A flexural test bench for prestressed concrete sheet piles

Abstract

The invention relates to the technical field of concrete sheet pile bending test, and specifically to a prestressed concrete sheet pile bending test pedestal, comprising vertical beams, which are a pair of vertical beams and are symmetrically arranged, wherein the upper ends of the pair of vertical beams are fixedly connected to an upper cross beam, the lower ends of the pair of vertical beams are fixedly connected to a lower cross beam, a pair of bearing frames are fixedly connected to the lower cross beam, a fixing assembly for carrying concrete piles of different shapes is provided on the bearing frame, a locking assembly for locking the fixing assembly is provided above the fixing assembly, and a loading assembly for applying pressure to the concrete pile is provided on the upper cross beam. The invention can improve friction by contacting the rubber strip with the surface of the concrete pile, has an anti-slip effect, and improves stability during loading, and at the same time, a spring rod, a first elastic metal strip, and a second elastic metal strip can cooperate to fit on the surface of a square or round concrete pile and apply pressure to it, so that the concrete pile is evenly stressed, thereby improving the accuracy of the bending test.

Description

Technical Field

[0001] The present invention relates to the technical field of flexural tests of concrete sheet piles, and specifically to a flexural test bench for prestressed concrete sheet piles. Background Art

[0002] The flexural test of prestressed concrete sheet piles is to vertically load a sample through a loading device, observe and record its deformation and failure process, and obtain relevant data. Finally, the obtained data is statistically analyzed to evaluate its flexural performance.

[0003] The traditional flexural test of prestressed concrete sheet piles is to directly vertically load the sheet pile through devices such as jacks, observe and record its deformation and failure process, and obtain relevant data. However, this vertical loading has uneven stress, which affects the test results. For example, the component in contact with the end of the jack and the sheet pile is of a fixed size. If it squeezes a sheet pile wider than itself, the force on the sheet pile will be concentrated, causing the sheet pile to be damaged faster and not achieving the best test data. At the same time, when vertically loading square piles and circular piles, it is necessary to frequently replace the load distribution beam that can match the shape of the concrete pile, and the operation is extremely inconvenient.

[0004] In view of this, the present invention proposes a flexural test bench for prestressed concrete sheet piles, which solves the above technical problems. Summary of the Invention

[0005] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0006] A flexural test bench for prestressed concrete sheet piles includes vertical beams. There are a pair of vertical beams which are symmetrically arranged. The upper ends of the pair of vertical beams are fixedly connected with an upper cross beam, and the lower ends of the pair of vertical beams are fixedly connected with a lower cross beam. The pair of vertical beams, the upper cross beam, and the lower cross beam form a rectangular frame. A pair of bearing frames are fixedly connected to the lower cross beam. A fixing component for bearing concrete piles of different shapes is provided on the bearing frame. A locking component for locking the fixing component is provided above the fixing component. A loading component for applying pressure to the concrete pile is provided on the upper cross beam. The loading component includes a load distribution beam. A plurality of spring rods are fixedly connected to the lower end surface of the load distribution beam. A first elastic metal strip is provided below the spring rods, and the lower ends of the plurality of spring rods are connected in series by the first elastic metal strip.

[0007] As a preferred embodiment of the present invention, the fixing component includes a bearing block. There are a pair of bearing blocks which are symmetrically arranged. Calibration holes are formed on the adjacent surfaces of the pair of bearing blocks. A central column is fixedly connected in the calibration hole of one of the bearing blocks. The central column abuts against the bottom of the calibration hole in the other bearing block. A return spring is nested on the central column. The two ends of the return spring are respectively fixedly connected in the two calibration holes of the symmetric bearing blocks.

[0008] As a preferred embodiment of the present invention, a slider is fixedly connected to the lower end surface of the bearing block. A chute is provided below the bearing block. The chute is formed on the upper end surface of the bearing frame. The slider is slidably connected in the chute.

[0009] As a preferred embodiment of the present invention, the upper end surface of the bearing block is concave for fitting with the concrete pile. A rubber layer is provided on the concave surface of the bearing block.

[0010] As a preferred embodiment of the present invention, the locking component is fixedly connected to the lower end surface of the upper cross beam. The locking component includes a jack. The jack is fixedly connected to the lower end surface of the upper cross beam. The output end of the jack is fixedly connected to a cross bar. A push-pull rod is fixedly connected to the lower end surface of the cross bar. A first gas collecting pipe is provided below the push-pull rod. The first gas collecting pipe is fixedly connected to the inner wall of the vertical beam. The lower end of the push-pull rod extends into the interior of the first gas collecting pipe and is fixedly connected to a first piston. The first piston is slidably connected inside the first gas collecting pipe. A guide pipe is fixedly connected to the bottom of the first gas collecting pipe. A suction hole is fixedly connected to one side of the bottom of the first gas collecting pipe. A one-way valve is provided in the suction hole. This one-way valve can only allow gas to enter and not exit.

[0011] As a preferred embodiment of the present invention, a second gas collecting pipe is fixedly connected to one side of the bearing block. One end of the guide pipe is fixedly connected to the upper end of the second gas collecting pipe. A second piston is slidably connected inside the second gas collecting pipe. A pressure valve is fixedly connected to one side of the upper end portion of the second gas collecting pipe. The height of the pressure valve is always higher than the height of the second piston. A pressure rod is fixedly connected to the lower end of the second piston. The lower end of the pressure rod extends out of the second gas collecting pipe and is fixedly connected to a pressing plate.

[0012] As a preferred embodiment of the present invention, the pressing plate is slidably connected to one side of the bearing block. A locking head is provided below the pressing plate. The locking head is movably connected to one side of the bearing block by a torsion spring. A fixing block is provided on one side of the locking head. The fixing block is fixedly connected to the upper end surface of the bearing frame. A plurality of limiting columns are fixedly connected to the side surface of the fixing block. The locking head cooperates with the limiting columns.

[0013] As a preferred solution of the present invention, the lower end face of the spring rod is fixedly connected with a T-shaped bolt, the No. 1 elastic metal strip is movably connected to the spring rod through the T-shaped bolt, a support spring is nested around the T-shaped bolt, the upper end of the support spring is fixedly connected to the No. 1 elastic metal strip, and the lower end of the support spring is fixedly connected to the No. 2 elastic metal strip.

[0014] As a preferred solution of the present invention, a rubber strip is fixedly connected to the lower end surface of the second elastic metal strip.

[0015] Beneficial effects of the present invention:

[0016] The present invention can improve friction through the contact between the rubber strip and the surface of the concrete pile, has an anti-skid effect, and improves the stability during loading. At the same time, the spring rod and the first elastic metal strip and the second elastic metal strip can be fitted on the surface of the square or round concrete pile to apply pressure to it, so that the concrete pile is evenly stressed and the accuracy of the bending test is improved. The first elastic metal strip and the bottom of the spring rod are movably connected by T-bolts, so that the first elastic metal strip will not collapse and separate from the bottom of the spring rod when it is bent. Then, the first elastic metal strip and the second elastic metal strip are connected by a supporting spring. The scalability of the supporting spring can increase the bending amplitude of the second elastic metal strip, thereby improving the adaptability to the concrete pile. The present invention also enables the bending test of square concrete piles and round concrete piles of different thicknesses to be performed through a fixed component. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0018] in:

[0019] Figure 1 This is a schematic diagram of the overall structure of a prestressed concrete sheet pile bending test rig;

[0020] Figure 2 for Figure 1 A schematic diagram of the structure enlargement in the middle;

[0021] Figure 3 for Figure 1 A magnified schematic diagram of the structure at B in the middle;

[0022] Figure 4 A schematic diagram of the connection structure of a loading component in a prestressed concrete sheet pile bending test rig;

[0023] Figure 5 is Figure 4 Schematic enlarged view of the structure at position C in

[0024] Figure 6 Schematic connection structure diagram of the loading component and the fixing component in a flexural test bench for prestressed concrete sheet piles

[0025] Figure 7 is Figure 6 Schematic enlarged view of the structure at position D in

[0026] Figure 8 Schematic connection structure diagram of the fixing component in a flexural test bench for prestressed concrete sheet piles

[0027] Figure 9 is Figure 8 Schematic enlarged view of the structure at position E in

[0028] Figure 10 is Figure 9 Schematic enlarged view of the structure at position F in

[0029] In the figure:

[0030] 1. Vertical beam; 2. Upper cross beam; 3. Lower cross beam; 4. Bearing frame;

[0031] 5. Fixing component; 51. Bearing block; 52. Slide block; 53. Slide groove; 54. Central column; 55. Return spring; 56. Rubber layer;

[0032] 6. Locking component; 61. Jack; 62. Cross bar; 63. Push-pull rod; 64. First gas collecting pipe; 65. First piston; 66. Suction hole; 67. Air duct; 68. Second gas collecting pipe; 69. Pressure valve; 610. Second piston; 611. Pressing rod; 612. Pressing plate; 613. Locking head; 614. Fixed block; 615. Limit post;

[0033] 7. Loading component; 71. Load distribution beam; 72. Spring rod; 73. First elastic metal strip; 74. T-shaped bolt; 75. Support spring; 76. Second elastic metal strip; 77. Rubber strip. Specific implementation mode

[0034] In order to make the invention purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0035] Embodiment

[0036] like Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, a prestressed concrete sheet pile bending test pedestal comprises a vertical beam 1, wherein the vertical beam 1 is a pair and symmetrically arranged, the upper ends of the pair of vertical beams 1 are fixedly connected to an upper cross beam 2, the lower ends of the pair of vertical beams 1 are fixedly connected to a lower cross beam 3, the pair of vertical beams 1, the upper cross beam 2 and the lower cross beam 3 form a U-shaped frame, the lower cross beam 3 is fixedly connected to a pair of bearing frames 4, the bearing frames 4 are provided with a fixing assembly 5 for carrying concrete piles of different shapes, the fixing assembly 5 is provided with a locking assembly 6 for locking the fixing assembly 5 above, the upper cross beam 2 is provided with a loading assembly 7 for applying pressure to the concrete pile, the loading assembly 7 comprises a load distribution beam 71, the lower end surface of the load distribution beam 71 is fixedly connected to a plurality of spring rods 72, a No. 1 elastic metal strip 73 is provided below the spring rod 72, and the No. 1 elastic metal strip 73 connects the lower ends of the plurality of spring rods 72 in series;

[0037] The lower end surface of the spring rod 72 is fixedly connected with a T-shaped bolt 74, and the No. 1 elastic metal strip 73 is movably connected to the spring rod 72 through the T-shaped bolt 74. A support spring 75 is nested outside the T-shaped bolt 74. The upper end of the support spring 75 is fixedly connected to the No. 1 elastic metal strip 73, and the lower end of the support spring 75 is fixedly connected to the No. 2 elastic metal strip 76. The lower end surface of the No. 2 elastic metal strip 76 is fixedly connected with a rubber strip 77.

[0038] In the embodiment, after the jack 61 starts working, it drives the load distribution beam 71 to move toward the concrete pile, and the load distribution beam 71 drives the spring rod 72 to move downward, and the spring rod 72 drives the first elastic metal strip 73, the second elastic metal strip 76 and the rubber strip 77 to contact the concrete pile, applying downward pressure to the concrete pile.

[0039] It should be noted that the contact between the rubber strip 77 and the surface of the concrete pile can increase the friction force, have an anti-slip effect, and improve the stability during the loading process.

[0040] It should also be noted that the spring rod 72 and the No. 1 elastic metal strip 73 and the No. 2 elastic metal strip 76 can cooperate to fit on the surface of the square or round concrete pile to apply pressure thereto, so that the concrete pile is evenly stressed and the accuracy of the bending test is improved.

[0041] It should also be noted that the bottom of the first elastic metal strip 73 and the spring rod 72 are movably connected by the T-shaped bolt 74, so that when the first elastic metal strip 73 is bent, it will not break away from the bottom of the spring rod 72. Then, the first elastic metal strip 73 and the second elastic metal strip 76 are connected by the support spring 75. The stretchability of the support spring 75 can increase the bending amplitude of the second elastic metal strip 76, improving the adaptability to the concrete pile.

[0042] As Figure 1 , Figure 3 , Figure 8 and Figure 9 shown, the fixing component 5 includes bearing blocks 51. There are a pair of bearing blocks 51 and they are symmetrically arranged. Calibration holes are formed on the adjacent surfaces of the pair of bearing blocks 51. A central column 54 is fixedly connected in the calibration hole of one of the bearing blocks 51. The central column 54 abuts against the bottom of the calibration hole in the other bearing block 51. A return spring 55 is nested on the central column 54. The two ends of the return spring 55 are respectively fixedly connected in the two calibration holes of the symmetric bearing blocks 51.

[0043] The lower end surface of the bearing block 51 is fixedly connected with a slider 52. A chute 53 is arranged below the bearing block 51. The chute 53 is formed on the upper end surface of the bearing frame 4. The slider 52 is slidably connected in the chute 53.

[0044] The upper end surface of the bearing block 51 is concave for fitting with the concrete pile. A rubber layer 56 is arranged on the concave surface of the bearing block 51.

[0045] In the embodiment, the concrete pile to be tested is placed on the bearing block 51. If it is a square concrete pile, the two ends of the concrete pile can be directly placed on the bearing blocks 51 at both ends, and the bearing blocks 51 will not move (the thickness of the square concrete pile needs to be greater than the size of the concave surface of the bearing block 51).

[0046] When the concrete pile is circular, when the two ends of the concrete pile are placed on the bearing blocks 51 at both ends, due to the pressure from the concrete pile on the concave surface of the bearing block 51 to both sides, the bearing block 51 follows the slider 52 and slides to both sides in the chute 53, and the return spring 55 is stretched. The central column 54 plays a role in limiting and protecting. Finally, the bearing block 51 stops sliding. At this time, the surface of the concrete pile is in fitting contact with the rubber layer 56 on the concave surface of the bearing block 51.

[0047] It should be noted that the fixing component 5 can carry square concrete piles and at the same time can carry circular concrete piles with different thicknesses, and can stably carry them without sliding when loading the concrete pile.

[0048] AsFigure 1 , Figure 3 , Figure 4 , Figure 8 , Figure 9 and Figure 10 As shown in Figure 8 , Figure 9 and Figure 10 , the locking assembly 6 is fixedly connected to the lower end face of the upper cross beam 2. The locking assembly 6 includes a jack 61 which is fixedly connected to the lower end face of the upper cross beam 2. The output end of the jack 61 is fixedly connected with a cross bar 62. The lower end face of the cross bar 62 is fixedly connected with a push-pull rod 63. Below the push-pull rod 63 is provided a first gas collecting pipe 64 which is fixedly connected to the inner wall of the vertical beam 1. The lower end of the push-pull rod 63 extends into the first gas collecting pipe 64 and is fixedly connected with a first piston 65. The first piston 65 is slidably connected inside the first gas collecting pipe 64. The bottom of the first gas collecting pipe 64 is fixedly connected with a gas guide pipe 67. On one side of the bottom of the first gas collecting pipe 64 is fixedly connected with an air suction hole 66. A one-way valve is arranged in the air suction hole 66, and this one-way valve can only let air in and cannot let air out;

[0049] One side of the bearing block 51 is fixedly connected with a second gas collecting pipe 68. One end of the gas guide pipe 67 is fixedly connected to the upper end of the second gas collecting pipe 68. A second piston 610 is slidably connected inside the second gas collecting pipe 68. On one side of the upper end part of the second gas collecting pipe 68 is fixedly connected with a pressure valve 69. The height of the pressure valve 69 is always higher than the height of the second piston 610. The lower end of the second piston 610 is fixedly connected with a pressure rod 611. The lower end of the pressure rod 611 extends out of the second gas collecting pipe 68 and is fixedly connected with a pressing plate 612;

[0050] The pressing plate 612 is slidably connected to one side of the bearing block 51. Below the pressing plate 612 is provided a locking head 613 which is movably connected to one side of the bearing block 51 by a torsion spring. On one side of the locking head 613 is provided a fixing block 614 which is fixedly connected to the upper end face of the bearing frame 4. The side face of the fixing block 614 is fixedly connected with a plurality of limiting columns 615. The locking head 613 cooperates with the limiting columns 615.

[0051] In the embodiment, after the concrete pile is placed, the jack 61 is started. The jack 61 drives the cross bar 62 to descend. The cross bar 62 drives the push-pull rod 63 to drive the first piston 65 to slide downward in the first gas collecting pipe 64. The first piston 65 fills the gas into the second gas collecting pipe 68 through the gas guide pipe 67. After the gas enters the second gas collecting pipe 68, it will push the second piston 610 to drive the pressure rod 611 to move downward. The pressure rod 611 drives the pressing plate 612 to squeeze the locking head 613, so that the locking head 613 buckles on the limiting columns 615. At this time, the two bearing blocks 51 are limited and cannot move.

[0052] It should be noted that when the air pressure in the second gas collecting pipe 68 is too high, the pressure valve 69 will be triggered to exhaust.

[0053] After the bending test is completed, the jack 61 contracts, driving the cross bar 62 and the push-pull rod 63 to move upward and reset. At this time, the first piston 65 slides upward and resets in the first gas collecting pipe 64 (the suction hole 66 intakes air). After the second piston 610 in the second gas collecting pipe 68 is no longer under gas pressure, it moves upward and resets, simultaneously driving the pressure rod 611 and the pressing plate 612 away from the locking head 613. The locking head 613 rotates and resets under the drive of the torsion spring. The two bearing blocks 51 are no longer limited. When the concrete pile is removed from the bearing blocks 51, the two bearing blocks 51 are not under the pressure of the concrete pile. Therefore, the return spring 55 contracts, driving the two bearing blocks 51 to move towards each other to complete the reset.

[0054] The working process is as follows:

[0055] First, various testing instruments are arranged at appropriate positions. Subsequently, both ends of the concrete pile to be tested are respectively placed on the bearing blocks 51. The two ends of the square concrete pile can be directly placed on the bearing blocks 51 at both ends. The circular concrete pile exerts pressure on the concave surfaces of the bearing blocks 51 towards both sides, causing the bearing blocks 51 to slide towards both sides along with the sliders 52 in the sliding grooves 53. Eventually, the bearing blocks 51 stop sliding. At this time, the surface of the concrete pile is in contact with the rubber layer 56 on the concave surfaces of the bearing blocks 51. After the concrete pile is placed, the jack 61 is started. The jack 61 drives the cross bar 62 to descend. The cross bar 62 drives the push-pull rod 63 to drive the first piston 65 to slide downward in the first gas collecting pipe 64. The first piston 65 fills the gas into the second gas collecting pipe 68 through the air duct 67. After the gas enters the second gas collecting pipe 68, it will push the second piston 610 to drive the pressure rod 611 to move downward. The pressure rod 611 drives the pressing plate 612 to squeeze the locking head 613, causing the locking head 613 to buckle on the limit post 615. At this time, the two bearing blocks 51 are limited and cannot move, and the concrete pile is limited. At this time, the loading test can be started. The jack 61 continues to drive the load distribution beam 71 towards the concrete pile. The load distribution beam 71 drives the spring rod 72 to move downward. The spring rod 72 drives the first elastic metal strip 73, the second elastic metal strip 76, and the rubber strip 77 to contact the concrete pile, applying a downward pressure on the concrete pile. At the same time, the concrete pile is detected in real time through the arranged instruments.

[0056] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope claimed by the present invention. The scope claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A prestressed concrete sheet pile bending test pedestal, comprising a pair of vertical beams (1), wherein the vertical beams (1) are symmetrically arranged, the upper ends of the pair of vertical beams (1) are fixedly connected to an upper cross beam (2), the lower ends of the pair of vertical beams (1) are fixedly connected to a lower cross beam (3), the pair of vertical beams (1), the upper cross beam (2) and the lower cross beam (3) form a U-shaped frame, characterized in that: A pair of bearing frames (4) are fixedly connected to the lower cross beam (3), a fixing assembly (5) for bearing concrete piles of different shapes is provided on the bearing frame (4), a locking assembly (6) for locking the fixing assembly (5) is provided above the fixing assembly (5), a loading assembly (7) for applying pressure to the concrete pile is provided on the upper cross beam (2), the loading assembly (7) comprises a load distribution beam (71), a plurality of spring rods (72) are fixedly connected to the lower end surface of the load distribution beam (71), a first elastic metal strip (73) is provided below the spring rod (72), and the first elastic metal strip (73) connects the lower ends of the plurality of spring rods (72) in series; The locking assembly (6) is fixedly connected to the lower end surface of the upper cross beam (2), and the locking assembly (6) comprises a jack (61), the jack (61) is fixedly connected to the lower end surface of the upper cross beam (2), the output end of the jack (61) is fixedly connected to a cross bar (62), the lower end surface of the cross bar (62) is fixedly connected to a push-pull rod (63), a first gas collecting pipe (64) is provided below the push-pull rod (63), and the first gas collecting pipe (64) is fixedly connected to the vertical On the inner wall of the beam (1), the lower end of the push-pull rod (63) extends into the interior of the No. 1 gas collecting pipe (64) and is fixedly connected to the No. 1 piston (65); the No. 1 piston (65) is slidably connected to the interior of the No. 1 gas collecting pipe (64); the bottom of the No. 1 gas collecting pipe (64) is fixedly connected to an air guide pipe (67); one side of the bottom of the No. 1 gas collecting pipe (64) is fixedly connected to an air intake hole (66); a one-way valve is provided in the air intake hole (66); the one-way valve can only allow air to enter but not to exit; The lower end surface of the spring rod (72) is fixedly connected with a T-shaped bolt (74); the first elastic metal strip (73) is movably connected to the spring rod (72) via the T-shaped bolt (74); a support spring (75) is nested around the periphery of the T-shaped bolt (74); the upper end of the support spring (75) is fixedly connected to the first elastic metal strip (73); and the lower end of the support spring (75) is fixedly connected to the second elastic metal strip (76).

2. The prestressed concrete sheet pile bending test pedestal as claimed in claim 1, characterized in that: The fixing assembly (5) comprises a bearing block (51), wherein a pair of the bearing blocks (51) are provided and are symmetrically arranged, and calibration holes are provided on adjacent surfaces of the pair of bearing blocks (51), wherein a central column (54) is fixedly connected to the calibration hole in one of the bearing blocks (51), and the central column (54) abuts against the bottom of the calibration hole in the other bearing block (51), and a return spring (55) is embedded in the central column (54), and the two ends of the return spring (55) are respectively fixedly connected to the two calibration holes in the symmetrical bearing blocks (51).

3. The prestressed concrete sheet pile bending test pedestal as claimed in claim 2, characterized in that: The lower end surface of the bearing block (51) is fixedly connected to a sliding block (52), a sliding groove (53) is provided below the bearing block (51), the sliding groove (53) is opened on the upper end surface of the bearing frame (4), and the sliding block (52) is slidably connected in the sliding groove (53).

4. The prestressed concrete sheet pile bending test pedestal as claimed in claim 3, characterized in that: The upper end surface of the bearing block (51) is in a concave shape and is used to fit with the concrete pile. A rubber layer (56) is provided on the concave surface of the bearing block (51).

5. The prestressed concrete sheet pile bending test pedestal as claimed in claim 4, characterized in that: A No. 2 gas collecting pipe (68) is fixedly connected to one side of the bearing block (51), one end of the gas guide pipe (67) is fixedly connected to the upper end of the No. 2 gas collecting pipe (68), a No. 2 piston (610) is slidably connected to the interior of the No. 2 gas collecting pipe (68), a pressure valve (69) is fixedly connected to one side of the upper end of the No. 2 gas collecting pipe (68), the height of the pressure valve (69) is always higher than the height of the No. 2 piston (610), a pressure rod (611) is fixedly connected to the lower end of the No. 2 piston (610), and the lower end of the pressure rod (611) extends out of the No. 2 gas collecting pipe (68) and is fixedly connected to a pressure plate (612).

6. The prestressed concrete sheet pile bending test pedestal as claimed in claim 5, characterized in that: The pressure plate (612) is slidably connected to one side of the bearing block (51); a locking head (613) is provided below the pressure plate (612); the locking head (613) is movably connected to one side of the bearing block (51) by a torsion spring; a fixing block (614) is provided on one side of the locking head (613); the fixing block (614) is fixedly connected to the upper end surface of the bearing frame (4); a plurality of limiting columns (615) are fixedly connected to the side surface of the fixing block (614); the locking head (613) and the limiting columns (615) cooperate with each other.

7. The prestressed concrete sheet pile bending test pedestal as claimed in claim 6, characterized in that: A rubber strip (77) is fixedly connected to the lower end surface of the second elastic metal strip (76).

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