the utility model is to provide a vertical graded loading test mechanism for a friction pile foundation in a centrifugal field, which can solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the utility model proposes a vertical graded loading test mechanism for a friction pile foundation in a centrifugal field, comprising a centrifugal model box, wherein a simulated soil body is arranged in the centrifugal model box, wherein a simulated pile foundation is embedded and installed in the simulated soil body, and a traction device and a tension compensation device are arranged above the simulated pile foundation, wherein the tension compensation device comprises:

[0006] A fixed plate, the fixed plate is fixedly connected to the inner wall of the centrifugal model box, and an electric telescopic rod is fixedly connected to the upper side of the fixed plate;

[0007] An articulated pull rod, the articulated pull rod is articulated on the telescopic end of the electric telescopic rod, and one end of the articulated pull rod away from the electric telescopic rod is articulated with a connecting rod;

[0008] and a booster assembly, wherein the booster assembly is fixedly connected to the end of the connecting rod.

[0009] Preferably, one end of the connecting rod away from the boost assembly is fixedly connected to a guide block, the guide block is penetrated by the guide rod and is slidably connected to the guide rod, and both ends of the guide rod are fixedly connected to fixed blocks. Through the use of the guide rod, the guide block can be more stable when sliding.

[0010] Preferably, the fixing block is fixedly connected to the upper side of the fixing plate, and the guide block is slidably connected to the upper side of the fixing plate.

[0011] Preferably, the boost assembly includes an arc-shaped plate, the arc-shaped plate is detachably connected to a ladder block, a wear-resistant plate is fixedly connected to the outer wall of the ladder block, a fixing rod is fixedly connected to the outer wall of the arc-shaped plate, the fixing rod passes through the limit block, and the fixing rod and the limit block are elastically connected by a torsion spring.

[0012] Preferably, a trapezoidal groove is provided on one side of the arc plate close to the trapezoidal block, and the size of the trapezoidal block matches that of the trapezoidal groove. By using the trapezoidal groove and the trapezoidal block, the trapezoidal block can be limited when inserted into the trapezoidal groove.

[0013] Preferably, the traction device includes a stepper motor, a winding roller is fixedly connected to the output end of the stepper motor, a steel rope is wound around the winding roller, one end of the steel rope away from the winding roller is fixedly connected to the top of the simulated pile foundation, and the steel rope passes through the loading assembly.

[0014] The utility model provides a vertical graded loading test mechanism for friction pile foundation in a centrifugal field, which has the following beneficial effects:

[0015] (1) The vertical graded loading test mechanism for the friction pile foundation in the centrifugal field uses the practical use of the tension compensation device, so that during the rotation of the centrifugal model box, the telescopic end of the electric telescopic rod is extended and retracted, driving the hinged pull rod to move, thereby driving the wear-resistant sheet to contact with the simulated pile foundation and squeeze the simulated pile foundation, so that when the traction device pulls the simulated pile foundation during the rotation of the centrifugal model box, the friction force of the sliding between the wear-resistant sheet and the simulated pile foundation is reduced, thereby improving the accuracy of the test results.

[0016] (2) The vertical graded loading test mechanism for the friction pile foundation in the centrifugal field uses a booster assembly so that after a long period of use, the wear-resistant sheet can be removed by rotating the limit block to release the limit on the ladder block, and then the wear-resistant sheet can be replaced, thereby ensuring the subsequent continuous use of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the overall three-dimensional internal structure of the utility model;

[0019] Figure 2 It is a schematic diagram of a partial three-dimensional structure of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the tension compensation device of the utility model;

[0021] Figure 4 For this utility model Figure 3 Schematic diagram of the structure of A;

[0022] Figure 5 This is a schematic diagram of the structure of the booster assembly of the utility model.

[0023] Description of Figure Numbers:

[0024] 1. Centrifugal model box; 2. Simulated soil; 3. Simulated pile foundation; 4. Traction device; 5. Tension compensation device; 41. Stepper motor; 42. Winding roller; 43. Steel rope; 44. Loading assembly; 51. Fixed plate; 52. Electric telescopic rod; 53. Articulated pull rod; 54. Connecting rod; 55. Pressurization assembly; 56. Guide block; 57. Guide rod; 58. Fixed block; 551. Arc plate; 552. Trapezoidal block; 553. Wear-resistant sheet; 554. Fixed rod; 555. Limit block; 5511. Trapezoidal groove.

[0025] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] See also Figure 1-Figure 5The utility model proposes a vertical graded loading test mechanism for a friction pile foundation in a centrifugal field, comprising a centrifugal model box 1, a simulated soil body 2 is arranged in the centrifugal model box 1, a simulated pile foundation 3 is embedded and installed in the simulated soil body 2, a traction device 4 and a tension compensation device 5 are arranged above the simulated pile foundation 3, the traction device 4 comprises a stepper motor 41, a winding roller 42 is fixedly connected to the output end of the stepper motor 41, a steel rope 43 is wound on the winding roller 42, one end of the steel rope 43 away from the winding roller 42 is fixedly connected to the top of the simulated pile foundation 3, the steel rope 43 passes through the loading component 44, and the use of the stepper motor 41 can drive the winding roller 42 to rotate, so that the steel rope 43 can pull the loading component 44 and the simulated pile foundation 3. The traction device 4 of the utility model is consistent with the traction mechanism in patent announcement number CN217231973U, which is a disclosed prior art and will not be described in detail here.

[0028] In the embodiment of the utility model, in order to improve the accuracy of the device during testing, specifically, the tension compensation device 5 includes a fixed plate 51, the fixed plate 51 is fixedly connected to the inner wall of the centrifugal model box 1, the upper side of the fixed plate 51 is fixedly connected to an electric telescopic rod 52, the telescopic end of the electric telescopic rod 52 is hinged with a hinged pull rod 53, the end of the hinged pull rod 53 away from the electric telescopic rod 52 is hinged with a connecting rod 54, the end of the connecting rod 54 is fixedly connected to a booster assembly 55, the end of the connecting rod 54 away from the booster assembly 55 is fixedly connected to a guide block 56, the guide block 56 is penetrated by a guide rod 57 and is slidably connected to the guide rod 57, by using the guide rod 57, the guide block 56 is limited when moving, to ensure the stability of the movement of the guide block 56, and the two ends of the guide rod 57 are fixedly connected There is a fixed block 58, which is fixedly connected to the upper side of the fixed plate 51, and a guide block 56 is slidably connected to the upper side of the fixed plate 51. By starting the electric telescopic rod 52, when the electric telescopic rod 52 is extended or retracted, it can drive the hinged pull rod 53 to move, and then pull the connecting rod 54 to move, so that the guide block 56 can slide stably under the limiting action of the guide rod 57, so that the booster component 55 can approach the simulated pile foundation 3 and squeeze the simulated pile foundation 3. When the magnitude of the squeezing force of the simulated pile foundation 3 by the booster component 55 is different, the friction force of the simulated pile foundation 3 sliding is also different, so that when the traction device 4 pulls the simulated pile foundation 3 during the rotation of the centrifugal model box 1, the effect of the gravity of the simulated pile foundation 3 on the experiment is reduced through the action of the friction force, thereby improving the accuracy of the test results.

[0029] It should be noted that during the rotation of the centrifugal model box 1, when the simulated pile foundation 3 rotates to the bottom, the pulling force exerted on the traction mechanism 4 is the centripetal force of the simulated pile foundation 3 and the loading assembly 44 plus the gravity of the simulated pile foundation 3 and the loading assembly 44. At this time, the booster assembly 55 does not contact the simulated pile foundation 3, so that the simulated pile foundation 3 will not be affected by the friction force when moving. During the rotation of the simulated pile foundation 3 to the top, the pulling force exerted on the traction mechanism 4 will gradually decrease. At this time, under the action of the electric telescopic rod 52, the booster assembly 55 gradually squeezes the simulated pile foundation 3, so that the simulated pile foundation 3 is affected by the friction force when being pulled. The magnitude of the friction force increases with the increase of the pressure of the booster assembly 55 on the simulated pile foundation 3, specifically f=F*u, u is the friction factor, and F is the pressure magnitude. When the simulated pile foundation 3 rotates to the top, the friction force is the largest, which is used to reduce the influence of the gravity of the simulated pile foundation 3 and the loading assembly 44 on the test.

[0030] Furthermore, in order to ensure the sustainable use of the booster assembly 55, specifically, the booster assembly 55 includes an arc plate 551, which is detachably connected to a trapezoidal block 552, and a trapezoidal groove 5511 is provided on one side of the arc plate 551 close to the trapezoidal block 552, and the size of the trapezoidal block 552 matches that of the trapezoidal groove 5511, a wear-resistant sheet 553 is fixedly connected to the outer wall of the trapezoidal block 552, and a fixing rod 554 is fixedly connected to the outer wall of the arc plate 551, the fixing rod 554 passes through the limit block 555, and the fixing rod 554 is elastically connected to the limit block 555 by a torsion spring, and after long-term use, the wear-resistant sheet 553 can be released from the limit of the trapezoidal block 552 by rotating the limit block 555, so that the wear-resistant sheet 553 can be taken out, and then the wear-resistant sheet 553 can be replaced, thereby ensuring the subsequent continuous use of the device.

[0031] During use, during the rotation of the centrifugal model box 1, when the simulated pile foundation 3 rotates to the bottom, the booster assembly 55 does not contact the simulated pile foundation 3, and during the rotation of the simulated pile foundation 3 to the top, the pulling force on the traction mechanism 4 will gradually decrease. At this time, the electric telescopic rod 52 is started, and the electric telescopic rod 52 contracts, driving the articulated pull rod 53 to move, and then pulling the connecting rod 54 to move, so that the guide block 56 slides stably under the limiting action of the guide rod 57, and then the wear-resistant plate 553 approaches the simulated pile foundation 3, and the wear-resistant plate 553 gradually squeezes the simulated pile foundation 3, so that the simulated pile foundation 3 is subjected to friction when being pulled, and the magnitude of the friction increases with the increase of the pressure of the booster assembly 55 on the simulated pile foundation 3, thereby reducing the influence of the gravity of the simulated pile foundation 3 and the loading assembly 44 on the test.

[0032] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A vertical graded loading test mechanism for a friction pile foundation in a centrifugal field, comprising a centrifugal model box (1), characterized in that: The centrifugal model box (1) is provided with a simulated soil body (2), a simulated pile foundation (3) is embedded and installed in the simulated soil body (2), a traction device (4) and a tension compensation device (5) are provided above the simulated pile foundation (3), and the tension compensation device (5) comprises: A fixed plate (51), the fixed plate (51) being fixedly connected to the inner wall of the centrifugal model box (1), and an electric telescopic rod (52) being fixedly connected to the upper side of the fixed plate (51); An articulated pull rod (53), wherein the articulated pull rod (53) is articulated on the telescopic end of the electric telescopic rod (52), and a connecting rod (54) is articulated on one end of the articulated pull rod (53) away from the electric telescopic rod (52); and a booster assembly (55), wherein the booster assembly (55) is fixedly connected to the end of the connecting rod (54).

2. A vertical graded loading test mechanism for friction pile foundation in a centrifugal field according to claim 1, characterized in that: One end of the connecting rod (54) away from the supercharging assembly (55) is fixedly connected to a guide block (56), the guide block (56) is penetrated by a guide rod (57) and is slidably connected to the guide rod (57), and both ends of the guide rod (57) are fixedly connected to fixed blocks (58).

3. A vertical graded loading test mechanism for friction pile foundation in a centrifugal field according to claim 2, characterized in that: The fixing block (58) is fixedly connected to the upper side of the fixing plate (51), and the guide block (56) is slidably connected to the upper side of the fixing plate (51).

4. A vertical graded loading test mechanism for friction pile foundation in a centrifugal field according to claim 1, characterized in that: The booster assembly (55) comprises an arc-shaped plate (551), the arc-shaped plate (551) is detachably connected to a ladder block (552), a wear-resistant sheet (553) is fixedly connected to the outer wall of the ladder block (552), a fixing rod (554) is fixedly connected to the outer wall of the arc-shaped plate (551), the fixing rod (554) passes through the limit block (555), and the fixing rod (554) and the limit block (555) are elastically connected via a torsion spring.

5. A vertical graded loading test mechanism for friction pile foundation in a centrifugal field according to claim 4, characterized in that: A trapezoidal groove (5511) is provided on one side of the arc-shaped plate (551) close to the trapezoidal block (552), and the sizes of the trapezoidal block (552) and the trapezoidal groove (5511) match each other.

6. A vertical graded loading test mechanism for friction pile foundation in a centrifugal field according to claim 1, characterized in that: The traction device (4) comprises a stepper motor (41), the output end of the stepper motor (41) is fixedly connected to a winding roller (42), a steel rope (43) is wound around the winding roller (42), one end of the steel rope (43) away from the winding roller (42) is fixedly connected to the top of the simulated pile foundation (3), and the steel rope (43) passes through the loading assembly (44).

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